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result(s) for
"Baumann, Julia"
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Self-control and performance while working from home
by
Danilov, Anastasia
,
Baumann, Julia
,
Stavrova, Olga
in
Adjustment
,
Biology and Life Sciences
,
Coronaviruses
2023
This study explores the role of trait self-control in individuals’ changes in performance and well-being when working from home (WFH). In a three-wave longitudinal study with UK workers in the midst of the COVID-19 pandemic, we find that low self-control workers experienced a significant positive adjustment to WFH over time: The number of reported work distractions decreased, and self-assessed performance increased over the period of four months. In contrast, high self-control individuals did not show a similar upward trajectory. Despite the positive adjustment of low self-control individuals over time, on average, self-control was still positively associated with performance and negatively associated with work distractions. However, trait self-control was not consistently associated with changes in well-being. These findings provide a more nuanced view on trait self-control, suggesting that low self-control individuals can improve initial performance over time when working from home.
Journal Article
A closer look reveals hidden diversity in the intertidal Caribbean Fortuyniidae (Acari, Oribatida)
by
Schäffer, Sylvia
,
Bardel-Kahr, Iris
,
Pfingstl, Tobias
in
Algae
,
Analysis
,
Biology and Life Sciences
2022
A molecular genetic and morphometric investigation revealed the supposedly widespread Caribbean and Western Atlantic intertidal oribatid mite species Fortuynia atlantica to comprise at least two different species. Although there are no distinct morphological differences separating these taxa, COI and 18S sequence divergence data, as well as different species delimitation analyses, clearly identify the two species. Fortuynia atlantica is distributed in the northern Caribbean and the Western Atlantic and the new Fortuynia antillea sp. nov. is presently endemic to Barbados. Vicariance is supposed to be responsible for their genetic diversification and stabilizing selection caused by the extreme intertidal environment is suggested to be the reason for the found morphological stasis. The genetic structure of Fortuynia atlantica indicates that Bermudian populations are derived from the northern Caribbean and thus support the theory of dispersal by drifting on the Gulf Stream. Haplotype network data suggest that Bermudian and Bahamian populations were largely shaped by colonization, expansion and extinction events caused by dramatic sea level changes during the Pleistocene. A preliminary phylogenetic analysis based on 18S gene sequences indicates that the globally distributed genus Fortuynia may be a monophyletic group, whereas Caribbean and Western Atlantic members are distinctly separated from the Indo-Pacific and Western Pacific species.
Journal Article
Morphological diversification among island populations of intertidal mites (Acari, Oribatida, Fortuyniidae) from the Galápagos archipelago
2017
The intertidal oribatid mite species
Alismobates galapagoensis
and
Litoribates caelestis
occur on the archipelago of Galápagos. To test for morphological variation between populations of different islands, a comprehensive morphometric study was performed. Four
A. galapagoensis
populations from the islands Bartolomé, Isabela, Santa Cruz and San Cristobal, as well as two
L. caelestis
populations from Bartolomé and Santa Cruz were investigated. The
L. caelestis
populations did not show any significant differences whereas the
A. galapagoensis
populations exhibited clear divergences indicating speciation. Differences in overall size of
A. galapagoensis
apparently followed a gradient from East to West, with specimens from San Cristóbal being the largest and individuals from Bartolomé and Isabela being the smallest. Apart from size, significant shape differences were found in the epimeral region and females showed stronger variation among islands than males. The degree of morphological divergence seems to correlate with geographic distance, i.e. populations from islands located closer to each other showed fewer differences than populations from distant islands. Based on this correlation we suggest that transport between islands has happened mainly by drifting on ocean currents.
Journal Article
Bulk RNA Barcode Sequencing Reveals Role of RNA Splicing in Aging Dermal Stem Cell Modulation by a Botanical Extract
2024
Skin aging is a complex, multifaceted process influenced by both intrinsic and extrinsic factors. Understanding the molecular mechanisms underlying skin aging is crucial for developing effective anti-aging strategies. Dermal stem cells play a pivotal role in maintaining skin homeostasis, but their functionality is compromised with aging. This study investigated the impact of aging on dermal stem cells and explored the potential of natural extracts in modulating their biological characteristics. Using bulk RNA barcoding and sequencing (BRB-seq), we identified differentially expressed genes (DEGs) between young and aged dermal stem cells, revealing alterations in cellular processes, including cell proliferation, ECM synthesis, and RNA splicing. We also demonstrated that a natural extract, comprising callus cells and Alpine rose leaf extracts, influenced RNA splicing in aged dermal stem cells, leading to improved dermal structure and integrity in vitro. Our findings suggest that natural extracts may exert their effects through senolytic activity and the modulation of RNA splicing, a process crucial to gene expression and cellular function. This study underscores the potential of integrating high-throughput transcriptomics in understanding skin aging, presenting new avenues for the development of innovative, sustainable, and effective anti-aging strategies.
Journal Article
Patterns of intraspecific morphological variability in soil mites reflect their dispersal ability
2021
The ability to disperse is one of the most important factors influencing the biogeography of species and speciation processes. Highly mobile species have been shown to lack geographic population structures, whereas less mobile species show genetically strongly subdivided populations which are expected to also display at least subtle phenotypic differences. Geometric morphometric methods (GMM) were now used to analyze morphological differences between European populations of a presumed non-phoretic, little mobile mite species in comparison to a highly mobile, phoretic species. The non-phoretic species Scutacarus carinthiacus showed a phenotypic population structure, whereas the phoretic species S. acarorum displayed homogeneity. These different patterns most probably can be explained by different levels of gene flow due to different dispersal abilities of the two species. GMM proved to be a sensitive tool that is especially recommendable for the analysis of (old) museum material and/or specimens in microscopic slides, which are not suitable for molecular genetic analysis.
Journal Article
Pericyte, but not astrocyte, hypoxia inducible factor-1 (HIF-1) drives hypoxia-induced vascular permeability in vivo
by
Köster-Hegmann, Christina
,
Francia, Simona
,
Tsao, Chih-Chieh
in
Animal genetic engineering
,
Animals
,
Astrocytes - metabolism
2022
Background
Ways to prevent disease-induced vascular modifications that accelerate brain damage remain largely elusive. Improved understanding of perivascular cell signalling could provide unparalleled insight as these cells impact vascular stability and functionality of the neurovascular unit as a whole. Identifying key drivers of astrocyte and pericyte responses that modify cell–cell interactions and crosstalk during injury is key. At the cellular level, injury-induced outcomes are closely entwined with activation of the hypoxia-inducible factor-1 (HIF-1) pathway. Studies clearly suggest that endothelial HIF-1 signalling increases blood–brain barrier permeability but the influence of perivascular HIF-1 induction on outcome is unknown. Using novel mouse lines with astrocyte and pericyte targeted HIF-1 loss of function, we herein show that vascular stability in vivo is differentially impacted by perivascular hypoxia-induced HIF-1 stabilization.
Methods
To facilitate HIF-1 deletion in adult mice without developmental complications, novel Cre-inducible astrocyte-targeted (GFAP-CreER
T2
; HIF-1α
fl/fl
and GLAST-CreER
T2
; HIF-1α
fl/fl
) and pericyte-targeted (SMMHC-CreER
T2
; HIF-1α
fl/fl
) transgenic animals were generated. Mice in their home cages were exposed to either normoxia (21% O
2
) or hypoxia (8% O
2
) for 96 h in an oxygen-controlled humidified glove box. All lines were similarly responsive to hypoxic challenge and post-Cre activation showed significantly reduced HIF-1 target gene levels in the individual cells as predicted.
Results
Unexpectedly, hypoxia-induced vascular remodelling was unaffected by HIF-1 loss of function in the two astrocyte lines but effectively blocked in the pericyte line. In correlation, hypoxia-induced barrier permeability and water accumulation were abrogated only in pericyte targeted HIF-1 loss of function mice. In contrast to expectation, brain and serum levels of hypoxia-induced VEGF, TGF-β and MMPs (genes known to mediate vascular remodelling) were unaffected by HIF-1 deletion in all lines. However, in agreement with the permeability data, immunofluorescence and electron microscopy showed clear prevention of hypoxia-induced tight junction disruption in the pericyte loss of function line.
Conclusion
This study shows that pericyte but not astrocyte HIF-1 stabilization modulates endothelial tight junction functionality and thereby plays a pivotal role in hypoxia-induced vascular dysfunction. Whether the cells respond similarly or differentially to other injury stimuli will be of significant relevance.
Journal Article
Astrocyte-specific hypoxia-inducible factor 1 (HIF-1) does not disrupt the endothelial barrier during hypoxia in vitro
by
Huang, Sheng-Fu
,
Baumann, Julia
,
Ogunshola, Omolara O.
in
Angiogenesis
,
Astrocytes
,
Barrier stability
2021
Background
Astrocytes (AC) are essential for brain homeostasis. Much data suggests that AC support and protect the vascular endothelium, but increasing evidence indicates that during injury conditions they may lose their supportive role resulting in endothelial cell activation and BBB disturbance. Understanding the triggers that flip this switch would provide invaluable information for designing new targets to modulate the brain vascular compartment. Hypoxia-inducible factor-1 (HIF-1) has long been assumed to be a culprit for barrier dysfunction as a number of its target genes are potent angiogenic factors. Indeed AC themselves, reservoirs of an array of different growth factors and molecules, are frequently assumed to be the source of such molecules although direct supporting evidence is yet to be published. Being well known reservoirs of HIF-1 dependent angiogenic molecules, we asked if AC HIF-1 dependent paracrine signaling drives brain EC disturbance during hypoxia.
Methods
First we collected conditioned media from control and siRNA-mediated HIF-1 knockdown primary rat AC that had been exposed to normoxic or hypoxic conditions. The conditioned media was then used to culture normoxic and hypoxic (1% O
2
) rat brain microvascular EC (RBE4) for 6 and 24 h. Various activation parameters including migration, proliferation and cell cycling were assessed and compared to untreated controls. In addition, tight junction localization and barrier stability per se (via permeability assay) was evaluated.
Results
AC conditioned media maintained both normoxic and hypoxic EC in a quiescent state by suppressing EC metabolic activity and proliferation. By FACs we observed reduced cell cycling with an increased number of cells in G0 phase and reduced cell numbers in M phase compared to controls. EC migration was also blocked by AC conditioned media and in correlation hypoxic tight junction organization and barrier functionality was improved. Surprisingly however, AC HIF-1 deletion did not impact EC responses or barrier stability during hypoxia.
Conclusions
This study demonstrates that AC HIF-1 dependent paracrine signaling does not contribute to AC modulation of EC barrier function under normoxic or hypoxic conditions. Thus other cell types likely mediate EC permeability in stress scenarios. Our data does however highlight the continuous protective effect of AC on the barrier endothelium. Exploring these protective mechanisms in more detail will provide essential insight into ways to prevent barrier disturbance during injury and disease.
Journal Article
Species differentiation of scutacarid mites (Heterostigmatina) using multivariate morphometric methods
by
Jagersbacher-Baumann, Julia
in
anatomy & histology
,
Animal Ecology
,
Animal Genetics and Genomics
2014
The genera of the mite family Scutacaridae (Heterostigmatina) can be easily distinguished by certain qualitative traits, whereas the species of these genera are lacking conspicuous distinctive features and thus, species descriptions are often based on quantitative characters. However, the intraspecific variability of these traits can be pronounced and the applicability of multivariate morphometric methods for species differentiation has not been studied so far. In the present study, four members of the genus Scutacarus, referred to as the acarorum species-complex, were analysed using traditional and geometric morphometric methods. The results showed that multivariate morphometric methods are perfectly suitable for differentiating even between morphologically similar scutacarid species, with traditional morphometrics performing better than geometric morphometrics. Despite their morphological similarity, morphometric analyses support the species status of the four members of the species-complex.
Journal Article
Hidden in the mangrove forest: the cryptic intertidal mite Carinozetes mangrovi sp. nov. (Acari, Oribatida, Selenoribatidae)
by
Pfingstl, Tobias
,
Jagersbacher-Baumann, Julia
,
Lienhard, Andrea
in
Acari
,
Acari - classification
,
Acari - genetics
2014
The small archipelago of Bermuda is a geologically young landmass in the Western Atlantic Ocean and recently turned out to be inhabited by a number of intertidal oribatid mites. One newly described species,
Carinozetes bermudensis
, showed an unusual vast range of habitats like sandy beaches, rocky substrate and mangroves. In the present study, 13 Bermudian populations of
C. bermudensis
were analysed to verify species integrity of specimens from different microhabitats. A morphometric analysis of 17 continuous variables as well as a molecular genetic investigation of the mitochondrial cytochrome oxidase subunit I revealed the existence of a new species
Carinozetes mangrovi
sp. nov., inhabiting exclusively intertidal algae growing on mangrove roots. Although both species are morphologically nearly identical, the configuration of the genus-specific ventral carinae represents a clear diagnostic character. The high genetic divergence of approximately 12 % of the cytochrome oxidase subunit I gene sequence between
C. bermudensis
and
C. mangrovi
sp. nov. suggests that these two species diverged before the emergence of the Bermuda islands. Accordingly, both of them are older than the geologically young archipelago of Bermuda.
Journal Article
Pericyte hypoxia-inducible factor-1 (HIF-1) drives blood-brain barrier disruption and impacts acute ischemic stroke outcome
by
Schroeter, Aileen
,
Kachappilly Nicole
,
Tsao Chih-Chieh
in
Blood vessels
,
Blood-brain barrier
,
Brain injury
2021
Pericytes play essential roles in blood-brain barrier integrity and their dysfunction is implicated in neurological disorders such as stroke although the underlying mechanisms remain unknown. Hypoxia-inducible factor-1 (HIF-1), a master regulator of injury responses, has divergent roles in different cells especially during stress scenarios. On one hand HIF-1 is neuroprotective but on the other it induces vascular permeability. Since pericytes are critical for barrier stability, we asked if pericyte HIF-1 signaling impacts barrier integrity and injury severity in a mouse model of ischemic stroke. We show that pericyte HIF-1 loss of function (LoF) diminishes ischemic damage and barrier permeability at 3 days reperfusion. HIF-1 deficiency preserved barrier integrity by reducing pericyte death thereby maintaining vessel coverage and junctional protein organization, and suppressing vascular remodeling. Importantly, considerable improvements in sensorimotor function were observed in HIF-1 LoF mice indicating that better vascular functionality post stroke improves outcome. Thus, boosting vascular integrity by inhibiting pericytic HIF-1 activation and/or increasing pericyte survival may be a lucrative option to accelerate recovery after severe brain injury.
Journal Article