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411.
This paper establishes that an isotropic spatial correlation function in the form of a modified Bessel function of the second kind, first order, can be used to model the spatial variability of a pollution concentration field over a sufficiently long period of time in which the variability due to meteorological factors has been smoothed out. The corresponding cumulative semivariogram is derived and fitted by nonlinear least-squares to monthly averaged ozone data at 18 monitoring stations of the Sydney region. The good fit of the model indicates that the Sydney airshed has homogeneous and isotropic subregions whose radius of influence is about 17 km. The Bessel function form of the spatial correlation has a physical meaning as it is derived from the diffusion equation; hence, it is expected that the model can be used, in general, to represent the spatial variability of a smoothed homogeneous and isotropic concentration field. 相似文献
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We examined the relationship between maternal care and ant-tending in the treehopper species, Publilia modesta. Ant-tending increased the number of nymphs surviving to adulthood by approximately fivefold. Maternal care increased the number of nymphs surviving to adulthood by approximately 50% in the presence of ants. Maternal care had either no effect or the opposite effect in the absence of ants; when ants were not present survivorship was 30% lower in the presence of mothers. Maternal care increased the average number of ants tending nymph aggregations approximately threefold early in the summer; consequently, we suggest that the primary benefit of maternal care is to attract ants while nymphs are small and few in number. Because there was no benefit of maternal care in the absence of ants, we conclude that ant-tending provides an ecological context that favors maternal care in this treehopper species. 相似文献
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Examining relationships between climate change and mental health in the Circumpolar North 总被引:1,自引:0,他引:1
417.
Constance M. O’Connor Adam R. Reddon Susan E. Marsh-Rollo Jennifer K. Hellmann Isaac Y. Ligocki Ian M. Hamilton Sigal Balshine 《Die Naturwissenschaften》2014,101(10):839-849
Social interactions facilitate pathogen transmission and increase virulence. Therefore, species that live in social groups are predicted to suffer a higher pathogen burden, to invest more heavily in immune defence against pathogens, or both. However, there are few empirical tests of whether social species indeed invest more heavily in immune defence than non-social species. In the current study, we conducted a phylogenetically controlled comparison of innate immune response in Lamprologine cichlid fishes. We focused on three species of highly social cichlids that live in permanent groups and exhibit cooperative breeding (Julidochromis ornatus, Neolamprologus pulcher and Neolamprologus savoryi) and three species of non-social cichlids that exhibit neither grouping nor cooperative behaviour (Telmatochromis temporalis, Neolamprologus tetracanthus and Neolamprologus modestus). We quantified the innate immune response by injecting wild fishes with phytohaemagglutinin (PHA), a lectin that causes a cell-mediated immune response. We predicted that the three highly social species would show a greater immune reaction to the PHA treatment, indicating higher investment in immune defence against parasites relative to the three non-social species. We found significant species-level variation in immune response, but contrary to our prediction, this variation did not correspond to social system. However, we found that immune response was correlated with territory size across the six species. Our results indicate that the common assumption of a positive relationship between social system and investment in immune function may be overly simplistic. We suggest that factors such as rates of both in-group and out-group social interactions are likely to be important mediators of the relationship between sociality and immune function. 相似文献
418.
Improved Weather Generator Algorithm for Multisite Simulation of Precipitation and Temperature
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Leanna M. King A. Ian McLeod Slobodan P. Simonovic 《Journal of the American Water Resources Association》2015,51(5):1305-1320
The KnnCAD Version 4 weather generator algorithm for nonparametric, multisite simulations of temperature and precipitation data is presented. The K‐nearest neighbor weather generator essentially reshuffles the historical data, with replacement. In KnnCAD Version 4, a block resampling scheme is introduced to preserve the temporal correlation structure in temperature data. Perturbation of the reshuffled variable data is also added to enhance the generation of extreme values. The Upper Thames River Basin in Ontario, Canada is used as a case study and the model is shown to simulate effectively the historical characteristics at the site. The KnnCAD Version 4 approach is shown to improve on the previous versions of the model and offers a major advantage over many parametric and semiparametric weather generators in that multisite use can be easily achieved without making statistical assumptions dealing with the spatial correlations and probability distributions of each variable. 相似文献
419.
Davidson Kirklyn B. Holmes Baillie E. J. Spooner Ian S. Dunnington Dewey W. Walker Tony R. Lake Craig B. Su Chih-Chieh 《Environmental science and pollution research international》2021,28(37):51342-51355
Environmental Science and Pollution Research - The paleolimnological method was used to decouple geogenic and anthropogenic metal (loids) contributions in a sediment stabilization basin (Boat... 相似文献
420.
Montano Luigi Donato Francesco Bianco Pietro Massimiliano Lettieri Gennaro Guglielmino Antonino Motta Oriana Bonapace Ian Marc Piscopo Marina 《Environmental science and pollution research international》2021,28(28):37031-37040
Environmental Science and Pollution Research - The epidemic of the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has impacted worldwide with its infectious spread and mortality... 相似文献