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991.
992.
Grace E. Vincent Brad Aisbett Sarah J. Hall Sally A. Ferguson 《Chronobiology international》2016,33(6):657-666
ABSTRACTPlanned burning is a preventative strategy aimed at decreasing fuel loads to reduce the severity of future wildfire events. During planned burn operations, firefighters can work long shifts. Furthermore, remote burning locations may require firefighters to sleep away from home between shifts. The existing evidence surrounding firefighters’ sleep during such operations is exclusively anecdotal. The aims of the study were to describe firefighters’ sleep during planned burn operations and evaluate the impact of the key operational factors (shift start time, shift length and sleeping location) that may contribute to inadequate sleep. Thirty-three salaried firefighters were recruited from Australia’s fire agencies and sleep was measured objectively using wrist actigraphy for four weeks. All variables were examined in two conditions: (1) burn days, and (2) non-burn days. Time in bed, total sleep time, sleep latency and sleep efficiency were evaluated objectively. Subjective reports of pre- and post-sleep fatigue, sleep location, sleep quality, sleep quantity, number of times woken and sleep timing were also recorded. Analyses revealed no differences in measures of sleep quantity and quality when comparing non-burn and burn days. Total sleep time was less when planned burn shifts were >12 h. However, on burn days, work shift start time as well as sleeping location did not impact firefighters’ sleep quantity. Self-reported levels of pre- and post-sleep fatigue were greater on burn days compared to non-burn days. These findings indicate that sleep quantity and quality are not compromised during planned burn operations <12 h in duration. 相似文献
993.
994.
Fast‐scan cyclic voltammetry demonstrates that L‐DOPA produces dose‐dependent,regionally selective bimodal effects on striatal dopamine kinetics in vivo
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995.
996.
Disentangling vegetation diversity from climate–energy and habitat heterogeneity for explaining animal geographic patterns
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Borja Jiménez‐Alfaro Milan Chytrý Ladislav Mucina James B. Grace Marcel Rejmánek 《Ecology and evolution》2016,6(5):1515-1526
Broad‐scale animal diversity patterns have been traditionally explained by hypotheses focused on climate–energy and habitat heterogeneity, without considering the direct influence of vegetation structure and composition. However, integrating these factors when considering plant–animal correlates still poses a major challenge because plant communities are controlled by abiotic factors that may, at the same time, influence animal distributions. By testing whether the number and variation of plant community types in Europe explain country‐level diversity in six animal groups, we propose a conceptual framework in which vegetation diversity represents a bridge between abiotic factors and animal diversity. We show that vegetation diversity explains variation in animal richness not accounted for by altitudinal range or potential evapotranspiration, being the best predictor for butterflies, beetles, and amphibians. Moreover, the dissimilarity of plant community types explains the highest proportion of variation in animal assemblages across the studied regions, an effect that outperforms the effect of climate and their shared contribution with pure spatial variation. Our results at the country level suggest that vegetation diversity, as estimated from broad‐scale classifications of plant communities, may contribute to our understanding of animal richness and may be disentangled, at least to a degree, from climate–energy and abiotic habitat heterogeneity. 相似文献
997.
With increasing urbanization, urban‐fragmented landscapes are becoming more and more prevalent worldwide. Such fragmentation may lead to small, isolated populations that face great threats from genetic factors that affect even avian species with high dispersal propensities. Yet few studies have investigated the population genetics of species living within urban‐fragmented landscapes in the Old World tropics, in spite of the high levels of deforestation and fragmentation within this region. We investigated the evolutionary history and population genetics of the olive‐winged bulbul (Pycnonotus plumosus) in Singapore, a highly urbanized island which retains <5% of its original forest cover in fragments. Combining our own collected and sequenced samples with those from the literature, we conducted phylogenetic and population genetic analyses. We revealed high genetic diversity, evidence for population expansion, and potential presence of pronounced gene flow across the population in Singapore. This suggests increased chances of long‐term persistence for the olive‐winged bulbul and the ecosystem services it provides within this landscape. 相似文献
998.
Rainer W. Bussmann Narel Y. Paniagua-Zambrana Nick Wood Sankairi Ole Njapit James Nkiingis Ole Njapit Grace Sorimpan Ene Osoi Simon Pariken Kasoe 《Economic botany》2018,72(2):207-216
Traditional plant use is of tremendous importance in many societies, including most rural African communities. A variety of studies have shown knowledge dwindling due to changes towards a more Western lifestyle, and the influence of modern tourism. In the case of the Sekenani Maasai, we hypothesized in 2006 that, while little knowledge loss had been observed at that time, the change from a nomadic to a more sedentary lifestyle would lead to an accelerating loss of traditional plant knowledge. This paper examines the plant use of the Maasai in the Sekenani Valley, North of the Maasai Mara National Reserve 15 years after a first study. Based on the study of 2002 (Bussmann et al. Journal of Ethnobiology and Ethnomedicine 2: 22, 2006), semi-structured interviews were conducted with staff of Sekenani Camp in order to document current plant knowledge. The results of this follow-up study indicate dramatic knowledge loss over the last 15 years. Of 139 used species documented in 2002, only 84 remained in use in 2017. Off those species still in use, 30 had experienced a loss of uses, while for 18 species new uses were documented. The knowledge loss observed in Sekenani in 15 years is rather dramatic. Lifestyle changes and over-use of resources have clearly led to a rapid decline of traditional knowledge on plant use. This trend is expected to continue. 相似文献
999.
Milk is an important source of energy and nutrients, especially for children, and in Kenya, milk consumption is higher than other countries in the region. One major concern with milk is the risks of chemical contaminants, and reports of high levels of aflatoxin M1 (AFM1) in milk in Kenya has been causing public health concerns. This study collected marketed milk products every month during 1 year, just as a consumer would purchase them from retailers and traders in a low-income area, and a major supermarket in a middle/high-income area. In total, 291 sampled milk products (raw, pasteurised, UHT milk, yoghurt and lala) were collected and analysed for AFM1 using a commercial ELISA kit. More than 50% of the samples exceeded 50 ng/kg (the level allowed in the EU), but only three samples exceeded 500 ng/kg (the level allowed in the USA). Geometric mean AFM1 level was 61.9 ng/kg in the 135 samples from the low-income area while it was 36.1 ng/kg in the 156 from the higher income area (p?<?0.001). The levels varied significantly depending on the time of year, with lowest levels of milk in January. There were also differences between manufacturers and products, with UHT milk having lower levels. There was no difference depending on the price for all dairy products, but when only including milk, higher price was associated with lower levels of AFM1. In conclusion, this study shows that milk purchased by a consumer is likely to contain AFM1 above 50 ng/kg, and that further research is needed to find ways to mitigate AFM1 contamination through working with farmers and milk processors both in the formal and informal sectors. 相似文献