---
_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
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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:
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content_type: application/pdf
creator: dboocock
date_created: 2023-05-17T13:39:54Z
date_updated: 2023-05-19T07:04:25Z
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embargo_to: open_access
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creator: dboocock
date_created: 2023-05-17T13:39:53Z
date_updated: 2023-05-17T14:35:13Z
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relation: source_file
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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:
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date_updated: 2023-05-02T07:43:18Z
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success: 1
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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:
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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
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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
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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:
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creator: pradler
date_created: 2023-10-04T10:11:53Z
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file_size: 114932847
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date_updated: 2023-10-04T10:28:35Z
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embargo_to: open_access
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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
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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
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checksum: 0bebbdee0773443959e1f6ab8caf281f
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creator: cchlebak
date_created: 2023-01-31T15:11:51Z
date_updated: 2023-07-10T22:30:04Z
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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
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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
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date_updated: 2023-12-08T23:30:04Z
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date_updated: 2023-12-08T23:30:04Z
embargo_to: open_access
file_id: '12943'
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file_size: 265319
relation: source_file
file_date_updated: 2023-12-08T23:30:04Z
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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
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date_updated: 2022-09-08T21:50:34Z
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date_created: 2022-09-08T21:50:42Z
date_updated: 2022-09-12T11:24:21Z
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creator: ashute
date_created: 2022-09-09T12:05:00Z
date_updated: 2022-09-12T11:24:21Z
file_id: '12078'
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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:
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checksum: e9609bc4e8f8e20146fc1125fd4f1bf7
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creator: cchlebak
date_created: 2022-04-07T08:11:34Z
date_updated: 2022-04-07T08:11:34Z
file_id: '11129'
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file_size: 11906472
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creator: cchlebak
date_created: 2022-04-07T08:11:51Z
date_updated: 2022-04-07T08:11:51Z
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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'
...