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R. G. Vergel L. R. Sanchez B. L. Heredero P. L. Rodriguez A. J. Martinez 《黑龙江环境通报》1990,10(3):149-152
Folic acid (5 mg) was given daily, for not less than one menstrual period before conception and until the tenth week of pregnancy, to 81 women (FS) with a history of a previous neural tube defect (NTD) birth. There was no NTD recurrence among this group or among the offspring of a further 20 women (PS) whose folic acid supplementation fell short of the full regime. In another 114 women who became pregnant without folic acid supplementation (US), there were four NTD recurrences (3.5 per cent). Our results suggest that folic acid supplementation might be an effective method of primary prevention of neural tube defects. 相似文献
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Scott?NunesEmail author Eva-Maria?Muecke Zaira?Sanchez Rebekah?R.?Hoffmeier Lesley?T.?Lancaster 《Behavioral ecology and sociobiology》2004,56(2):97-105
We evaluated the relationship between play behavior and motor development in juvenile Beldings ground squirrels (Spermophilus beldingi). We observed the social play behavior of juvenile S. beldingi during their primary play period and conducted motor skills tests at the beginning and end of the play period. We also placed different-sized boxes in juveniles natal areas during the play period and observed box climbing behavior to assess the difficulty of non-social play tasks undertaken by juveniles. Rates of social play were greater in heavy compared to light individuals, supporting the idea that juveniles must selectively allocate available energy among competing demands such as growth and play behavior. Juveniles played almost exclusively with littermates; however, they did not play at equal rates with all partners. Rather, they tended to have one preferred partner and to devote significantly less time to playing with each additional partner, indicating that stability and familiarity are important in social play interactions. Motor skill levels at the end of the play period were greater among juveniles who played with many compared to few partners, suggesting that exposure to a variety of play interactions helps facilitate motor development. Improvement in motor skills was greater among juveniles who played at high compared to low rates, had several compared to few male play partners, and engaged in several compared to few play bouts with male partners, suggesting that elements of play with male partners prominently influence motor development. The partner with whom males played at the highest rate tended to be male, and rates of social play were highest in male biased litters, raising the possibility that improvement in motor proficiency arising from play with males may be especially important for young males. The size of experimental boxes that juveniles climbed increased during the play period, supporting the idea that individuals choose play tasks that pose the greatest challenge.Communicated by T. Czeschlik 相似文献
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Key studies supported by species-level data collection have provided early indications of the potential implications of unmitigated change for the ecosystems and biodiversity of southern Africa. These suggest a significant threat to biodiversity, both from changing bioclimatic suitability and changing atmospheric CO2 level that seems to affect the competitive balance between woody and herbaceous plants in the dominant savanna biome of this region. Modeling efforts suggest significant implications of unmitigated climate change for this region, but assumptions underpinning methods such as bioclimatic modeling must be recognized, some of which might lead to over estimates of the rate and extent of the potential impacts. General trends and level of coincidence between various types of studies do support a high degree of concern for a substantial portion of southern African biodiversity under unmitigated climate-change scenarios. The most significant changes in ecosystem structure (both increases and decreases in woody plant cover), and associated faunal diversity changes, are projected in the dominant savanna vegetation type in this region, while the most significant biodiversity loss is projected for the winter rainfall region. Follow-up work to detect early signs of climate change identify regions of high- and low-potential impacts, and experimental work to test some important hypotheses relating to the future evolution of climate-change impacts across the region are very few and urgently required. 相似文献
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Plant-trait-based modeling assessment of ecosystem-service sensitivity to land-use change 总被引:1,自引:0,他引:1
Fabien Quétier Sandra Lavorel Wilfried Thuiller Ian Davies 《Ecological applications》2007,17(8):2377-2386
Evidence is accumulating that the continued provision of essential ecosystem services is vulnerable to land-use change. Yet, we lack a strong scientific basis for this vulnerability as the processes that drive ecosystem-service delivery often remain unclear. In this paper, we use plant traits to assess ecosystem-service sensitivity to land-use change in subalpine grasslands. We use a trait-based plant classification (plant functional types, PFTs) in a landscape modeling platform to model community dynamics under contrasting but internally consistent land-use change scenarios. We then use predictive models of relevant ecosystem attributes, based on quantitative plant traits, to make projections of ecosystem-service delivery. We show that plant traits and PFTs are effective predictors of relevant ecosystem attributes for a range of ecosystem services including provisioning (fodder), cultural (land stewardship), regulating (landslide and avalanche risk), and supporting services (plant diversity). By analyzing the relative effects of the physical environment and land use on relevant ecosystem attributes, we also show that these ecosystem services are most sensitive to changes in grassland management, supporting current agri-environmental policies aimed at maintaining mowing of subalpine grasslands in Europe. 相似文献
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Marc-Antoine Sanchez Simon-Pierre Corcostégui Charles-Arnaud De Broucker Olivier Cabre Stéphanie Watier-Grillot Sylvie Perelle Katia Ambert-Balay Vincent Pommier de Santi 《Food and environmental virology》2017,9(2):234-237
In February 2016, an outbreak of gastroenteritis occurred in a French military unit located in Poitiers, France. Attack rate was of 34% (103/300). A case–control study identified association between illness and cake consumption. Stool samples were tested positive for Norovirus GII.17 for one patient and one post-symptomatic food worker (FW). The FW presented vomiting one day before cake preparation. The NoV strain was probably spread through food worker hand contact. Prevention of Norovirus foodborne outbreaks implies new guidelines for FWs management in France and Europe. 相似文献
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We explored the effects of prevalence, latitudinal range and clumping (spatial autocorrelation) of species distribution patterns on the predictive accuracy of eight state-of-the-art modelling techniques: Generalized Linear Models (GLMs), Generalized Boosting Method (GBM), Generalized Additive Models (GAMs), Classification Tree Analysis (CTA), Artificial Neural Network (ANN), Multivariate Adaptive Regression Splines (MARS), Mixture Discriminant Analysis (MDA) and Random Forest (RF). One hundred species of Lepidoptera, selected from the Distribution Atlas of European Butterflies, and three climate variables were used to determine the bioclimatic envelope for each butterfly species. The data set consisting of 2620 grid squares 30′ × 60′ in size all over Europe was randomly split into the calibration and the evaluation data sets. The performance of different models was assessed using the area under the curve (AUC) of a receiver operating characteristic (ROC) plot. Observed differences in modelling accuracy among species were then related to the geographical attributes of the species using GAM. The modelling performance was negatively related to the latitudinal range and prevalence, whereas the effect of spatial autocorrelation on prediction accuracy depended on the modelling technique. These three geographical attributes accounted for 19–61% of the variation in the modelling accuracy. Predictive accuracy of GAM, GLM and MDA was highly influenced by the three geographical attributes, whereas RF, ANN and GBM were moderately, and MARS and CTA only slightly affected. The contrasting effects of geographical distribution of species on predictive performance of different modelling techniques represent one source of uncertainty in species spatial distribution models. This should be taken into account in biogeographical modelling studies and assessments of climate change impacts. 相似文献