194 research outputs found
Ist Außenwirtschaftstheorie genderblind?:Ein Beitrag zu Gender in der Makroökonomik
Gemäß der konventionellen Außenwirtschaftslehre ist der Abbau von Handelshemmnissen als positiv zu beurteilen, da die Aufnahme von freiem, grenzüberschreitendem Handel die ökonomische Wohlfahrt aller daran beteiligten Länder erhöht. Die Außenhandelstheorie gilt generell als geschlechtsneutral. Dies ist allerdings zu hinterfragen, da Studien existieren, die einen Zusammenhang zwischen internationalem Handel und Geschlechterverhältnissen belegen. Mittels einer geschlechtersensiblen Analyse der Außenhandelstheorien von Ricardo und Heckscher-Ohlin wird untersucht, ob die theoretische Basis der Außenwirtschaftslehre tatsächlich geschlechtsneutral oder nicht vielmehr geschlechterblind ist
Bdellovibrio and Like Organisms Are Predictors of Microbiome Diversity in Distinct Host Groups
Biodiversity is generally believed to be a main determinant of ecosystem functioning. This principle also applies to the microbiome and could consequently contribute to host health. According to ecological theory, communities are shaped by top predators whose direct and indirect interactions with community members cause stability and diversity. Bdellovibrio and like organisms (BALOs) are a neglected group of predatory bacteria that feed on Gram-negative bacteria and can thereby influence microbiome composition. We asked whether BALOs can predict biodiversity levels in microbiomes from distinct host groups and environments. We demonstrate that genetic signatures of BALOs are commonly found within the 16S rRNA reads from diverse host taxa. In many cases, their presence, abundance, and especially richness are positively correlated with overall microbiome diversity. Our findings suggest that BALOs can act as drivers of microbial alpha-diversity and should therefore be considered candidates for the restoration of microbiomes and the prevention of dysbiosis
Perpendicular exchange bias in antiferromagnetic-ferromagnetic nanostructures
This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.Exchange bias effects have been induced along the perpendicular-to-film direction in nanostructures prepared by electron beamlithography, consisting of a ferromagnetic [Pt/Co] multilayer exchange coupled to an antiferromagnet (FeMn). As a general trend, the exchange bias field and the blocking temperature decrease, whereas the coercivity increases, as the size of the nanostructures is reduced
The Role of DNA Methylation in Genome Defense in Cnidaria and Other Invertebrates
Considerable attention has recently been focused on the potential involvement of DNA methylation in regulating gene expression in cnidarians. Much of this work has been centered on corals, in the context of changes in methylation perhaps facilitating adaptation to higher seawater temperatures and other stressful conditions. Although first proposed more than 30 years ago, the possibility that DNA methylation systems function in protecting animal genomes against the harmful effects of transposon activity has largely been ignored since that time. Here, we show that transposons are specifically targeted by the DNA methylation system in cnidarians, and that the youngest transposons (i.e., those most likely to be active) are most highly methylated. Transposons in longer and highly active genes were preferentially methylated and, as transposons aged, methylation levels declined, reducing the potentially harmful side effects of CpG methylation. In Cnidaria and a range of other invertebrates, correlation between the overall extent of methylation and transposon content was strongly supported. Present transposon burden is the dominant factor in determining overall level of genomic methylation in a range of animals that diverged in or before the early Cambrian, suggesting that genome defense represents the ancestral role of CpG methylation
Carrying Capacity and Colonization Dynamics of Curvibacter in the Hydra Host Habitat
Most eukaryotic species are colonized by a microbial community – the microbiota – that is acquired during early life stages and is critical to host development and health. Much research has focused on the microbiota biodiversity during the host life, however, empirical data on the basic ecological principles that govern microbiota assembly is lacking. Here we quantify the contribution of colonizer order, arrival time and colonization history to microbiota assembly on a host. We established the freshwater polyp Hydra vulgaris and its dominant colonizer Curvibacter as a model system that enables the visualization and quantification of colonizer population size at the single cell resolution, in vivo, in real time. We estimate the carrying capacity of a single Hydra polyp as 2 × 105 Curvibacter cells, which is robust among individuals and time. Colonization experiments reveal a clear priority effect of first colonizers that depends on arrival time and colonization history. First arriving colonizers achieve a numerical advantage over secondary colonizers within a short time lag of 24 h. Furthermore, colonizers primed for the Hydra habitat achieve a numerical advantage in the absence of a time lag. These results follow the theoretical expectations for any bacterial habitat with a finite carrying capacity. Thus, Hydra colonization and succession processes are largely determined by the habitat occupancy over time and Curvibacter colonization history. Our experiments provide empirical data on the basic steps of host-associated microbiota establishment – the colonization stage. The presented approach supplies a framework for studying habitat characteristics and colonization dynamics within the host–microbe setting
Novel HBsAg markers tightly correlate with occult HBV infection and strongly affect HBsAg detection.
Occult HBV infection (OBI) is a threat for the safety of blood-supply, and has been associated with the onset of HBV-related hepatocellular carcinoma and lymphomagenesis. Nevertheless, genetic markers in HBsAg (particularly in D-genotype, the most common in Europe) significantly associated with OBI in vivo are missing. Thus, the goal of this study is to define: (i) prevalence and clinical profile of OBI among blood-donors; (ii) HBsAg-mutations associated with OBI; (iii) their impact on HBsAg-detection. OBI was searched among 422,278 blood-donors screened by Nucleic-Acid-Testing. Following Taormina-OBI-definition, 26 (0.006%) OBI-patients were identified. Despite viremia <50IU/ml, HBsAg-sequences were obtained for 25/26 patients (24/25 genotype-D). OBI-associated mutations were identified by comparing OBI-HBsAg with that of 82 chronically-infected (genotype-D) patients as control. Twenty HBsAg-mutations significantly correlated for the first time with OBI. By structural analysis, they localized in the major HBV B-cell-epitope, and in HBsAg-capsid interaction region. 14/24 OBI-patients (58.8%) carried in median 3 such mutations (IQR:2.0-6.0) against 0 in chronically-infected patients. By co-variation analysis, correlations were observed for R122P+S167L (phi=0.68, P=0.01), T116N+S143L (phi=0.53, P=0.03), and Y100S+S143L (phi=0.67, p<0.001). Mutants (obtained by site-directed mutagenesis) carrying T116N, T116N+S143L, R122P, R122P+Q101R, or R122P+S167L strongly decreased HBsAg-reactivity (54.9±22.6S/CO, 31.2±12.0S/CO, 6.1±2.4S/CO, 3.0±1.0S/CO and 3.9±1.3S/CO, respectively) compared to wild-type (306.8±64.1S/CO). Even more, Y100S and Y100S+S143L supernatants show no detectable-HBsAg (experiments in quadruplicate). In conclusions, unique HBsAg-mutations in genotype-D, different than those described in genotypes B/C (rarely found in western countries), tightly correlate with OBI, and strongly affect HBsAg-detection. By altering HBV-antigenicity and/or viral-particle maturation, they may affect full-reliability of universal diagnostic-assays for HBsAg-detection
Group trust dynamics during a risky driving experience in a Tesla Model X
The growing concern about the risk and safety of autonomous vehicles (AVs) has made it vital to understand driver trust and behavior when operating AVs. While research has uncovered human factors and design issues based on individual driver performance, there remains a lack of insight into how trust in automation evolves in groups of people who face risk and uncertainty while traveling in AVs. To this end, we conducted a naturalistic experiment with groups of participants who were encouraged to engage in conversation while riding a Tesla Model X on campus roads. Our methodology was uniquely suited to uncover these issues through naturalistic interaction by groups in the face of a risky driving context. Conversations were analyzed, revealing several themes pertaining to trust in automation: (1) collective risk perception, (2) experimenting with automation, (3) group sense-making, (4) human-automation interaction issues, and (5) benefits of automation. Our findings highlight the untested and experimental nature of AVs and confirm serious concerns about the safety and readiness of this technology for on-road use. The process of determining appropriate trust and reliance in AVs will therefore be essential for drivers and passengers to ensure the safe use of this experimental and continuously changing technology. Revealing insights into social group–vehicle interaction, our results speak to the potential dangers and ethical challenges with AVs as well as provide theoretical insights on group trust processes with advanced technology
C14ORF39/SIX6OS1 is a constituent of the synaptonemal complex and is essential for mouse fertility
Meiotic recombination generates crossovers between homologous chromosomes that are essential for genome haploidization. The synaptonemal complex is a ‘zipper’-like protein assembly that synapses homologue pairs together and provides the structural framework for
processing recombination sites into crossovers. Humans show individual differences in the number of crossovers generated across the genome. Recently, an anonymous gene variant in C14ORF39/SIX6OS1 was identified that influences the recombination rate in humans. Here
we show that C14ORF39/SIX6OS1 encodes a component of the central element of the synaptonemal complex. Yeast two-hybrid analysis reveals that SIX6OS1 interacts with the well-established protein synaptonemal complex central element 1 (SYCE1). Mice lacking SIX6OS1 are defective in chromosome synapsis at meiotic prophase I, which provokes
an arrest at the pachytene-like stage and results in infertility. In accordance with its role as a modifier of the human recombination rate, SIX6OS1 is essential for the appropriate processing of intermediate recombination nodules before crossover formation.This work was supported by BFU_2014-59307-R, MEIONet and JCyLe (CSI052U16). LGH and NFM are supported by European Social Fund/JCyLe grants (EDU/1083/2013 and EDU/310/2015). ORD is a Sir Henry Dale Fellow jointly funded by the Wellcome Trust and Royal Society (Grant Number 104158/Z/14/Z). RB is funded by DFG (grant Be1168/8-1). AT and ID were supported by DFG grants TO421/8-2 and TO421/6-1, respectively.Peer reviewe
Anti-HBV treatment induces novel reverse transcriptase mutations with reflective effect on HBV S antigen
The identification of novel reverse-transcriptase (RT) drug-resistance mutations is critical in predicting the probability of success to anti-HBV treatment. Furthermore, due to HBV-RT/HBsAg gene-overlap, they can have an impact on HBsAg-detection and quantification
Traffic-related pollution (NO2 and CO) and its association with asthma symptoms among 10-11 year old children in Malaysia
Introduction: Children attending schools located close to major traffic sources are exposed to higher indoor air pollution levels due to infiltration of outdoor air pollutants. This study investigates the respiratory health of Malaysian schoolchildren in relation to indoor air pollution in schools and at home.
Methods: This cross-sectional study was conducted among 2,164 schoolchildren aged 10-11 years in 35 urban and semi-rural schools in Kuala Lumpur Negeri Sembilan. Parents completed the International Study of Asthma and Allergy in Childhood questionnaire and provided information on the home environment and socio demographic background. Concentrations of NO2 and CO were measured indoors and outdoors of 14 schools.
Results: The mean (standard deviation (SD)) indoor exposure to concentrations of air pollutants measured in Malaysian schools were: 42.9 (8.77) μg/m3 of NO2 and 3.16 (2.47) ppm of CO in urban schools and 12.4 (8.79) μg/m3 of NO2 and 0.33 (0.18) ppm of CO respectively for semi-rural schools. The prevalence of asthma was significantly higher among urban compared to semi-rural children. Ever wheeze was more common in urban areas (14.3%) compared to semi-rural areas (10.6%) as was current wheeze (urban 9.1%; semi-rural 6.2%), nocturnal cough (urban 12.0%; semi-rural 7.2%) and most other symptoms. The 3 main predictors of nocturnal cough were the presence of a current smoker at home (OR 1.97; 95% CI: 1.31-2.96), the absence of exhaust system in the kitchen (OR 1.67; 95% CI: 1.03-2.68) and the use of air conditioning (OR 3.10; 95% CI: 1.37-5.71). Self-reported asthma was predicted by the occupation of mothers; managerial positions (OR 1.78; 95% CI: 1.21-2.62), mothers working in the armed forces (OR 1.92; 95% CI: 1.32- 2.78) and fathers with a high school level of education (OR 0.46; 95% CI: 0.26- 0.82) while exposure to SHS of ≥4 hours per day (OR 2.53; 95% CI: 1.55-4.14) explained approximately 6.0% of the likelihood of reporting doctor-diagnosed asthma.
Conclusion: This study has identified that many Malaysian schoolchildren experience exposure to air pollution indoors that exceeds WHO guidance limits for NO2 pollution but did not exceed the RMAQG levels. Considering that traffic-related sources largely contribute towards NO2 concentrations, compliance with the standards is not indicative of the reduced health risks for air pollution exposures
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