Experimental infection and pathology of clade 2.2 H5N1 virus in gulls

During 2006, H5N1 HPAI caused an epizootic in wild birds, resulting in a die-off of Laridae in the Novosibirsk region at Chany Lake. In the present study, we infected common gulls (Larus canus) with a high dose of the H5N1 HPAI virus isolated from a common gull to determine if severe disease could be induced over the 28 day experimental period. Moderate clinical signs including diarrhea, conjunctivitis, respiratory distress and neurological signs were observed in virus-inoculated birds, and 50% died. The most common microscopic lesions observed were necrosis of the pancreas, mild encephalitis, mild myocarditis, liver parenchymal hemorrhages, lymphocytic hepatitis, parabronchi lumen hemorrhages and interstitial pneumonia. High viral titers were shed from the oropharyngeal route and virus was still detected in one bird at 25 days after infection. In the cloaca, the virus was detected sporadically in lower titers. The virus was transmitted to direct contact gulls. Thus, infected gulls can pose a significant risk of H5N1 HPAIV transmission to other wild migratory waterfowl and pose a risk to more susceptible poultry species. These findings have important implications regarding the mode of transmission and potential risks of H5N1 HPAI spread by gulls.     

Behavioural diversity in fishing—Towards a next generation of fishery models

Despite improved knowledge and stricter regulations, numerous fish stocks remain overharvested. Previous research has shown that fisheries management may fail when the models and assessments used to inform management are based on unrealistic assumptions regarding fishers' decision‐making and responses to policies. Improving the understanding of fisher behaviour requires addressing its diversity and complexity through the integration of social science knowledge into modelling. In our paper, we review and synthesize state‐of‐the‐art research on both social science's understanding of fisher behaviour and the representation of fisher decision‐making in scientific models. We then develop and experiment with an agent‐based social–ecological fisheries model that formalizes three different fishing styles. Thereby we reflect on the implications of our incorporation of behavioural diversity and contrast it with the predominant assumption in fishery models: fishing practices being driven by rational profit maximizing. We envision a next generation of fisheries models and management that account for social scientific knowledge on individual and collective human behaviours. Through our agent‐based model, we demonstrate how such an integration is possible and propose a scientific approach for reducing uncertainty based on human behavioural diversity in fisheries. This study serves to lay the foundations for a next generation of social–ecological fishery models that account for human behavioural diversity and social and ecological complexity that are relevant for a realistic assessment and management of fishery sustainability problems.     

High Temperature and Humidity Effect on Biochemical Characteristics of Organically-Grown Parsnip Roots Compared to Garlic Bulbs

Plant Foods for Human Nutrition - Functional food with high concentrations of monosaccharides and antioxidants is important for quick replenishment of energy reserves and rehabilitation after...     

Generic indicators for loss of resilience before a tipping point leading to population collapse

Theory predicts that the approach of catastrophic thresholds in natural systems (e.g., ecosystems, the climate) may result in an increasingly slow recovery from small perturbations, a phenomenon called critical slowing down. We used replicate laboratory populations of the budding yeast Saccharomyces cerevisiae for direct observation of critical slowing down before population collapse. We mapped the bifurcation diagram experimentally and found that the populations became more vulnerable to disturbance closer to the tipping point. Fluctuations of population density increased in size and duration near the tipping point, in agreement with the theory. Our results suggest that indicators of critical slowing down can provide advance warning of catastrophic thresholds and loss of resilience in a variety of dynamical systems.     

Fatty acid content and composition in tissues of Baikal grayling (Thymallus baicalensis), with a special focus on DHA synthesis

Long-chain polyunsaturated fatty acids of n-3 family (n-3 LC PUFAs) are physiologically essential compounds required for normal growth and development of animals, including humans. The ability of fish species to synthesize n-3 LC PUFAs varies significantly across different trophic levels. We have studied fatty acid (FA) content (mg/g of wet weight) and level (% of total FAs) in the brain, liver, heart, intestine, female and male gonads, muscle, and adipose tissues of commercially important wild freshwater Baikal grayling. Additionally, FA content and level of Baikal grayling juveniles have been studied. In all tissues of Baikal grayling, some LC PUFAs, namely, 24:5n-3 and 24:6n-3 (C24 PUFAs), have been found. These FAs are the intermediate products in the synthesis of docosahexaenoic acid (DHA, 22:6n-3) by the Sprecher pathway. The levels of C24 PUFAs in tissues differed significantly: the highest levels of C24 PUFAs were found in adipose tissue and the lowest values in the gonads of females, liver, brain, and head of juveniles. According to the dynamics of DHA and C24 PUFAs, the maximum rate of DHA synthesis is achieved in brain of Baikal grayling, while the lowest rate of DHA synthesis probably occurs in adipose tissue. Although all studied tissues had differences in the number of FAs and their levels, 16:0, 18:1n-9, 16:1n-7, 20:5n-3, and DHA dominated. Male gonads contained an extremely high level of furan FAs — presumably beneficial substances for human health. Additionally, the nutritional value of the tissues of Baikal grayling as a source of n-3 LC PUFAs for humans has been estimated.

     

Features of technogenic metal pollution of roadside soil according to x-ray fluorescence monitoring data

X-ray fluorescence monitoring of technogenic metal pollution of Moscow soil near two highways with heavy traffic was fulfilled. As a result of vehicles running, the macro and microelement composition of Moscow roadside soil was seen to substantially differ from the composition of both soddy podzolic soil (typical for Moscow region) and any other soil of the temperate climatic region of Russia. The average Fe, Mn and Ti contents in soil were found to exceed the usual background level by 2–5-fold, maximum Pb content — by 10–15-fold. The lateral and depth distribution of enumerated metal contents in soil near the highways was studied. It was shown that the behavior of lateral pollutant distribution in soil has no specific exponential shape. It has local extremuma and depends on the metal nature and the roadside terrain topography. For Pb — one of the most dangerous pollutants — the mechanism of chemical transformations and the interrelation of the pollutant chemical form, its molecular weight, the dwelling time in atmosphere and the distance to the highway were discussed.     

Potassium placement effect on dynamics of barley (Hordeum vulgare L.) nutrition

The effects of local placement of potassium (K) on mineral nutrition dynamics of barley (Hordeum vulgare L.) in fertile Сhernozem were studied. A pot experiment with local K-placement at 4–5 cm soil depth was carried out and the dynamics of nitrogen, phosphorus, potassium (NPK) concentrations in tillers, organs and parts of spring barley was measured. K-placement increased the productivity index from 0.49 to 0.54, despite optimal and slightly varying NPK concentrations during the second half of the vegetation period (60–100 d). This occurs due to partitioning of assimilates, N, K, and especially P in generative organs of primary and secondary tillers forming quality grains. Nutrient concentrations in certain primary tiller parts of a 60-d plant (senescing leaves and the main spike axis) proved to be more sensitive indicators of the K-placement effect than average whole-plant characteristics. While being beneficial, K-placement had little impact on the overall NPK removal in barley, which shows a significant role of factors related to K uptake kinetics. Thus, the chosen parameters in the soil–plant system (the high content of available K in Chernozem, in the second part of the vegetation period) have for the first time allowed the evaluation of the impact of local K-placement on mineral nutrition dynamics in barley.     

Structure of Rab GDP-dissociation inhibitor in complex with prenylated YPT1 GTPase

Rab/Ypt guanosine triphosphatases (GTPases) represent a family of key membrane traffic regulators in eukaryotic cells whose function is governed by the guanosine diphosphate (GDP) dissociation inhibitor (RabGDI). Using a combination of chemical synthesis and protein engineering, we generated and crystallized the monoprenylated Ypt1:RabGDI complex. The structure of the complex was solved to 1.5 angstrom resolution and provides a structural basis for the ability of RabGDI to inhibit the release of nucleotide by Rab proteins. Isoprenoid binding requires a conformational change that opens a cavity in the hydrophobic core of its domain II. Analysis of the structure provides a molecular basis for understanding a RabGDI mutant that causes mental retardation in humans.