Parasitoid secretions provoke ant warfare

Insect social parasites are extreme specialists that typically use mimicry or stealth to enter ant colonies to exploit the rich, but fiercely protected, resources within their nests. Here we show how a parasitic wasp (parasitoid) contrives to reach its host, itself an endangered species of social parasite that lives inside the brood chambers of ant nests, by releasing semiochemicals to induce in-fighting between worker ants, locking the colony in combat and leaving it underprotected. Four of these chemicals are new to biology and have the potential to control pest species by inducing different agonistic behaviours in ants.     

一妻多夫制婚姻形态探析——兼谈我国藏族地区的一妻多夫制婚姻

一妻多夫制婚姻是一种古老婚姻家庭制度的遗存,即一个女子同时可与数个男子有合法婚姻关系,一妻多夫制婚姻中最重要的形式便是本家兄弟共妻。从古至今,一妻多夫制婚姻吸引了众多专家学者的关注与研究,对它有过较多的深刻论述。在我国西部地处偏远的一些少数民族地区,现今还存在一妻多夫的婚姻习俗。我国个别藏族地区的一妻多夫制婚姻形态是在特定的民族生境下形成的,除了与自然生态环境有直接关系外,与经济因素、历史制度、古代文化等也都有明显关联。     

Post-mating sexual selection increases lifetime fitness of polyandrous females in the wild

Females often mate with several males before producing offspring. Field studies of vertebrates suggest, and laboratory experiments on invertebrates confirm, that even when males provide no material benefits, polyandry can enhance offspring survival. This enhancement is widely attributed to genetic benefits that arise whenever paternity is biased towards males that sire more viable offspring. Field studies suggest that post-mating sexual selection biases fertilization towards genetically more compatible males and one controlled experiment has shown that, when females mate with close kin, polyandry reduces the relative number of inbred offspring. Another potential genetic benefit of polyandry is that it increases offspring survival because males with more competitive ejaculates sire more viable offspring. Surprisingly, however, there is no unequivocal evidence for this process. Here, by experimentally assigning mates to females, we show that polyandry greatly increases offspring survival in the Australian marsupial Antechinus stuartii. DNA profiling shows that males that gain high paternity under sperm competition sire offspring that are more viable. This beneficial effect occurs in both the laboratory and the wild. Crucially, there are no confounding non-genetic maternal effects that could arise if polyandry increases female investment in a particular reproductive event because A. stuartii is effectively semelparous. Our results therefore show that polyandry improves female lifetime fitness in nature. The threefold increase in offspring survival is not negated by a decline in maternal lifespan and is too large to be offset by an equivalent decline in the reproductive performance of surviving offspring.     

Simultaneous polyandry and heteropaternity in tiger (Panthera tigris altaica): Implications for conservation of genetic diversity in captive populations of felids

Male tigers(Panthera tigris altaica) in captivity copulate alternatively with an estrous female,suggesting a potential for heteropaternity as an effective reproductive strategy to maximize genetic diversity of offspring.We analyzed microsatellites to test and compare the genetic output of multiple male mating(simultaneous polyandry) and single male mating(monogamy) with a female in a captive population.Simultaneous polyandry resulted in heteropaternity in 66.7% observed litters.No significant differences between parental populations and between offspring populations were detected in the number of alleles(A),expected heterozygosity(H e),number of effective alleles(N e) per locus and standard individual heterozygosity(SH)(P>0.05 for all 4 indexes).Comparisons showed no significant reduction of A,H o,H e and SH from parental population to offspring population for the two mating modes(P>0.05) except for SH in polyandrous families(P=0.029).However,such reduction was equivalent to single mating families when the influence of relatedness was eliminated using effective SH(E SH)(P>0.05).These results highlight an alternative strategy for managing captive populations of tiger and other wild felids in which animals are combined at one location allowing for copulation by multiple males to encourage heteropaternity in favor of maintained genetic diversity among offspring.     

一种基于精英策略的蚁群优化QoS单播路由算法

指出传统蚁群算法在解决QoS单播路由选择问题时,受到时延和带宽的约束,为降低路由费用,容易出现陷入局部最优且收敛速度慢的现象。针对上述问题,提出一种基于精英策略的蚁群优化QoS单播路由算法,该算法利用蚁群算法原理,并引入精英策略。通过仿真模拟一个20节点的计算机网络QoS单播路由选择实例,并与传统蚁群优化（ACO）算法进行对比,仿真结果表明该算法是有效的。     

Outbred embryos rescue inbred half-siblings in mixed-paternity broods of live-bearing females

Females commonly mate with more than one male, and polyandry has been shown to increase reproductive success in many species. Insemination by multiple males shifts the arena for sexual selection from the external environment to the female reproductive tract, where sperm competition or female choice of sperm could bias fertilization against sperm from genetically inferior or genetically incompatible males. Evidence that polyandry can be a strategy for avoiding incompatibility comes from studies showing that inbreeding cost is reduced in some egg-laying species by postcopulatory mechanisms that favour fertilization by sperm from unrelated males. In viviparous (live-bearing) species, inbreeding not only reduces offspring genetic quality but might also disrupt feto-maternal interactions that are crucial for normal embryonic development. Here we show that polyandry in viviparous pseudoscorpions reduces inbreeding cost not through paternity-biasing mechanisms favouring outbred offspring, but rather because outbred embryos exert a rescuing effect on inbred half-siblings in mixed-paternity broods. The benefits of polyandry may thus be more complex for live-bearing females than for females that lay eggs.     

多车次同时送取货物车辆路径问题的量子蚁群算法

研究了配送车辆载重量和工作时间有限,考虑货物装卸时间的多车次同时送货和取货的车辆路径问题(multi-trip vehicle routing problem with simultaneous deliveries and pickups,MTVRPSDP),建立了以配送车辆启动成本和车辆行驶成本之和最小为目标的线性整数规划模型.将量子计算和基本蚁群算法相结合提出了求解MTVRPSDP的量子蚁群算法,该算法应用量子比特启发式因子改进了人工蚂蚁的转移概率,从而提高了算法的全局搜索能力和稳定性,有效改进了算法陷入局部最优的缺陷.算例分析表明:MTVRPSDP的线性整数规划模型在实际应用中是可行和有效的,而且相比于基本蚁群算法和文献中所给其他算法的计算结果,利用量子蚁群算法和MTVRPSDP的线性整数规划模型能够得到较好的满意解,安排的车辆配送路线更加经济合理.     

蜻蜓捕食婚飞红火蚁的初步观察

报道了黄蜻(Pantala flavescens Fabricius)对婚飞红火蚁的捕食作用。蜻蜓聚集在婚飞红火蚁的蚁巢上方捕食婚飞红火蚁,平均17只?巢.次,最多40只蜻蜓同时出现于一个婚飞的蚁巢上方。距离地面5 m以下,蜻蜓对婚飞红火蚁的捕食率平均为85.66%,捕食行为主要发生在距离地面3 m以下。捕到婚飞蚁后,蜻蜓立即取食其腹部,丢弃其余部分。蜻蜓这种捕食行为与红火蚁的婚飞同时出现在降雨天气之后的1~2 d内。     

蜻蜒捕食婚飞红火蚁的初步观察

报道了黄蜻（Pantala flavescens Fabricius）对婚飞红火蚁的捕食作用。蜻蜓聚集在婚飞红火蚁的蚁巢上方捕食婚飞红火蚁，平均17只／巢．次，最多40只蜻蜓同时出现于一个婚飞的蚁巢上方。距离地面5m以下，蜻蜓对婚飞红火蚁的捕食率平均为85．66％，捕食行为主要发生在距离地面3m以下。捕到婚飞蚁后，蜻蜓立即取食其腹部，丢弃其余部分。蜻蜒这种捕食行为与红火蚁的婚飞同时出现在降雨天气之后的1～2d内。     

雄激素与鼠类的社会行为

雄激素引起的社会行为包括杀婴行为、攻击行为、交配行为和社会识别行为等 ,雄激素首先引起脑结构的性差 ,是雌雄个体社会行为发生差异的基础 .雄激素引起的杀婴行为目前还有争议 ,多数学者认为还与孕酮有关 ;雄激素引起的攻击行为还受年龄、生殖状态 (泌乳时期 )、婚配制度、父本扶养还是母本扶养等各种因素的影响 ;雄激素引起的交配行为、社会识别行为还与化学感觉系统有关 ,社会识别主要由抗利尿激素依赖雄激素而产生 .     

基于群体智能的蚁群算法研究

群体智能是指任何启发于群居性昆虫群体和其它动物群体的集体行为而设计的算法和分布式问题解决装置,群体智能现正在成为人工智能领域和相关领域的一个研究热点;该文首先介绍了群体智能中的两个重要算法:蚁群算法和粒子群算法的基本思想,然后重点探讨了蚁群优化算法,对基本蚁群算法和改进的蚁群算法进行了深入的分析和评述。     

Audience drives male songbird response to partner's voice

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.     

密度对蚁群自组织聚集的影响

在生物及人类社会中,自组织聚集是十分普遍而且重要的集群行为,也是近年来蓬勃发展的交叉领域.为了定量地深入研究自组织聚集的宏观规律,我们用实验方法研究了草地铺道蚁的自组织聚集与其密度之间的关系,采用层次社会熵和样方法的统计手段测量蚂蚁群体的聚集度,以定量度量其自组织聚集程度.精确控制的实验以及基于实验数据的统计分析表明,蚂蚁群体在低密度下呈现近随机分布状态,高密度下稳定于显著的聚集状态,即蚂蚁聚集的程度是密度依赖的.实验给出的佐证在后续探究蚂蚁聚集的微观机制研究中将起到至关重要的作用,能够引起聚集行为涌现的简单机制是与密度密切相关的.     

A socially enforced signal of quality in a paper wasp

Organisms use signals of quality to communicate information about aspects of their relative phenotypic and genetic constitution. Badges of status are a subset of signals of quality that reveal information about an individual's size and dominance. In general, signals of quality require high and differential costs to remain honest (that is, prevent low-quality cheaters from exploiting any fitness benefits associated with communicating high quality). The theoretically required costs for badges of status remain controversial because the development (or 'production') of such signals often seems to be relatively cost-free. One important hypothesis is that such signals impose social (or 'maintenance') costs incurred through repeated agonistic interactions with other individuals. However, convincing empirical evidence for social costs remains elusive. Here we report social costs in a previously undescribed badge of status: the highly variable black facial patterns of female paper wasps, Polistes dominulus. Facial patterns strongly predict body size and social dominance. Moreover, in staged contests between pairs of unfamiliar wasps, subordinate wasps with experimentally altered facial features ('cheaters') received considerably more aggression from the dominant than did sham controls, indicating that facial patterns are signals and that dishonest signalling imposes social costs.     

基于聚类蚁群算法的物流最优路径

在物流网络系统中,物品的配送是重要的一环,一个科学的物流配送路径,不仅能在一定程度上降低物品的配送时间,而且能有效的降低运输资源的占用,这极大的降低了物流企业的运营成本。针对物流配送路径的最优解问题,有大量的学者进行了相关研究,主要有遗传算法、蚁群算法、生物地理学算法等,其中以蚁群算法应用最为广泛;但这些算法都只是在物流运输的路径上进行优化,并没有考虑空载率以及客户对送货时间的要求。为了克服此缺点,本文在蚁群算法的基础上加入空载率和时间窗的要素,对传统的蚁群算法进行优化。实验结果表明,与传统的蚁群算法相比,该算法可以有效的节约物流运输资源。     

Polyandrous females avoid costs of inbreeding.

Why do females typically mate with more than one male? Female mating patterns have broad implications for sexual selection, speciation and conflicts of interest between the sexes, and yet they are poorly understood. Matings inevitably have costs, and for females, the benefits of taking more than one mate are rarely obvious. One possible explanation is that females gain benefits because they can avoid using sperm from genetically incompatible males, or invest less in the offspring of such males. It has been shown that mating with more than one male can increase offspring viability, but we present the first clear demonstration that this occurs because females with several mates avoid the negative effects of genetic incompatibility. We show that in crickets, the eggs of females that mate only with siblings have decreased hatching success. However, if females mate with both a sibling and a non-sibling they avoid altogether the low egg viability associated with sibling matings. If similar effects occur in other species, inbreeding avoidance may be important in understanding the prevalence of multiple mating.     

珠多村藏族农民家庭调查

文章对珠多村的所有单偶和多偶家庭进行了系统的调查,分析了单偶和多偶家庭形成的条件及他们的相关关系。指出,珠多村对一妻多夫家庭普遍持称赞的态度,但也有部分多兄弟家庭在村内分家,另外娶妻建立新家,还有少量的一妻多夫家庭婚后分家的情况。表明社会称赞的婚姻形式与实际的婚姻形式之间有一定的差距。这种差距,就其经济原因而言,主要是土地、房屋等家庭财产和劳动力,对违反习俗者并没有很严格的约束力,从而给多兄弟家庭中的个人是选择一妻多夫还是一夫一妻婚留下了较大的空间。     

面向用户的通用云计算平台负载均衡机制

面向用户的通用云计算平台负载均衡机制在探寻云计算平台的成本和效用的基础上,由用户根据任务粒度从质量、成本定制云及云联盟资源三方面权重。由云均衡构件发出蚂蚁群搜索云内及云间计算资源。蚁群采用优化算法搜索资源并将信息发回蚁巢,并监视各个计算资源动态变化及时均衡负载,以降低云运营商成本和用户费用,提高云及云联盟的成本效用。将该负载均衡机制应用在自主研发的云计算平台上,实验结果验证了该负载均衡机制的可行性和优越性。     

实验平台装置边缘影响和蚁群聚集程度研究

为深入研究自组织聚集的微观机制, 采用日本弓背蚁作实验材料, 在二维正方形平面和二维圆形平面实验台上进行蚁群实验, 通过高速摄像机视频跟踪并进行定量统计分析. 实验结果表明, 实验装置边缘对蚂蚁有“吸引”作用, 随着群体规模增加, 装置边缘对蚁群吸引减弱. 通过研究蚂蚁速度, 发现因为装置边缘的吸引, 蚂蚁在边界和非边界运动状态不同. 在边界, 蚂蚁主要状态是“停止”和“低速运动”; 在非边界, 蚂蚁主要状态是“低速运动”. 本文首次提出用层次社会熵定量测量蚁群聚集程度, 发现其随着蚁群群体规模增加呈现先上升后下降趋势, 表明蚁群聚集程度随着蚁群群体规模增加先下降后上升.      

改进型蚁群算法在Job Shop问题中的应用

应用改进型蚁群算法解决车间作业调度问题。在原有标准蚁群算法的基础上采用了新的状态转移规则,讨论了各种不同的轨迹更新规则对仿真结果的影响,并通过统计数据验证了改进型蚁群算法优于标准的蚁群优化算法。由于算法中的参数对算法的求解效率和求解结果都有一定的影响,所以对此也进行了初步的研究,得到了运行较好的参数取值范围。