一种改进的齿突蟾动物肌肉线粒体DNA提取方法

以1号冷冻保存(-20℃)的齿突蟾标本为材料,建立一种动物肌肉线粒体DNA的快捷提取方法.取10 g冷冻保存的肌肉组织,在研钵中剪碎,液氮研磨成粉;然后加SE缓冲液混匀,转入10 mL离心管静置10 min;上清液转入2 mL的Eppendorf管,1 000×g离心10 min,取上清液,再12 000×g离心15 min,沉淀即为线粒体;最后用SDS碱裂解法分离得到mtDNA.图1参3     

三波长红外法测定水中石油类和动植物油

根据油的种类，性质及水中的分布情况，采用优级纯四氯化碳多次萃取，将油从水中提取出来，包含石油类和动物物油，动物物油属极性物质，可被硅酸吸附，石油类不被吸附，在红外三波长，波数分别为2930cm^-1,2960cm^-1,3030cm^-1处被吸收，准确测定这三个波数特征谱带的总和，从而准确测定水中石油类和动植物油。     

SIMULATING NITROGEN LOSSES FROM AGRICULTURAL LAND: IMPLICATIONS FOR WATER QUALITY AND PROTECTION POLICY1

ABSTRACT: EPIC, a soil erosion/plant growth simulation model, is used to simulate nitrogen losses for 120 randomly selected and previously surveyed cropland sites. Simulated nitrogen losses occur through volatilization, surface water and soil runoff, subsurface lateral flow, and leaching. Physical and crop management variables explain a moderate but significant proportion of the variation in nitrogen losses. Site slope and tillage have offsetting effects on surface and ground water losses. Nitrogen applications in excess of agronomic recommendations and manure obtained off the farm and applied to the sites are significant contributors to nitrogen losses. Farm characteristics such as production of confined livestock, total manure nitrogen available, and farm income per cropland acre explain a relatively large portion of the variability in manure nitrogen applied to survey sites. The results help to identify farm characteristics that can be used to target nutrient management programs. Simulation modeling provides a useful tool for investigating variables which contribute to agricultural nitrogen losses.     

Exploratory behavior and the welfare of intensively kept animals

Exploratory behavior is considered under the following categories: (1) extrinsic exploration in which the animal seeks information about conventional reinforcers such as food, (2) intrinsic exploration which is directed toward stimuli which may have no biological significance, further divided into inspective and inquisitive exploration. In the former the animal inspects a particular object; in the latter, the animal performs behavior to make a change in its environment, rather than merely responding to a change. Extrinsic exploration is synonymous with the ethological term, appetitive behavior. It is shown that much of the behavior indicative of frustration reported in intensively housed animals occurs when the appetitive component of a drive rather than the consummatory component, is prevented. Consideration of inspective exploration is necessary for good husbandry practice, for fear is an important competing response. Inquisitive exploration has not been widely investigated in infraprimate species, but the authors present several possible examples in the species of common agricultural animals. However, they suggest that the propensity to show this type of exploration may vary between closely related species. In environments barren to the extent of stifling exploration, animals may develop apathy, and its relevance to animal welfare is discussed.     

Effects of Management of Domestic Dogs and Recreation on Carnivores in Protected Areas in Northern California

Abstract: In developed countries dogs (Canis lupus familiaris) are permitted to accompany human visitors to many protected areas (e.g., >96% of protected lands in California, U.S.A.), and protected‐area management often focuses on regulating dogs due to concerns about predation, competition, or transmission of disease and conflicts with human visitors. In 2004 and 2005, we investigated whether carnivore species richness and abundance were associated with management of domestic dogs and recreational visitation in protected areas in northern California. We surveyed for mammalian carnivores and human visitors in 21 recreation areas in which dogs were allowed offleash or onleash or were excluded, and we compared our observations in the recreation areas with observations in seven reference sites that were not open to the public. Carnivore abundance and species richness did not differ among the three types of recreation areas, but native carnivore species richness was 1.7 times greater (p < 0.01) and the relative abundances of native coyotes (Canis latrans) and bobcats (Lynx rufus) were over four times greater (p < 0.01) in the reference sites. Abundances of bobcats and all carnivores declined as the number of visitors increased. The policy on domestic dogs did not appear to affect species richness and abundance of mammalian carnivores. But the number of dogs we observed was strongly associated with human visitation (R²= 0.54), so the key factors associated with recreational effects on carnivores appear to be the presence and number of human visitors to protected areas.     

Research Training for Releasable Animals

Abstract:  Restrictions on training potentially releasable animals such as those undergoing rehabilitation care or wild-caught captives have limited our understanding of sensory processes, cognition, and physiology important for conservation of species. It is common practice among several U.S. federal agencies to limit training of animals available for release. The behavioral argument justifying this practice is that training habituates subjects to people and conditions them to associate people with rewards such as food; habituation to and positive associations with people will lead animals into dangerous situations after their release. If under special circumstances research training is permitted, all trained behaviors must be extinguished before release because behaviors will transfer to the natural setting. Research on animal learning and memory indicates that these may not be accurate scenarios. A review of the literature on habituation, classical and instrumental conditioning, and compound conditioning suggests that learning within a research setting does not add to learning that already occurs in procedures associated with basic feeding and care. In fact, animals probably learn less about people in a training setting. Furthermore, context-specific effects on memory limit behavior transfer from captive to natural settings. Extinction is strongly susceptible to context effects, which suggests that extinction does not effectively transfer to the postrelease setting. Counterintuitively, extinction of responses to experimental stimuli under some circumstances may enhance undesirable learning about humans. Under those circumstances in which isolation from human contact is difficult or undesirable, behavioral research can present an ideal format for minimizing learning about humans and provide biological information important for conservation.     

清初“摊丁入亩”政策对环境的影响

清初“摊丁入亩”政策对清社会经济的恢复发展确实起到了促进作用,但同时对环境也构成了巨大威胁,引发了地表植被遭严重玻坏、自然灾害频繁、珍稀野生动植物大量灭绝等一系列环境问题。剖璞见玉,对今有史鉴作用。     

Variation in Population Parameters: Adaptation to Toxic Environmental Factors

Some mechanisms of adaptation of natural populations to toxic environmental factors are discussed. The dandelion and hole-nesting birds are used as examples for demonstrating that an increase in the variation of reproductive parameters upon chemical environmental pollution favors the survival of those individuals in the populations that are better adapted to changes in the climate and other environmental conditions. The increased variation in reproductive parameters may promote the elimination of less fit individuals from populations. The ensuing energy loss is the cost of maintaining the population size in the chemically degraded environment.     

Ethics, Science, and Antimicrobial Resistance

The issue of regularly feeding low levels of antibiotics to farm animals in order to increase productivity is often portrayed as a dilemma. On the one hand, such antibiotic use is depicted as a necessary condition for producing cheap and plentiful food, such that were such use to stop, food prices would rise significantly and our ability to feed people in developing nations would decrease. On the other hand, such antibiotic use seems to breed antibiotic resistance into pathogens affecting human health. Resolving this dilemma, it is alleged, will require great amounts of research into risk/benefit assessment. Contrary to this claim, we will argue that society has all the data it needs to make a reasonable ethical decision, which would be curtailing such use. Such curtailment will not harm consumers significantly, will not harm developing nations' evolving agriculture, and could produce hitherto unnoticed benefits, namely restoring the possibility of a more husbandry-based, sustainable agriculture to replace the high-tech agriculture that has hurt animals, the environment, small farms, and sustainability.     

Outlining a Conception of Animal Welfare for Organic Farming Systems

The concept of animal welfare refersto the animal's quality of life. The choice ofdefinition always reflects some basicvaluation. This makes a particular conceptionof welfare value-dependent. Also, the animalhusbandry system reflects certain values oraims. The values reflected in the chosenconception of animal welfare ought tocorrespond to values aimed for in the husbandrysystem. The IFOAM Basic Standards and otherwritings dealing with organic animal husbandryshould be taken as a departure point for adiscussion of how to interpret the conceptionof welfare in organic farming systems. Theconception of welfare is related to two corevalues in the organic agriculture movement.These core values should be considered in termsof (1) aim for holistic view and (2) aim forsustainability. A third, implicit core value,based on bio- and ecocentric views: (3) respectfor nature is needed as a supplement to thesetwo core values. There are importantimplications of these core values for an``organic' conception of animal welfare and forconfronting two dilemmas due to conflictinginterests. Comparisons among the three commonlyused welfare definitions will show thesuperiority of the third approach, which canprovide an outline for a conception of animalwelfare more suitable for organic farmingsystems. This outline combines a holisticecocentric approach with respect for theindividual animal, and it can be used as thebasis for a complex definition with emphasis onnatural behavior. Such a systemic approachconsiders welfare in relation to differentsystemic levels. The systemic view also offerspossibilities for resolving the dilemmas in newways.