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OALib Journal期刊
ISSN: 2333-9721
费用:99美元
投稿
时间不限
( 2673 )
( 2672 )
( 2024 )
( 2023 )
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The Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) methodology was applied to detect changes in perennial vegetation cover at marshland sites in Northern California reported to have undergone restoration between 1999 and 2009. Results showed extensive contiguous areas of restored marshland plant cover at 10 of the 14 sites selected. Gains in either woody shrub cover and/or from a recovery of herbaceous cover that remains productive and evergreen on a year round basis could be mapped out from the image results. However, LEDAPS may not be highly sensitive changes in wetlands that have been restored mainly with seasonal herbaceous cover (e.g., vernal pools), due to the ephemeral nature of the plant greenness signal. Based on this evaluation, the LEDAPS methodology would be capable of fulfilling a pressing need for consistent, continual, low-cost monitoring of changes in marshland ecosystems of the Pacific Flyway.
This paper considers efficient set mathematics for the case where the covariance matrix of asset returns is assumed known but ex ante the vector of expected returns is replaced by an estimated or forecast value. It is shown that the ex post mean and variance differ from the standard results. Consequently the maximum Sharpe ratio portfolio also differs from the standard result. However, even with uncertainty about the vector of expected returns, subject to the assumptions made about the joint distribution of actual returns and estimated mean returns, ex post Sharpe ratio maximisers hold the ex post market portfolio. The properties of the zero beta portfolio are similar to the standard results leading to a capital market line. The ex post Capital Asset Pricing Model incorporates an intercept and the betas are not the same as those computed ex ante. The results are illustrated with an example.
This broad ranging discussion examines the clinical encounter and deconstructs psychological and cultural context and implications, finally honoring the comprehensive awareness that the clinician requires for best practice in encountering mortality. Clinicians engage client disease and dying presentions, and ultimate mortality. Communicating mortality openly or subliminally is not always conscious. Mortality awareness can produce stress and untoward behaviors. Psychological mortality avoidance, citing Kierke-gaard’s existential paradox, and the death (in both senses) of Joseph Campbell’s cultural hero illumine socio-cultural elements including the elusive “good death”, sequestration of death from society, and the concept of managing death in volume. Cultural diversity awareness and the concept of transcendence clarify outlier and hybrid cultural client presentations demanding maximal clinician flexibility. Mortality Salience Theory predicts contracted world view when confronted with mortality, demanding sensitivity to a variety of responses. A hospice approach may not be best for some, despite a lack of new alternative to that paradigm. Managing mortality awareness and dying stresses the clinician by the weight and loneliness of perhaps unpopular decisions, by responsibility to community in managing death, and by the take-home exposure of the clinician’s family to the concept of death and mortality. Aptitude for managing death depends on clinician self awareness and a good match with practice venue. Clinician integrity and consciousness of motives and responses allows engagement or deferral as necessary without threat to identity.
Trends in the growing season MODerate resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) time-series were analyzed for the period from 2000 to 2010 to understand landscape-level patterns of vegetation change in ecosystems of arctic Alaska. We compared datasets for vegetation cover types, wetland cover classes, wildfire boundaries since the 1940s, permafrost type, and elevation to identify the most likely combination of factors driving regional changes in habitat quality and ecosystem productivity. Approximately 57% of all arctic ecosystem areas in Alaska were detected with significant (p < 0.05) positive or negative MODIS growing season EVI trends from 2000 to 2010. Nearly all (99%) of these ecosystem areas (covering 178,050 km2) were detected with significant positive growing season EVI trends. The vast majority of the arctic Alaska region detected with significant positive growing season EVI trends was classified as upland tundra cover, although non-forested wetlands (marshes, bogs, fens, and floodplains) were co-located on 8% of that area. Herbaceous wetlands were co-located on 55% of the total area detected with significant negative growing season EVI trends, mostly on the arctic coastal plain and foothills. This evidence supports the hypothesis that temperature (warming) has markedly enhanced the rates of upland tundra vegetation growth across most of arctic Alaska over recent years.