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1.
Time and Complexity in Historical Ecology: Studies in the Neotropical Lowlands . William Baleé and Clark L. Erickson, eds. New York: Columbia University Press, 2006. 417 pp.  相似文献   
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Summary

Monthly samples of the shore crab Pachygrapsus transversus from two distinct annual periods showed that ovigerous females are present throughout the year in the population. However, the relative ovigerous abundance of specimens among sexually mature changes from less than 10% during the winter months to almost 80% in summer. Linear correlations for each year revealed that both temperature and photoperiod were positively associated with relative abundance of ovigerous females. Multiple regression analyses suggested that photoperiod was the main factor affecting breeding in this species. Timing of observed reproductive pattern may enhance larval survival because of particular oceanographic conditions in the study region and favor early juvenile development due to certain species-specific growth features.  相似文献   
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Background aims

Multipotent mesenchymal stromal cell (MSC)-based medicines are extensively investigated for use in regenerative medicine and immunotherapy applications. The International Society for Cell and Gene Therapy (ISCT) proposed a panel of cell surface molecules for MSC identification that includes human leukocyte antigen (HLA)-DR as a negative marker. However, its expression is largely unpredictable despite production under tightly controlled conditions and compliance with current Good Manufacturing Practices. Herein, we report the frequency of HLA-DR expression in 81 batches of clinical grade bone marrow (BM)-derived MSCs and investigated its impact on cell attributes and culture environment.

Methods

The levels of 15 cytokines (interleukin [IL]-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, interferon-γ, soluble CD40 ligand and tumor necrosis factor-α) were determined in sera supplements and supernatants of BM-MSC cultures. Identity, multipotentiality and immunopotency assays were performed on high (>20% of cells) and low (≤20% of cells) HLA-DR+ cultures.

Results

A correlation was found between HLA-DR expression and levels of IL-17F and IL-33. Expression of HLA-DR did neither affect MSC identity, in vitro tri-lineage differentiation potential (into osteogenic, chondrogenic and adipogenic lineages), nor their ability to inhibit the proliferation of stimulated lymphocytes.

Discussion

Out of 81 batches of BM-MSCs for autologous use analyzed, only three batches would have passed the ISCT criteria (<2%), whereas 60.5% of batches were compliant with low HLA-DR values (≤20%). Although a cause–effect relationship cannot be drawn, we have provided a better understanding of signaling events and cellular responses in expansion culture conditions relating with HLA-DR expression.  相似文献   
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A new species of Daptonema is described based upon morphological characters and 18S rRNA sequence. Daptonema matrona sp. nov. was collected in Pina Basin (north‐eastern Brazil). It differs from all other species of the genus by the presence of reduced cephalic setae and straight spicules. These features require an adaptation of the generic diagnosis. Moreover, the females are characterized by intra‐uterine development of the offspring, considered herein as their major autapomorphic feature. Molecular systematic analyses supported Daptonema matrona sp. nov. as a distinct genetic and evolutionary lineage. The data also indicate hypotheses of taxonomic synonymies amongst some related taxa from Xyalidae as well as the paraphyly of Daptonema. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 1–15.  相似文献   
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The recent expansion of Pentecostalism and independent churches in Africa has generated growing interest among social scientists. This attention parallels a renewed interest among Africanists on witchcraft and occult activities, also believed by many to be increasing. Some suggest the two trends may be related, but it remains unclear how and why. Drawing on a study of Pentecostalism and health in the city of Chimoio, Mozambique, in 2002–03 that focused on attitudes toward recent social change, we argue that structural adjustment economic reforms have deepened economic inequality and exacerbated household stresses that affect men and women differently. Women increasingly seek spiritual help for reproductive health problems from Pentecostal churches, whereas men disproportionately pay traditional healers to engage "occult" practices to manage misfortune related to employment. The increased resort to both spiritual resources reveals social distress caused by economic adjustment, with important implications for health programs.  相似文献   
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Upland tropical forests have expanded and contracted in response to past climates, but it is not clear whether similar dynamics were exhibited by gallery (riparian) forests within savanna biomes. Because such forests generally have access to ample water, their extent may be buffered against changing climates. We tested the long‐term stability of gallery forest boundaries by characterizing the border between gallery forests and savannas and tracing the presence of gallery forest through isotopic analysis of organic carbon in the soil profile. We measured leaf area index, grass vs. shrub or tree coverage, the organic carbon, phosphorus, nitrogen and calcium concentrations in soils and the carbon isotope ratios of soil organic matter in two transitions spanning gallery forests and savanna in a Cerrado ecosystem. Gallery forests without grasses typically show a greater leaf area index in contrast to savannas, which show dense grass coverage. Soils of gallery forests have significantly greater concentrations of organic carbon, phosphorus, nitrogen and calcium than those of savannas. Soil organic carbon of savannas is significantly more enriched in 13C compared with that of gallery forests. This difference in enrichment is in part caused by the presence of C4 grasses in savanna ecosystem and its absence in gallery forests. Using the 13C abundance as a signature for savanna and gallery forest ecosystems in 1 m soil cores, we show that the borders of gallery forests have expanded into the savanna and that this process initiated at least 3000–4000 bp based on 14C analysis. Gallery forests, however, may be still expanding as we found more recent transitions according to 14C activity measurements. We discuss the possible mechanisms of gallery forest expansion and the means by which nutrients required for the expansion of gallery forest might accumulate.  相似文献   
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The Crab Plover Dromas ardeola is the only waterbird species known to provision offspring well after the post-reproductive migration and through overwintering. A few previous quantitative studies have reported inconclusively that juveniles begged rarely, and also indiscriminately at other juveniles. Here, we describe the feeding behaviour of adult and juvenile Crab Plovers during the first part of the wintering period. Juveniles begged frequently for food, always toward adults, and obtained 0.1 prey items/min from them. Begging birds obtained the largest prey items of those captured by the adults. When foraging alone, juveniles captured prey at the same rate as adults, but captured smaller crabs. The feeding success of adults was not altered by the presence of the begging juvenile. Juveniles depended partly on adults during the first part of the overwintering period, but were almost independent towards the end. Crab Plovers may adopt such unusually prolonged care because they need to abandon their breeding areas quickly, when environmental conditions are extreme. Large numbers of Crab Plovers overwinter in a few areas, now subject to human alteration. Isolated adults may forage on other areas such as narrow and disturbed shores, but juveniles may require wide beaches, suitable for group foraging, that should be considered as key areas for the recruitment of juveniles into the population.  相似文献   
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