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1.
True navigation and magnetic maps in spiny lobsters   总被引:1,自引:0,他引:1  
Boles LC  Lohmann KJ 《Nature》2003,421(6918):60-63
Animals are capable of true navigation if, after displacement to a location where they have never been, they can determine their position relative to a goal without relying on familiar surroundings, cues that emanate from the destination, or information collected during the outward journey. So far, only a few animals, all vertebrates, have been shown to possess true navigation. Those few invertebrates that have been carefully studied return to target areas using path integration, landmark recognition, compass orientation and other mechanisms that cannot compensate for displacements into unfamiliar territory. Here we report, however, that the spiny lobster Panulirus argus oriented reliably towards a capture site when displaced 12-37 km to unfamiliar locations, even when deprived of all known orientation cues en route. Little is known about how lobsters and other animals determine position during true navigation. To test the hypothesis that lobsters derive positional information from the Earth's magnetic field, lobsters were exposed to fields replicating those that exist at specific locations in their environment. Lobsters tested in a field north of the capture site oriented themselves southwards, whereas those tested in a field south of the capture site oriented themselves northwards. These results imply that true navigation in spiny lobsters, and perhaps in other animals, is based on a magnetic map sense.  相似文献   

2.
建设社会主义和谐社会,必须正确地理解社会个体的和谐。和谐社会个体的含义为个体在专业化基础上的全面发展。和谐社会个体的标准表现为富足协调的物质与精神生活、高度完善的文化素养、健康的人格结构。和谐社会个体的实现途径主要是培育公平的价值实现环境。  相似文献   

3.
科学开展艾滋病预防干预工作   总被引:7,自引:0,他引:7  
回顾分析了艾滋病检测和监测、感染者及其配偶通知、知识宣传与行为干预、暗娼体检与发放健康证、感染者管理等策略在艾滋病防治实践中存在的问题;讨论了匿名与实名检测、通知与不通知感染者配偶、正确理解和区分防病知识水平与健康行为改变的关系、是否可以通过为娱乐场所服务人员发放体检证以控制艾滋病流行、采用感染者集中管理的利弊等,为科学开展艾滋病预防干预工作、提高实际防治效果提出了建议。  相似文献   

4.
Paz-Y-Miño C G  Bond AB  Kamil AC  Balda RP 《Nature》2004,430(7001):778-781
Living in large, stable social groups is often considered to favour the evolution of enhanced cognitive abilities, such as recognizing group members, tracking their social status and inferring relationships among them. An individual's place in the social order can be learned through direct interactions with others, but conflicts can be time-consuming and even injurious. Because the number of possible pairwise interactions increases rapidly with group size, members of large social groups will benefit if they can make judgments about relationships on the basis of indirect evidence. Transitive reasoning should therefore be particularly important for social individuals, allowing assessment of relationships from observations of interactions among others. Although a variety of studies have suggested that transitive inference may be used in social settings, the phenomenon has not been demonstrated under controlled conditions in animals. Here we show that highly social pinyon jays (Gymnorhinus cyanocephalus) draw sophisticated inferences about their own dominance status relative to that of strangers that they have observed interacting with known individuals. These results directly demonstrate that animals use transitive inference in social settings and imply that such cognitive capabilities are widespread among social species.  相似文献   

5.
把成年染病个体分为轻度染病个体和重度染病个体两个阶段,同时考虑了一种饱和形式的输入函数,建立了一类阶段结构的传染病模型.通过Hurwitz判据、构造Lyapunov函数的方法分析了系统平衡点的存在性和稳定性,并且发现当满足一定条件时,系统将发生Hopf分支.  相似文献   

6.
摘要:目的 2019 年 12 月暴发的新型冠状病毒( SARS-CoV-2) 迅速传播,严重影响了社会生活正常运行。 由于新型冠状病毒受体血管紧张素转化酶( ACE2)在人及动物中的保守性,有必要对常见家畜及实验动物的易感性进行评估。 方法 基于 ACE2 的氨基酸序列,分析其在人、实验动物及家畜等动物中进化关系;根据冠状病毒受体结合结构域( Receptor binding domain,RBD)与 ACE2 的结合位点,比较其在物种间的变化,推测不同物种对新型冠状病毒的易感性。 结果 新型冠状病毒与 ACE2 的结合位点在不同物种间较为保守,且 ACE2 受体与新型冠状病毒RBD 的结合位点在人、猴和仓鼠的完全一致。 结论 基于位点比较和 SARS-CoV-2 感染动物特性分析,猴和仓鼠可能对新型冠状病毒较为易感,可以优先选择它们作为 SARS-CoV-2 感染动物模型。  相似文献   

7.
Effective leadership and decision-making in animal groups on the move   总被引:9,自引:0,他引:9  
Couzin ID  Krause J  Franks NR  Levin SA 《Nature》2005,433(7025):513-516
For animals that forage or travel in groups, making movement decisions often depends on social interactions among group members. However, in many cases, few individuals have pertinent information, such as knowledge about the location of a food source, or of a migration route. Using a simple model we show how information can be transferred within groups both without signalling and when group members do not know which individuals, if any, have information. We reveal that the larger the group the smaller the proportion of informed individuals needed to guide the group, and that only a very small proportion of informed individuals is required to achieve great accuracy. We also demonstrate how groups can make consensus decisions, even though informed individuals do not know whether they are in a majority or minority, how the quality of their information compares with that of others, or even whether there are any other informed individuals. Our model provides new insights into the mechanisms of effective leadership and decision-making in biological systems.  相似文献   

8.
Vignal C  Mathevon N  Mottin S 《Nature》2004,430(6998):448-451
According to the social intelligence hypothesis, social context represents an important force driving the selection of animal cognitive abilities such as the capacity to estimate the nature of the social relationships between other individuals. Despite this importance, the influence of this force has been assessed only in primates and never in other animals showing social interactions. In this way, avian communication generally takes place in a network of signallers and receivers, which represents an audience altering individual signalling behaviours. Indeed, vocal amplitude and repertoire are known to be socially regulated and the attitude towards the opposite sex may change depending on the audience. This 'audience effect' provides support for the reality of social awareness in some bird species. However no evidence has yet been found to suggest that birds are able to estimate the characteristics of the social relationships between group-mates. Here we show that the male of a gregarious songbird species--the zebra finch (Taeniopygia guttata)--pays attention to the mating status of conspecific pairs, and uses this information to control its behaviour towards its female partner.  相似文献   

9.
Hamlin JK  Wynn K  Bloom P 《Nature》2007,450(7169):557-559
The capacity to evaluate other people is essential for navigating the social world. Humans must be able to assess the actions and intentions of the people around them, and make accurate decisions about who is friend and who is foe, who is an appropriate social partner and who is not. Indeed, all social animals benefit from the capacity to identify individual conspecifics that may help them, and to distinguish these individuals from others that may harm them. Human adults evaluate people rapidly and automatically on the basis of both behaviour and physical features, but the ontogenetic origins and development of this capacity are not well understood. Here we show that 6- and 10-month-old infants take into account an individual's actions towards others in evaluating that individual as appealing or aversive: infants prefer an individual who helps another to one who hinders another, prefer a helping individual to a neutral individual, and prefer a neutral individual to a hindering individual. These findings constitute evidence that preverbal infants assess individuals on the basis of their behaviour towards others. This capacity may serve as the foundation for moral thought and action, and its early developmental emergence supports the view that social evaluation is a biological adaptation.  相似文献   

10.
社会保障是一个国家(地区)和谐稳定发展的重要基石,适度的社会保障水平是经济持续稳定发展的基本保证.结合社会保障适度水平模型与社会保障最优支出模型,对重庆市的社会保障支出进行实证分析,发现重庆市社会保障实际支出未到达适度水平下限值,同时测算出2001—2010年和2011—2020年重庆市的社会保障最优水平分别为7. 82%和9. 68%.最后分别从政府、企业和个体角度对重庆市社会保障和经济持续健康发展提出了对策建议.  相似文献   

11.
环境行为学的城市认知地图理论,对于我们研究社会个体人对社会的认识很有启发意义。人的社会化实质上是一种社会意义上的移动,因而也需要社会认知地图来导向,以确保其成功。社会认知地图是人对社会结构的主观认识,是对人的社会化过程的程序性反映,是客观的内容和主观色调的统一。构筑积极健康的社会认知地图,不仅是必要的,而且是可能的。  相似文献   

12.
优美树猜想是一个历史悠久的猜想.1979年,Bermond猜想每一棵对虾树都是优美的.讨论了一类A(i)-系列对虾树的优美性和奇优美性,并给出相应结论.  相似文献   

13.
Infectious disease has joined habitat loss and hunting as threats to the survival of the remaining wild populations of great apes. Nevertheless, relatively little is known about the causative agents. We investigated an unusually high number of sudden deaths observed over nine months in three communities of wild chimpanzees (Pan troglodytes verus) in the Ta? National Park, Ivory Coast. Here we report combined pathological, cytological and molecular investigations that identified Bacillus anthracis as the cause of death for at least six individuals. We show that anthrax can be found in wild non-human primates living in a tropical rainforest, a habitat not previously known to harbour B. anthracis. Anthrax is an acute disease that infects ruminants, but other mammals, including humans, can be infected through contacting or inhaling high doses of spores or by consuming meat from infected animals. Respiratory and gastrointestinal anthrax are characterized by rapid onset, fever, septicaemia and a high fatality rate without early antibiotic treatment. Our results suggest that epidemic diseases represent substantial threats to wild ape populations, and through bushmeat consumption also pose a hazard to human health.  相似文献   

14.
 随着人类城市化进程的加剧,引起了一系列的生态环境问题,导致人与自然的矛盾加剧,特别是疫灾的出现,极大地危害人体健康、破坏城市秩序、危及社会的稳定和可持续性、造成社会经济的重大损失。结合史上重大疫灾的分析,从生态规划的视角,寻找疫灾产生的根本原因及生态规划工作中存在的问题,重点研究人与生物(动物、植物、微生物)之间的相互关系,并提出完善健康城市建设及生态规划的理念及策略。建议在今后的生态规划中,建立、完善人与生物和谐共生的人居环境,加强生物规划,从以人为本,打造人与自然的生命健康共同体。  相似文献   

15.
Kin recognition helps cooperation to evolve in many animals, but it is uncertain whether microorganisms can also use it to focus altruistic behaviour on relatives. Here we show that the social amoeba Dictyostelium purpureum prefers to form groups with its own kin in situations where some individuals die to assist others. By directing altruism towards kin, D. purpureum should generally avoid the costs of chimaerism experienced by the related D. discoideum.  相似文献   

16.
内蒙古草地退化原因分析及其恢复治理的科技支撑   总被引:10,自引:0,他引:10  
描述了内蒙古草原的自然环境特征和生态环境退化现状。从系统物流平衡、环境气候变化 ,以及人类活动对草地生态系统的影响等方面探讨了该地区生态环境劣变的原因。分析结果表明 ,放牧畜牧业是该地区的主要土地利用形式 ,家畜是生态系统中植被的主要控制者 ,系统内物流的出入失调和季节性的草—畜供求失衡是引起草地生态系统迅速退化的主要因素。而其它因素(如气候变化、垦荒、挖药材等 )对系统的劣变起了推波助澜的作用。作者指出 ,健全科研和推广体系 ,加大科学技术普及力度 ,增加向系统内的物质投入 ,调整四季放牧的自然畜牧业生产方式 ,积极引种入牧 ,缓解草地春季敏感期放牧压力等 ,是治理和维护该地区草地生态系统健康的有效措施。  相似文献   

17.
本文对棒状杆菌(Corynebacterium spp.)感染引起的过度角化症的流行病学特点、临床症状、诊断方法和防控净化措施的研究进展进行综述.结合啮齿类实验动物饲养管理特点,推荐有效的动物设施灭菌净化方法以及科学的预防控制措施.当动物设施被诊断出牛棒状杆菌(Corynebacterium bovis)感染,建议对饲...  相似文献   

18.
The effects of individual removal by zoo managers on behavior and fecal glucocorticoid changes in snub-nosed monkeys(Rhinopithecus roxellana) were investigated at Beijing Zoo.The results showed that the effect of the removal of three subordinate individuals(DD,male,4 years;XZZ,male,3 years and LL,female,3 years) from a group varied across the remaining group members that may be related to individual’s social status,gender and age.The dominant male was impacted less than subordinate individuals in both the frequency and time duration for the four main behavioral categories.The frequency of stereotypic behavior significantly decreased in the dominant female after the removal of three animals(Z= 2.862,P=0.003).Fluctuations were found in both the behavioral frequency and time duration in other remaining individuals.These findings suggest that small,socially stable groups were somewhat resilient to changes in member composition.Moreover,the cortisol level did not change significantly in the remaining members.An alternative method of hormone assay using fecal samples for vulnerable animals was presented,and that may be useful for monitoring wild golden monkeys and other endangered species of animal.  相似文献   

19.
标准化是实验动物的根本属性,质量标准是实验动物质量控制体系中的重要组成部分,实验动物微生物和寄生虫控制水平是实验动物分级的根本依据。 本文介绍了黑龙江省地方标准《实验动物牛微生物学等级及监测》 和《实验动物牛寄生虫学等级及监测》的编制背景、实验牛等级设定、检测项目的选择、检测方法、预期社会效益等主要内容。 本标准的制定可为黑龙江省农业实验动物新资源提供标准及技术保障、为公共卫生和生物安全提供重要的基础条件、为重大动物疫病研究提供高质量实验动物以及为生物制品的研发、生产及检定提供标准化实验动物,进而推动我省及全国畜牧行业技术进步及畜牧业的健康发展。  相似文献   

20.
根据染病者在不同阶段具有不同的传染力以及不同阶段的染病者可以转化的特性,建立了一类带有阶段结构的传染病传播模型。借助再生矩阵求得了所建模型的基本再生数,并应用极限系统理论证得:当基本再生数不超过1时,模型仅存在全局稳定的无病平衡点;当基本再生数大于1时,无病平衡点不稳定,而且存在渐近稳定的地方病平衡点,当不考虑因病死亡率时,地方病平衡点是全局渐近稳定的。  相似文献   

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