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51.
Leveraging nature's backup plans to incorporate interspecific interactions and resilience into restoration
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Clare E. Aslan Judith L. Bronstein Haldre S. Rogers Keryn B. Gedan Jedediah Brodie Todd M. Palmer Truman P. Young 《Restoration Ecology》2016,24(4):434-440
Interspecific interactions are important structuring forces in ecological communities. Interactions can be disturbed when species are lost from a community. When interactions result in fitness gains for at least one participating organism, that organism may experience reduced fitness as a result of interaction disturbance. However, many species exhibit traits that enable individuals to persist and reproduce in spite of such disruptions, resulting in resilience to interaction disturbance. Such traits can result in interaction generalization, phenotypic and behavioral plasticity, and adaptive capacity. We discuss examples of these traits and use case studies to illustrate how restoration practitioners can use a trait‐based approach to examine species of concern, identify traits that are associated with interspecific interactions and are relevant to resilience, and target such traits in restoration. Restoration activities that bolster interaction resilience could include, for example, reintroducing or supporting specific functional groups or managing abiotic conditions to reduce interaction dependence by at‐risk species (e.g. providing structural complexity offering shelter and cover). Resilience may also be an important consideration in species selection for restoration. Establishment of resilient species, able to persist after interaction disturbance, may be essential to restoring to a functioning ecological community. Once such species are present, they could help support more specialized species that lack resilience traits, such as many species of concern. Understanding the conditions under which processes linked to resilience may enable species to persist and communities to reform following interaction disturbance is a key application of community ecology to ecological restoration. 相似文献
52.
F. M. R. Walshe 《BMJ (Clinical research ed.)》1927,2(3480):516-517
53.
F. M. R. Walshe 《BMJ (Clinical research ed.)》1941,2(4223):858-859
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55.
Arthur C. Durband Judith Littleton Keryn Walshe 《American journal of physical anthropology》2014,154(4):479-485
Tooth avulsion is the intentional removal of one or more teeth for ritual or aesthetic reasons, or to denote group affiliation. Typically the maxillary incisors are the teeth most often selected for removal. Previous authors have discussed the presence of tooth avulsions in several individuals recovered from Roonka, but those papers did not examine any patterns in those removals that might be present. Analysis of the tooth avulsions at Roonka reveals a change in the practice over time, with the older burials from phase II typically showing removal of both maxillary central incisors with a left side bias when only one tooth is removed, and the more recent phase III burials showing only one incisor avulsed and a right side bias for removal. Frequencies in the practice also changed over time, with avulsions being much more common in the older phase II burials. Historical evidence suggests that any particular regional or social group would have its own particular pattern of tooth avulsion, so these changes in tooth avulsions at Roonka suggest that the site was either used by multiple groups of people for burials, or that there was significant cultural change during the occupation of the site. Am J Phys Anthropol 154:479–485, 2014. © 2014 Wiley Periodicals, Inc. 相似文献
56.
Anthropogenic climate change is predicted to cause widespread biodiversity loss due to shifts in species' distributions, but these predictions rarely incorporate ecological associations such as zonation. Here, we predict the decline of a diverse assemblage of mid-latitude salt marsh plants, based on an ecosystem warming experiment. In New England salt marshes, a guild of halophytic forbs occupies stressful, waterlogged pannes. At three sites, experimental warming of < 4 °C led to diversity declines in pannes and rapid takeover by a competitive dominant, Spartina patens . In Rhode Island, near their southern range limit, pannes were more sensitive to warming than farther north, and panne area also declined in control plots over the three-season experiment. These results suggest that warming will rapidly reduce plant diversity in New England salt marshes by eliminating a high diversity zone. Biodiversity in zoned ecosystems may be more affected by climate-driven shifts in zonation than by individual species' distribution shifts. 相似文献
57.
Foundation species structure environments and create refuge from environmental stress. In New England high salt marsh, the
grass Spartina patens is a foundation species that reduces salinity, anoxia, desiccation, and thermal stresses through canopy shading and root
proliferation. In a factorial S. patens-removal and warming field experiment, foundation species removal strongly impacted every aspect of the community, reiterating
the important role of the foundation species S. patens in the high marsh. Given this central role, we hypothesized that facilitation by the foundation species would be even more
important under warmer conditions by ameliorating more severe thermal stress. However, the ecological role of S. patens was unaffected by experimental warming, and, independent of the presence of the foundation species, warming had only weak
effects on the salt marsh ecological community. Only the foundation species itself responded strongly to warming, by significantly
increasing aboveground production in warmed plots. Apparently, amelioration of thermal stress is not as important for salt
marsh ecosystem function as S. patens’ moderation of salinity and desiccation stresses. From these experimental results, we anticipate that climate change-associated
thermal stress will not greatly affect S. patens-dominated high marsh communities. In contrast, foundation species loss, an emergent conservation issue in Atlantic salt marshes,
represents a critical threat to salt marsh ecosystem function. 相似文献
58.
Eliza Redden Uyunbilig Borjigin Keryn Hutton Geoff Hinch Jonathan Hill Muren Herrid 《Cryobiology》2009,58(2):190-195
Cryopreservation has become an integral component of any cell transplantation technique helping to overcome the issues associated with known spatial and temporal barriers between donor and recipient. The aim of this study was to develop a protocol for large quantity cryopreservation of bovine testicular germ cells. The impact of 3 different packaging methods (5 ml semen straw, 20 ml freezing bag and 1.5 ml cryovial) and varying cell densities (3 × 106, 9 × 106, or 18 × 106 cells/ml) on the survival of testis germ cells was examined. Cells processed in 5 ml semen straws had a significantly higher viability (70.7 ± 1.2%, P < 0.05) compared to those cells in 20 ml freezing bags (46.7 ± 0.1%) or 1.5 ml cryovials (46.3 ± 2.2%). For 5 ml straws, a 20 min cooling prior to cryopreservation resulted in a higher post thaw viability (73.2 ± 0.6%) than a 10 min cooling (56.0 ± 2.2%), while the density of the cell suspension did not impact on post thaw viability. Thus cryopreservation of testicular germ cells in 5 ml straws at a density between 3 × 106 and 18 × 106 cells/ml in liquid nitrogen vapour for 20 min cooling appears to be a simple and practical way to preserve cells. Subsequent testing of frozen/thawed cells exhibited viable cultures and retained the ability to proliferate. The freezing protocol does not preferentially preserve type A spermatogonia. However, the cell surface properties of somatic cells appear to be affected by the freezing procedure and therefore the frozen/thawed cells are less suitable for enriching type A spermatogonia by differential plating. 相似文献
59.
Research to date in young children and adults shows a strong, inverse relationship between sleep duration and risk for overweight and obesity. Fewer studies examining this relationship have been conducted in adolescents. The purpose of the article is to describe the relationship between sleep and weight in a population of adolescents, controlling for demographics, energy intake, energy expenditure, and depression. This is a cross-sectional study of 723 adolescents participating in population-based studies of the etiologic factors related to obesity. We examined the relationship between three weight-related dependent variables obtained through a clinical assessment and three sleep variables obtained through self-report. Average caloric intake from dietary recalls, average activity counts based on accelerometers, and depression were included as covariates and the analysis was stratified by gender and grade level. Our results show that the relationship between sleep duration and BMI is evident in middle-school boys (β = -0.32, s.e. = 0.06: P < 0.001) and girls (β = -0.18, s.e. = 0.08: P = 0.02) but largely absent in high-school students. Differences in sleep patterns have little association with weight in males, but in high-school girls, waking up late on weekends as compared to weekdays is associated with lower body fat (β = -0.80, s.e. = 0.40: P = 0.05) and a healthy weight status (β = -0.28, s.e. = 0.14: P = 0.05). This study adds to the evidence that, particularly for middle-school boys and girls, inadequate sleep is a risk factor for early adolescent obesity. Future research needs to examine the relationship longitudinally and to study potential mediators of the relationship. 相似文献
60.
Allin MP Kontis D Walshe M Wyatt J Barker GJ Kanaan RA McGuire P Rifkin L Murray RM Nosarti C 《PloS one》2011,6(10):e24525