The evolution of the upright posture and gait—a review and a new synthesis

During the last century, approximately 30 hypotheses have been constructed to explain the evolution of the human upright posture and locomotion. The most important and recent ones are discussed here. Meanwhile, it has been established that all main hypotheses published until the last decade of the past century are outdated, at least with respect to some of their main ideas: Firstly, they were focused on only one cause for the evolution of bipedality, whereas the evolutionary process was much more complex. Secondly, they were all placed into a savannah scenario. During the 1990s, the fossil record allowed the reconstruction of emerging bipedalism more precisely in a forested habitat (e.g., as reported by Clarke and Tobias (Science 269:521–524, 1995) and WoldeGabriel et al. (Nature 412:175–178, 2001)). Moreover, the fossil remains revealed increasing evidence that this part of human evolution took place in a more humid environment than previously assumed. The Amphibian Generalist Theory, presented first in the year 2000, suggests that bipedalism began in a wooded habitat. The forests were not far from a shore, where our early ancestor, along with its arboreal habits, walked and waded in shallow water finding rich food with little investment. In contrast to all other theories, wading behaviour not only triggers an upright posture, but also forces the individual to maintain this position and to walk bipedally. So far, this is the only scenario suitable to overcome the considerable anatomical and functional threshold from quadrupedalism to bipedalism. This is consistent with paleoanthropological findings and with functional anatomy as well as with energetic calculations, and not least, with evolutionary psychology. The new synthesis presented here is able to harmonise many of the hitherto competing theories.     

Loft features reveal the functioning of the young pigeon’s navigational system

It is thought that young homing pigeons are able to use information acquired en route for their initial homeward orientation. However, the cues involved and mechanisms utilised are under discussion. Blocking light-dependent route-specific information during the first leg of an outward journey detour, together with analysis of pigeons that were raised under different loft conditions, allowed us to correctly evaluate the functioning of this mechanism and, more generally, the navigational map of birds. Pigeons from the same stock were raised and kept in two different lofts. The birds in the experimental groups were transported to the release sites via detours, and light-dependent information was denied during the first half of the outward journey (no compass information was available). Control birds were transported by the most direct route and had access to all available information. In general, the results showed that the low-loft birds preferred to use magnetic compass cues, whereas the high-loft birds preferred to use navigational map cues to collect information of the first part of the outward journey. The impairments observed in the homing performances of the experimental groups highlight the reliability of information collected inside the map area. Relevant to an understanding of the route-reversal mechanism was the evidence that this mechanism is able to function in the absence of compass information (birds raised in a wind-exposed loft show a detour effect). In systems where directional information could be provided by multiple sources, processing and extracting accurate course trajectories through a common mechanism may prove more efficient and reliable.     

A review of the contributions of Albert Einstein to Earth Sciences—in commemoration of the World Year of Physics

The World Year of Physics (2005) is an international celebration to commemorate the 100th anniversary of Einstein’s “Annus Mirabilis.” The United Nations has officially declared 2005 as the International Year of Physics. However, the impact of Einstein’s ideas was not restricted to physics. Among numerous other disciplines, Einstein also made significant and specific contributions to Earth Sciences. His geosciences-related letters, comments, and scientific articles are dispersed, not easily accessible, and are poorly known. The present review attempts to integrate them as a tribute to Einstein in commemoration of this centenary. These contributions can be classified into three basic areas: geodynamics, geological (planetary) catastrophism, and fluvial geomorphology. Regarding geodynamics, Einstein essentially supported Hapgood’s very controversial theory called Earth Crust Displacement. With respect to geological (planetary) catastrophism, it is shown how the ideas of Einstein about Velikovsky’s proposals evolved from 1946 to 1955. Finally, in relation to fluvial geodynamics, the review incorporates the elegant work in which Einstein explains the formation of meandering rivers. A general analysis of his contributions is also carried out from today’s perspective. Given the interdisciplinarity and implications of Einstein’s achievements to multiple fields of knowledge, we propose that the year 2005 serve, rather than to confine his universal figure within a specific scientific area, to broaden it for a better appreciation of this brilliant scientist in all of his dimensions.     

Allocation in ISO 14041—a critical review

The adequacy and feasibility of methods recommended for allocation by the current international standard on life cycle inventory analysis (LCI) are reviewed. The review is based on the view that an LCI should provide information on the environmental consequences of manipulating technological systems. On this basis, subdivision and allocation based on physical, causal relationships are adequate methods to deal with allocation problems for certain multifunction processes where the production volume of exported functions are unaffected. Further research is needed to develop methods that can deal with a broader range of processes. System expansion is an adequate method when exported functions are affected if data can be obtained for the competing production of the exported function, and if the data uncertainties are not too large. In LCI practice, system expansion is often based on inaccurate data on the effects on the exported functions as well as on the indirect effects of changes in the exported functions. Further research is needed to establish what data should be used at system expansion. Other approaches to the allocation problems are adequate only where the effects on the LCI results are small. The ISO procedure should be revised to take into account the type of information provided by the different methods.     

Algal-bloom control by allelopathy of aquatic macrophytes——A review

Algal-bloom control is an important issue for water environment protection as it induces several negative impacts on the lives of aquatic organisms, aquaculture, landscaping, and human health. The development of an environment-friendly, cost-effective, and convenient alternative for controlling algal bloom has gained much concern. Using the allelopathy of aquatic macrophytes as a novel and safe method for algal-bloom control is a promising alternative. This paper reviews the development and potential application about allelopathy of aquatic plants on algae, including the allelopathic research history, the potential research problems, the research methodology, and the reported aquatic macrophytes and their inhibitory allelochemicals. Potential modes of inhibition action of allelochemicals on algae, possible ways for application, and future development directions of research on algal-bloom control by aquatic macrophytes were also presented.     

Assessing river flood risk and adaptation in Europe—review of projections for the future

Flood damages have exhibited a rapid upward trend, both globally and in Europe, faster than population and economic growth. Hence, vigorous attempts of attribution of changes have been made. Flood risk and vulnerability tend to change over many areas, due to a range of climatic and nonclimatic impacts whose relative importance is site-specific. Flooding is a complex phenomenon and there are several generating mechanisms, among others intense and/or long-lasting precipitation, snowmelt, ice jam. Projected climate-driven changes in future flood frequency are complex, depending on the generating mechanism, e.g., increasing flood magnitudes where floods result of heavy rainfall and possibly decreasing magnitudes where floods are generated by spring snowmelt. Climate change is likely to cause an increase of the risk of riverine flooding across much of Europe. Projections of flood hazard in Europe based on climatic and hydrological models, reviewed in this paper, illustrate possible changes of recurrence of a 100-year flood (with probability of exceedance being 1-in-100 years) in Europe. What used to be a 100-year flood in the control period is projected to become either more frequent or less frequent in the future time horizon of concern. For a large part of the continent, large flooding is projected to become more commonplace in future, warmer climate. Due to the large uncertainty of climate projections, it is currently not possible to devise a scientifically-sound procedure for redefining design floods (e.g. 100-year flood) in order to adjust flood defenses. For the time being, we recommend to adjust design floods using a “climate change factor” approach.     

Sequential fractionation of reactive phosphorus in the sediment of a shallow eutrophic lake——Donghu Lake, China

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Fertility signaling—the proximate mechanism of worker policing in a clonal ant

In eusocial insects, the ability to regulate reproduction relies on cues that signal the presence of fertile individuals. We investigated the variation of cuticular hydrocarbons (CHCs) with reproductive status in Platythyrea punctata, an ant, in which all workers are capable of producing daughters from unfertilized eggs (thelytoky). Who reproduces is determined through dominance and worker policing. New reproductives, which developed their ovaries after separation from an old reproductive for a short period of time, were attacked by nonreproductives upon reintroduction into their colony. In contrast, aggression against new reproductives with fully developed ovaries, which had been separated over a longer period, was initiated by fights between old and new reproductives. CHC profiles varied with ovarian development. New reproductives were only attacked when they expressed a CHC profile similar to old reproductives, but not when it was similar to that of nonreproductives. CHCs appear to signal the fertility of individuals and induce policing behavior towards surplus reproductive workers.     

Non-migratory breeding by isolated green sea turtles (<Emphasis Type="Italic">Chelonia mydas</Emphasis>) in the Indian Ocean: biological and conservation implications

Green sea turtles (Chelonia mydas) are renowned for their long-distance migrations but have less fame for short-distance migrations or non-migratory behavior. We present satellite telemetric evidence from Cocos (Keeling) Islands, Indian Ocean for the first predominantly non-migratory green sea turtle (C. mydas) population. The mean migration distance from the nesting beach to the foraging grounds was 35.5 km with a maximum mean transit time of 3.4 days. The behavior of this population has major implications for our general understanding of green turtle behavior and their life cycle and for conservation. Firstly, these results indicate a level of juvenile or adult non-breeding homing behavior from the open ocean to foraging grounds adjacent to their natal nesting beach. Secondly, a non-migratory breeding phase reduces the consumption of reproductive energy utilized, potentially resulting in higher fecundity for this population. Thirdly, the close proximity of the nesting and foraging habitats allows for uniformity in management and conservation strategies rarely possible for wide-ranging green turtle populations.     

阿维菌素对原代培养神经细胞线粒体的影响

为了探讨阿维菌素(AVM)对体外培养神经细胞线粒体的影响.以10μg·L-1AVM对王鸽原代培养的神经细胞进行染毒,在作用0h、4h、12h和24h时分别采样,测定细胞相对存活率、线粒体琥珀酸脱氢酶活性、线粒体膜电位和线粒体超微结构的变化.结果显示,随着染毒时间的延长,细胞的相对存活率下降;线粒体琥珀酸脱氢酶活力降低;PI-/Rh123-细胞百分数增加;线粒体肿胀,结构不清晰,嵴断裂、溶解、基质中有片状空腔现象.研究结果表明,10μg·L-1AVM对王鸽脑神经细胞线粒体具有损伤作用.     

Attitudes to conservation and water consumption

Sydney's water supply is under great pressure as the demand continues to rise. Demand mitigation strategies have had some success, but domestic consumption remains high. This paper discusses the attitudes of households to their water consumption in a search for ways in which domestic demand for water may be reduced. Evidence on attitudes of households in different kinds of housing was obtained using a telephone interview survey supplemented by information derived from focus groups drawn from households in the same areas. The information was collected in a period when strong water use restrictions were in place and major arguments were being mounted in favour of water pricing as a way of moderating demand. The paper argues that the complexity of the forces shaping demand needs to be understood in the context of the socio-demographic composition of households in different kinds of dwellings, as well as the cultural, behavioural and institutional aspects of consumption, if public policy is to be successful in reducing consumption and/or providing alternative domestic supplies of potable water.     

连续施用养殖场鸡、鸽粪对土壤养分和重金属含量的影响

按照养殖场鸡粪和鸽粪含氮量计算其用量,进行连续6茬施用鸡粪和鸽粪（N 0～450 kg·hm^-2）菜心田间试验,研究对土壤养分和重金属含量的影响.结果表明,连续施用3茬鸡粪和鸽粪后,土壤铵态氮、硝态氮、有效磷及速效钾含量均明显提高,4种养分累积量随鸡、鸽粪用量增加而提高.由于后3茬遭遇较长时间强降雨,施用6茬后土壤硝态氮和速效钾含量不但比第3茬后有明显下降,甚至低于土壤原始含量,但铵态氮和有效磷含量仍比原始含量提高,而且含量增量随鸡、鸽粪用量增加而提高.鸡粪和鸽粪Pb、Cd、Cr含量及鸽粪As含量很低,连续施用6茬对土壤总Pb、总Cd、总Cr及总As含量影响不大,但2种粪肥Zn含量较高（分别为172.0、299.8 　mg·kg^-1）,施用6茬后土壤总Zn含量提高0.7～17.1 　mg·kg^-1.同时,鸡粪Cu（117.7 　mg·kg^-1）、As（39.6 　mg·kg^-1）含量相对较高,施用6茬后土壤总Cu、总As含量也有累积趋势.     

Optical properties of the uropygial gland secretion: no evidence for UV cosmetics in birds

Ultraviolet (UV) reflectance of the plumage is common in birds and plays an important role in sexual signalling. Recently, it has been proposed that birds are able to modify plumage UV reflectance by the application of uropygial gland secretion. Based on a survey of the optical properties of this secretion from 51 species belonging to 12 avian orders, we show that two main types of uropygial secretions exist, one predominantly found in passerines and one in non-passerines, both reducing relative UV reflectance of a white background (Teflon™ tape). We quantified how each type of secretion (exemplified by blue tit and mallard) affected feather UV reflectance. Both secretions reduced overall brightness and relative UV reflectance of white mallard feathers but hardly affected the reflectance of UV/blue blue tit crown feathers. According to models of avian colour vision, changes in reflectance due to application of the secretion were at or below the discrimination threshold of most birds. We conclude that the uropygial secretion is unlikely to play a major role in modifying plumage UV reflectance. However, the optical properties of the uropygial secretion may have been selected to interfere as little as possible with visual signaling through plumage reflectance. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

氯化甲基汞对大鼠海马c-jun蛋白表达的影响

为了探讨氯化甲基汞(MMC)对大鼠海马损伤的分子机制,应用免疫组织化学方法观察了氯化甲基汞对大鼠海马JUN蛋白表达的影响(对照组为0.9%生理盐水、暴露组浓度分别为0.05,0.5,5mg/kg;取样时间分别为20,60,240,1440min).结果发现,暴露组大鼠海马JUN蛋白表达均高于对照组,氯化甲基汞对大鼠海马JUN蛋白表达与其浓度之间有一定的剂量反应关系,表明即刻早期基因(c-jun)参与了氯化甲基汞对海马损害的毒性过程.