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31.
Wildlife crime can be difficult to quantify, and its true impact on populations can be underestimated if rates are under-recorded. The illegal killing of birds of prey is an important form of wildlife crime, which in the UK, is often associated with land managed for the recreational shooting of red grouse Lagopus lagopus scoticus. In the UK, increases in peregrine falcons Falco peregrinus following recovery from organo-chlorine pesticides have not been uniform, with slow growth and localised declines in some areas, including those managed for red grouse shooting. In this study, we combined 1081 peregrine nest histories across northern England between 1980 and 2006 with a remotely sensed map of grouse moor management, to test whether breeding performance was lower in areas with active management for grouse shooting. Productivity of pairs on grouse moors was 50% lower than pairs breeding on non-grouse moor habitat. However, clutch size and brood size of successful nests did not differ between habitat types, suggesting that food constraints were unlikely to explain this difference. Population models suggested source-sink dynamics, with populations on grouse moors unable to sustain themselves without immigration. Population data confirmed that growth rates were indeed lower on grouse moors than on non-grouse moor sites. Analysis of wildlife crime data confirmed that persecution of the species was more frequent on grouse moors than in other habitat types. This population will be more secure, and better able to function as a barometer of environmental health and climate change, if illegal persecution of the species ceases on areas of land managed for grouse shooting.  相似文献   
32.
Although the mammalian immune system is generally thought to develop in a linear fashion, findings in avian and murine species argue instead for the developmentally ordered appearance (or "layering") of distinct hematopoietic stem cells (HSCs) that give rise to distinct lymphocyte lineages at different stages of development. Here we provide evidence of an analogous layered immune system in humans. Our results suggest that fetal and adult T cells are distinct populations that arise from different populations of HSCs that are present at different stages of development. We also provide evidence that the fetal T cell lineage is biased toward immune tolerance. These observations offer a mechanistic explanation for the tolerogenic properties of the developing fetus and for variable degrees of immune responsiveness at birth.  相似文献   
33.
Herbs are a rich source of bioactive phytochemicals such as carotenoids, which are known to exert various positive biological effects. However, there is very limited information in the literature regarding the content and bioavailability of carotenoids from commonly consumed herbs. Therefore, the objectives of the present study were first, to determine the carotenoid content of eight herbs namely basil (Ocimum basilicum), coriander (Coriandrum sativum), dill (Anethum graveolens), mint (Metha L.), parsley (Petroselinum crispum), rosemary (Rosmarinus officinalis), sage (Salvia officinalis), and tarragon (Artemisia dracunculus L.); and second, to assess carotenoid bioaccessibility from these herbs using a simulated human in vitro digestion model. Carotenoid bioaccessibility is defined as the amount of carotenoids transferred to micelles after digestion when compared with the original amount present in the food. The content of individual carotenoids varied significantly among the herbs tested. Carotenoid bioaccessibility varied from 0 to 42.8%. Basil and coriander, and their respective micelles, contained the highest levels of β-carotene, β-cryptoxanthin, and lutein + zeaxanthin. Our findings show that herbs are rich sources of carotenoids and that these foods can significantly contribute to the intake of bioaccessible carotenoids.  相似文献   
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Serological and clinical studies were conducted between March 2009 and August 2010 to validate the foot-and-mouth disease free status of Tsirang district of Bhutan as determined by the country's passive surveillance system. Randomised (first survey) and targeted (third survey) samplings, with subsequent follow-up samplings (second and fourth), were conducted on FMD-susceptible animals to detect the disease at a design prevalence of 25% and 20% at the individual animal-level and village-level, respectively. Sera from cattle, goats, pigs, and sheep were tested for the presence of non-structural protein (NSP) antibodies using two commercial (PrioCHECK(?) FMDV NS and CHEKIT(?)-FMD-3ABC-bo-ov) and one in-house NSP kit (c-ELISA, AAHL, Australia). The overall seropositivity (all species) at the animal-level was 3% (95% CI: 1.7, 4.8) and 3.5% (95% CI: 2.1, 5.4), for the randomised and targeted surveys, respectively. Except for one goat from the first survey, none of the small ruminants and pigs had NSP antibodies. The seropositives from the first and targeted surveys were distributed among 13 and 16 of 20 villages sampled, respectively. All repeat testing from the initial seropositive animals and their herd mates, for both the first and third surveys, were negative in the NSP tests 6-8 months later. Using the hypergeometric exact probability formula for two-stage analyses, the results enabled rejection of the null hypothesis and supported conclusion that the population was free from disease at the minimum expected prevalence of 20% at the 95.53% and 99.46% confidence levels, for the randomised and targeted surveys, respectively. Clinical surveillance also showed absence of disease or clinical signs suggestive of FMD. The few seropositives were likely to be false positives due to factors such as imperfect specificities of the tests and possible NSP-residues in the vaccines. The study has paved the way for initiation of zoning approaches for the progressive control of FMD in Bhutan.  相似文献   
36.
Callus produced from leaves of a Ghanaian strain of the neem tree, Azadirachta indica A. Juss has been shown to produce the natural insecticide azadirachtin when grown in a defined medium. The azadirachtin was isolated by standard procedures of solvent partition and column chromatography monitored by supercritical fluid chromatography. Biological activity was monitored with antifeedant tests using the desert locust (Schistocerca gregaria Forsk.). The azadirachtin was identified by chromatography on three independent chromatographic systems (SFC, HPLC & TLC) and two thin-layer colour tests. It has 100% antifeedant activity at < 0.04mg litre?1. The yield of azadirachtin was 0.0007% based on dry weight of callus.  相似文献   
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38.
Detection, genetic characterization, and control of bovine viral diarrhea virus (BVDV) disease in a large commercial dairy herd is reported. Precolostral BVDV serum antibody was detected in 5.3% (12/226) of newborn calves before the test and removal of persistently infected (PI) animals and in 0.4% (2/450) of newborn calves after the removal of PI heifers.  相似文献   
39.
Methadone is an opioid analgesic in veterinary and human medicine. To help develop appropriate pain management practices and to develop a quantitative model for predicting methadone dosimetry, a flow‐limited multiroute physiologically based pharmacokinetic (PBPK) model for methadone in dogs constructed with Berkeley Madonna? was developed. The model accounts for intravenous (IV), subcutaneous (SC), and oral administrations, and compartmentalizes the body into different components. This model was calibrated from plasma pharmacokinetic data after IV administration of methadone in Beagles and Greyhounds. The calibrated model was evaluated with independent data in both breeds of dogs. One advantage of this model is that most physiological parameter values for Greyhounds were taken directly from the original literature. The developed model simulates available pharmacokinetic data for plasma concentrations well for both breeds. After conducting regression analysis, all simulated datasets produced an R 2 > 0.80 when compared to the measured plasma concentrations. Comparative analysis of the dosimetry of methadone between the breeds suggested that Greyhounds had ~50% lower 24‐hr area under the curve (AUC) of plasma or brain concentrations than in Beagles. Furthermore, population analysis was conducted with this study. This model can be used to predict methadone concentrations in multiple dog breeds using breed‐specific parameters.  相似文献   
40.
A modified version of the model Opus was applied to measurements of soil water dynamics and atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine) persistence in a Bruntwood silt loam soil (Haplic Andosol, FAO system) in Hamilton, New Zealand. The modified model, Opus2, is briefly described and parameter estimation for the simulations is discussed. Soil water dynamics were more accurately described by applying measured soil hydraulic properties than by estimating them using pedotransfer functions. A parameter sensitivity analysis revealed that degradation was the most relevant process in simulating pesticide behaviour by Opus2. The Arrhenius equation incorporated in Opus2 did not correctly describe the effect of temperature on degradation rates obtained at 10, 20 and 30 degrees C. However, as the Arrhenius coefficient is a very sensitive parameter and soil temperature variation was relatively narrow in the field, the Arrhenius coefficient was approximated from the laboratory study. The simulation results obtained were superior to modelling at constant temperature. Field measured persistence of atrazine in the topsoil was underpredicted using the half-life determined in the laboratory at 10 degrees C. Modelling with a lag phase followed by accelerated degradation by use of a sigmoidal degradation equation in Opus2 significantly improved the modelling results. Nevertheless, degradation processes in the laboratory under controlled conditions did not accurately represent field dissipation, however well the laboratory degradation data could be described by simple kinetic equations. The study indicates the importance of improving field techniques for measuring degradation, and developing laboratory protocols that yield degradation data that are more representative of pesticide dynamics in field soils.  相似文献   
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