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121.
Cleisson Fábio A. Peralta Victor Bunduki José Píndaro P. Plese Eberval Gadelha Figueiredo Javier Miguelez Marcelo Zugaib 《黑龙江环境通报》2003,23(4):311-314
This study presents 30 cases of fetal isolated spina bifida aperta (SBA) to identify prenatal ultrasound findings that could predict the prognosis. Comparisons between surviving patients who had normal (group 1) and abnormal (group 2) post-natal neurological outcomes were made for three different prenatal signs, that is, site of vertebral lesion, presence and degree of ventriculomegaly and presence of talipes. The site of the lesion was the most significant outcome predictor, as high spinal dysraphisms were observed in 2 patients (2/7–28.6%) in group 1 and in 15 patients (15/19–79.0%) in group 2 (p = 0.03). The presence of fetal ventriculomegaly was associated with impaired post-natal neurological development, as it occurred in 4 patients (4/7–57.1%) in group 1 and in 18 patients (18/19–94.7%) in group 2 (p = 0.04). The presence of talipes did not significantly differ between the two groups. Patients with abnormal intellectual outcome (8/26–30.8%) had significantly greater (p = 0.018) lateral ventricle/hemisphere ratios (mean = 0.74, standard deviation = 0.13) than those with normal intellectual development (mean = 0.54, standard deviation = 0.18). Mean post-natal follow-up was at 23 months (standard deviation = 15 months). Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
122.
Many water-related problems are shared by most of the developing countries and the industrialized nations could be in position of offering aid in such problems. Water scarcity and access to safe water, water pollution, severe storms and floods, droughts, waterborne diseases and landslides and mud floods are the most commonly shared problems among developing nations. These problems were discussed in a workshop organized as part of the Fifth International Symposium on Environmental Hydraulics in 2008. The discussion included identification of actors both in the developing and developed nations (vgr. local and national governments, NGOs, universities, foundations and private and public research institutions), aid modalities such as education, technology transfer, technology development and direct investment as well as restrictions and barriers in the form of political and legal issues, economic limitations, cultural differences and geographic distances. Recommendations about how developed nations could help developing countries are issued. 相似文献
123.
Methods to assess ecosystem services using ecological or economic approaches are considerably better defined than methods for the social approach. To identify why the social approach remains unclear, we reviewed current trends in the literature. We found two main reasons: (i) the cultural ecosystem services are usually used to represent the whole social approach, and (ii) the economic valuation based on social preferences is typically included in the social approach. Next, we proposed a framework for the social valuation of ecosystem services that provides alternatives to economics methods, enables comparison across studies, and supports decision-making in land planning and management. The framework includes the agreements emerged from the review, such as considering spatial–temporal flows, including stakeholders from all social ranges, and using two complementary methods to value ecosystem services. Finally, we provided practical recommendations learned from the application of the proposed framework in a case study.
Electronic supplementary material
The online version of this article (doi:10.1007/s13280-014-0555-2) contains supplementary material, which is available to authorized users. 相似文献124.
The clearing of forests to obtain land for pasture and agriculture and the replacement of autochthonous species by other faster-growing varieties of trees for timber have both led to the loss of vast areas of forest worldwide. At present, many developed countries are attempting to reverse these effects, establishing policies for the restoration of older woodland systems. Reforestation is a complex matter, planned and carried out by experts who need objective information regarding the type of forest that can be sustained in each area. This information is obtained by drawing up feasibility models constructed using statistical methods that make use of the information provided by morphological and environmental variables (height, gradient, rainfall, etc.) that partially condition the presence or absence of a specific kind of forestation in an area. The aim of this work is to construct a set of feasibility models for woodland located in the basin of the River Liébana (NW Spain), to serve as a support tool for the experts entrusted with carrying out the reforestation project. The techniques used are multilayer perceptron neural networks and support vector machines. Their results will be compared to the results obtained by traditional techniques (such as discriminant analysis and logistic regression) by measuring the degree of fit between each model and the existing distribution of woodlands. The interpretation and problems of the feasibility models are commented on in the Discussion section. 相似文献
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Armenteras Dolors Rodríguez Nelly Retana Javier Morales Mónica 《Regional Environmental Change》2011,11(3):693-705
Colombian Andean forests cover nine million ha. These forests provide an informative case study of mountain deforestation
in South America. They are surrounded by tropical lowland forests, and they host most of the country’s human population. This
study evaluates the relative importance of human and natural variables in deforestation of the Colombian Andes between 1985
and 2005 using remote sensing methods, geographic information system (GIS) technology and general linear models (GLM). The
following factors affected the annual deforestation in the region positively: forced population migration, unsatisfied basic
needs, economic activity, crops, pastures, illicit crops, protected areas and slope. Factors having a negative effect were
tenure of small land parcels, road density, water scarcity and mean temperature. The results of this study also provide insight
into the differences between the dynamics of lowland forests and those of montane forests. Montane forests had a lower annual
rate of deforestation than did forests in the lowlands. Socio-economic, demographic and biophysical factors explain overall
deforestation rates for the region. However, when altitude variation is taken into account, intraregional differences in the
Andes become evident. Deforestation processes differ between those areas adjacent to the high Andean valleys where most of
the country’s population concentrates and those areas in the tropical lowlands north, west and east of the Andean chain. Differences
between lowland and montane forest dynamics are due partly to the accessibility of forests and differences in wealth and economic
activities. In montane forests, deforestation is positively influenced by economic activity, the presence of protected areas
and higher slopes. Deforestation in montane forests is negatively affected by tenure of small land parcels, road density,
water scarcity and mean temperature. Lowland deforestation rates are more closely related to rural population, pasture percentage,
crops, protected areas and temperature. Our results suggest that montane forests appear to be in a more advanced stage of
colonisation and economic development, whereas lowland forests are closer to the colonisation frontier and to rapidly growing
colonist populations. This study reinforces the idea that although the most common tropical drivers of deforestation are found
in the Andes, these drivers operate differently when intraregional differences are considered. 相似文献
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Predicting and setting conservation priorities for Bolivian mammals based on biological correlates of the risk of decline 下载免费PDF全文
The recognition that growing proportions of species worldwide are endangered has led to the development of comparative analyses to elucidate why some species are more prone to extinction than others. Understanding factors and patterns of species vulnerability might provide an opportunity to develop proactive conservation strategies. Such comparative analyses are of special concern at national scales because this is the scale at which most conservation initiatives take place. We applied powerful ensemble learning models to test for biological correlates of the risk of decline among the Bolivian mammals to understand species vulnerability at a national scale and to predict the population trend for poorly known species. Risk of decline was nonrandomly distributed: higher proportions of large‐sized taxa were under decline, whereas small‐sized taxa were less vulnerable. Body mass, mode of life (i.e., aquatic, terrestrial, volant), geographic range size, litter size, home range, niche specialization, and reproductive potential were strongly associated with species vulnerability. Moreover, we found interacting and nonlinear effects of key traits on the risk of decline of mammals at a national scale. Our model predicted 35 data‐deficient species in decline on the basis of their biological vulnerability, which should receive more attention in order to prevent their decline. Our results highlight the relevance of comparative analysis at relatively narrow geographical scales, reveal previously unknown factors related to species vulnerability, and offer species‐by‐species outcomes that can be used to identify targets for conservation, especially for insufficiently known species. Predección y Definición de Prioridades de Conservación para Mamíferos de Bolivia con Base en Correlaciones Biológicas del Riesgo de Declinación 相似文献
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