Survival of extrapair and within-pair young in tree swallows

In monogamous species, it is generally accepted that males seekextrapair matings to increase their reproductive success withoutadditional parental investment; however, the benefits of extrapairmatings to females are much less clear. One possibility isthat females obtain genes for enhanced offspring viabilityfrom the extrapair sires. If this is the case, then the increasedviability of extrapair young may be evident throughout the periodof embryonic development as well as later in life. Tree swallows(Tachycineta bicolor) have one of the highest known levelsof extrapair mating in birds, and females have substantialcontrol over the paternity of their offspring. We used moleculartechniques to determine the parentage of nestlings and unhatchedembryos to examine the possibility that female tree swallowsgain viability benefits for their extrapair offspring. Althoughboth extrapair paternity and mortality of embryos and nestlingswere high (89% and 54% of broods respectively), we found nodifference in the viability of within-pair and extrapair youngprior to fledging. In addition, extrapair young were not morelikely to be male. There was no bias in the sex of young atfledging, but unhatched embryos were more likely to be male.Our results do not support the idea that female tree swallowsengage in extrapair mating to increase offspring viability,at least early in life.     

国际转基因标识制度变动趋势分析及对我国的启示

转基因标识与消费者知情权和选择权密切相关,因而成为最受关注的转基因政策之一。从1997年第一个转基因标识制度诞生开始,全球已有70多个国家和地区开展了各具特色的转基因产品标识管理。2015年以来,受转基因产业发展政策、公众接受程度、农产品贸易需求、国家政治立场等多重因素的影响和作用,美国、韩国、俄罗斯、乌克兰和日本等国家相继着手调整转基因标识政策或改变实施细则,呈现出强制标识呼声高、标识范围扩大、标注方式更加明确、阴性标识更规范等特点。通过分析国际转基因标识制度及变动趋势,提出了我国转基因标识在扩大标识范围、设立标识豁免阈值和规范阴性标识等方面的管理建议。     

The evolution of siderophore production as a competitive trait

Microbes have the potential to be highly cooperative organisms. The archetype of microbial cooperation is often considered to be the secretion of siderophores, molecules scavenging iron, where cooperation is threatened by “cheater” genotypes that use siderophores without making them. Here, we show that this view neglects a key piece of biology: siderophores are imported by specific receptors that constrain their use by competing strains. We study the effect of this specificity in an ecoevolutionary model, in which we vary siderophore sharing among strains, and compare fully shared siderophores with private siderophores. We show that privatizing siderophores fundamentally alters their evolution. Rather than a canonical cooperative good, siderophores become a competitive trait used to pillage iron from other strains. We also study the physiological regulation of siderophores using in silico long‐term evolution. Although shared siderophores evolve to be downregulated in the presence of a competitor, as expected for a cooperative trait, privatized siderophores evolve to be upregulated. We evaluate these predictions using published experimental work, which suggests that some siderophores are upregulated in response to competition akin to competitive traits like antibiotics. Although siderophores can act as a cooperative good for single genotypes, we argue that their role in competition is fundamental to understanding their biology.     

MHC-mediated mate choice increases parasite resistance in salmon

Natural (parasite-driven) and sexual selection are thought to maintain high polymorphism in the genes of the major histocompatibility complex (MHC), but support for a link between mate choice, MHC variation and increased parasite resistance is circumstantial. We compared MHC diversity and Anisakis loads among anadromous Atlantic salmon (Salmo salar L.) returning to four rivers to spawn, which had originated from natural spawning (parents allowed to mate freely) or artificial crosses (parents deprived from the potential benefits of mate choice). We found that the offspring of artificially bred salmon had higher parasite loads and were almost four times more likely to be infected than free-mating salmon, despite having similar levels of MHC diversity. Moreover, the offspring of wild salmon were more MHC dissimilar than the offspring of artificially crossed salmon, and uninfected fish were more dissimilar for MHC than infected fish. Thus, our results suggest a link between disassortative mating and offspring benefits and indicate that MHC-mediated mate choice and natural (parasite-driven) selection act in combination to maintain MHC diversity, and hence fitness. Therefore, artificial breeding programmes that negate the potential genetic benefits of mate choice may result in inherently inferior offspring, regardless of population size, rearing conditions or genetic diversity.     

Studies on the mode of action of calciferol: Biological activity of 1α,24R,25-trihydroxyvitamin D3 in the chick

The biological activity of 1α,24R,25-trihydroxyvitamin D₃ [1α,24R,25(OH)₃D₃] was elevated in comparison to the hormonally active form of vitamin D₃, 1α,25-dihydroxyvitamin D₃ [1α,25(OH)₂D₃], in the rachitic chick in terms of its ability to (a) stimulate intestinal calcium absorption, (b) mobilize bone calcium, (c) induce intestinal calcium binding protein, (d) modulate the level of enzyme activity of the renal 25-OH-D₃-1-hydroxylase system, and (e) interact with the intestinal cystosol-chromatin receptor system for the 1α,25(OH)₂D₃ receptor system. In each of these assays, the relative ratio of activity of 1α,24R,25(OH)₃D₃ to 1α,25(OH)₂D₃was (a) 25–50, (b) ca. 20, (c) 10, (d) 50, and (e) 36%, respectively.     

GOOD GENES AND DIRECT SELECTION IN THE EVOLUTION OF MATING PREFERENCES

A model is used to study quantitatively the impact of a good genes process and direct natural selection on the evolution of a mating preference. The expression of a male display trait is proportional to genetic quality, which is determined by the number of deleterious mutations a male carries throughout his genome. Genetic variances and covariances, including the covariance between the preference and male trait that drives the good genes process, are allowed to evolve under an infinitesimal model. Results suggest that the good genes process generates only weak indirect selection on preferences, with an effective selection intensity of a few percent or less. If preferences are subject to direct natural selection of the intensity observed for other characters, the good genes process alone is not expected to exaggerate the male trait by more than a few phenotypic standard deviations, contrary to what is observed in highly sexually selected species. Good genes can, however, cause substantial exaggeration if preference genes are nearly selectively neutral. Alternatively, direct selection on preference genes, acting on mating behavior itself or on the genes' pleiotropic effects, can cause mating preferences and male display traits to be exaggerated by any degree. Direct selection of preference genes may therefore play an important role in species that show extreme sexual selection.     

Dream and blog content analysis of a long term diary of a video game player with obsessive compulsive disorder.

A case study of a young man who is an avid video game player and designer is the focus of this paper. His online Website offers over 800 dreams, of which over half were content analyzed using the Hall and Van de Castle system. Also available were daily blogs. Thus, several research questions could be addressed. Did the diary evidence consistency across time? Did the dreams evidence incorporation of activities discussed in the daily blogs from the day before the dream? Did this one individual's dream diary echo former research into the dreams of video game players? A final question was addressed because of the diagnosis of the diarist as having Obsessive Compulsive Disorder (OCD). Did the dreams of this young man echo previous research into dreams of OCD sufferers? The findings were that the diary was consistent across time and there was incorporation of some elements of the daily blog into subsequent dreams. Some aspects of his dreams echoed previous video game players' dream findings, like more dead and imaginary characters. Finally, the OCD analysis only partly replicated the previous research into the dreams of those with OCD. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Exploring lake user and manager knowledge of aquatic invasive species in New Hampshire freshwater lake systems,USA

Aquatic invasive species (AIS) threaten freshwater ecosystem structure and function worldwide. Such changes trigger a variety of negative impacts on lake recreation and the economics of individuals, towns, and states. Recent studies suggest environmental educational efforts have been an effective tool in raising public awareness of AIS; however, we lack a more general understanding of how public versus manager knowledge of invasive species and their threats to freshwater ecosystems and human livelihoods. To fill this gap, we surveyed New Hampshire lake users and interviewed lake managers to 1) identify the key issues surrounding AIS management; and 2) assess public awareness of the AIS problem and their management at three lakes in New Hampshire. Our interviews with managers suggest that educational outreach is a key mechanism for combatting the AIS problem. The general public surveys further differentiated respondents into two groups that differed demography and in AIS knowledge and concern. Together, our results indicate that AIS management efforts depend heavily on funding, regional cooperation, and commitment of individual managers and lake-users. Blanket outreach campaigns have been effective in expanding the knowledge reach of AIS, but they remain too general to engage the public in AIS spread prevention and eradication. Instead, integrating practices of rapid response and appeals to responsibility norms among lake users is paramount for combatting the AIS problem in this region.     

The influence of male age on within‐pair and extra‐pair paternity in passerines

Although male age has often been found to predict success in gaining extra‐pair paternity, it is unclear whether this gain is associated with an individual’s success in avoiding cuckoldry. We examined the relationship between male age and both within‐ and extra‐pair paternity in passerines using a meta‐analytical approach. There was a positive correlation between male age and success in extra‐pair paternity but little evidence for an association between male age and within‐pair paternity. In addition, effect sizes for male within‐pair paternity and male extra‐pair paternity were not significantly correlated. Thus, factors that predict success in obtaining extra‐pair paternity, such as male age, may not necessarily predict success in avoiding cuckoldry.     

Application of good laboratory practice (GLP) to culture collections of microbial and cell cultures

Although the principles and the necessity for good laboratory practice (GLP) guidelines to confirm the credibility, integrity, and quality of non-clinical laboratory studies have been known for more than a decade, culture collection activities are not subject to them. Because of recent advances in biotechnology, culture collections face increased demands not only for quality cultures but also current information. When applied in culture collections, GLP guidelines prove to be an excellent management tool as well as a cost-effective system of providing authentic and reliable microbial and cell cultures and associated data.