Is dauer pheromone of<Emphasis Type="Italic"> Caenorhabditis elegans</Emphasis> really a pheromone?

Animals respond to signals and cues in their environment. The difference between a signal (e.g. a pheromone) and a cue (e.g. a waste product) is that the information content of a signal is subject to natural selection, whereas that of a cue is not. The model free-living nematode Caenorhabditis elegans forms an alternative developmental morph (the dauer larva) in response to a so-called dauer pheromone, produced by all worms. We suggest that the production of dauer pheromone has no fitness advantage for an individual worm and therefore we propose that dauer pheromone is not a signal, but a cue. Thus, it should not be called a pheromone.     

Does a parthenogenesis-inducing <Emphasis Type="Italic">Wolbachia</Emphasis> induce vestigial cytoplasmic incompatibility?

Wolbachia is a maternally inherited bacterium that manipulates the reproduction of its host. Recent studies have shown that male-killing strains can induce cytoplasmic incompatibility (CI) when introgressed into a resistant host. Phylogenetic studies suggest that transitions between CI and other Wolbachia phenotypes have also occurred frequently, raising the possibility that latent CI may be widespread among Wolbachia. Here, we investigate whether a parthenogenesis-inducing Wolbachia strain can also induce CI. Parthenogenetic females of the parasitoid wasp Asobara japonica regularly produce a small number of males that may be either infected or not. Uninfected males were further obtained through removal of the Wolbachia using antibiotics and from a naturally uninfected strain. Uninfected females that had mated with infected males produced a slightly, but significantly more male-biased sex ratio than uninfected females that had mated with uninfected males. This effect was strongest in females that mated with males that had a relatively high Wolbachia titer. Quantitative PCR indicated that infected males did not show higher ratios of nuclear versus mitochondrial DNA content. Wolbachia therefore does not cause diploidization of cells in infected males. While these results are consistent with CI, other alternatives such as production of abnormal sperm by infected males cannot be completely ruled out. Overall, the effect was very small (9%), suggesting that if CI is involved it may have degenerated through the accumulation of mutations.     

Triterpene saponin hemi-biosynthesis of a leaf beetle’s (<Emphasis Type="Italic">Platyphora kollari</Emphasis>) defensive secretion

The adults of the leaf beetle Platyphora kollari (Chrysomelidae) are able to metabolise the oleanane triterpene β-amyrin (1) into the glycoside 3-O-β-d-glucopyranosyl-(1→4)-β-d-glucuronopyranosyl-hederagenin (2) that is stored in their defensive glands. The aim of this study was to test the hypothesis that oleanolic acid (3) is an intermediate in the conversion of 1 into 2 and to check whether the sequestration of pentacyclic triterpenes is selective in favour of β-amyrin (1). To this end, adults of P. kollari were fed with Ipomoea batatas leaf disks painted with a solution of [2,2,3-²H₃]oleanolic acid or [2,2,3-²H₃]α-amyrin and the secretion of their defensive glands analysed by HPLC–ESIMS. The data presented in this work indicated that the first step of the transformation of β-amyrin (1) into the sequestered glycoside 2 is its oxidation into oleanolic acid (3) and that this conversion is selective but not specific in favour of β-amyrin (1).     

Olfaction in a viscous environment: the “color” of sexual smells in <Emphasis Type="Italic">Temora longicornis</Emphasis>

We investigate chemical aspects of mating in the marine copepod Temora longicornis (Copepoda, Calanoidea). Our emphasis is the female pheromone signaling in form of well-defined trails for males to follow, observed in Doall et al. (Phil Trans R Soc Lond B 353:681–689, 1998). The viscous environment and the properties of the odorants play important roles as the spread of the pheromone trail limits the time during which it is useful for tracing. A key observation from our earlier work is the ability of a searching male to detect the direction of the female and to correct its swimming direction if necessary. We propose a simple mathematical model for the spread of a pheromone from a moving source and carry out numerical simulations of two possible detection mechanisms. We find that a searching agent that is capable to detect a ratio outperforms a searcher that depends on the gradient of a single compound. This suggests that copepod sex pheromones consist of blends of chemical compounds, and that a ratio detection mechanism similar to that in airborne insects is at work.     

近50 a塔里木河流域“四源”农业用水与干流生态系统结构变化关系研究

塔里木河源流区农业用水量直接影响下放至干流的水量,从而间接影响干流区生态系统结构的稳定性。为此,研究基于农业水足迹反映农业用水变化情况,进而分析塔里木河流域“四源”农业用水与干流生态系统结构变化的关系,为后续维护干流生态系统结构稳定性决策提供科学参考依据。结果表明：1960年代—1990年塔里木河“四源”农用地总量变化不大,阿克苏河流域新开垦量与叶尔羌河流域减少量相当,农业水足迹同时呈缓慢小幅增长,干流生态系统结构变化以自然绿洲生态系统缩小和荒漠生态系统扩张为主;以2000年为分界点,2000年之前“四源”农用地和农业水足迹显著增加,导致干流生态系统中自然水域生态系统、自然绿洲生态系统和荒漠生态系统皆有不同程度的萎缩,“四源”农业用水消耗是干流生态系统恶化的直接原因;2000年之后在生态治理工程的影响下,虽然“四源”农用地和总农业水足迹在持续增加,但是节水工程年均节约近27.22×10⁸ m³,保证了下游生态系统的需水量,使其得到一定恢复。     

Why do <Emphasis Type="Italic">Manduca sexta</Emphasis> feed from white flowers? Innate and learnt colour preferences in a hawkmoth

Flower colour is an important signal used by flowering plants to attract pollinators. Many anthophilous insects have an innate colour preference that is displayed during their first foraging bouts and which could help them locate their first nectar reward. Nevertheless, learning capabilities allow insects to switch their colour preferences with experience and thus, to track variation in floral nectar availability. Manduca sexta, a crepuscular hawkmoth widely studied as a model system for sensory physiology and behaviour, visits mostly white, night-blooming flowers lacking UV reflectance throughout its range in the Americas. Nevertheless, the spectral sensitivity of the feeding behaviour of naïve moths shows a narrow peak around 450 nm wavelengths, suggesting an innate preference for the colour blue. Under more natural conditions (i.e. broader wavelength reflectance) than in previous studies, we used dual choice experiments with blue- and white-coloured feeders to investigate the innate preference of naïve moths and trained different groups to each colour to evaluate their learning capabilities. We confirmed the innate preference of M. sexta for blue and found that these moths were able to switch colour preferences after training experience. These results unequivocally demonstrate that M. sexta moths innately prefer blue when presented against white flower models and offer novel experimental evidence supporting the hypothesis that learning capabilities could be involved in their foraging preferences, including their widely observed attraction to white flowers in nature.     

海伦&#183;伊丽莎白&#183;克拉克

海伦&#183;伊丽莎白&#183;克拉克（Helen Elizabeth Clark）,1950年2月26日出生于新西兰哈密尔顿市。她早年就读于提帕胡小学、奥克兰爱普松女子语言学校,后在奥克兰大学攻读文学学士和文学硕士学位,于1976年获得大学格兰特委员会奖学金,随后出国留学,之后在奥克兰大学政治系执教8年。     

Histological,chemical, and morphological reexamination of the “heart” of a small Late Cretaceous <Emphasis Type="BoldItalic">Thescelosaurus</Emphasis>

A three-dimensional, iron-cemented structure found in the anterior thoracic cavity of articulated Thescelosaurus skeletal remains was hypothesized to be the fossilized remains of the animal’s four-chambered heart. This was important because the finding could be interpreted to support a hypothesis that non-avian dinosaurs were endothermic. Mammals and birds, the only extant organisms with four-chambered hearts and single aortae, are endotherms. The hypothesis that this Thescelosaurus has a preserved heart was controversial, and therefore, we reexamined it using higher-resolution computed tomography, paleohistological examination, X-ray diffraction analysis, X-ray photoelectron spectroscopy, and scanning electron microscopy. This suite of analyses allows for detailed morphological and chemical examination beyond what was provided in the original work. Neither the more detailed examination of the gross morphology and orientation of the thoracic “heart” nor the microstructural studies supported the hypothesis that the structure was a heart. The more advanced computed tomography showed the same three areas of low density as the earlier studies with no evidence of additional low-density areas as might be expected from examinations of an ex situ ostrich heart. Microstructural examination of a fragment taken from the “heart” was consistent with cemented sand grains, and no chemical signal consistent with a biological origin was detected. However, small patches of cell-like microstructures were preserved in the sandstone matrix of the thoracic structure. A possible biological origin for these microstructures is the focus of ongoing investigation.     

Within-population variation in ejaculate characteristics in a prolonged breeder,Peron’s tree frog, <Emphasis Type="Italic">Litoria peronii</Emphasis>

Sperm number is often a good predictor of success in sperm competition; however, it has become increasingly clear that, for some species, variation in probability of paternity cannot be explained by sperm number alone. Intraspecific variation in ejaculate characteristics, such as the number of viable sperm and sperm longevity, may play an equally important role in determining fertilization success. Here, we assess variation among ejaculates in three factors that may contribute to fertilization success (number of sperm per ejaculate, viability, and longevity), in a population of Peron’s tree frog (Litoria peronii). We detected large variation among males in the number of sperm per ejaculate and the proportion of viable sperm within ejaculates, which could not be explained by variation in either male size or body condition. However, the proportion of viable sperm released by males increased over the season. Finally, we assessed sperm longevity (proportion viable sperm determined using a dual-fluorochrome vital dye) at two different temperatures. At 23°C, on average, 75% of sperm remained viable after 2 h, but there were significant differences amongst males with the percentage of viable sperm ranging from 43% to 95%. For sperm incubated at 4°C, ejaculates varied fivefold in sperm longevity with some males having 50% viable sperm after 5 days. Our data suggest that ejaculate characteristics (sperm number, viability, and longevity) vary widely in Peron’s tree frog and may therefore play an important role in determining siring success both in the presence and absence of sperm competition. We discuss the results in relation to selection on ejaculate traits via natural and sexual selection in this and other amphibians.     

胡利娅&#183;卡拉维亚斯&#183;利略

胡利娅&#183;卡拉维亚斯&#183;利略。墨西哥前环境、资源和渔业部部长,墨西哥国立自治大学生物学教授。卡拉维亚斯教授1954年出生于墨西哥城,在墨西哥国立自治大学获得学位后留校教授环境科学并从事热带雨林保护、自然资源管理和环境保护方面的研究。     

Prospective thinking in a mustelid? <Emphasis Type="Italic">Eira barbara</Emphasis> (Carnivora) cache unripe fruits to consume them once ripened

The ability of nonhuman animals to project individual actions into the future is a hotly debated topic. We describe the caching behaviour of tayras (Eira barbara) based on direct observations in the field, pictures from camera traps and radio telemetry, providing evidence that these mustelids pick and cache unripe fruit for future consumption. This is the first reported case of harvesting of unripe fruits by a nonhuman animal. Ripe fruits are readily taken by a variety of animals, and tayras might benefit by securing a food source before strong competition takes place. Unripe climacteric fruits need to be harvested when mature to ensure that they continue their ripening process, and tayras accurately choose mature stages of these fruits for caching. Tayras cache both native (sapote) and non-native (plantain) fruits that differ in morphology and developmental timeframes, showing sophisticated cognitive ability that might involve highly developed learning abilities and/or prospective thinking.     

The attractiveness fragment—AFLP analysis of local adaptation and sexual selection in a caeliferan grasshopper, <Emphasis Type="Italic">Chorthippus biguttulus</Emphasis>

Genetic variability among males is a necessary precondition for the evolution of female choice based on indirect genetic benefits. In addition to mutations and host–parasite cycles, migration of locally adapted individuals offers an explanation for the maintenance of genetic variability. In a previous study, conducting a reciprocal transplant experiment on a grasshopper, Chorthippus biguttulus, we found that environmental conditions significantly influenced not only body condition but also an important trait of male calling song, the amplitude of song. Although not significant, all other analysed physical and courtship song traits and attractiveness were superior in native than in transferred males. Thus, we concluded that local adaptation has a slight but consistent influence on a range of traits in our study populations, including male acoustic attractiveness. In our present study, we scanned male grasshoppers from the same two populations for amplification fragment length polymorphism (AFLP) loci connected with acoustic attractiveness to conspecific females. We found greater differences in allele frequencies between the two populations, for some loci, than are expected from a balance between drift and gene flow. These loci are potentially connected with locally adapted traits. We examined whether these alleles show the proposed genotype environment interaction by having different associations with attractiveness in the two populations. One locus was significantly related to sexual attractiveness; however, this was independent of the males’ population affiliation. Future research on the evolution of female choice will benefit from knowledge of the underlying genetic architecture of male traits under intraspecific sexual selection, and the ‘population genomics’ approach can be a powerful tool for revealing this structure.     

The last “pelycosaur”: a varanopid synapsid from the <Emphasis Type="Italic">Pristerognathus</Emphasis> Assemblage Zone,Middle Permian of South Africa

We report on a partial varanopid skull and mandible from the Pristerognathus Assemblage Zone of the Beaufort Group, in the South African Karoo Basin, which is probably latest Middle Permian (Capitanian) in age. This mycterosaurine is not only the youngest known varanopid from the Southern Hemisphere, but it is also the youngest known “pelycosaur” (i.e., non-therapsid synapsid). Like all other members of this clade of hypercarnivores, the teeth are strongly flattened, recurved, and have finely serrated cutting edges. The anterior dentary teeth form a caniniform region, and the splenial features a foramen intermandibularis oralis, the first ever to be described in a “pelycosaur.” The last varanopids were the smallest carnivores of latest Middle Permian continental faunas. Occupation of the small carnivore guild appears to have allowed varanopids to achieve a nearly cosmopolitan distribution throughout the Middle Permian, between the great Early Permian radiation of basal synapsids and the spectacular diversification of therapsid synapsids in the Late Permian and Early Triassic.     

让废电池"回家"

河南新乡的个体户田桂荣从1999年开始发起了回收废电池的活动,几百个废电池回收箱,几万份传单,随着坚持不懈的努力和人们环保意识的增强,她得到了越来越多的理解和和支持,废电池回收量日渐增长.然而,麻烦也来了:"这么多废电池到底咋办?真是难死我了!谁能告诉我处理废电池的好办法?"她这样说. 其实受此网扰的绝不只是田桂荣,废电池的回收利用一直是个难题.废电池有毒,不能乱扔,这大家都知道.于是很多学校、机关、商店都开展了废电池回收活动.但没过多久,各地的活动就陷入困境,因为收上来的废电池找不到出路,堆积如山,反成了负担……     

比尔&#183;金

比尔&#183;金先生（通常大家叫他Bill）现在是TNC（大自然保护协会）副总裁、全球首席生态保护执行官,统管TNC的全球保护事务（下设9大部门,涉及32个国家）,并负责推动机构最重要的保护项目和保护策略。比尔&#183;金在TNC任职已经超过12年,曾在机构内担任过多个重要的领导职务。     

斯塔夫罗&#183;迪马斯

斯塔夫罗&#183;迪马斯，欧盟环境专员，生于1941年4月，早年就读于雅典大学并取得法律与经济学学士学位，后在美国纽约大学取得法律硕士学位。1977年至2004年间，他曾作为新民主党代表连续十次被选为国会议员并且在希腊政坛处于领导地位，先后出任贸易部长、新民主党国会发言人、农业部长、工业能源及科技部长和新民主党秘书长等重要职位。     

洗涤之"伤"

毫无疑问，洗涤剂为个人保健和家居保洁提供了帮助，成为许多家庭的必备品。但这些洗涤剂潜在的化学危害却常常被人忽略。     

自然·水·人

人类社会向前发展,人向自然界的索取不断增加,对自然的干扰也逐步加剧,致使自然界的承受能力受到影响,人与自然的关系出现紧张。为此,人必须处理好与自然的关系,以免人的生存环境受到威胁。水是自然界的重要因素,和人的生存与人类社会的发展关系密切。由于用水量不断增加和用水不当,一些地区出现水资源危机,人在和水旱灾害进行抗争中,也出现了由于措施不当带来的人为加大灾害的问题。因此,人必须在处理好与自然关系的框架中,认真处理好与水的关系,以保障水资源的永续利用和人类社会的可持续发展。     

Individual protein balance strongly influences δ<Superscript>15</Superscript>N and δ<Superscript>13</Superscript>C values in Nile tilapia,<Emphasis Type="Italic"> Oreochromis niloticus</Emphasis>

Although stable isotope ratios in animals have often been used as indicators of the trophic level and for the back-calculation of diets, few experiments have been done under standardized laboratory conditions to investigate factors influencing ¹⁵N and ¹³C values. An experiment using Nile tilapia [Oreochromis niloticus (L.)] was therefore carried out to test the effect of different dietary protein contents (35.4, 42.3, and 50.9%) on ¹⁵N and ¹³C values of the whole tilapia. The fish were fed the isoenergetic and isolipidic semi-synthetic diets at a relatively low level. ¹⁵N and ¹³C values of the lipid-free body did not differ between the fish fed the diets with different protein contents, but the trophic shift for N and C isotopes decreased with increasing protein accretion in the individual fish, for N from 6.5 to 4 and for C in the lipid-free body from 4 to 2.5. This is the first study showing the strong influence of the individual protein balance to the degree to which the isotopic signature of dietary protein was modified in tissue protein of fish. The extrapolation of the trophic level or the reconstruction of the diet of an animal from stable isotope ratios without knowledge of the individual physiological condition and the feeding rate may lead to erroneous results.     

弗朗西丝&#183;拜内克

弗朗西丝&#183;拜内克，现任美国自然资源保护委员会（NRDC）主席。弗朗西丝在耶鲁大学获得学士学位。并获耶鲁大学森林与环境研究学院硕士学位。自1973年以来，弗朗西斯已经在NRDC工作了30多年，2006年成为主席之前，她担任该组织的执行总监8年，期间NRDC的成员达到300多个，比之前增加了一倍。