---
_id: '6392'
abstract:
- lang: eng
text: "The regulation of gene expression is one of the most fundamental processes
in living systems. In recent years, thanks to advances in sequencing technology
and automation, it has become possible to study gene expression quantitatively,
genome-wide and in high-throughput. This leads to the possibility of exploring
changes in gene expression in the context of many external perturbations and their
combinations, and thus of characterising the basic principles governing gene regulation.
In this thesis, I present quantitative experimental approaches to studying transcriptional
and protein level changes in response to combinatorial drug treatment, as well
as a theoretical data-driven approach to analysing thermodynamic principles guiding
transcription of protein coding genes. \r\nIn the first part of this work, I
present a novel methodological framework for quantifying gene expression changes
in drug combinations, termed isogrowth profiling. External perturbations through
small molecule drugs influence the growth rate of the cell, leading to wide-ranging
changes in cellular physiology and gene expression. This confounds the gene expression
changes specifically elicited by the particular drug. Combinatorial perturbations,
owing to the increased stress they exert, influence the growth rate even more
strongly and hence suffer the convolution problem to a greater extent when measuring
gene expression changes. Isogrowth profiling is a way to experimentally abstract
non-specific, growth rate related changes, by performing the measurement using
varying ratios of two drugs at such concentrations that the overall inhibition
rate is constant. Using a robotic setup for automated high-throughput re-dilution
culture of Saccharomyces cerevisiae, the budding yeast, I investigate all pairwise
interactions of four small molecule drugs through sequencing RNA along a growth
isobole. Through principal component analysis, I demonstrate here that isogrowth
profiling can uncover drug-specific as well as drug-interaction-specific gene
expression changes. I show that drug-interaction-specific gene expression changes
can be used for prediction of higher-order drug interactions. I propose a simplified
generalised framework of isogrowth profiling, with few measurements needed for
each drug pair, enabling the broad application of isogrowth profiling to high-throughput
screening of inhibitors of cellular growth and beyond. Such high-throughput screenings
of gene expression changes specific to pairwise drug interactions will be instrumental
for predicting the higher-order interactions of the drugs.\r\n\r\nIn the second
part of this work, I extend isogrowth profiling to single-cell measurements of
gene expression, characterising population heterogeneity in the budding yeast
in response to combinatorial drug perturbation while controlling for non-specific
growth rate effects. Through flow cytometry of strains with protein products fused
to green fluorescent protein, I discover multiple proteins with bi-modally distributed
expression levels in the population in response to drug treatment. I characterize
more closely the effect of an ionic stressor, lithium chloride, and find that
it inhibits the splicing of mRNA, most strongly affecting ribosomal protein transcripts
and leading to a bi-stable behaviour of a small ribosomal subunit protein Rps22B.
Time-lapse microscopy of a microfluidic culture system revealed that the induced
Rps22B heterogeneity leads to preferential survival of Rps22B-low cells after
long starvation, but to preferential proliferation of Rps22B-high cells after
short starvation. Overall, this suggests that yeast cells might use splicing of
ribosomal genes for bet-hedging in fluctuating environments. I give specific examples
of how further exploration of cellular heterogeneity in yeast in response to external
perturbation has the potential to reveal yet-undiscovered gene regulation circuitry.\r\n\r\nIn
the last part of this thesis, a re-analysis of a published sequencing dataset
of nascent elongating transcripts is used to characterise the thermodynamic constraints
for RNA polymerase II (RNAP) elongation. Population-level data on RNAP position
throughout the transcribed genome with single nucleotide resolution are used to
infer the sequence specific thermodynamic determinants of RNAP pausing and backtracking.
This analysis reveals that the basepairing strength of the eight nucleotide-long
RNA:DNA duplex relative to the basepairing strength of the same sequence when
in DNA:DNA duplex, and the change in this quantity during RNA polymerase movement,
is the key determinant of RNAP pausing. This is true for RNAP pausing while elongating,
but also of RNAP pausing while backtracking and of the backtracking length. The
quantitative dependence of RNAP pausing on basepairing energetics is used to infer
the increase in pausing due to transcriptional mismatches, leading to a hypothesis
that pervasive RNA polymerase II pausing is due to basepairing energetics, as
an evolutionary cost for increased RNA polymerase II fidelity.\r\n\r\nThis work
advances our understanding of the general principles governing gene expression,
with the goal of making computational predictions of single-cell gene expression
responses to combinatorial perturbations based on the individual perturbations
possible. This ability would substantially facilitate the design of drug combination
treatments and, in the long term, lead to our increased ability to more generally
design targeted manipulations to any biological system. "
acknowledged_ssus:
- _id: LifeSc
- _id: M-Shop
- _id: Bio
alternative_title:
- IST Austria Thesis
author:
- first_name: Martin
full_name: Lukacisin, Martin
id: 298FFE8C-F248-11E8-B48F-1D18A9856A87
last_name: Lukacisin
orcid: 0000-0001-6549-4177
citation:
ama: Lukacisin M. Quantitative investigation of gene expression principles through
combinatorial drug perturbation and theory. 2019. doi:10.15479/AT:ISTA:6392
apa: Lukacisin, M. (2019). Quantitative investigation of gene expression principles
through combinatorial drug perturbation and theory. IST Austria. https://doi.org/10.15479/AT:ISTA:6392
chicago: Lukacisin, Martin. “Quantitative Investigation of Gene Expression Principles
through Combinatorial Drug Perturbation and Theory.” IST Austria, 2019. https://doi.org/10.15479/AT:ISTA:6392.
ieee: M. Lukacisin, “Quantitative investigation of gene expression principles through
combinatorial drug perturbation and theory,” IST Austria, 2019.
ista: Lukacisin M. 2019. Quantitative investigation of gene expression principles
through combinatorial drug perturbation and theory. IST Austria.
mla: Lukacisin, Martin. Quantitative Investigation of Gene Expression Principles
through Combinatorial Drug Perturbation and Theory. IST Austria, 2019, doi:10.15479/AT:ISTA:6392.
short: M. Lukacisin, Quantitative Investigation of Gene Expression Principles through
Combinatorial Drug Perturbation and Theory, IST Austria, 2019.
date_created: 2019-05-09T19:53:00Z
date_published: 2019-05-09T00:00:00Z
date_updated: 2023-09-22T09:19:41Z
day: '09'
ddc:
- '570'
department:
- _id: ToBo
doi: 10.15479/AT:ISTA:6392
extern: '1'
file:
- access_level: closed
checksum: 829bda074444857c7935171237bb7c0c
content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
creator: mlukacisin
date_created: 2019-05-10T13:51:49Z
date_updated: 2020-07-14T12:47:29Z
embargo_to: open_access
file_id: '6409'
file_name: Thesis_Draft_v3.4Final.docx
file_size: 43740796
relation: hidden
- access_level: open_access
checksum: 56cb5e97f5f8fc41692401b53832d8e0
content_type: application/pdf
creator: mlukacisin
date_created: 2019-05-10T14:13:42Z
date_updated: 2021-02-11T11:17:16Z
embargo: 2020-04-17
file_id: '6410'
file_name: Thesis_Draft_v3.4FinalA.pdf
file_size: 35228388
relation: main_file
file_date_updated: 2021-02-11T11:17:16Z
has_accepted_license: '1'
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
page: '103'
publication_identifier:
isbn:
- 978-3-99078-001-5
issn:
- 2663-337X
publication_status: published
publisher: IST Austria
related_material:
record:
- id: '1029'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Mark Tobias
full_name: Bollenbach, Mark Tobias
id: 3E6DB97A-F248-11E8-B48F-1D18A9856A87
last_name: Bollenbach
orcid: 0000-0003-4398-476X
title: Quantitative investigation of gene expression principles through combinatorial
drug perturbation and theory
type: dissertation
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2019'
...
---
_id: '6435'
abstract:
- lang: eng
text: "Social insect colonies tend to have numerous members which function together
like a single organism in such harmony that the term ``super-organism'' is often
used. In this analogy the reproductive caste is analogous to the primordial germ\r\ncells
of a metazoan, while the sterile worker caste corresponds to somatic cells. The
worker castes, like tissues, are\r\nin charge of all functions of a living being,
besides reproduction. The establishment of new super-organismal units\r\n(i.e.
new colonies) is accomplished by the co-dependent castes. The term oftentimes
goes beyond a metaphor. We invoke it when we speak about the metabolic rate, thermoregulation,
nutrient regulation and gas exchange of a social insect colony. Furthermore, we
assert that the super-organism has an immune system, and benefits from ``social
immunity''.\r\n\r\nSocial immunity was first summoned by evolutionary biologists
to resolve the apparent discrepancy between the expected high frequency of disease
outbreak amongst numerous, closely related tightly-interacting hosts, living in
stable and microbially-rich environments, against the exceptionally scarce epidemic
accounts in natural populations. Social\r\nimmunity comprises a multi-layer assembly
of behaviours which have evolved to effectively keep the pathogenic enemies of
a colony at bay. The field of social immunity has drawn interest, as it becomes
increasingly urgent to stop\r\nthe collapse of pollinator species and curb the
growth of invasive pests. In the past decade, several mechanisms of\r\nsocial
immune responses have been dissected, but many more questions remain open.\r\n\r\nI
present my work in two experimental chapters. In the first, I use invasive garden
ants (*Lasius neglectus*) to study how pathogen load and its distribution among
nestmates affect the grooming response of the group. Any given group of ants will
carry out the same total grooming work, but will direct their grooming effort
towards individuals\r\ncarrying a relatively higher spore load. Contrary to expectation,
the highest risk of transmission does not stem from grooming highly contaminated
ants, but instead, we suggest that the grooming response likely minimizes spore
loss to the environment, reducing contamination from inadvertent pickup from the
substrate.\r\n\r\nThe second is a comparative developmental approach. I follow
black garden ant queens (*Lasius niger*) and their colonies from mating flight,
through hibernation for a year. Colonies which grow fast from the start, have
a lower chance of survival through hibernation, and those which survive grow at
a lower pace later. This is true for colonies of naive\r\nand challenged queens.
Early pathogen exposure of the queens changes colony dynamics in an unexpected
way: colonies from exposed queens are more likely to grow slowly and recover in
numbers only after they survive hibernation.\r\n\r\nIn addition to the two experimental
chapters, this thesis includes a co-authored published review on organisational\r\nimmunity,
where we enlist the experimental evidence and theoretical framework on which this
hypothesis is built,\r\nidentify the caveats and underline how the field is ripe
to overcome them. In a final chapter, I describe my part in\r\ntwo collaborative
efforts, one to develop an image-based tracker, and the second to develop a classifier
for ant\r\nbehaviour."
acknowledged_ssus:
- _id: Bio
- _id: ScienComp
- _id: M-Shop
- _id: LifeSc
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Barbara E
full_name: Casillas Perez, Barbara E
id: 351ED2AA-F248-11E8-B48F-1D18A9856A87
last_name: Casillas Perez
citation:
ama: Casillas Perez BE. Collective defenses of garden ants against a fungal pathogen.
2019. doi:10.15479/AT:ISTA:6435
apa: Casillas Perez, B. E. (2019). Collective defenses of garden ants against
a fungal pathogen. Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:6435
chicago: Casillas Perez, Barbara E. “Collective Defenses of Garden Ants against
a Fungal Pathogen.” Institute of Science and Technology Austria, 2019. https://doi.org/10.15479/AT:ISTA:6435.
ieee: B. E. Casillas Perez, “Collective defenses of garden ants against a fungal
pathogen,” Institute of Science and Technology Austria, 2019.
ista: Casillas Perez BE. 2019. Collective defenses of garden ants against a fungal
pathogen. Institute of Science and Technology Austria.
mla: Casillas Perez, Barbara E. Collective Defenses of Garden Ants against a
Fungal Pathogen. Institute of Science and Technology Austria, 2019, doi:10.15479/AT:ISTA:6435.
short: B.E. Casillas Perez, Collective Defenses of Garden Ants against a Fungal
Pathogen, Institute of Science and Technology Austria, 2019.
date_created: 2019-05-13T08:58:35Z
date_published: 2019-05-07T00:00:00Z
date_updated: 2023-09-07T12:57:04Z
day: '07'
ddc:
- '570'
- '006'
- '578'
- '592'
degree_awarded: PhD
department:
- _id: SyCr
doi: 10.15479/AT:ISTA:6435
ec_funded: 1
file:
- access_level: open_access
checksum: 6daf2d2086111aa8fd3fbc919a3e2833
content_type: application/pdf
creator: casillas
date_created: 2019-05-13T09:16:20Z
date_updated: 2021-02-11T11:17:15Z
embargo: 2020-05-08
file_id: '6438'
file_name: tesisDoctoradoBC.pdf
file_size: 3895187
relation: main_file
- access_level: closed
checksum: 3d221aaff7559a7060230a1ff610594f
content_type: application/zip
creator: casillas
date_created: 2019-05-13T09:16:20Z
date_updated: 2020-07-14T12:47:30Z
embargo_to: open_access
file_id: '6439'
file_name: tesisDoctoradoBC.zip
file_size: 7365118
relation: source_file
file_date_updated: 2021-02-11T11:17:15Z
has_accepted_license: '1'
keyword:
- Social Immunity
- Sanitary care
- Social Insects
- Organisational Immunity
- Colony development
- Multi-target tracking
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
page: '183'
project:
- _id: 2649B4DE-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '771402'
name: Epidemics in ant societies on a chip
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '1999'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Sylvia M
full_name: Cremer, Sylvia M
id: 2F64EC8C-F248-11E8-B48F-1D18A9856A87
last_name: Cremer
orcid: 0000-0002-2193-3868
title: Collective defenses of garden ants against a fungal pathogen
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2019'
...
---
_id: '6269'
abstract:
- lang: eng
text: 'Clathrin-Mediated Endocytosis (CME) is an aspect of cellular trafficking
that is constantly regulated for mediating developmental and physiological responses.
The main aim of my thesis is to decipher the basic mechanisms of CME and post-endocytic
trafficking in the whole multicellular organ systems of Arabidopsis. The first
chapter of my thesis describes the search for new components involved in CME.
Tandem affinity purification was conducted using CLC and its interacting partners
were identified. Amongst the identified proteins were the Auxilin-likes1 and 2
(Axl1/2), putative uncoating factors, for which we made a full functional analysis.
Over-expression of Axl1/2 causes extreme modifications in the dynamics of the
machinery proteins and inhibition of endocytosis altogether. However the loss
of function of the axl1/2 did not present any cellular or physiological phenotype,
meaning Auxilin-likes do not form the major uncoating machinery. The second chapter
of my thesis describes the establishment/utilisation of techniques to capture
the dynamicity and the complexity of CME and post-endocytic trafficking. We have
studied the development of endocytic pits at the PM – specifically, the mode of
membrane remodeling during pit development and the role of actin in it, given
plant cells possess high turgor pressure. Utilizing the improved z-resolution
of TIRF and VAEM techniques, we captured the time-lapse of the endocytic events
at the plasma membrane; and using particle detection software, we quantitatively
analysed all the endocytic trajectories in an unbiased way to obtain the endocytic
rate of the system. This together with the direct analysis of cargo internalisation
from the PM provided an estimate on the endocytic potential of the cell. We also
developed a methodology for ultrastructural analysis of different populations
of Clathrin-Coated Structures (CCSs) in both PM and endomembranes in unroofed
protoplasts. Structural analysis, together with the intensity profile of CCSs
at the PM show that the mode of CCP development at the PM follows ‘Constant curvature
model’; meaning that clathrin polymerisation energy is a major contributing factor
of membrane remodeling. In addition, other analyses clearly show that actin is
not required for membrane remodeling during invagination or any other step of
CCP development, despite the prevalent high turgor pressure. However, actin is
essential in orchestrating the post-endocytic trafficking of CCVs facilitating
the EE formation. We also observed that the uncoating process post-endocytosis
is not immediate; an alternative mechanism of uncoating – Sequential multi-step
process – functions in the cell. Finally we also looked at one of the important
physiological stimuli modulating the process – hormone, auxin. auxin has been
known to influence CME before. We have made a detailed study on the concentration-time
based effect of auxin on the machinery proteins, CCP development, and the specificity
of cargoes endocytosed. To this end, we saw no general effect of auxin on CME
at earlier time points. However, very low concentration of IAA, such as 50nM,
accelerates endocytosis of specifically PIN2 through CME. Such a tight regulatory
control with high specificity to PIN2 could be essential in modulating its polarity. '
acknowledged_ssus:
- _id: Bio
- _id: EM-Fac
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Madhumitha
full_name: Narasimhan, Madhumitha
id: 44BF24D0-F248-11E8-B48F-1D18A9856A87
last_name: Narasimhan
orcid: 0000-0002-8600-0671
citation:
ama: Narasimhan M. Clathrin-Mediated endocytosis, post-endocytic trafficking and
their regulatory controls in plants . 2019. doi:10.15479/at:ista:th1075
apa: Narasimhan, M. (2019). Clathrin-Mediated endocytosis, post-endocytic trafficking
and their regulatory controls in plants . Institute of Science and Technology
Austria. https://doi.org/10.15479/at:ista:th1075
chicago: Narasimhan, Madhumitha. “Clathrin-Mediated Endocytosis, Post-Endocytic
Trafficking and Their Regulatory Controls in Plants .” Institute of Science and
Technology Austria, 2019. https://doi.org/10.15479/at:ista:th1075.
ieee: M. Narasimhan, “Clathrin-Mediated endocytosis, post-endocytic trafficking
and their regulatory controls in plants ,” Institute of Science and Technology
Austria, 2019.
ista: Narasimhan M. 2019. Clathrin-Mediated endocytosis, post-endocytic trafficking
and their regulatory controls in plants . Institute of Science and Technology
Austria.
mla: Narasimhan, Madhumitha. Clathrin-Mediated Endocytosis, Post-Endocytic Trafficking
and Their Regulatory Controls in Plants . Institute of Science and Technology
Austria, 2019, doi:10.15479/at:ista:th1075.
short: M. Narasimhan, Clathrin-Mediated Endocytosis, Post-Endocytic Trafficking
and Their Regulatory Controls in Plants , Institute of Science and Technology
Austria, 2019.
date_created: 2019-04-09T14:37:06Z
date_published: 2019-02-04T00:00:00Z
date_updated: 2023-09-08T11:43:03Z
day: '04'
ddc:
- '575'
degree_awarded: PhD
department:
- _id: JiFr
doi: 10.15479/at:ista:th1075
file:
- access_level: open_access
checksum: c958f27dd752712886e7e2638b847a3c
content_type: video/x-msvideo
creator: dernst
date_created: 2019-04-09T14:35:18Z
date_updated: 2021-02-11T23:30:15Z
embargo: 2020-02-11
file_id: '6270'
file_name: Supplementary_movie_1.avi
file_size: 5402078
relation: main_file
- access_level: open_access
checksum: 8786fdc29c62987c0aad3c866a4d3691
content_type: video/x-msvideo
creator: dernst
date_created: 2019-04-09T14:35:18Z
date_updated: 2021-02-11T23:30:15Z
embargo: 2020-02-11
file_id: '6271'
file_name: 3.7_supplementary_movie_10.avi
file_size: 5927736
relation: main_file
- access_level: open_access
checksum: 25f784c5159d6f4d966b2f9b371ebaf6
content_type: video/x-msvideo
creator: dernst
date_created: 2019-04-09T14:35:18Z
date_updated: 2021-02-11T23:30:15Z
embargo: 2020-02-11
file_id: '6272'
file_name: 3.7_supplementary_movie_9.avi
file_size: 9570210
relation: main_file
- access_level: open_access
checksum: 917069272a7a08d1f38224d5e12765d6
content_type: video/x-msvideo
creator: dernst
date_created: 2019-04-09T14:35:18Z
date_updated: 2021-02-11T23:30:15Z
embargo: 2020-02-11
file_id: '6273'
file_name: 3.7_supplementary_movie_8.avi
file_size: 2827360
relation: main_file
- access_level: open_access
checksum: 81e74f5ca0ad70050504f18192236dc0
content_type: video/x-msvideo
creator: dernst
date_created: 2019-04-09T14:35:18Z
date_updated: 2021-02-11T23:30:15Z
embargo: 2020-02-11
file_id: '6274'
file_name: 3.7_supplementary_movie_7.avi
file_size: 5771410
relation: main_file
- access_level: open_access
checksum: 47eb37b27a2930252713924307ea8c6f
content_type: video/x-msvideo
creator: dernst
date_created: 2019-04-09T14:35:18Z
date_updated: 2021-02-11T23:30:15Z
embargo: 2020-02-11
file_id: '6275'
file_name: 3.7_supplementary_movie_6.avi
file_size: 1113486
relation: main_file
- access_level: open_access
checksum: f68f66721041ce84e331959c9a5779c3
content_type: video/x-msvideo
creator: dernst
date_created: 2019-04-09T14:35:18Z
date_updated: 2021-02-11T23:30:15Z
embargo: 2020-02-11
file_id: '6276'
file_name: 3.7_supplementary_movie_5.avi
file_size: 1057232
relation: main_file
- access_level: open_access
checksum: 67c01cefab51b363c5e214fe4cd671f3
content_type: video/x-msvideo
creator: dernst
date_created: 2019-04-09T14:35:23Z
date_updated: 2021-02-11T23:30:15Z
embargo: 2020-02-11
file_id: '6277'
file_name: 3.7_supplementary_movie_3.avi
file_size: 127472916
relation: main_file
- access_level: open_access
checksum: e5a397edbee05b8821e2b19b3c1a9260
content_type: video/x-msvideo
creator: dernst
date_created: 2019-04-09T14:35:19Z
date_updated: 2021-02-11T23:30:15Z
embargo: 2020-02-11
file_id: '6278'
file_name: 3.7_supplementary_movie_4.avi
file_size: 3181238
relation: main_file
- access_level: open_access
checksum: 32d92b2a9277f956fdb0b42351d07c0b
content_type: video/x-msvideo
creator: dernst
date_created: 2019-04-09T14:35:19Z
date_updated: 2021-02-11T23:30:15Z
embargo: 2020-02-11
file_id: '6279'
file_name: 3.7_supplementary_movie_2.avi
file_size: 5970952
relation: main_file
- access_level: open_access
checksum: efe7001f5d9a8c61e631e12d5f324ade
content_type: video/x-msvideo
creator: dernst
date_created: 2019-04-09T14:35:21Z
date_updated: 2021-02-11T23:30:15Z
embargo: 2020-02-11
file_id: '6280'
file_name: 3.7_Supplementary_movie_1.avi
file_size: 39835236
relation: main_file
- access_level: open_access
checksum: eeb0a5603c6449c5f34eacd5ff0b3a16
content_type: video/x-msvideo
creator: dernst
date_created: 2019-04-09T14:35:21Z
date_updated: 2021-02-11T23:30:15Z
embargo: 2020-02-11
file_id: '6281'
file_name: 2.5_Suppl_Movie_4_AP2A1_TagRFP.avi
file_size: 3696740
relation: main_file
- access_level: open_access
checksum: 8e7c00ef6223bf0e177deb168338af13
content_type: video/x-msvideo
creator: dernst
date_created: 2019-04-09T14:35:21Z
date_updated: 2021-02-11T23:30:15Z
embargo: 2020-02-11
file_id: '6282'
file_name: 2.5_Suppl_Movie_3_TPLATE_GFP.avi
file_size: 6741232
relation: main_file
- access_level: open_access
checksum: 3636006a7cb709a7543d6581e359b28d
content_type: video/x-msvideo
creator: dernst
date_created: 2019-04-09T14:35:22Z
date_updated: 2021-02-11T23:30:15Z
embargo: 2020-02-11
file_id: '6283'
file_name: 2.5_Suppl_Movie_2_CLC_GFP.avi
file_size: 2445946
relation: main_file
- access_level: open_access
checksum: 39ca5519a6e9a38356e7b3704004fea7
content_type: video/x-msvideo
creator: dernst
date_created: 2019-04-09T14:35:22Z
date_updated: 2021-02-11T23:30:15Z
embargo: 2020-02-11
file_id: '6284'
file_name: 2.5_Suppl_Movie_1_CLC_GFPxAxl1_mcherry.avi
file_size: 58594
relation: main_file
- access_level: open_access
checksum: 4fcdaa3a6c645514a3b3205f0f69dc76
content_type: application/pdf
creator: dernst
date_created: 2019-04-09T14:35:33Z
date_updated: 2021-02-11T11:17:15Z
embargo: 2020-02-11
file_id: '6285'
file_name: 2019_Thesis_Narasimhan.pdf
file_size: 10553937
relation: main_file
- access_level: closed
checksum: 268f0b6bad21d5f0d671e5d4b88104a7
content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
creator: dernst
date_created: 2019-04-09T14:35:36Z
date_updated: 2020-07-14T12:47:26Z
embargo_to: open_access
file_id: '6286'
file_name: 2019_Thesis_Narasimhan_source.docx
file_size: 135291990
relation: source_file
file_date_updated: 2021-02-11T23:30:15Z
has_accepted_license: '1'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '02'
oa: 1
oa_version: Published Version
page: '138'
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '412'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Jiří
full_name: Friml, Jiří
id: 4159519E-F248-11E8-B48F-1D18A9856A87
last_name: Friml
orcid: 0000-0002-8302-7596
title: 'Clathrin-Mediated endocytosis, post-endocytic trafficking and their regulatory
controls in plants '
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2019'
...
---
_id: '6947'
abstract:
- lang: eng
text: Lymph nodes are es s ential organs of the immune s ys tem where adaptive
immune responses originate, and consist of various leukocyte populations and a
stromal backbone. Fibroblastic reticular cells (FRCs) are the main stromal cells
and form a sponge-like extracellular matrix network, called conduits , which they thems
elves enwrap and contract. Lymph, containing s oluble antigens , arrive
in lymph nodes via afferent lymphatic vessels that connect to the s ubcaps
ular s inus and conduit network. According to the current paradigm, the conduit network dis
tributes afferent lymph through lymph nodes and thus provides acces
s for immune cells to lymph-borne antigens. An elas tic caps ule s urrounds the organ and confines the
immune cells and FRC network. Lymph nodes are completely packed with lymphocytes and lymphocyte numbers directly dictates the
size of the organ. Although lymphocytes cons tantly enter and leave the lymph node, its s
ize remains remarkedly s table under homeostatic conditions. It is only
partly known how the cellularity and s ize of the lymph node is regulated and how the lymph node is
able to swell in inflammation. The role of the FRC network in lymph node s
welling and trans fer of fluids are inves tigated in this thes is. Furthermore, we s
tudied what trafficking routes are us ed by cancer cells in lymph nodes to form distal
metastases.We examined the role of a mechanical feedback in regulation of lymph node
swelling. Using parallel plate compression and UV-las er cutting experiments we dis
s ected the mechanical force dynamics of the whole lymph node, and individually
for FRCs and the caps ule. Physical forces generated by packed lymphocytes directly affect the tens
ion on the FRC network and capsule, which increases its resistance to swelling. This implies a feedback mechanism between tis
s ue pres s ure and ability of lymphocytes to enter the organ. Following inflammation, the lymph node swells
∼10 fold in two weeks . Yet, what is the role for tens ion on the FRC network and caps
ule, and how are lymphocytes able to enter in conditions that resist
swelling remain open ques tions . We s how that tens ion on the FRC network is important
to limit the swelling rate of the organ so that the FRC network can grow in a coordinated fashion.
This is illustrated by interfering with FRC contractility, which leads to faster
swelling rates and a dis organized FRC network in the inflamed lymph node.
Growth of the FRC network in turn is expected to releas e tens ion on thes
e s tructures and lowers the res is tance to swelling, thereby allowing
more lymphocytes to enter the organ and drive more swelling. Halt of swelling
coincides with a thickening of the caps ule, which forms a thick res
is tant band around the organ and lowers tens ion on the FRC network to form
a new force equilibrium.The FRC and conduit network are further believed to be a privileged s
ite of s oluble information within the lymph node, although many details remain uns
olved. We s how by 3D ultra-recons truction that FRCs and antigen pres
enting cells cover the s urface of conduit s ys tem for more than 99%
and we dis cus s the implications for s oluble information exchangeat the conduit
level.Finally, there is an ongoing debate in the cancer field whether and how
cancer cells in lymph nodes s eed dis tal metas tas es . We s how that cancer cells infus
ed into the lymph node can utilize trafficking routes of immune cells and rapidly migrate to blood vessels.
Once in the blood circulation, these cells are able to form metastases in
distal tissues.
acknowledged_ssus:
- _id: Bio
- _id: PreCl
- _id: EM-Fac
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Frank P
full_name: Assen, Frank P
id: 3A8E7F24-F248-11E8-B48F-1D18A9856A87
last_name: Assen
orcid: 0000-0003-3470-6119
citation:
ama: 'Assen FP. Lymph node mechanics: Deciphering the interplay between stroma contractility,
morphology and lymphocyte trafficking. 2019. doi:10.15479/AT:ISTA:6947'
apa: 'Assen, F. P. (2019). Lymph node mechanics: Deciphering the interplay between
stroma contractility, morphology and lymphocyte trafficking. Institute of
Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:6947'
chicago: 'Assen, Frank P. “Lymph Node Mechanics: Deciphering the Interplay between
Stroma Contractility, Morphology and Lymphocyte Trafficking.” Institute of Science
and Technology Austria, 2019. https://doi.org/10.15479/AT:ISTA:6947.'
ieee: 'F. P. Assen, “Lymph node mechanics: Deciphering the interplay between stroma
contractility, morphology and lymphocyte trafficking,” Institute of Science and
Technology Austria, 2019.'
ista: 'Assen FP. 2019. Lymph node mechanics: Deciphering the interplay between stroma
contractility, morphology and lymphocyte trafficking. Institute of Science and
Technology Austria.'
mla: 'Assen, Frank P. Lymph Node Mechanics: Deciphering the Interplay between
Stroma Contractility, Morphology and Lymphocyte Trafficking. Institute of
Science and Technology Austria, 2019, doi:10.15479/AT:ISTA:6947.'
short: 'F.P. Assen, Lymph Node Mechanics: Deciphering the Interplay between Stroma
Contractility, Morphology and Lymphocyte Trafficking, Institute of Science and
Technology Austria, 2019.'
date_created: 2019-10-14T16:54:52Z
date_published: 2019-10-09T00:00:00Z
date_updated: 2023-09-13T08:50:57Z
day: '9'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: MiSi
doi: 10.15479/AT:ISTA:6947
file:
- access_level: closed
checksum: 53a739752a500f84d0f8ec953cbbd0b6
content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
creator: fassen
date_created: 2019-11-06T12:30:02Z
date_updated: 2020-11-07T23:30:03Z
embargo_to: open_access
file_id: '6990'
file_name: PhDthesis_FrankAssen_revised2.docx
file_size: 214172667
relation: source_file
- access_level: open_access
checksum: 8c156b65d9347bb599623a4b09f15d15
content_type: application/pdf
creator: fassen
date_created: 2019-11-06T12:30:57Z
date_updated: 2020-11-07T23:30:03Z
embargo: 2020-11-06
file_id: '6991'
file_name: PhDthesis_FrankAssen_revised2.pdf
file_size: 83637532
relation: main_file
file_date_updated: 2020-11-07T23:30:03Z
has_accepted_license: '1'
language:
- iso: eng
month: '10'
oa: 1
oa_version: Published Version
page: '142'
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '664'
relation: part_of_dissertation
status: public
- id: '402'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Michael K
full_name: Sixt, Michael K
id: 41E9FBEA-F248-11E8-B48F-1D18A9856A87
last_name: Sixt
orcid: 0000-0002-6620-9179
title: 'Lymph node mechanics: Deciphering the interplay between stroma contractility,
morphology and lymphocyte trafficking'
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2019'
...
---
_id: '6849'
abstract:
- lang: eng
text: 'Brain function is mediated by complex dynamical interactions between excitatory
and inhibitory cell types. The Cholecystokinin-expressing inhibitory cells (CCK-interneurons)
are one of the least studied types, despite being suspected to play important
roles in cognitive processes. We studied the network effects of optogenetic silencing
of CCK-interneurons in the CA1 hippocampal area during exploration and sleep states.
The cell firing pattern in response to light pulses allowed us to classify the
recorded neurons in 5 classes, including disinhibited and non-responsive pyramidal
cell and interneurons, and the inhibited interneurons corresponding to the CCK
group. The light application, which inhibited the activity of CCK interneurons
triggered wider changes in the firing dynamics of cells. We observed rate changes
(i.e. remapping) of pyramidal cells during the exploration session in which the
light was applied relative to the previous control session that was not restricted
neither in time nor space to the light delivery. Also, the disinhibited pyramidal
cells had higher increase in bursting than in single spike firing rate as a result
of CCK silencing. In addition, the firing activity patterns during exploratory
periods were more weakly reactivated in sleep for those periods in which CCK-interneuron
were silenced than in the unaffected periods. Furthermore, light pulses during
sleep disrupted the reactivation of recent waking patterns. Hence, silencing CCK
neurons during exploration suppressed the reactivation of waking firing patterns
in sleep and CCK interneuron activity was also required during sleep for the normal
reactivation of waking patterns. These findings demonstrate the involvement of
CCK cells in reactivation-related memory consolidation. An important part of our
analysis was to test the relationship of the identified CCKinterneurons to brain
oscillations. Our findings showed that these cells exhibited different oscillatory
behaviour during anaesthesia and natural waking and sleep conditions. We showed
that: 1) Contrary to the past studies performed under anaesthesia, the identified
CCKinterneurons fired on the descending portion of the theta phase in waking exploration.
2) CCKinterneuron preferred phases around the trough of gamma oscillations. 3)
Contrary to anaesthesia conditions, the average firing rate of the CCK-interneurons
increased around the peak activity of the sharp-wave ripple (SWR) events in natural
sleep, which is congruent with new reports about their functional connectivity.
We also found that light driven CCK-interneuron silencing altered the dynamics
on the CA1 network oscillatory activity: 1) Pyramidal cells negatively shifted
their preferred theta phases when the light was applied, while interneurons responses
were less consistent. 2) As a population, pyramidal cells negatively shifted their
preferred activity during gamma oscillations, albeit we did not find gamma modulation
differences related to the light application when pyramidal cells were subdivided
into the disinhibited and unaffected groups. 3) During the peak of SWR events,
all but the CCK-interneurons had a reduction in their relative firing rate change
during the light application as compared to the change observed at SWR initiation.
Finally, regarding to the place field activity of the recorded pyramidal neurons,
we showed that the disinhibited pyramidal cells had reduced place field similarity,
coherence and spatial information, but only during the light application. The
mechanisms behind such observed behaviours might involve eCB signalling and plastic
changes in CCK-interneuron synapses. In conclusion, the observed changes related
to the light-mediated silencing of CCKinterneurons have unravelled characteristics
of this interneuron subpopulation that might change the understanding not only
of their particular network interactions, but also of the current theories about
the emergence of certain cognitive processes such as place coding needed for navigation
or hippocampus-dependent memory consolidation. '
acknowledged_ssus:
- _id: Bio
- _id: PreCl
- _id: M-Shop
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Dámaris K
full_name: Rangel Guerrero, Dámaris K
id: 4871BCE6-F248-11E8-B48F-1D18A9856A87
last_name: Rangel Guerrero
orcid: 0000-0002-8602-4374
citation:
ama: Rangel Guerrero DK. The role of CCK-interneurons in regulating hippocampal
network dynamics. 2019. doi:10.15479/AT:ISTA:6849
apa: Rangel Guerrero, D. K. (2019). The role of CCK-interneurons in regulating
hippocampal network dynamics. Institute of Science and Technology Austria.
https://doi.org/10.15479/AT:ISTA:6849
chicago: Rangel Guerrero, Dámaris K. “The Role of CCK-Interneurons in Regulating
Hippocampal Network Dynamics.” Institute of Science and Technology Austria, 2019.
https://doi.org/10.15479/AT:ISTA:6849.
ieee: D. K. Rangel Guerrero, “The role of CCK-interneurons in regulating hippocampal
network dynamics,” Institute of Science and Technology Austria, 2019.
ista: Rangel Guerrero DK. 2019. The role of CCK-interneurons in regulating hippocampal
network dynamics. Institute of Science and Technology Austria.
mla: Rangel Guerrero, Dámaris K. The Role of CCK-Interneurons in Regulating Hippocampal
Network Dynamics. Institute of Science and Technology Austria, 2019, doi:10.15479/AT:ISTA:6849.
short: D.K. Rangel Guerrero, The Role of CCK-Interneurons in Regulating Hippocampal
Network Dynamics, Institute of Science and Technology Austria, 2019.
date_created: 2019-09-06T06:54:16Z
date_published: 2019-09-09T00:00:00Z
date_updated: 2023-09-19T10:01:12Z
day: '09'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: JoCs
doi: 10.15479/AT:ISTA:6849
file:
- access_level: closed
checksum: 244dc4f74dbfc94f414156092298831f
content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
creator: drangel
date_created: 2019-09-09T13:09:45Z
date_updated: 2021-02-10T23:30:09Z
embargo_to: open_access
file_id: '6865'
file_name: Thesis_Damaris_Rangel_source.docx
file_size: 18253100
relation: source_file
- access_level: open_access
checksum: 59c73be40eeaa1c4db24067270151555
content_type: application/pdf
creator: drangel
date_created: 2019-09-09T13:09:52Z
date_updated: 2020-09-11T22:30:04Z
embargo: 2020-09-10
file_id: '6866'
file_name: Thesis_Damaris_Rangel_pdfa.pdf
file_size: 2160109
relation: main_file
request_a_copy: 0
file_date_updated: 2021-02-10T23:30:09Z
has_accepted_license: '1'
language:
- iso: eng
month: '09'
oa: 1
oa_version: Published Version
page: '97'
publication_identifier:
isbn:
- '9783990780039'
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '5914'
relation: part_of_dissertation
status: public
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: The role of CCK-interneurons in regulating hippocampal network dynamics
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2019'
...
---
_id: '7132'
abstract:
- lang: eng
text: "A major challenge in neuroscience research is to dissect the circuits that
orchestrate behavior in health and disease. Proteins from a wide range of non-mammalian
species, such as microbial opsins, have been successfully transplanted to specific
neuronal targets to override their natural communication patterns. The goal of
our work is to manipulate synaptic communication in a manner that closely incorporates
the functional intricacies of synapses by preserving temporal encoding (i.e. the
firing pattern of the presynaptic neuron) and connectivity (i.e. target specific
synapses rather than specific neurons). Our strategy to achieve this goal builds
on the use of non-mammalian transplants to create a synthetic synapse. The mode
of modulation comes from pre-synaptic uptake of a synthetic neurotransmitter (SN)
into synaptic vesicles by means of a genetically targeted transporter selective
for the SN. Upon natural vesicular release, exposure of the SN to the synaptic
cleft will modify the post-synaptic potential through an orthogonal ligand gated
ion channel. To achieve this goal we have functionally characterized a mixed cationic
methionine-gated ion channel from Arabidopsis thaliana, designed a method to functionally
characterize a synthetic transporter in isolated synaptic vesicles without the
need for transgenic animals, identified and extracted multiple prokaryotic uptake
systems that are substrate specific for methionine (Met), and established a primary/cell
line co-culture system that would allow future combinatorial testing of this orthogonal
transmitter-transporter-channel trifecta.\r\nSynthetic synapses will provide a
unique opportunity to manipulate synaptic communication while maintaining the
electrophysiological integrity of the pre-synaptic cell. In this way, information
may be preserved that was generated in upstream circuits and that could be essential
for concerted function and information processing."
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Catherine
full_name: Mckenzie, Catherine
id: 3EEDE19A-F248-11E8-B48F-1D18A9856A87
last_name: Mckenzie
citation:
ama: Mckenzie C. Design and characterization of methods and biological components
to realize synthetic neurotransmission. 2019. doi:10.15479/at:ista:7132
apa: Mckenzie, C. (2019). Design and characterization of methods and biological
components to realize synthetic neurotransmission. Institute of Science and
Technology Austria. https://doi.org/10.15479/at:ista:7132
chicago: Mckenzie, Catherine. “Design and Characterization of Methods and Biological
Components to Realize Synthetic Neurotransmission.” Institute of Science and Technology
Austria, 2019. https://doi.org/10.15479/at:ista:7132.
ieee: C. Mckenzie, “Design and characterization of methods and biological components
to realize synthetic neurotransmission,” Institute of Science and Technology Austria,
2019.
ista: Mckenzie C. 2019. Design and characterization of methods and biological components
to realize synthetic neurotransmission. Institute of Science and Technology Austria.
mla: Mckenzie, Catherine. Design and Characterization of Methods and Biological
Components to Realize Synthetic Neurotransmission. Institute of Science and
Technology Austria, 2019, doi:10.15479/at:ista:7132.
short: C. Mckenzie, Design and Characterization of Methods and Biological Components
to Realize Synthetic Neurotransmission, Institute of Science and Technology Austria,
2019.
date_created: 2019-11-27T09:07:14Z
date_published: 2019-06-27T00:00:00Z
date_updated: 2024-03-28T23:30:21Z
day: '27'
ddc:
- '571'
- '573'
degree_awarded: PhD
department:
- _id: HaJa
doi: 10.15479/at:ista:7132
file:
- access_level: closed
checksum: 34d0fe0f6e0af97b5937205a3e350423
content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
creator: dernst
date_created: 2019-11-27T09:06:10Z
date_updated: 2020-07-14T12:47:50Z
file_id: '7133'
file_name: McKenzie PhD Thesis August 2018 - Corrected Final.docx
file_size: 5054633
relation: source_file
- access_level: open_access
checksum: 140dfb5e3df7edca34f4b6fcc55d876f
content_type: application/pdf
creator: dernst
date_created: 2019-11-27T09:06:10Z
date_updated: 2020-07-14T12:47:50Z
file_id: '7134'
file_name: McKenzie PhD Thesis August 2018 - Corrected Final.pdf
file_size: 3231837
relation: main_file
file_date_updated: 2020-07-14T12:47:50Z
has_accepted_license: '1'
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
page: '95'
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '6266'
relation: old_edition
status: public
status: public
supervisor:
- first_name: Harald L
full_name: Janovjak, Harald L
id: 33BA6C30-F248-11E8-B48F-1D18A9856A87
last_name: Janovjak
orcid: 0000-0002-8023-9315
title: Design and characterization of methods and biological components to realize
synthetic neurotransmission
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2019'
...
---
_id: '6825'
abstract:
- lang: eng
text: "The solving of complex tasks requires the functions of more than one brain
area and their interaction. Whilst spatial navigation and memory is dependent
on the hippocampus, flexible behavior relies on the medial prefrontal cortex (mPFC).
To further examine the roles of the hippocampus and mPFC, we recorded their neural
activity during a task that depends on both of these brain regions.\r\nWith tetrodes,
we recorded the extracellular activity of dorsal hippocampal CA1 (HPC) and mPFC
neurons in Long-Evans rats performing a rule-switching task on the plus-maze.
The plus-maze task had a spatial component since it required navigation along
one of the two start arms and at the maze center a choice between one of the two
goal arms. Which goal contained a reward depended on the rule currently in place.
After an uncued rule change the animal had to abandon the old strategy and switch
to the new rule, testing cognitive flexibility. Investigating the coordination
of activity between the HPC and mPFC allows determination during which task stages
their interaction is required. Additionally, comparing neural activity patterns
in these two brain regions allows delineation of the specialized functions of
the HPC and mPFC in this task. We analyzed neural activity in the HPC and mPFC
in terms of oscillatory interactions, rule coding and replay.\r\nWe found that
theta coherence between the HPC and mPFC is increased at the center and goals
of the maze, both when the rule was stable or has changed. Similar results were
found for locking of HPC and mPFC neurons to HPC theta oscillations. However,
no differences in HPC-mPFC theta coordination were observed between the spatially-
and cue-guided rule. Phase locking of HPC and mPFC neurons to HPC gamma oscillations
was not modulated by\r\nmaze position or rule type. We found that the HPC coded
for the two different rules with cofiring relationships between\r\ncell pairs.
However, we could not find conclusive evidence for rule coding in the mPFC. Spatially-selective
firing in the mPFC generalized between the two start and two goal arms. With Bayesian
positional decoding, we found that the mPFC reactivated non-local positions during
awake immobility periods. Replay of these non-local positions could represent
entire behavioral trajectories resembling trajectory replay of the HPC. Furthermore,
mPFC\r\ntrajectory-replay at the goal positively correlated with rule-switching
performance. \r\nFinally, HPC and mPFC trajectory replay occurred independently
of each other. These results show that the mPFC can replay ordered patterns of
activity during awake immobility, possibly underlying its role in flexible behavior. "
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Karola
full_name: Käfer, Karola
id: 2DAA49AA-F248-11E8-B48F-1D18A9856A87
last_name: Käfer
citation:
ama: Käfer K. The hippocampus and medial prefrontal cortex during flexible behavior.
2019. doi:10.15479/AT:ISTA:6825
apa: Käfer, K. (2019). The hippocampus and medial prefrontal cortex during flexible
behavior. Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:6825
chicago: Käfer, Karola. “The Hippocampus and Medial Prefrontal Cortex during Flexible
Behavior.” Institute of Science and Technology Austria, 2019. https://doi.org/10.15479/AT:ISTA:6825.
ieee: K. Käfer, “The hippocampus and medial prefrontal cortex during flexible behavior,”
Institute of Science and Technology Austria, 2019.
ista: Käfer K. 2019. The hippocampus and medial prefrontal cortex during flexible
behavior. Institute of Science and Technology Austria.
mla: Käfer, Karola. The Hippocampus and Medial Prefrontal Cortex during Flexible
Behavior. Institute of Science and Technology Austria, 2019, doi:10.15479/AT:ISTA:6825.
short: K. Käfer, The Hippocampus and Medial Prefrontal Cortex during Flexible Behavior,
Institute of Science and Technology Austria, 2019.
date_created: 2019-08-21T15:00:57Z
date_published: 2019-08-24T00:00:00Z
date_updated: 2023-09-07T13:01:42Z
day: '24'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: JoCs
doi: 10.15479/AT:ISTA:6825
file:
- access_level: open_access
checksum: 2664420e332a33338568f4f3bfc59287
content_type: application/pdf
creator: kkaefer
date_created: 2019-09-03T08:07:13Z
date_updated: 2020-09-06T22:30:03Z
embargo: 2020-09-05
file_id: '6846'
file_name: Thesis_Kaefer_PDFA.pdf
file_size: 3205202
relation: main_file
request_a_copy: 0
- access_level: closed
checksum: 9a154eab6f07aa590a3d2651dc0d926a
content_type: application/zip
creator: kkaefer
date_created: 2019-09-03T08:07:17Z
date_updated: 2020-09-15T22:30:05Z
embargo_to: open_access
file_id: '6847'
file_name: Thesis_Kaefer.zip
file_size: 2506835
relation: main_file
file_date_updated: 2020-09-15T22:30:05Z
has_accepted_license: '1'
language:
- iso: eng
month: '08'
oa: 1
oa_version: Published Version
page: '89'
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '5949'
relation: part_of_dissertation
status: public
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: The hippocampus and medial prefrontal cortex during flexible behavior
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2019'
...
---
_id: '6546'
abstract:
- lang: eng
text: "Invasive migration plays a crucial role not only during development and homeostasis
but also in pathological states, such as tumor metastasis. Drosophila macrophage
migration into the extended germband is an interesting system to study invasive
migration. It carries similarities to immune cell transmigration and cancer cell
invasion, therefore studying this process could also bring new understanding of
invasion in higher organisms. In our work, we uncover a highly conserved member
of the major facilitator family that plays a role in tissue invasion through regulation
of glycosylation on a subgroup of proteins and/or by aiding the precise timing
of DN-Cadherin downregulation. \r\n\r\nAberrant display of the truncated core1
O-glycan T-antigen is a common feature of human cancer cells that correlates with
metastasis. Here we show that T-antigen in Drosophila melanogaster macrophages
is involved in their developmentally programmed tissue invasion. Higher macrophage
T-antigen levels require an atypical major facilitator superfamily (MFS) member
that we named Minerva which enables macrophage dissemination and invasion. We
characterize for the first time the T and Tn glycoform O-glycoproteome of the
Drosophila melanogaster embryo, and determine that Minerva increases the presence
of T-antigen on proteins in pathways previously linked to cancer, most strongly
on the sulfhydryl oxidase Qsox1 which we show is required for macrophage tissue
entry. Minerva’s vertebrate ortholog, MFSD1, rescues the minerva mutant’s migration
and T-antigen glycosylation defects. We thus identify \r\na key conserved regulator
that orchestrates O-glycosylation on a protein subset to activate \r\na program
governing migration steps important for both development and cancer metastasis.
\r\n"
acknowledged_ssus:
- _id: Bio
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Katarina
full_name: Valosková, Katarina
id: 46F146FC-F248-11E8-B48F-1D18A9856A87
last_name: Valosková
citation:
ama: Valosková K. The role of a highly conserved major facilitator superfamily member
in Drosophila embryonic macrophage migration. 2019. doi:10.15479/AT:ISTA:6546
apa: Valosková, K. (2019). The role of a highly conserved major facilitator superfamily
member in Drosophila embryonic macrophage migration. Institute of Science
and Technology Austria. https://doi.org/10.15479/AT:ISTA:6546
chicago: Valosková, Katarina. “The Role of a Highly Conserved Major Facilitator
Superfamily Member in Drosophila Embryonic Macrophage Migration.” Institute of
Science and Technology Austria, 2019. https://doi.org/10.15479/AT:ISTA:6546.
ieee: K. Valosková, “The role of a highly conserved major facilitator superfamily
member in Drosophila embryonic macrophage migration,” Institute of Science and
Technology Austria, 2019.
ista: Valosková K. 2019. The role of a highly conserved major facilitator superfamily
member in Drosophila embryonic macrophage migration. Institute of Science and
Technology Austria.
mla: Valosková, Katarina. The Role of a Highly Conserved Major Facilitator Superfamily
Member in Drosophila Embryonic Macrophage Migration. Institute of Science
and Technology Austria, 2019, doi:10.15479/AT:ISTA:6546.
short: K. Valosková, The Role of a Highly Conserved Major Facilitator Superfamily
Member in Drosophila Embryonic Macrophage Migration, Institute of Science and
Technology Austria, 2019.
date_created: 2019-06-07T12:49:19Z
date_published: 2019-06-07T00:00:00Z
date_updated: 2023-09-19T10:15:54Z
day: '07'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: DaSi
doi: 10.15479/AT:ISTA:6546
file:
- access_level: closed
checksum: 68949c2d96210b45b981a23e9c9cd93c
content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
creator: khribikova
date_created: 2019-06-07T13:00:04Z
date_updated: 2020-07-14T12:47:33Z
embargo_to: open_access
file_id: '6549'
file_name: Katarina Valoskova_PhD thesis_final version.docx
file_size: 14110626
relation: source_file
- access_level: open_access
checksum: 555329cd76e196c96f5278c480ee2e6e
content_type: application/pdf
creator: khribikova
date_created: 2019-06-07T13:00:08Z
date_updated: 2021-02-11T11:17:14Z
embargo: 2020-06-07
file_id: '6550'
file_name: Katarina Valoskova_PhD thesis_final version.pdf
file_size: 10054156
relation: main_file
file_date_updated: 2021-02-11T11:17:14Z
has_accepted_license: '1'
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
page: '141'
project:
- _id: 253CDE40-B435-11E9-9278-68D0E5697425
grant_number: '24283'
name: Examination of the role of a MFS transporter in the migration of Drosophila
immune cells
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '6187'
relation: part_of_dissertation
status: public
- id: '544'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Daria E
full_name: Siekhaus, Daria E
id: 3D224B9E-F248-11E8-B48F-1D18A9856A87
last_name: Siekhaus
orcid: 0000-0001-8323-8353
title: The role of a highly conserved major facilitator superfamily member in Drosophila
embryonic macrophage migration
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2019'
...
---
_id: '6363'
abstract:
- lang: eng
text: "Distinguishing between similar experiences is achieved by the brain
\ in a process called pattern separation. In the hippocampus, pattern
\ separation reduces the interference of memories and increases the storage
capacity by decorrelating similar inputs patterns of neuronal activity into
\ non-overlapping output firing patterns. Winners-take-all (WTA) mechanism
\ is a theoretical model for pattern separation in which a \"winner\"
\ cell suppresses the activity of the neighboring neurons through feedback
inhibition. However, if the network properties of the dentate gyrus support WTA
as a biologically conceivable model remains unknown. Here, we showed that the
connectivity rules of PV+interneurons and their synaptic properties are optimizedfor
efficient pattern separation. We found using multiple whole-cell in vitrorecordings
that PV+interneurons mainly connect to granule cells (GC) through lateral inhibition,
a form of feedback inhibition in which a GC inhibits other GCs but not
\ itself through the activation of PV+interneurons. Thus, lateral inhibition
between GC–PV+interneurons was ~10 times more abundant than recurrent connections.
Furthermore, the GC–PV+interneuron connectivity was more spatially confined
\ but less abundant than PV+interneurons–GC connectivity, leading to an
\ asymmetrical distribution of excitatory and inhibitory connectivity. Our
network model of the dentate gyrus with incorporated real connectivity rules efficiently
decorrelates neuronal activity patterns using WTA as the primary mechanism.
\ This process relied on lateral inhibition, fast-signaling properties of
\ PV+interneurons and the asymmetrical distribution of excitatory and inhibitory
connectivity. Finally, we found that silencing the activity of PV+interneurons
in vivoleads to acute deficits in discrimination between similar environments,
suggesting that PV+interneuron networks are necessary for behavioral relevant
computations. Our results demonstrate that PV+interneurons possess unique
connectivity and fast signaling properties that confer to the dentate
\ gyrus network properties that allow the emergence of pattern separation. Thus,
our results contribute to the knowledge of how specific forms of network organization
underlie sophisticated types of information processing. \r\n"
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: 'Claudia '
full_name: 'Espinoza Martinez, Claudia '
id: 31FFEE2E-F248-11E8-B48F-1D18A9856A87
last_name: Espinoza Martinez
orcid: 0000-0003-4710-2082
citation:
ama: Espinoza Martinez C. Parvalbumin+ interneurons enable efficient pattern separation
in hippocampal microcircuits. 2019. doi:10.15479/AT:ISTA:6363
apa: Espinoza Martinez, C. (2019). Parvalbumin+ interneurons enable efficient
pattern separation in hippocampal microcircuits. Institute of Science and
Technology Austria. https://doi.org/10.15479/AT:ISTA:6363
chicago: Espinoza Martinez, Claudia . “Parvalbumin+ Interneurons Enable Efficient
Pattern Separation in Hippocampal Microcircuits.” Institute of Science and Technology
Austria, 2019. https://doi.org/10.15479/AT:ISTA:6363.
ieee: C. Espinoza Martinez, “Parvalbumin+ interneurons enable efficient pattern
separation in hippocampal microcircuits,” Institute of Science and Technology
Austria, 2019.
ista: Espinoza Martinez C. 2019. Parvalbumin+ interneurons enable efficient pattern
separation in hippocampal microcircuits. Institute of Science and Technology Austria.
mla: Espinoza Martinez, Claudia. Parvalbumin+ Interneurons Enable Efficient Pattern
Separation in Hippocampal Microcircuits. Institute of Science and Technology
Austria, 2019, doi:10.15479/AT:ISTA:6363.
short: C. Espinoza Martinez, Parvalbumin+ Interneurons Enable Efficient Pattern
Separation in Hippocampal Microcircuits, Institute of Science and Technology Austria,
2019.
date_created: 2019-04-30T11:56:10Z
date_published: 2019-04-30T00:00:00Z
date_updated: 2023-09-15T12:03:48Z
day: '30'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: PeJo
doi: 10.15479/AT:ISTA:6363
file:
- access_level: open_access
checksum: 77c6c05cfe8b58c8abcf1b854375d084
content_type: application/pdf
creator: cespinoza
date_created: 2019-05-07T16:00:39Z
date_updated: 2021-02-11T11:17:15Z
embargo: 2020-05-09
file_id: '6389'
file_name: Espinozathesis_all2.pdf
file_size: 13966891
relation: main_file
- access_level: closed
checksum: f6aa819f127691a2b0fc21c76eb09746
content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
creator: cespinoza
date_created: 2019-05-07T16:00:48Z
date_updated: 2020-07-14T12:47:28Z
embargo_to: open_access
file_id: '6390'
file_name: Espinoza_Thesis.docx
file_size: 11159900
relation: source_file
file_date_updated: 2021-02-11T11:17:15Z
has_accepted_license: '1'
language:
- iso: eng
month: '04'
oa: 1
oa_version: Published Version
page: '140'
publication_identifier:
isbn:
- 978-3-99078-000-8
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '21'
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: Parvalbumin+ interneurons enable efficient pattern separation in hippocampal
microcircuits
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2019'
...
---
_id: '6891'
abstract:
- lang: eng
text: "While cells of mesenchymal or epithelial origin perform their effector functions
in a purely anchorage dependent manner, cells derived from the hematopoietic lineage
are not committed to operate only within a specific niche. Instead, these cells
are able to function autonomously of the molecular composition in a broad range
of tissue compartments. By this means, cells of the hematopoietic lineage retain
the capacity to disseminate into connective tissue and recirculate between organs,
building the foundation for essential processes such as tissue regeneration or
immune surveillance. \r\nCells of the immune system, specifically leukocytes,
are extraordinarily good at performing this task. These cells are able to flexibly
shift their mode of migration between an adhesion-mediated and an adhesion-independent
manner, instantaneously accommodating for any changes in molecular composition
of the external scaffold. The key component driving directed leukocyte migration
is the chemokine receptor 7, which guides the cell along gradients of chemokine
ligand. Therefore, the physical destination of migrating leukocytes is purely
deterministic, i.e. given by global directional cues such as chemokine gradients.
\r\nNevertheless, these cells typically reside in three-dimensional scaffolds
of inhomogeneous complexity, raising the question whether cells are able to locally
discriminate between multiple optional migration routes. Current literature provides
evidence that leukocytes, specifically dendritic cells, do indeed probe their
surrounding by virtue of multiple explorative protrusions. However, it remains
enigmatic how these cells decide which one is the more favorable route to follow
and what are the key players involved in performing this task. Due to the heterogeneous
environment of most tissues, and the vast adaptability of migrating leukocytes,
at this time it is not clear to what extent leukocytes are able to optimize their
migratory strategy by adapting their level of adhesiveness. And, given the fact
that leukocyte migration is characterized by branched cell shapes in combination
with high migration velocities, it is reasonable to assume that these cells require
fine tuned shape maintenance mechanisms that tightly coordinate protrusion and
adhesion dynamics in a spatiotemporal manner. \r\nTherefore, this study aimed
to elucidate how rapidly migrating leukocytes opt for an ideal migratory path
while maintaining a continuous cell shape and balancing adhesive forces to efficiently
navigate through complex microenvironments. \r\nThe results of this study unraveled
a role for the microtubule cytoskeleton in promoting the decision making process
during path finding and for the first time point towards a microtubule-mediated
function in cell shape maintenance of highly ramified cells such as dendritic
cells. Furthermore, we found that migrating low-adhesive leukocytes are able to
instantaneously adapt to increased tensile load by engaging adhesion receptors.
This response was only occurring tangential to the substrate while adhesive properties
in the vertical direction were not increased. As leukocytes are primed for rapid
migration velocities, these results demonstrate that leukocyte integrins are able
to confer a high level of traction forces parallel to the cell membrane along
the direction of migration without wasting energy in gluing the cell to the substrate.
\r\nThus, the data in the here presented thesis provide new insights into the
pivotal role of cytoskeletal dynamics and the mechanisms of force transduction
during leukocyte migration. \r\nThereby the here presented results help to further
define fundamental principles underlying leukocyte migration and open up potential
therapeutic avenues of clinical relevance.\r\n"
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Aglaja
full_name: Kopf, Aglaja
id: 31DAC7B6-F248-11E8-B48F-1D18A9856A87
last_name: Kopf
orcid: 0000-0002-2187-6656
citation:
ama: Kopf A. The implication of cytoskeletal dynamics on leukocyte migration. 2019.
doi:10.15479/AT:ISTA:6891
apa: Kopf, A. (2019). The implication of cytoskeletal dynamics on leukocyte migration.
Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:6891
chicago: Kopf, Aglaja. “The Implication of Cytoskeletal Dynamics on Leukocyte Migration.”
Institute of Science and Technology Austria, 2019. https://doi.org/10.15479/AT:ISTA:6891.
ieee: A. Kopf, “The implication of cytoskeletal dynamics on leukocyte migration,”
Institute of Science and Technology Austria, 2019.
ista: Kopf A. 2019. The implication of cytoskeletal dynamics on leukocyte migration.
Institute of Science and Technology Austria.
mla: Kopf, Aglaja. The Implication of Cytoskeletal Dynamics on Leukocyte Migration.
Institute of Science and Technology Austria, 2019, doi:10.15479/AT:ISTA:6891.
short: A. Kopf, The Implication of Cytoskeletal Dynamics on Leukocyte Migration,
Institute of Science and Technology Austria, 2019.
date_created: 2019-09-19T08:19:44Z
date_published: 2019-07-24T00:00:00Z
date_updated: 2023-10-18T08:49:17Z
day: '24'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: MiSi
doi: 10.15479/AT:ISTA:6891
file:
- access_level: closed
checksum: 00d100d6468e31e583051e0a006b640c
content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
creator: akopf
date_created: 2019-10-15T05:28:42Z
date_updated: 2020-10-17T22:30:03Z
embargo_to: open_access
file_id: '6950'
file_name: Kopf_PhD_Thesis.docx
file_size: 74735267
relation: source_file
- access_level: open_access
checksum: 5d1baa899993ae6ca81aebebe1797000
content_type: application/pdf
creator: akopf
date_created: 2019-10-15T05:28:47Z
date_updated: 2020-10-17T22:30:03Z
embargo: 2020-10-16
file_id: '6951'
file_name: Kopf_PhD_Thesis1.pdf
file_size: 52787224
relation: main_file
file_date_updated: 2020-10-17T22:30:03Z
has_accepted_license: '1'
keyword:
- cell biology
- immunology
- leukocyte
- migration
- microfluidics
language:
- iso: eng
month: '07'
oa: 1
oa_version: Published Version
page: '171'
project:
- _id: 265E2996-B435-11E9-9278-68D0E5697425
call_identifier: FWF
grant_number: W01250-B20
name: Nano-Analytics of Cellular Systems
publication_identifier:
eissn:
- 2663-337X
isbn:
- 978-3-99078-002-2
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
link:
- relation: press_release
url: https://ist.ac.at/en/news/feeling-like-a-cell/
record:
- id: '6328'
relation: part_of_dissertation
status: public
- id: '15'
relation: part_of_dissertation
status: public
- id: '6877'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Michael K
full_name: Sixt, Michael K
id: 41E9FBEA-F248-11E8-B48F-1D18A9856A87
last_name: Sixt
orcid: 0000-0002-6620-9179
title: The implication of cytoskeletal dynamics on leukocyte migration
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2019'
...
---
_id: '6371'
abstract:
- lang: eng
text: "Decades of studies have revealed the mechanisms of gene regulation in molecular
detail. We make use of such well-described regulatory systems to explore how the
molecular mechanisms of protein-protein and protein-DNA interactions shape the
dynamics and evolution of gene regulation. \r\n\r\ni) We uncover how the biophysics
of protein-DNA binding determines the potential of regulatory networks to evolve
and adapt, which can be captured using a simple mathematical model. \r\nii) The
evolution of regulatory connections can lead to a significant amount of crosstalk
between binding proteins. We explore the effect of crosstalk on gene expression
from a target promoter, which seems to be modulated through binding competition
at non-specific DNA sites. \r\niii) We investigate how the very same biophysical
characteristics as in i) can generate significant fitness costs for cells through
global crosstalk, meaning non-specific DNA binding across the genomic background.
\r\niv) Binding competition between proteins at a target promoter is a prevailing
regulatory feature due to the prevalence of co-regulation at bacterial promoters.
However, the dynamics of these systems are not always straightforward to determine
even if the molecular mechanisms of regulation are known. A detailed model of
the biophysical interactions reveals that interference between the regulatory
proteins can constitute a new, generic form of system memory that records the
history of the input signals at the promoter. \r\n\r\nWe demonstrate how the biophysics
of protein-DNA binding can be harnessed to investigate the principles that shape
and ultimately limit cellular gene regulation. These results provide a basis for
studies of higher-level functionality, which arises from the underlying regulation.
\ \r\n"
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Claudia
full_name: Igler, Claudia
id: 46613666-F248-11E8-B48F-1D18A9856A87
last_name: Igler
citation:
ama: Igler C. On the nature of gene regulatory design - The biophysics of transcription
factor binding shapes gene regulation. 2019. doi:10.15479/AT:ISTA:6371
apa: Igler, C. (2019). On the nature of gene regulatory design - The biophysics
of transcription factor binding shapes gene regulation. Institute of Science
and Technology Austria. https://doi.org/10.15479/AT:ISTA:6371
chicago: Igler, Claudia. “On the Nature of Gene Regulatory Design - The Biophysics
of Transcription Factor Binding Shapes Gene Regulation.” Institute of Science
and Technology Austria, 2019. https://doi.org/10.15479/AT:ISTA:6371.
ieee: C. Igler, “On the nature of gene regulatory design - The biophysics of transcription
factor binding shapes gene regulation,” Institute of Science and Technology Austria,
2019.
ista: Igler C. 2019. On the nature of gene regulatory design - The biophysics of
transcription factor binding shapes gene regulation. Institute of Science and
Technology Austria.
mla: Igler, Claudia. On the Nature of Gene Regulatory Design - The Biophysics
of Transcription Factor Binding Shapes Gene Regulation. Institute of Science
and Technology Austria, 2019, doi:10.15479/AT:ISTA:6371.
short: C. Igler, On the Nature of Gene Regulatory Design - The Biophysics of Transcription
Factor Binding Shapes Gene Regulation, Institute of Science and Technology Austria,
2019.
date_created: 2019-05-03T11:55:51Z
date_published: 2019-05-03T00:00:00Z
date_updated: 2024-02-21T13:45:52Z
day: '03'
ddc:
- '576'
- '579'
degree_awarded: PhD
department:
- _id: CaGu
doi: 10.15479/AT:ISTA:6371
file:
- access_level: open_access
checksum: c0085d47c58c9cbcab1b0a783480f6da
content_type: application/pdf
creator: cigler
date_created: 2019-05-03T11:54:52Z
date_updated: 2021-02-11T11:17:13Z
embargo: 2020-05-02
file_id: '6373'
file_name: IglerClaudia_OntheNatureofGeneRegulatoryDesign.pdf
file_size: 12597663
relation: main_file
- access_level: closed
checksum: 2eac954de1c8bbf7e6fb35ed0221ae8c
content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
creator: cigler
date_created: 2019-05-03T11:54:54Z
date_updated: 2020-07-14T12:47:28Z
embargo_to: open_access
file_id: '6374'
file_name: IglerClaudia_OntheNatureofGeneRegulatoryDesign.docx
file_size: 34644426
relation: source_file
file_date_updated: 2021-02-11T11:17:13Z
has_accepted_license: '1'
keyword:
- gene regulation
- biophysics
- transcription factor binding
- bacteria
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
page: '152'
project:
- _id: 251EE76E-B435-11E9-9278-68D0E5697425
grant_number: '24573'
name: Design principles underlying genetic switch architecture (DOC Fellowship)
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '67'
relation: part_of_dissertation
status: public
- id: '5585'
relation: popular_science
status: public
status: public
supervisor:
- first_name: Calin C
full_name: Guet, Calin C
id: 47F8433E-F248-11E8-B48F-1D18A9856A87
last_name: Guet
orcid: 0000-0001-6220-2052
title: On the nature of gene regulatory design - The biophysics of transcription factor
binding shapes gene regulation
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2019'
...
---
_id: '49'
abstract:
- lang: eng
text: Nowadays, quantum computation is receiving more and more attention as an alternative
to the classical way of computing. For realizing a quantum computer, different
devices are investigated as potential quantum bits. In this thesis, the focus
is on Ge hut wires, which turned out to be promising candidates for implementing
hole spin quantum bits. The advantages of Ge as a material system are the low
hyperfine interaction for holes and the strong spin orbit coupling, as well as
the compatibility with the highly developed CMOS processes in industry. In addition,
Ge can also be isotopically purified which is expected to boost the spin coherence
times. The strong spin orbit interaction for holes in Ge on the one hand enables
the full electrical control of the quantum bit and on the other hand should allow
short spin manipulation times. Starting with a bare Si wafer, this work covers
the entire process reaching from growth over the fabrication and characterization
of hut wire devices up to the demonstration of hole spin resonance. From experiments
with single quantum dots, a large g-factor anisotropy between the in-plane and
the out-of-plane direction was found. A comparison to a theoretical model unveiled
the heavy-hole character of the lowest energy states. The second part of the thesis
addresses double quantum dot devices, which were realized by adding two gate electrodes
to a hut wire. In such devices, Pauli spin blockade was observed, which can serve
as a read-out mechanism for spin quantum bits. Applying oscillating electric fields
in spin blockade allowed the demonstration of continuous spin rotations and the
extraction of a lower bound for the spin dephasing time. Despite the strong spin
orbit coupling in Ge, the obtained value for the dephasing time is comparable
to what has been recently reported for holes in Si. All in all, the presented
results point out the high potential of Ge hut wires as a platform for long-lived,
fast and fully electrically tunable hole spin quantum bits.
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Hannes
full_name: Watzinger, Hannes
id: 35DF8E50-F248-11E8-B48F-1D18A9856A87
last_name: Watzinger
citation:
ama: Watzinger H. Ge hut wires - from growth to hole spin resonance. 2018. doi:10.15479/AT:ISTA:th_1033
apa: Watzinger, H. (2018). Ge hut wires - from growth to hole spin resonance.
Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:th_1033
chicago: Watzinger, Hannes. “Ge Hut Wires - from Growth to Hole Spin Resonance.”
Institute of Science and Technology Austria, 2018. https://doi.org/10.15479/AT:ISTA:th_1033.
ieee: H. Watzinger, “Ge hut wires - from growth to hole spin resonance,” Institute
of Science and Technology Austria, 2018.
ista: Watzinger H. 2018. Ge hut wires - from growth to hole spin resonance. Institute
of Science and Technology Austria.
mla: Watzinger, Hannes. Ge Hut Wires - from Growth to Hole Spin Resonance.
Institute of Science and Technology Austria, 2018, doi:10.15479/AT:ISTA:th_1033.
short: H. Watzinger, Ge Hut Wires - from Growth to Hole Spin Resonance, Institute
of Science and Technology Austria, 2018.
date_created: 2018-12-11T11:44:21Z
date_published: 2018-07-30T00:00:00Z
date_updated: 2023-09-07T12:27:43Z
day: '30'
ddc:
- '530'
degree_awarded: PhD
department:
- _id: GeKa
doi: 10.15479/AT:ISTA:th_1033
file:
- access_level: open_access
checksum: b653b5216251f938ddbeafd1de88667c
content_type: application/pdf
creator: dernst
date_created: 2019-04-09T07:13:28Z
date_updated: 2020-07-14T12:46:35Z
file_id: '6249'
file_name: 2018_Thesis_Watzinger.pdf
file_size: 85539748
relation: main_file
- access_level: closed
checksum: 39bcf8de7ac5b1bb516b11ce2f966785
content_type: application/zip
creator: dernst
date_created: 2019-04-09T07:13:27Z
date_updated: 2020-07-14T12:46:35Z
file_id: '6250'
file_name: 2018_Thesis_Watzinger_source.zip
file_size: 21830697
relation: source_file
file_date_updated: 2020-07-14T12:46:35Z
has_accepted_license: '1'
language:
- iso: eng
month: '07'
oa: 1
oa_version: Published Version
page: '77'
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
publist_id: '8005'
pubrep_id: '1033'
status: public
supervisor:
- first_name: Georgios
full_name: Katsaros, Georgios
id: 38DB5788-F248-11E8-B48F-1D18A9856A87
last_name: Katsaros
orcid: 0000-0001-8342-202X
title: Ge hut wires - from growth to hole spin resonance
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: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2018'
...
---
_id: '201'
abstract:
- lang: eng
text: 'We describe arrangements of three-dimensional spheres from a geometrical
and topological point of view. Real data (fitting this setup) often consist of
soft spheres which show certain degree of deformation while strongly packing against
each other. In this context, we answer the following questions: If we model a
soft packing of spheres by hard spheres that are allowed to overlap, can we measure
the volume in the overlapped areas? Can we be more specific about the overlap
volume, i.e. quantify how much volume is there covered exactly twice, three times,
or k times? What would be a good optimization criteria that rule the arrangement
of soft spheres while making a good use of the available space? Fixing a particular
criterion, what would be the optimal sphere configuration? The first result of
this thesis are short formulas for the computation of volumes covered by at least
k of the balls. The formulas exploit information contained in the order-k Voronoi
diagrams and its closely related Level-k complex. The used complexes lead to a
natural generalization into poset diagrams, a theoretical formalism that contains
the order-k and degree-k diagrams as special cases. In parallel, we define different
criteria to determine what could be considered an optimal arrangement from a geometrical
point of view. Fixing a criterion, we find optimal soft packing configurations
in 2D and 3D where the ball centers lie on a lattice. As a last step, we use tools
from computational topology on real physical data, to show the potentials of higher-order
diagrams in the description of melting crystals. The results of the experiments
leaves us with an open window to apply the theories developed in this thesis in
real applications.'
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Mabel
full_name: Iglesias Ham, Mabel
id: 41B58C0C-F248-11E8-B48F-1D18A9856A87
last_name: Iglesias Ham
citation:
ama: Iglesias Ham M. Multiple covers with balls. 2018. doi:10.15479/AT:ISTA:th_1026
apa: Iglesias Ham, M. (2018). Multiple covers with balls. Institute of Science
and Technology Austria. https://doi.org/10.15479/AT:ISTA:th_1026
chicago: Iglesias Ham, Mabel. “Multiple Covers with Balls.” Institute of Science
and Technology Austria, 2018. https://doi.org/10.15479/AT:ISTA:th_1026.
ieee: M. Iglesias Ham, “Multiple covers with balls,” Institute of Science and Technology
Austria, 2018.
ista: Iglesias Ham M. 2018. Multiple covers with balls. Institute of Science and
Technology Austria.
mla: Iglesias Ham, Mabel. Multiple Covers with Balls. Institute of Science
and Technology Austria, 2018, doi:10.15479/AT:ISTA:th_1026.
short: M. Iglesias Ham, Multiple Covers with Balls, Institute of Science and Technology
Austria, 2018.
date_created: 2018-12-11T11:45:10Z
date_published: 2018-06-11T00:00:00Z
date_updated: 2023-09-07T12:25:32Z
day: '11'
ddc:
- '514'
- '516'
degree_awarded: PhD
department:
- _id: HeEd
doi: 10.15479/AT:ISTA:th_1026
file:
- access_level: closed
checksum: dd699303623e96d1478a6ae07210dd05
content_type: application/zip
creator: kschuh
date_created: 2019-02-05T07:43:31Z
date_updated: 2020-07-14T12:45:24Z
file_id: '5918'
file_name: IST-2018-1025-v2+5_ist-thesis-iglesias-11June2018(1).zip
file_size: 11827713
relation: source_file
- access_level: open_access
checksum: ba163849a190d2b41d66fef0e4983294
content_type: application/pdf
creator: kschuh
date_created: 2019-02-05T07:43:45Z
date_updated: 2020-07-14T12:45:24Z
file_id: '5919'
file_name: IST-2018-1025-v2+4_ThesisIglesiasFinal11June2018.pdf
file_size: 4783846
relation: main_file
file_date_updated: 2020-07-14T12:45:24Z
has_accepted_license: '1'
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
page: '171'
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
publist_id: '7712'
pubrep_id: '1026'
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: Multiple covers with balls
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2018'
...
---
_id: '68'
abstract:
- lang: eng
text: The most common assumption made in statistical learning theory is the assumption
of the independent and identically distributed (i.i.d.) data. While being very
convenient mathematically, it is often very clearly violated in practice. This
disparity between the machine learning theory and applications underlies a growing
demand in the development of algorithms that learn from dependent data and theory
that can provide generalization guarantees similar to the independent situations.
This thesis is dedicated to two variants of dependencies that can arise in practice.
One is a dependence on the level of samples in a single learning task. Another
dependency type arises in the multi-task setting when the tasks are dependent
on each other even though the data for them can be i.i.d. In both cases we model
the data (samples or tasks) as stochastic processes and introduce new algorithms
for both settings that take into account and exploit the resulting dependencies.
We prove the theoretical guarantees on the performance of the introduced algorithms
under different evaluation criteria and, in addition, we compliment the theoretical
study by the empirical one, where we evaluate some of the algorithms on two real
world datasets to highlight their practical applicability.
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Alexander
full_name: Zimin, Alexander
id: 37099E9C-F248-11E8-B48F-1D18A9856A87
last_name: Zimin
citation:
ama: Zimin A. Learning from dependent data. 2018. doi:10.15479/AT:ISTA:TH1048
apa: Zimin, A. (2018). Learning from dependent data. Institute of Science
and Technology Austria. https://doi.org/10.15479/AT:ISTA:TH1048
chicago: Zimin, Alexander. “Learning from Dependent Data.” Institute of Science
and Technology Austria, 2018. https://doi.org/10.15479/AT:ISTA:TH1048.
ieee: A. Zimin, “Learning from dependent data,” Institute of Science and Technology
Austria, 2018.
ista: Zimin A. 2018. Learning from dependent data. Institute of Science and Technology
Austria.
mla: Zimin, Alexander. Learning from Dependent Data. Institute of Science
and Technology Austria, 2018, doi:10.15479/AT:ISTA:TH1048.
short: A. Zimin, Learning from Dependent Data, Institute of Science and Technology
Austria, 2018.
date_created: 2018-12-11T11:44:27Z
date_published: 2018-09-01T00:00:00Z
date_updated: 2023-09-07T12:29:07Z
day: '01'
ddc:
- '004'
- '519'
degree_awarded: PhD
department:
- _id: ChLa
doi: 10.15479/AT:ISTA:TH1048
ec_funded: 1
file:
- access_level: open_access
checksum: e849dd40a915e4d6c5572b51b517f098
content_type: application/pdf
creator: dernst
date_created: 2019-04-09T07:32:47Z
date_updated: 2020-07-14T12:47:40Z
file_id: '6253'
file_name: 2018_Thesis_Zimin.pdf
file_size: 1036137
relation: main_file
- access_level: closed
checksum: da092153cec55c97461bd53c45c5d139
content_type: application/zip
creator: dernst
date_created: 2019-04-09T07:32:47Z
date_updated: 2020-07-14T12:47:40Z
file_id: '6254'
file_name: 2018_Thesis_Zimin_Source.zip
file_size: 637490
relation: source_file
file_date_updated: 2020-07-14T12:47:40Z
has_accepted_license: '1'
language:
- iso: eng
month: '09'
oa: 1
oa_version: Published Version
page: '92'
project:
- _id: 2532554C-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '308036'
name: Lifelong Learning of Visual Scene Understanding
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
publist_id: '7986'
pubrep_id: '1048'
status: public
supervisor:
- first_name: Christoph
full_name: Lampert, Christoph
id: 40C20FD2-F248-11E8-B48F-1D18A9856A87
last_name: Lampert
orcid: 0000-0001-8622-7887
title: Learning from dependent data
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2018'
...
---
_id: '83'
abstract:
- lang: eng
text: "A proof system is a protocol between a prover and a verifier over a common
input in which an honest prover convinces the verifier of the validity of true
statements. Motivated by the success of decentralized cryptocurrencies, exemplified
by Bitcoin, the focus of this thesis will be on proof systems which found applications
in some sustainable alternatives to Bitcoin, such as the Spacemint and Chia cryptocurrencies.
In particular, we focus on proofs of space and proofs of sequential work.\r\nProofs
of space (PoSpace) were suggested as more ecological, economical, and egalitarian
alternative to the energy-wasteful proof-of-work mining of Bitcoin. However, the
state-of-the-art constructions of PoSpace are based on sophisticated graph pebbling
lower bounds, and are therefore complex. Moreover, when these PoSpace are used
in cryptocurrencies like Spacemint, miners can only start mining after ensuring
that a commitment to their space is already added in a special transaction to
the blockchain. Proofs of sequential work (PoSW) are proof systems in which a
prover, upon receiving a statement x and a time parameter T, computes a proof
which convinces the verifier that T time units had passed since x was received.
Whereas Spacemint assumes synchrony to retain some interesting Bitcoin dynamics,
Chia requires PoSW with unique proofs, i.e., PoSW in which it is hard to come
up with more than one accepting proof for any true statement. In this thesis we
construct simple and practically-efficient PoSpace and PoSW. When using our PoSpace
in cryptocurrencies, miners can start mining on the fly, like in Bitcoin, and
unlike current constructions of PoSW, which either achieve efficient verification
of sequential work, or faster-than-recomputing verification of correctness of
proofs, but not both at the same time, ours achieve the best of these two worlds."
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Hamza M
full_name: Abusalah, Hamza M
id: 40297222-F248-11E8-B48F-1D18A9856A87
last_name: Abusalah
citation:
ama: Abusalah HM. Proof systems for sustainable decentralized cryptocurrencies.
2018. doi:10.15479/AT:ISTA:TH_1046
apa: Abusalah, H. M. (2018). Proof systems for sustainable decentralized cryptocurrencies.
Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:TH_1046
chicago: Abusalah, Hamza M. “Proof Systems for Sustainable Decentralized Cryptocurrencies.”
Institute of Science and Technology Austria, 2018. https://doi.org/10.15479/AT:ISTA:TH_1046.
ieee: H. M. Abusalah, “Proof systems for sustainable decentralized cryptocurrencies,”
Institute of Science and Technology Austria, 2018.
ista: Abusalah HM. 2018. Proof systems for sustainable decentralized cryptocurrencies.
Institute of Science and Technology Austria.
mla: Abusalah, Hamza M. Proof Systems for Sustainable Decentralized Cryptocurrencies.
Institute of Science and Technology Austria, 2018, doi:10.15479/AT:ISTA:TH_1046.
short: H.M. Abusalah, Proof Systems for Sustainable Decentralized Cryptocurrencies,
Institute of Science and Technology Austria, 2018.
date_created: 2018-12-11T11:44:32Z
date_published: 2018-09-05T00:00:00Z
date_updated: 2023-09-07T12:30:23Z
day: '05'
ddc:
- '004'
degree_awarded: PhD
department:
- _id: KrPi
doi: 10.15479/AT:ISTA:TH_1046
ec_funded: 1
file:
- access_level: open_access
checksum: c4b5f7d111755d1396787f41886fc674
content_type: application/pdf
creator: dernst
date_created: 2019-04-09T06:43:41Z
date_updated: 2020-07-14T12:48:11Z
file_id: '6245'
file_name: 2018_Thesis_Abusalah.pdf
file_size: 876241
relation: main_file
- access_level: closed
checksum: 0f382ac56b471c48fd907d63eb87dafe
content_type: application/x-gzip
creator: dernst
date_created: 2019-04-09T06:43:41Z
date_updated: 2020-07-14T12:48:11Z
file_id: '6246'
file_name: 2018_Thesis_Abusalah_source.tar.gz
file_size: 2029190
relation: source_file
file_date_updated: 2020-07-14T12:48:11Z
has_accepted_license: '1'
language:
- iso: eng
month: '09'
oa: 1
oa_version: Published Version
page: '59'
project:
- _id: 258C570E-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '259668'
name: Provable Security for Physical Cryptography
- _id: 258AA5B2-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '682815'
name: Teaching Old Crypto New Tricks
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
publist_id: '7971'
pubrep_id: '1046'
related_material:
record:
- id: '1229'
relation: part_of_dissertation
status: public
- id: '1235'
relation: part_of_dissertation
status: public
- id: '1236'
relation: part_of_dissertation
status: public
- id: '559'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Krzysztof Z
full_name: Pietrzak, Krzysztof Z
id: 3E04A7AA-F248-11E8-B48F-1D18A9856A87
last_name: Pietrzak
orcid: 0000-0002-9139-1654
title: Proof systems for sustainable decentralized cryptocurrencies
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2018'
...
---
_id: '197'
abstract:
- lang: eng
text: Modern computer vision systems heavily rely on statistical machine learning
models, which typically require large amounts of labeled data to be learned reliably.
Moreover, very recently computer vision research widely adopted techniques for
representation learning, which further increase the demand for labeled data. However,
for many important practical problems there is relatively small amount of labeled
data available, so it is problematic to leverage full potential of the representation
learning methods. One way to overcome this obstacle is to invest substantial resources
into producing large labelled datasets. Unfortunately, this can be prohibitively
expensive in practice. In this thesis we focus on the alternative way of tackling
the aforementioned issue. We concentrate on methods, which make use of weakly-labeled
or even unlabeled data. Specifically, the first half of the thesis is dedicated
to the semantic image segmentation task. We develop a technique, which achieves
competitive segmentation performance and only requires annotations in a form of
global image-level labels instead of dense segmentation masks. Subsequently, we
present a new methodology, which further improves segmentation performance by
leveraging tiny additional feedback from a human annotator. By using our methods
practitioners can greatly reduce the amount of data annotation effort, which is
required to learn modern image segmentation models. In the second half of the
thesis we focus on methods for learning from unlabeled visual data. We study a
family of autoregressive models for modeling structure of natural images and discuss
potential applications of these models. Moreover, we conduct in-depth study of
one of these applications, where we develop the state-of-the-art model for the
probabilistic image colorization task.
acknowledgement: I also gratefully acknowledge the support of NVIDIA Corporation with
the donation of the GPUs used for this research.
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Alexander
full_name: Kolesnikov, Alexander
id: 2D157DB6-F248-11E8-B48F-1D18A9856A87
last_name: Kolesnikov
citation:
ama: Kolesnikov A. Weakly-Supervised Segmentation and Unsupervised Modeling of Natural
Images. 2018. doi:10.15479/AT:ISTA:th_1021
apa: Kolesnikov, A. (2018). Weakly-Supervised Segmentation and Unsupervised Modeling
of Natural Images. Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:th_1021
chicago: Kolesnikov, Alexander. “Weakly-Supervised Segmentation and Unsupervised
Modeling of Natural Images.” Institute of Science and Technology Austria, 2018.
https://doi.org/10.15479/AT:ISTA:th_1021.
ieee: A. Kolesnikov, “Weakly-Supervised Segmentation and Unsupervised Modeling of
Natural Images,” Institute of Science and Technology Austria, 2018.
ista: Kolesnikov A. 2018. Weakly-Supervised Segmentation and Unsupervised Modeling
of Natural Images. Institute of Science and Technology Austria.
mla: Kolesnikov, Alexander. Weakly-Supervised Segmentation and Unsupervised Modeling
of Natural Images. Institute of Science and Technology Austria, 2018, doi:10.15479/AT:ISTA:th_1021.
short: A. Kolesnikov, Weakly-Supervised Segmentation and Unsupervised Modeling of
Natural Images, Institute of Science and Technology Austria, 2018.
date_created: 2018-12-11T11:45:09Z
date_published: 2018-05-25T00:00:00Z
date_updated: 2023-09-07T12:51:46Z
day: '25'
ddc:
- '004'
degree_awarded: PhD
department:
- _id: ChLa
doi: 10.15479/AT:ISTA:th_1021
ec_funded: 1
file:
- access_level: open_access
checksum: bc678e02468d8ebc39dc7267dfb0a1c4
content_type: application/pdf
creator: system
date_created: 2018-12-12T10:14:57Z
date_updated: 2020-07-14T12:45:22Z
file_id: '5113'
file_name: IST-2018-1021-v1+1_thesis-unsigned-pdfa.pdf
file_size: 12918758
relation: main_file
- access_level: closed
checksum: bc66973b086da5a043f1162dcfb1fde4
content_type: application/zip
creator: dernst
date_created: 2019-04-05T09:34:49Z
date_updated: 2020-07-14T12:45:22Z
file_id: '6225'
file_name: 2018_Thesis_Kolesnikov_source.zip
file_size: 55973760
relation: source_file
file_date_updated: 2020-07-14T12:45:22Z
has_accepted_license: '1'
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
page: '113'
project:
- _id: 2532554C-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '308036'
name: Lifelong Learning of Visual Scene Understanding
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
publist_id: '7718'
pubrep_id: '1021'
status: public
supervisor:
- first_name: Christoph
full_name: Lampert, Christoph
id: 40C20FD2-F248-11E8-B48F-1D18A9856A87
last_name: Lampert
orcid: 0000-0001-8622-7887
title: Weakly-Supervised Segmentation and Unsupervised Modeling of Natural Images
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2018'
...
---
_id: '200'
abstract:
- lang: eng
text: This thesis is concerned with the inference of current population structure
based on geo-referenced genetic data. The underlying idea is that population structure
affects its spatial genetic structure. Therefore, genotype information can be
utilized to estimate important demographic parameters such as migration rates.
These indirect estimates of population structure have become very attractive,
as genotype data is now widely available. However, there also has been much concern
about these approaches. Importantly, genetic structure can be influenced by many
complex patterns, which often cannot be disentangled. Moreover, many methods merely
fit heuristic patterns of genetic structure, and do not build upon population
genetics theory. Here, I describe two novel inference methods that address these
shortcomings. In Chapter 2, I introduce an inference scheme based on a new type
of signal, identity by descent (IBD) blocks. Recently, it has become feasible
to detect such long blocks of genome shared between pairs of samples. These blocks
are direct traces of recent coalescence events. As such, they contain ample signal
for inferring recent demography. I examine sharing of IBD blocks in two-dimensional
populations with local migration. Using a diffusion approximation, I derive formulas
for an isolation by distance pattern of long IBD blocks and show that sharing
of long IBD blocks approaches rapid exponential decay for growing sample distance.
I describe an inference scheme based on these results. It can robustly estimate
the dispersal rate and population density, which is demonstrated on simulated
data. I also show an application to estimate mean migration and the rate of recent
population growth within Eastern Europe. Chapter 3 is about a novel method to
estimate barriers to gene flow in a two dimensional population. This inference
scheme utilizes geographically localized allele frequency fluctuations - a classical
isolation by distance signal. The strength of these local fluctuations increases
on average next to a barrier, and there is less correlation across it. I again
use a framework of diffusion of ancestral lineages to model this effect, and provide
an efficient numerical implementation to fit the results to geo-referenced biallelic
SNP data. This inference scheme is able to robustly estimate strong barriers to
gene flow, as tests on simulated data confirm.
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Harald
full_name: Ringbauer, Harald
id: 417FCFF4-F248-11E8-B48F-1D18A9856A87
last_name: Ringbauer
orcid: 0000-0002-4884-9682
citation:
ama: Ringbauer H. Inferring recent demography from spatial genetic structure. 2018.
doi:10.15479/AT:ISTA:th_963
apa: Ringbauer, H. (2018). Inferring recent demography from spatial genetic structure.
Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:th_963
chicago: Ringbauer, Harald. “Inferring Recent Demography from Spatial Genetic Structure.”
Institute of Science and Technology Austria, 2018. https://doi.org/10.15479/AT:ISTA:th_963.
ieee: H. Ringbauer, “Inferring recent demography from spatial genetic structure,”
Institute of Science and Technology Austria, 2018.
ista: Ringbauer H. 2018. Inferring recent demography from spatial genetic structure.
Institute of Science and Technology Austria.
mla: Ringbauer, Harald. Inferring Recent Demography from Spatial Genetic Structure.
Institute of Science and Technology Austria, 2018, doi:10.15479/AT:ISTA:th_963.
short: H. Ringbauer, Inferring Recent Demography from Spatial Genetic Structure,
Institute of Science and Technology Austria, 2018.
date_created: 2018-12-11T11:45:10Z
date_published: 2018-02-21T00:00:00Z
date_updated: 2023-09-20T12:00:56Z
day: '21'
ddc:
- '576'
degree_awarded: PhD
department:
- _id: NiBa
doi: 10.15479/AT:ISTA:th_963
file:
- access_level: open_access
checksum: 8cc534d2b528ae017acf80874cce48c9
content_type: application/pdf
creator: system
date_created: 2018-12-12T10:14:55Z
date_updated: 2020-07-14T12:45:23Z
file_id: '5111'
file_name: IST-2018-963-v1+1_thesis.pdf
file_size: 5792935
relation: main_file
- access_level: closed
checksum: 6af18d7e5a7e2728ceda2f41ee24f628
content_type: application/zip
creator: dernst
date_created: 2019-04-05T09:30:12Z
date_updated: 2020-07-14T12:45:23Z
file_id: '6224'
file_name: 2018_thesis_ringbauer_source.zip
file_size: 113365
relation: source_file
file_date_updated: 2020-07-14T12:45:23Z
has_accepted_license: '1'
language:
- iso: eng
license: https://creativecommons.org/licenses/by-nc/4.0/
month: '02'
oa: 1
oa_version: Published Version
page: '146'
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
publist_id: '7713'
pubrep_id: '963'
related_material:
record:
- id: '563'
relation: part_of_dissertation
status: public
- id: '1074'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Nicholas H
full_name: Barton, Nicholas H
id: 4880FE40-F248-11E8-B48F-1D18A9856A87
last_name: Barton
orcid: 0000-0002-8548-5240
title: Inferring recent demography from spatial genetic structure
tmp:
image: /images/cc_by_nc.png
legal_code_url: https://creativecommons.org/licenses/by-nc/4.0/legalcode
name: Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
short: CC BY-NC (4.0)
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2018'
...
---
_id: '418'
abstract:
- lang: eng
text: "The aim of this thesis was the development of new strategies for optical
and optogenetic control of proliferative and pro-survival signaling, and characterizing
them from the molecular mechanism up to cellular effects. These new light-based
methods have unique features, such as red light as an activator, or the avoidance
of gene delivery, which enable to overcome current limitations, such as light
delivery to target tissues and feasibility as therapeutic approach. A special
focus was placed on implementing these new light-based approaches in pancreatic
β-cells, as β-cells are the key players in diabetes and especially their loss
in number negatively affects disease progression. Currently no treatment options
are available to compensate the lack of functional β-cells in diabetic patients.\r\nIn
a first approach, red-light-activated growth factor receptors, in particular receptor
tyrosine kinases were engineered and characterized. Receptor activation with light
allows spatio-temporal control compared to ligand-based activation, and especially
red light exhibits deeper tissue penetration than other wavelengths of the visible
spectrum. Red-light-activated receptor tyrosine kinases robustly activated major
growth factor related signaling pathways with a high temporal resolution. Moreover,
the remote activation of the proliferative MAPK/Erk pathway by red-light-activated
receptor tyrosine kinases in a pancreatic β-cell line was also achieved, through
one centimeter thick mouse tissue. Although red-light-activated receptor tyrosine
kinases are particularly attractive for applications in animal models due to the
deep tissue penetration of red light, a drawback, especially with regard to translation
into humans, is the requirement of gene therapy.\r\nIn a second approach an endogenous
light-sensitive mechanism was identified and its potential to promote proliferative
and pro-survival signals was explored, towards light-based tissue regeneration
without the need for gene transfer. Blue-green light illumination was found to
be sufficient for the activation of proliferation and survival promoting signaling
pathways in primary pancreatic murine and human islets. Blue-green light also
led to an increase in proliferation of primary islet cells, an effect which was
shown to be mostly β-cell specific in human islets. Moreover, it was demonstrated
that this approach of pancreatic β-cell expansion did not have any negative effect
on the β-cell function, in particular on their insulin secretion capacity. In
contrast, a trend for enhanced insulin secretion under high glucose conditions
after illumination was detected. In order to unravel the detailed characteristics
of this endogenous light-sensitive mechanism, the precise light requirements were
determined. In addition, the expression of light sensing proteins, OPN3 and rhodopsin,
was detected. The observed effects were found to be independent of handling effects
such as temperature differences and cytochrome c oxidase dependent ATP increase,
but they were found to be enhanced through the knockout of OPN3. The exact mechanism
of how islets cells sense light and the identity of the photoreceptor remains
unknown.\r\nSummarized two new light-based systems with unique features were established
that enable the activation of proliferative and pro-survival signaling pathways.
While red-light-activated receptor tyrosine kinases open a new avenue for optogenetics
research, by allowing non-invasive control of signaling in vivo, the identified
endogenous light-sensitive mechanism has the potential to be the basis of a gene
therapy-free therapeutical approach for light-based β-cell expansion."
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Eva
full_name: Gschaider-Reichhart, Eva
id: 3FEE232A-F248-11E8-B48F-1D18A9856A87
last_name: Gschaider-Reichhart
orcid: 0000-0002-7218-7738
citation:
ama: Gschaider-Reichhart E. Optical and optogenetic control of proliferation and
survival . 2018. doi:10.15479/AT:ISTA:th_913
apa: Gschaider-Reichhart, E. (2018). Optical and optogenetic control of proliferation
and survival . Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:th_913
chicago: Gschaider-Reichhart, Eva. “Optical and Optogenetic Control of Proliferation
and Survival .” Institute of Science and Technology Austria, 2018. https://doi.org/10.15479/AT:ISTA:th_913.
ieee: E. Gschaider-Reichhart, “Optical and optogenetic control of proliferation
and survival ,” Institute of Science and Technology Austria, 2018.
ista: Gschaider-Reichhart E. 2018. Optical and optogenetic control of proliferation
and survival . Institute of Science and Technology Austria.
mla: Gschaider-Reichhart, Eva. Optical and Optogenetic Control of Proliferation
and Survival . Institute of Science and Technology Austria, 2018, doi:10.15479/AT:ISTA:th_913.
short: E. Gschaider-Reichhart, Optical and Optogenetic Control of Proliferation
and Survival , Institute of Science and Technology Austria, 2018.
date_created: 2018-12-11T11:46:22Z
date_published: 2018-01-08T00:00:00Z
date_updated: 2023-09-22T09:20:10Z
day: '08'
ddc:
- '571'
- '570'
degree_awarded: PhD
department:
- _id: HaJa
doi: 10.15479/AT:ISTA:th_913
file:
- access_level: closed
checksum: 697fa72ca36fb1b8ceabc133d58a73e5
content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
creator: dernst
date_created: 2019-04-05T09:28:03Z
date_updated: 2020-07-14T12:46:24Z
file_id: '6222'
file_name: 2018_THESIS_Gschaider-Reichhart_source.docx
file_size: 7012495
relation: source_file
- access_level: open_access
checksum: 58d7d1e9e58aeb7f061ab686b1d8a48c
content_type: application/pdf
creator: dernst
date_created: 2019-04-05T09:28:03Z
date_updated: 2020-07-14T12:46:24Z
file_id: '6223'
file_name: 2018_THESIS_Gschaider-Reichhart.pdf
file_size: 6355280
relation: main_file
file_date_updated: 2020-07-14T12:46:24Z
has_accepted_license: '1'
language:
- iso: eng
month: '01'
oa: 1
oa_version: Published Version
page: '107'
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
publist_id: '7405'
pubrep_id: '913'
related_material:
record:
- id: '1441'
relation: part_of_dissertation
status: public
- id: '1678'
relation: part_of_dissertation
status: public
- id: '2084'
relation: part_of_dissertation
status: public
- id: '1028'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Harald L
full_name: Janovjak, Harald L
id: 33BA6C30-F248-11E8-B48F-1D18A9856A87
last_name: Janovjak
orcid: 0000-0002-8023-9315
title: 'Optical and optogenetic control of proliferation and survival '
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: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2018'
...
---
_id: '52'
abstract:
- lang: eng
text: In this thesis we will discuss systems of point interacting fermions, their
stability and other spectral properties. Whereas for bosons a point interacting
system is always unstable this ques- tion is more subtle for a gas of two species
of fermions. In particular the answer depends on the mass ratio between these
two species. Most of this work will be focused on the N + M model which consists
of two species of fermions with N, M particles respectively which interact via
point interactions. We will introduce this model using a formal limit and discuss
the N + 1 system in more detail. In particular, we will show that for mass ratios
above a critical one, which does not depend on the particle number, the N + 1
system is stable. In the context of this model we will prove rigorous versions
of Tan relations which relate various quantities of the point-interacting model.
By restricting the N + 1 system to a box we define a finite density model with
point in- teractions. In the context of this system we will discuss the energy
change when introducing a point-interacting impurity into a system of non-interacting
fermions. We will see that this change in energy is bounded independently of the
particle number and in particular the bound only depends on the density and the
scattering length. As another special case of the N + M model we will show stability
of the 2 + 2 model for mass ratios in an interval around one. Further we will
investigate a different model of point interactions which was discussed before
in the literature and which is, contrary to the N + M model, not given by a limiting
procedure but is based on a Dirichlet form. We will show that this system behaves
trivially in the thermodynamic limit, i.e. the free energy per particle is the
same as the one of the non-interacting system.
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Thomas
full_name: Moser, Thomas
id: 2B5FC9A4-F248-11E8-B48F-1D18A9856A87
last_name: Moser
citation:
ama: Moser T. Point interactions in systems of fermions. 2018. doi:10.15479/AT:ISTA:th_1043
apa: Moser, T. (2018). Point interactions in systems of fermions. Institute
of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:th_1043
chicago: Moser, Thomas. “Point Interactions in Systems of Fermions.” Institute of
Science and Technology Austria, 2018. https://doi.org/10.15479/AT:ISTA:th_1043.
ieee: T. Moser, “Point interactions in systems of fermions,” Institute of Science
and Technology Austria, 2018.
ista: Moser T. 2018. Point interactions in systems of fermions. Institute of Science
and Technology Austria.
mla: Moser, Thomas. Point Interactions in Systems of Fermions. Institute
of Science and Technology Austria, 2018, doi:10.15479/AT:ISTA:th_1043.
short: T. Moser, Point Interactions in Systems of Fermions, Institute of Science
and Technology Austria, 2018.
date_created: 2018-12-11T11:44:22Z
date_published: 2018-09-04T00:00:00Z
date_updated: 2023-09-27T12:34:14Z
day: '04'
ddc:
- '515'
- '530'
- '519'
degree_awarded: PhD
department:
- _id: RoSe
doi: 10.15479/AT:ISTA:th_1043
file:
- access_level: open_access
checksum: fbd8c747d148b468a21213b7cf175225
content_type: application/pdf
creator: dernst
date_created: 2019-04-09T07:45:38Z
date_updated: 2020-07-14T12:46:37Z
file_id: '6256'
file_name: 2018_Thesis_Moser.pdf
file_size: 851164
relation: main_file
- access_level: closed
checksum: c28e16ecfc1126d3ce324ec96493c01e
content_type: application/zip
creator: dernst
date_created: 2019-04-09T07:45:38Z
date_updated: 2020-07-14T12:46:37Z
file_id: '6257'
file_name: 2018_Thesis_Moser_Source.zip
file_size: 1531516
relation: source_file
file_date_updated: 2020-07-14T12:46:37Z
has_accepted_license: '1'
language:
- iso: eng
month: '09'
oa: 1
oa_version: Published Version
page: '115'
project:
- _id: 25C878CE-B435-11E9-9278-68D0E5697425
call_identifier: FWF
grant_number: P27533_N27
name: Structure of the Excitation Spectrum for Many-Body Quantum Systems
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
publist_id: '8002'
pubrep_id: '1043'
related_material:
record:
- id: '5856'
relation: part_of_dissertation
status: public
- id: '154'
relation: part_of_dissertation
status: public
- id: '1198'
relation: part_of_dissertation
status: public
- id: '741'
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: Point interactions in systems of fermions
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2018'
...
---
_id: '69'
abstract:
- lang: eng
text: 'A qubit, a unit of quantum information, is essentially any quantum mechanical
two-level system which can be coherently controlled. Still, to be used for computation,
it has to fulfill criteria. Qubits, regardless of the system in which they are
realized, suffer from decoherence. This leads to loss of the information stored
in the qubit. The upper bound of the time scale on which decoherence happens is
set by the spin relaxation time. In this thesis I studied a two-level system consisting
of a Zeeman-split hole spin confined in a quantum dot formed in a Ge hut wire.
Such Ge hut wires have emerged as a promising material system for the realization
of spin qubits, due to the combination of two significant properties: long spin
coherence time as expected for group IV semiconductors due to the low hyperfine
interaction and a strong valence band spin-orbit coupling. Here, I present how
to fabricate quantum dot devices suitable for electrical transport measurements.
Coupled quantum dot devices allowed the realization of a charge sensor, which
is electrostatically and tunnel coupled to a quantum dot. By integrating the charge
sensor into a radio-frequency reflectometry setup, I performed for the first time
single-shot readout measurements of hole spins and extracted the hole spin relaxation
times in Ge hut wires.'
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Lada
full_name: Vukušić, Lada
id: 31E9F056-F248-11E8-B48F-1D18A9856A87
last_name: Vukušić
orcid: 0000-0003-2424-8636
citation:
ama: Vukušić L. Charge sensing and spin relaxation times of holes in Ge hut wires.
2018. doi:10.15479/AT:ISTA:TH_1047
apa: Vukušić, L. (2018). Charge sensing and spin relaxation times of holes in
Ge hut wires. Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:TH_1047
chicago: Vukušić, Lada. “Charge Sensing and Spin Relaxation Times of Holes in Ge
Hut Wires.” Institute of Science and Technology Austria, 2018. https://doi.org/10.15479/AT:ISTA:TH_1047.
ieee: L. Vukušić, “Charge sensing and spin relaxation times of holes in Ge hut wires,”
Institute of Science and Technology Austria, 2018.
ista: Vukušić L. 2018. Charge sensing and spin relaxation times of holes in Ge hut
wires. Institute of Science and Technology Austria.
mla: Vukušić, Lada. Charge Sensing and Spin Relaxation Times of Holes in Ge Hut
Wires. Institute of Science and Technology Austria, 2018, doi:10.15479/AT:ISTA:TH_1047.
short: L. Vukušić, Charge Sensing and Spin Relaxation Times of Holes in Ge Hut Wires,
Institute of Science and Technology Austria, 2018.
date_created: 2018-12-11T11:44:28Z
date_published: 2018-09-01T00:00:00Z
date_updated: 2023-09-26T15:50:22Z
day: '01'
ddc:
- '530'
- '600'
degree_awarded: PhD
department:
- _id: GeKa
- _id: GradSch
doi: 10.15479/AT:ISTA:TH_1047
file:
- access_level: open_access
checksum: c570b656e30749cd65b1c7e13a9ce0a8
content_type: application/pdf
creator: dernst
date_created: 2019-04-09T07:00:40Z
date_updated: 2020-07-14T12:47:44Z
file_id: '6247'
file_name: 2018_Thesis_Vukusic.pdf
file_size: 28452385
relation: main_file
- access_level: closed
checksum: 7856771d9cd401fe0b311191076db6e1
content_type: application/zip
creator: dernst
date_created: 2019-04-09T07:00:40Z
date_updated: 2020-07-14T12:47:44Z
file_id: '6248'
file_name: 2018_Thesis_Vukusic_source.zip
file_size: 53058704
relation: source_file
file_date_updated: 2020-07-14T12:47:44Z
has_accepted_license: '1'
language:
- iso: eng
month: '09'
oa: 1
oa_version: Published Version
page: '103'
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
publist_id: '7985'
pubrep_id: '1047'
related_material:
record:
- id: '23'
relation: part_of_dissertation
status: public
- id: '840'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Georgios
full_name: Katsaros, Georgios
id: 38DB5788-F248-11E8-B48F-1D18A9856A87
last_name: Katsaros
orcid: 0000-0001-8342-202X
title: Charge sensing and spin relaxation times of holes in Ge hut wires
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: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2018'
...