119 research outputs found

    Baroclinic boundary currents with downstream decreasing buoyancy: A study of an idealized Nordic Seas system

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    The dynamics of a baroclinic boundary current losing buoyancy along its path is analyzed both theoretically and using a numerical ocean-circulation model. A fundamental ingredient in our analysis is that the side boundaries of the ocean basin are sloping gently down to the deep ocean. Theoretically we find that the coastal boundary current develops two branches: one seaward baroclinic jetstream and one barotropic current, which is confined to the continental slope. The baroclinic jetstream decreases its transport as the buoyancy is lost from the surface layer. This decrease in transport is compensated by an increase in the barotropic flow on the slope. When the buoyancy is lost altogether, the entire volume transport occurs in the barotropic slope current. In our numerical experiments we focus on the penetration of warm water over a sill into a cold semi-enclosed basin. The flow enters as a baroclinic current with a thickness approximately equal to the sill depth and proceeds around the basin on essentially the same depth while being transformed to a barotropic slope current which leaves the basin over the sill. It should be noted that the circulation does not involve any renewal of the deep water in the cold basin, except in the initial spin up of the system. We suggest that our results can illuminate some basic aspects of the dynamics in the Nordic Seas, which are invaded by North Atlantic surface water over the Greenland-Scotland Ridge. One striking example; is the observations reported by Orvik et al. (2001), which show that the flow of Atlantic water along the Norwegian coast has two branches: A baroclinic jetstream and a shelf-bound barotropic current. The existence of this double-flow structure is to be expected from our theoretical considerations and numerical simulations

    SNX10 gene mutation leading to osteopetrosis with dysfunctional osteoclasts

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    Acknowledgements We sincerely thank the patients and family members who participated in this study. We would also like to thank Stefan Esher, UmeÄ University, for help with genealogy, and Anna Westerlund for excellent technical assistance. This work was supported by grants from the FOU, at the UmeÄ university hospital, and the Medical Faculty at UmeÄ University. The work at University of Gothenburg was supported by grants from The Swedish Research Council, the Swedish Rheumatism Association, the Royal 80-Year Fund of King Gustav V, ALF/LUA research grant from Sahlgrenska University Hospital in Gothenburg and the Lundberg Foundation. The work at the University of Gothenburg and the University of Aberdeen was supported by Euroclast, a Marie Curie FP7-People-2013-ITN: # 607446.Peer reviewedPublisher PD

    AHAA- Agile, Hybrid Assessment Method for Automotive, Safety Critical SMEs

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    The need for software is increasingly growing in the automotive industry. Software development projects are, however, often troubled by time and budget overruns, resulting in systems that do not fulfill customer requirements. Both research and industry lack strategies to combine reducing the long software development lifecycles (as required by time-to-market demands) with increasing the quality of the software developed. Software process improvement (SPI) provides the first step in the move towards software quality, and assessments are a vital part of this process. Unfortunately, software process assessments are often expensive and time consuming. Additionally, they often provide companies with a long list of issues without providing realistic suggestions. The goal of this paper is to describe a new low-overhead assessment method that has been designed specifically for small-to-medium-sized (SMEs) organisations wishing to be automotive software suppliers. This assessment method integrates the structured-ness of the plan-driven SPI models of Capability Maturity Model Integration (CMMI) and Automotive SPICETM with the flexibleness of agile practices

    Spatial and temporal melt variability at Helheim Glacier, East Greenland, and its effect on ice dynamics

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    This is the publisher's version, also available electronically from "http://onlinelibrary.wiley.com".[1] Understanding the behavior of large outlet glaciers draining the Greenland Ice Sheet is critical for assessing the impact of climate change on sea level rise. The flow of marine-terminating outlet glaciers is partly governed by calving-related processes taking place at the terminus but is also influenced by the drainage of surface runoff to the bed through moulins, cracks, and other pathways. To investigate the extent of the latter effect, we develop a distributed surface-energy-balance model for Helheim Glacier, East Greenland, to calculate surface melt and thereby estimate runoff. The model is driven by data from an automatic weather station operated on the glacier during the summers of 2007 and 2008, and calibrated with independent measurements of ablation. Modeled melt varies over the deployment period by as much as 68% relative to the mean, with melt rates approximately 77% higher on the lower reaches of the glacier trunk than on the upper glacier. We compare melt variations during the summer season to estimates of surface velocity derived from global positioning system surveys. Near the front of the glacier, there is a significant correlation (on >95% levels) between variations in runoff (estimated from surface melt) and variations in velocity, with a 1 day delay in velocity relative to melt. Although the velocity changes are small compared to accelerations previously observed following some calving events, our findings suggest that the flow speed of Helheim Glacier is sensitive to changes in runoff. The response is most significant in the heavily crevassed, fast-moving region near the calving front. The delay in the peak of the cross-correlation function implies a transit time of 12–36 h for surface runoff to reach the bed

    Neil3-dependent base excision repair regulates lipid metabolism and prevents atherosclerosis in Apoe-deficient mice

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    Increasing evidence suggests that oxidative DNA damage accumulates in atherosclerosis. Recently, we showed that a genetic variant in the human DNA repair enzyme NEIL3 was associated with increased risk of myocardial infarction. Here, we explored the role of Neil3/NEIL3 in atherogenesis by both clinical and experimental approaches. Human carotid plaques revealed increased NEIL3 mRNA expression which significantly correlated with mRNA levels of the macrophage marker CD68. Apoe−/−Neil3−/− mice on high-fat diet showed accelerated plaque formation as compared to Apoe−/− mice, reflecting an atherogenic lipid profile, increased hepatic triglyceride levels and attenuated macrophage cholesterol efflux capacity. Apoe−/−Neil3−/− mice showed marked alterations in several pathways affecting hepatic lipid metabolism, but no genotypic alterations in genome integrity or genome-wide accumulation of oxidative DNA damage. These results suggest a novel role for the DNA glycosylase Neil3 in atherogenesis in balancing lipid metabolism and macrophage function, potentially independently of genome-wide canonical base excision repair of oxidative DNA damage

    Psycho-social factors associated with mental resilience in the Corona lockdown.

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    The SARS-CoV-2 pandemic is not only a threat to physical health but is also having severe impacts on mental health. Although increases in stress-related symptomatology and other adverse psycho-social outcomes, as well as their most important risk factors have been described, hardly anything is known about potential protective factors. Resilience refers to the maintenance of mental health despite adversity. To gain mechanistic insights about the relationship between described psycho-social resilience factors and resilience specifically in the current crisis, we assessed resilience factors, exposure to Corona crisis-specific and general stressors, as well as internalizing symptoms in a cross-sectional online survey conducted in 24 languages during the most intense phase of the lockdown in Europe (22 March to 19 April) in a convenience sample of N = 15,970 adults. Resilience, as an outcome, was conceptualized as good mental health despite stressor exposure and measured as the inverse residual between actual and predicted symptom total score. Preregistered hypotheses (osf.io/r6btn) were tested with multiple regression models and mediation analyses. Results confirmed our primary hypothesis that positive appraisal style (PAS) is positively associated with resilience (p < 0.0001). The resilience factor PAS also partly mediated the positive association between perceived social support and resilience, and its association with resilience was in turn partly mediated by the ability to easily recover from stress (both p < 0.0001). In comparison with other resilience factors, good stress response recovery and positive appraisal specifically of the consequences of the Corona crisis were the strongest factors. Preregistered exploratory subgroup analyses (osf.io/thka9) showed that all tested resilience factors generalize across major socio-demographic categories. This research identifies modifiable protective factors that can be targeted by public mental health efforts in this and in future pandemics
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