Hunting G-quadruplexes

Whilst DNA spends much of its time in the double-stranded form, frequently in storage, wrapped around histones and packaged as chromatin, it can also form other complex structures, which may play a role in natural regulation and gene control. These alternative structures therefore also present an interesting novel series of targets for artificial intervention, and so may lead to novel therapeutics. In this review, I describe the current understanding of how genomic and bioinformatics studies may be used to understand the roles that one such structure, the four-stranded guanine-rich G-quadruplex, may play in the genome, and outline how these may be considered as targets for intervention. I will also describe recent work looking at RNA G-quadruplexes, and the biological roles they may play.     

Aboriginal Australian Net Hunting

Game capture in nets was a common practice in many parts of Aboriginal Australia. The nets used for this purpose varied considerably in size and form, were employed in a variety of environ mental settings and were applied to the procurement of a major proportion of the terrestrial, aquatic and avian prey species available on the continent. Because net hunting was so prevalent among hunter-gatherers around the world, Aboriginal net hunting can be regarded as an Australian manifestation of a worldwide phenomenon.     

Drivers of Bushmeat Hunting and Perceptions of Zoonoses in Nigerian Hunting Communities

Bushmeat hunting threatens biodiversity and increases the risk of zoonotic pathogen transmission. Nevertheless, limited information exists on patterns of contact with wildlife in communities that practice bushmeat hunting, especially with respect to social drivers of hunting behavior. We used interview responses from hunters and non-hunters in rural hunting communities in Nigeria to: 1) quantify contact rates with wildlife, 2) identify specific hunting behaviors that increase frequency of contact, 3) identify socioeconomic factors that predispose individuals to hunt, and 4) measure perceptions of risk. Participants engaged in a variety of behaviors that increased contact with wild animals, including: butchering to sell (37%), being injured (14%), using body parts for traditional medicine (19%), collecting carcasses found in forests and/or farms (18%), and keeping as pets (16%). Hunters came into contact with wildlife significantly more than non-hunters, even through non-hunting exposure pathways. Participants reported hunting rodents (95%), ungulates (93%), carnivores (93%), primates (87%), and bats (42%), among other prey. Reported hunting frequencies within taxonomic groups of prey were different for different hunting behaviors. Young age, lower education level, larger household size, having a father who hunts, and cultural group were all associated with becoming a hunter. Fifty-five percent of respondents were aware that they could contract diseases from wild animals, but only 26% of these individuals reported taking protective measures. Overall, hunters in this setting frequently contact a diversity of prey in risky ways, and the decision to become a hunter stems from family tradition, modified by economic necessity. Conservation and public health interventions in such settings may be most efficient when they capitalize on local knowledge and target root socio-economic and cultural drivers that lead to hunting behavior. Importantly, interventions that target consumption alone will not be sufficient; other drivers and modes of interaction with wildlife must also be considered.     

Hunting for connexin hemichannels

Connexin hemichannels (connexons) are building blocks of gap junctions but also function as free unapposed channels, which has become an active field of research. Defining functions of hemichannels and their involvement in any biological event requires ruling out possible participation of other channels that share biophysical and regulatory properties, for example pannexins, CALHM1 and P2X receptors. The lack of specific inhibitors for these channels has become an obstacle in elucidating the role of connexin hemichannels. Several experimental approaches are now available to identify hemichannels at the cell surface and to characterize their electrophysiological, permeability and regulatory properties. The use of connexin knockout/knockdown, and the development of peptides that target intracellular connexin domains and specific antibodies directed to extracellular domains have helped to dissect the role of hemichannels in endogenously expressing systems. Moreover, studies of connexin mutants in exogenous expression systems have provided convincing evidence on hemichannels in the pathogenesis of several human genetic diseases. We here present a brief overview of connexin hemichannels as functional channels and itemize a list of aspects to consider when concluding on their involvement.     

昔日狩猎家园

大兴安岭是自然杰出的造作,从古生代以来的地质运动,到第四纪形成现在的大兴安岭山脉和断裂带及河备地带。以山地地貌和台原地貌为主,河流众多,河谷宽阔,属寒漏带季风区,一年里四季分明,冬季漫长、寒冷、干燥,最低气温近零下50℃;夏季短暂,雨量充沛,最高气温在35℃左右,生长着以寒温带针叶林为主,针阔叶混变林茂密由的地带性植被,繁衍生息着獐、狍、野鹿、飞龙、榛鸡等等无数的野生动物,自古以来就是北方游猎民族的天堂。     

Big-Game Hunting Artifacts from Minnesota

Abstract

A Browns Valley type point, a Scottsbluff type point, and four Cody knives, recovered as surface finds, give evidence of the presence of the Big-Game Hunting Tradition in east-central Minnesota. These artifacts, their location, and similar finds in the Minnesota-Wisconsin area are described.     

Hunting Behavior in the Ctenizidae

The most primitive way of hunting in Mygalomorph spiders seemsto be the free roaming and catching of encountered prey Theraphosidae.The trap-door spiders Ctenizidae, Actinopodidae and Barychelidawhich are entirely sedentary, lie in wait behind the trap-doorand leap at prey that happens to pass close to the door. Somespecies spin radial silk threads outside the door which functionas stumbleor signal-lines, and some Australian species use grassblades and other litter in the same way. A further evolutionarystep leads to species which do not build a trap-door but crowntheir burrow by a funnel-shaped web. The Dipluridae finallyare real web-builders, which depend on a sheet-web to catchtheir prey. Generally they do not dig a burrow but hide in asmall retreat from which a funnel-web leads to the net. With a few exceptions Ctenizidae are entirely nocturnal. Theirrhythm of activity has been analyzed. The "Zeitgeber" is thedaylight during the last half hour before sunset. Most trapdoorspiders never leave their burrow during their whole life. Theyneed three to four years from hatching to become adults. Adultmales die during or at the end of the restricted mating-season;they take no food when adult. Females, which undergo post-adultmolts, can probably live for 15–20 years. Nemesia caementaria, like most other species, hunts during thewhole night. The mean time of activity is about Si/o hours,consisting of periods of lying in wait and periods of intermediaterests. The spiders make an average of three leaps per nightto catch a prey, but only about 10% of all bounds are successful.A hungry animal, lurking in vain, shows unmotivated leaps. The effects of light, moisture, and temperature on hunting activityare analyzed. Ctenizidae hunt during autumn, winter, and springbut interrupt their activity in summer for an estivation whichlasts usually two months. The females of some species capture the male after mating andeat him; others never attack him. This difference in behaviorlias repercussions on reproduction. Among certain species the young nymphs of the third instar refuseall food until they have made their own burrow and can huntby themselves. The young of other species stay with the motherfor one year and leave her at the fifth or sixth instar to maketheir own burrow. The young of Nemesia caementaria can remainin the burrow of the mother until they are almost adult, i.e.,for two or three years, and feed on the prey the mother hascaught. The behavior of Ctenizidae can be grouped. Some species lurkbehind the closed or almost closed trap-door. Another groupopens the trap-door and puts the pedipalpi and the two anteriorpairs of legs radially out onto the rim of the burrow, whilethe cephalothorax is hidden behind the trap-door. A third groupspins threads of silk radially about the entrance and uses themas signal-lines. A fourth group can come out and pursue theprey, then drags it to the trap-door and into the burrow. The nature of the prey depends on the bio tope. The Ctenizidaefeed almost exclusively on insects, mainly ants and beetles;in the laboratory crickets are accepted as prey. Ctenizidae have no tarsal organ. They have different types oftrichobothria, transversal and longitudinal slit-organs, andlyriform organs. With these three kinds of sense-organs, thefunctions of which are not clearly understood, the trap-doorspiders are able to perceive the approach of prey, to judgeits distance from the trap-door, and to locate it in direction.They seem to have an organ of smell, since certain groups ofinsects are repulsive to them. Sight is not used for hunting.     

微生物细胞表面呈现技术研究进展

微生物细胞表面工程是近年来发展起来的,它利用细胞表面展示技术使外源蛋白固定化于细胞表面,从而生产微生物细胞表面蛋白。微生物细胞表面工程可用于细胞催化剂、细胞吸附剂、活疫苗、生物传感器的开发等。微生物细胞表面工程具有广阔的应用前景,但是国内对这一领域的研究刚起步。在介绍细胞表面工程的基础上,对微生物细胞表面工程技术进展进行了综述,展望了对该技术的发展。