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991.
We describe the discovery of polymorphisms in the Cryptosporidium oocyst wall protein (COWP) gene conferring a novel restriction fragment length polymorphism (RFLP) pattern in 26/60 (43%) isolates from a flock of sheep sampled following a waterborne outbreak of human cryptosporidiosis. The sheep isolates showed identical PCR-RFLP patterns to each other by COWP genotyping but different from those of most currently recognised genotypes, including the major Cryptosporidium parvum genotypes 1 and 2. Sequence analysis of the 550bp amplicon from the COWP gene was compared with a DNA coding region employed in previous studies and showed the novel isolate to differ from other Cryptosporidium species and C. parvum isolates by 7-21%. The sheep-derived isolates were compared at this and further three Cryptosporidium gene loci with isolates from other farmed animals. The loci employed were one in the thrombospondin related adhesive protein (TRAP-C2) gene and two in the 70kDa heat shock protein (HSP70) gene (CPHSP1 and 2). Other animal samples tested in our laboratory were from clinically ill animals and all contained C. parvum genotype 2. The sheep in which the novel isolate was identified were healthy and showed no symptoms of cryptosporidiosis, and the novel sheep isolate could represent a non-pathogenic strain. Our studies suggest that a previously undetected Cryptosporidium sub-type may exist in sheep populations, reflecting the increasingly recognised diversity within the parasite genus.  相似文献   
992.
Understanding the ecology of large ungulates in southern Africa requires accurate and precise measures of population size. Recovery or exploitation of ungulates in reserves is currently instigated when population size changes exceed 15% per annum, but monitoring is usually undertaken with single counts from helicopters, for which precision and the power to detect change are untested. In essence, power being the strength of a monitoring result in showing change over time. Retrospective power analysis is a useful technique to investigate the variability of single‐count aerial surveys. Using replicated helicopter‐based counts of southern African ungulates and post hoc analysis, we investigated the power of currently used single‐count surveys across five common ungulate species and 11 wildlife reserves. We expected high variability in count data and set α = 0.1 and 0.2 (α being the type I error rate), and asked two questions: ‘How much does power vary in replicated aerial counts of southern African wildlife across reserves and species?’ and ‘Can current single‐count aerial surveys detect population changes in response to management actions or are the statistical errors intractable?’ Single counts were mostly unreliable; only one of 42 had sufficient power to detect meaningful changes in population size or their trends at α = 0.1, and only three had sufficient power at α = 0.2. Power varied widely according to species (e.g. warthog, median power at α = 0.1; 0.12–0.37: blue wildebeest, median power at α = 0.1; 0.23–0.74), and, within species, between replicates and reserves. Our retrospective calculations demonstrated insensitivity and ineffectiveness in most currently applied single counts from helicopters. Consequently, it is impossible to interpret the effects of ungulate conservation actions on many southern African reserves. Retrospective power analyses enables determination of which previous aerial surveys were useful for population assessment and adaptive management, and which should be discarded. We recommend that prospective power analyses are undertaken to determine future helicopter survey sample size and replication requirements, especially in small reserves.  相似文献   
993.
Pine martens (Martes martes) are subject to national and international conservation legislation throughout most of their European range. Yet population density and abundance estimates, which are a key component of effective conservation management, are lacking in many countries. In this study, a large-scale non-invasive survey was undertaken in 14 forested study sites throughout Ireland to assess variation in pine marten density and abundance. Pine marten hair samples were collected in each study site and analysed using genetic techniques to determine individual identity data. Density and abundance estimates were obtained using spatially explicit capture-recapture models and CAPWIRE. Across all study sites, a total of 93 individual pine marten were identified and captured 217 times. Estimated pine marten density varied from 0 to 2.60 individuals per km2 of forested habitat, with all but a single site having estimated densities of ≤1 pine marten per km2 of forest habitat. Mean population abundance estimates across all study sites ranged from 0 to 27 individuals. Spatially explicit capture-recapture models on combined data across all 14 study sites provided a mean density estimate of 0.64 (95% CI 0.49–0.81). Combining this with data on the current distribution and estimated area of forest habitat occupied by the species in Ireland, the total pine marten population abundance of pine marten in Ireland was estimated at 3043 (95% CI 2330–3852) individuals. This research has conducted the largest scale investigation of pine marten density and abundance in any part of its global distribution and provided an improved basis for future population assessment and monitoring of this species.  相似文献   
994.
995.
Predicting how environmental factors affect the distribution of species is a fundamental goal of conservation biology. Conservation biologists rely on species distribution and abundance models to identify key habitat characteristics for species. Occupancy modeling is frequently promoted as a practical alternative to use of abundance in identifying habitat quality. While occupancy and abundance are potentially governed by different limiting factors operating at different scales, few studies have directly compared predictive models for these approaches in the same system. We evaluated how much occupancy and abundance are driven by the same environmental factors for a species of conservation concern, the greater short‐horned lizard (Phrynosoma hernandesi). Occupancy was most strongly dictated by precipitation, temperature, and density of ant mounds. While these factors were also in the best‐supported predictive models for lizard abundance, the magnitude of the effects varied, with the sign of the effect changing for temperature and precipitation. These discrepancies show that while occupancy modeling can be an efficient approach for conservation planning, predictors of occupancy probability should not automatically be equated with predictors of population abundance. Understanding the differences in factors that control occupancy versus abundance can help us to identify habitat requirements and mitigate the loss of threatened species.  相似文献   
996.
Transient gene expression in mammalian cells is an efficient process for producing recombinant proteins for various research applications to support large molecule therapeutics development. For the first time, we report a high throughput small molecule (SM) screen to identify novel compounds that increase antibody titers after polyethylenimine (PEI) transient transfection of a HEK293 cell line. After screening 31,413 SMs in a 50 μL scaled‐down process, we validated 164 SMs to improve yields by up to twofold. The titer increase mediated by the SMs varied for different antibodies. SM dose optimizations resulted in almost threefold higher titers. The top 2, structurally distinct SM hits, increased antibody titers more than twofold in a 1 mL production process. Averaged across three antibodies of different expression levels, the compounds enhanced transient productivity by ~80%. Intriguingly, both compounds arrested cells in the G2/M cell cycle phase leading to a decrease in growth and nutrient consumption, while elevating titer, nuclear plasmid DNA (pDNA) copy numbers, and mRNA levels. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 3:1579–1588, 2017  相似文献   
997.
The various problems associated with treating sulphate-containing wastewaters stem inherently from successful competitive interactions between sulphate reducing bacteria (SRB) and other bacteria involved in the process, resulting in the formation of H2S. Prevention of in-reactor sulphide generation by use of specific SRB inhibitors presents a potential solution. Nitrite has been reported to be a specific inhibitor of SRB but its possible toxicity to syntrophic and methanogenic members of the anaerobic consortium has not been investigated. In batch activity and toxicity tests, under both mesophilic and thermophilic conditions, nitrite, at concentrations of up to 150 mg L–1, was found to be ineffective as a specific inhibitor of SRB, and was also shown to have an inhibitory effect on the activity of syntrophic and methane-producing bacteria in mesophilic and thermophilic digester sludge samples.  相似文献   
998.
999.
Objective To identify risk factors in early life (up to 3 years of age) for obesity in children in the United Kingdom.Design Prospective cohort study.Setting Avon longitudinal study of parents and children, United Kingdom.Participants 8234 children in cohort aged 7 years and a subsample of 909 children (children in focus) with data on additional early growth related risk factors for obesity.Main outcome measures Obesity at age 7 years, defined as a body mass index 3 95th centile relative to reference data for the UK population in 1990.Results Eight of 25 putative risk factors were associated with a risk of obesity in the final models: parental obesity (both parents: adjusted odds ratio, 10.44, 95% confidence interval 5.11 to 21.32), very early (by 43 months) body mass index or adiposity rebound (15.00, 5.32 to 42.30), more than eight hours spent watching television per week at age 3 years (1.55, 1.13 to 2.12), catch-up growth (2.60, 1.09 to 6.16), standard deviation score for weight at age 8 months (3.13, 1.43 to 6.85) and 18 months (2.65, 1.25 to 5.59); weight gain in first year (1.06, 1.02 to 1.10 per 100 g increase); birth weight, per 100 g (1.05, 1.03 to 1.07); and short (< 10.5 hours) sleep duration at age 3 years (1.45, 1.10 to 1.89).Conclusion Eight factors in early life are associated with an increased risk of obesity in childhood.  相似文献   
1000.
The anti-proliferative activity of acylated heterocyclic sulfonamides is described in Vascular Endothelial Growth Factor-dependent Human Umbilical Vascular Endothelial Cells (VEGF-HUVEC) and in HCT116 tumor cells in a soft agar diffusion assay.  相似文献   
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