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Media characterizations of zoo and aquarium animal deaths were randomly monitored on the internet for a 20‐month period (September 2003–May 2005). Based on 148 samples collected, it was possible to classify articles into one of four categories, which were operationally defined: 1) dispassionate observers; 2) accusers; 3) sympathizers; and 4) balancers. In addition, with the notable exception of seven cases, all of the articles examined focused on large, charismatic mammals, such as gorillas, dolphins, lions, and elephants. Although a majority of the articles examined (70.4%) were either dispassionate and objective or sympathetic, nearly a third (29.6%) were either accusatory or attempted to balance the accusatory statements of animal rights activists with sympathetic statements from zoo professionals. Recommendations are offered for how zoos should deal with the increasing media and public interest in zoo animal deaths, including: 1) a greater commitment to studying the reasons for mortality in a wide variety of species; and 2) an increased investment in record keeping and analysis, which should allow zoos to calculate average life spans in animal populations and to monitor and assess the risk of certain lethal diseases on a real‐time basis. Comparisons are drawn between zoo veterinary practices and human medicine, which are both inexact sciences. Suggestions are made for how the public and key decision‐makers can distinguish between media reports on zoo animal deaths that are legitimate cause for concern vs. those that are sensationalist and meant to generate controversy and sell papers. A greater focus on the science of zoo animal death is necessary for accredited zoos to maintain the public's confidence in their animal care practices. Zoo Biol 0:1–15, 2006. © 2006 Wiley‐Liss, Inc.  相似文献   

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The reality of ecological and local races was investigated in two widespread Palearctic species of lymnaeid snails (Lymnaea stagnalis and Radix auricularia). Several methods of statistical analysis were used, including two-way ANOVA, cluster analysis, and discriminant analysis for six plastic shell characters. It was shown that none of the methods used could convincingly demonstrate that ecological and local races were present in the studied species. Even in cases when statistically significant differences among the populations in the morphology of shells were revealed, these differences were very small and did not correspond to the meaning that was put into the concept of “race” by malacologists in the past. Perhaps, the formation of such races in pond snails is possible only in case of populations being formed in suboptimal conditions, for example, in thermal springs or at large depths. This being the case, the distinguishing of races requires using other shell characters, both quantitative and qualitative ones.  相似文献   

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History, Power, Ideology: Central Issues in Marxism and Anthropology. Donald L. Donham. Berkeley: University of California Press, 1999. 240 pp.  相似文献   

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Transition state dissociation constants are currently considered, utilizing stopped flow equipment. The underlying theory is briefly reviewed, relating the ideas to steady state kinetics of enzyme systems. The ideas are further analyzed under the consideration of chemical relaxation. Test conditions are described which would allow an investigation of the concepts of transition state dissociation constants by chemical relaxation techniques. A discussion concerning the way in which the concepts of transition state dissociation constants relate to other theories which assume short-lived, but real, dissociation constants is included. The theory is rigorously analyzed (in a second part), revealing the nature of the assumption of a transition state dissociation constant: While they may be written in a formal manner, they are not based on reality—on kinetic grounds direct interconversions between transition states are practically impossible. This applies also to transition state dissociation constants involving protons.  相似文献   

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Viruses are known to be abundant, ubiquitous, and to play a very important role in the health and evolution of life organisms. However, most biologists have considered them as entities separate from the realm of life and acting merely as mechanical artifacts that can exchange genes between different organisms. This article reviews some definitions of life organisms to determine if viruses adjust to them, and additionally, considers new discoveries to challenge the present definition of viruses. Definitions of life organisms have been revised in order to validate how viruses fit into them. Viral factories are discussed since these mini-organelles are a good example of the complexity of viral infection, not as a mechanical usurpation of cell structures, but as a driving force leading to the reorganization and modification of cell structures by viral and cell enzymes. New discoveries such as the Mimivirus, its virophage and viruses that produce filamentous tails when outside of their host cell, have stimulated the scientific community to analyze the current definition of viruses. One way to be free for innovation is to learn from life, without rigid mental structures or tied to the past, in order to understand in an integrated view the new discoveries that will be unfolded in future research. Life processes must be looked from the complexity and trans-disciplinarity perspective that includes and accepts the temporality of the active processes of life organisms, their interdependency and interrelation among them and their environment. New insights must be found to redefine life organisms, especially viruses, which still are defined using the same concepts and knowledge of the fifties.  相似文献   

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Summary 1. There are numerous circumstantial evidence supporting the concept that steroid hormones control cellular function by means other than the nuclear receptor steroid binding mechanism. It is the intent of this report to present evidence indicating that steroids bind to specific sites in neuronal membranes.2. Some of the criteria to define steroid membrane receptors using steroid-BSA conjugates that can be radioiodinated to desired specific activity have been fulfilled for each of the three sex steroids using crude synaptosomal membrane preparations (P2 fractions) from the CNS of female and male rats. Ligand binding for each of the three steroids indicate high-affinity and high-capacity sites with distinct brain selectivity and stereospecificity. For example, 17-E-6-[125I]BSA binds hypothalamic P2 fractions (HYP-P2) with an estimatedK d of about 3±0.7 nM (X ± SE;n=3), whereas the cerebellum P2 (CB-P2) fractions bind the ligand with aK d of 34±7 nM and, aB max of 3 and 42 pmol/mg protein, respectively. Estrogen and testosterone binding fit best a one-single site, while progesterone binding sites can be best represented by a two-binding site, one high-affinity (K d=1–2 nM) and one low affinity (K d=62 nM), in CB-P2 fractions from intact adult female rat brain. Kinetics studies for T-3-[125I]BSA indicate that the estimatedK d of 30±2 nM for the olfactory bulb P2 fractions (OB-P2) from male rats is in good agreement withK d values computed from Scatchard-derived data using the LIGAND algorithm.3. 17-E-6-[125I]BSA binding sites are stereospecific and appears to be present as early as 5 days of age in both the OB- and the CB-P2 fractions without changes during development. In contrast, P-6-[125I]BSA binding sites are practically absent during days 5 and 12 and appear by day 22.4. Finally, membrane receptor molecules for estrogen and progesterone have been isolated and purified by affinity chromatography and characterized by PAGE and Western blot. Microsequencing of one of the membrane estrogen binding proteins indicates that the high-affinity site corresponds to the OSCP subunit of the proton ATP synthase.5. It remains to be determined if P and T also bind to this complex enzyme or if they bind to other subunits of the family of proton ATPases. Overall the data indicate that steroid hormones conjugated to BSA are important tools to study the reality of membrane steroid receptors.  相似文献   

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In this article, I will analyse the conduct of the Brazilian legislative process regarding new reproductive technologies, mainly the moral assumptions of three categories that are essential to the debate: the status of the child generated by these techniques; the number of embryos transferred in each cycle (as well as foetal reduction); and the issue of women's eligibility for such techniques. The analysis will be a sociological study of the Brazilian legislative debate, using feminist perspectives in ethics as the theoretical reference. The focus will be the bills in progress in the Brazilian National Congress, the public and official declarations of legislators involved in the issue and the regulation of the medical class, which has influenced the legislative process. Aside from the analysis of the legislative process, I include a section on the justification of these bills, since that is where the legislator exposes what he/she believes is the moral support for the bill.  相似文献   

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Compartmentation: model and reality   总被引:1,自引:0,他引:1  
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Several ambitious restoration targets have been set for recovering degraded ecosystems in Brazil (21 million hectares with a legal deficit of native vegetation). The development of scientific knowledge and skilled professionals is necessary to meet this demand and is fundamental for achieving success in medium‐ and long‐term restoration. In this study, we describe the availability and profile of postgraduate courses on ecological restoration in Brazil. We surveyed 272 postgraduate programs, comprising six specific areas of concentration (forestry, soil sciences, botany, environmental engineering, ecology, and environmental science). We analyzed all selected courses in terms of location, approach (economic, social, and legal), and restoration techniques. Only 27% of the postgraduate programs analyzed offer ecological restoration courses, and 49% of these are offered in the southeast region of the country. Regions covered by nonforest ecosystems, such as Pampas, Caatinga, and Pantanal, were poorly represented. Legal aspects were considered in 51% of the courses, whereas social and economic approaches were only considered in 2.7 and 11% of the courses, respectively. Seedling planting (85%) and nucleation (68%) were the most frequently cited techniques of active restoration, and passive restoration was mentioned in 63% of the courses. Our findings highlight the need for increasing postgraduate courses in areas with nonforest ecosystems, especially due to a lack of knowledge about restoration of these areas. The incorporation of economic and social approaches is highly recommended, considering the importance of these attributes in achieving success in large‐scale restoration initiatives.  相似文献   

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Brazil has one of the greatest bird diversities in the world, with around 1,800 species. However, many species are now threatened by illegal capture and trade that is largely driven by the culture of keeping wild birds as pets. This study documents the nature and purpose of bird capture and trade in the semi-arid Caatinga biome in northeastern Brazil, which has around 510 bird species and a population of around 25 million people. Data were obtained through observation in the homes of bird keepers and at open air markets, as well as through semi-structured and open-ended interviews and informal conversations with 52 wild bird keepers. We recorded 38 species of birds kept as pets in this study. The family with the largest number of species recorded was the Emberizidae (29%), followed by the Columbidae (16%) and the Psittacidae (16%). The most frequently kept species were: Paroaria dominicana, Aratinga cactorum, Icterus jamacaii, Sporophila albogularis, Turdus rufiventris and Cyanocompsa brissonii, which are all native to this region. Among the recorded species, only Pintassilgo (Carduelis yarrellii) is listed as an endangered species in Brazil. Of the people interviewed, 32% observed a reduction in abundance, or disappearance, of several bird species in the region. The need for measures aimed at the sustainability of wild avifauna use is therefore evident. These include law enforcement, commercial breeding and environmental education, of which the last is considered the most likely to be effective.  相似文献   

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