Blockade but not overexpression of the junctional adhesion molecule C influences virus-induced type 1 diabetes in mice

Type 1 diabetes (T1D) results from the autoimmune destruction of insulin-producing beta-cells in the pancreas. Recruitment of inflammatory cells is prerequisite to beta-cell-injury. The junctional adhesion molecule (JAM) family proteins JAM-B and JAM–C are involved in polarized leukocyte transendothelial migration and are expressed by vascular endothelial cells of peripheral tissue and high endothelial venules in lympoid organs. Blocking of JAM-C efficiently attenuated cerulean-induced pancreatitis, rheumatoid arthritis or inflammation induced by ischemia and reperfusion in mice. In order to investigate the influence of JAM-C on trafficking and transmigration of antigen-specific, autoaggressive T-cells, we used transgenic mice that express a protein of the lymphocytic choriomeningitis virus (LCMV) as a target autoantigen in the β-cells of the islets of Langerhans under the rat insulin promoter (RIP). Such RIP-LCMV mice turn diabetic after infection with LCMV. We found that upon LCMV-infection JAM-C protein was upregulated around the islets in RIP-LCMV mice. JAM-C expression correlated with islet infiltration and functional beta-cell impairment. Blockade with a neutralizing anti-JAM-C antibody reduced the T1D incidence. However, JAM-C overexpression on endothelial cells did not accelerate diabetes in the RIP-LCMV model. In summary, our data suggest that JAM-C might be involved in the final steps of trafficking and transmigration of antigen-specific autoaggressive T-cells to the islets of Langerhans

Older adults’ neural tracking of interrupted speech is a function of task difficulty

Age-related hearing loss is a highly prevalent condition, which manifests at both the auditory periphery and the brain. It leads to degraded auditory input, which needs to be repaired in order to achieve understanding of spoken language. It is still unclear how older adults with this condition draw on their neural resources to optimally process speech. By presenting interrupted speech to 26 healthy older adults with normal-for-age audiograms, this study investigated neural tracking of degraded auditory input. The electroencephalograms of the participants were recorded while they first listened to and then verbally repeated sentences interrupted by silence in varying interruption rates. Speech tracking was measured by inter-trial phase coherence in response to the stimuli. In interruption rates that corresponded to the theta frequency band, speech tracking was highly specific to the interruption rate and positively related to the understanding of interrupted speech. These results suggest that older adults’ brain activity optimizes through the tracking of stimulus characteristics, and that this tracking aids in processing an incomplete auditory stimulus. Further investigation of speech tracking as a candidate training mechanism to alleviate age-related hearing loss is thus encouraged

Dielectric properties of perovskites with polar disorder (K1-xLix TaO3 and Pb[Mg1/3Nb2/3]O3) and of SrTiO3 films

Dielectric properties of perovskites are studied both to gain insight into fundamental aspects of the freezing of polar disorder, and to investigate their technological potential. The dynamics of freezing of polar disorder is investigated in single crystals of Li-doped potassium tantalate (K1-xLixTaO3) and lead magnesium niobate (pb[Mg1/3Nb2/3]O3). For the mixed crystal K1-xLixTaO3, the dielectric permittivity ε (ω) is measured at various temperatures and for frequencies ω/2π ranging from 2 × 10-4 to 109 Hz. These results are complemented by measurements of field-induced pyroelectric currents and polarization vs field loops. Further information is gained from microscopic model calculations of the Li-Li interaction energy. The present study reveals that this material can neither be described by a spin-glass model nor as a ferroelectric. In particular, the polarization of previously reported nanometer-sized clusters cannot be switched by an applied electric field. The analysis of the numerical results of the Li-Li interaction energy reveals the importance of elastic interactions. Nearest-neighbor effects are observed in the shape of the ε (ω) curves. Finally, the freezing of disorder is interpreted as a consequence of hierarchical constraints. For the "prototype" relaxor Pb(Mg1/3Nb2/3)O3, a comparison between new dielectric results and published data provides evidence of two relaxation branches. Phenomenologically, they bear strong similarities to those of glass-forming polymers and are thus labelled α- and β-type relaxations. The α branch is responsible for the characteristic peak in the temperature dependence of the permittivity. The parameters describing this relaxation show no anomalies or extrema in the investigated temperature range, and the peak is seen to be of purely dynamic origin, rather than being related to a structural phase transition. This confirms earlier claims that Pb(Mg1/3Nb2/3)O3 is nontransforming in the absence of an applied electric field. Motivated by a technological interest in highly polarizable dielectric layers, epitaxial SrTiO3 films with thicknesses between 50 and 330 nm are studied using Mg/SrTiO3/-SrTiO3:Nb heterostructures. Their low-temperature dielectric properties differ from those of single-crystal SrTiO3 samples, but can be understood in the framework of a simple model built for this purpose. This approach takes into consideration the non-linear polarization vs field dependence of SrTiO3 and assumes strong charge trapping at the film/substrate interface. The present films are characterized by a high permittivity: ε ≈ 100 is reproducibly obtained at 4.2 K, corresponding to capacitances of the order of 10 nF/mm2. Large charge densities (80 mC/m2) can be induced by applied voltages as low as ± 5 V

Im Tandem durch die Krise: Arbeit im Jobsharing während der COVID-19-Pandemie

Die COVID-19-Krise verändert die Arbeitswelt. Der Lockdown zur Eindämmung der Pandemie ging in den Betrieben mit der weitgehenden Umstellung auf die Arbeit im "Homeoffice" einher: die Nutzung der betrieblichen Räume wurde stark eingeschränkt, Besprechungen wurden größtenteils auf Onlineformate umgestellt. In dieser Studie untersuchen wir, wie sich die COVID-19-Krise auf die Arbeitssituation der Jobsharer*innen in Deutschland ausgewirkt hat. Basierend auf einer Onlinebefragung von Jobsharer*innen zeigen wir, dass sich das Jobsharing-Modell als sehr robust erweist. Die Jobsharer*innen können während der Krise die Flexibilität, aber auch die Unterstützung und die strategischen Vorteile der Abstimmung und Entscheidung im Tandem nutzen, was ihnen die Bewältigung der neuen Belastungen erleichtert.The COVID-19 crisis is changing the world of work. The lockdown to contain the pandemic was accompanied in the companies by the extensive shift to work at home: the presence of employees on the companies' premises was severely restricted, meetings were largely converted to online formats. In this study we investigate how the COVID-19 crisis has affected the work situation of jobsharers in Germany. Based on an online survey of jobsharers, we show that the jobsharing model has proven to be very robust. During the crisis, the jobsharers could take advantage of the flexibility, but also the support and strategic advantages of joint decision-making with their jobsharing partner, which made it easier for them to cope with the new challenges

RUCS: Rapid identification of PCR primers for unique core sequences

Abstract Motivation Designing PCR primers to target a specific selection of whole genome sequenced strains can be a long, arduous and sometimes impractical task. Such tasks would benefit greatly from an automated tool to both identify unique targets, and to validate the vast number of potential primer pairs for the targets in silico. Results Here we present RUCS, a program that will find PCR primer pairs and probes for the unique core sequences of a positive genome dataset complement to a negative genome dataset. The resulting primer pairs and probes are in addition to simple selection also validated through a complex in silico PCR simulation. We compared our method, which identifies the unique core sequences, against an existing tool called ssGeneFinder, and found that our method was 6.5–20 times more sensitive. We used RUCS to design primer pairs that would target a set of genomes known to contain the mcr-1 colistin resistance gene. Three of the predicted pairs were chosen for experimental validation using PCR and gel electrophoresis. All three pairs successfully produced an amplicon with the target length for the samples containing mcr-1 and no amplification products were produced for the negative samples. The novel methods presented in this manuscript can reduce the time needed to identify target sequences, and provide a quick virtual PCR validation to eliminate time wasted on ambiguously binding primers. Availability and implementation Source code is freely available on https://bitbucket.org/genomicepidemiology/rucs. Web service is freely available on https://cge.cbs.dtu.dk/services/RUCS. Supplementary information Supplementary data are available at Bioinformatics online. </jats:sec

Interaction induced magnetic field asymmetry of nonlinear mesoscopic electrical transport

We demonstrate that the nonlinear I-V characteristics of a two probe conductor is not an even function of magnetic field. While the conductance of a two-probe conductor is even in magnetic field, we find that already the contributions to the current which are second order in voltage, are in general not even. This implies a departure from the Onsager microreversibility principle already in the weakly nonlinear regime. Interestingly, the effect that we find is due to the Coulomb interaction. A measurement of the magnetic field asymmetry can be used to determine the effective interaction strength. As a generic example, we discuss the I-V characteristics of a chaotic quantum dot. The ensemble averaged I-V of such a cavity is linear: nonlinearities are due to quantum interference. Consequently, phase-breaking reduces the asymmetry. We support this statement with a calculation which treats inelastic scattering with the help of a voltage probe.Comment: 45th Sanibel Symposium, submitted April 6, 200

Scattering Theory of Mesoscopic Detectors

We consider a two-level system coupled to a mesoscopic two-terminal conductor that acts as measuring device. As a convenient description of the conductor we introduce its scattering matrix. We show how its elements can be used to calculate the relaxation and decoherence rates of the two-level system. Special emphasis is laid on the charge screening in the conductor that becomes important in the many-channel limit. Finally we give some examples that illustrate charge screening in different limits.Comment: contribution to the ECOSS-21 proceedings in a special issue of SURFACE SCIENC

"Ich arbeite ganz anders und besser als früher": Praxis und Potentiale von Jobsharing in Unternehmen

Der Begriff Jobsharing bezeichnet Arbeitsmodelle, in denen sich zwei in Teilzeit arbeitende Personen im Tandem einen Arbeitsplatz teilen. Der Fokus der hier vorliegenden Studie liegt dabei auf Positionen mit Führungsverantwortung bzw. mit anspruchsvollen Expertenaufgaben. Untersucht werden die Fragen: (1) Wie gestalten Unternehmen die Rahmenbedingungen und Regeln des Jobsharing? (2) Wie nehmen die Jobsharer*innen die Arbeit im Tandem sowie die Auswirkungen auf Arbeitsorganisation, Karrierechancen und die Work-Life-Balance wahr? (3) Welche Typen von Jobsharingtandems gibt es und wie unterscheiden sie sich im Hinblick auf Funktionsweise und Arbeitsorganisation? Die Untersuchung beruht auf einer 2019 durchgeführten Befragung in zehn Unternehmen, in denen Jobsharing praktiziert wird, und kombiniert drei Arten der Datenerhebung und Analyse: Interviews mit Vertreter*innen der Personalabteilungen, eine quantitative Onlinebefragung der Jobsharer*innen und leitfadengestützte Interviews mit Jobsharer*innen. Die Studie zeigt, dass die befragten Jobsharer*innen ihre Arbeitssituation insgesamt sehr positiv bewerten. Am kritischsten werden die Karriereeffekte, also der Einfluss der Arbeit im Jobsharing auf ihre Chancen des beruflichen Fortkommens, sowie der Zeitdruck und Arbeitsstress wahrgenommen. Zugleich zeigt die Studie, dass es unterschiedliche Typen von Jobsharingtandems gibt, die sich im Hinblick auf Zustandekommen und auch Arbeitssituation unterscheiden: "symbiotische Karrieretandems", "fremdbestimmte Tandems", "Sparringspartner*innen im höheren Management" und "strategische Bündnisse im höheren Management".The term job sharing refers to work arrangements in which two people working part-time share a workplace in tandem. The focus of this study is on job sharing positions with leadership responsibility or demanding expert tasks. The following questions are examined: (1) How do companies shape the general conditions and rules of job sharing? (2) How do job sharers perceive the work in a tandem and its effects on work organization, career opportunities and work-life balance? (3) What types of job sharing tandems exist and how do they differ in terms of work organisation? The study was conducted in 2019 in ten companies which offer job sharing. It combines three types of data collection and analysis: interviews with HR representatives, a standardized online survey of job sharers and semi-structured in-depth interviews with job sharers. The study shows that job sharers assess their work situation very positively overall. Aspects which are seen more critically are the career effects, i.e. the influence of job sharing on their chances of career advancement, as well as time pressure and work stress. In addition, the study shows that there are four types of job-sharing tandems that differ in terms of how they come about and how the work situation is perceived: "symbiotic career tandems", "involuntary tandems", "sparring partners in senior management" and "strategic alliances in senior management"