5,994 research outputs found
Liquid drop stability for protein crystal growth in microgravity
It is possible to grow protein crystals for biomedical research in microgravity by deploying a protein-rich solution from a syringe, forming a drop in which crystallization can occur with the proper degree of supersaturation. Drop stability is critical to the success of this research, due to the large drop sizes which can be achieved in space. In order to determine the type of syringe tips most suitable to support these large drops, tests were performed during brief periods of weightlessness onboard the NASA KC-135 low-gravity simulation aircraft. The drops were analyzed using three simple models in which the samples were approximated by modified pendulum and spring systems. It was concluded that the higher frequency systems were the most stable, indicating that of the syringes utilized, a disk-shaped configuration provided the most stable environment of low-gravity protein crystal growth
On inter-organizational trust, control and risk in transboundary fisheries governance
Inter-organizational collaboration is often considered essential to transboundary fishery governance, due, in part, to the high levels of task interdependence, the remote and often treacherous conditions, and the limited levels of information available to any policy actor on resource status. In the high seas, Regional Fisheries Management Organizations (RFMOs) are responsible for sustainably managing highly migratory and straddling fish stocks through the implementation of ecosystem-based approaches and ensuring adequate inter-jurisdictional cooperation. A central question facing RFMO governance is therefore how to structure and sustain inter-organizational transboundary collaboration under high uncertainty? This paper presents the case of the North Atlantic Salmon Conservation Organization (NASCO), conceptualized as a strategic alliance between the bureaucratic organizations responsible for north Atlantic salmon fishery management in the member countries. We identify and explain how dimensions of trust, control, and perceived risk have structured the collaborative performance of the alliance. The application of an integrated trust-control-risk framework increases conceptual clarity for how, when and why alliance managers might seek to develop different forms of trust through different management control systems in ways that further multi-actor collaborative network performance. Future research needs are identified, including better understanding how managerial strategies and control mechanisms facilitate inter-organizational trust in transboundary governance settings and mitigate the perceived risks of working together
Combining the bulk transfer formulation and surface renewal analysis for estimating the sensible heat flux without involving the parameter KB-1
The singleâsource bulk transfer formulation (based on the MoninâObukhov Similarity Theory, MOST) has been used to estimate the sensible heat flux, H, in the framework of remote sensing over homogeneous surfaces (HMOST). The latter involves the canopy parameter, , which is difficult to parameterize. Over short and dense grass at a site influenced by regional advection of sensible heat flux, HMOST with â=â2 (i.e., the value recommended) correlated strongly with the H measured using the Eddy Covariance, EC, method, HEC. However, it overestimated HEC by 50% under stable conditions for samples showing a local air temperature gradient larger than the measurement error, 0.4 kmâ1. Combining MOST and Surface Renewal analysis, three methods of estimating H that avoid dependency have been derived. These new expressions explain the variability of H versus , where is the friction velocity, is the radiometric surface temperature, and is the air temperature at height, z. At two measurement heights, the three methods performed excellently. One of the methods developed required the same readily/commonly available inputs as HMOST due to the fact that the ratio between and the ramp amplitude was found fairly constant under stable and unstable cases. Over homogeneous canopies, at a site influenced by regional advection of sensible heat flux, the methods proposed are an alternative to the traditional bulk transfer method because they are reliable, exempt of calibration against the EC method, and are comparable or identical in cost of application. It is suggested that the methodology may be useful over bare soil and sparse vegetation.This research was funded by CERESS project AGL2011â30498 (Ministerio de EconomĂa y Competitividad of Spain, cofunded FEDER), CGL2012â37416âC04â01 (Ministerio de Ciencia y InnovaciĂłn of Spain), and CEI Iberus, 2014 (Proyecto financiado por el Ministerio de EducaciĂłn en el marco del Programa Campus de Excelencia Internacional of Spain)
Agricultural intensification heightens food safety risks posed by wild birds
Agricultural intensification and simplification are key drivers of recent declines in wild bird populations, heightening the need to better balance conservation with food production. This is hindered, however, by perceptions that birds threaten food safety. While birds are known reservoirs of foodborne pathogens, there remains uncertainty about the links between landscape context, farming practices, and actual crop contamination by birds. Here, we examine relationships between landscape context, farming practices, and pathogen contamination by birds using a barrier-to-spillover approach. First, we censused bird communities using point count surveys. Second, we collected 2,024 faecal samples from captured birds alongside 1,215 faecal samples from brassica fields and food processing areas across 50 farms spanning the USA West Coast. We then estimated the prevalence of three foodborne pathogens across landscape and livestock intensification gradients. Finally, we quantified the number of plants with faeces. Campylobacterspp. were detected in 10.2% of faeces from captured birds and 13.1% of faeces from production areas. Non-native birds were 4.1 times more likely to haveCampylobacterspp. than native birds.Salmonellaspp. were detected in 0.2% of faeces from production areas and were never detected in captured birds. We detected evidence of Shiga toxigenicE. coliin one sample across the >3,200 tested. Campylobacterspp. prevalence in faeces from production areas increased with increasing mammalian livestock densities in the landscape but decreased with increasing amounts of natural habitat. We encountered bird faeces on 3.3% of plants examined. Despite the impact on pathogen prevalence, amount of natural habitat in the landscape did not increase the number of plants with bird faeces, although on-farm mammalian livestock density slightly did. Synthesis and applications. Food safety and wildlife conservation are often thought to be in conflict. However, our findings suggest that natural habitat around farms may reduce crop contamination rates by birds. This is perhaps because natural habitat can promote native birds that are less likely to harbour foodborne pathogens or because it decreases contact with livestock waste. Our results suggest that preservation of natural habitats around farms could benefit both conservation and food safety, contrary to current standards for 'best practices'
The psychiatric phenotypes of 1q21 distal deletion and duplication
Copy number variants are amongst the most highly penetrant risk factors for psychopathology and neurodevelopmental deficits, but little information about the detailed clinical phenotype associated with particular variants is available. We present the largest study of the microdeletion and -duplication at the distal 1q21 locus, which has been associated with schizophrenia and intellectual disability, in order to investigate the range of psychiatric phenotypes. Clinical and cognitive data from 68 deletion and 55 duplication carriers were analysed with logistic regression analysis to compare frequencies of mental disorders between carrier groups and controls, and linear mixed models to compare quantitative phenotypes. Both children and adults with copy number variants at 1q21 had high frequencies of psychopathology. In the children, neurodevelopmental disorders were most prominent (56% for deletion, 68% for duplication carriers). Adults had increased prevalence of mood (35% for deletion [ORâ=â6.6 (95% CI: 1.4-40.1)], 55% for duplication carriers [8.3 (1.4-55.5)]) and anxiety disorders (24% [1.8 (0.4-8.4)] and 55% [10.0 (1.9-71.2)]). The adult group, which included mainly genetically affected parents of probands, had an IQ in the normal range. These results confirm high prevalence of neurodevelopmental disorders associated with CNVs at 1q21 but also reveal high prevalence of mood and anxiety disorders in a high-functioning adult group with these CNVs. Because carriers of neurodevelopmental CNVs who show relevant psychopathology but no major cognitive impairment are not currently routinely receiving clinical genetic services widening of genetic testing in psychiatry may be considered
The psychiatric phenotypes of 1q21 distal deletion and duplication
Copy number variants are amongst the most highly penetrant risk factors for psychopathology and neurodevelopmental deficits, but little information about the detailed clinical phenotype associated with particular variants is available. We present the largest study of the microdeletion and -duplication at the distal 1q21 locus, which has been associated with schizophrenia and intellectual disability, in order to investigate the range of psychiatric phenotypes. Clinical and cognitive data from 68 deletion and 55 duplication carriers were analysed with logistic regression analysis to compare frequencies of mental disorders between carrier groups and controls, and linear mixed models to compare quantitative phenotypes. Both children and adults with copy number variants at 1q21 had high frequencies of psychopathology. In the children, neurodevelopmental disorders were most prominent (56% for deletion, 68% for duplication carriers). Adults had increased prevalence of mood (35% for deletion [ORâ=â6.6 (95% CI: 1.4-40.1)], 55% for duplication carriers [8.3 (1.4-55.5)]) and anxiety disorders (24% [1.8 (0.4-8.4)] and 55% [10.0 (1.9-71.2)]). The adult group, which included mainly genetically affected parents of probands, had an IQ in the normal range. These results confirm high prevalence of neurodevelopmental disorders associated with CNVs at 1q21 but also reveal high prevalence of mood and anxiety disorders in a high-functioning adult group with these CNVs. Because carriers of neurodevelopmental CNVs who show relevant psychopathology but no major cognitive impairment are not currently routinely receiving clinical genetic services widening of genetic testing in psychiatry may be considered
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