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1.
National Park of Tijuca in Rio de Janeiro (Brazil) is about 3,300 ha and considered the largest urban forest in the world. Its floristic composition is typical of Atlantic Rain Forest. The reserve is being altered because of fire occurrences and urban expansion. This study identified locations and causes of forest fires, and makes management recommendations to restore damaged areas. From 1991 to 2000, forest firefighters recorded an average of 75-fire occurrences/year. Identified causes included hot air balloons (24%), intentional (24%), rubbish burning (21%) and religious practices (17%). Primary fuels included invasive grasses and ferns. Although hot air balloons destroyed larger areas of forest in each occurrence, a greater number of fires started in the invasive vegetation along roads that bisect the forest. In response to recurrent forests, invasive vegetation has spread gradually into the forest increasing forest degradation. To decrease fire damage, sites with high fire frequencies and density of invasive vegetation were planted with less flammable species. Results indicate that fire frequency decreased and density of invasive vegetation declined. This approach appears to prevent fire incidence, reduce the need for fire fighting, and preserve existing biodiversity.  相似文献   
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论文在讨论四个移民典型案例的基础上 ,讨论在项目中与政策相关的教训  相似文献   
3.
Two habituation experiments were conducted to investigate how 4‐month‐old infants perceive partly occluded shapes. In the first experiment, we presented a simple, partly occluded shape to the infants until habituation was reached. Then we showed either a probable completion (one that would be predicted on the basis of both local and global cues) or an improbable completion. Longer looking times were found for the improbably completed shape (compared to probable and control conditions), suggesting that the probable shape was perceived during partial occlusion. In the second experiment, infants were habituated to more ambiguous partly occluded shapes, where local and global cues would result in different completions. For adults, the percept of these shapes is usually dominated by global influences. However, after habituation the infants looked longer at the globally completed shapes. These results suggest that by the age of 4 months, infants are able to infer the perceptual completion of partly occluded shapes, but for more ambiguous shapes, this completion seems to be dominated by local influences.  相似文献   
4.
The concept of integration is not well defined. It not known how people with disabilities experience integration. In this study qualitative methods were used. The aim of the article is to define a model of successful integration based on the perspectives of people with disabilities and people within their social environment. Integration consists of five elements: functioning ordinarily without receiving special attention, mixing with others that are not disabled, taking part in society, trying to realize one’s potential and directing one’s own life. Integration is obtained through a process of interaction between a person with a disability and society. This process is influenced by personal, societal and support factors. The individual with a disability and society have a mutual responsibility with respect to integration.  相似文献   
5.
价值观的形成有其自身的规律 ,并受到社会因素和个体内在因素的影响。当代青年正处在我国改革开放进一步深化和社会主义市场经济体制逐步确立及自我意识发展和自我需要扩大的时期 ,因此 ,他们的价值观必然打着当今时代的烙印 ,具有开放性、先锋化、情绪性等特点 ,他们追求高效、公正、互利 ,追求求职与成才相结合 ,但同时 ,其自身的身心失范问题也日趋严重。  相似文献   
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An analysis of 120 corporate websites from Denmark, France, Germany, Norway, Singapore, Spain, the United Kingdom and the United States reveals, for the first time, international results about the implementation and use of virtual press rooms. This article shows the importance that large international companies attribute to Web-based media centers to achieve organizational objectives and to meet journalists’ demands for information and audiovisual resources. The study also shows, however, that most press rooms are far from being complete, efficient, easy-to-use, reliable and updated on a daily basis. In fact, there is not a single country from those analyzed that consistently stands out from the rest. In most of them, good results in certain areas coexist with significant shortcomings in others, resulting in some cases in poor press rooms that may not achieve the desired public relations objectives.  相似文献   
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苏轼一生无论居庙堂之高 ,或处江湖之远 ,皆追求心灵自由 ,达到了物我同一、高凡绝尘的理想境界。该文认为苏轼慕陶、学陶 ,作《和陶诗》12 0余首以明志 ,却始终未能像陶渊明那样挂冠而去 ,归隐田园。究其原因 ,不外乎生活时代、出身背景、思想体系、入仕经历等方面的差异  相似文献   
10.
Oja (1983) examined various ways of measuring location, scatter, skewness, and kurtosis for multivariate distributions. Among other measures of location, he introduced a generalised median known in this paper under the name of the Oja median. In our study of the existence of that median, we show that Oja's definition can only be applied to distributions having a mean. In dimension d θ 2, we establish that the usual method of extension breaks down, which raises the question of the validity of the concept as a notion of median. Two fundamental theoretical properties of that median are also considered: uniqueness and consistency.  相似文献   
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