---
_id: '14711'
abstract:
- lang: eng
text: "In nature, different species find their niche in a range of environments,
each with its unique characteristics. While some thrive in uniform (homogeneous)
landscapes where environmental conditions stay relatively consistent across space,
others traverse the complexities of spatially heterogeneous terrains. Comprehending
how species are distributed and how they interact within these landscapes holds
the key to gaining insights into their evolutionary dynamics while also informing
conservation and management strategies.\r\n\r\nFor species inhabiting heterogeneous
landscapes, when the rate of dispersal is low compared to spatial fluctuations
in selection pressure, localized adaptations may emerge. Such adaptation in response
to varying selection strengths plays an important role in the persistence of populations
in our rapidly changing world. Hence, species in nature are continuously in a
struggle to adapt to local environmental conditions, to ensure their continued
survival. Natural populations can often adapt in time scales short enough for
evolutionary changes to influence ecological dynamics and vice versa, thereby
creating a feedback between evolution and demography. The analysis of this feedback
and the relative contributions of gene flow, demography, drift, and natural selection
to genetic variation and differentiation has remained a recurring theme in evolutionary
biology. Nevertheless, the effective role of these forces in maintaining variation
and shaping patterns of diversity is not fully understood. Even in homogeneous
environments devoid of local adaptations, such understanding remains elusive.
Understanding this feedback is crucial, for example in determining the conditions
under which extinction risk can be mitigated in peripheral populations subject
to deleterious mutation accumulation at the edges of species’ ranges\r\nas well
as in highly fragmented populations.\r\n\r\nIn this thesis we explore both uniform
and spatially heterogeneous metapopulations, investigating and providing theoretical
insights into the dynamics of local adaptation in the latter and examining the
dynamics of load and extinction as well as the impact of joint ecological and
evolutionary (eco-evolutionary) dynamics in the former. The thesis is divided
into 5 chapters.\r\n\r\nChapter 1 provides a general introduction into the subject
matter, clarifying concepts and ideas used throughout the thesis. In chapter 2,
we explore how fast a species distributed across a heterogeneous landscape adapts
to changing conditions marked by alterations in carrying capacity, selection pressure,
and migration rate.\r\n\r\nIn chapter 3, we investigate how migration selection
and drift influences adaptation and the maintenance of variation in a metapopulation
with three habitats, an extension of previous models of adaptation in two habitats.
We further develop analytical approximations for the critical threshold required
for polymorphism to persist.\r\n\r\nThe focus of chapter 4 of the thesis is on
understanding the interplay between ecology and evolution as coupled processes.
We investigate how eco-evolutionary feedback between migration, selection, drift,
and demography influences eco-evolutionary outcomes in marginal populations subject
to deleterious mutation accumulation. Using simulations as well as theoretical
approximations of the coupled dynamics of population size and allele frequency,
we analyze how gene flow from a large mainland source influences genetic load
and population size on an island (i.e., in a marginal population) under genetically
realistic assumptions. Analyses of this sort are important because small isolated
populations, are repeatedly affected by complex interactions between ecological
and evolutionary processes, which can lead to their death. Understanding these
interactions can therefore provide an insight into the conditions under which
extinction risk can be mitigated in peripheral populations thus, contributing
to conservation and restoration efforts.\r\n\r\nChapter 5 extends the analysis
in chapter 4 to consider the dynamics of load (due to deleterious mutation accumulation)
and extinction risk in a metapopulation. We explore the role of gene flow, selection,
and dominance on load and extinction risk and further pinpoint critical thresholds
required for metapopulation persistence.\r\n\r\nOverall this research contributes
to our understanding of ecological and evolutionary mechanisms that shape species’
persistence in fragmented landscapes, a crucial foundation for successful conservation
efforts and biodiversity management."
acknowledged_ssus:
- _id: SSU
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Oluwafunmilola O
full_name: Olusanya, Oluwafunmilola O
id: 41AD96DC-F248-11E8-B48F-1D18A9856A87
last_name: Olusanya
orcid: 0000-0003-1971-8314
citation:
ama: Olusanya OO. Local adaptation, genetic load and extinction in metapopulations.
2024. doi:10.15479/at:ista:14711
apa: Olusanya, O. O. (2024). Local adaptation, genetic load and extinction in
metapopulations. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:14711
chicago: Olusanya, Oluwafunmilola O. “Local Adaptation, Genetic Load and Extinction
in Metapopulations.” Institute of Science and Technology Austria, 2024. https://doi.org/10.15479/at:ista:14711.
ieee: O. O. Olusanya, “Local adaptation, genetic load and extinction in metapopulations,”
Institute of Science and Technology Austria, 2024.
ista: Olusanya OO. 2024. Local adaptation, genetic load and extinction in metapopulations.
Institute of Science and Technology Austria.
mla: Olusanya, Oluwafunmilola O. Local Adaptation, Genetic Load and Extinction
in Metapopulations. Institute of Science and Technology Austria, 2024, doi:10.15479/at:ista:14711.
short: O.O. Olusanya, Local Adaptation, Genetic Load and Extinction in Metapopulations,
Institute of Science and Technology Austria, 2024.
date_created: 2023-12-26T22:49:53Z
date_published: 2024-01-19T00:00:00Z
date_updated: 2024-01-26T12:00:54Z
day: '19'
ddc:
- '576'
degree_awarded: PhD
department:
- _id: NiBa
- _id: GradSch
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ec_funded: 1
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month: '01'
oa: 1
oa_version: Published Version
page: '183'
project:
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call_identifier: H2020
grant_number: '665385'
name: International IST Doctoral Program
- _id: c08d3278-5a5b-11eb-8a69-fdb09b55f4b8
grant_number: P32896
name: Causes and consequences of population fragmentation
- _id: 34c872fe-11ca-11ed-8bc3-8534b82131e6
grant_number: '26380'
name: Polygenic Adaptation in a Metapopulation
publication_identifier:
issn:
- 2663 - 337X
publication_status: published
publisher: Institute of Science and Technology Austria
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supervisor:
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full_name: Barton, Nicholas H
id: 4880FE40-F248-11E8-B48F-1D18A9856A87
last_name: Barton
orcid: 0000-0002-8548-5240
- first_name: Jitka
full_name: Polechova, Jitka
last_name: Polechova
- first_name: Himani
full_name: Sachdeva, Himani
last_name: Sachdeva
title: Local adaptation, genetic load and extinction in metapopulations
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...
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_id: '14821'
alternative_title:
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article_processing_charge: No
author:
- first_name: Heloisa
full_name: Chiossi, Heloisa
id: 2BBA502C-F248-11E8-B48F-1D18A9856A87
last_name: Chiossi
citation:
ama: Chiossi HSC. Adaptive hierarchical representations in the hippocampus. 2024.
doi:10.15479/at:ista:14821
apa: Chiossi, H. S. C. (2024). Adaptive hierarchical representations in the hippocampus.
Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:14821
chicago: Chiossi, Heloisa S. C. “Adaptive Hierarchical Representations in the Hippocampus.”
Institute of Science and Technology Austria, 2024. https://doi.org/10.15479/at:ista:14821.
ieee: H. S. C. Chiossi, “Adaptive hierarchical representations in the hippocampus,”
Institute of Science and Technology Austria, 2024.
ista: Chiossi HSC. 2024. Adaptive hierarchical representations in the hippocampus.
Institute of Science and Technology Austria.
mla: Chiossi, Heloisa S. C. Adaptive Hierarchical Representations in the Hippocampus.
Institute of Science and Technology Austria, 2024, doi:10.15479/at:ista:14821.
short: H.S.C. Chiossi, Adaptive Hierarchical Representations in the Hippocampus,
Institute of Science and Technology Austria, 2024.
date_created: 2024-01-16T14:25:21Z
date_published: 2024-01-19T00:00:00Z
date_updated: 2024-02-01T09:50:29Z
day: '19'
ddc:
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degree_awarded: PhD
department:
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- _id: JoCs
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ec_funded: 1
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date_created: 2024-01-19T11:03:59Z
date_updated: 2024-01-19T11:03:59Z
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language:
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month: '01'
oa_version: Published Version
page: '89'
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
status: public
supervisor:
- first_name: Jozsef L
full_name: Csicsvari, Jozsef L
id: 3FA14672-F248-11E8-B48F-1D18A9856A87
last_name: Csicsvari
orcid: 0000-0002-5193-4036
title: Adaptive hierarchical representations in the hippocampus
type: dissertation
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2024'
...
---
_id: '15020'
abstract:
- lang: eng
text: "This thesis consists of four distinct pieces of work within theoretical biology,
with two themes in common: the concept of optimization in biological systems,
and the use of information-theoretic tools to quantify biological stochasticity
and statistical uncertainty.\r\nChapter 2 develops a statistical framework for
studying biological systems which we believe to be optimized for a particular
utility function, such as retinal neurons conveying information about visual stimuli.
We formalize such beliefs as maximum-entropy Bayesian priors, constrained by the
expected utility. We explore how such priors aid inference of system parameters
with limited data and enable optimality hypothesis testing: is the utility higher
than by chance?\r\nChapter 3 examines the ultimate biological optimization process:
evolution by natural selection. As some individuals survive and reproduce more
successfully than others, populations evolve towards fitter genotypes and phenotypes.
We formalize this as accumulation of genetic information, and use population genetics
theory to study how much such information can be accumulated per generation and
maintained in the face of random mutation and genetic drift. We identify the population
size and fitness variance as the key quantities that control information accumulation
and maintenance.\r\nChapter 4 reuses the concept of genetic information from Chapter
3, but from a different perspective: we ask how much genetic information organisms
actually need, in particular in the context of gene regulation. For example, how
much information is needed to bind transcription factors at correct locations
within the genome? Population genetics provides us with a refined answer: with
an increasing population size, populations achieve higher fitness by maintaining
more genetic information. Moreover, regulatory parameters experience selection
pressure to optimize the fitness-information trade-off, i.e. minimize the information
needed for a given fitness. This provides an evolutionary derivation of the optimization
priors introduced in Chapter 2.\r\nChapter 5 proves an upper bound on mutual information
between a signal and a communication channel output (such as neural activity).
Mutual information is an important utility measure for biological systems, but
its practical use can be difficult due to the large dimensionality of many biological
channels. Sometimes, a lower bound on mutual information is computed by replacing
the high-dimensional channel outputs with decodes (signal estimates). Our result
provides a corresponding upper bound, provided that the decodes are the maximum
posterior estimates of the signal."
acknowledged_ssus:
- _id: ScienComp
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Michal
full_name: Hledik, Michal
id: 4171253A-F248-11E8-B48F-1D18A9856A87
last_name: Hledik
citation:
ama: Hledik M. Genetic information and biological optimization. 2024. doi:10.15479/at:ista:15020
apa: Hledik, M. (2024). Genetic information and biological optimization.
Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:15020
chicago: Hledik, Michal. “Genetic Information and Biological Optimization.” Institute
of Science and Technology Austria, 2024. https://doi.org/10.15479/at:ista:15020.
ieee: M. Hledik, “Genetic information and biological optimization,” Institute of
Science and Technology Austria, 2024.
ista: Hledik M. 2024. Genetic information and biological optimization. Institute
of Science and Technology Austria.
mla: Hledik, Michal. Genetic Information and Biological Optimization. Institute
of Science and Technology Austria, 2024, doi:10.15479/at:ista:15020.
short: M. Hledik, Genetic Information and Biological Optimization, Institute of
Science and Technology Austria, 2024.
date_created: 2024-02-23T14:02:04Z
date_published: 2024-02-23T00:00:00Z
date_updated: 2024-03-06T14:22:52Z
day: '23'
ddc:
- '576'
- '519'
degree_awarded: PhD
department:
- _id: GradSch
- _id: NiBa
- _id: GaTk
doi: 10.15479/at:ista:15020
ec_funded: 1
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keyword:
- Theoretical biology
- Optimality
- Evolution
- Information
language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
page: '158'
project:
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call_identifier: H2020
grant_number: '665385'
name: International IST Doctoral Program
- _id: 2665AAFE-B435-11E9-9278-68D0E5697425
grant_number: RGP0034/2018
name: Can evolution minimize spurious signaling crosstalk to reach optimal performance?
- _id: bd6958e0-d553-11ed-ba76-86eba6a76c00
grant_number: '101055327'
name: Understanding the evolution of continuous genomes
publication_identifier:
issn:
- 2663 - 337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
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relation: part_of_dissertation
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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
- first_name: Gašper
full_name: Tkačik, Gašper
id: 3D494DCA-F248-11E8-B48F-1D18A9856A87
last_name: Tkačik
orcid: 0000-0002-6699-1455
title: Genetic information and biological optimization
type: dissertation
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2024'
...
---
_id: '15101'
acknowledged_ssus:
- _id: EM-Fac
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: JingJing
full_name: Chen, JingJing
id: 2C4E65C8-F248-11E8-B48F-1D18A9856A87
last_name: Chen
citation:
ama: Chen J. Developmental transformation of nanodomain coupling between Ca2+ channels
and release sensors at a central GABAergic synapse. 2024. doi:10.15479/at:ista:15101
apa: Chen, J. (2024). Developmental transformation of nanodomain coupling between
Ca2+ channels and release sensors at a central GABAergic synapse. Institute
of Science and Technology Austria. https://doi.org/10.15479/at:ista:15101
chicago: Chen, JingJing. “Developmental Transformation of Nanodomain Coupling between
Ca2+ Channels and Release Sensors at a Central GABAergic Synapse.” Institute of
Science and Technology Austria, 2024. https://doi.org/10.15479/at:ista:15101.
ieee: J. Chen, “Developmental transformation of nanodomain coupling between Ca2+
channels and release sensors at a central GABAergic synapse,” Institute of Science
and Technology Austria, 2024.
ista: Chen J. 2024. Developmental transformation of nanodomain coupling between
Ca2+ channels and release sensors at a central GABAergic synapse. Institute of
Science and Technology Austria.
mla: Chen, JingJing. Developmental Transformation of Nanodomain Coupling between
Ca2+ Channels and Release Sensors at a Central GABAergic Synapse. Institute
of Science and Technology Austria, 2024, doi:10.15479/at:ista:15101.
short: J. Chen, Developmental Transformation of Nanodomain Coupling between Ca2+
Channels and Release Sensors at a Central GABAergic Synapse, Institute of Science
and Technology Austria, 2024.
date_created: 2024-03-11T10:09:54Z
date_published: 2024-03-11T00:00:00Z
date_updated: 2024-03-14T13:14:19Z
day: '11'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: GradSch
- _id: PeJo
doi: 10.15479/at:ista:15101
ec_funded: 1
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file_date_updated: 2024-03-12T07:12:17Z
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language:
- iso: eng
month: '03'
oa_version: Published Version
page: '84'
project:
- _id: 25B7EB9E-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '692692'
name: Biophysics and circuit function of a giant cortical glumatergic synapse
- _id: 25C5A090-B435-11E9-9278-68D0E5697425
call_identifier: FWF
grant_number: Z00312
name: The Wittgenstein Prize
- _id: bd88be38-d553-11ed-ba76-81d5a70a6ef5
grant_number: P36232
name: Mechanisms of GABA release in hippocampal circuits
- _id: 26B66A3E-B435-11E9-9278-68D0E5697425
grant_number: '25383'
name: Development of nanodomain coupling between Ca2+ channels and release sensors
at a central inhibitory synapse
publication_identifier:
issn:
- 2663 - 337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '14843'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Peter M
full_name: Jonas, Peter M
id: 353C1B58-F248-11E8-B48F-1D18A9856A87
last_name: Jonas
orcid: 0000-0001-5001-4804
title: Developmental transformation of nanodomain coupling between Ca2+ channels and
release sensors at a central GABAergic synapse
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: '2024'
...
---
_id: '15094'
abstract:
- lang: eng
text: "Point sets, geometric networks, and arrangements of hyperplanes are fundamental
objects in\r\ndiscrete geometry that have captivated mathematicians for centuries,
if not millennia. This\r\nthesis seeks to cast new light on these structures by
illustrating specific instances where a\r\ntopological perspective, specifically
through discrete Morse theory and persistent homology,\r\nprovides valuable insights.\r\n\r\nAt
first glance, the topology of these geometric objects might seem uneventful: point
sets\r\nessentially lack of topology, arrangements of hyperplanes are a decomposition
of Rd, which\r\nis a contractible space, and the topology of a network primarily
involves the enumeration\r\nof connected components and cycles within the network.
However, beneath this apparent\r\nsimplicity, there lies an array of intriguing
structures, a small subset of which will be uncovered\r\nin this thesis.\r\n\r\nFocused
on three case studies, each addressing one of the mentioned objects, this work\r\nwill
showcase connections that intertwine topology with diverse fields such as combinatorial\r\ngeometry,
algorithms and data structures, and emerging applications like spatial biology.\r\n\r\n"
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Sebastiano
full_name: Cultrera di Montesano, Sebastiano
id: 34D2A09C-F248-11E8-B48F-1D18A9856A87
last_name: Cultrera di Montesano
orcid: 0000-0001-6249-0832
citation:
ama: Cultrera di Montesano S. Persistence and Morse theory for discrete geometric
structures. 2024. doi:10.15479/at:ista:15094
apa: Cultrera di Montesano, S. (2024). Persistence and Morse theory for discrete
geometric structures. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:15094
chicago: Cultrera di Montesano, Sebastiano. “Persistence and Morse Theory for Discrete
Geometric Structures.” Institute of Science and Technology Austria, 2024. https://doi.org/10.15479/at:ista:15094.
ieee: S. Cultrera di Montesano, “Persistence and Morse theory for discrete geometric
structures,” Institute of Science and Technology Austria, 2024.
ista: Cultrera di Montesano S. 2024. Persistence and Morse theory for discrete geometric
structures. Institute of Science and Technology Austria.
mla: Cultrera di Montesano, Sebastiano. Persistence and Morse Theory for Discrete
Geometric Structures. Institute of Science and Technology Austria, 2024, doi:10.15479/at:ista:15094.
short: S. Cultrera di Montesano, Persistence and Morse Theory for Discrete Geometric
Structures, Institute of Science and Technology Austria, 2024.
date_created: 2024-03-08T15:28:10Z
date_published: 2024-03-08T00:00:00Z
date_updated: 2024-03-20T09:36:57Z
day: '08'
ddc:
- '514'
- '500'
- '516'
degree_awarded: PhD
department:
- _id: GradSch
- _id: HeEd
doi: 10.15479/at:ista:15094
ec_funded: 1
file:
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file_size: 4746234
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language:
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month: '03'
oa: 1
oa_version: Published Version
page: '108'
project:
- _id: 266A2E9E-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '788183'
name: Alpha Shape Theory Extended
- _id: 268116B8-B435-11E9-9278-68D0E5697425
call_identifier: FWF
grant_number: Z00342
name: The Wittgenstein Prize
- _id: 0aa4bc98-070f-11eb-9043-e6fff9c6a316
grant_number: I4887
name: Discretization in Geometry and Dynamics
- _id: 2561EBF4-B435-11E9-9278-68D0E5697425
call_identifier: FWF
grant_number: I02979-N35
name: Persistence and stability of geometric complexes
publication_identifier:
issn:
- 2663 - 337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '11660'
relation: part_of_dissertation
status: public
- id: '11658'
relation: part_of_dissertation
status: public
- id: '13182'
relation: part_of_dissertation
status: public
- id: '15090'
relation: part_of_dissertation
status: public
- id: '15091'
relation: part_of_dissertation
status: public
- id: '15093'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Herbert
full_name: Edelsbrunner, Herbert
id: 3FB178DA-F248-11E8-B48F-1D18A9856A87
last_name: Edelsbrunner
orcid: 0000-0002-9823-6833
title: Persistence and Morse theory for discrete geometric structures
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: '2024'
...
---
_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
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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'
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file_size: 23029260
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date_created: 2023-03-08T15:08:46Z
date_updated: 2023-03-08T15:08:46Z
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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: '12809'
abstract:
- lang: eng
text: "Understanding the mechanisms of learning and memory formation has always
been one of\r\nthe main goals in neuroscience. Already Pavlov (1927) in his early
days has used his classic\r\nconditioning experiments to study the neural mechanisms
governing behavioral adaptation.\r\nWhat was not known back then was that the
part of the brain that is largely responsible for\r\nthis type of associative
learning is the cerebellum.\r\nSince then, plenty of theories on cerebellar learning
have emerged. Despite their differences,\r\none thing they all have in common
is that learning relies on synaptic and intrinsic plasticity.\r\nThe goal of my
PhD project was to unravel the molecular mechanisms underlying synaptic\r\nplasticity
in two synapses that have been shown to be implicated in motor learning, in an\r\neffort
to understand how learning and memory formation are processed in the cerebellum.\r\nOne
of the earliest and most well-known cerebellar theories postulates that motor
learning\r\nlargely depends on long-term depression at the parallel fiber-Purkinje
cell (PC-PC) synapse.\r\nHowever, the discovery of other types of plasticity in
the cerebellar circuitry, like long-term\r\npotentiation (LTP) at the PC-PC synapse,
potentiation of molecular layer interneurons (MLIs),\r\nand plasticity transfer
from the cortex to the cerebellar/ vestibular nuclei has increased the\r\npopularity
of the idea that multiple sites of plasticity might be involved in learning.\r\nStill
a lot remains unknown about the molecular mechanisms responsible for these types
of\r\nplasticity and whether they occur during physiological learning.\r\nIn the
first part of this thesis we have analyzed the variation and nanodistribution
of voltagegated calcium channels (VGCCs) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic
acid\r\ntype glutamate receptors (AMPARs) on the parallel fiber-Purkinje cell
synapse after vestibuloocular reflex phase reversal adaptation, a behavior that
has been suggested to rely on PF-PC\r\nLTP. We have found that on the last day
of adaptation there is no learning trace in form of\r\nVGCCs nor AMPARs variation
at the PF-PC synapse, but instead a decrease in the number of\r\nPF-PC synapses.
These data seem to support the view that learning is only stored in the\r\ncerebellar
cortex in an initial learning phase, being transferred later to the vestibular
nuclei.\r\nNext, we have studied the role of MLIs in motor learning using a relatively
simple and well characterized behavioral paradigm – horizontal optokinetic reflex
(HOKR) adaptation. We\r\nhave found behavior-induced MLI potentiation in form
of release probability increase that\r\ncould be explained by the increase of
VGCCs at the presynaptic side. Our results strengthen\r\nthe idea of distributed
cerebellar plasticity contributing to learning and provide a novel\r\nmechanism
for release probability increase. "
acknowledged_ssus:
- _id: EM-Fac
- _id: Bio
- _id: PreCl
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Catarina
full_name: Alcarva, Catarina
id: 3A96634C-F248-11E8-B48F-1D18A9856A87
last_name: Alcarva
citation:
ama: 'Alcarva C. Plasticity in the cerebellum: What molecular mechanisms are behind
physiological learning. 2023. doi:10.15479/at:ista:12809'
apa: 'Alcarva, C. (2023). Plasticity in the cerebellum: What molecular mechanisms
are behind physiological learning. Institute of Science and Technology Austria.
https://doi.org/10.15479/at:ista:12809'
chicago: 'Alcarva, Catarina. “Plasticity in the Cerebellum: What Molecular Mechanisms
Are behind Physiological Learning.” Institute of Science and Technology Austria,
2023. https://doi.org/10.15479/at:ista:12809.'
ieee: 'C. Alcarva, “Plasticity in the cerebellum: What molecular mechanisms are
behind physiological learning,” Institute of Science and Technology Austria, 2023.'
ista: 'Alcarva C. 2023. Plasticity in the cerebellum: What molecular mechanisms
are behind physiological learning. Institute of Science and Technology Austria.'
mla: 'Alcarva, Catarina. Plasticity in the Cerebellum: What Molecular Mechanisms
Are behind Physiological Learning. Institute of Science and Technology Austria,
2023, doi:10.15479/at:ista:12809.'
short: 'C. Alcarva, Plasticity in the Cerebellum: What Molecular Mechanisms Are
behind Physiological Learning, Institute of Science and Technology Austria, 2023.'
date_created: 2023-04-06T07:54:09Z
date_published: 2023-04-06T00:00:00Z
date_updated: 2023-04-26T12:16:56Z
day: '06'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: GradSch
- _id: RySh
doi: 10.15479/at:ista:12809
file:
- access_level: closed
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content_type: application/pdf
creator: cchlebak
date_created: 2023-04-07T06:16:06Z
date_updated: 2023-04-07T06:16:06Z
embargo: 2024-04-07
embargo_to: open_access
file_id: '12814'
file_name: Thesis_CatarinaAlcarva_final pdfA.pdf
file_size: 9881969
relation: main_file
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content_type: application/pdf
creator: cchlebak
date_created: 2023-04-07T06:17:11Z
date_updated: 2023-04-07T06:17:11Z
file_id: '12815'
file_name: Thesis_CatarinaAlcarva_final_for printing.pdf
file_size: 44201583
relation: source_file
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checksum: 0317bf7f457bb585f99d453ffa69eb53
content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
creator: cchlebak
date_created: 2023-04-07T06:18:05Z
date_updated: 2023-04-07T06:18:05Z
file_id: '12816'
file_name: Thesis_CatarinaAlcarva_final.docx
file_size: 84731244
relation: source_file
file_date_updated: 2023-04-07T06:18:05Z
has_accepted_license: '1'
language:
- iso: eng
month: '04'
oa_version: Published Version
page: '115'
project:
- _id: 267DFB90-B435-11E9-9278-68D0E5697425
name: 'Plasticity in the cerebellum: Which molecular mechanisms are behind physiological
learning?'
publication_identifier:
issn:
- 2663 - 337X
publication_status: published
publisher: Institute of Science and Technology Austria
status: public
supervisor:
- first_name: Ryuichi
full_name: Shigemoto, Ryuichi
id: 499F3ABC-F248-11E8-B48F-1D18A9856A87
last_name: Shigemoto
orcid: 0000-0001-8761-9444
title: 'Plasticity in the cerebellum: What molecular mechanisms are behind physiological
learning'
type: dissertation
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2023'
...
---
_id: '12826'
abstract:
- lang: eng
text: "During navigation, animals can infer the structure of the environment by
computing the optic flow cues elicited by their own movements, and subsequently
use this information to instruct proper locomotor actions. These computations
require a panoramic assessment of the visual environment in order to disambiguate
similar sensory experiences that may require distinct behavioral responses. The
estimation of the global motion patterns is therefore essential for successful
navigation. Yet, our understanding of the algorithms and implementations that
enable coherent panoramic visual perception remains scarce. Here I pursue this
problem by dissecting the functional aspects of interneuronal communication in
the lobula plate tangential cell network in Drosophila melanogaster. The results
presented in the thesis demonstrate that the basis for effective interpretation
of the optic flow in this circuit are stereotyped synaptic connections that mediate
the formation of distinct subnetworks, each extracting a particular pattern of
global motion. \r\nFirstly, I show that gap junctions are essential for a correct
interpretation of binocular motion cues by horizontal motion-sensitive cells.
HS cells form electrical synapses with contralateral H2 neurons that are involved
in detecting yaw rotation and translation. I developed an FlpStop-mediated mutant
of a gap junction protein ShakB that disrupts these electrical synapses. While
the loss of electrical synapses does not affect the tuning of the direction selectivity
in HS neurons, it severely alters their sensitivity to horizontal motion in the
contralateral side. These physiological changes result in an inappropriate integration
of binocular motion cues in walking animals. While wild-type flies form a binocular
perception of visual motion by non-linear integration of monocular optic flow
cues, the mutant flies sum the monocular inputs linearly. These results indicate
that rather than averaging signals in neighboring neurons, gap-junctions operate
in conjunction with chemical synapses to mediate complex non-linear optic flow
computations.\r\nSecondly, I show that stochastic manipulation of neuronal activity
in the lobula plate tangential cell network is a powerful approach to study the
neuronal implementation of optic flow-based navigation in flies. Tangential neurons
form multiple subnetworks, each mediating course-stabilizing response to a particular
global pattern of visual motion. Application of genetic mosaic techniques can
provide sparse optogenetic activation of HS cells in numerous combinations. These
distinct combinations of activated neurons drive an array of distinct behavioral
responses, providing important insights into how visuomotor transformation is
performed in the lobula plate tangential cell network. This approach can be complemented
by stochastic silencing of tangential neurons, enabling direct assessment of the
functional role of individual tangential neurons in the processing of specific
visual motion patterns.\r\n\tTaken together, the findings presented in this thesis
suggest that establishing specific activity patterns of tangential cells via stereotyped
synaptic connectivity is a key to efficient optic flow-based navigation in Drosophila
melanogaster."
acknowledged_ssus:
- _id: Bio
- _id: LifeSc
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Victoria
full_name: Pokusaeva, Victoria
id: 3184041C-F248-11E8-B48F-1D18A9856A87
last_name: Pokusaeva
orcid: 0000-0001-7660-444X
citation:
ama: Pokusaeva V. Neural control of optic flow-based navigation in Drosophila melanogaster.
2023. doi:10.15479/at:ista:12826
apa: Pokusaeva, V. (2023). Neural control of optic flow-based navigation in Drosophila
melanogaster. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12826
chicago: Pokusaeva, Victoria. “Neural Control of Optic Flow-Based Navigation in
Drosophila Melanogaster.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:12826.
ieee: V. Pokusaeva, “Neural control of optic flow-based navigation in Drosophila
melanogaster,” Institute of Science and Technology Austria, 2023.
ista: Pokusaeva V. 2023. Neural control of optic flow-based navigation in Drosophila
melanogaster. Institute of Science and Technology Austria.
mla: Pokusaeva, Victoria. Neural Control of Optic Flow-Based Navigation in Drosophila
Melanogaster. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:12826.
short: V. Pokusaeva, Neural Control of Optic Flow-Based Navigation in Drosophila
Melanogaster, Institute of Science and Technology Austria, 2023.
date_created: 2023-04-14T14:56:04Z
date_published: 2023-04-18T00:00:00Z
date_updated: 2023-06-23T09:47:36Z
day: '18'
ddc:
- '570'
- '571'
degree_awarded: PhD
department:
- _id: MaJö
- _id: GradSch
doi: 10.15479/at:ista:12826
ec_funded: 1
file:
- access_level: closed
checksum: 5f589a9af025f7eeebfd0c186209913e
content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
creator: vpokusae
date_created: 2023-04-20T09:14:38Z
date_updated: 2023-04-20T09:26:51Z
file_id: '12857'
file_name: Thesis_Pokusaeva.docx
file_size: 14507243
relation: source_file
- access_level: open_access
checksum: bbeed76db45a996b4c91a9abe12ce0ec
content_type: application/pdf
creator: vpokusae
date_created: 2023-04-20T09:14:44Z
date_updated: 2023-04-20T09:14:44Z
file_id: '12858'
file_name: Thesis_Pokusaeva.pdf
file_size: 10090711
relation: main_file
success: 1
file_date_updated: 2023-04-20T09:26:51Z
has_accepted_license: '1'
language:
- iso: eng
month: '04'
oa: 1
oa_version: Published Version
page: '106'
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
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: Neural control of optic flow-based navigation in Drosophila melanogaster
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: '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'
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creator: vkravchu
date_created: 2023-04-19T14:33:52Z
date_updated: 2023-04-20T07:02:59Z
embargo: 2024-04-20
embargo_to: local
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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'
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creator: epeste
date_created: 2023-05-24T16:12:59Z
date_updated: 2023-05-24T16:12:59Z
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file_name: PhD_Thesis_APeste.zip
file_size: 1658293
relation: source_file
file_date_updated: 2023-05-24T16:12:59Z
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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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creator: dboocock
date_created: 2023-05-17T13:39:54Z
date_updated: 2023-05-19T07:04:25Z
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creator: dboocock
date_created: 2023-05-17T13:39:53Z
date_updated: 2023-05-17T14:35:13Z
file_id: '12989'
file_name: thesis_boocock.zip
file_size: 34338567
relation: source_file
file_date_updated: 2023-05-19T07:04:25Z
has_accepted_license: '1'
language:
- iso: eng
month: '05'
oa_version: Published Version
page: '146'
project:
- _id: 2564DBCA-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '665385'
name: International IST Doctoral Program
publication_identifier:
isbn:
- 978-3-99078-032-9
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '8602'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Edouard B
full_name: Hannezo, Edouard B
id: 3A9DB764-F248-11E8-B48F-1D18A9856A87
last_name: Hannezo
orcid: 0000-0001-6005-1561
title: Mechanochemical pattern formation across biological scales
tmp:
image: /images/cc_by_nc_sa.png
legal_code_url: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode
name: Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC
BY-NC-SA 4.0)
short: CC BY-NC-SA (4.0)
type: dissertation
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2023'
...
---
_id: '12885'
abstract:
- lang: eng
text: 'High-performance semiconductors rely upon precise control of heat and charge
transport. This can be achieved by precisely engineering defects in polycrystalline
solids. There are multiple approaches to preparing such polycrystalline semiconductors,
and the transformation of solution-processed colloidal nanoparticles is appealing
because colloidal nanoparticles combine low cost with structural and compositional
tunability along with rich surface chemistry. However, the multiple processes
from nanoparticle synthesis to the final bulk nanocomposites are very complex.
They involve nanoparticle purification, post-synthetic modifications, and finally
consolidation (thermal treatments and densification). All these properties dictate
the final material’s composition and microstructure, ultimately affecting its
functional properties. This thesis explores the synthesis, surface chemistry and
consolidation of colloidal semiconductor nanoparticles into dense solids. In particular,
the transformations that take place during these processes, and their effect on
the material’s transport properties are evaluated. '
acknowledged_ssus:
- _id: EM-Fac
- _id: NanoFab
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Mariano
full_name: Calcabrini, Mariano
id: 45D7531A-F248-11E8-B48F-1D18A9856A87
last_name: Calcabrini
orcid: 0000-0003-4566-5877
citation:
ama: 'Calcabrini M. Nanoparticle-based semiconductor solids: From synthesis to consolidation.
2023. doi:10.15479/at:ista:12885'
apa: 'Calcabrini, M. (2023). Nanoparticle-based semiconductor solids: From synthesis
to consolidation. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:12885'
chicago: 'Calcabrini, Mariano. “Nanoparticle-Based Semiconductor Solids: From Synthesis
to Consolidation.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:12885.'
ieee: 'M. Calcabrini, “Nanoparticle-based semiconductor solids: From synthesis to
consolidation,” Institute of Science and Technology Austria, 2023.'
ista: 'Calcabrini M. 2023. Nanoparticle-based semiconductor solids: From synthesis
to consolidation. Institute of Science and Technology Austria.'
mla: 'Calcabrini, Mariano. Nanoparticle-Based Semiconductor Solids: From Synthesis
to Consolidation. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:12885.'
short: 'M. Calcabrini, Nanoparticle-Based Semiconductor Solids: From Synthesis to
Consolidation, Institute of Science and Technology Austria, 2023.'
date_created: 2023-05-02T07:58:57Z
date_published: 2023-04-28T00:00:00Z
date_updated: 2023-08-14T07:25:26Z
day: '28'
ddc:
- '546'
- '541'
degree_awarded: PhD
department:
- _id: GradSch
- _id: MaIb
doi: 10.15479/at:ista:12885
ec_funded: 1
file:
- access_level: closed
checksum: 9347b0e09425f56fdcede5d3528404dc
content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
creator: mcalcabr
date_created: 2023-05-02T07:43:18Z
date_updated: 2023-05-02T07:43:18Z
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file_size: 99627036
relation: source_file
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content_type: application/pdf
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date_created: 2023-05-02T07:42:45Z
date_updated: 2023-05-02T07:42:45Z
file_id: '12888'
file_name: Thesis_Calcabrini_pdfa.pdf
file_size: 8742220
relation: main_file
success: 1
file_date_updated: 2023-05-02T07:43:18Z
has_accepted_license: '1'
language:
- iso: eng
month: '04'
oa: 1
oa_version: Published Version
page: '82'
project:
- _id: 2564DBCA-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '665385'
name: International IST Doctoral Program
publication_identifier:
isbn:
- 978-3-99078-028-2
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '10806'
relation: part_of_dissertation
status: public
- id: '10042'
relation: part_of_dissertation
status: public
- id: '12237'
relation: part_of_dissertation
status: public
- id: '9118'
relation: part_of_dissertation
status: public
- id: '10123'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Maria
full_name: Ibáñez, Maria
id: 43C61214-F248-11E8-B48F-1D18A9856A87
last_name: Ibáñez
orcid: 0000-0001-5013-2843
title: 'Nanoparticle-based semiconductor solids: From synthesis to consolidation'
type: dissertation
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2023'
...
---
_id: '12891'
abstract:
- lang: eng
text: "The tight spatiotemporal coordination of signaling activity determining embryo\r\npatterning
and the physical processes driving embryo morphogenesis renders\r\nembryonic development
robust, such that key developmental processes can unfold\r\nrelatively normally
even outside of the full embryonic context. For instance, embryonic\r\nstem cell
cultures can recapitulate the hallmarks of gastrulation, i.e. break symmetry\r\nleading
to germ layer formation and morphogenesis, in a very reduced environment.\r\nThis
leads to questions on specific contributions of embryo-specific features, such
as\r\nthe presence of extraembryonic tissues, which are inherently involved in
gastrulation\r\nin the full embryonic context. To address this, we established
zebrafish embryonic\r\nexplants without the extraembryonic yolk cell, an important
player as a signaling\r\nsource and for morphogenesis during gastrulation, as
a model of ex vivo development.\r\nWe found that dorsal-marginal determinants
are required and sufficient in these\r\nexplants to form and pattern all three
germ layers. However, formation of tissues,\r\nwhich require the highest Nodal-signaling
levels, is variable, demonstrating a\r\ncontribution of extraembryonic tissues
for reaching peak Nodal signaling levels.\r\nBlastoderm explants also undergo
gastrulation-like axis elongation. We found that this\r\nelongation movement shows
hallmarks of oriented mesendoderm cell intercalations\r\ntypically associated
with dorsal tissues in the intact embryo. These are disrupted by\r\nuniform upregulation
of BMP signaling activity and concomitant explant ventralization,\r\nsuggesting
that tight spatial control of BMP signaling is a prerequisite for explant\r\nmorphogenesis.
This control is achieved by Nodal signaling, which is critical for\r\neffectively
downregulating BMP signaling in the mesendoderm, highlighting that Nodal\r\nsignaling
is not only directly required for mesendoderm cell fate specification and\r\nmorphogenesis,
but also by maintaining low levels of BMP signaling at the dorsal side.\r\nCollectively,
we provide insights into the capacity and organization of signaling and\r\nmorphogenetic
domains to recapitulate features of zebrafish gastrulation outside of\r\nthe full
embryonic context."
acknowledged_ssus:
- _id: Bio
- _id: LifeSc
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Alexandra
full_name: Schauer, Alexandra
id: 30A536BA-F248-11E8-B48F-1D18A9856A87
last_name: Schauer
orcid: 0000-0001-7659-9142
citation:
ama: 'Schauer A. Mesendoderm formation in zebrafish gastrulation: The role of extraembryonic
tissues. 2023. doi:10.15479/at:ista:12891'
apa: 'Schauer, A. (2023). Mesendoderm formation in zebrafish gastrulation: The
role of extraembryonic tissues. Institute of Science and Technology Austria.
https://doi.org/10.15479/at:ista:12891'
chicago: 'Schauer, Alexandra. “Mesendoderm Formation in Zebrafish Gastrulation:
The Role of Extraembryonic Tissues.” Institute of Science and Technology Austria,
2023. https://doi.org/10.15479/at:ista:12891.'
ieee: 'A. Schauer, “Mesendoderm formation in zebrafish gastrulation: The role of
extraembryonic tissues,” Institute of Science and Technology Austria, 2023.'
ista: 'Schauer A. 2023. Mesendoderm formation in zebrafish gastrulation: The role
of extraembryonic tissues. Institute of Science and Technology Austria.'
mla: 'Schauer, Alexandra. Mesendoderm Formation in Zebrafish Gastrulation: The
Role of Extraembryonic Tissues. Institute of Science and Technology Austria,
2023, doi:10.15479/at:ista:12891.'
short: 'A. Schauer, Mesendoderm Formation in Zebrafish Gastrulation: The Role of
Extraembryonic Tissues, Institute of Science and Technology Austria, 2023.'
date_created: 2023-05-05T08:48:20Z
date_published: 2023-05-05T00:00:00Z
date_updated: 2023-08-21T06:25:48Z
day: '05'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: GradSch
- _id: CaHe
doi: 10.15479/at:ista:12891
ec_funded: 1
file:
- access_level: closed
checksum: 59b0303dc483f40a96a610a90aab7ee9
content_type: application/pdf
creator: aschauer
date_created: 2023-05-05T13:01:14Z
date_updated: 2023-05-05T13:01:14Z
embargo: 2024-05-05
embargo_to: open_access
file_id: '12907'
file_name: Thesis_Schauer_final.pdf
file_size: 31434230
relation: main_file
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content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
creator: aschauer
date_created: 2023-05-05T13:04:15Z
date_updated: 2023-05-05T13:04:15Z
file_id: '12908'
file_name: Thesis_Schauer_final.docx
file_size: 43809109
relation: source_file
file_date_updated: 2023-05-05T13:04:15Z
has_accepted_license: '1'
language:
- iso: eng
month: '05'
oa_version: Published Version
page: '190'
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
- _id: 26B1E39C-B435-11E9-9278-68D0E5697425
grant_number: '25239'
name: 'Mesendoderm specification in zebrafish: The role of extraembryonic tissues'
publication_identifier:
issn:
- 2663 - 337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '8966'
relation: part_of_dissertation
status: public
- id: '7888'
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: 'Mesendoderm formation in zebrafish gastrulation: The role of extraembryonic
tissues'
type: dissertation
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2023'
...
---
_id: '13175'
abstract:
- lang: eng
text: "About a 100 years ago, we discovered that our universe is inherently noisy,
that is, measuring any physical quantity with a precision beyond a certain point
is not possible because of an omnipresent inherent noise. We call this - the quantum
noise. Certain physical processes allow this quantum noise to get correlated in
conjugate physical variables. These quantum correlations can be used to go beyond
the potential of our inherently noisy universe and obtain a quantum advantage
over the classical applications. \r\n\r\nQuantum noise being inherent also means
that, at the fundamental level, the physical quantities are not well defined and
therefore, objects can stay in multiple states at the same time. For example,
the position of a particle not being well defined means that the particle is in
multiple positions at the same time. About 4 decades ago, we started exploring
the possibility of using objects which can be in multiple states at the same time
to increase the dimensionality in computation. Thus, the field of quantum computing
was born. We discovered that using quantum entanglement, a property closely related
to quantum correlations, can be used to speed up computation of certain problems,
such as factorisation of large numbers, faster than any known classical algorithm.
Thus began the pursuit to make quantum computers a reality. \r\n\r\nTill date,
we have explored quantum control over many physical systems including photons,
spins, atoms, ions and even simple circuits made up of superconducting material.
However, there persists one ubiquitous theme. The more readily a system interacts
with an external field or matter, the more easily we can control it. But this
also means that such a system can easily interact with a noisy environment and
quickly lose its coherence. Consequently, such systems like electron spins need
to be protected from the environment to ensure the longevity of their coherence.
Other systems like nuclear spins are naturally protected as they do not interact
easily with the environment. But, due to the same reason, it is harder to interact
with such systems. \r\n\r\nAfter decades of experimentation with various systems,
we are convinced that no one type of quantum system would be the best for all
the quantum applications. We would need hybrid systems which are all interconnected
- much like the current internet where all sorts of devices can all talk to each
other - but now for quantum devices. A quantum internet. \r\n\r\nOptical photons
are the best contenders to carry information for the quantum internet. They can
carry quantum information cheaply and without much loss - the same reasons which
has made them the backbone of our current internet. Following this direction,
many systems, like trapped ions, have already demonstrated successful quantum
links over a large distances using optical photons. However, some of the most
promising contenders for quantum computing which are based on microwave frequencies
have been left behind. This is because high energy optical photons can adversely
affect fragile low-energy microwave systems. \r\n\r\nIn this thesis, we present
substantial progress on this missing quantum link between microwave and optics
using electrooptical nonlinearities in lithium niobate. The nonlinearities are
enhanced by using resonant cavities for all the involved modes leading to observation
of strong direct coupling between optical and microwave frequencies. With this
strong coupling we are not only able to achieve almost 100\\% internal conversion
efficiency with low added noise, thus presenting a quantum-enabled transducer,
but also we are able to observe novel effects such as cooling of a microwave mode
using optics. The strong coupling regime also leads to direct observation of dynamical
backaction effect between microwave and optical frequencies which are studied
in detail here. Finally, we also report first observation of microwave-optics
entanglement in form of two-mode squeezed vacuum squeezed 0.7dB below vacuum level.
\r\nWith this new bridge between microwave and optics, the microwave-based quantum
technologies can finally be a part of a quantum network which is based on optical
photons - putting us one step closer to a future with quantum internet. "
acknowledged_ssus:
- _id: M-Shop
- _id: SSU
- _id: NanoFab
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Rishabh
full_name: Sahu, Rishabh
id: 47D26E34-F248-11E8-B48F-1D18A9856A87
last_name: Sahu
orcid: 0000-0001-6264-2162
citation:
ama: Sahu R. Cavity quantum electrooptics. 2023. doi:10.15479/at:ista:13175
apa: Sahu, R. (2023). Cavity quantum electrooptics. Institute of Science
and Technology Austria. https://doi.org/10.15479/at:ista:13175
chicago: Sahu, Rishabh. “Cavity Quantum Electrooptics.” Institute of Science and
Technology Austria, 2023. https://doi.org/10.15479/at:ista:13175.
ieee: R. Sahu, “Cavity quantum electrooptics,” Institute of Science and Technology
Austria, 2023.
ista: Sahu R. 2023. Cavity quantum electrooptics. Institute of Science and Technology
Austria.
mla: Sahu, Rishabh. Cavity Quantum Electrooptics. Institute of Science and
Technology Austria, 2023, doi:10.15479/at:ista:13175.
short: R. Sahu, Cavity Quantum Electrooptics, Institute of Science and Technology
Austria, 2023.
date_created: 2023-06-30T08:07:43Z
date_published: 2023-05-05T00:00:00Z
date_updated: 2023-08-24T11:16:35Z
day: '05'
ddc:
- '537'
- '535'
- '539'
degree_awarded: PhD
department:
- _id: GradSch
- _id: JoFi
doi: 10.15479/at:ista:13175
ec_funded: 1
file:
- access_level: open_access
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file_date_updated: 2023-07-06T11:35:15Z
has_accepted_license: '1'
keyword:
- quantum optics
- electrooptics
- quantum networks
- quantum communication
- transduction
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
page: '202'
project:
- _id: 26336814-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '758053'
name: A Fiber Optic Transceiver for Superconducting Qubits
- _id: 9B868D20-BA93-11EA-9121-9846C619BF3A
call_identifier: H2020
grant_number: '899354'
name: Quantum Local Area Networks with Superconducting Qubits
- _id: bdb108fd-d553-11ed-ba76-83dc74a9864f
name: QUANTUM INFORMATION SYSTEMS BEYOND CLASSICAL CAPABILITIES / P5- Integration
of Superconducting Quantum Circuits
publication_identifier:
isbn:
- 978-3-99078-030-5
issn:
- 2663 - 337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '12900'
relation: old_edition
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relation: part_of_dissertation
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relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Johannes M
full_name: Fink, Johannes M
id: 4B591CBA-F248-11E8-B48F-1D18A9856A87
last_name: Fink
orcid: 0000-0001-8112-028X
title: Cavity quantum electrooptics
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short: CC BY-NC-SA (4.0)
type: dissertation
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year: '2023'
...
---
_id: '12900'
abstract:
- lang: eng
text: "About a 100 years ago, we discovered that our universe is inherently noisy,
that is, measuring any physical quantity with a precision beyond a certain point
is not possible because of an omnipresent inherent noise. We call this - the quantum
noise. Certain physical processes allow this quantum noise to get correlated in
conjugate physical variables. These quantum correlations can be used to go beyond
the potential of our inherently noisy universe and obtain a quantum advantage
over the classical applications. \r\n\r\nQuantum noise being inherent also means
that, at the fundamental level, the physical quantities are not well defined and
therefore, objects can stay in multiple states at the same time. For example,
the position of a particle not being well defined means that the particle is in
multiple positions at the same time. About 4 decades ago, we started exploring
the possibility of using objects which can be in multiple states at the same time
to increase the dimensionality in computation. Thus, the field of quantum computing
was born. We discovered that using quantum entanglement, a property closely related
to quantum correlations, can be used to speed up computation of certain problems,
such as factorisation of large numbers, faster than any known classical algorithm.
Thus began the pursuit to make quantum computers a reality. \r\n\r\nTill date,
we have explored quantum control over many physical systems including photons,
spins, atoms, ions and even simple circuits made up of superconducting material.
However, there persists one ubiquitous theme. The more readily a system interacts
with an external field or matter, the more easily we can control it. But this
also means that such a system can easily interact with a noisy environment and
quickly lose its coherence. Consequently, such systems like electron spins need
to be protected from the environment to ensure the longevity of their coherence.
Other systems like nuclear spins are naturally protected as they do not interact
easily with the environment. But, due to the same reason, it is harder to interact
with such systems. \r\n\r\nAfter decades of experimentation with various systems,
we are convinced that no one type of quantum system would be the best for all
the quantum applications. We would need hybrid systems which are all interconnected
- much like the current internet where all sorts of devices can all talk to each
other - but now for quantum devices. A quantum internet. \r\n\r\nOptical photons
are the best contenders to carry information for the quantum internet. They can
carry quantum information cheaply and without much loss - the same reasons which
has made them the backbone of our current internet. Following this direction,
many systems, like trapped ions, have already demonstrated successful quantum
links over a large distances using optical photons. However, some of the most
promising contenders for quantum computing which are based on microwave frequencies
have been left behind. This is because high energy optical photons can adversely
affect fragile low-energy microwave systems. \r\n\r\nIn this thesis, we present
substantial progress on this missing quantum link between microwave and optics
using electrooptical nonlinearities in lithium niobate. The nonlinearities are
enhanced by using resonant cavities for all the involved modes leading to observation
of strong direct coupling between optical and microwave frequencies. With this
strong coupling we are not only able to achieve almost 100\\% internal conversion
efficiency with low added noise, thus presenting a quantum-enabled transducer,
but also we are able to observe novel effects such as cooling of a microwave mode
using optics. The strong coupling regime also leads to direct observation of dynamical
backaction effect between microwave and optical frequencies which are studied
in detail here. Finally, we also report first observation of microwave-optics
entanglement in form of two-mode squeezed vacuum squeezed 0.7dB below vacuum level.
\r\nWith this new bridge between microwave and optics, the microwave-based quantum
technologies can finally be a part of a quantum network which is based on optical
photons - putting us one step closer to a future with quantum internet. "
acknowledged_ssus:
- _id: M-Shop
- _id: SSU
- _id: NanoFab
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Rishabh
full_name: Sahu, Rishabh
id: 47D26E34-F248-11E8-B48F-1D18A9856A87
last_name: Sahu
orcid: 0000-0001-6264-2162
citation:
ama: Sahu R. Cavity quantum electrooptics. 2023. doi:10.15479/at:ista:12900
apa: Sahu, R. (2023). Cavity quantum electrooptics. Institute of Science
and Technology Austria. https://doi.org/10.15479/at:ista:12900
chicago: Sahu, Rishabh. “Cavity Quantum Electrooptics.” Institute of Science and
Technology Austria, 2023. https://doi.org/10.15479/at:ista:12900.
ieee: R. Sahu, “Cavity quantum electrooptics,” Institute of Science and Technology
Austria, 2023.
ista: Sahu R. 2023. Cavity quantum electrooptics. Institute of Science and Technology
Austria.
mla: Sahu, Rishabh. Cavity Quantum Electrooptics. Institute of Science and
Technology Austria, 2023, doi:10.15479/at:ista:12900.
short: R. Sahu, Cavity Quantum Electrooptics, Institute of Science and Technology
Austria, 2023.
date_created: 2023-05-05T11:08:50Z
date_published: 2023-05-05T00:00:00Z
date_updated: 2023-08-24T11:16:35Z
day: '05'
ddc:
- '537'
- '535'
- '539'
degree_awarded: PhD
department:
- _id: GradSch
- _id: JoFi
doi: 10.15479/at:ista:12900
ec_funded: 1
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file_size: 17501990
relation: main_file
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keyword:
- quantum optics
- electrooptics
- quantum networks
- quantum communication
- transduction
language:
- iso: eng
month: '05'
oa_version: Published Version
page: '190'
project:
- _id: 26336814-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '758053'
name: A Fiber Optic Transceiver for Superconducting Qubits
- _id: 9B868D20-BA93-11EA-9121-9846C619BF3A
call_identifier: H2020
grant_number: '899354'
name: Quantum Local Area Networks with Superconducting Qubits
- _id: bdb108fd-d553-11ed-ba76-83dc74a9864f
name: QUANTUM INFORMATION SYSTEMS BEYOND CLASSICAL CAPABILITIES / P5- Integration
of Superconducting Quantum Circuits
publication_identifier:
isbn:
- 978-3-99078-030-5
issn:
- 2663 - 337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '13175'
relation: new_edition
status: public
- id: '10924'
relation: part_of_dissertation
status: public
- id: '9114'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Johannes M
full_name: Fink, Johannes M
id: 4B591CBA-F248-11E8-B48F-1D18A9856A87
last_name: Fink
orcid: 0000-0001-8112-028X
title: Cavity quantum electrooptics
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: '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:
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checksum: 5d2de651ef9449c1b8dc27148ca74777
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date_created: 2023-03-23T16:42:56Z
date_updated: 2023-03-23T16:42:56Z
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creator: pbrighi
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file_name: Thesis_PBrighi.pdf
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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: '13081'
abstract:
- lang: eng
text: During development, tissues undergo changes in size and shape to form functional
organs. Distinct cellular processes such as cell division and cell rearrangements
underlie tissue morphogenesis. Yet how the distinct processes are controlled and
coordinated, and how they contribute to morphogenesis is poorly understood. In
our study, we addressed these questions using the developing mouse neural tube.
This epithelial organ transforms from a flat epithelial sheet to an epithelial
tube while increasing in size and undergoing morpho-gen-mediated patterning. The
extent and mechanism of neural progenitor rearrangement within the developing
mouse neuroepithelium is unknown. To investigate this, we per-formed high resolution
lineage tracing analysis to quantify the extent of epithelial rear-rangement at
different stages of neural tube development. We quantitatively described the relationship
between apical cell size with cell cycle dependent interkinetic nuclear migra-tions
(IKNM) and performed high cellular resolution live imaging of the neuroepithelium
to study the dynamics of junctional remodeling. Furthermore, developed a vertex
model of the neuroepithelium to investigate the quantitative contribution of cell
proliferation, cell differentiation and mechanical properties to the epithelial
rearrangement dynamics and validated the model predictions through functional
experiments. Our analysis revealed that at early developmental stages, the apical
cell area kinetics driven by IKNM induce high lev-els of cell rearrangements in
a regime of high junctional tension and contractility. After E9.5, there is a
sharp decline in the extent of cell rearrangements, suggesting that the epi-thelium
transitions from a fluid-like to a solid-like state. We found that this transition
is regulated by the growth rate of the tissue, rather than by changes in cell-cell
adhesion and contractile forces. Overall, our study provides a quantitative description
of the relationship between tissue growth, cell cycle dynamics, epithelia rearrangements
and the emergent tissue material properties, and novel insights on how epithelial
cell dynamics influences tissue morphogenesis.
acknowledged_ssus:
- _id: Bio
- _id: LifeSc
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Laura
full_name: Bocanegra, Laura
id: 4896F754-F248-11E8-B48F-1D18A9856A87
last_name: Bocanegra
citation:
ama: Bocanegra L. Epithelial dynamics during mouse neural tube development. 2023.
doi:10.15479/at:ista:13081
apa: Bocanegra, L. (2023). Epithelial dynamics during mouse neural tube development.
Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:13081
chicago: Bocanegra, Laura. “Epithelial Dynamics during Mouse Neural Tube Development.”
Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:13081.
ieee: L. Bocanegra, “Epithelial dynamics during mouse neural tube development,”
Institute of Science and Technology Austria, 2023.
ista: Bocanegra L. 2023. Epithelial dynamics during mouse neural tube development.
Institute of Science and Technology Austria.
mla: Bocanegra, Laura. Epithelial Dynamics during Mouse Neural Tube Development.
Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:13081.
short: L. Bocanegra, Epithelial Dynamics during Mouse Neural Tube Development, Institute
of Science and Technology Austria, 2023.
date_created: 2023-05-23T19:10:42Z
date_published: 2023-05-23T00:00:00Z
date_updated: 2023-10-04T11:14:04Z
day: '23'
ddc:
- '570'
degree_awarded: PhD
department:
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- _id: AnKi
doi: 10.15479/at:ista:13081
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issn:
- 2663 - 337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '9349'
relation: part_of_dissertation
status: public
- id: '12837'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Anna
full_name: Kicheva, Anna
id: 3959A2A0-F248-11E8-B48F-1D18A9856A87
last_name: Kicheva
orcid: 0000-0003-4509-4998
title: Epithelial dynamics during mouse neural tube development
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name: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
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short: CC BY-NC-ND (4.0)
type: dissertation
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year: '2023'
...
---
_id: '13331'
abstract:
- lang: eng
text: "The extension of extremal combinatorics to the setting of exterior algebra
is a work\r\nin progress that gained attention recently. In this thesis, we study
the combinatorial structure of exterior algebra by introducing a dictionary that
translates the notions from the set systems into the framework of exterior algebra.
We show both generalizations of celebrated Erdös--Ko--Rado theorem and Hilton--Milner
theorem to the setting of exterior algebra in the simplest non-trivial case of
two-forms.\r\n"
alternative_title:
- ISTA Master's Thesis
article_processing_charge: No
author:
- first_name: Seyda
full_name: Köse, Seyda
id: 8ba3170d-dc85-11ea-9058-c4251c96a6eb
last_name: Köse
citation:
ama: Köse S. Exterior algebra and combinatorics. 2023. doi:10.15479/at:ista:13331
apa: Köse, S. (2023). Exterior algebra and combinatorics. Institute of Science
and Technology Austria. https://doi.org/10.15479/at:ista:13331
chicago: Köse, Seyda. “Exterior Algebra and Combinatorics.” Institute of Science
and Technology Austria, 2023. https://doi.org/10.15479/at:ista:13331.
ieee: S. Köse, “Exterior algebra and combinatorics,” Institute of Science and Technology
Austria, 2023.
ista: Köse S. 2023. Exterior algebra and combinatorics. Institute of Science and
Technology Austria.
mla: Köse, Seyda. Exterior Algebra and Combinatorics. Institute of Science
and Technology Austria, 2023, doi:10.15479/at:ista:13331.
short: S. Köse, Exterior Algebra and Combinatorics, Institute of Science and Technology
Austria, 2023.
date_created: 2023-07-31T10:20:55Z
date_published: 2023-07-31T00:00:00Z
date_updated: 2023-10-04T11:54:56Z
day: '31'
ddc:
- '510'
- '516'
degree_awarded: MS
department:
- _id: GradSch
- _id: UlWa
doi: 10.15479/at:ista:13331
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language:
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month: '07'
oa: 1
oa_version: Published Version
page: '26'
publication_identifier:
issn:
- 2791-4585
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '12680'
relation: part_of_dissertation
status: public
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: Exterior algebra and combinatorics
type: dissertation
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2023'
...
---
_id: '14422'
abstract:
- lang: eng
text: "Animals exhibit a remarkable ability to learn and remember new behaviors,
skills, and associations throughout their lifetime. These capabilities are made
possible thanks to a variety of\r\nchanges in the brain throughout adulthood,
regrouped under the term \"plasticity\". Some cells\r\nin the brain —neurons—
and specifically changes in the connections between neurons, the\r\nsynapses,
were shown to be crucial for the formation, selection, and consolidation of memories\r\nfrom
past experiences. These ongoing changes of synapses across time are called synaptic\r\nplasticity.
Understanding how a myriad of biochemical processes operating at individual\r\nsynapses
can somehow work in concert to give rise to meaningful changes in behavior is
a\r\nfascinating problem and an active area of research.\r\nHowever, the experimental
search for the precise plasticity mechanisms at play in the brain\r\nis daunting,
as it is difficult to control and observe synapses during learning. Theoretical\r\napproaches
have thus been the default method to probe the plasticity-behavior connection.
Such\r\nstudies attempt to extract unifying principles across synapses and model
all observed synaptic\r\nchanges using plasticity rules: equations that govern
the evolution of synaptic strengths across\r\ntime in neuronal network models.
These rules can use many relevant quantities to determine\r\nthe magnitude of
synaptic changes, such as the precise timings of pre- and postsynaptic\r\naction
potentials, the recent neuronal activity levels, the state of neighboring synapses,
etc.\r\nHowever, analytical studies rely heavily on human intuition and are forced
to make simplifying\r\nassumptions about plasticity rules.\r\nIn this thesis,
we aim to assist and augment human intuition in this search for plasticity rules.\r\nWe
explore whether a numerical approach could automatically discover the plasticity
rules\r\nthat elicit desired behaviors in large networks of interconnected neurons.
This approach is\r\ndubbed meta-learning synaptic plasticity: learning plasticity
rules which themselves will make\r\nneuronal networks learn how to solve a desired
task. We first write all the potential plasticity\r\nmechanisms to consider using
a single expression with adjustable parameters. We then optimize\r\nthese plasticity
parameters using evolutionary strategies or Bayesian inference on tasks known\r\nto
involve synaptic plasticity, such as familiarity detection and network stabilization.\r\nWe
show that these automated approaches are powerful tools, able to complement established\r\nanalytical
methods. By comprehensively screening plasticity rules at all synapse types in\r\nrealistic,
spiking neuronal network models, we discover entire sets of degenerate plausible\r\nplasticity
rules that reliably elicit memory-related behaviors. Our approaches allow for
more\r\nrobust experimental predictions, by abstracting out the idiosyncrasies
of individual plasticity\r\nrules, and provide fresh insights on synaptic plasticity
in spiking network models.\r\n"
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Basile J
full_name: Confavreux, Basile J
id: C7610134-B532-11EA-BD9F-F5753DDC885E
last_name: Confavreux
citation:
ama: 'Confavreux BJ. Synapseek: Meta-learning synaptic plasticity rules. 2023. doi:10.15479/at:ista:14422'
apa: 'Confavreux, B. J. (2023). Synapseek: Meta-learning synaptic plasticity
rules. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:14422'
chicago: 'Confavreux, Basile J. “Synapseek: Meta-Learning Synaptic Plasticity Rules.”
Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:14422.'
ieee: 'B. J. Confavreux, “Synapseek: Meta-learning synaptic plasticity rules,” Institute
of Science and Technology Austria, 2023.'
ista: 'Confavreux BJ. 2023. Synapseek: Meta-learning synaptic plasticity rules.
Institute of Science and Technology Austria.'
mla: 'Confavreux, Basile J. Synapseek: Meta-Learning Synaptic Plasticity Rules.
Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:14422.'
short: 'B.J. Confavreux, Synapseek: Meta-Learning Synaptic Plasticity Rules, Institute
of Science and Technology Austria, 2023.'
date_created: 2023-10-12T14:13:25Z
date_published: 2023-10-12T00:00:00Z
date_updated: 2023-10-18T09:20:56Z
day: '12'
ddc:
- '610'
degree_awarded: PhD
department:
- _id: GradSch
- _id: TiVo
doi: 10.15479/at:ista:14422
ec_funded: 1
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creator: cchlebak
date_created: 2023-10-18T07:38:34Z
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relation: source_file
file_date_updated: 2023-10-18T07:56:08Z
has_accepted_license: '1'
language:
- iso: eng
month: '10'
oa_version: Published Version
page: '148'
project:
- _id: 0aacfa84-070f-11eb-9043-d7eb2c709234
call_identifier: H2020
grant_number: '819603'
name: Learning the shape of synaptic plasticity rules for neuronal architectures
and function through machine learning.
publication_identifier:
issn:
- 2663 - 337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '9633'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Tim P
full_name: Vogels, Tim P
id: CB6FF8D2-008F-11EA-8E08-2637E6697425
last_name: Vogels
orcid: 0000-0003-3295-6181
title: 'Synapseek: Meta-learning synaptic plasticity rules'
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short: CC BY-NC-SA (4.0)
type: dissertation
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year: '2023'
...
---
_id: '14374'
abstract:
- lang: eng
text: "Superconductivity has many important applications ranging from levitating
trains over qubits to MRI scanners. The phenomenon is successfully modeled by
Bardeen-Cooper-Schrieffer (BCS) theory. From a mathematical perspective, BCS theory
has been studied extensively for systems without boundary. However, little is
known in the presence of boundaries. With the help of numerical methods physicists
observed that the critical temperature may increase in the presence of a boundary.
The goal of this thesis is to understand the influence of boundaries on the critical
temperature in BCS theory and to give a first rigorous justification of these
observations. On the way, we also study two-body Schrödinger operators on domains
with boundaries and prove additional results for superconductors without boundary.\r\n\r\nBCS
theory is based on a non-linear functional, where the minimizer indicates whether
the system is superconducting or in the normal, non-superconducting state. By
considering the Hessian of the BCS functional at the normal state, one can analyze
whether the normal state is possibly a minimum of the BCS functional and estimate
the critical temperature. The Hessian turns out to be a linear operator resembling
a Schrödinger operator for two interacting particles, but with more complicated
kinetic energy. As a first step, we study the two-body Schrödinger operator in
the presence of boundaries.\r\nFor Neumann boundary conditions, we prove that
the addition of a boundary can create new eigenvalues, which correspond to the
two particles forming a bound state close to the boundary.\r\n\r\nSecond, we need
to understand superconductivity in the translation invariant setting. While in
three dimensions this has been extensively studied, there is no mathematical literature
for the one and two dimensional cases. In dimensions one and two, we compute the
weak coupling asymptotics of the critical temperature and the energy gap in the
translation invariant setting. We also prove that their ratio is independent of
the microscopic details of the model in the weak coupling limit; this property
is referred to as universality.\r\n\r\nIn the third part, we study the critical
temperature of superconductors in the presence of boundaries. We start by considering
the one-dimensional case of a half-line with contact interaction. Then, we generalize
the results to generic interactions and half-spaces in one, two and three dimensions.
Finally, we compare the critical temperature of a quarter space in two dimensions
to the critical temperatures of a half-space and of the full space."
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Barbara
full_name: Roos, Barbara
id: 5DA90512-D80F-11E9-8994-2E2EE6697425
last_name: Roos
orcid: 0000-0002-9071-5880
citation:
ama: Roos B. Boundary superconductivity in BCS theory. 2023. doi:10.15479/at:ista:14374
apa: Roos, B. (2023). Boundary superconductivity in BCS theory. Institute
of Science and Technology Austria. https://doi.org/10.15479/at:ista:14374
chicago: Roos, Barbara. “Boundary Superconductivity in BCS Theory.” Institute of
Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:14374.
ieee: B. Roos, “Boundary superconductivity in BCS theory,” Institute of Science
and Technology Austria, 2023.
ista: Roos B. 2023. Boundary superconductivity in BCS theory. Institute of Science
and Technology Austria.
mla: Roos, Barbara. Boundary Superconductivity in BCS Theory. Institute of
Science and Technology Austria, 2023, doi:10.15479/at:ista:14374.
short: B. Roos, Boundary Superconductivity in BCS Theory, Institute of Science and
Technology Austria, 2023.
date_created: 2023-09-28T14:23:04Z
date_published: 2023-09-30T00:00:00Z
date_updated: 2023-10-27T10:37:30Z
day: '30'
ddc:
- '515'
- '539'
degree_awarded: PhD
department:
- _id: GradSch
- _id: RoSe
doi: 10.15479/at:ista:14374
ec_funded: 1
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has_accepted_license: '1'
language:
- iso: eng
month: '09'
oa: 1
oa_version: Published Version
page: '206'
project:
- _id: 25C6DC12-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '694227'
name: Analysis of quantum many-body systems
- _id: bda63fe5-d553-11ed-ba76-a16e3d2f256b
grant_number: I06427
name: Mathematical Challenges in BCS Theory of Superconductivity
publication_identifier:
issn:
- 2663 - 337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
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- id: '13207'
relation: part_of_dissertation
status: public
- id: '10850'
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: Boundary superconductivity in BCS theory
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...