186 research outputs found

    Evaluation of Cathode Gas Composition and Temperature Influences on Alkaline Anion Exchange Membrane Fuel Cell (AAEMFC) Performance

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    The effects of different temperatures (55, 65, 75 and 85 °C) and cathode gas compositions (O2, synthetic air, air and 90% synthetic air+10% CO2) on alkaline anion exchange membrane fuel cell (AAEMFC) were evaluated. Membrane electrode assemblies (MEA) were fabricated using commercial anion exchange membrane (AEM) in OH- form and Pt catalyst. Polarization curves and voltage responses during constant current were performed in order to describe the influences of temperature and gas composition on the AAEMFC performance. The experimental results showed that the fuel cell performance increases with elevating temperatures for all applied gas compositions. Highest power density of 34.7 mW cm-2 was achieved for pure O2 as cathode feed. A decrease to 20.3 mW cm-2 was observed when cathode gas composition was changed to synthetic air due to reduction of the O2 partial pressure. The presence of CO2 in atmospheric air applied to the cathode stream caused a further drop of the maximum power density to 15.2 mW cm-2 driven by neutralization of OH- ions with CO2

    Network e-Volution

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    Modern society is a network society permeated by information technology (IT). As a result of innovations in IT, enormous amounts of information can be communicated to a larger number of recipients faster than ever before. The evolution of networks is heavily influenced by the extensive use of IT, which has enabled co-evolving advanced quantitative and qualitative forms of networking. Although several networks have been formed with the aim to reduce or deal with uncertainty through faster and broader access to information, it is in fact IT that has created new kinds of uncertainty. For instance, although digital information integration in supply chains has made production planning more robust, it has at the same time intensified mutual dependencies, thereby actually increasing the level of uncertainty. The aim of this working paper is to investigate the aspects of evolving networks and uncertainty in networks at the cutting edges of different types of networks and from the perspective of different layers defining these networks

    Cryo-electron microscopy reveals two distinct type IV pili assembled by the same bacterium

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    Type IV pili are flexible filaments on the surface of bacteria, consisting of a helical assembly of pilin proteins. They are involved in bacterial motility (twitching), surface adhesion, biofilm formation and DNA uptake (natural transformation). Here, we use cryo-electron microscopy and mass spectrometry to show that the bacterium Thermus thermophilus produces two forms of type IV pilus ('wide' and 'narrow'), differing in structure and protein composition. Wide pili are composed of the major pilin PilA4, while narrow pili are composed of a so-far uncharacterized pilin which we name PilA5. Functional experiments indicate that PilA4 is required for natural transformation, while PilA5 is important for twitching motility. Type IV pili are flexible filaments on the surface of bacteria, consisting of a helical assembly of pilin proteins. Here, Neuhaus et al. show that the bacterium Thermus thermophilus produces two forms of type IV pilus, differing in structure, protein composition, and function.Peer reviewe

    How Do Honeybees Attract Nestmates Using Waggle Dances in Dark and Noisy Hives?

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    It is well known that honeybees share information related to food sources with nestmates using a dance language that is representative of symbolic communication among non-primates. Some honeybee species engage in visually apparent behavior, walking in a figure-eight pattern inside their dark hives. It has been suggested that sounds play an important role in this dance language, even though a variety of wing vibration sounds are produced by honeybee behaviors in hives. It has been shown that dances emit sounds primarily at about 250–300 Hz, which is in the same frequency range as honeybees' flight sounds. Thus the exact mechanism whereby honeybees attract nestmates using waggle dances in such a dark and noisy hive is as yet unclear. In this study, we used a flight simulator in which honeybees were attached to a torque meter in order to analyze the component of bees' orienting response caused only by sounds, and not by odor or by vibrations sensed by their legs. We showed using single sound localization that honeybees preferred sounds around 265 Hz. Furthermore, according to sound discrimination tests using sounds of the same frequency, honeybees preferred rhythmic sounds. Our results demonstrate that frequency and rhythmic components play a complementary role in localizing dance sounds. Dance sounds were presumably developed to share information in a dark and noisy environment

    One dimensional magnetism in synthetic Pauflerite, ÎČ\beta-VOSO4_4

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    We have synthesized single-crystal samples of ÎČ\beta-VOSO4_4 and fully characterized their magnetic properties. Our magnetic susceptibility, high field magnetization and powder inelastic neutron scattering results are in excellent agreement with theoretical expressions for a one-dimensional spin-1/2 Heisenberg chain with an exchange parameter of 3.83(2)3.83(2)\,meV. Ab-initio calculations identify the superexchange pathway, revealing that the spin-chain does not run along the expected crystallographic chain aa-direction but instead between V4+^{4+}O6_{6} octahedra that are linked via SO4_{4} tetrahedra along the bb-axis. We do not detect any phase transition to a long-range magnetic order within our experimental conditions, indicating ÎČ\beta-VOSO4_4 is very close to an ideal one-dimensional magnetic system

    NGS-guided precision oncology in metastatic breast and gynecological cancer: first experiences at the CCC Munich LMU

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    PURPOSE Comprehensive genomic profiling identifying actionable molecular alterations aims to enable personalized treatment for cancer patients. The purpose of this analysis was to retrospectively assess the impact of personalized recommendations made by a multidisciplinary tumor board (MTB) on the outcome of patients with breast or gynecological cancers, who had progressed under standard treatment. Here, first experiences of our Comprehensive Cancer Center Molecular Tumor Board are reported. METHODS All patients were part of a prospective local registry. 95 patients diagnosed with metastatic breast cancer or gynecological malignancies underwent extended molecular profiling. From May 2017 through March 2019, the MTB reviewed all clinical cases considering tumor profile and evaluated molecular alterations regarding further diagnostic and therapeutic recommendations. RESULTS 95 patients with metastatic breast or gynecological cancers were discussed in the MTB (68% breast cancer, 20% ovarian cancer, 5% cervical cancer, 3% endometrial cancer and 4% others). Genes with highest mutation rate were PIK3CA and ERBB2. Overall, 34 patients (36%) received a biomarker-based targeted therapy recommendation. Therapeutic recommendations were implemented in nine cases; four patients experienced clinical benefit with a partial response or disease stabilization lasting over 4~months. CONCLUSION In the setting of a multidisciplinary molecular tumor board, a small but clinically meaningful group of breast and gynecological cancer patients benefits from comprehensive genomic profiling. Broad and successful implementation of precision medicine is complicated by patient referral at late stage disease and limited access to targeted agents and early clinical trials. TRIAL REGISTRATION NUMBER 284-10 (03.05.2018)

    Humiliated fury is not universal: the co-occurrence of anger and shame in the United States and Japan

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    It has been widely believed that individuals transform high-intensity shame into anger because shame is unbearably painful. This phenomenon was first coined “humiliated fury,” and it has since received empirical support. The current research tests the novel hypothesis that shame-related anger is not universal, yet hinges on the cultural meanings of anger and shame. Two studies compared the occurrence of shamerelated anger in North American cultural contexts (where shame is devalued and anger is valued) to its occurrence in Japanese contexts (where shame is valued and anger is devalued). In a daily-diary study, participants rated anger and shame feelings during shame situations that occurred over one week. In a vignette study, participants rated anger and shame in response to standardised shame vignettes that were generated in previous research by either U.S. or Japanese respondents. Across the two studies, and in line with previous research on humiliated fury, shame predicted anger for U.S. participants. Yet, neither in the daily diary study nor for the Japanese-origin vignettes, did we find shame-related anger in Japanese participants. Only when presented with U.S.-origin vignettes, did Japanese respondents in the vignette study report shame-related anger. The findings suggest that shame-related anger is a culture-specific phenomenon

    Psychological well-being in Europe after the outbreak of war in Ukraine

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    The Russian invasion of Ukraine on February 24, 2022, has had devastating effects on the Ukrainian population and the global economy, environment, and political order. However, little is known about the psychological states surrounding the outbreak of war, particularly the mental well-being of individuals outside Ukraine. Here, we present a longitudinal experience-sampling study of a convenience sample from 17 European countries (total participants = 1,341, total assessments = 44,894, countries with >100 participants = 5) that allows us to track well-being levels across countries during the weeks surrounding the outbreak of war. Our data show a significant decline in well-being on the day of the Russian invasion. Recovery over the following weeks was associated with an individual’s personality but was not statistically significantly associated with their age, gender, subjective social status, and political orientation. In general, well-being was lower on days when the war was more salient on social media. Our results demonstrate the need to consider the psychological implications of the Russo-Ukrainian war next to its humanitarian, economic, and ecological consequences
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