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121.
The Wild Animal as a Research Animal   总被引:1,自引:0,他引:1  
Most discussions on animal experimentation refer to domesticated animals and regulations are tailored to this class of animals. However, wild animals are also used for research, e.g., in biological field research that is often directed to fundamental ecological-evolutionary questions or to conservation goals. There are several differences between domesticated and wild animals that are relevant for evaluation of the acceptability of animal experiments. Biological features of wild animals are often more critical as compared with domesticated animals because of their survival effects. An important issue is what is called here “natural suffering”: the suffering from natural circumstances. Should this type of suffering be taken into account when suffering from experimentation is evaluated? As an answer, it is suggested that ``natural functioning'' should be considered as an additional standard in the evaluation of wild animal experimentation. Finally, two topics related to the ecological context are considered. Firstly, the often inevitable involvement of non-research animals in wild animal experimentation, and secondly, the eco-centric approach to nature conservation. According to the latter position, animals are subordinated to ecosystems. All these aspects make the evaluation of wild animal experiments much more complex than experiments with domesticated animals. Preliminary scores are proposed to deal with these aspects. It is argued that this should not lead to a more complex governmental regulation, since an effective maintenance and control are hard to realize and one may loose the cooperation of researchers themselves. In addition, non-governmental professional organizations such as research societies and funding organizations play a pivotal role.  相似文献   
122.
对红外分光光度法测定水中动植物油的不确定度来源进行了分析,构造出合理的数学模型,确定了各输入量之间的关系,量化各分量后,合成得到满意的结果。从而提出,根据被测量及其所依赖的输入量之间的关系构造数学模型,并运用不同的评定方法对各个分量进行量化,可实现对某些检测项目不确定度的简化评定。  相似文献   
123.
东辽县畜禽养殖污染现状及对策研究   总被引:1,自引:0,他引:1  
根据第一次全国污染源普查成果,对东辽县畜禽养殖业污染现状进行了介绍,指出了畜禽养殖污染主要是专业化畜禽养殖造成的,专业化畜禽养殖污染是农村面源污染的主要来源,已成为影响环境质量的重要因素。据此,提出了防治畜禽养殖污染的对策。  相似文献   
124.
青藏高原农牧业生态风险时空变化特征与分区防控   总被引:1,自引:0,他引:1  
青藏高原地区是我国重要的生态安全屏障、战略资源储备基地,农牧业是青藏高原涵盖范围最广的产业,明晰其生态风险对实现青藏高原农牧业可持续发展具有重要意义。构建了青藏高原农牧业生态风险评价体系,并以216个县域为评价单元,分析1990—2015年农牧业开发综合生态风险的时空分布及其重心转移规律,并结合区域农牧业开发强度实现农牧业生态风险权衡分区。结果表明:(1)青藏高原综合生态风险总体有上升趋势,呈“东部多核聚集、西部零星散列”的分布格局。(2)风险重心向西北方向移动,风险主趋势方向转为西北—东南走向。(3)青藏高原限制开发区面积占比最大为50.84%,其次为发展预警区与自然恢复区,青藏高原整体农牧业开发强度较高,应在保障高原生态安全屏障功能的情况下减缓农牧业开发。针对区域特征提出农牧业发展方案,以期为青藏高原地区农牧业开发生态风险防范及发展规划提供科学指引。  相似文献   
125.
分析了监测县涝洼农区发展节粮型畜牧业的有利条件和存在的问题,提出了充分利用本地自然资源,发展节粮型畜牧业的对策。  相似文献   
126.
本研究以经济底栖生物菲律宾蛤仔和河蚬为受试生物,分别对不同浓度梯度的海洋和淡水底泥中9种代表性有机氯农药(OCPs)进行累积实验;同时采用Tenax连续萃取法研究2类底泥中OCPs的脱附动力学,提供简单、快速评价养殖底泥中OCPs生物有效性的方法,并将Tenax萃取结果与2种底栖生物的累积结果进行比较。结果表明,菲律宾蛤仔和河蚬对OCPs的生物-底泥富集因子(BSAF)分别为0.31~1.89和0.12~2.12,且底泥中有机碳标化的OCPs浓度与生物体内脂肪标化的OCPs浓度之间的相关性较差。Tenax脱附动力学的结果表明,2类底泥中OCPs的快速脱附比例(F_(rap))均在50%左右,其快速、慢速和极慢速脱附速率常数数量级分别为10~(~(-1))、10~(-2)和10~(-4)。Tenax快速脱附组分与2种底栖生物累积结果之间具有良好的相关性(r~2=0.75,P0.0001),表明Tenax萃取技术可以预测OCPs在底栖生物体内的累积量,并且该方法克服了大型底栖生物累积实验结果重复性较差等缺点。另外通过与基于热力学平衡的方法对比发现,Tenax萃取技术更适用于滤食性或可消化底泥的底栖生物对底泥污染物的富集;同时Tenax 6 h和24 h单点萃取技术可以作为简单快速评价底泥疏水性有机污染物(HOCs)生物有效性的替代方法,进一步为养殖领域的底泥污染状况以及相关水产品的质量安全和食用风险提供生物有效性评价依据。  相似文献   
127.
Quantum mechanic computer models are often used in chemistry to predict properties of molecules and to simulate reaction pathways. Such models calculate bond lengths, bond angles, dihedral angles, the energy of the molecular‐orbitals (MO's), the dipole moment, the ionisation potential, and the heat of formation. These results lead to detailed information on electronic structures like bond orders, electronic charges and levels of frontier orbitals (HOMO, LUMO).

It is possible to calculate properties of ground state molecules as well as ionic and radicalic structures, or reaction intermediates and other compounds with very short lifetimes.

From the exact knowledge of electronic structure, frontier orbitals, and reaction intermediates it is possible to predict stability of chemicals in the environment but also of fictive chemicals, which are not yet synthesized. Some authors have shown that there are correlations between electronic structure and toxicity.

The most interesting models for environmental chemistry are semiempirical models, such as MINDO, MNDO or MOPAC. Theses programs are able to handle molecules with 30 and more heavy atoms (all elements without hydrogen), and it is possible to install them on main frame computers (CPU‐time several minutes to hours) and on personal computers, with coprocessors (CPU‐time several hours to a few days).

Normally the molecule is read in from a Z‐matrix (a matrix of polar coordinates of atoms connected in the molecule) and with symmetry data. Furthermore, programs are available which create a Z‐matrix from the molecular structure plotted on the screen with a mouse.  相似文献   
128.
廉同辉  袁勤俭 《自然资源学报》2013,28(10):1827-1834
国际标准产业分类体系是目前国际上最有影响和权威的产业分类体系。深入了解国际标准产业分类体系中农、林、牧、渔业分类演化,对正确收集、处理和测算我国农、林、牧、渔业的指标以及国际间数据比较至关重要。论文首先详细地剖析国际标准产业分类体系的农、林、牧、渔业的分类演化,然后依据国际标准产业分类体系的最新变化,结合我国农、林、牧、渔业现状,为我国国民经济行业分类中农、林、牧、渔业的修改和调整提供建议。  相似文献   
129.
It is observed that 1?→?3-β-glucan, a major cell wall component of fungi, induces pulmonary inflammation. There is inconsistency in determining the correlation between the levels of glucan measured by current extraction methods and the respiratory inflammation observed in individuals or lab animals exposed to environmental dust samples. The glucan-specific limulus amebocyte lysate (G-LAL) method was used after extraction with dimethyl sulfoxide (DMSO) or sodium hydroxide (NaOH) to analyze the glucan content of office dust samples collected from a water-damaged building. C3HeB/FeJ mice, an endotoxin-sensitive strain, were treated with different dust samples (2.5?mg?kg?1 body weight) or saline (vehicle control) by pharyngeal aspiration. At 1?day after aspiration, bronchoalveolar lavage (BAL) was performed, and lung inflammation and injury were assessed by measuring: (1) neutrophil (PMN) infiltration, (2) inflammatory cytokine (IL-6, IL-10, MCP-1, IFN-γ, TNF-α, and IL12-p70) levels, and (3) albumin and lactate dehydrogenase in recovered BAL fluid. Both DMSO and NaOH extraction increased the detection of glucan by approximately 20-fold compared to water extraction. However, only the DMSO extraction method showed a statistically significant positive correlation between 1?→?3-β-glucan and albumin levels, total numbers of BAL, polymorphonuclear leukocytes (PMNs) cells recovered, levels of TNF-α, MCP-1, and IL-6. In conclusion, 1?→?3-β-glucan is a potent inflammatory agent in dust samples and DMSO extraction for glucan analysis may prove useful in understanding the impact of environmental contamination by glucans on lung disease.  相似文献   
130.
Contents and changes of some hazardous elements in 388 animal feed and manure samples collected in 2009–2010 from 194 animal farms in 10 provinces of China were determined. The concentrations of Cu, Zn, Cr, and Pb in animal manures were in the ranges of 10–1800, 50–6300, 0.1–340, and 1.0–310 mg kg?1, with median concentrations of 200, 500, 15, and 11 mg kg?1, respectively. As, Cd, and Hg were in ranges from undetectable to 280, undetectable to 10, and 0.01–2.5 mg kg?1, respectively. The concentrations of Cu, Zn, and As were highest in the manure from pig, followed by the manure from poultry and dairy cows. From 1990 to 2010, Cu, Zn, As, Cd, and Cr contents in manure increased strongly, especially in pig and poultry manure. Most of the increases occurred before 2003 and then stabilized or decreased which reflects the extensive use of feed additives before 2003 and the gradual stabilization since then.  相似文献   
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