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排序方式: 共有162条查询结果,搜索用时 15 毫秒
101.
Y.K. Eugenia Kwok Krishna Bahadur KC Jennifer J. Silver Evan Fraser 《Asia Pacific viewpoint》2020,61(1):54-70
The Tonle Sap Lake of Cambodia is one of the most productive ecosystems in the world, supporting millions of small‐scale fisher livelihoods. Women's contributions in these fisheries are often overlooked due to socio‐cultural expectations of roles and responsibilities. This is a crucial omission since climate and anthropogenic influences increasingly threaten lake inhabitants. Addressing these challenges requires the full participation of both men and women who use the lake, thus it is necessary to first understand the social dynamics of these communities. We investigated whether there were differences between men's and women's perceptions of (i) fishing and non‐fishing practices; (ii) power, access and control over fishing resources; and (iii) perceptions towards conservation and conservation areas in Pursat, Cambodia. We interviewed fishers and key informants, and found differences in perceptions of fishing and non‐fishing practices between fishermen and fisherwomen. Men more openly acknowledged unequal power dynamics, access to and control over fishing resources when compared with women. We found contrasting ideas of community fisheries and conservation between men and women, and health and safety challenges they faced in conservation areas. Findings suggest that community perspectives and unequal power relations established specific roles for women that limited their active participation in fisheries management. 相似文献
102.
Evolution of the protein repertoire 总被引:2,自引:0,他引:2
103.
104.
Terry LA Howells L Bishop K Baker CA Everest S Thorne L Maddison BC Gough KC 《Veterinary research》2011,42(1):65
ABSTRACT: Classical scrapie is a naturally transmitted prion disease of sheep and goats. Contaminated environments may contribute to the spread of disease and evidence from animal models has implicated urine, blood, saliva, placenta and faeces as possible sources of the infection. Here we sought to determine whether sheep naturally infected with classical scrapie shed prions in their faeces. We used serial protein misfolding cyclic amplification (sPMCA) along with two extraction methods to examine faeces from sheep during both the clinical and preclinical phases of the disease and showed amplification of PrPSc in 7 of 15 and 14 of 14 sheep respectively. However PrPSc was not amplified from the faeces of 25 sheep not exposed to scrapie. These data represent the first demonstration of prion shedding in faeces from a naturally infected host and thus a likely source of prion contamination in the environment. 相似文献
105.
Helioseismology is probing the interior structure and dynamics of the sun with ever-increasing precision, providing a well-calibrated laboratory in which physical processes can be studied under conditions that are unattainable on Earth. Nearly 10 million resonant modes of oscillation are observable in the solar atmosphere, and their frequencies need to be known with great accuracy in order to gauge the sun's interior. The advent of nearly continuous imaged observations from the complementary ground-based Global Oscillation Network Group (GONG) observatories and the space-based Solar and Heliospheric Observatory instruments augurs a new era of discovery. The flow of early results from GONG resolves some issues and raises a number of theoretical questions whose answers are required for understanding how a seemingly ordinary star actually operates. 相似文献
106.
MJ Thompson J Toomre ER Anderson HM Antia G Berthomieu D Burtonclay SM Chitre J Christensen-Dalsgaard T Corbard M DeRosa CR Genovese DO Gough DA Haber JW Harvey F Hill R Howe SG Korzennik AG Kosovichev JW Leibacher FP Pijpers J Provost EJ Rhodes J Schou T Sekii PB Stark PR Wilson 《Science (New York, N.Y.)》1996,272(5266):1300-1305
Splitting of the sun's global oscillation frequencies by large-scale flows can be used to investigate how rotation varies with radius and latitude within the solar interior. The nearly uninterrupted observations by the Global Oscillation Network Group (GONG) yield oscillation power spectra with high duty cycles and high signal-to-noise ratios. Frequency splittings derived from GONG observations confirm that the variation of rotation rate with latitude seen at the surface carries through much of the convection zone, at the base of which is an adjustment layer leading to latitudinally independent rotation at greater depths. A distinctive shear layer just below the surface is discernible at low to mid-latitudes. 相似文献
107.
Chris M. Hewson Graham E. AustinSu J. Gough Robert J. Fuller 《Forest Ecology and Management》2011,261(7):1224-1240
Several species of woodland birds have recently declined in Britain and there is a need to understand better how species are distributed across a wide spectrum of habitat types in order to develop appropriate conservation management strategies. To assess habitat associations of 28 woodland species, a large-scale study was carried out across Great Britain. A total of 2668 stands embedded in 825 woodland sites were surveyed. The number of species recorded in each stand and the occurrence of each species was examined in relation to the unique (or marginal) effects of gross structural characteristics of stands (growth stage and understorey structure), plant species composition (floristics) expressed in terms of dominant tree, shrub layer and field layer species and both sets of variables considered together whilst controlling for the spatial distribution of sites and site identity. The number of species recorded was independently related to growth stage, understorey structure, tree composition and field layer type. Eighteen species showed at least one significant relationship in models containing structure variables only. Thirteen species showed at least one significant relationship in models containing floristic variables only. In models containing both structure and floristic variables; 14 species showed at least one significant relationship with a structure variable, 9 species with at least one floristic variable and 8 species with both at least one structure and at least one floristic variable. Different bird species showed individualistic patterns of association with habitat variables. Results suggest that structure and floristics have complex and inter-related effects on bird distribution across woodland stands. Some of the apparent relationships with structure were a consequence of between-stand differences in floristics and vice versa whilst in two cases relationships with structure variables became apparent after controlling for the masking effects of floristic variables. Both vegetation structure and floristics appear to be important determinants of composition in bird assemblages in British woodland, though gross structural factors have previously received most emphasis. The existence of species-specific responses to habitat variation suggests that habitat heterogeneity, embracing structure and floristics, should be a key element in conservation planning within forests especially in the light of uncertainty about future regional species pools due to climate change. We discuss how responses of birds to habitat variation at the level of stands can form a basis for developing large-scale conservation strategies within managed forests. 相似文献
108.
D. R. Panthee R. B. KC H. N. Regmi P. P. Subedi S. Bhattarai J. Dhakal 《Genetic Resources and Crop Evolution》2006,53(1):205-212
A total of 179 garlic (Allium sativum L.) accessions were collected from various parts of Nepal in 2000. Each accession was planted in each of a plot of 2.25 m2 at the Institute of Agriculture and Animal Science (IAAS) Horticulture farm (225 m asl) and at the Agriculture Research Station,
Dailekh (1400 m asl) of Nepal Agriculture Research Council (NARC) in the first week of November 2000. All accessions were
characterized for leaf erectness, leaf color, leaf wax, leaf cross section, bulb regularity, bulb skin color, bulb outer scales
number, days to emergence, bulbing period, number of green leaves at 135 days after planting, days to maturity, plant height,
bulb weight, bulb diameter, number of cloves per bulb, clove diameter and bulb yield. Data were analyzed by using principal
component and cluster analysis procedures to reveal three major clusters. Four principal components were identified explaining
more than 86% of total variation. Major characters included in the principal components were bulb weight, diameter, yield,
number of cloves per bulb, maturity, plant height, number of green leaves at 135 days after planting, and bulbing period.
The level of variation found in the collection showed the great potentiality of improving agronomic characters in garlic. 相似文献
109.
Recent investigations on the Kenai Peninsula had two major objectives: (1) to establish elemental baseline concentrations ranges for native vegetation and soils; and, (2) to determine the sampling density required for preparing stable regional geochemical maps for various elements in native plants and soils. These objectives were accomplished using an unbalanced, nested analysis-of-variance (ANOVA) barbell sampling design. Hylocomium splendens (Hedw.) BSG (feather moss, whole plant), Picea glauca (Moench) Voss (white spruce, twigs and needles), and soil horizons (02 and C) were collected and analyzed for major and trace total element concentrations. Using geometric means and geometric deviations, expected baseline ranges for elements were calculated. Results of the ANOVA show that intensive soil or plant sampling is needed to reliably map the geochemistry of the area, due to large local variability. For example, producing reliable element maps of feather moss using a 50 km cell (at 95% probability) would require sampling densities of from 4 samples per cell for Al, Co, Fe, La, Li, and V, to more than 15 samples per cell for Cu, Pb, Se, and Zn. 相似文献
110.
JM MILLAN A. JANMAAT KC RICHARDSON LK CHAMBERS KR FOMIATTI 《Australian veterinary journal》1997,75(11):814-817
Objective To determine reference ranges for healthy yearling farmed saltwater crocodiles by performing routine biochemical and haematological laboratory tests on blood samples.
Design A clinico-pathological study.
Procedure Blood samples were collected from 120 healthy yearlings from four Northern Territory crocodile farms and body weight and length were measured. All animals had been fasted for 2 days before sample collection. Routine biochemical analytes were determined on 120 samples and haematological values determined on 30 samples (from one farm).
Results Reference ranges for biochemical and haemato-logical values were determined for farmed yearling saltwater crocodiles in the Northern Territory.
Conclusion The results were comparable with published reference ranges for other crocodilian species. Other published results of haematological values from saltwater crocodiles were from very young (6-week-old) hatchlings and older (2- to 4-year-old) crocodiles. Differences in values were presumed to be caused by age-related factors. 相似文献
Design A clinico-pathological study.
Procedure Blood samples were collected from 120 healthy yearlings from four Northern Territory crocodile farms and body weight and length were measured. All animals had been fasted for 2 days before sample collection. Routine biochemical analytes were determined on 120 samples and haematological values determined on 30 samples (from one farm).
Results Reference ranges for biochemical and haemato-logical values were determined for farmed yearling saltwater crocodiles in the Northern Territory.
Conclusion The results were comparable with published reference ranges for other crocodilian species. Other published results of haematological values from saltwater crocodiles were from very young (6-week-old) hatchlings and older (2- to 4-year-old) crocodiles. Differences in values were presumed to be caused by age-related factors. 相似文献