135 research outputs found

    Periodic-orbit theory of universal level correlations in quantum chaos

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    Using Gutzwiller's semiclassical periodic-orbit theory we demonstrate universal behaviour of the two-point correlator of the density of levels for quantum systems whose classical limit is fully chaotic. We go beyond previous work in establishing the full correlator such that its Fourier transform, the spectral form factor, is determined for all times, below and above the Heisenberg time. We cover dynamics with and without time reversal invariance (from the orthogonal and unitary symmetry classes). A key step in our reasoning is to sum the periodic-orbit expansion in terms of a matrix integral, like the one known from the sigma model of random-matrix theory.Comment: 44 pages, 11 figures, changed title; final version published in New J. Phys. + additional appendices B-F not included in the journal versio

    Defects in Regulation of Local Immune Responses Resulting in Atherosclerosis

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    Atherosclerosis is nowadays generally accepted as an inflammatory disease but the mechanism of its origin and development have not yet been fully clarified. The present review focuses on the role of the local immune system as one of the key players in the pathogenesis of the complex process. Its part represented by vascular-associated lymphoid tissue (VALT) within the arterial wall participates directly in the vascular wall's homeostatis. Its inordinate activation during ontogenic development of an individual, this formerly defensive and physiologic mechanism transform into a pathological process resulting in an impairing inflammation. Hsp60, CRP and oxidized or otherwise modified LDL are serious candidates for triggering these pathological changes. The principal role is played by anti-Hsp60 antibodies and by shear stress originating on the surface of endothelium due to blood flow. The experimental and clinical data supporting this immunological hypothesis of atherosclerosis are discussed

    Climate-sensitive health priorities in Nunatsiavut, Canada

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    Background: This exploratory study used participatory methods to identify, characterize, and rank climate-sensitive health priorities in Nunatsiavut, Labrador, Canada. Methods: A mixed method study design was used and involved collecting both qualitative and quantitative data at regional, community, and individual levels. In-depth interviews with regional health representatives were conducted throughout Nunatsiavut (n = 11). In addition, three PhotoVoice workshops were held with Rigolet community members (n = 11), where participants took photos of areas, items, or concepts that expressed how climate change is impacting their health. The workshop groups shared their photographs, discussed the stories and messages behind them, and then grouped photos into re-occurring themes. Two community surveys were administered in Rigolet to capture data on observed climatic and environmental changes in the area, and perceived impacts on health, wellbeing, and lifestyles (n = 187). Results: Climate-sensitive health pathways were described in terms of inter-relationships between environmental and social determinants of Inuit health. The climate-sensitive health priorities for the region included food security, water security, mental health and wellbeing, new hazards and safety concerns, and health services and delivery. Conclusions: The results highlight several climate-sensitive health priorities that are specific to the Nunatsiavut region, and suggest approaching health research and adaptation planning from an EcoHealth perspective

    Levers and leverage points for pathways to sustainability

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    Humanity is on a deeply unsustainable trajectory. We are exceeding planetary boundaries and unlikely to meet many international sustainable development goals and global environmental targets. Until recently, there was no broadly accepted framework of interventions that could ignite the transformations needed to achieve these desired targets and goals. As a component of the IPBES Global Assessment, we conducted an iterative expert deliberation process with an extensive review of scenarios and pathways to sustainability, including the broader literature on indirect drivers, social change and sustainability transformation. We asked, what are the most important elements of pathways to sustainability? Applying a social–ecological systems lens, we identified eight priority points for intervention (leverage points) and five overarching strategic actions and priority interventions (levers), which appear to be key to societal transformation. The eight leverage points are: (1) Visions of a good life, (2) Total consumption and waste, (3) Latent values of responsibility, (4) Inequalities, (5) Justice and inclusion in conservation, (6) Externalities from trade and other telecouplings, (7) Responsible technology, innovation and investment, and (8) Education and knowledge generation and sharing. The five intertwined levers can be applied across the eight leverage points and more broadly. These include: (A) Incentives and capacity building, (B) Coordination across sectors and jurisdictions, (C) Pre-emptive action, (D) Adaptive decision-making and (E) Environmental law and implementation. The levers and leverage points are all non-substitutable, and each enables others, likely leading to synergistic benefits. Transformative change towards sustainable pathways requires more than a simple scaling-up of sustainability initiatives—it entails addressing these levers and leverage points to change the fabric of legal, political, economic and other social systems. These levers and leverage points build upon those approved within the Global Assessment's Summary for Policymakers, with the aim of enabling leaders in government, business, civil society and academia to spark transformative changes towards a more just and sustainable world. A free Plain Language Summary can be found within the Supporting Information of this article.Fil: Chan, Kai M. A.. University of British Columbia; CanadáFil: Boyd, David R.. University of British Columbia; CanadáFil: Gould, Rachelle. University of Vermont; Estados UnidosFil: Jetzkowitz, Jens. Staatliches Museum fur Naturkunde Stuttgart; AlemaniaFil: Liu, Jianguo. Michigan State University; Estados UnidosFil: Muraca, Bárbara. University of Oregon; Estados UnidosFil: Naidoo, Robin. University of British Columbia; CanadáFil: Beck, Paige. University of British Columbia; CanadáFil: Satterfield, Terre. University of British Columbia; CanadáFil: Selomane, Odirilwe. Stellenbosch University; SudáfricaFil: Singh, Gerald G.. University of British Columbia; CanadáFil: Sumaila, Rashid. University of British Columbia; CanadáFil: Ngo, Hien T.. Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services; AlemaniaFil: Boedhihartono, Agni Klintuni. University of British Columbia; CanadáFil: Agard, John. The University Of The West Indies; Trinidad y TobagoFil: de Aguiar, Ana Paula D.. Stockholms Universitet; SueciaFil: Armenteras, Dolors. Universidad Nacional de Colombia; ColombiaFil: Balint, Lenke. BirdLife International; Reino UnidoFil: Barrington-Leigh, Christopher. Mcgill University; CanadáFil: Cheung, William W. L.. University of British Columbia; CanadáFil: Díaz, Sandra Myrna. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Driscoll, John. University of British Columbia; CanadáFil: Esler, Karen. Stellenbosch University; SudáfricaFil: Eyster, Harold. University of British Columbia; CanadáFil: Gregr, Edward J.. University of British Columbia; CanadáFil: Hashimoto, Shizuka. The University Of Tokyo; JapónFil: Hernández Pedraza, Gladys Cecilia. The World Economy Research Center; CubaFil: Hickler, Thomas. Goethe Universitat Frankfurt; AlemaniaFil: Kok, Marcel. PBL Netherlands Environmental Assessment Agency; Países BajosFil: Lazarova, Tanya. PBL Netherlands Environmental Assessment Agency; Países BajosFil: Mohamed, Assem A. A.. Central Laboratory for Agricultural Climate; EgiptoFil: Murray-Hudson, Mike. University Of Botswana; BotsuanaFil: O'Farrell, Patrick. University of Cape Town; SudáfricaFil: Palomo, Ignacio. Basque Centre for Climate Change; EspañaFil: Saysel, Ali Kerem. Boğaziçi University; TurquíaFil: Seppelt, Ralf. Martin-universität Halle-wittenberg; AlemaniaFil: Settele, Josef. German Centre for Integrative Biodiversity Research-iDiv; AlemaniaFil: Strassburg, Bernardo. International Institute for Sustainability, Estrada Dona Castorina; BrasilFil: Xue, Dayuan. Minzu University Of China; ChinaFil: Brondízio, Eduardo S.. Indiana University; Estados Unido

    Calf health from birth to weaning. III. housing and management of calf pneumonia

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    Calfhood diseases have a major impact on the economic viability of cattle operations. A three part review series has been developed focusing on calf health from birth to weaning. In this paper, the last of the three part series, we review disease prevention and management with particular reference to pneumonia, focusing primarily on the pre-weaned calf. Pneumonia in recently weaned suckler calves is also considered, where the key risk factors are related to the time of weaning. Weaning of the suckler calf is often combined with additional stressors including a change in nutrition, environmental change, transport and painful husbandry procedures (castration, dehorning). The reduction of the cumulative effects of these multiple stressors around the time of weaning together with vaccination programmes (preconditioning) can reduce subsequent morbidity and mortality in the feedlot. In most studies, calves housed individually and calves housed outdoors with shelter, are associated with decreased risk of disease. Even though it poses greater management challenges, successful group housing of calves is possible. Special emphasis should be given to equal age groups and to keeping groups stable once they are formed. The management of pneumonia in calves is reliant on a sound understanding of aetiology, relevant risk factors, and of effective approaches to diagnosis and treatment. Early signs of pneumonia include increased respiratory rate and fever, followed by depression. The single most important factor determining the success of therapy in calves with pneumonia is early onset of treatment, and subsequent adequate duration of treatment. The efficacy and economical viability of vaccination against respiratory disease in calves remains unclear

    Evolution of the B3 DNA Binding Superfamily: New Insights into REM Family Gene Diversification

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    Background: The B3 DNA binding domain includes five families: auxin response factor (ARF), abscisic acid-insensitive3 (ABI3), high level expression of sugar inducible (HSI), related to ABI3/VP1 (RAV) and reproductive meristem (REM). The release of the complete genomes of the angiosperm eudicots Arabidopsis thaliana and Populus trichocarpa, the monocot Orysa sativa, the bryophyte Physcomitrella patens,the green algae Chlamydomonas reinhardtii and Volvox carteri and the red algae Cyanidioschyzon melorae provided an exceptional opportunity to study the evolution of this superfamily. Methodology: In order to better understand the origin and the diversification of B3 domains in plants, we combined comparative phylogenetic analysis with exon/intron structure and duplication events. In addition, we investigated the conservation and divergence of the B3 domain during the origin and evolution of each family. Conclusions: Our data indicate that showed that the B3 containing genes have undergone extensive duplication events, and that the REM family B3 domain has a highly diverged DNA binding. Our results also indicate that the founding member of the B3 gene family is likely to be similar to the ABI3/HSI genes found in C. reinhardtii and V. carteri. Among the B3 families, ABI3, HSI, RAV and ARF are most structurally conserved, whereas the REM family has experienced a rapid divergence. Thes

    Calf health from birth to weaning. I. General aspects of disease prevention

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    Calfhood diseases have a major impact on the economic viability of cattle operations. This is the first in a three part review series on calf health from birth to weaning, focusing on preventive measures. The review considers both pre- and periparturient management factors influencing calf health, colostrum management in beef and dairy calves and further nutrition and weaning in dairy calves
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