473 research outputs found

    The Grothendieck Group of a Quantum Projective Space Bundle

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    We compute the Grothendieck group K_0 of non-commutative analogues of quantum projective space bundles. Our results specialize to give the Grothendieck groups of non-commutative analogues of projective spaces, and specialize to recover the Grothendieck group of a usual projective space bundle over a regular noetherian separated scheme. As an application we develop an intersection theory for the quantum ruled surfaces defined by Van den Bergh.Comment: This paper is being replaced so I can correct the metadata, the title! I (Paul) spelled Grothendieck's name incorrectly. The paper is being reposted with the journal reference and doi added to the metadat

    Analyzing a Bose polaron across resonant interactions

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    Recently, two independent experiments reported the observation of long-lived polarons in a Bose-Einstein condensate, providing an excellent setting to study the generic scenario of a mobile impurity interacting with a quantum reservoir. Here, we expand the experimental analysis by disentangling the effects of trap inhomogeneities and the many-body continuum in one of these experiments. This makes it possible to extract the energy of the polaron at a well-defined density as a function of the interaction strength. Comparisons with quantum Monte-Carlo as well as diagrammatic calculations show good agreement, and provide a more detailed picture of the polaron properties at stronger interactions than previously possible. Moreover, we develop a semi-classical theory for the motional dynamics and three-body loss of the polarons, which partly explains a previously unresolved discrepancy between theory and experimental observations for repulsive interactions. Finally, we utilize quantum Monte-Carlo calculations to demonstrate that the findings reported in the two experiments are consistent with each other

    MicroRNA-204-5p modulates mitochondrial biogenesis in C2C12 myotubes and associates with oxidative capacity in humans

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    Using an unbiased high-throughput microRNA (miRNA)-silencing screen combined with functional readouts for mitochondrial oxidative capacity in C2C12 myocytes, we previously identified 19 miRNAs as putative regulators of skeletal muscle mitochondrial metabolism. In the current study, we highlight miRNA-204-5p, identified from this screen, and further studied its role in the regulation of skeletal muscle mitochondrial function. Following silencing of miRNA-204-5p in C2C12 myotubes, gene and protein expression were assessed using quantitative polymerase chain reaction, microarray analysis, and western blot analysis, while morphological changes were studied by confocal microscopy. In addition, miRNA-204-5p expression was quantified in human skeletal muscle biopsies and associated with in vivo mitochondrial oxidative capacity. Transcript levels of PGC-1α (3.71-fold; p <.01), predicted as an miR-204-5p target, as well as mitochondrial DNA copy number (p <.05) and citrate synthase activity (p =.06) were increased upon miRNA-204-5p silencing in C2C12 myotubes. Silencing of miRNA-204-5p further resulted in morphological changes, induced gene expression of autophagy marker light chain 3 protein b (LC3B; q =.05), and reduced expression of the mitophagy marker FUNDC1 (q =.01). Confocal imaging revealed colocalization between the autophagosome marker LC3B and the mitochondrial marker OxPhos upon miRNA-204-5p silencing. Finally, miRNA-204-5p was differentially expressed in human subjects displaying large variation in oxidative capacity and its expression levels associated with in vivo measures of skeletal muscle mitochondrial function. In summary, silencing of miRNA-204-5p in C2C12 myotubes stimulated mitochondrial biogenesis, impacted on cellular morphology, and altered expression of markers related to autophagy and mitophagy. The association between miRNA-204-5p and in vivo mitochondrial function in human skeletal muscle further identifies miRNA-204-5p as an interesting modulator of skeletal muscle mitochondrial metabolism.</p

    Child rights during the COVID-19 pandemic : learning from child health-and-rights professionals across the World

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    The COVID-19 pandemic underscores the importance of a child rights-based approach to policymaking and crisis management. Anchored in the United Nations Convention on the Rights of the Child, the 3P framework—provision, protection, and participation—forms the foundation for health professionals advocating for children’s rights. Expanding it with two additional domains—preparation and power—into a 5P framework has the potential to enhance child rights-based policies in times of crisis and future pandemics. The study aimed to (1) gather perspectives from child health-and-rights specialists on how children’s rights were highlighted during the early phase of the pandemic in their respective settings; and (2) evaluate the usefulness of the 5P framework in assessing children’s visibility and rights. A qualitative survey was distributed among child health-and-rights professionals; a total of 68 responses were analysed in Atlas.ti 9 from a multi-disciplinary group of policymakers and front-line professionals in eight world regions. As framed by the 5Ps, children’s rights were generally not safeguarded in the initial pandemic response and negatively impacted children’s health and wellbeing. Further, children lacked meaningful opportunities to raise their concerns to policymakers. The 5P framework holds the potential to shape an ethical child rights-based decision-making framework for future crises, both nationally and globally

    OGLE-2005-BLG-018: Characterization of Full Physical and Orbital Parameters of a Gravitational Binary Lens

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    We present the analysis result of a gravitational binary-lensing event OGLE-2005-BLG-018. The light curve of the event is characterized by 2 adjacent strong features and a single weak feature separated from the strong features. The light curve exhibits noticeable deviations from the best-fit model based on standard binary parameters. To explain the deviation, we test models including various higher-order effects of the motions of the observer, source, and lens. From this, we find that it is necessary to account for the orbital motion of the lens in describing the light curve. From modeling of the light curve considering the parallax effect and Keplerian orbital motion, we are able to measure not only the physical parameters but also a complete orbital solution of the lens system. It is found that the event was produced by a binary lens located in the Galactic bulge with a distance 6.7±0.36.7\pm 0.3 kpc from the Earth. The individual lens components with masses 0.9±0.3 M0.9\pm 0.3\ M_\odot and 0.5±0.1 M0.5\pm 0.1\ M_\odot are separated with a semi-major axis of a=2.5±1.0a=2.5 \pm 1.0 AU and orbiting each other with a period P=3.1±1.3P=3.1 \pm 1.3 yr. The event demonstrates that it is possible to extract detailed information about binary lens systems from well-resolved lensing light curves.Comment: 19 pages, 6 figure

    Per and polyfluorinated substances in the Nordic Countries:Use, occurence and toxicology

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    This Tema Nord report presents a study based on open information and custom market research to review the most common perfluorinated substances (PFC) with less focus on PFOS and PFOA.The study includes three major parts: 1) Identification of relevant per-and polyfluorinated substances and their use in various industrial sectors in the Nordic market by interviews with major players and database information. 2) Emissions to and occurence in the Nordic environment of the substances described in 1). 3) A summary of knowledge of the toxic effects on humans and the environment of substances prioritized in 2). There is a lack of physical chemical data, analystical reference substances, human and environmental occurrence and toxicology data, as well as market information regarding PFCs other than PFOA and PFOS and the current legislation cannot enforce disclosure of specific PFC substance information

    Total costs and benefits of biomass in selected regions of the European Union

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    The paper describes results of the BioCosts project in which a comprehensive analysis of the economic and environmental performance of the energy use of biomass was carried out for selected existing facilities throughout the European Union. It is demonstrated that the appropriately organized use of biofuels has significant environmental advantages compared to the use of fossil fuels. Mitigation of global warming is the largest single incentive to use biofuels. However, only a few technologies are economically competitive under prevailing conditions, while others lead to up to 100% higher energy production costs than fossil fuels. Employment effects of using biofuels are small but positive.http://www.sciencedirect.com/science/article/B6V2S-41JM99D-4/1/514a3253589af4590f84544e2966bcb

    Robust Phase Behavior of Model Transient networks

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    In order to study the viscoelastic properties of certain complex fluids which are described in terms of a multiconnected transient network we have developed a convenient model system composed of microemulsion droplets linked by telechelic polymers. The phase behavior of such systems has two characteristic features: a large monophasic region which consists of two sub-regions (a fluid sol phase and a viscoelastic gel phase) separated by a percolation line and a two phase region at low volume fraction with separation into a dilute sol phase and a concentrated gel phase. From the plausible origin of these features we expect them to be very similar in different systems. We describe here the phase behavior of four different systems we prepared in order to vary the time scale of the dynamical response of the transient network; they consist of the combination of two oil(decane) in water microemulsions differing by the stabilizing surfactant monolayer (Cetyl pyridinium chloride/octanol or TX100/TX35) and of two telechelic polymers which are end-grafted poly (ethylene oxide) chains, differing by the end-grafted hydrophobic aliphatic chains (C12H25 or C18H37).Comment: April 9 200

    Subordinated masculinities : A critical inquiry into reproduction of gender norms in handovers and rounds in a forensic psychiatric care

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    Aims and objectives To examine how gendered discursive norms and notions of masculinity are (re)produced in professional conversations about men cared for as patients in forensic psychiatric care, with a particular focus on the centrality of language and gender. Background During verbal handovers and ward rounds, care staff converse to share information about patients and make decisions about their mental status. Spoken language is thus a pivotal tool in verbal handovers and ward rounds, one able to reproduce discourses and gender norms. Design Qualitative. Data collected from audio recordings of verbal handovers and ward rounds in a forensic psychiatric clinic were subjected to discourse analysis. The COREQ checklist was used. Results While discussing patients, staff subordinated them by reproducing a discourse typical of heteronormative, family-oriented care. The overarching discourse, which we labelledsubordinated masculinities, was supported by three other discourses:being unable to take responsibility,being drug-addictedandperforming masculinity. Such discourse was identified as a disciplining practice that subordinate's patients as a means to maintain order, rules and gender norms. Conclusion The study reveals a caring practice that position male patients as children or disabled individuals and, in that way, as subordinated other men within a context were staff reproduces a heteronormative family structured care. The process also reveals a practice were downplaying aggressive and deviant behaviour could disempower and reduce patients ' responsibility for personal actions and their possibilities to participate in their care. That finding especially seems to contradict previous findings that patients want to be able to act responsibly and, to that end, want care staff to help them. Relevance to clinical practice Nurses need to deepen their understanding of how language (re)produces discursive norms of gender and masculinity in forensic care and that process's consequences for such care.Peer reviewe
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