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1.
Spatial variation in soil inorganic nitrogen across an arid urban ecosystem   总被引:4,自引:1,他引:3  
We explored variations in inorganic soil nitrogen (N) concentrations across metropolitan Phoenix, Arizona, and the surrounding desert using a probability-based synoptic survey. Data were examined using spatial statistics on the entire region, as well as for the desert and urban sites separately. Concentrations of both NO3-N and NH4-N were markedly higher and more heterogeneous amongst urban compared to desert soils. Regional variation in soil NO3-N concentration was best explained by latitude, land use history, population density, along with percent cover of impervious surfaces and lawn, whereas soil NH4-N concentrations were related to only latitude and population density. Within the urban area, patterns in both soil NO3-N and NH4-N were best predicted by elevation, population density and type of irrigation in the surrounding neighborhood. Spatial autocorrelation of soil NO3-N concentrations explained 49% of variation among desert sites but was absent between urban sites. We suggest that inorganic soil N concentrations are controlled by a number of ‘local’ or ‘neighborhood’ human-related drivers in the city, rather than factors related to an urban-rural gradient.  相似文献   
2.
Summary.  When evaluating potential interventions for cancer prevention, it is necessary to compare benefits and harms. With new study designs, new statistical approaches may be needed to facilitate this comparison. A case in point arose in a proposed genetic substudy of a randomized trial of tamoxifen versus placebo in asymptomatic women who were at high risk for breast cancer. Although the randomized trial showed that tamoxifen substantially reduced the risk of breast cancer, the harms from tamoxifen were serious and some were life threaten-ing. In hopes of finding a subset of women with inherited risk genes who derive greater bene-fits from tamoxifen, we proposed a nested case–control study to test some trial subjects for various genes and new statistical methods to extrapolate benefits and harms to the general population. An important design question is whether or not the study should target common low penetrance genes. Our calculations show that useful results are only likely with rare high penetrance genes.  相似文献   
3.
Minorities and females are underrepresented in the top-income quintile of law school graduates. Employing a binary logistic regression model, I examine whether this is due to a“glass ceiling” (an invisible barrier erected by third parties) or a“sticky floor” (self-imposed limitations regarding employment). My major finding is that being female, a minority, or disabled did not significantly reduce one's probability of making the top-income quintile once hours of work, experience, and other factors are taken into account. My findings directly contradict the large body of glass-ceiling literature and support the sticky-floor model. I thank the Law School Admission Council for funding this research. Helpful comments and suggestions were received from Robert Nelson of Northwestern University and the American Bar Foundation, Steven Conroy of the University of West Florida, and R. Kim Craft and Douglas Bonzo of Southern Utah University. The views expressed here are solely those of the author and do not necessarily reflect those of the institutions or persons listed above.  相似文献   
4.
Conclusion Each theory and, ultimately, school of theorizing exposes and criticizes the theorizing of others, and at the same time contains false or misleading statements. Theory as it is must rest on some presuppositions. Thus, Marxism exposes the flaws and lies of capitalism while positing another world view-Marxism—which it does not treat critically. Marxism also provides a critique of positivistic thinking. In The Grundrisse, Marx engages in a dialogue with economists and philosophers of his day. His theory emerges out of the rejection of their theory. Ethnomethodology can be seen as critique of positivism, too. It can also tell us something about Marxism, as some of its concerns are similar, although the methods are dissimilar. At the same time, ethnomethodology denies us certain information about itself. Theorists, then, question others and not themselves. Theory can be seen as a product of inquiry; the theorist shows only the product and hides what made the product. Indeed, just as the statistician reveals a correlation between two variables and omits all the common sense reasoning that went into the process (a method of theorizing ethnomethodologists criticize), so does the ethnomethodologist or Marxist omit, to a great extent, the process of theorizing involved.Thus, while neither form of theorizing, taken literally, can be critical (for to be critical, one must sometimes suspend belief in one's own theory, bracket it, or see it as strange), either form, if taken metaphorically (and in a way that is unfaithful to Marxism and ethnomethodology), can be used for critique.The ethnomethodological and Marxist critiques of social information, as in their processual framework and their emphasis on the thinking individual, provide critiques of contemporary society and an impetus to try to change it. Links between the two schools of theorizing would perhaps help overcome the deficiencies of each mode of theorizing. Taylor, Walton, and Young advocated (although they never carried it out) building a bridge in criminology so to speak, between ethnomethodology and Marxism. The advantage would be to enable us to escape from the straitjacket of an economic determinism and the relativism of some subjective approaches to a theory of contradiction in a social structure which recognizes in deviance the acts of men (men and women) in the process of actively making, rather than passively taking, the external world.Our special thanks to Ishna Abrams, Igor Freund, and Peter Schwarzburg for their tireless assistance.  相似文献   
5.
We describe a model to obtain strengths and rankings of players appearing in golf's Ryder Cup. Obtaining rankings is complicated because of two reasons. First, competitors do not compete on an equal number of occasions, with some competitors appearing too infrequently for their ranking to be estimated with any degree of certainty, and second, different competitors experience different levels of volatility in results. Our approach is to assume the competitor strengths are drawn from some common distribution. For small numbers of competitors, as is the case here, we fit the model using Monte-Carlo integration. Results suggest there is very little difference between the top performing players, though Scotland's Colin Montgomerie is estimated as the strongest Ryder Cup player.  相似文献   
6.
This article focuses on policy advocacy programmes in Nepal and Nigeria, instigated by ActionAid International with local women's rights organisations and non-government organisations, and supported by the Institute of Development Studies, UK. These programmes aimed to challenge women's unequal responsibility for care work and to influence policymakers to understand the importance of providing services to support them. One of the main components of these programmes was child care, a responsibility which most women experience 24/7 for at least two decades of their lives, and which profoundly shapes their lives and opportunities. We examine the processes through which each of the country teams have engaged with public policies on this issue, focusing on the similarities and differences in each context. Although the programme of activities has been implemented in much the same way in both countries, and each chose to focus on early child-care provision as the main policy demand, the partnerships and policy processes chosen differ greatly. Specifically, we distinguish between ‘critical engagement’ (in the case of Nepal), as compared to ‘constructive engagement’ (in the case of Nigeria). The article ends with some reflections on the challenges facing the teams during their work, and the implications and lessons that can be drawn from these two case studies.  相似文献   
7.
Specific efforts by hospital accreditation organizations encourage renovation of nursing stations, so nurses can better see, attend, and care for their patients. The purpose of this study was to examine the effect of nursing station design on the therapeutic milieu in an adult acute care psychiatric unit. A repeated cross-sectional, pretest-posttest design was used. Data were collected from a convenience sample of 81 patients and 25 nursing staff members who completed the Ward Atmosphere Scale. Pretest data were collected when the unit had an enclosed nursing station, and posttest data were collected after renovations to the unit created an open nursing station. No statistically significant differences were found in patient or staff perceptions of the therapeutic milieu. No increase in aggression toward staff was found, given patients' ease of access to the nursing station. More research is needed about the impact of unit design in acute care psychiatric settings.  相似文献   
8.
9.
In response to water quality standard violations linked to excessive organic matter (OM) and a lack of sampling data informing the Total Maximum Daily Load (TMDL), an organic matter budget was created to quantify and identify sources of OM in the lower Jordan River (Salt Lake City, UT). By sampling dissolved, fine and coarse particulate OM, as well as measuring ecosystem metabolism at seven different sites, the researchers aimed to identify the origin of excess OM, and understand pathways by which different size classes of the OM pool are generated. The dissolved fraction (DOM; 94 %) was found to be the dominant form of OM transported within the river with fine particulate organic matter (FPOM; 6 %) the second most abundant, and coarse particulate organic matter (CPOM; 1 %) transport relatively insignificant in the overall OM budget. Primary production exceeded respiratory losses in the upper river, and this, along with OM inputs from two tributaries (where water reclamation facilities discharge into the river) delivered excess OM to the impaired lower reaches. Increasing stream metabolism index (SMI) with distance downstream (>1 in the lower river) further demonstrated that transport of excessive organic matter into the lower river was from upstream sources and not due to lateral inputs. This simple approach to characterizing the organic matter budget as it relates to water quality in the Jordan River was effective and could serve as a model for future studies attempting to quantify and identify sources of OM in urban ecosystems.  相似文献   
10.
Non-hormonal approaches to premenstrual syndrome (PMS) treatment such as selective serotonin reuptake inhibitors are by no means effective for all women and frequently we must resort to endocrine therapy. During many of the hormonal approaches, PMS-like symptoms can be introduced or re-introduced during the necessary cyclical or continuous progestogen component of the therapy. This is seen with combined oral contraception, progestogen only contraception, progestogen therapy for heavy menstrual bleeding and endometriosis, sequential hormone replacement therapy and any therapeutic strategy for premenstrual syndrome where it is necessary to provide endometrial protection, including estrogen suppression of ovulation or add-back during gonadotrophin releasing hormone suppression. The link to progestogen is very often missed by health professionals. When the pattern of symptoms mimics the cyclicity of PMS, it is termed progestogen-induced premenstrual disorder. The need to use progestogen to protect the endometrium from the proliferative actions of estrogen can pose insurmountable difficulties in managing premenstrual disorders. In the absence of any really useful evidence, nearly all practice in this area depends on clinician experience. We cannot afford to wait for adequate research evidence to be produced - it never will - and so we must rely on empirical findings, clinical experience, theoretical strategies and common sense.  相似文献   
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