65 research outputs found
All-electrical measurements of direct spin Hall effect in GaAs with Esaki diode electrodes
We report on measurements of direct spin Hall effect in a lightly n-doped
GaAs channel. As spin detecting contacts we employed highly efficient
ferromagnetic Fe/(Ga,Mn)As/GaAs Esaki diode structures. We investigate bias and
temperature dependence of the measured spin Hall signal and evaluate the value
of total spin Hall conductivity and its dependence on channel conductivity and
temperature. From the results we determine skew scattering and side jump
contribution to the total spin hall conductivity and compare it with the
results of experiments on higher conductive n-GaAs channels[Phys. Rev. Lett.
105,156602(2010)]. As a result we conclude that both skewness and side jump
contribution cannot be fully independent on the conductivity of the channel.Comment: 14 pages, 4 figure
Expression patterns within the Arabidopsis C/S1 bZIP transcription factor network: availability of heterodimerization partners controls gene expression during stress response and development
Members of the Arabidopsis group C/S1 basic leucine zipper (bZIP) transcription factor (TF) network are proposed to implement transcriptional reprogramming of plant growth in response to energy deprivation and environmental stresses. The four group C and five group S1 members form specific heterodimers and are, therefore, considered to cooperate functionally. For example, the interplay of C/S1 bZIP TFs in regulating seed maturation genes was analyzed by expression studies and target gene regulation in both protoplasts and transgenic plants. The abundance of the heterodimerization partners significantly affects target gene transcription. Therefore, a detailed analysis of the developmental and stress related expression patterns was performed by comparing promoter: GUS and transcription data. The idea that the C/S1 network plays a role in the allocation of nutrients is supported by the defined and partially overlapping expression patterns in sink leaves, seeds and anthers. Accordingly, metabolic signals strongly affect bZIP expression on the transcriptional and/or post-transcriptional level. Sucrose induced repression of translation (SIRT) was demonstrated for all group S1 bZIPs. In particular, transcription of group S1 genes strongly responds to various abiotic stresses, such as salt (AtbZIP1) or cold (AtbZIP44). In summary, heterodimerization and expression data provide a basic framework to further determine the functional impact of the C/S1 network in regulating the plant energy balance and nutrient allocation
The Flexible Ocean and Climate Infrastructure Version 1 (FOCI1): Mean State and Variability
A new Earth system model, the Flexible Ocean and Climate Infrastructure (FOCI), is introduced. A first version of FOCI consists of a global high-top atmosphere (ECHAM6.3) and an ocean model (NEMO3.6) as well as sea ice (LIM2) and land surface model components (JSBACH), which are coupled through the OASIS3-MCT software package. FOCI includes a number of optional modules which can be activated depending on the scientific question of interest. In the atmosphere, interactive stratospheric chemistry can be used (ECHAM6-HAMMOZ) to study, for example, the effects of the ozone hole on the climate system. In the ocean, a biogeochemistry model (MOPS) is available to study the global carbon cycle. A unique feature of FOCI is the ability to explicitly resolve mesoscale ocean eddies in specific regions. This is realized in the ocean through nesting; first examples for the Agulhas Current and the Gulf Stream systems are described here. FOCI therefore bridges the gap between coarse-resolution climate models and global high-resolution weather prediction and ocean-only models. It allows to study the evolution of the climate system on regional and seasonal to (multi-) decadal scales.
The development of FOCI resulted from a combination of the long-standing expertise in ocean and climate modeling in several research units and divisions at GEOMAR. FOCI will thus be used to complement and interpret long-term observations in the Atlantic, enhance the process understanding of the role of mesoscale oceanic eddies for large-scale oceanic and atmospheric circulation patterns, study feedback mechanisms with stratospheric processes, estimate future ocean acidification, improve the simulation of the Atlantic Meridional Overturning Circulation changes and their influence on climate, ocean chemistry and biology.
In this paper we present both the scientific vision for the development of FOCI as well as some technical details. This includes a first validation of the different model components using several configurations of FOCI. Results show that the model in its basic configuration runs stably under pre-industrial control as well as under historical forcing, and produces a mean climate and variability which compares well with observations, reanalysis products and other climate models. The nested configurations reduce some long-standing biases in climate models and are an important step forward to include the atmospheric response in multi-decadal eddy-rich configurations
Oxytocin Modulates the Cognitive Appraisal of the Own and Others Close Intimate Relationships
Close and intimate relationships are important promoters of health. Oxytocin and its association with social cognition have been investigated in a large number of studies, especially highlighting the neuropeptide's involvement in attachment behavior and intimate relationships. However, mixed findings on exogenous oxytocin application have led to the focus on moderators and mediators, suggesting that the effects are depended on specific factors - namely context and salience. The objective of the current study was to assess the effect of intranasal oxytocin on social appraisal of own and others' close intimate relationship characteristics. Different characteristics of relationships, including trust or closeness, between romantic couples (unknown and own) were assessed using the Couple Appraisal Task. In a randomized controlled double-blind cross-over within subject design, = 71 healthy men and women were investigated after receiving first intranasal oxytocin and 2 weeks later placebo, or vice versa. We found an oxytocin-induced increase in the positive appraisal of one's own overall relationship characteristics but not in the evaluation of the relationship of others. The present study - one of the first of its kind administrating oxytocin in a repeated measures cross-over design - adds further evidence to the mediating role of oxytocin in social cognition, specifically with regard to romantic relationship characteristics
Das vermessene Selbst - Praktiken und Diskurse digitaler Selbstvermessung
Sich selbst vermessen, quantitative Daten über die eigenen physischen, psychischen und geistigen Zustände gewinnen, sie dokumentieren, analysieren und veröffentlichen – das mag auf den ersten Blick befremdlich erscheinen. De facto lassen sich solche Praktiken jedoch in gesellschaftliche Entwicklungen einordnen, an denen ein jeder von uns teilhat: Praktiken digitaler Selbstvermessung werden durch die technische Entwicklung der vergangenen Jahre erst möglich, sie verweisen auf eine Verwissenschaftlichung der alltäglichen Lebensführung und spiegeln Disziplinierungs- und Optimierungsbestrebungen wider, die sich längst nicht mehr auf die Arbeitswelt beschränken. Warum erscheint es in diesem Kontext erstrebenswert, Erkenntnisse über sich selbst zu erlangen? Und wie genau sind die beschriebenen Praktiken beschaffen? Die vorliegende Grounded Theory basierte Studie gibt – nicht zuletzt aufgrund der Multidimensionalität ihres empirischen Zugangs und ihrer praxeologischen Theorieperspektive – vielfältige und detaillierte Einblicke in die Welt der Selbstvermessung
Monoclonal anti-β1-adrenergic receptor antibodies activate G protein signaling in the absence of β-arrestin recruitment
Thermostabilized G protein-coupled receptors used as antigens for in vivo immunization have resulted in the generation of functional agonistic anti-β1-adrenergic (β1AR) receptor monoclonal antibodies (mAbs). The focus of this study was to examine the pharmacology of these antibodies to evaluate their mechanistic activity at β1AR. Immunization with the β1AR stabilized receptor yielded five stable hybridoma clones, four of which expressed functional IgG, as determined in cell-based assays used to evaluate cAMP stimulation. The antibodies bind diverse epitopes associated with low nanomolar agonist activity at β1AR, and they appeared to show some degree of biased signaling as they were inactive in an assay measuring signaling through β-arrestin. In vitro characterization also verified different antibody-receptor interactions reflecting the different epitopes on the extracellular surface of β1AR to which the mAbs bind. The anti-β1AR mAbs only demonstrated agonist activity when in dimeric antibody format, but not as the monomeric Fab format, suggesting that agonist activation may be mediated through promoting receptor dimerization. Finally, we have also shown that at least one of these antibodies exhibits in vivo functional activity at a therapeutically-relevant dose producing an increase in heart rate consistent with β1AR agonism
The state of Fortran
A community of developers has formed to modernize the Fortran ecosystem. In this article, we describe the high-level features of Fortran that continue to make it a good choice for scientists and engineers in the 21st century. Ongoing efforts include the development of a Fortran standard library and package manager, the fostering of a friendly and welcoming online community, improved compiler support, and language feature development. The lessons learned are common across contemporary programming languages and help reduce the learning curve and increase adoption of Fortran
Alexithymia and interleukin variations in somatoform disorder
Objective: The aim of the present study was to investigate if somatoform disorders (SFD) are associated with changes in the normal serum levels of important interleukins, and further, to establish if these changes are related to the presence and severity of alexithymia in patients with SFD. Methods: Twenty-four unmedicated patients who met the International Classification of Diseases (ICD-10) diagnostic criteria for SFD completed the psychological questionnaire to assess alexithymia (Toronto Alexithymia Scale), symptom reporting (SCL-90-R) and diagnostic criteria for SFD (Screening for Somatoform Symptoms scale). Serum concentrations of soluble interleukin 2 receptor α (sIL-2 Rα), IL-4, IL-6, IL-10 and IL-12 were determined in patients with SFD and in 9 healthy subjects. Results: In patients with SFD, serum levels of IL-6 (p < 0.001), IL-10 (p = 0.047) and immunoglobulin E (p = 0.045) were significantly increased in comparison with healthy controls. Additionally, a negative correlation was observed between the level of alexithymia ('total' Toronto Alexithymia Scale score) and the serum levels of sIL-2 Rα (r = -0.538) in SFD. Conclusions: Taken together, these results suggest that SFD, with clinically significant alexithymia, are associated with a reduction in Th1-mediated immune function and an increase in the activation of the Th2 immune function, indicated by the augmented serum levels of IL-6 and IL-10 and elevated immunoglobulin E. Copyright © 2007 S. Karger AG
Antimicrobial use in pediatric oncology and hematology in Germany and Austria, 2020/2021: a cross-sectional, multi-center point-prevalence study with a multi-step qualitative adjudication process
Background
Due to the high risk of severe infection among pediatric hematology and oncology patients, antimicrobial use is particularly high. With our study, we quantitatively and qualitatively evaluated, based on institutional standards and national guidelines, antimicrobial usage by employing a point-prevalence survey with a multi-step, expert panel approach. We analyzed reasons for inappropriate antimicrobial usage.
Methods
This cross-sectional study was conducted at 30 pediatric hematology and oncology centers in 2020 and 2021. Centers affiliated to the German Society for Pediatric Oncology and Hematology were invited to join, and an existing institutional standard was a prerequisite to participate. We included hematologic/oncologic inpatients under 19 years old, who had a systemic antimicrobial treatment on the day of the point prevalence survey. In addition to a one-day, point-prevalence survey, external experts individually assessed the appropriateness of each therapy. This step was followed by an expert panel adjudication based upon the participating centers’ institutional standards, as well as upon national guidelines. We analyzed antimicrobial prevalence rate, along with the rate of appropriate, inappropriate, and indeterminate antimicrobial therapies with regard to institutional and national guidelines. We compared the results of academic and non-academic centers, and performed a multinomial logistic regression using center- and patient-related data to identify variables that predict inappropriate therapy.
Findings
At the time of the study, a total of 342 patients were hospitalized at 30 hospitals, of whom 320 were included for the calculation of the antimicrobial prevalence rate. The overall antimicrobial prevalence rate was 44.4% (142/320; range 11.1–78.6%) with a median antimicrobial prevalence rate per center of 44.5% (95% confidence interval [CI] 35.9–49.9). Antimicrobial prevalence rate was significantly higher (p < 0.001) at academic centers (median 50.0%; 95% CI 41.2–55.2) compared to non-academic centers (median 20.0%; 95% CI 11.0–32.4). After expert panel adjudication, 33.8% (48/142) of all therapies were labelled inappropriate based upon institutional standards, with a higher rate (47.9% [68/142]) when national guidelines were taken into consideration. The most frequent reasons for inappropriate therapy were incorrect dosage (26.2% [37/141]) and (de-)escalation/spectrum-related errors (20.6% [29/141]). Multinomial, logistic regression yielded the number of antimicrobial drugs (odds ratio, OR, 3.13, 95% CI 1.76–5.54, p < 0.001), the diagnosis febrile neutropenia (OR 0.18, 95% CI 0.06–0.51, p = 0.0015), and an existing pediatric antimicrobial stewardship program (OR 0.35, 95% CI 0.15–0.84, p = 0.019) as predictors of inappropriate therapy. Our analysis revealed no evidence of a difference between academic and non-academic centers regarding appropriate usage.
Interpretation
Our study revealed there to be high levels of antimicrobial usage at German and Austrian pediatric oncology and hematology centers with a significant higher number at academic centers. Incorrect dosing was shown to be the most frequent reason for inappropriate usage. Diagnosis of febrile neutropenia and antimicrobial stewardship programs were associated with a lower likelihood of inappropriate therapy. These findings suggest the importance of febrile neutropenia guidelines and guidelines compliance, as well as the need for regular antibiotic stewardship counselling at pediatric oncology and hematology centers.
Funding
European Society of Clinical Microbiology and Infectious Diseases, Deutsche Gesellschaft für Pädiatrische Infektiologie, Deutsche Gesellschaft für Krankenhaushygiene, Stiftung Kreissparkasse Saarbrücken
Transportuntersuchungen an strukturierten Ferromagnet/Halbleiter-Hybridstrukturen
In dieser Arbeit wurde die magnetische Wechselwirkung an der Grenzfläche zwischen einer weichmagnetischen Eisen (Fe) Schicht und einer hartmagnetischen Dysprosium (Dy) Schicht erforscht. Hierfür wurden wenige Nanometer dünne Fe/Dy Zweischichtsysteme durch Sputterdeposition auf Galliumarsenid (GaAs) Substraten gewachsen. Die magnetischen Eigenschaften der Fe/Dy Zweischichtsysteme wurden bei tiefen Temperaturen (5 – 120 K) per SQUID charakterisiert. Der Vergleich mit den magnetischen Eigenschaften von Fe bzw. Dy Einschichtsystemen zeigt, dass im Fe/Dy Zweischichtsystem die magnetischen Eigenschaften der Fe-Schicht durch die Exchange Spring Kopplung an der Fe/Dy Grenzfläche beeinflusst werden. Dadurch wird das Koerzitivfeld der Fe-Schicht um mehr als eine Größenordnung erhöht. In Übereinstimmung mit dem zugrunde liegenden Modell der Exchange Spring Kopplung konnte in den durchgeführten Experimenten zudem durch Variation der Fe-Schichtdicke die Erhöhung des Koerzitivfelds der Fe-Schicht gezielt eingestellt werden. Magnetotransportmessungen, die an mikrostrukturierten Fe/Dy Zweischichtsystemen mit gleicher Schichtfolge durchgeführt wurden, bestätigen die Ergebnisse der SQUID Messungen. Der magnetfeldabhängige Magnetisierungszustand der magnetischen Schichten konnte hier mit Hilfe des AMR-Effekts bestimmt werden.
Im zweiten Teil dieser Arbeit wurde der Spin-Galvanische Effekt (SGE) bei niedrigen Temperaturen (1.4 K) in einem GaAs basierenden zweidimensionalen Elektronengas (2DEG) untersucht. Hierfür wurde mit Hilfe einer Spin Esaki-Diode eine Spinkomponente entlang einer bestimmten kristallographischen Orientierung in das 2DEG injiziert. Durch den SGE tritt senkrecht zur Spinkomponente ein elektrischer Strom auf, wodurch die injizierte Spinkomponente rein elektrisch nachgewiesen werden kann. Experimentell weist die Magnetfeldabhängigkeit des detektierten elektrischen Stroms Eigenschaften auf, wie sie für den SGE zu erwarten sind. Der durch den SGE induzierte spinabhängige Anteil wird dabei jedoch von spinunabhängigen Komponenten überlagert
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