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The work was focused on the investigation of possible dependencies between the development of viral infection in plants and the presence of high heavy metal concentrations in soil. Field experiments have been conducted in order to study the development of systemic tobacco mosaic virus (TMV) infection in Lycopersicon esculentum L. cv. Miliana plants under effect of separate salts of heavy metals Cu, Zn and Pb deposited in soil. As it is shown, simultaneous effect of viral infection and heavy metals in tenfold maximum permissible concentration leads to decrease of total chlorophyll content in experiment plants mainly due to the degradation of chlorophyll a. The reduction of chlorophyll concentration under the combined influence of both stress factors was more serious comparing to the separate effect of every single factor. Plants' treatment with toxic concentrations of lead and zinc leaded to slight delay in the development of systemic TMV infection together with more than twofold increase of virus content in plants that may be an evidence of synergism between these heavy metal's and virus' effects. Contrary, copper although decreased total chlorophyll content but showed protective properties and significantly reduced amount of virus in plants.  相似文献   
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Extramedullary hematopoiesis (EMH) is defined as the presence of hematopoietic stem cells such as erythroid and myeloid lineage plus megakaryocytes in extramedullary sites like liver, spleen and lymph nodes and is usually associated with either bone marrow or hematological disorders. Mammary EMH is a rare condition either in human and veterinary medicine and can be associated with benign mixed mammary tumors, similarly to that described in this case.  相似文献   
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The Mentawai and Batu Island groups off the west coast of Sumatra have a complicated geological and biogeographical history. The Batu Islands have shared a connection with the Sumatran ‘mainland’ during periods of lowered sea level, whereas the Mentawai Islands, despite being a similar distance from Sumatra, have remained isolated from Sumatra, and probably from the Batu Islands as well. These contrasting historical relationships to Sumatra have influenced the compositions of the respective mammalian faunas of these island groups. Treeshrews (Scandentia, Tupaiidae) from these islands have, at various times in their history, been recognized as geographically circumscribed populations of a broadly distributed Tupaia glis, subspecies, or distinct species. We used multivariate analyses of measurements from the skull and hands to compare the island populations from Siberut (Mentawai Islands) and Tanahbala (Batu Islands) with the geographically adjacent species from the southern Mentawai Islands (T. chrysogaster) and Sumatra (T. ferruginea). Results from both the skull and manus of the Siberut population show that it is most similar to T. chrysogaster, whereas the Tanahbala population is more similar to T. ferruginea, confirming predictions based on island history. These results are further corroborated by mammae counts. Based on these lines of evidence, we include the Siberut population in T. chrysogaster and the Tanahbala population in T. ferruginea. Our conclusions expand the known distributions of both the Mentawai and Sumatran species. The larger geographical range of the endangered T. chrysogaster has conservation implications for this Mentawai endemic, so populations and habitat should be re‐evaluated on each of the islands it inhabits. However, until such a re‐evaluation is conducted, we recommend that the IUCN Red List status of this species be changed from ‘Endangered’ to ‘Data Deficient’. Published 2013. This article is a U.S. Government work and is in the public domain in the USA, Biological Journal of the Linnean Society, 2014, 111 , 290–304.  相似文献   
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Pika species generally fall into two ecotypes, meadow‐dwelling (burrowing) or talus‐dwelling, a classification that distinguishes a suite of different ecological, behavioral, and life history traits. Despite these differences, little morphological variation has previously been documented to distinguish among ecotypes. The aim of this study was to test whether postcranial features related to burrowing are present in meadow‐dwelling species and whether talus‐dwelling species exhibit postcranial modifications related to frequent leaping between rocks. To test this, the scapula, humerus, ulna, radius, innominate, femur, tibia, and calcaneus of 15 species were studied and measured. Twenty‐three measurements were taken on 199 skeletons, and 19 indices were constructed from these measurements. Indices were compared between the two ecotypes using Student's t‐test. Comparisons among ecotypes, species, and subgenera were made using one‐way ANOVA with the Tukey honest significant difference post hoc test. Multivariate results were generated using principal components analyses. Thirteen forelimb and hind limb indices proved significant in distinguishing the meadow‐dwelling, talus‐dwelling, and intermediate forms. A number of these indices are associated with burrowing or leaping in other mammals, providing some support for the hypothesis that postcranial modifications in pika are related to locomotor differences. This evidence of morphological responses to ecological specialization will be useful for reconstructing the paleobiology of extinct taxa, assessing the behavioral variability of extant species, and improving our understanding of the evolutionary history of pikas. J. Morphol., 2013. © 2013 Wiley Periodicals, Inc.  相似文献   
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The biological diversity and composition of microorganisms influences both human health outcomes and ecological processes; therefore, understanding the factors that influence microbial biodiversity is key to creating healthy, functional landscapes in which to live. In general, biological diversity is predicted to be limited by habitat size, which for green areas is often reduced in cities, and by chronic disturbance (stress). These hypotheses have not previously been tested in microbial systems in direct comparison to macroorganisms. Here we analyzed bacterial, fungal and ant communities in small road medians (average area 0.0008 km2) and larger parks (average area 0.64 km2) across Manhattan (NYC). Bacterial species richness was not significantly different between medians and parks, but community composition was significantly distinct. In contrast, ant communities differed both in composition and richness with fewer ant species in medians than parks. Fungi showed no significant variation in composition or richness but had few shared taxa between habitats or sites. The diversity and composition of microbes appears less sensitive to habitat patchiness or urban stress than those of macroorganisms. Microbes and their associated ecosystem services and functions may be more resilient to the negative effects of urbanization than has been previously appreciated.  相似文献   
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Increasing temperatures associated with climate change are predicted to cause reductions in body size, a key determinant of animal physiology and ecology. Using a four‐decade specimen series of 70 716 individuals of 52 North American migratory bird species, we demonstrate that increasing annual summer temperature over the 40‐year period predicts consistent reductions in body size across these diverse taxa. Concurrently, wing length – an index of body shape that impacts numerous aspects of avian ecology and behaviour – has consistently increased across species. Our findings suggest that warming‐induced body size reduction is a general response to climate change, and reveal a similarly consistent and unexpected shift in body shape. We hypothesise that increasing wing length represents a compensatory adaptation to maintain migration as reductions in body size have increased the metabolic cost of flight. An improved understanding of warming‐induced morphological changes is important for predicting biotic responses to global change.  相似文献   
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Disordered eating attitudes and behaviors appear to be quite common in youth, and overweight youth have been identified as a subset of the population at particularly high risk for endorsing such symptoms. Overweight and eating disorder (ED) symptomatology independently confer significant threats to one's physical and psychosocial health, showing strong links with body weight gain and risk for ED development. When concurrent, the risk for negative health outcomes may be compounded. The purpose of this article is to review the current state of the literature as it concerns disordered eating and its correlates in overweight children and adolescents. Extant literature on the prevalence, distribution, correlates, and etiology of disordered eating attitudes and behaviors (i.e., negative attitudes toward shape and weight, unhealthy weight control behaviors, and binge eating) in overweight youth is reviewed and consolidated in order to make assessment and treatment recommendations for healthcare providers. The current literature suggests that early detection of disordered eating in overweight youth should be a priority to provide appropriate intervention, thereby helping to slow the trajectory of weight gain and prevent or reduce the long-term negative consequences associated with both conditions. Future research should focus on explicating developmental pathways, and on developing novel prevention and treatment interventions for overweight youth exhibiting disordered eating patterns.  相似文献   
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