--- _id: '12716' abstract: - lang: eng text: "The process of detecting and evaluating sensory information to guide behaviour is termed perceptual decision-making (PDM), and is critical for the ability of an organism to interact with its external world. Individuals with autism, a neurodevelopmental condition primarily characterised by social and communication difficulties, frequently exhibit altered sensory processing and PDM difficulties are widely reported. Recent technological advancements have pushed forward our understanding of the genetic changes accompanying this condition, however our understanding of how these mutations affect the function of specific neuronal circuits and bring about the corresponding behavioural changes remains limited. Here, we use an innate PDM task, the looming avoidance response (LAR) paradigm, to identify a convergent behavioural abnormality across three molecularly distinct genetic mouse models of autism (Cul3, Setd5 and Ptchd1). Although mutant mice can rapidly detect threatening visual stimuli, their responses are consistently delayed, requiring longer to initiate an appropriate response than their wild-type siblings. Mutant animals show abnormal adaptation in both their stimulus- evoked escape responses and exploratory dynamics following repeated stimulus presentations. Similarly delayed behavioural responses are observed in wild-type animals when faced with more ambiguous threats, suggesting the mutant phenotype could arise from a dysfunction in the flexible control of this PDM process.\r\nOur knowledge of the core neuronal circuitry mediating the LAR facilitated a detailed dissection of the neuronal mechanisms underlying the behavioural impairment. In vivo extracellular recording revealed that visual responses were unaffected within a key brain region for the rapid processing of visual threats, the superior colliculus (SC), indicating that the behavioural delay was unlikely to originate from sensory impairments. Delayed behavioural responses were recapitulated in the Setd5 model following optogenetic stimulation of the excitatory output neurons of the SC, which are known to mediate escape initiation through the activation of cells in the underlying dorsal periaqueductal grey (dPAG). In vitro patch-clamp recordings of dPAG cells uncovered a stark hypoexcitability phenotype in two out of the three genetic models investigated (Setd5 and Ptchd1), that in Setd5, is mediated by the misregulation of voltage-gated potassium channels. Overall, our results show that the ability to use visual information to drive efficient escape responses is impaired in three diverse genetic mouse models of autism and that, in one of the models studied, this behavioural delay likely originates from differences in the intrinsic excitability of a key subcortical node, the dPAG. Furthermore, this work showcases the use of an innate behavioural paradigm to mechanistically dissect PDM processes in autism." acknowledged_ssus: - _id: PreCl - _id: Bio - _id: LifeSc - _id: M-Shop - _id: CampIT alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Laura full_name: Burnett, Laura id: 3B717F68-F248-11E8-B48F-1D18A9856A87 last_name: Burnett orcid: 0000-0002-8937-410X citation: ama: Burnett L. To flee, or not to flee? Using innate defensive behaviours to investigate rapid perceptual decision-making through subcortical circuits in mouse models of autism. 2023. doi:10.15479/at:ista:12716 apa: Burnett, L. (2023). To flee, or not to flee? Using innate defensive behaviours to investigate rapid perceptual decision-making through subcortical circuits in mouse models of autism. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12716 chicago: Burnett, Laura. “To Flee, or Not to Flee? Using Innate Defensive Behaviours to Investigate Rapid Perceptual Decision-Making through Subcortical Circuits in Mouse Models of Autism.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:12716. ieee: L. Burnett, “To flee, or not to flee? Using innate defensive behaviours to investigate rapid perceptual decision-making through subcortical circuits in mouse models of autism,” Institute of Science and Technology Austria, 2023. ista: Burnett L. 2023. To flee, or not to flee? Using innate defensive behaviours to investigate rapid perceptual decision-making through subcortical circuits in mouse models of autism. Institute of Science and Technology Austria. mla: Burnett, Laura. To Flee, or Not to Flee? Using Innate Defensive Behaviours to Investigate Rapid Perceptual Decision-Making through Subcortical Circuits in Mouse Models of Autism. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:12716. short: L. Burnett, To Flee, or Not to Flee? Using Innate Defensive Behaviours to Investigate Rapid Perceptual Decision-Making through Subcortical Circuits in Mouse Models of Autism, Institute of Science and Technology Austria, 2023. date_created: 2023-03-08T15:19:45Z date_published: 2023-03-10T00:00:00Z date_updated: 2023-04-05T10:59:04Z day: '10' ddc: - '599' - '573' degree_awarded: PhD department: - _id: GradSch - _id: MaJö doi: 10.15479/at:ista:12716 ec_funded: 1 file: - access_level: closed checksum: 6c6d9cc2c4cdacb74e6b1047a34d7332 content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document creator: lburnett date_created: 2023-03-08T15:08:46Z date_updated: 2023-03-08T15:08:46Z file_id: '12717' file_name: Burnett_Thesis_2023.docx file_size: 23029260 relation: source_file - access_level: open_access checksum: cebc77705288bf4382db9b3541483cd0 content_type: application/pdf creator: lburnett date_created: 2023-03-08T15:08:46Z date_updated: 2023-03-08T15:08:46Z file_id: '12718' file_name: Burnett_Thesis_2023_pdfA.pdf file_size: 11959869 relation: main_file success: 1 file_date_updated: 2023-03-08T15:08:46Z has_accepted_license: '1' language: - iso: eng month: '03' oa: 1 oa_version: Published Version page: '178' project: - _id: 2634E9D2-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '756502' name: Circuits of Visual Attention publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria status: public supervisor: - first_name: Maximilian A full_name: Jösch, Maximilian A id: 2BD278E6-F248-11E8-B48F-1D18A9856A87 last_name: Jösch orcid: 0000-0002-3937-1330 title: To flee, or not to flee? Using innate defensive behaviours to investigate rapid perceptual decision-making through subcortical circuits in mouse models of autism type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2023' ... --- _id: '12781' abstract: - lang: eng text: "Most energy in humans is produced in form of ATP by the mitochondrial respiratory chain consisting of several protein assemblies embedded into lipid membrane (complexes I-V). Complex I is the first and the largest enzyme of the respiratory chain which is essential for energy production. It couples the transfer of two electrons from NADH to ubiquinone with proton translocation across bacterial or inner mitochondrial membrane. The coupling mechanism between electron transfer and proton translocation is one of the biggest enigma in bioenergetics and structural biology. Even though the enzyme has been studied for decades, only recent technological advances in cryo-EM allowed its extensive structural investigation. \r\n\r\nComplex I from E.coli appears to be of special importance because it is a perfect model system with a rich mutant library, however the structure of the entire complex was unknown. In this thesis I have resolved structures of the minimal complex I version from E. coli in different states including reduced, inhibited, under reaction turnover and several others. Extensive structural analyses of these structures and comparison to structures from other species allowed to derive general features of conformational dynamics and propose a universal coupling mechanism. The mechanism is straightforward, robust and consistent with decades of experimental data available for complex I from different species. \r\n\r\nCyanobacterial NDH (cyanobacterial complex I) is a part of broad complex I superfamily and was studied as well in this thesis. It plays an important role in cyclic electron transfer (CET), during which electrons are cycled within PSI through ferredoxin and plastoquinone to generate proton gradient without NADPH production. Here, I solved structure of NDH and revealed additional state, which was not observed before. The novel “resting” state allowed to propose the mechanism of CET regulation. Moreover, conformational dynamics of NDH resembles one in complex I which suggest more broad universality of the proposed coupling mechanism.\r\n\r\nIn summary, results presented here helped to interpret decades of experimental data for complex I and contributed to fundamental mechanistic understanding of protein function.\r\n" acknowledged_ssus: - _id: EM-Fac alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Vladyslav full_name: Kravchuk, Vladyslav id: 4D62F2A6-F248-11E8-B48F-1D18A9856A87 last_name: Kravchuk citation: ama: Kravchuk V. Structural and mechanistic study of bacterial complex I and its cyanobacterial ortholog. 2023. doi:10.15479/at:ista:12781 apa: Kravchuk, V. (2023). Structural and mechanistic study of bacterial complex I and its cyanobacterial ortholog. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12781 chicago: Kravchuk, Vladyslav. “Structural and Mechanistic Study of Bacterial Complex I and Its Cyanobacterial Ortholog.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:12781. ieee: V. Kravchuk, “Structural and mechanistic study of bacterial complex I and its cyanobacterial ortholog,” Institute of Science and Technology Austria, 2023. ista: Kravchuk V. 2023. Structural and mechanistic study of bacterial complex I and its cyanobacterial ortholog. Institute of Science and Technology Austria. mla: Kravchuk, Vladyslav. Structural and Mechanistic Study of Bacterial Complex I and Its Cyanobacterial Ortholog. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:12781. short: V. Kravchuk, Structural and Mechanistic Study of Bacterial Complex I and Its Cyanobacterial Ortholog, Institute of Science and Technology Austria, 2023. date_created: 2023-03-31T12:24:42Z date_published: 2023-03-23T00:00:00Z date_updated: 2023-08-04T08:54:51Z day: '23' ddc: - '570' - '572' degree_awarded: PhD department: - _id: GradSch - _id: LeSa doi: 10.15479/at:ista:12781 ec_funded: 1 file: - access_level: closed checksum: 5ebb6345cb4119f93460c81310265a6d content_type: application/pdf creator: vkravchu date_created: 2023-04-19T14:33:41Z date_updated: 2023-04-19T14:33:41Z embargo: 2024-04-20 embargo_to: local file_id: '12852' file_name: VladyslavKravchuk_PhD_Thesis_PostSub_Final_1.pdf file_size: 6071553 relation: main_file - access_level: closed checksum: c12055c48411d030d2afa51de2166221 content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document creator: vkravchu date_created: 2023-04-19T14:33:52Z date_updated: 2023-04-20T07:02:59Z embargo: 2024-04-20 embargo_to: local file_id: '12853' file_name: VladyslavKravchuk_PhD_Thesis_PostSub_Final.docx file_size: 19468766 relation: source_file file_date_updated: 2023-04-20T07:02:59Z has_accepted_license: '1' language: - iso: eng month: '03' oa_version: Published Version page: '127' project: - _id: 238A0A5A-32DE-11EA-91FC-C7463DDC885E grant_number: '25541' name: 'Structural characterization of E. coli complex I: an important mechanistic model' - _id: 627abdeb-2b32-11ec-9570-ec31a97243d3 call_identifier: H2020 grant_number: '101020697' name: Structure and mechanism of respiratory chain molecular machines publication_identifier: isbn: - 978-3-99078-029-9 issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '12138' relation: part_of_dissertation status: public status: public supervisor: - first_name: Leonid A full_name: Sazanov, Leonid A id: 338D39FE-F248-11E8-B48F-1D18A9856A87 last_name: Sazanov orcid: 0000-0002-0977-7989 title: Structural and mechanistic study of bacterial complex I and its cyanobacterial ortholog type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2023' ... --- _id: '13074' abstract: - lang: eng text: "Deep learning has become an integral part of a large number of important applications, and many of the recent breakthroughs have been enabled by the ability to train very large models, capable to capture complex patterns and relationships from the data. At the same time, the massive sizes of modern deep learning models have made their deployment to smaller devices more challenging; this is particularly important, as in many applications the users rely on accurate deep learning predictions, but they only have access to devices with limited memory and compute power. One solution to this problem is to prune neural networks, by setting as many of their parameters as possible to zero, to obtain accurate sparse models with lower memory footprint. Despite the great research progress in obtaining sparse models that preserve accuracy, while satisfying memory and computational constraints, there are still many challenges associated with efficiently training sparse models, as well as understanding their generalization properties.\r\n\r\nThe focus of this thesis is to investigate how the training process of sparse models can be made more efficient, and to understand the differences between sparse and dense models in terms of how well they can generalize to changes in the data distribution. We first study a method for co-training sparse and dense models, at a lower cost compared to regular training. With our method we can obtain very accurate sparse networks, and dense models that can recover the baseline accuracy. Furthermore, we are able to more easily analyze the differences, at prediction level, between the sparse-dense model pairs. Next, we investigate the generalization properties of sparse neural networks in more detail, by studying how well different sparse models trained on a larger task can adapt to smaller, more specialized tasks, in a transfer learning scenario. Our analysis across multiple pruning methods and sparsity levels reveals that sparse models provide features that can transfer similarly to or better than the dense baseline. However, the choice of the pruning method plays an important role, and can influence the results when the features are fixed (linear finetuning), or when they are allowed to adapt to the new task (full finetuning). Using sparse models with fixed masks for finetuning on new tasks has an important practical advantage, as it enables training neural networks on smaller devices. However, one drawback of current pruning methods is that the entire training cycle has to be repeated to obtain the initial sparse model, for every sparsity target; in consequence, the entire training process is costly and also multiple models need to be stored. In the last part of the thesis we propose a method that can train accurate dense models that are compressible in a single step, to multiple sparsity levels, without additional finetuning. Our method results in sparse models that can be competitive with existing pruning methods, and which can also successfully generalize to new tasks." acknowledged_ssus: - _id: ScienComp alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Elena-Alexandra full_name: Peste, Elena-Alexandra id: 32D78294-F248-11E8-B48F-1D18A9856A87 last_name: Peste citation: ama: Peste E-A. Efficiency and generalization of sparse neural networks. 2023. doi:10.15479/at:ista:13074 apa: Peste, E.-A. (2023). Efficiency and generalization of sparse neural networks. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:13074 chicago: Peste, Elena-Alexandra. “Efficiency and Generalization of Sparse Neural Networks.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:13074. ieee: E.-A. Peste, “Efficiency and generalization of sparse neural networks,” Institute of Science and Technology Austria, 2023. ista: Peste E-A. 2023. Efficiency and generalization of sparse neural networks. Institute of Science and Technology Austria. mla: Peste, Elena-Alexandra. Efficiency and Generalization of Sparse Neural Networks. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:13074. short: E.-A. Peste, Efficiency and Generalization of Sparse Neural Networks, Institute of Science and Technology Austria, 2023. date_created: 2023-05-23T17:07:53Z date_published: 2023-05-23T00:00:00Z date_updated: 2023-08-04T10:33:27Z day: '23' ddc: - '000' degree_awarded: PhD department: - _id: GradSch - _id: DaAl - _id: ChLa doi: 10.15479/at:ista:13074 ec_funded: 1 file: - access_level: open_access checksum: 6b3354968403cb9d48cc5a83611fb571 content_type: application/pdf creator: epeste date_created: 2023-05-24T16:11:16Z date_updated: 2023-05-24T16:11:16Z file_id: '13087' file_name: PhD_Thesis_Alexandra_Peste_final.pdf file_size: 2152072 relation: main_file success: 1 - access_level: closed checksum: 8d0df94bbcf4db72c991f22503b3fd60 content_type: application/zip creator: epeste date_created: 2023-05-24T16:12:59Z date_updated: 2023-05-24T16:12:59Z file_id: '13088' file_name: PhD_Thesis_APeste.zip file_size: 1658293 relation: source_file file_date_updated: 2023-05-24T16:12:59Z has_accepted_license: '1' language: - iso: eng month: '05' oa: 1 oa_version: Published Version page: '147' project: - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program - _id: 268A44D6-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '805223' name: Elastic Coordination for Scalable Machine Learning publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '11458' relation: part_of_dissertation status: public - id: '13053' relation: part_of_dissertation status: public - id: '12299' relation: part_of_dissertation status: public status: public supervisor: - first_name: Christoph full_name: Lampert, Christoph id: 40C20FD2-F248-11E8-B48F-1D18A9856A87 last_name: Lampert orcid: 0000-0001-8622-7887 - first_name: Dan-Adrian full_name: Alistarh, Dan-Adrian id: 4A899BFC-F248-11E8-B48F-1D18A9856A87 last_name: Alistarh orcid: 0000-0003-3650-940X title: Efficiency and generalization of sparse neural networks type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2023' ... --- _id: '12964' abstract: - lang: eng text: "Pattern formation is of great importance for its contribution across different biological behaviours. During developmental processes for example, patterns of chemical gradients are\r\nestablished to determine cell fate and complex tissue patterns emerge to define structures such\r\nas limbs and vascular networks. Patterns are also seen in collectively migrating groups, for\r\ninstance traveling waves of density emerging in moving animal flocks as well as collectively migrating cells and tissues. To what extent these biological patterns arise spontaneously through\r\nthe local interaction of individual constituents or are dictated by higher level instructions is\r\nstill an open question however there is evidence for the involvement of both types of process.\r\nWhere patterns arise spontaneously there is a long standing interest in how far the interplay\r\nof mechanics, e.g. force generation and deformation, and chemistry, e.g. gene regulation\r\nand signaling, contributes to the behaviour. This is because many systems are able to both\r\nchemically regulate mechanical force production and chemically sense mechanical deformation,\r\nforming mechano-chemical feedback loops which can potentially become unstable towards\r\nspatio and/or temporal patterning.\r\nWe work with experimental collaborators to investigate the possibility that this type of\r\ninteraction drives pattern formation in biological systems at different scales. We focus first on\r\ntissue-level ERK-density waves observed during the wound healing response across different\r\nsystems where many previous studies have proposed that patterns depend on polarized cell\r\nmigration and arise from a mechanical flocking-like mechanism. By combining theory with\r\nmechanical and optogenetic perturbation experiments on in vitro monolayers we instead find\r\nevidence for mechanochemical pattern formation involving only scalar bilateral feedbacks\r\nbetween ERK signaling and cell contraction. We perform further modeling and experiment\r\nto study how this instability couples with polar cell migration in order to produce a robust\r\nand efficient wound healing response. In a following chapter we implement ERK-density\r\ncoupling and cell migration in a 2D active vertex model to investigate the interaction of\r\nERK-density patterning with different tissue rheologies and find that the spatio-temporal\r\ndynamics are able to both locally and globally fluidize a tissue across the solid-fluid glass\r\ntransition. In a last chapter we move towards lower spatial scales in the context of subcellular\r\npatterning of the cell cytoskeleton where we investigate the transition between phases of\r\nspatially homogeneous temporal oscillations and chaotic spatio-temporal patterning in the\r\ndynamics of myosin and ROCK activities (a motor component of the actomyosin cytoskeleton\r\nand its activator). Experimental evidence supports an intrinsic chemical oscillator which we\r\nencode in a reaction model and couple to a contractile active gel description of the cell cortex.\r\nThe model exhibits phases of chemical oscillations and contractile spatial patterning which\r\nreproduce many features of the dynamics seen in Drosophila oocyte epithelia in vivo. However,\r\nadditional pharmacological perturbations to inhibit myosin contractility leaves the role of\r\ncontractile instability unclear. We discuss alternative hypotheses and investigate the possibility\r\nof reaction-diffusion instability." alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Daniel R full_name: Boocock, Daniel R id: 453AF628-F248-11E8-B48F-1D18A9856A87 last_name: Boocock orcid: 0000-0002-1585-2631 citation: ama: Boocock DR. Mechanochemical pattern formation across biological scales. 2023. doi:10.15479/at:ista:12964 apa: Boocock, D. R. (2023). Mechanochemical pattern formation across biological scales. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12964 chicago: Boocock, Daniel R. “Mechanochemical Pattern Formation across Biological Scales.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:12964. ieee: D. R. Boocock, “Mechanochemical pattern formation across biological scales,” Institute of Science and Technology Austria, 2023. ista: Boocock DR. 2023. Mechanochemical pattern formation across biological scales. Institute of Science and Technology Austria. mla: Boocock, Daniel R. Mechanochemical Pattern Formation across Biological Scales. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:12964. short: D.R. Boocock, Mechanochemical Pattern Formation across Biological Scales, Institute of Science and Technology Austria, 2023. date_created: 2023-05-15T14:52:36Z date_published: 2023-05-17T00:00:00Z date_updated: 2023-08-04T11:02:40Z day: '17' ddc: - '530' degree_awarded: PhD department: - _id: GradSch - _id: EdHa doi: 10.15479/at:ista:12964 ec_funded: 1 file: - access_level: closed checksum: d51240675fc6dc0e3f5dc0c902695d3a content_type: application/pdf creator: dboocock date_created: 2023-05-17T13:39:54Z date_updated: 2023-05-19T07:04:25Z embargo: 2024-05-17 embargo_to: open_access file_id: '12988' file_name: thesis_boocock.pdf file_size: 40414730 relation: main_file - access_level: closed checksum: 581a2313ffeb40fe77e8a122a25a7795 content_type: application/zip creator: dboocock date_created: 2023-05-17T13:39:53Z date_updated: 2023-05-17T14:35:13Z file_id: '12989' file_name: thesis_boocock.zip file_size: 34338567 relation: source_file file_date_updated: 2023-05-19T07:04:25Z has_accepted_license: '1' language: - iso: eng license: https://creativecommons.org/licenses/by-nc-sa/4.0/ month: '05' oa_version: Published Version page: '146' project: - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program publication_identifier: isbn: - 978-3-99078-032-9 issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '8602' relation: part_of_dissertation status: public status: public supervisor: - first_name: Edouard B full_name: Hannezo, Edouard B id: 3A9DB764-F248-11E8-B48F-1D18A9856A87 last_name: Hannezo orcid: 0000-0001-6005-1561 title: Mechanochemical pattern formation across biological scales tmp: image: /images/cc_by_nc_sa.png legal_code_url: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode name: Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) short: CC BY-NC-SA (4.0) type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2023' ... --- _id: '12885' abstract: - lang: eng text: 'High-performance semiconductors rely upon precise control of heat and charge transport. This can be achieved by precisely engineering defects in polycrystalline solids. There are multiple approaches to preparing such polycrystalline semiconductors, and the transformation of solution-processed colloidal nanoparticles is appealing because colloidal nanoparticles combine low cost with structural and compositional tunability along with rich surface chemistry. However, the multiple processes from nanoparticle synthesis to the final bulk nanocomposites are very complex. They involve nanoparticle purification, post-synthetic modifications, and finally consolidation (thermal treatments and densification). All these properties dictate the final material’s composition and microstructure, ultimately affecting its functional properties. This thesis explores the synthesis, surface chemistry and consolidation of colloidal semiconductor nanoparticles into dense solids. In particular, the transformations that take place during these processes, and their effect on the material’s transport properties are evaluated. ' acknowledged_ssus: - _id: EM-Fac - _id: NanoFab alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Mariano full_name: Calcabrini, Mariano id: 45D7531A-F248-11E8-B48F-1D18A9856A87 last_name: Calcabrini orcid: 0000-0003-4566-5877 citation: ama: 'Calcabrini M. Nanoparticle-based semiconductor solids: From synthesis to consolidation. 2023. doi:10.15479/at:ista:12885' apa: 'Calcabrini, M. (2023). Nanoparticle-based semiconductor solids: From synthesis to consolidation. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12885' chicago: 'Calcabrini, Mariano. “Nanoparticle-Based Semiconductor Solids: From Synthesis to Consolidation.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:12885.' ieee: 'M. Calcabrini, “Nanoparticle-based semiconductor solids: From synthesis to consolidation,” Institute of Science and Technology Austria, 2023.' ista: 'Calcabrini M. 2023. Nanoparticle-based semiconductor solids: From synthesis to consolidation. Institute of Science and Technology Austria.' mla: 'Calcabrini, Mariano. Nanoparticle-Based Semiconductor Solids: From Synthesis to Consolidation. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:12885.' short: 'M. Calcabrini, Nanoparticle-Based Semiconductor Solids: From Synthesis to Consolidation, Institute of Science and Technology Austria, 2023.' date_created: 2023-05-02T07:58:57Z date_published: 2023-04-28T00:00:00Z date_updated: 2023-08-14T07:25:26Z day: '28' ddc: - '546' - '541' degree_awarded: PhD department: - _id: GradSch - _id: MaIb doi: 10.15479/at:ista:12885 ec_funded: 1 file: - access_level: closed checksum: 9347b0e09425f56fdcede5d3528404dc content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document creator: mcalcabr date_created: 2023-05-02T07:43:18Z date_updated: 2023-05-02T07:43:18Z file_id: '12887' file_name: Thesis_Calcabrini.docx file_size: 99627036 relation: source_file - access_level: open_access checksum: 2d188b76621086cd384f0b9264b0a576 content_type: application/pdf creator: mcalcabr date_created: 2023-05-02T07:42:45Z date_updated: 2023-05-02T07:42:45Z file_id: '12888' file_name: Thesis_Calcabrini_pdfa.pdf file_size: 8742220 relation: main_file success: 1 file_date_updated: 2023-05-02T07:43:18Z has_accepted_license: '1' language: - iso: eng month: '04' oa: 1 oa_version: Published Version page: '82' project: - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program publication_identifier: isbn: - 978-3-99078-028-2 issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '10806' relation: part_of_dissertation status: public - id: '10042' relation: part_of_dissertation status: public - id: '12237' relation: part_of_dissertation status: public - id: '9118' relation: part_of_dissertation status: public - id: '10123' relation: part_of_dissertation status: public status: public supervisor: - first_name: Maria full_name: Ibáñez, Maria id: 43C61214-F248-11E8-B48F-1D18A9856A87 last_name: Ibáñez orcid: 0000-0001-5013-2843 title: 'Nanoparticle-based semiconductor solids: From synthesis to consolidation' type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2023' ... --- _id: '12732' abstract: - lang: eng text: "Nonergodic systems, whose out-of-equilibrium dynamics fail to thermalize, provide a fascinating research direction both for fundamental reasons and for application in state of the art quantum devices.\r\nGoing beyond the description of statistical mechanics, ergodicity breaking yields a new paradigm in quantum many-body physics, introducing novel phases of matter with no counterpart at equilibrium.\r\nIn this Thesis, we address different open questions in the field, focusing on disorder-induced many-body localization (MBL) and on weak ergodicity breaking in kinetically constrained models.\r\nIn particular, we contribute to the debate about transport in kinetically constrained models, studying the effect of $U(1)$ conservation and inversion-symmetry breaking in a family of quantum East models.\r\nUsing tensor network techniques, we analyze the dynamics of large MBL systems beyond the limit of exact numerical methods.\r\nIn this setting, we approach the debated topic of the coexistence of localized and thermal eigenstates separated by energy thresholds known as many-body mobility edges.\r\nInspired by recent experiments, our work further investigates the localization of a small bath induced by the coupling to a large localized chain, the so-called MBL proximity effect.\r\n\r\nIn the first Chapter, we introduce a family of particle-conserving kinetically constrained models, inspired by the quantum East model.\r\nThe system we study features strong inversion-symmetry breaking, due to the nature of the correlated hopping.\r\nWe show that these models host so-called quantum Hilbert space fragmentation, consisting of disconnected subsectors in an entangled basis, and further provide an analytical description of this phenomenon.\r\nWe further probe its effect on dynamics of simple product states, showing revivals in fidelity and local observalbes.\r\nThe study of dynamics within the largest subsector reveals an anomalous transient superdiffusive behavior crossing over to slow logarithmic dynamics at later times.\r\nThis work suggests that particle conserving constrained models with inversion-symmetry breaking realize new universality classes of dynamics and invite their further theoretical and experimental studies.\r\n\r\nNext, we use kinetic constraints and disorder to design a model with many-body mobility edges in particle density.\r\nThis feature allows to study the dynamics of localized and thermal states in large systems beyond the limitations of previous studies.\r\nThe time-evolution shows typical signatures of localization at small densities, replaced by thermal behavior at larger densities.\r\nOur results provide evidence in favor of the stability of many-body mobility edges, which was recently challenged by a theoretical argument.\r\nTo support our findings, we probe the mechanism proposed as a cause of delocalization in many-body localized systems with mobility edges suggesting its ineffectiveness in the model studied.\r\n\r\nIn the last Chapter of this Thesis, we address the topic of many-body localization proximity effect.\r\nWe study a model inspired by recent experiments, featuring Anderson localized coupled to a small bath of free hard-core bosons.\r\nThe interaction among the two particle species results in non-trivial dynamics, which we probe using tensor network techniques.\r\nOur simulations show convincing evidence of many-body localization proximity effect when the bath is composed by a single free particle and interactions are strong.\r\nWe furthter observe an anomalous entanglement dynamics, which we explain through a phenomenological theory.\r\nFinally, we extract highly excited eigenstates of large systems, providing supplementary evidence in favor of our findings." acknowledged_ssus: - _id: ScienComp alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Pietro full_name: Brighi, Pietro id: 4115AF5C-F248-11E8-B48F-1D18A9856A87 last_name: Brighi orcid: 0000-0002-7969-2729 citation: ama: Brighi P. Ergodicity breaking in disordered and kinetically constrained quantum many-body systems. 2023. doi:10.15479/at:ista:12732 apa: Brighi, P. (2023). Ergodicity breaking in disordered and kinetically constrained quantum many-body systems. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12732 chicago: Brighi, Pietro. “Ergodicity Breaking in Disordered and Kinetically Constrained Quantum Many-Body Systems.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:12732. ieee: P. Brighi, “Ergodicity breaking in disordered and kinetically constrained quantum many-body systems,” Institute of Science and Technology Austria, 2023. ista: Brighi P. 2023. Ergodicity breaking in disordered and kinetically constrained quantum many-body systems. Institute of Science and Technology Austria. mla: Brighi, Pietro. Ergodicity Breaking in Disordered and Kinetically Constrained Quantum Many-Body Systems. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:12732. short: P. Brighi, Ergodicity Breaking in Disordered and Kinetically Constrained Quantum Many-Body Systems, Institute of Science and Technology Austria, 2023. date_created: 2023-03-17T13:30:48Z date_published: 2023-03-21T00:00:00Z date_updated: 2023-09-20T10:44:12Z day: '21' ddc: - '530' degree_awarded: PhD department: - _id: GradSch - _id: MaSe doi: 10.15479/at:ista:12732 ec_funded: 1 file: - access_level: closed checksum: 5d2de651ef9449c1b8dc27148ca74777 content_type: application/zip creator: pbrighi date_created: 2023-03-23T16:42:56Z date_updated: 2023-03-23T16:42:56Z file_id: '12753' file_name: Thesis_sub_PBrighi.zip file_size: 42167561 relation: source_file - access_level: open_access checksum: 7caa153d4a5b0873a79358787d2dfe1e content_type: application/pdf creator: pbrighi date_created: 2023-03-23T16:43:14Z date_updated: 2023-03-23T16:43:14Z file_id: '12754' file_name: Thesis_PBrighi.pdf file_size: 13977000 relation: main_file success: 1 file_date_updated: 2023-03-23T16:43:14Z has_accepted_license: '1' language: - iso: eng month: '03' oa: 1 oa_version: None page: '158' project: - _id: 23841C26-32DE-11EA-91FC-C7463DDC885E call_identifier: H2020 grant_number: '850899' name: 'Non-Ergodic Quantum Matter: Universality, Dynamics and Control' publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '11470' relation: part_of_dissertation status: public - id: '8308' relation: part_of_dissertation status: public - id: '11469' relation: part_of_dissertation status: public - id: '12750' relation: part_of_dissertation status: public status: public supervisor: - first_name: Maksym full_name: Serbyn, Maksym id: 47809E7E-F248-11E8-B48F-1D18A9856A87 last_name: Serbyn orcid: 0000-0002-2399-5827 title: Ergodicity breaking in disordered and kinetically constrained quantum many-body systems tmp: image: /images/cc_by_nc_sa.png legal_code_url: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode name: Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) short: CC BY-NC-SA (4.0) type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2023' ... --- _id: '12726' abstract: - lang: eng text: "Most motions of many-body systems at any scale in nature with sufficient degrees\r\nof freedom tend to be chaotic; reaching from the orbital motion of planets, the air\r\ncurrents in our atmosphere, down to the water flowing through our pipelines or\r\nthe movement of a population of bacteria. To the observer it is therefore intriguing\r\nwhen a moving collective exhibits order. Collective motion of flocks of birds, schools\r\nof fish or swarms of self-propelled particles or robots have been studied extensively\r\nover the past decades but the mechanisms involved in the transition from chaos to\r\norder remain unclear. Here, the interactions, that in most systems give rise to chaos,\r\nsustain order. In this thesis we investigate mechanisms that preserve, destabilize\r\nor lead to the ordered state. We show that endothelial cells migrating in circular\r\nconfinements transition to a collective rotating state and concomitantly synchronize\r\nthe frequencies of nucleating actin waves within individual cells. Consequently,\r\nthe frequency dependent cell migration speed uniformizes across the population.\r\nComplementary to the WAVE dependent nucleation of traveling actin waves, we\r\nshow that in leukocytes the actin polymerization depending on WASp generates\r\npushing forces locally at stationary patches. Next, in pipe flows, we study methods\r\nto disrupt the self–sustaining cycle of turbulence and therefore relaminarize the\r\nflow. While we find in pulsating flow conditions that turbulence emerges through a\r\nhelical instability during the decelerating phase. Finally, we show quantitatively in\r\nbrain slices of mice that wild-type control neurons can compensate the migratory\r\ndeficits of a genetically modified neuronal sub–population in the developing cortex." acknowledged_ssus: - _id: M-Shop - _id: Bio alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Michael full_name: Riedl, Michael id: 3BE60946-F248-11E8-B48F-1D18A9856A87 last_name: Riedl orcid: 0000-0003-4844-6311 citation: ama: Riedl M. Synchronization in collectively moving active matter. 2023. doi:10.15479/at:ista:12726 apa: Riedl, M. (2023). Synchronization in collectively moving active matter. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12726 chicago: Riedl, Michael. “Synchronization in Collectively Moving Active Matter.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:12726. ieee: M. Riedl, “Synchronization in collectively moving active matter,” Institute of Science and Technology Austria, 2023. ista: Riedl M. 2023. Synchronization in collectively moving active matter. Institute of Science and Technology Austria. mla: Riedl, Michael. Synchronization in Collectively Moving Active Matter. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:12726. short: M. Riedl, Synchronization in Collectively Moving Active Matter, Institute of Science and Technology Austria, 2023. date_created: 2023-03-15T13:22:13Z date_published: 2023-03-23T00:00:00Z date_updated: 2023-11-30T10:55:13Z day: '23' ddc: - '530' degree_awarded: PhD department: - _id: GradSch - _id: BjHo doi: 10.15479/at:ista:12726 file: - access_level: closed checksum: eba0e19fe57a8c15e7aeab55a845efb7 content_type: application/pdf creator: cchlebak date_created: 2023-03-23T12:49:23Z date_updated: 2023-11-24T11:57:46Z description: the main file is missing the bibliography. See new thesis record 14530 for updated files. file_id: '12745' file_name: Thesis_Riedl_2023.pdf file_size: 63734746 relation: main_file - access_level: closed checksum: 0eb7b650cc8ae843bcec7c8a6109ae03 content_type: application/octet-stream creator: cchlebak date_created: 2023-03-23T12:54:34Z date_updated: 2023-09-24T22:30:03Z embargo_to: open_access file_id: '12746' file_name: Thesis_Riedl_2023_source.rar file_size: 339473651 relation: source_file file_date_updated: 2023-11-24T11:57:46Z has_accepted_license: '1' language: - iso: eng month: '03' oa_version: None page: '260' publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '10703' relation: part_of_dissertation status: public - id: '10791' relation: part_of_dissertation status: public - id: '7932' relation: part_of_dissertation status: public - id: '461' relation: part_of_dissertation status: public - id: '14530' relation: new_edition status: public status: public supervisor: - first_name: Björn full_name: Hof, Björn id: 3A374330-F248-11E8-B48F-1D18A9856A87 last_name: Hof orcid: 0000-0003-2057-2754 title: Synchronization in collectively moving active matter type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2023' ... --- _id: '14058' abstract: - lang: eng text: "Females and males across species are subject to divergent selective pressures arising\r\nfrom di↵erent reproductive interests and ecological niches. This often translates into a\r\nintricate array of sex-specific natural and sexual selection on traits that have a shared\r\ngenetic basis between both sexes, causing a genetic sexual conflict. The resolution of\r\nthis conflict mostly relies on the evolution of sex-specific expression of the shared genes,\r\nleading to phenotypic sexual dimorphism. Such sex-specific gene expression is thought\r\nto evolve via modifications of the genetic networks ultimately linked to sex-determining\r\ntranscription factors. Although much empirical and theoretical evidence supports this\r\nstandard picture of the molecular basis of sexual conflict resolution, there still are a\r\nfew open questions regarding the complex array of selective forces driving phenotypic\r\ndi↵erentiation between the sexes, as well as the molecular mechanisms underlying sexspecific adaptation. I address some of these open questions in my PhD thesis.\r\nFirst, how do patterns of phenotypic sexual dimorphism vary within populations,\r\nas a response to the temporal and spatial changes in sex-specific selective forces? To\r\ntackle this question, I analyze the patterns of sex-specific phenotypic variation along\r\nthree life stages and across populations spanning the whole geographical range of Rumex\r\nhastatulus, a wind-pollinated angiosperm, in the first Chapter of the thesis.\r\nSecond, how do gene expression patterns lead to phenotypic dimorphism, and what\r\nare the molecular mechanisms underlying the observed transcriptomic variation? I\r\naddress this question by examining the sex- and tissue-specific expression variation in\r\nnewly-generated datasets of sex-specific expression in heads and gonads of Drosophila\r\nmelanogaster. I additionally used two complementary approaches for the study of the\r\ngenetic basis of sex di↵erences in gene expression in the second and third Chapters of\r\nthe thesis.\r\nThird, how does intersex correlation, thought to be one of the main aspects constraining the ability for the two sexes to decouple, interact with the evolution of sexual\r\ndimorphism? I develop models of sex-specific stabilizing selection, mutation and drift\r\nto formalize common intuition regarding the patterns of covariation between intersex\r\ncorrelation and sexual dimorphism in the fourth Chapter of the thesis.\r\nAlltogether, the work described in this PhD thesis provides useful insights into the\r\nlinks between genetic, transcriptomic and phenotypic layers of sex-specific variation,\r\nand contributes to our general understanding of the dynamics of sexual dimorphism\r\nevolution." alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Gemma full_name: Puixeu Sala, Gemma id: 33AB266C-F248-11E8-B48F-1D18A9856A87 last_name: Puixeu Sala orcid: 0000-0001-8330-1754 citation: ama: 'Puixeu Sala G. The molecular basis of sexual dimorphism: Experimental and theoretical characterization of phenotypic, transcriptomic and genetic patterns of sex-specific adaptation. 2023. doi:10.15479/at:ista:14058' apa: 'Puixeu Sala, G. (2023). The molecular basis of sexual dimorphism: Experimental and theoretical characterization of phenotypic, transcriptomic and genetic patterns of sex-specific adaptation. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:14058' chicago: 'Puixeu Sala, Gemma. “The Molecular Basis of Sexual Dimorphism: Experimental and Theoretical Characterization of Phenotypic, Transcriptomic and Genetic Patterns of Sex-Specific Adaptation.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:14058.' ieee: 'G. Puixeu Sala, “The molecular basis of sexual dimorphism: Experimental and theoretical characterization of phenotypic, transcriptomic and genetic patterns of sex-specific adaptation,” Institute of Science and Technology Austria, 2023.' ista: 'Puixeu Sala G. 2023. The molecular basis of sexual dimorphism: Experimental and theoretical characterization of phenotypic, transcriptomic and genetic patterns of sex-specific adaptation. Institute of Science and Technology Austria.' mla: 'Puixeu Sala, Gemma. The Molecular Basis of Sexual Dimorphism: Experimental and Theoretical Characterization of Phenotypic, Transcriptomic and Genetic Patterns of Sex-Specific Adaptation. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:14058.' short: 'G. Puixeu Sala, The Molecular Basis of Sexual Dimorphism: Experimental and Theoretical Characterization of Phenotypic, Transcriptomic and Genetic Patterns of Sex-Specific Adaptation, Institute of Science and Technology Austria, 2023.' date_created: 2023-08-15T10:20:40Z date_published: 2023-08-15T00:00:00Z date_updated: 2023-12-13T12:15:36Z day: '15' ddc: - '576' degree_awarded: PhD department: - _id: GradSch - _id: NiBa - _id: BeVi doi: 10.15479/at:ista:14058 ec_funded: 1 file: - access_level: closed checksum: 4e44e169f2724ee8c9324cd60bcc2b71 content_type: application/zip creator: gpuixeus date_created: 2023-08-16T18:15:17Z date_updated: 2023-08-17T06:55:24Z file_id: '14075' file_name: Thesis_latex_forpdfa.zip file_size: 10891454 relation: source_file - access_level: open_access checksum: e10b04cd8f3fecc0d9ef6e6868b6e1e8 content_type: application/pdf creator: gpuixeus date_created: 2023-08-18T10:47:55Z date_updated: 2023-08-18T10:47:55Z file_id: '14079' file_name: PhDThesis_PuixeuG.pdf file_size: 19856686 relation: main_file success: 1 file_date_updated: 2023-08-18T10:47:55Z has_accepted_license: '1' language: - iso: eng license: https://creativecommons.org/licenses/by/4.0/ month: '08' oa: 1 oa_version: Published Version page: '230' project: - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program - _id: 9B9DFC9E-BA93-11EA-9121-9846C619BF3A grant_number: '25817' name: 'Sexual conflict: resolution, constraints and biomedical implications' publication_identifier: isbn: - 978-3-99078-035-0 issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '9803' relation: research_data status: public - id: '12933' relation: research_data status: public - id: '6831' relation: part_of_dissertation status: public - id: '14077' relation: part_of_dissertation status: public status: public supervisor: - first_name: Beatriz full_name: Vicoso, Beatriz id: 49E1C5C6-F248-11E8-B48F-1D18A9856A87 last_name: Vicoso orcid: 0000-0002-4579-8306 - first_name: Nicholas H full_name: Barton, Nicholas H id: 4880FE40-F248-11E8-B48F-1D18A9856A87 last_name: Barton orcid: 0000-0002-8548-5240 title: 'The molecular basis of sexual dimorphism: Experimental and theoretical characterization of phenotypic, transcriptomic and genetic patterns of sex-specific adaptation' tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2023' ... --- _id: '14280' abstract: - lang: eng text: "Cell division in Escherichia coli is performed by the divisome, a multi-protein complex composed of more than 30 proteins. The divisome spans from the cytoplasm through the inner membrane to the cell wall and the outer membrane. Divisome assembly is initiated by a cytoskeletal structure, the so-called Z-ring, which localizes at the center of the E. coli cell and determines the position of the future cell septum. The Z-ring is composed of the highly conserved bacterial tubulin homologue FtsZ, which forms treadmilling filaments. These filaments are recruited to the inner membrane by FtsA, a highly conserved bacterial actin homologue. FtsA interacts with other proteins in the periplasm and thus connects the cytoplasmic and periplasmic components of the divisome. \r\nA previous model postulated that FtsA regulates maturation of the divisome by switching from an oligomeric, inactive state to a monomeric and active state. This model was based mostly on in vivo studies, as a biochemical characterization of FtsA has been hampered by difficulties in purifying the protein. Here, we studied FtsA using an in vitro reconstitution approach and aimed to answer two questions: (i) How are dynamics from cytoplasmic, treadmilling FtsZ filaments coupled to proteins acting in the periplasmic space and (ii) How does FtsA regulate the maturation of the divisome?\r\nWe found that the cytoplasmic peptides of the transmembrane proteins FtsN and FtsQ interact directly with FtsA and can follow the spatiotemporal signal of FtsA/Z filaments. When we investigated the underlying mechanism by imaging single molecules of FtsNcyto, we found the peptide to interact transiently with FtsA. An in depth analysis of the single molecule trajectories helped to postulate a model where PG synthases follow the dynamics of FtsZ by a diffusion and capture mechanism. \r\nFollowing up on these findings we were interested in how the self-interaction of FtsA changes when it encounters FtsNcyto and if we can confirm the proposed oligomer-monomer switch. For this, we compared the behavior of the previously identified, hyperactive mutant FtsA R286W with wildtype FtsA. The mutant outperforms WT in mirroring and transmitting the spatiotemporal signal of treadmilling FtsZ filaments. Surprisingly however, we found that this was not due to a difference in the self-interaction strength of the two variants, but a difference in their membrane residence time. Furthermore, in contrast to our expectations, upon binding of FtsNcyto the measured self-interaction of FtsA actually increased. \r\nWe propose that FtsNcyto induces a rearrangement of the oligomeric architecture of FtsA. In further consequence this change leads to more persistent FtsZ filaments which results in a defined signalling zone, allowing formation of the mature divisome. The observed difference between FtsA WT and R286W is due to the vastly different membrane turnover of the proteins. R286W cycles 5-10x faster compared to WT which allows to sample FtsZ filaments at faster frequencies. These findings can explain the observed differences in toxicity for overexpression of FtsA WT and R286W and help to understand how FtsA regulates divisome maturation." acknowledged_ssus: - _id: Bio - _id: LifeSc alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Philipp full_name: Radler, Philipp id: 40136C2A-F248-11E8-B48F-1D18A9856A87 last_name: Radler orcid: '0000-0001-9198-2182 ' citation: ama: Radler P. Spatiotemporal signaling during assembly of the bacterial divisome. 2023. doi:10.15479/at:ista:14280 apa: Radler, P. (2023). Spatiotemporal signaling during assembly of the bacterial divisome. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:14280 chicago: Radler, Philipp. “Spatiotemporal Signaling during Assembly of the Bacterial Divisome.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:14280. ieee: P. Radler, “Spatiotemporal signaling during assembly of the bacterial divisome,” Institute of Science and Technology Austria, 2023. ista: Radler P. 2023. Spatiotemporal signaling during assembly of the bacterial divisome. Institute of Science and Technology Austria. mla: Radler, Philipp. Spatiotemporal Signaling during Assembly of the Bacterial Divisome. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:14280. short: P. Radler, Spatiotemporal Signaling during Assembly of the Bacterial Divisome, Institute of Science and Technology Austria, 2023. date_created: 2023-09-06T10:58:25Z date_published: 2023-09-25T00:00:00Z date_updated: 2024-02-21T12:35:18Z day: '25' ddc: - '572' degree_awarded: PhD department: - _id: GradSch - _id: MaLo doi: 10.15479/at:ista:14280 ec_funded: 1 file: - access_level: closed checksum: 87eef11fbc5c7df0826f12a3a629b444 content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document creator: pradler date_created: 2023-10-04T10:11:53Z date_updated: 2023-10-04T10:28:35Z file_id: '14390' file_name: PhD Thesis_Philipp Radler_20231004.docx file_size: 114932847 relation: source_file - access_level: closed checksum: 3253e099b7126469d941fd9419d68b4f content_type: application/pdf creator: pradler date_created: 2023-10-04T10:11:21Z date_updated: 2023-10-04T10:28:35Z embargo: 2024-10-04 embargo_to: open_access file_id: '14391' file_name: PhD Thesis_Philipp Radler_20231004.pdf file_size: 37838778 relation: main_file file_date_updated: 2023-10-04T10:28:35Z has_accepted_license: '1' keyword: - Cell Division - Reconstitution - FtsZ - FtsA - Divisome - E.coli language: - iso: eng month: '09' oa_version: Published Version page: '156' project: - _id: 2595697A-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '679239' name: Self-Organization of the Bacterial Cell - _id: fc38323b-9c52-11eb-aca3-ff8afb4a011d grant_number: P34607 name: "Understanding bacterial cell division by in vitro\r\nreconstitution" - _id: 2596EAB6-B435-11E9-9278-68D0E5697425 grant_number: ALTF 2015-1163 name: Synthesis of bacterial cell wall - _id: 259B655A-B435-11E9-9278-68D0E5697425 grant_number: LT000824/2016 name: Reconstitution of bacterial cell wall sythesis publication_identifier: isbn: - 978-3-99078-033-6 issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '11373' relation: part_of_dissertation status: public - id: '7387' relation: part_of_dissertation status: public - id: '10934' relation: research_data status: public status: public supervisor: - first_name: Martin full_name: Loose, Martin id: 462D4284-F248-11E8-B48F-1D18A9856A87 last_name: Loose orcid: 0000-0001-7309-9724 title: Spatiotemporal signaling during assembly of the bacterial divisome tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2023' ... --- _id: '12491' abstract: - lang: eng text: "The extracellular matrix (ECM) is a hydrated and complex three-dimensional network consisting of proteins, polysaccharides, and water. It provides structural scaffolding for the cells embedded within it and is essential in regulating numerous physiological processes, including cell migration and proliferation, wound healing, and stem cell fate. \r\nDespite extensive study, detailed structural knowledge of ECM components in physiologically relevant conditions is still rudimentary. This is due to methodological limitations in specimen preparation protocols which are incompatible with keeping large samples, such as the ECM, in their native state for subsequent imaging. Conventional electron microscopy (EM) techniques rely on fixation, dehydration, contrasting, and sectioning. This results in the alteration of a highly hydrated environment and the potential introduction of artifacts. Other structural biology techniques, such as nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography, allow high-resolution analysis of protein structures but only work on homogenous and purified samples, hence lacking contextual information. Currently, no approach exists for the ultrastructural and structural study of extracellular components under native conditions in a physiological, 3D environment. \r\nIn this thesis, I have developed a workflow that allows for the ultrastructural analysis of the ECM in near-native conditions at molecular resolution. The developments I introduced include implementing a novel specimen preparation workflow for cell-derived matrices (CDMs) to render them compatible with ion-beam milling and subsequent high-resolution cryo-electron tomography (ET). \r\nTo this end, I have established protocols to generate CDMs grown over several weeks on EM grids that are compatible with downstream cryo-EM sample preparation and imaging techniques. Characterization of these ECMs confirmed that they contain essential ECM components such as collagen I, collagen VI, and fibronectin I in high abundance and hence represent a bona fide biologically-relevant sample. I successfully optimized vitrification of these specimens by testing various vitrification techniques and cryoprotectants. \r\nIn order to obtain high-resolution molecular insights into the ultrastructure and organization of CDMs, I established cryo-focused ion beam scanning electron microscopy (FIBSEM) on these challenging and complex specimens. I explored different approaches for the creation of thin cryo-lamellae by FIB milling and succeeded in optimizing the cryo-lift-out technique, resulting in high-quality lamellae of approximately 200 nm thickness. \r\nHigh-resolution Cryo-ET of these lamellae revealed for the first time the architecture of native CDM in the context of matrix-secreting cells. This allowed for the in situ visualization of fibrillar matrix proteins such as collagen, laying the foundation for future structural and ultrastructural characterization of these proteins in their near-native environment. \r\nIn summary, in this thesis, I present a novel workflow that combines state-of-the-art cryo-EM specimen preparation and imaging technologies to permit characterization of the ECM, an important tissue component in higher organisms. This innovative and highly versatile workflow will enable addressing far-reaching questions on ECM architecture, composition, and reciprocal ECM-cell interactions." acknowledged_ssus: - _id: EM-Fac - _id: LifeSc - _id: Bio alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Bettina full_name: Zens, Bettina id: 45FD126C-F248-11E8-B48F-1D18A9856A87 last_name: Zens orcid: 0000-0002-9561-1239 citation: ama: Zens B. Ultrastructural characterization of natively preserved extracellular matrix by cryo-electron tomography. 2023. doi:10.15479/at:ista:12491 apa: Zens, B. (2023). Ultrastructural characterization of natively preserved extracellular matrix by cryo-electron tomography. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12491 chicago: Zens, Bettina. “Ultrastructural Characterization of Natively Preserved Extracellular Matrix by Cryo-Electron Tomography.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:12491. ieee: B. Zens, “Ultrastructural characterization of natively preserved extracellular matrix by cryo-electron tomography,” Institute of Science and Technology Austria, 2023. ista: Zens B. 2023. Ultrastructural characterization of natively preserved extracellular matrix by cryo-electron tomography. Institute of Science and Technology Austria. mla: Zens, Bettina. Ultrastructural Characterization of Natively Preserved Extracellular Matrix by Cryo-Electron Tomography. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:12491. short: B. Zens, Ultrastructural Characterization of Natively Preserved Extracellular Matrix by Cryo-Electron Tomography, Institute of Science and Technology Austria, 2023. date_created: 2023-02-02T14:50:20Z date_published: 2023-02-02T00:00:00Z date_updated: 2024-03-25T23:30:05Z day: '02' ddc: - '570' degree_awarded: PhD department: - _id: GradSch - _id: FlSc doi: 10.15479/at:ista:12491 file: - access_level: open_access checksum: 069d87f025e0799bf9e3c375664264f2 content_type: application/pdf creator: bzens date_created: 2023-02-07T13:07:38Z date_updated: 2024-02-08T23:30:04Z embargo: 2024-02-07 file_id: '12527' file_name: PhDThesis_BettinaZens_2023_final.pdf file_size: 23082464 relation: main_file - access_level: closed checksum: 8c66ed203495d6e078ed1002a866520c content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document creator: bzens date_created: 2023-02-07T13:09:05Z date_updated: 2024-02-08T23:30:04Z embargo_to: open_access file_id: '12528' file_name: PhDThesis_BettinaZens_2023_final.docx file_size: 106169509 relation: source_file file_date_updated: 2024-02-08T23:30:04Z has_accepted_license: '1' keyword: - cryo-EM - cryo-ET - FIB milling - method development - FIBSEM - extracellular matrix - ECM - cell-derived matrices - CDMs - cell culture - high pressure freezing - HPF - structural biology - tomography - collagen language: - iso: eng month: '02' oa: 1 oa_version: Published Version page: '187' project: - _id: eba3b5f6-77a9-11ec-83b8-cf0905748aa3 name: Integrated visual proteomics of reciprocal cell-extracellular matrix interactions - _id: 059B463C-7A3F-11EA-A408-12923DDC885E name: NÖ-Fonds Preis für die Jungforscherin des Jahres am IST Austria publication_identifier: isbn: - 978-3-99078-027-5 issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '8586' relation: part_of_dissertation status: public status: public supervisor: - first_name: Florian KM full_name: Schur, Florian KM id: 48AD8942-F248-11E8-B48F-1D18A9856A87 last_name: Schur orcid: 0000-0003-4790-8078 title: Ultrastructural characterization of natively preserved extracellular matrix by cryo-electron tomography type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2023' ... --- _id: '12470' abstract: - lang: eng text: "The brain is an exceptionally sophisticated organ consisting of billions of cells and trillions of \r\nconnections that orchestrate our cognition and behavior. To decode its complex connectivity, it is \r\npivotal to disentangle its intricate architecture spanning from cm-sized circuits down to tens of \r\nnm-small synapses.\r\nTo achieve this goal, I developed CATS – Comprehensive Analysis of nervous Tissue across \r\nScales, a versatile toolbox for obtaining a holistic view of nervous tissue context with (super\x02resolution) fluorescence microscopy. CATS combines comprehensive labeling of the extracellular\r\nspace, that is compatible with chemical fixation, with information on molecular markers, super\x02resolved data acquisition and machine-learning based data analysis for segmentation and synapse \r\nidentification.\r\nI used CATS to analyze key features of nervous tissue connectivity, ranging from whole tissue \r\narchitecture, neuronal in- and output-fields, down to synapse morphology.\r\nFocusing on the hippocampal circuitry, I quantified synaptic transmission properties of mossy \r\nfiber boutons and analyzed the connectivity pattern of dentate gyrus granule cells with CA3 \r\npyramidal neurons. This shows that CATS is a viable tool to study hallmarks of neuronal \r\nconnectivity with light microscopy." acknowledged_ssus: - _id: Bio - _id: LifeSc - _id: PreCl - _id: EM-Fac - _id: M-Shop - _id: ScienComp alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Julia M full_name: Michalska, Julia M id: 443DB6DE-F248-11E8-B48F-1D18A9856A87 last_name: Michalska orcid: 0000-0003-3862-1235 citation: ama: Michalska JM. A versatile toolbox for the comprehensive analysis of nervous tissue organization with light microscopy. 2023. doi:10.15479/at:ista:12470 apa: Michalska, J. M. (2023). A versatile toolbox for the comprehensive analysis of nervous tissue organization with light microscopy. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12470 chicago: Michalska, Julia M. “A Versatile Toolbox for the Comprehensive Analysis of Nervous Tissue Organization with Light Microscopy.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:12470. ieee: J. M. Michalska, “A versatile toolbox for the comprehensive analysis of nervous tissue organization with light microscopy,” Institute of Science and Technology Austria, 2023. ista: Michalska JM. 2023. A versatile toolbox for the comprehensive analysis of nervous tissue organization with light microscopy. Institute of Science and Technology Austria. mla: Michalska, Julia M. A Versatile Toolbox for the Comprehensive Analysis of Nervous Tissue Organization with Light Microscopy. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:12470. short: J.M. Michalska, A Versatile Toolbox for the Comprehensive Analysis of Nervous Tissue Organization with Light Microscopy, Institute of Science and Technology Austria, 2023. date_created: 2023-01-31T15:10:53Z date_published: 2023-01-09T00:00:00Z date_updated: 2023-08-31T12:26:58Z day: '09' ddc: - '610' degree_awarded: PhD department: - _id: GradSch - _id: JoDa doi: 10.15479/at:ista:12470 ec_funded: 1 file: - access_level: open_access checksum: 1a2306e5f59f52df598e7ecfadf921ac content_type: application/pdf creator: cchlebak date_created: 2023-01-31T15:11:42Z date_updated: 2023-07-27T22:30:54Z embargo: 2023-07-09 file_id: '12471' file_name: 20230109_PhD_thesis_JM_final.pdf file_size: 41771714 relation: main_file - access_level: closed checksum: 0bebbdee0773443959e1f6ab8caf281f content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document creator: cchlebak date_created: 2023-01-31T15:11:51Z date_updated: 2023-07-10T22:30:04Z embargo_to: open_access file_id: '12472' file_name: 20230109_PhD_thesis_JM_final.docx file_size: 66983464 relation: source_file file_date_updated: 2023-07-27T22:30:54Z has_accepted_license: '1' language: - iso: eng month: '01' oa: 1 oa_version: Published Version page: '201' project: - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program - _id: 26AA4EF2-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: W1232-B24 name: Molecular Drug Targets publication_identifier: isbn: - ' 978-3-99078-026-8' issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '11943' relation: part_of_dissertation status: public - id: '11950' relation: part_of_dissertation status: public status: public supervisor: - first_name: Johann G full_name: Danzl, Johann G id: 42EFD3B6-F248-11E8-B48F-1D18A9856A87 last_name: Danzl orcid: 0000-0001-8559-3973 title: A versatile toolbox for the comprehensive analysis of nervous tissue organization with light microscopy tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2023' ... --- _id: '14510' acknowledged_ssus: - _id: EM-Fac - _id: Bio - _id: LifeSc alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Nataliia full_name: Gnyliukh, Nataliia id: 390C1120-F248-11E8-B48F-1D18A9856A87 last_name: Gnyliukh orcid: 0000-0002-2198-0509 citation: ama: Gnyliukh N. Mechanism of clathrin-coated vesicle  formation during endocytosis in plants. 2023. doi:10.15479/at:ista:14510 apa: Gnyliukh, N. (2023). Mechanism of clathrin-coated vesicle  formation during endocytosis in plants. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:14510 chicago: Gnyliukh, Nataliia. “Mechanism of Clathrin-Coated Vesicle  Formation during Endocytosis in Plants.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:14510. ieee: N. Gnyliukh, “Mechanism of clathrin-coated vesicle  formation during endocytosis in plants,” Institute of Science and Technology Austria, 2023. ista: Gnyliukh N. 2023. Mechanism of clathrin-coated vesicle  formation during endocytosis in plants. Institute of Science and Technology Austria. mla: Gnyliukh, Nataliia. Mechanism of Clathrin-Coated Vesicle  Formation during Endocytosis in Plants. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:14510. short: N. Gnyliukh, Mechanism of Clathrin-Coated Vesicle  Formation during Endocytosis in Plants, Institute of Science and Technology Austria, 2023. date_created: 2023-11-10T09:10:06Z date_published: 2023-11-10T00:00:00Z date_updated: 2024-03-27T23:30:45Z day: '10' ddc: - '570' degree_awarded: PhD department: - _id: GradSch - _id: JiFr - _id: MaLo doi: 10.15479/at:ista:14510 ec_funded: 1 file: - access_level: closed checksum: 3d5e680bfc61f98e308c434f45cc9bd6 content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document creator: ngnyliuk date_created: 2023-11-20T09:18:51Z date_updated: 2023-11-20T09:18:51Z file_id: '14567' file_name: Thesis_Gnyliukh_final_08_11_23.docx file_size: 20824903 relation: source_file - access_level: closed checksum: bfc96d47fc4e7e857dd71656097214a4 content_type: application/pdf creator: ngnyliuk date_created: 2023-11-20T09:23:11Z date_updated: 2023-11-23T13:10:55Z embargo: 2024-11-23 embargo_to: open_access file_id: '14568' file_name: Thesis_Gnyliukh_final_20_11_23.pdf file_size: 24871844 relation: main_file file_date_updated: 2023-11-23T13:10:55Z has_accepted_license: '1' keyword: - Clathrin-Mediated Endocytosis - vesicle scission - Dynamin-Related Protein 2 - SH3P2 - TPLATE complex - Total internal reflection fluorescence microscopy - Arabidopsis thaliana language: - iso: eng month: '11' oa_version: Published Version page: '180' project: - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program publication_identifier: isbn: - 978-3-99078-037-4 issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '14591' relation: part_of_dissertation status: public - id: '9887' relation: part_of_dissertation status: public - id: '8139' relation: part_of_dissertation status: public status: public supervisor: - first_name: Jiří full_name: Friml, Jiří id: 4159519E-F248-11E8-B48F-1D18A9856A87 last_name: Friml orcid: 0000-0002-8302-7596 - first_name: Martin full_name: Loose, Martin id: 462D4284-F248-11E8-B48F-1D18A9856A87 last_name: Loose orcid: 0000-0001-7309-9724 title: Mechanism of clathrin-coated vesicle formation during endocytosis in plants tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2023' ... --- _id: '12897' abstract: - lang: eng text: "Inverse design problems in fabrication-aware shape optimization are typically solved on discrete representations such as polygonal meshes. This thesis argues that there are benefits to treating these problems in the same domain as human designers, namely, the parametric one. One reason is that discretizing a parametric model usually removes the capability of making further manual changes to the design, because the human intent is captured by the shape parameters. Beyond this, knowledge about a design problem can sometimes reveal a structure that is present in a smooth representation, but is fundamentally altered by discretizing. In this case, working in the parametric domain may even simplify the optimization task. We present two lines of research that explore both of these aspects of fabrication-aware shape optimization on parametric representations.\r\n\r\nThe first project studies the design of plane elastic curves and Kirchhoff rods, which are common mathematical models for describing the deformation of thin elastic rods such as beams, ribbons, cables, and hair. Our main contribution is a characterization of all curved shapes that can be attained by bending and twisting elastic rods having a stiffness that is allowed to vary across the length. Elements like these can be manufactured using digital fabrication devices such as 3d printers and digital cutters, and have applications in free-form architecture and soft robotics.\r\n\r\nWe show that the family of curved shapes that can be produced this way admits geometric description that is concise and computationally convenient. In the case of plane curves, the geometric description is intuitive enough to allow a designer to determine whether a curved shape is physically achievable by visual inspection alone. We also present shape optimization algorithms that convert a user-defined curve in the plane or in three dimensions into the geometry of an elastic rod that will naturally deform to follow this curve when its endpoints are attached to a support structure. Implemented in an interactive software design tool, the rod geometry is generated in real time as the user edits a curve and enables fast prototyping. \r\n\r\nThe second project tackles the problem of general-purpose shape optimization on CAD models using a novel variant of the extended finite element method (XFEM). Our goal is the decoupling between the simulation mesh and the CAD model, so no geometry-dependent meshing or remeshing needs to be performed when the CAD parameters change during optimization. This is achieved by discretizing the embedding space of the CAD model, and using a new high-accuracy numerical integration method to enable XFEM on free-form elements bounded by the parametric surface patches of the model. Our simulation is differentiable from the CAD parameters to the simulation output, which enables us to use off-the-shelf gradient-based optimization procedures. The result is a method that fits seamlessly into the CAD workflow because it works on the same representation as the designer, enabling the alternation of manual editing and fabrication-aware optimization at will." acknowledged_ssus: - _id: M-Shop alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Christian full_name: Hafner, Christian id: 400429CC-F248-11E8-B48F-1D18A9856A87 last_name: Hafner citation: ama: 'Hafner C. Inverse shape design with parametric representations: Kirchhoff Rods and parametric surface models. 2023. doi:10.15479/at:ista:12897' apa: 'Hafner, C. (2023). Inverse shape design with parametric representations: Kirchhoff Rods and parametric surface models. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12897' chicago: 'Hafner, Christian. “Inverse Shape Design with Parametric Representations: Kirchhoff Rods and Parametric Surface Models.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:12897.' ieee: 'C. Hafner, “Inverse shape design with parametric representations: Kirchhoff Rods and parametric surface models,” Institute of Science and Technology Austria, 2023.' ista: 'Hafner C. 2023. Inverse shape design with parametric representations: Kirchhoff Rods and parametric surface models. Institute of Science and Technology Austria.' mla: 'Hafner, Christian. Inverse Shape Design with Parametric Representations: Kirchhoff Rods and Parametric Surface Models. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:12897.' short: 'C. Hafner, Inverse Shape Design with Parametric Representations: Kirchhoff Rods and Parametric Surface Models, Institute of Science and Technology Austria, 2023.' date_created: 2023-05-05T10:40:14Z date_published: 2023-05-05T00:00:00Z date_updated: 2024-01-29T10:47:51Z day: '05' ddc: - '516' - '004' - '518' - '531' degree_awarded: PhD department: - _id: GradSch - _id: BeBi doi: 10.15479/at:ista:12897 ec_funded: 1 file: - access_level: open_access checksum: cc2094e92fa27000b70eb4bfb76d6b5a content_type: application/pdf creator: chafner date_created: 2023-05-11T10:43:20Z date_updated: 2023-12-08T23:30:04Z embargo: 2023-12-07 file_id: '12942' file_name: thesis-hafner-2023may11-a2b.pdf file_size: 50714445 relation: main_file - access_level: closed checksum: a6b51334be2b81672357b1549afab40c content_type: application/pdf creator: chafner date_created: 2023-05-11T10:43:44Z date_updated: 2023-12-08T23:30:04Z embargo_to: open_access file_id: '12943' file_name: thesis-release-form.pdf file_size: 265319 relation: source_file file_date_updated: 2023-12-08T23:30:04Z has_accepted_license: '1' language: - iso: eng month: '05' oa: 1 oa_version: Published Version page: '180' project: - _id: 24F9549A-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '715767' name: 'MATERIALIZABLE: Intelligent fabrication-oriented Computational Design and Modeling' publication_identifier: isbn: - 978-3-99078-031-2 issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '9817' relation: part_of_dissertation status: public - id: '7117' relation: part_of_dissertation status: public - id: '13188' relation: dissertation_contains status: public status: public supervisor: - first_name: Bernd full_name: Bickel, Bernd id: 49876194-F248-11E8-B48F-1D18A9856A87 last_name: Bickel orcid: 0000-0001-6511-9385 title: 'Inverse shape design with parametric representations: Kirchhoff Rods and parametric surface models' type: dissertation user_id: 400429CC-F248-11E8-B48F-1D18A9856A87 year: '2023' ... --- _id: '12072' abstract: - lang: eng text: "In this thesis, we study two of the most important questions in Arithmetic geometry: that of the existence and density of solutions to Diophantine equations. In order for a Diophantine equation to have any solutions over the rational numbers, it must have solutions everywhere locally, i.e., over R and over Qp for every prime p. The converse, called the Hasse principle, is known to fail in general. However, it is still a central question in Arithmetic geometry to determine for which varieties the Hasse principle does hold. In this work, we establish the Hasse principle for a wide new family of varieties of the form f(t) = NK/Q(x) ̸= 0, where f is a polynomial with integer coefficients and NK/Q denotes the norm\r\nform associated to a number field K. Our results cover products of arbitrarily many linear, quadratic or cubic factors, and generalise an argument of Irving [69], which makes use of the beta sieve of Rosser and Iwaniec. We also demonstrate how our main sieve results can be applied to treat new cases of a conjecture of Harpaz and Wittenberg on locally split values of polynomials over number fields, and discuss consequences for rational points in fibrations.\r\nIn the second question, about the density of solutions, one defines a height function and seeks to estimate asymptotically the number of points of height bounded by B as B → ∞. Traditionally, one either counts rational points, or\r\nintegral points with respect to a suitable model. However, in this thesis, we study an emerging area of interest in Arithmetic geometry known as Campana points, which in some sense interpolate between rational and integral points.\r\nMore precisely, we count the number of nonzero integers z1, z2, z3 such that gcd(z1, z2, z3) = 1, and z1, z2, z3, z1 + z2 + z3 are all squareful and bounded by B. Using the circle method, we obtain an asymptotic formula which agrees in\r\nthe power of B and log B with a bold new generalisation of Manin’s conjecture to the setting of Campana points, recently formulated by Pieropan, Smeets, Tanimoto and Várilly-Alvarado [96]. However, in this thesis we also provide the first known counterexamples to leading constant predicted by their conjecture. " acknowledgement: I acknowledge the received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska Curie Grant Agreement No. 665385. alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Alec L full_name: Shute, Alec L id: 440EB050-F248-11E8-B48F-1D18A9856A87 last_name: Shute orcid: 0000-0002-1812-2810 citation: ama: 'Shute AL. Existence and density problems in Diophantine geometry: From norm forms to Campana points. 2022. doi:10.15479/at:ista:12072' apa: 'Shute, A. L. (2022). Existence and density problems in Diophantine geometry: From norm forms to Campana points. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12072' chicago: 'Shute, Alec L. “Existence and Density Problems in Diophantine Geometry: From Norm Forms to Campana Points.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:12072.' ieee: 'A. L. Shute, “Existence and density problems in Diophantine geometry: From norm forms to Campana points,” Institute of Science and Technology Austria, 2022.' ista: 'Shute AL. 2022. Existence and density problems in Diophantine geometry: From norm forms to Campana points. Institute of Science and Technology Austria.' mla: 'Shute, Alec L. Existence and Density Problems in Diophantine Geometry: From Norm Forms to Campana Points. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:12072.' short: 'A.L. Shute, Existence and Density Problems in Diophantine Geometry: From Norm Forms to Campana Points, Institute of Science and Technology Austria, 2022.' date_created: 2022-09-08T21:53:03Z date_published: 2022-09-08T00:00:00Z date_updated: 2023-02-21T16:37:35Z day: '08' ddc: - '512' degree_awarded: PhD department: - _id: GradSch - _id: TiBr doi: 10.15479/at:ista:12072 ec_funded: 1 file: - access_level: open_access checksum: bf073344320e05d92c224786cec2e92d content_type: application/pdf creator: ashute date_created: 2022-09-08T21:50:34Z date_updated: 2022-09-08T21:50:34Z file_id: '12073' file_name: Thesis_final_draft.pdf file_size: 1907386 relation: main_file success: 1 - access_level: closed checksum: b054ac6baa09f70e8235403a4abbed80 content_type: application/octet-stream creator: ashute date_created: 2022-09-08T21:50:42Z date_updated: 2022-09-12T11:24:21Z file_id: '12074' file_name: athesis.tex file_size: 495393 relation: source_file - access_level: closed checksum: 0a31e905f1cff5eb8110978cc90e1e79 content_type: application/x-zip-compressed creator: ashute date_created: 2022-09-09T12:05:00Z date_updated: 2022-09-12T11:24:21Z file_id: '12078' file_name: qfcjsfmtvtbfrjjvhdzrnqxfvgjvxtbf.zip file_size: 944534 relation: source_file file_date_updated: 2022-09-12T11:24:21Z has_accepted_license: '1' language: - iso: eng month: '09' oa: 1 oa_version: Published Version page: '208' project: - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program publication_identifier: isbn: - 978-3-99078-023-7 issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '12076' relation: part_of_dissertation status: public - id: '12077' relation: part_of_dissertation status: public status: public supervisor: - first_name: Timothy D full_name: Browning, Timothy D id: 35827D50-F248-11E8-B48F-1D18A9856A87 last_name: Browning orcid: 0000-0002-8314-0177 title: 'Existence and density problems in Diophantine geometry: From norm forms to Campana points' tmp: image: /images/cc_by_nc_sa.png legal_code_url: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode name: Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) short: CC BY-NC-SA (4.0) type: dissertation user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2022' ... --- _id: '11777' abstract: - lang: eng text: "In this dissertation we study coboundary expansion of simplicial complex with a view of giving geometric applications.\r\nOur main novel tool is an equivariant version of Gromov's celebrated Topological Overlap Theorem. The equivariant topological overlap theorem leads to various geometric applications including a quantitative non-embeddability result for sufficiently thick buildings (which partially resolves a conjecture of Tancer and Vorwerk) and an improved lower bound on the pair-crossing number of (bounded degree) expander graphs. Additionally, we will give new proofs for several known lower bounds for geometric problems such as the number of Tverberg partitions or the crossing number of complete bipartite graphs.\r\nFor the aforementioned applications one is naturally lead to study expansion properties of joins of simplicial complexes. In the presence of a special certificate for expansion (as it is the case, e.g., for spherical buildings), the join of two expanders is an expander. On the flip-side, we report quite some evidence that coboundary expansion exhibits very non-product-like behaviour under taking joins. For instance, we exhibit infinite families of graphs $(G_n)_{n\\in \\mathbb{N}}$ and $(H_n)_{n\\in\\mathbb{N}}$ whose join $G_n*H_n$ has expansion of lower order than the product of the expansion constant of the graphs. Moreover, we show an upper bound of $(d+1)/2^d$ on the normalized coboundary expansion constants for the complete multipartite complex $[n]^{*(d+1)}$ (under a mild divisibility condition on $n$).\r\nVia the probabilistic method the latter result extends to an upper bound of $(d+1)/2^d+\\varepsilon$ on the coboundary expansion constant of the spherical building associated with $\\mathrm{PGL}_{d+2}(\\mathbb{F}_q)$ for any $\\varepsilon>0$ and sufficiently large $q=q(\\varepsilon)$. This disproves a conjecture of Lubotzky, Meshulam and Mozes -- in a rather strong sense.\r\nBy improving on existing lower bounds we make further progress towards closing the gap between the known lower and upper bounds on the coboundary expansion constants of $[n]^{*(d+1)}$. The best improvements we achieve using computer-aided proofs and flag algebras. The exact value even for the complete $3$-partite $2$-dimensional complex $[n]^{*3}$ remains unknown but we are happy to conjecture a precise value for every $n$. %Moreover, we show that a previously shown lower bound on the expansion constant of the spherical building associated with $\\mathrm{PGL}_{2}(\\mathbb{F}_q)$ is not tight.\r\nIn a loosely structured, last chapter of this thesis we collect further smaller observations related to expansion. We point out a link between discrete Morse theory and a technique for showing coboundary expansion, elaborate a bit on the hardness of computing coboundary expansion constants, propose a new criterion for coboundary expansion (in a very dense setting) and give one way of making the folklore result that expansion of links is a necessary condition for a simplicial complex to be an expander precise." alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Pascal full_name: Wild, Pascal id: 4C20D868-F248-11E8-B48F-1D18A9856A87 last_name: Wild citation: ama: Wild P. High-dimensional expansion and crossing numbers of simplicial complexes. 2022. doi:10.15479/at:ista:11777 apa: Wild, P. (2022). High-dimensional expansion and crossing numbers of simplicial complexes. Institute of Science and Technology. https://doi.org/10.15479/at:ista:11777 chicago: Wild, Pascal. “High-Dimensional Expansion and Crossing Numbers of Simplicial Complexes.” Institute of Science and Technology, 2022. https://doi.org/10.15479/at:ista:11777. ieee: P. Wild, “High-dimensional expansion and crossing numbers of simplicial complexes,” Institute of Science and Technology, 2022. ista: Wild P. 2022. High-dimensional expansion and crossing numbers of simplicial complexes. Institute of Science and Technology. mla: Wild, Pascal. High-Dimensional Expansion and Crossing Numbers of Simplicial Complexes. Institute of Science and Technology, 2022, doi:10.15479/at:ista:11777. short: P. Wild, High-Dimensional Expansion and Crossing Numbers of Simplicial Complexes, Institute of Science and Technology, 2022. date_created: 2022-08-10T15:51:19Z date_published: 2022-08-11T00:00:00Z date_updated: 2023-06-22T09:56:36Z day: '11' ddc: - '500' - '516' - '514' degree_awarded: PhD department: - _id: GradSch - _id: UlWa doi: 10.15479/at:ista:11777 ec_funded: 1 file: - access_level: open_access checksum: f5f3af1fb7c8a24b71ddc88ad7f7c5b4 content_type: text/x-python creator: pwild date_created: 2022-08-10T15:34:04Z date_updated: 2022-08-10T15:34:04Z description: Code for computer-assisted proofs in Section 8.4.7 in Thesis file_id: '11780' file_name: flags.py file_size: 16828 relation: supplementary_material - access_level: open_access checksum: 1f7c12dfe3bdaa9b147e4fbc3d34e3d5 content_type: text/x-c++src creator: pwild date_created: 2022-08-10T15:34:10Z date_updated: 2022-08-10T15:34:10Z description: Code for proof of Lemma 8.20 in Thesis file_id: '11781' file_name: lowerbound.cpp file_size: 12226 relation: supplementary_material - access_level: open_access checksum: 4cf81455c49e5dec3b9b2e3980137eeb content_type: text/x-python creator: pwild date_created: 2022-08-10T15:34:17Z date_updated: 2022-08-10T15:34:17Z description: Code for proof of Proposition 7.9 in Thesis file_id: '11782' file_name: upperbound.py file_size: 3240 relation: supplementary_material - access_level: open_access checksum: 4e96575b10cbe4e0d0db2045b2847774 content_type: application/pdf creator: pwild date_created: 2022-08-11T16:08:33Z date_updated: 2022-08-11T16:08:33Z file_id: '11809' file_name: finalthesisPascalWildPDFA.pdf file_size: 5086282 relation: main_file title: High-Dimensional Expansion and Crossing Numbers of Simplicial Complexes - access_level: closed checksum: 92d94842a1fb6dca5808448137573b2e content_type: application/zip creator: pwild date_created: 2022-08-11T16:09:19Z date_updated: 2022-08-11T16:09:19Z file_id: '11810' file_name: ThesisSubmission.zip file_size: 18150068 relation: source_file file_date_updated: 2022-08-11T16:09:19Z has_accepted_license: '1' language: - iso: eng month: '08' oa: 1 oa_version: Published Version page: '170' project: - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program publication_identifier: isbn: - 978-3-99078-021-3 issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology status: public supervisor: - first_name: Uli full_name: Wagner, Uli id: 36690CA2-F248-11E8-B48F-1D18A9856A87 last_name: Wagner orcid: 0000-0002-1494-0568 title: High-dimensional expansion and crossing numbers of simplicial complexes type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2022' ... --- _id: '11128' abstract: - lang: eng text: "Although we often see studies focusing on simple or even discrete traits in studies of colouration,\r\nthe variation of “appearance” phenotypes found in nature is often more complex, continuous\r\nand high-dimensional. Therefore, we developed automated methods suitable for large datasets\r\nof genomes and images, striving to account for their complex nature, while minimising human\r\nbias. We used these methods on a dataset of more than 20, 000 plant SNP genomes and\r\ncorresponding fower images from a hybrid zone of two subspecies of Antirrhinum majus with\r\ndistinctly coloured fowers to improve our understanding of the genetic nature of the fower\r\ncolour in our study system.\r\nFirstly, we use the advantage of large numbers of genotyped plants to estimate the haplotypes in\r\nthe main fower colour regulating region. We study colour- and geography-related characteristics\r\nof the estimated haplotypes and how they connect to their relatedness. We show discrepancies\r\nfrom the expected fower colour distributions given the genotype and identify particular\r\nhaplotypes leading to unexpected phenotypes. We also confrm a signifcant defcit of the\r\ndouble recessive recombinant and quite surprisingly, we show that haplotypes of the most\r\nfrequent parental type are much less variable than others.\r\nSecondly, we introduce our pipeline capable of processing tens of thousands of full fower\r\nimages without human interaction and summarising each image into a set of informative scores.\r\nWe show the compatibility of these machine-measured fower colour scores with the previously\r\nused manual scores and study impact of external efect on the resulting scores. Finally, we use\r\nthe machine-measured fower colour scores to ft and examine a phenotype cline across the\r\nhybrid zone in Planoles using full fower images as opposed to discrete, manual scores and\r\ncompare it with the genotypic cline." acknowledged_ssus: - _id: ScienComp - _id: Bio alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Lenka full_name: Matejovicova, Lenka id: 2DFDEC72-F248-11E8-B48F-1D18A9856A87 last_name: Matejovicova citation: ama: Matejovicova L. Genetic basis of flower colour as a model for adaptive evolution. 2022. doi:10.15479/at:ista:11128 apa: Matejovicova, L. (2022). Genetic basis of flower colour as a model for adaptive evolution. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:11128 chicago: Matejovicova, Lenka. “Genetic Basis of Flower Colour as a Model for Adaptive Evolution.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:11128. ieee: L. Matejovicova, “Genetic basis of flower colour as a model for adaptive evolution,” Institute of Science and Technology Austria, 2022. ista: Matejovicova L. 2022. Genetic basis of flower colour as a model for adaptive evolution. Institute of Science and Technology Austria. mla: Matejovicova, Lenka. Genetic Basis of Flower Colour as a Model for Adaptive Evolution. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:11128. short: L. Matejovicova, Genetic Basis of Flower Colour as a Model for Adaptive Evolution, Institute of Science and Technology Austria, 2022. date_created: 2022-04-07T08:19:54Z date_published: 2022-04-06T00:00:00Z date_updated: 2023-06-23T06:26:41Z day: '06' ddc: - '576' - '582' degree_awarded: PhD department: - _id: GradSch - _id: NiBa doi: 10.15479/at:ista:11128 file: - access_level: open_access checksum: e9609bc4e8f8e20146fc1125fd4f1bf7 content_type: application/pdf creator: cchlebak date_created: 2022-04-07T08:11:34Z date_updated: 2022-04-07T08:11:34Z file_id: '11129' file_name: LenkaPhD_Official_PDFA.pdf file_size: 11906472 relation: main_file - access_level: closed checksum: 99d67040432fd07a225643a212ee8588 content_type: application/x-zip-compressed creator: cchlebak date_created: 2022-04-07T08:11:51Z date_updated: 2022-04-07T08:11:51Z file_id: '11130' file_name: LenkaPhD Official_source.zip file_size: 23036766 relation: source_file file_date_updated: 2022-04-07T08:11:51Z has_accepted_license: '1' language: - iso: eng month: '04' oa: 1 oa_version: Published Version page: '112' publication_identifier: isbn: - 978-3-99078-016-9 issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria status: public supervisor: - first_name: Nicholas H full_name: Barton, Nicholas H id: 4880FE40-F248-11E8-B48F-1D18A9856A87 last_name: Barton orcid: 0000-0002-8548-5240 title: Genetic basis of flower colour as a model for adaptive evolution tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2022' ... --- _id: '11945' abstract: - lang: eng text: "G protein-coupled receptors (GPCRs) respond to specific ligands and regulate multiple processes ranging from cell growth and immune responses to neuronal signal transmission. However, ligands for many GPCRs remain unknown, suffer from off-target effects or have poor bioavailability. Additional challenges exist to dissect cell-type specific responses when the same GPCR is expressed on several cell types within the body. Here, we overcome these limitations by engineering DREADD-based GPCR chimeras that selectively bind their agonist clozapine-N-oxide (CNO) and mimic a GPCR-of-interest in a desired cell type.\r\nWe validated our approach with β2-adrenergic receptor (β2AR/ADRB2) and show that our chimeric DREADD-β2AR triggers comparable responses on second messenger and kinase activity, post-translational modifications, and protein-protein interactions. Since β2AR is also enriched in microglia, which can drive inflammation in the central nervous system, we expressed chimeric DREADD-β2AR in primary microglia and successfully recapitulate β2AR-mediated filopodia formation through CNO stimulation. To dissect the role of selected GPCRs during microglial inflammation, we additionally generated DREADD-based chimeras for microglia-enriched GPR65 and GPR109A/HCAR2. In a microglia cell line, DREADD-β2AR and DREADD-GPR65 both modulated the inflammatory response with a similar profile as endogenously expressed β2AR, while DREADD-GPR109A showed no impact.\r\nOur DREADD-based approach provides the means to obtain mechanistic and functional insights into GPCR signaling on a cell-type specific level." acknowledged_ssus: - _id: Bio - _id: PreCl - _id: LifeSc alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Rouven full_name: Schulz, Rouven id: 4C5E7B96-F248-11E8-B48F-1D18A9856A87 last_name: Schulz orcid: 0000-0001-5297-733X citation: ama: Schulz R. Chimeric G protein-coupled receptors mimic distinct signaling pathways and modulate microglia function. 2022. doi:10.15479/at:ista:11945 apa: Schulz, R. (2022). Chimeric G protein-coupled receptors mimic distinct signaling pathways and modulate microglia function. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:11945 chicago: Schulz, Rouven. “Chimeric G Protein-Coupled Receptors Mimic Distinct Signaling Pathways and Modulate Microglia Function.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:11945. ieee: R. Schulz, “Chimeric G protein-coupled receptors mimic distinct signaling pathways and modulate microglia function,” Institute of Science and Technology Austria, 2022. ista: Schulz R. 2022. Chimeric G protein-coupled receptors mimic distinct signaling pathways and modulate microglia function. Institute of Science and Technology Austria. mla: Schulz, Rouven. Chimeric G Protein-Coupled Receptors Mimic Distinct Signaling Pathways and Modulate Microglia Function. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:11945. short: R. Schulz, Chimeric G Protein-Coupled Receptors Mimic Distinct Signaling Pathways and Modulate Microglia Function, Institute of Science and Technology Austria, 2022. date_created: 2022-08-23T11:33:11Z date_published: 2022-08-23T00:00:00Z date_updated: 2023-08-03T13:02:26Z day: '23' ddc: - '570' degree_awarded: PhD department: - _id: GradSch - _id: SaSi doi: 10.15479/at:ista:11945 file: - access_level: open_access checksum: 61b1b666a210ff7cdd0e95ea75207a13 content_type: application/pdf creator: rschulz date_created: 2022-08-25T08:59:57Z date_updated: 2022-08-25T08:59:57Z file_id: '11970' file_name: Thesis_Rouven_Schulz_2022_final.pdf file_size: 28079331 relation: main_file success: 1 - access_level: closed checksum: 2b8f95ea1c134dbdb927b41b1dbeeeb5 content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document creator: rschulz date_created: 2022-08-25T09:00:11Z date_updated: 2022-08-25T09:33:31Z file_id: '11971' file_name: Thesis_Rouven_Schulz_2022_final.docx file_size: 27226963 relation: source_file file_date_updated: 2022-08-25T09:33:31Z has_accepted_license: '1' language: - iso: eng month: '08' oa: 1 oa_version: Published Version page: '133' project: - _id: 267F75D8-B435-11E9-9278-68D0E5697425 name: Modulating microglia through G protein-coupled receptor (GPCR) signaling publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '11995' relation: dissertation_contains status: public status: public supervisor: - first_name: Sandra full_name: Siegert, Sandra id: 36ACD32E-F248-11E8-B48F-1D18A9856A87 last_name: Siegert orcid: 0000-0001-8635-0877 title: Chimeric G protein-coupled receptors mimic distinct signaling pathways and modulate microglia function tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2022' ... --- _id: '12390' abstract: - lang: eng text: "The scope of this thesis is to study quantum systems exhibiting a continuous symmetry that\r\nis broken on the level of the corresponding effective theory. In particular we are going to\r\ninvestigate translation-invariant Bose gases in the mean field limit, effectively described by\r\nthe Hartree functional, and the Fröhlich Polaron in the regime of strong coupling, effectively\r\ndescribed by the Pekar functional. The latter is a model describing the interaction between a\r\ncharged particle and the optical modes of a polar crystal. Regarding the former, we assume in\r\naddition that the particles in the gas are unconfined, and typically we will consider particles\r\nthat are subject to an attractive interaction. In both cases the ground state energy of the\r\nHamiltonian is not a proper eigenvalue due to the underlying translation-invariance, while on\r\nthe contrary there exists a whole invariant orbit of minimizers for the corresponding effective\r\nfunctionals. Both, the absence of proper eigenstates and the broken symmetry of the effective\r\ntheory, make the study significantly more involved and it is the content of this thesis to\r\ndevelop a frameworks which allows for a systematic way to circumvent these issues.\r\nIt is a well-established result that the ground state energy of Bose gases in the mean field limit,\r\nas well as the ground state energy of the Fröhlich Polaron in the regime of strong coupling, is\r\nto leading order given by the minimal energy of the corresponding effective theory. As part\r\nof this thesis we identify the sub-leading term in the expansion of the ground state energy,\r\nwhich can be interpreted as the quantum correction to the classical energy, since the effective\r\ntheories under consideration can be seen as classical counterparts.\r\nWe are further going to establish an asymptotic expression for the energy-momentum relation\r\nof the Fröhlich Polaron in the strong coupling limit. In the regime of suitably small momenta,\r\nthis asymptotic expression agrees with the energy-momentum relation of a free particle having\r\nan effectively increased mass, and we find that this effectively increased mass agrees with the\r\nconjectured value in the physics literature.\r\nIn addition we will discuss two unrelated papers written by the author during his stay at ISTA\r\nin the appendix. The first one concerns the realization of anyons, which are quasi-particles\r\nacquiring a non-trivial phase under the exchange of two particles, as molecular impurities.\r\nThe second one provides a classification of those vector fields defined on a given manifold\r\nthat can be written as the gradient of a given functional with respect to a suitable metric,\r\nprovided that some mild smoothness assumptions hold. This classification is subsequently\r\nused to identify those quantum Markov semigroups that can be written as a gradient flow of\r\nthe relative entropy.\r\n" alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Morris full_name: Brooks, Morris id: B7ECF9FC-AA38-11E9-AC9A-0930E6697425 last_name: Brooks orcid: 0000-0002-6249-0928 citation: ama: Brooks M. Translation-invariant quantum systems with effectively broken symmetry. 2022. doi:10.15479/at:ista:12390 apa: Brooks, M. (2022). Translation-invariant quantum systems with effectively broken symmetry. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12390 chicago: Brooks, Morris. “Translation-Invariant Quantum Systems with Effectively Broken Symmetry.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:12390. ieee: M. Brooks, “Translation-invariant quantum systems with effectively broken symmetry,” Institute of Science and Technology Austria, 2022. ista: Brooks M. 2022. Translation-invariant quantum systems with effectively broken symmetry. Institute of Science and Technology Austria. mla: Brooks, Morris. Translation-Invariant Quantum Systems with Effectively Broken Symmetry. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:12390. short: M. Brooks, Translation-Invariant Quantum Systems with Effectively Broken Symmetry, Institute of Science and Technology Austria, 2022. date_created: 2023-01-26T10:00:42Z date_published: 2022-12-15T00:00:00Z date_updated: 2023-08-07T13:32:09Z day: '15' ddc: - '500' degree_awarded: PhD department: - _id: GradSch - _id: RoSe doi: 10.15479/at:ista:12390 ec_funded: 1 file: - access_level: open_access checksum: b31460e937f33b557abb40ebef02b567 content_type: application/pdf creator: cchlebak date_created: 2023-01-26T10:02:34Z date_updated: 2023-01-26T10:02:34Z file_id: '12391' file_name: Brooks_Thesis.pdf file_size: 3095225 relation: main_file success: 1 - access_level: closed checksum: 9751869fa5e7981588ad4228f4fd4bd6 content_type: application/octet-stream creator: cchlebak date_created: 2023-01-26T10:02:42Z date_updated: 2023-01-26T10:02:42Z file_id: '12392' file_name: Brooks_Thesis.tex file_size: 809842 relation: source_file file_date_updated: 2023-01-26T10:02:42Z has_accepted_license: '1' language: - iso: eng month: '12' oa: 1 oa_version: Published Version page: '196' project: - _id: 25C6DC12-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '694227' name: Analysis of quantum many-body systems publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '9005' relation: part_of_dissertation status: public status: public supervisor: - first_name: Robert full_name: Seiringer, Robert id: 4AFD0470-F248-11E8-B48F-1D18A9856A87 last_name: Seiringer orcid: 0000-0002-6781-0521 title: Translation-invariant quantum systems with effectively broken symmetry tmp: image: /images/cc_by_nc_sa.png legal_code_url: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode name: Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) short: CC BY-NC-SA (4.0) type: dissertation user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2022' ... --- _id: '12368' abstract: - lang: eng text: "Metazoan development relies on the formation and remodeling of cell-cell contacts. The \r\nbinding of adhesion receptors and remodeling of the actomyosin cell cortex at cell-cell \r\ninteraction sites have been implicated in cell-cell contact formation. Yet, how these two \r\nprocesses functionally interact to drive cell-cell contact expansion and strengthening \r\nremains unclear. Here, we study how primary germ layer progenitor cells from zebrafish \r\nbind to supported lipid bilayers (SLB) functionalized with E-cadherin ectodomains as an \r\nassay system for monitoring cell-cell contact formation at high spatiotemporal resolution. \r\nWe show that cell-cell contact formation represents a two-tiered process: E-cadherin\x02mediated downregulation of the small GTPase RhoA at the forming contact leads to both \r\ndepletion of Myosin-2 and decrease of F-actin. This is followed by centrifugal actin \r\nnetwork flows at the contact triggered by a sharp gradient of Myosin-2 at the rim of the \r\ncontact zone, with Myosin-2 displaying higher cortical localization outside than inside of \r\nthe contact. These centrifugal cortical actin flows, in turn, not only further dilute the actin \r\nnetwork at the contact disc, but also lead to an accumulation of both F-actin and E\x02cadherin at the contact rim. Eventually, this combination of actomyosin downregulation \r\nand flows at the contact contribute to the characteristic molecular organization implicated \r\nin contact formation and maintenance: depletion of cortical actomyosin at the contact disc, \r\ndriving contact expansion by lowering interfacial tension at the contact, and accumulation \r\nof both E-cadherin and F-actin at the contact rim, mechanically linking the contractile \r\ncortices of the adhering cells. Thus, using a biomimetic assay, we exemplify how \r\nadhesion signaling and cell mechanics function together to modulate the spatial \r\norganization of cell-cell contacts." acknowledged_ssus: - _id: LifeSc - _id: Bio - _id: NanoFab alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Feyza N full_name: Arslan, Feyza N id: 49DA7910-F248-11E8-B48F-1D18A9856A87 last_name: Arslan orcid: 0000-0001-5809-9566 citation: ama: Arslan FN. Remodeling of E-cadherin-mediated contacts via cortical  flows. 2022. doi:10.15479/at:ista:12153 apa: Arslan, F. N. (2022). Remodeling of E-cadherin-mediated contacts via cortical  flows. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12153 chicago: Arslan, Feyza N. “Remodeling of E-Cadherin-Mediated Contacts via Cortical  Flows.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:12153. ieee: F. N. Arslan, “Remodeling of E-cadherin-mediated contacts via cortical  flows,” Institute of Science and Technology Austria, 2022. ista: Arslan FN. 2022. Remodeling of E-cadherin-mediated contacts via cortical  flows. Institute of Science and Technology Austria. mla: Arslan, Feyza N. Remodeling of E-Cadherin-Mediated Contacts via Cortical  Flows. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:12153. short: F.N. Arslan, Remodeling of E-Cadherin-Mediated Contacts via Cortical  Flows, Institute of Science and Technology Austria, 2022. date_created: 2023-01-25T10:43:24Z date_published: 2022-09-29T00:00:00Z date_updated: 2023-08-08T13:14:10Z day: '29' ddc: - '570' degree_awarded: PhD department: - _id: GradSch - _id: CaHe doi: 10.15479/at:ista:12153 ec_funded: 1 file: - access_level: open_access checksum: e54a3e69b83ebf166544164afd25608e content_type: application/pdf creator: cchlebak date_created: 2023-01-25T10:52:46Z date_updated: 2023-01-25T10:52:46Z file_id: '12369' file_name: THESIS_FINAL_FArslan_pdfa.pdf file_size: 14581024 relation: main_file success: 1 file_date_updated: 2023-01-25T10:52:46Z has_accepted_license: '1' language: - iso: eng month: '09' oa: 1 oa_version: Published Version page: '113' project: - _id: 260F1432-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '742573' name: Interaction and feedback between cell mechanics and fate specification in vertebrate gastrulation publication_identifier: isbn: - ' 978-3-99078-025-1 ' issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '9350' relation: part_of_dissertation status: public status: public supervisor: - first_name: Carl-Philipp J full_name: Heisenberg, Carl-Philipp J id: 39427864-F248-11E8-B48F-1D18A9856A87 last_name: Heisenberg orcid: 0000-0002-0912-4566 title: Remodeling of E-cadherin-mediated contacts via cortical flows tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: dissertation user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2022' ... --- _id: '11473' abstract: - lang: eng text: "The polaron model is a basic model of quantum field theory describing a single particle\r\ninteracting with a bosonic field. It arises in many physical contexts. We are mostly concerned\r\nwith models applicable in the context of an impurity atom in a Bose-Einstein condensate as\r\nwell as the problem of electrons moving in polar crystals.\r\nThe model has a simple structure in which the interaction of the particle with the field is given\r\nby a term linear in the field’s creation and annihilation operators. In this work, we investigate\r\nthe properties of this model by providing rigorous estimates on various energies relevant to the\r\nproblem. The estimates are obtained, for the most part, by suitable operator techniques which\r\nconstitute the principal mathematical substance of the thesis.\r\nThe first application of these techniques is to derive the polaron model rigorously from first\r\nprinciples, i.e., from a full microscopic quantum-mechanical many-body problem involving an\r\nimpurity in an otherwise homogeneous system. We accomplish this for the N + 1 Bose gas\r\nin the mean-field regime by showing that a suitable polaron-type Hamiltonian arises at weak\r\ninteractions as a low-energy effective theory for this problem.\r\nIn the second part, we investigate rigorously the ground state of the model at fixed momentum\r\nand for large values of the coupling constant. Qualitatively, the system is expected to display\r\na transition from the quasi-particle behavior at small momenta, where the dispersion relation\r\nis parabolic and the particle moves through the medium dragging along a cloud of phonons, to\r\nthe radiative behavior at larger momenta where the polaron decelerates and emits free phonons.\r\nAt the same time, in the strong coupling regime, the bosonic field is expected to behave purely\r\nclassically. Accordingly, the effective mass of the polaron at strong coupling is conjectured to\r\nbe asymptotically equal to the one obtained from the semiclassical counterpart of the problem,\r\nfirst studied by Landau and Pekar in the 1940s. For polaron models with regularized form\r\nfactors and phonon dispersion relations of superfluid type, i.e., bounded below by a linear\r\nfunction of the wavenumbers for all phonon momenta as in the interacting Bose gas, we prove\r\nthat for a large window of momenta below the radiation threshold, the energy-momentum\r\nrelation at strong coupling is indeed essentially a parabola with semi-latus rectum equal to the\r\nLandau–Pekar effective mass, as expected.\r\nFor the Fröhlich polaron describing electrons in polar crystals where the dispersion relation is\r\nof the optical type and the form factor is formally UV–singular due to the nature of the point\r\ncharge-dipole interaction, we are able to give the corresponding upper bound. In contrast to\r\nthe regular case, this requires the inclusion of the quantum fluctuations of the phonon field,\r\nwhich makes the problem considerably more difficult.\r\nThe results are supplemented by studies on the absolute ground-state energy at strong coupling,\r\na proof of the divergence of the effective mass with the coupling constant for a wide class of\r\npolaron models, as well as the discussion of the apparent UV singularity of the Fröhlich model\r\nand the application of the techniques used for its removal for the energy estimates.\r\n" acknowledged_ssus: - _id: SSU alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Krzysztof full_name: Mysliwy, Krzysztof id: 316457FC-F248-11E8-B48F-1D18A9856A87 last_name: Mysliwy citation: ama: 'Mysliwy K. Polarons in Bose gases and polar crystals: Some rigorous energy estimates. 2022. doi:10.15479/at:ista:11473' apa: 'Mysliwy, K. (2022). Polarons in Bose gases and polar crystals: Some rigorous energy estimates. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:11473' chicago: 'Mysliwy, Krzysztof. “Polarons in Bose Gases and Polar Crystals: Some Rigorous Energy Estimates.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:11473.' ieee: 'K. Mysliwy, “Polarons in Bose gases and polar crystals: Some rigorous energy estimates,” Institute of Science and Technology Austria, 2022.' ista: 'Mysliwy K. 2022. Polarons in Bose gases and polar crystals: Some rigorous energy estimates. Institute of Science and Technology Austria.' mla: 'Mysliwy, Krzysztof. Polarons in Bose Gases and Polar Crystals: Some Rigorous Energy Estimates. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:11473.' short: 'K. Mysliwy, Polarons in Bose Gases and Polar Crystals: Some Rigorous Energy Estimates, Institute of Science and Technology Austria, 2022.' date_created: 2022-06-30T12:15:03Z date_published: 2022-07-01T00:00:00Z date_updated: 2023-09-07T13:43:52Z day: '01' ddc: - '515' - '539' degree_awarded: PhD department: - _id: GradSch - _id: RoSe doi: 10.15479/at:ista:11473 ec_funded: 1 file: - access_level: open_access checksum: 7970714a20a6052f75fb27a6c3e9976e content_type: application/pdf creator: kmysliwy date_created: 2022-07-05T08:12:56Z date_updated: 2022-07-05T08:12:56Z file_id: '11486' file_name: thes1_no_isbn_2_1b.pdf file_size: 1830973 relation: main_file success: 1 - access_level: closed checksum: 647a2011fdf56277096c9350fefe1097 content_type: application/zip creator: kmysliwy date_created: 2022-07-05T08:15:52Z date_updated: 2022-07-05T08:17:12Z file_id: '11487' file_name: thes_source.zip file_size: 5831060 relation: source_file file_date_updated: 2022-07-05T08:17:12Z has_accepted_license: '1' language: - iso: eng month: '07' oa: 1 oa_version: Published Version page: '138' project: - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '10564' relation: part_of_dissertation status: public - id: '8705' relation: part_of_dissertation status: public status: public supervisor: - first_name: Robert full_name: Seiringer, Robert id: 4AFD0470-F248-11E8-B48F-1D18A9856A87 last_name: Seiringer orcid: 0000-0002-6781-0521 title: 'Polarons in Bose gases and polar crystals: Some rigorous energy estimates' type: dissertation user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 year: '2022' ...