The Lake Pontchartrain Basin in southeast Louisiana is an estuarine watershed encompassing New Orleans, Baton Rouge, and wetlands that are an integral part of Louisiana's unique culture. In recent decades rapid growth and poorly planned development have resulted in a decrease in water quality and habitat loss, especially in St. Tammany Parish on the north shore of Lake Pontchartrain. In 1989, the Lake Pontchartrain Basin Foundation (LPBF), an environmental, non-profit organization, was formed to address and rectify environmental issues in the Basin. LPBF accomplishes its mission through programs addressing water quality, habitat protection, geographic information science, public access, and education.LPBF used the recent, rapid development occurring in St. Tammany Parish as a case study to examine the relationship between land use, water quality, and development in the Basin by investigating habitat change/urbanization, development in flood plains, and water quality. Through the integration of LPBF programs, it was found that urbanization is having a devastating impact on the parish's natural habitats and severely degrading water quality. Using these results, LPBF is educating Basin citizens on the protection of their habitats and water quality to insure that these resources may be available for future generations. 相似文献
This article analyzes the evolution of a significant undercurrent within American culture challenging the dominance of the cult of youth and masculinity, through the interpretation of selected American popular films of the 1930s and 1970s/80s featuring heroines over 60 years of age. These two eras, which witnessed the impact of elder advocacy on national legislation and social policy, generated films such asIf I Had A Million (1932),Make Way for Tomorrow (1937),Harold and Maude (1971) andThe Trip to Bountiful (1985). Through analyzing these films as well as related media trends, psychoanalytic approaches to the study of female representation in cinema are critiqued. While psychoanalytic approaches often stress the cultural dominance of an ahistorical patriarchy, a sociological model conceptualizes culture as a process constituted by communication and negotiation, resistance and rebellion as well as oppression and domination.This study was funded in part by the National Endowment for the Humanities, Clark University Faculty Development Fund and the Bunting Institute, Radcliffe College. I wish to thank the staff members of the Theatre Arts Library, University of California at Los Angeles and the Division of Film, Television and Recorded Sound, Library of Congress for their help in locating films and materials. Thanks also to Lois Banner, Ruth Jacobs, Elizabeth Markson, Carmen Sirianni, the members of my Aging and Society course (Clark University, Fall, 1987) and two anonymous reviewers who offered helpful suggestions on earlier drafts of this paper. 相似文献
The exclusion restriction is usually assumed for identifying causal effects in true or only natural randomized experiments with noncompliance. It requires that the assignment to treatment does not have a direct causal effect on the outcome. Despite its importance, the restriction can often be unrealistic, especially in situations of natural experiments. It is shown that, without the exclusion restriction, the parametric model is identified if the outcome distributions of various compliance statuses are in the same parametric class and that class is a linearly independent set over the field of real numbers. However, the relaxation of the exclusion restriction yields a parametric model that is characterized by the presence of mixtures of distributions. This scenario complicates the likelihood‐based estimation procedures because it implies more than one maximum likelihood point. A two‐step estimation procedure based on detecting the root that is closest to the method of moments estimate of the parameter vector is then proposed and analyzed in detail, under normally distributed outcomes. An economic example with real data concerning returns to schooling concludes the paper. 相似文献
This article proposes a new spatial cluster detection method for longitudinal outcomes that detects neighborhoods and regions with elevated rates of disease while controlling for individual level confounders. The proposed method, CumResPerm, utilizes cumulative geographic residuals through a permutation test to detect potential clusters which are defined as sets of administrative regions, such as a town or group of administrative regions. Previous cluster detection methods are not able to incorporate individual level data including covariate adjustment, while still being able to define potential clusters using informative neighborhood or town boundaries. Often, it is of interest to detect such spatial clusters because individuals residing in a town may have similar environmental exposures or socioeconomic backgrounds due to administrative reasons, such as zoning laws. Therefore, these boundaries can be very informative and more relevant than arbitrary clusters such as the standard circle or square. Application of the CumResPerm method will be illustrated by the Home Allergens and Asthma prospective cohort study analyzing the relationship between area or neighborhood residence and repeated measured outcome, occurrence of wheeze in the last six months, while taking into account mobile locations. 相似文献
We derive estimators of the mean of a function of a quality-of-life adjusted failure time, in the presence of competing right
censoring mechanisms. Our approach allows for the possibility that some or all of the competing censoring mechanisms are associated
with the endpoint, even after adjustment for recorded prognostic factors, with the degree of residual association possibly
different for distinct censoring processes. Our methods generalize from a single to many censoring processes and from ignorable
to non-ignorable censoring processes. 相似文献
Summary We idenify the invertible coherent functional relation between an array of asserted conditional probabilities and the probability
distribution for the sum of events that are regarded exchangeably, in the regular case thatP(NN+1|SN=a) ∈ (0, 1) for everya=0, 1, ...,N. The result is used to construct a useful algebraic and geometrical representation of all coherent inferences in the regular
case, including those that are nonlinear in the sum of the conditioning events. The special case in which conditional probabilities
mimic observed frequencies within (0, 1) receives an exact solution, which allows an easy interpretation of its surprising
consequences. Finally, we introduce a new direction in research on prior opinion assessment that this approach, inverse to
the usual one, suggests. 相似文献
Background: Sarcopenia is a pathophysiological condition diffused in elderly people; it represents a social issue due to the longer life expectancy and the growing aging population. It affects negatively quality of life and it represents a risk factor for other pathologies, such as diabetes, cardiovascular disease, and obesity. No silver bullet exists to hinder sarcopenia, but it may be counteracted by physical exercise, nutrition, and a proper endocrine milieu. Indeed, we aim to analyze the scientific literature to give to clinician effective advices to counteract sarcopenia.
Main text: Physical exercise, proper nutrition, optimized hormonal homeostasis represent the three pillars to fight sarcopenia. Physical exercise represents the most effective remedy to face sarcopenia, in particular if it is combined with a proper diet and with an adequate endocrine milieu. Consistency in training, adequate daily protein intake and eugonadism seems to be the keys to fight sarcopenia. The combination of these three pillars might act synergistically.
Conclusions: Optimization of these factors may increase their efficiency; however, scientific data may be sometimes confusing so far. Therefore, we aim to give practical advices to clinician to identify and to highlight the most important aspects in each of these three factors that should be addressed. 相似文献
Search algorithms are often compared by the optimization speed achieved on some sets of cost functions. Here some properties of algorithms’ optimization speed are introduced and discussed. In particular, we show that determining whether a set of cost functions F admits a search algorithm having given optimization speed is an NP-complete problem. Further, we derive an explicit formula to calculate the best achievable optimization speed when F is closed under permutation. Finally, we show that the optimization speed achieved by some well-know optimization techniques can be much worse than the best theoretical value, at least on some sets of optimization benchmarks. 相似文献