Prenatal diagnosis for the detection of down syndrome: Why are so few eligible women tested?

Postpartum women ≧ 33 years were interviewed about their attitudes to and knowledge and use of prenatal diagnosis. Overall, 68 per cent had heard of prenatal diagnosis; nevertheless, only 30 per cent of those ≧ 35 had actually been tested. The only significant difference between eligible women who were tested and those who were not was maternal age. Of those tested, half requested it for themselves; conversely, only two-thirds of women requesting the procedure actually received it. Among women not tested, 82 per cent were never offered the procedure by the physician. Expressed attitudes to prenatal diagnosis were strongly positive among all women, with 75 per cent continuing to want testing after learning both their age-specific risk of having an affected child and the possible risks of amniocentesis. The data document a potential demand for amniocentesis far in excess of current use and present service facilities. They suggest, moreover, that underuse may reflect professional hesitation and underreferral more than consumer lack of demand or reluctance to be tested.     

Assessment of heavy metal pollution from a Fe-smelting plant in urban river sediments using environmental magnetic and geochemical methods

Environmental magnetic proxies provide a rapid means of assessing the degree of industrial heavy metal pollution in soils and sediments. To test the efficiency of magnetic methods for detecting contaminates from a Fe-smelting plant in Loudi City, Hunan Province (China) we investigated river sediments from Lianshui River. Both magnetic and non-magnetic (microscopic, chemical and statistical) methods were used to characterize these sediments. Anthropogenic heavy metals coexist with coarse-grained magnetic spherules. It can be demonstrated that the Pollution Load Index of industrial heavy metals (Fe, V, Cr, Mo, Zn, Pb, Cd, Cu) and the logarithm of saturation isothermal remanent magnetization, a proxy for magnetic concentration, are significantly correlated. The distribution heavy metal pollution in the Lianshui River is controlled by surface water transport and deposition. Our findings demonstrate that magnetic methods have a useful and practical application for detecting and mapping pollution in and around modern industrial cities.     

日益提高的中小企业环境性能与环保产品宣言指标

在关于改善环境的科学与政策讨论中,最经常提到的话题之一就是如何使小型和中等规模的企业参与进来.     

Genetic monogamy in the common loon (Gavia immer)

We conducted behavioral observations and genetic analysis on breeding pairs of common loons in the upper Great Lakes region from 1993 through 1995 to look for behavioral evidence of extrapair copulations (EPCs) and to determine parentage of young. Pairs remained close to each other (usually within 20 m) during the pre-laying period, leaving little opportunity for EPCs to occur. Males and females both maintained physical proximity by approaching each other when they became separated. Copulations were obvious but infrequent, occurring about once every other day during the pre-laying period. Multilocus DNA fingerprinting was consistent with behavioral findings: 58 young from 47 different families were all genetic offspring of parents that raised them. Perfect genetic monogamy (genetic parentage of young by parents that rear them) in loons might arise as a consequence of the need for vigorous territorial defense to prevent territorial takeover. Received: 8 August 1996 / Accepted after revision: 22 March 1997     

Making habitat selection more “familiar”: a review

Behavioral ecologists generally agree that animals derive benefits from familiarity with spaces that they inhabit or visit, yet site familiarity is rudimentary or lacking in most models of habitat selection. In this review, I examine evidence for the occurrence of site familiarity and its fitness benefits, describe the difficulty of measuring site familiarity, note its omission from the influential ideal free and ideal despotic models, and use a literature search to test an assumption of the ideal models that has become widespread in habitat selection theory: that animals behave without regard for site familiarity. I find little support for such “familiarity blindness” in vertebrates. Next I discuss how the study of public information has drawn attention away from site familiarity and point out that both kinds of information are likely to be important in habitat selection. I proceed to examine current models of initial settlement (exploration and settlement of prebreeders on first territories) and optional resettlement (site fidelity or dispersal by established breeders following a period of prospecting) and find that the latter include only basic forms of site familiarity. Hence, I develop the concept that an inhabited space holds a unique “private value” to an animal based on its familiarity with the space and offer a simple model for optional resettlement based on private value that generates several novel predictions, including site fidelity based on cumulative breeding site familiarity and high site fidelity among species with complex territories.     

Evaluating the accuracy of the benefit transfer method: a rural water supply application in the USA.

Due to declining federal, state, and local government budgets, there is an increasing need to analyze the benefits of government funded programs to determine where increasingly limited funds would best be spent. The benefits transfer technique is analyzed for the development of a rural water supply system and guidelines for successful benefits transfer are presented. Benefit transfer appears to provide reasonably accurate estimates of natural resource benefits if a broad based benefit model is used. The benefits-transfer-based estimates are accurate as long as a model based on data from a wide variety of conditions is used or the model is based on data from a very similar region. The wide-based data modeling approach has the greatest practical application. These findings are based upon contingent valuation data obtained from four sites in the western USA.     

Patch Occupancy and Potential Metapopulation Dynamics of Three Forest Mammals in Fragmented Afromontane Forest in South Africa

Abstract: We investigated the persistence of three medium-sized (2–9 kg), rare forest mammals in the fragmented mist-belt Podocarpus forests of the midlands of KwaZulu-Natal Province, South Africa. We recorded patch occupancy of blue duiker (   Philantomba monticola ), tree hyrax (   Dendrohyrax arboreus ), and samango monkey ( Cercopithecus mitis labiatus ) in 199 forest patches. Their rarity is ascribed to the fragmentation and destruction of their forest habitat. Incidence functions, derived from presence and absence data, were formulated as generalized linear models, and environmental effects were included in the fitted logistic models. The small and mostly solitary hyrax and duiker persisted in smaller patches than the large and social monkey. Although this result follows expectations based on relative home-range sizes of each species, the incidence probability of the samango monkey was invariant with increasing isolation, whereas a gradual decrease with increasing isolation was observed for the hyrax and duiker. Group dynamics may inhibit dispersal and increase the isolation effect in social species such as samango monkeys. A mainland-island metapopulation model adequately describes patterns of patch occupancy by the hyrax and duiker, but the monkeys' poor dispersal ability and obvious area-dependent extirpation suggest that they exist in transient, nonequilibrium (declining) metapopulations. Through identification of large forest patches for careful protection and management, the survival of all three species—especially the monkey—could be prolonged. Because no functional metapopulation may exist for the monkey, however, this is an emergency measure. For the duiker and hyrax, larger patches should form part of a network of smaller and closer patches in a natural matrix.