Showing papers by "Bielefeld University published in 2021"

Psychological Wellbeing and Academic Experience of University Students in Australia during COVID-19.

Abstract: COVID-19 has created significant challenges for higher education institutions and major disruptions in teaching and learning. To explore the psychological wellbeing of domestic and international university students during the COVID-19 pandemic, an online cross-sectional survey recruited 787 university students (18+ years) currently studying at an Australian university. In total, 86.8% reported that COVID-19 had significantly impacted their studies. Overall, 34.7% of students reported a sufficient level of wellbeing, while 33.8% showed low wellbeing and 31.5% very low wellbeing. Wellbeing was significantly higher in postgraduate students compared with undergraduate students. Future anxiety was significantly greater among undergraduate than postgraduate students. Multivariable regression models showed female gender, low subjective social status, negative overall learning experience or reporting COVID-19 having a huge impact on study, were associated with lower wellbeing in the first few months (May-July) of the pandemic. Supporting the health, wellbeing, and learning experiences of all students should be of high priority now and post-pandemic. Strategies specifically targeting female students, and those with low self-reported social status are urgently needed to avoid exacerbating existing disparities.

The LOFAR Two-meter Sky Survey: Deep Fields Data Release 1. I. Direction-dependent calibration and imaging

Abstract: The Low Frequency Array (LOFAR) is an ideal instrument to conduct deep extragalactic surveys. It has a large field of view and is sensitive to large-scale and compact emission. It is, however, very challenging to synthesize thermal noise limited maps at full resolution, mainly because of the complexity of the low-frequency sky and the direction dependent effects (phased array beams and ionosphere). In this first paper of a series, we present a new calibration and imaging pipeline that aims at producing high fidelity, high dynamic range images with LOFAR High Band Antenna data, while being computationally efficient and robust against the absorption of unmodeled radio emission. We apply this calibration and imaging strategy to synthesize deep images of the Bootes and Lockman Hole fields at ~150 MHz, totaling ~80 and ~100 h of integration, respectively, and reaching unprecedented noise levels at these low frequencies of ≲30 and ≲23 μ Jy beam−1 in the inner ~3 deg2 . This approach is also being used to reduce the LOTSS-wide data for the second data release.

CLIP and complementary methods

Abstract: RNA molecules start assembling into ribonucleoprotein (RNP) complexes during transcription. Dynamic RNP assembly, largely directed by cis-acting elements on the RNA, coordinates all processes in which the RNA is involved. To identify the sites bound by a specific RNA-binding protein on endogenous RNAs, cross-linking and immunoprecipitation (CLIP) and complementary, proximity-based methods have been developed. In this Primer, we discuss the main variants of these protein-centric methods and the strategies for their optimization and quality assessment, as well as RNA-centric methods that identify the protein partners of a specific RNA. We summarize the main challenges of computational CLIP data analysis, how to handle various sources of background and how to identify functionally relevant binding regions. We outline the various applications of CLIP and available databases for data sharing. We discuss the prospect of integrating data obtained by CLIP with complementary methods to gain a comprehensive view of RNP assembly and remodelling, unravel the spatial and temporal dynamics of RNPs in specific cell types and subcellular compartments and understand how defects in RNPs can lead to disease. Finally, we present open questions in the field and give directions for further development and applications. Ule and colleagues discuss cross-linking and immunoprecipitation (CLIP) methods for characterizing the RNA binding partners of RNA-binding proteins and explore the data analysis workflows, best practices and applications for these techniques. The Primer also considers methods for characterizing the protein binding partners of specific RNAs and discusses how data from these complementary methods can be integrated into CLIP workflows.

Common-red-signal analysis with 24-yr high-precision timing of the European Pulsar Timing Array: Inferences in the stochastic gravitational-wave background search

Abstract: We present results from the search for a stochastic gravitational-wave background (GWB) as predicted by the theory of General Relativity using six radio millisecond pulsars from the Data Release 2 (DR2) of the European Pulsar Timing Array (EPTA) covering a timespan up to 24 years. A GWB manifests itself as a long-term low-frequency stochastic signal common to all pulsars, a common red signal (CRS), with the characteristic Hellings-Downs (HD) spatial correlation. Our analysis is performed with two independent pipelines, \eprise and \tn+\ftwo, which produce consistent results. A search for a CRS with simultaneous estimation of its spatial correlations yields spectral properties compatible with theoretical GWB predictions, but does not result in the required measurement of the HD correlation, as required for GWB detection. Further Bayesian model comparison between different types of CRSs, including a GWB, finds the most favoured model to be the common uncorrelated red noise described by a power-law with $A = 5.13_{-2.73}^{+4.20} \times 10^{-15}$ and $\gamma = 3.78_{-0.59}^{+0.69}$ (95% credible regions). Fixing the spectral index to $\gamma=13/3$ as expected from the GWB by circular, inspiralling supermassive black-hole binaries results in an amplitude of $A =2.95_{-0.72}^{+0.89} \times 10^{-15}$. We implement three different models, BAYESEPHEM, LINIMOSS and EPHEMGP, to address possible Solar-system ephemeris (SSE) systematics and conclude that our results may only marginally depend on these effects. This work builds on the methods and models from the studies on the EPTA DR1. We show that under the same analysis framework the results remain consistent after the data set extension.

Water at charged interfaces

Abstract: The ubiquity of aqueous solutions in contact with charged surfaces and the realization that the molecular-level details of water–surface interactions often determine interfacial functions and properties relevant in many natural processes have led to intensive research. Even so, many open questions remain regarding the molecular picture of the interfacial organization and preferential alignment of water molecules, as well as the structure of water molecules and ion distributions at different charged interfaces. While water, solutes and charge are present in each of these systems, the substrate can range from living tissues to metals. This diversity in substrates has led to different communities considering each of these types of aqueous interface. In this Review, by considering water in contact with metals, oxides and biomembranes, we show the essential similarity of these disparate systems. While in each case the classical mean-field theories can explain many macroscopic and mesoscopic observations, it soon becomes apparent that such theories fail to explain phenomena for which molecular properties are relevant, such as interfacial chemical conversion. We highlight the current knowledge and limitations in our understanding and end with a view towards future opportunities in the field. What do a rock in a river, a red blood cell in our body and the electrodes inside a car battery have in common? Charged surfaces in contact with water. Although a unified approach to study such a variety of systems is not available yet, the current understanding — even with its limitations — paves the road to the development of new concepts and techniques.

Towards tellurium-free thermoelectric modules for power generation from low-grade heat

Abstract: Thermoelectric technology converts heat into electricity directly and is a promising source of clean electricity. Commercial thermoelectric modules have relied on Bi2Te3-based compounds because of their unparalleled thermoelectric properties at temperatures associated with low-grade heat (<550 K). However, the scarcity of elemental Te greatly limits the applicability of such modules. Here we report the performance of thermoelectric modules assembled from Bi2Te3-substitute compounds, including p-type MgAgSb and n-type Mg3(Sb,Bi)2, by using a simple, versatile, and thus scalable processing routine. For a temperature difference of ~250 K, whereas a single-stage module displayed a conversion efficiency of ~6.5%, a module using segmented n-type legs displayed a record efficiency of ~7.0% that is comparable to the state-of-the-art Bi2Te3-based thermoelectric modules. Our work demonstrates the feasibility and scalability of high-performance thermoelectric modules based on sustainable elements for recovering low-grade heat. Though earth abundant magnesium-based materials are attractive for thermoelectrics (TEs) due to their device-level performance, realizing efficient modules remains a challenge. Here, the authors report a scalable route to realizing Mg-based compounds for high performance TE modules.

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight

Abstract: From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions.

Health Literacy, Digital Health Literacy, and COVID-19 Pandemic Attitudes and Behaviors in U.S. College Students: Implications for Interventions.

Abstract: The COVID-19 pandemic has been accompanied by rapidly emerging evidence, changing guidance, and misinformation, which present new challenges for health literacy (HL) and digital health literacy (DHL) skills. This study explored whether COVID-19-related information access, attitudes, and behaviors were associated with health literacy and digital health literacy among college students in the United States. Self-reported measures of health literacy, along with items on pandemic-related attitudes, behaviors, information sources, and social networks, were collected online using a managed research panel. In July 2020, 256 responses were collected, which mirrored the racial/ethnic and gender diversity of U.S. colleges. Only 49% reported adequate HL, and 57% found DHL tasks easy overall. DHL did not vary by HL level. In multivariable models, both HL and DHL were independently associated with overall compliance with basic preventive practices. Higher DHL, but not HL, was significantly associated with greater willingness to get a COVID-19 vaccine and the belief that acquiring the disease would negatively impact their life. On average, respondents discussed health with 4-5 people, which did not vary by HL or DHL measures. The usage of online information sources varied by HL and DHL. The study findings can inform future student-focused interventions, including identifying the distinct roles of HL and DHL in pandemic information access, attitudes, and behaviors.

The LOFAR Two-meter Sky Survey: Deep Fields Data Release 1 - II. The ELAIS-N1 LOFAR deep field

Abstract: The LOFAR Two-metre Sky Survey (LoTSS) will cover the full northern sky and, additionally, aims to observe the LoTSS deep fields to a noise level of ~10 microJy/bm over several tens of square degrees in areas that have the most extensive ancillary data. This paper presents the ELAIS-N1 deep field, the deepest of the LoTSS deep fields to date. With an effective observing time of 163.7 hours, it reaches a root mean square (RMS) noise level below 20 microJy/bm in the central region (and below 30 microJy/bm over 10 square degrees). The resolution is 6 arcsecs and 84862 radio sources were detected in the full area (68 sq. deg.) with 74127 sources in the highest quality area at less than 3 degrees from the pointing centre. The observation reaches a sky density of more than 5000 sources per sq. deg. in the central ~5 sq. deg. region. We present the calibration procedure, which addresses the special configuration of some observations and the extended bandwidth covered (115 to 177 MHz; central frequency 146.2 MHz) compared to standard LoTSS. We also describe the methods used to calibrate the flux density scale using cross-matching with sources detected by other radio surveys in the literature. We find the flux density uncertainty related to the flux density scale to be ~6.5%. By studying the variations of the flux density measurements between different epochs, we show that relative flux density calibration is reliable out to about a 3 degree radius, but that additional flux density uncertainty is present for all sources at about the 3 per cent level; this is likely to be associated with residual calibration errors, and is shown to be more significant in datasets with poorer ionosphere conditions. We also provide intra-band spectral indices, which can be useful to detect sources with unusual spectral properties. The final uncertainty in the flux densities is estimated to be ~10% for ELAIS-N1.

Combustion in the future: The importance of chemistry

Abstract: Combustion involves chemical reactions that are often highly exothermic. Combustion systems utilize the energy of chemical compounds released during this reactive process for transportation, to generate electric power, or to provide heat for various applications. Chemistry and combustion are interlinked in several ways. The outcome of a combustion process in terms of its energy and material balance, regarding the delivery of useful work as well as the generation of harmful emissions, depends sensitively on the molecular nature of the respective fuel. The design of efficient, low-emission combustion processes in compliance with air quality and climate goals suggests a closer inspection of the molecular properties and reactions of conventional, bio-derived, and synthetic fuels. Information about flammability, reaction intensity, and potentially hazardous combustion by-products is important also for safety considerations. Moreover, some of the compounds that serve as fuels can assume important roles in chemical energy storage and conversion. Combustion processes can furthermore be used to synthesize materials with attractive properties. A systematic understanding of the combustion behavior thus demands chemical knowledge. Desirable information includes properties of the thermodynamic states before and after the combustion reactions and relevant details about the dynamic processes that occur during the reactive transformations from the fuel and oxidizer to the products under the given boundary conditions. Combustion systems can be described, tailored, and improved by taking chemical knowledge into account. Combining theory, experiment, model development, simulation, and a systematic analysis of uncertainties enables qualitative or even quantitative predictions for many combustion situations of practical relevance. This article can highlight only a few of the numerous investigations on chemical processes for combustion and combustion-related science and applications, with a main focus on gas-phase reaction systems. It attempts to provide a snapshot of recent progress and a guide to exciting opportunities that drive such research beyond fossil combustion.

Grating-Graphene Metamaterial as a Platform for Terahertz Nonlinear Photonics

Abstract: Nonlinear optics is an increasingly important field for scientific and technological applications, owing to its relevance and potential for optical and optoelectronic technologies. Currently, there is an active search for suitable nonlinear material systems with efficient conversion and a small material footprint. Ideally, the material system should allow for chip integration and room-temperature operation. Two-dimensional materials are highly interesting in this regard. Particularly promising is graphene, which has demonstrated an exceptionally large nonlinearity in the terahertz regime. Yet, the light-matter interaction length in two-dimensional materials is inherently minimal, thus limiting the overall nonlinear optical conversion efficiency. Here, we overcome this challenge using a metamaterial platform that combines graphene with a photonic grating structure providing field enhancement. We measure terahertz third-harmonic generation in this metamaterial and obtain an effective third-order nonlinear susceptibility with a magnitude as large as 3 × 10-8 m2/V2, or 21 esu, for a fundamental frequency of 0.7 THz. This nonlinearity is 50 times larger than what we obtain for graphene without grating. Such an enhancement corresponds to a third-harmonic signal with an intensity that is 3 orders of magnitude larger due to the grating. Moreover, we demonstrate a field conversion efficiency for the third harmonic of up to ∼1% using a moderate field strength of ∼30 kV/cm. Finally, we show that harmonics beyond the third are enhanced even more strongly, allowing us to observe signatures of up to the ninth harmonic. Grating-graphene metamaterials thus constitute an outstanding platform for commercially viable, CMOS-compatible, room-temperature, chip-integrated, THz nonlinear conversion applications.

Who Is Impacted? Personality Predicts Individual Differences in Psychological Consequences of the COVID-19 Pandemic in Germany

Abstract: The COVID-19 pandemic has led to changes in people’s private and public lives that are unprecedented in modern history. However, little is known about the differential psychological consequences of...

Baryogenesis from the weak scale to the grand unification scale

Abstract: The standard model of elementary particle physics, once augmented with Sakharov's conditions, offers several scenarios to explain today's matter-antimatter asymmetry. This survey evaluates the paths to baryogenesis. Of special interest is that time-reversal violation in neutrino physics, together with large mixings, seems poised to produce the observed asymmetry via leptogenesis. This review occurs at a time when several experiments are on the threshold of a precise measurement of time violation in lepton mixing.

Trends in suicide rates during the COVID-19 pandemic restrictions in a major German city.

Abstract: AIMS: It remains unclear whether the coronavirus disease 2019 (COVID-19) pandemic is having an impact on suicide rates (SR). Economic insecurity and mental disorders are risk factors for suicide, which may increase during the pandemic. METHODS: Data on suicide events in a major city in Germany, and the corresponding life years (LY) were provided by the local authorities. For the year 2020, periods without restrictions on freedom of movement and social contact were compared with periods of moderate and severe COVID-19 restrictions. To avoid distortions due to seasonal fluctuations and linear time trends, suicide risk during the COVID-19 pandemic was compared with data from 2010 to 2019 using an interrupted time series analysis. RESULTS: A total of 643 suicides were registered and 6 032 690 LY were spent between 2010 and 2020. Of these, 53 suicides and 450 429 LY accounted for the year 2020.In 2020, SR (suicides per 100 000 LY) were lower in periods with severe COVID-19 restrictions (SR = 7.2, χ2 = 4.033, p = 0.045) compared with periods without restrictions (SR = 16.8). A comparison with previous years showed that this difference was caused by unusually high SR before the imposition of restrictions, while SR during the pandemic were within the trend corridor of previous years (expected suicides = 32.3, observed suicides = 35; IRR = 1.084, p = 0.682). CONCLUSIONS: SR during COVID-19 pandemic are in line with the trend in previous years. Careful monitoring of SR in the further course of the COVID-19 crisis is urgently needed. The findings have regional reference and should not be over-generalised.

Advances in metabolic engineering of Corynebacterium glutamicum to produce high-value active ingredients for food, feed, human health, and well-being.

Abstract: The soil microbe Corynebacterium glutamicum is a leading workhorse in industrial biotechnology and has become famous for its power to synthetise amino acids and a range of bulk chemicals at high titre and yield. The product portfolio of the microbe is continuously expanding. Moreover, metabolically engineered strains of C. glutamicum produce more than 30 high value active ingredients, including signature molecules of raspberry, savoury, and orange flavours, sun blockers, anti-ageing sugars, and polymers for regenerative medicine. Herein, we highlight recent advances in engineering of the microbe into novel cell factories that overproduce these precious molecules from pioneering proofs-of-concept up to industrial productivity.

The (fe)male robot – How robot body shape impacts first impressions and trust towards robots

Abstract: Humanlikeness, including robot gender, impacts people’s impression of social robots (Eyssel and Hegel in J Appl Soc Psychol 42(9):2213–2230, 2012) and actual human robot interaction (HRI) (Kuchenbrandt et al. in Int J Soc Robot 6(3):417–427, 2014; Reich-Stiebert and Eyssel in Proceedings of the 2017 ACM/IEEE international conference on human–robot interaction, ACM, pp 166–176, 2017). Although robot gender has been manipulated in various ways in previous research (Alexander et al. in Proceedings of the annual meeting of the Cognitive Science Society, vol 36, 2014; Eyssel and Hegel, 2012), robot body shape as a gender cue has been neglected in this context. Therefore, the current research investigated the effects of manipulating a robot torso’s waist-to-hip ratio and shoulder width on social judgments of a robot. As hypothesized, a robot with a female body shape was perceived as more communal, it was preferred for stereotypically female tasks, and evoked more cognitive and affective trust than a robot with a male body shape. Unexpectedly, both robot types were perceived as equally agentic and they were deemed equally suitable for stereotypically male tasks. Above and beyond, participants’ motivation to respond in a socially desirable manner, their societal beliefs about agentic and communal traits considered appropriate for men and women, sexist attitudes, gender, and technology commitment affected their impression formation about robots. We point to the risks of designing gendered robots and recommend to manipulate robot gender deliberately with regard to the effects this might have on HRI.

Severe allergic reactions after COVID-19 vaccination with the Pfizer/BioNTech vaccine in Great Britain and USA: Position statement of the German Allergy Societies: Medical Association of German Allergologists (AeDA), German Society for Allergology and Clinical Immunology (DGAKI) and Society for Pediatric Allergology and Environmental Medicine (GPA).

Abstract: Two employees of the National Health Service (NHS) in England developed severe allergic reactions following administration of BNT162b2 vaccine against COVID-19 (coronavirus disease 2019). The British SmPC for the BNT162b2 vaccine already includes reference to a contraindication for use in individuals who have had an allergic reaction to the vaccine or any of its components. As a precautionary measure, the Medicines and Healthcare products Regulatory Agency (MHRA) has issued interim guidance to the NHS not to vaccinate in principle in "patients with severe allergies". Allergic reactions to vaccines are very rare, but vaccine components are known to cause allergic reactions. BNT162b2 is a vaccine based on an mRNA embedded in lipid nanoparticles and blended with other substances to enable its transport into the cells. In the pivotal phase III clinical trial, the BNT162b2 vaccine was generally well tolerated, but this large clinical trial, used to support vaccine approval by the MHRA and US Food and Drug Administration, excluded individuals with a "history of a severe adverse reaction related to the vaccine and/or a severe allergic reaction (e.g., anaphylaxis) to a component of the study medication". Vaccines are recognized as one of the most effective public health interventions. This repeated administration of a foreign protein (antigen) necessitates a careful allergological history before each application and diagnostic clarification and a risk-benefit assessment before each injection. Severe allergic reactions to vaccines are rare but can be life-threatening, and it is prudent to raise awareness of this hazard among vaccination teams and to take adequate precautions while more experience is gained with this new vaccine.

The LOFAR Two-meter Sky Survey: Deep Fields Data Release 1 - III. Host-galaxy identifications and value added catalogues

Abstract: We present the source associations, cross-identifications, and multi-wavelength properties of the faint radio source population detected in the deep tier of the LOFAR Two Metre Sky Survey (LoTSS): the LoTSS Deep Fields. The first LoTSS Deep Fields data release consists of deep radio imaging at 150~MHz of the ELAIS-N1, Lockman Hole, and Bo\"{o}tes fields, down to RMS sensitives of around 20, 22, and 32$~\mu$Jy\,beam$^{-1}$, respectively. These fields are some of the best studied extra-galactic fields in the northern sky, with existing deep, wide-area panchromatic photometry from X-ray to infrared wavelengths, covering a total of $\approx$~26~\mbox{deg$^{2}$}. We first generated improved multi-wavelength catalogues in ELAIS-N1 and Lockman Hole; combined with the existing catalogue for Bo\"{o}tes, we present forced, matched aperture photometry for over 7.2 million sources across the three fields. We identified multi-wavelength counterparts to the radio detected sources, using a combination of the Likelihood Ratio method and visual classification, which greatly enhances the scientific potential of radio surveys and allows for the characterisation of the photometric redshifts and the physical properties of the host galaxies. The final radio-optical cross-matched catalogue consists of 81\,951 radio-detected sources, with counterparts identified and multi-wavelength properties presented for 79\,820 ($>$97\%) sources. We also examine the properties of the host galaxies, and through stacking analysis find that the radio population with no identified counterpart is likely dominated by AGN at $z\sim3-4$. This dataset contains one of the largest samples of radio-selected star-forming galaxies and active galactic nuclei (AGN) at these depths, making it ideal for studying the history of star-formation, and the evolution of galaxies and AGN across cosmic time.

High quality genome sequences of thirteen Hypoxylaceae (Ascomycota) strengthen the phylogenetic family backbone and enable the discovery of new taxa

Abstract: The Hypoxylaceae (Xylariales, Ascomycota) is a diverse family of mainly saprotrophic fungi, which commonly occur in angiosperm-dominated forests around the world. Despite their importance in forest and plant ecology as well as a prolific source of secondary metabolites and enzymes, genome sequences of related taxa are scarce and usually derived from environmental isolates. To address this lack of knowledge thirteen taxonomically well-defined representatives of the family and one member of the closely related Xylariaceae were genome sequenced using combinations of Illumina and Oxford nanopore technologies or PacBio sequencing. The workflow leads to high quality draft genome sequences with an average N50 of 3.0 Mbp. A backbone phylogenomic tree was calculated based on the amino acid sequences of 4912 core genes reflecting the current accepted taxonomic concept of the Hypoxylaceae. A Percentage of Conserved Proteins (POCP) analysis revealed that 70% of the proteins are conserved within the family, a value with potential application for the definition of family boundaries within the order Xylariales. Also, Hypomontagnella spongiphila is proposed as a new marine derived lineage of Hypom. monticulosa based on in-depth genomic comparison and morphological differences of the cultures. The results showed that both species share 95% of their genes corresponding to more than 700 strain-specific proteins. This difference is not reflected by standard taxonomic assessments (morphology of sexual and asexual morph, chemotaxonomy, phylogeny), preventing species delimitation based on traditional concepts. Genetic changes are likely to be the result of environmental adaptations and selective pressure, the driving force of speciation. These data provide an important starting point for the establishment of a stable phylogeny of the Xylariales; they enable studies on evolution, ecological behavior and biosynthesis of natural products; and they significantly advance the taxonomy of fungi.

Poor nutritional condition promotes high-risk behaviours: a systematic review and meta-analysis.

Abstract: Animal behaviour can lead to varying levels of risk, and an individual's physical condition can alter the potential costs and benefits of undertaking risky behaviours. How risk-taking behaviour depends on condition is subject to contrasting hypotheses. The asset protection principle proposes that individuals in better condition should be more risk averse, as they have higher future reproductive potential (i.e. more to lose). The state-dependent safety hypothesis proposes that high-condition individuals that are more likely to survive and maximise the benefits of risky situations may make apparently riskier choices, as their individual risk is in fact lower. We systematically searched for studies that experimentally manipulated animals' nutritional or energetic condition through diet treatments, and subsequently measured risk-taking behaviour in contexts relating to predation, novelty and exploration. Our meta-analysis quantified condition effects on risk-taking behaviour at both the mean and variance level. We preregistered our methods and hypotheses prior to conducting the study. Phylogenetic multilevel meta-analysis revealed that the lower-nutritional-condition individuals showed on average ca. 26% greater tendency towards risk than high-condition individuals (95% confidence interval: 15-38%; N = 126 studies, 1297 effect sizes). Meta-regressions revealed several factors influencing the overall effect, such as the experimental context used to measure risk-taking behaviour, and the life stage when condition was manipulated. Meta-analysis of variance revealed no clear overall effect of condition on behavioural variance (on average ca. 3% decrease in variance in low- versus high-condition groups; 95% confidence interval: -8 to 3%; N = 119 studies, 1235 effect sizes), however, the experimental context was an important factor influencing the strength and direction of the variance effect. Our comprehensive systematic review and meta-analysis provide insights into the roles of state dependency and plasticity in intraspecific behavioural variation. While heterogeneity among effect sizes was high, our results show that poor nutritional state on average increases risk taking in ecological contexts involving predation, novelty and exploration.

Well-posedness of distribution dependent SDEs with singular drifts

Abstract: Consider the following distribution dependent SDE: dXt=σt(Xt,μXt)dWt+bt(Xt,μXt)dt, where μXt stands for the distribution of Xt. In this paper for non-degenerate σ, we show the strong well-posedness of the above SDE under some integrability assumptions in the spatial variable and Lipschitz continuity in μ about b and σ. In particular, we extend the results of Krylov–Rockner (Probab. Theory Related Fields 131 (2005) 154–196) to the distribution dependent case.

COVID-19 in Germany and China: mitigation versus elimination strategy.

Abstract: Background: The COVID-19 pandemic shows variable dynamics in WHO Regions, with lowest disease burden in the Western-Pacific Region. While China has been able to rapidly eliminate transmission of SARS-CoV-2, Germany - as well as most of Europe and the Americas - is struggling with high numbers of cases and deaths. Objective: We analyse COVID-19 epidemiology and control strategies in China and in Germany, two countries which have chosen profoundly different approaches to deal with the epidemic. Methods: In this narrative review, we searched the literature from 1 December 2019, to 4 December 2020. Results: China and several neighbours (e.g. Australia, Japan, South Korea, New Zealand, Thailand) have achieved COVID-19 elimination or sustained low case numbers. This can be attributed to: (1) experience with previous coronavirus outbreaks; (2) classification of SARS-CoV-2 in the highest risk category and consequent early employment of aggressive control measures; (3) mandatory isolation of cases and contacts in institutions; (4) broad employment of modern contact tracking technology; (5) travel restrictions to prevent SARS-CoV-2 re-importation; (6) cohesive communities with varying levels of social control. Conclusions: Early implementation of intense and sustained control measures is key to achieving a near normal social and economic life.

Water activity in Venus's uninhabitable clouds and other planetary atmospheres

Abstract: The recent suggestion of phosphine in Venus’s atmosphere has regenerated interest in the idea of life in clouds. However, such analyses usually neglect the role of water activity, which is a measure of the relative availability of water, in habitability. Here we compute the water activity within the clouds of Venus and other Solar System planets from observations of temperature and water-vapour abundance. We find water-activity values of sulfuric acid droplets, which constitute the bulk of Venus’s clouds, of ≤0.004, two orders of magnitude below the 0.585 limit for known extremophiles. Considering other planets, ice formation on Mars imposes a water activity of ≤0.537, slightly below the habitable range, whereas conditions are biologically permissive (>0.585) at Jupiter’s clouds (although other factors such as their composition may play a role in limiting their habitability). By way of comparison, Earth’s troposphere conditions are, in general, biologically permissive, whereas the atmosphere becomes too dry for active life above the middle stratosphere. The approach used in the current study can also be applied to extrasolar planets. Calculations of water activity reveal that this parameter can be a substantial barrier to habitability for clouds of Solar System planets. In particular, water activity within droplets of Venus’s clouds is more than 100-fold below the threshold for biotic activity of known extremophiles.

Resistance in repressive contexts: A comprehensive test of psychological predictors.

Abstract: Empirical research on the social psychological antecedents of collective action has been conducted almost exclusively in democratic societies, where activism is relatively safe. The present research examines the psychological predictors of collective action intentions in contexts where resistance is met with significant repression by the authorities. Combining recent advancements in the collective action literature, our model examines the unique predictive roles of emotion (anger and fear), political identity consolidation and participative efficacies, politicized identification, and moral obligation, over and above past participation. It further investigates how these variables are shaped by perceptions of risks attributable to repression. Four survey studies test this model among protesters in Russia (N = 305), Ukraine (N = 136), Hong Kong (N = 115), and Turkey (N = 296). Meta-analytic integration of the findings highlights that, unlike in most current accounts of collective action, protesters in these contexts are not primarily driven by political efficacy. Rather, their involvement is contingent upon beliefs in the ability of protest to build a movement (identity consolidation and participative efficacies) and motivated by outrage at state repression, identification with the social movement, and a sense of moral obligation to act on their behalf. Results also confirm that risks attributable to state repression spur rather than quell resistance by increasing outrage, politicized identification, identity consolidation and participative efficacies, and moral obligation. The implications of these findings for models of collective action and our understanding of the motives underlying engagement in repressive contexts are discussed. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Drought and crop yield.

Abstract: Episodes of water shortage occur in most agricultural regions of the world. Their durations and intensities increase, and their seasonal timing alters with changing climate. During the ontogenic cycle of crop plants, each development stage, such as seed germination, seedling establishment, vegetative root and shoot growth, flowering, pollination and seed and fruit development, is specifically sensitive to dehydration. Desiccation threatens yield and leads to specific patterns, depending on the type of crop plant and the harvested plant parts, e.g. leafy vegetables, tubers, tap roots or fruits. This review summarizes the effects of drought stress on crop plants and relates the dehydration-dependent yield penalty to the harvested organ and tissue. The control of shoot transpiration and the reorganization of root architecture are of core importance for maintaining proper plant water relationships. Upon dehydration, the provision and partitioning of assimilates and the uptake and distribution of nutrients define remaining growth activity. Domestication of crops by selection for high yield under high input has restricted the genetic repertoire for achieving drought stress tolerance. Introgression of suitable alleles from wild relatives into commercial cultivars might improve the ability to grow with less water. Future research activities should focus more on field studies in order to generate more realistic improvements to crops. Robotic field phenotyping should be integrated into genetic mapping for the identification of relevant traits.