Length of index and ring fingers differentially influence sexual attractiveness of men’s and women’s hands

Humans show intra- and intersexual variation in second (2D) relative to fourth (4D) finger length, men having smaller 2D:4D ratio, possibly because of differential exposure to sex hormones during fetal life. The relations between 2D:4D and phenotypic traits including fitness components reported by several studies may originate from the organizational effects that sex hormones have on diverse organs and their concomitant effect on 2D:4D. Evolutionary theory posits that sexual preferences are adaptations whereby choosy individuals obtain direct or genetic indirect benefits by choosing a particular mate. Since sex hormones influence both fitness and 2D:4D, hand sexual attractiveness should depend on 2D:4D, a hypothesis tested only in one correlational study so far. We first presented hand computer images to undergraduates and found that opposite-sex hands with long 2D and 4D were considered more sexually attractive. When we experimentally manipulated hand images by increasing or decreasing 2D and/or 4D length, women preferred opposite-sex hands that had been masculinized by elongating 4D, whereas men avoided masculinized opposite-sex right hands with shortened 2D. Hence, consensus exists about which hands are attractive among different opposite-sex judges. Finger length may signal desirable sex hormone-dependent traits or genetic quality of potential mates. Psychological mechanisms mediating hand attractiveness judgments may thus reflect adaptations functioning to provide direct or indirect benefits to choosy individuals. Because the genetic mechanisms that link digit development to sex hormones may be mediated by Hox genes which are conserved in vertebrates, present results have broad implications for sexual selection studies also in nonhuman taxa.     

Age-specific filial cannibalism in a paternal mouthbrooding fish

Entire-brood cannibalism by mouthbrooding males of the cardinal fish Apogon doederleini was investigated in temperate waters of southern Japan during two breeding seasons. The rate of cannibalism was 17–18% in each season and did not differ among age-groups. However, the seasonal pattern of cannibalism differed markedly among age-groups: young (1- and 2-year-old) males frequently cannibalized early broods, especially the first brood, of the season, whereas cannibalism by middle-aged (3- and 4-year-old) and old (5- and 6-year-old) males mainly occurred late in the breeding season. We explain this difference in terms of trade-offs between current and future reproduction. Young males, whose future reproductive success is enhanced by the growth increment, may allocate more time and energy to growth by cannibalizing early broods. In contrast, for older males who have had more breeding cycles and grow little, cannibalism could be a way to reverse the deterioration in their somatic condition that occurs as the breeding season progresses. It is also likely that the current reproductive loss entailed by the cannibalism is effectively compensated by quick re-mating with another female. Received: 24 February 1997 / Accepted after revision: 20 July 1997     

All at sea: aquatic life modifies mate-recognition modalities in sea snakes (Emydocephalus annulatus, Hydrophiidae)

Alternative sensory modalities (e.g. vision, chemoreception) differ in the spatial scale, permanence and reliability of cues they provide to mate-searching males. Males of terrestrial snake species use chemoreception to locate females over large distances, but phylogenetic shifts to aquatic life render such cues unavailable. Do male sea snakes use alternative modalities for identifying potential sexual partners and if so, are the novel systems as effective for mate-finding as the ancestral ones? Observations and experiments show that free-ranging male turtle-headed sea snakes (Emydocephalus annulatus) in shallow-water reef habitats in New Caledonia use visual cues (including size, movement and color pattern) to assess whether snake-shaped objects are potential sexual partners. Skin lipids (pheromones) are important only after the male comes into physical contact with the stimulus. Visual cues provide unreliable information about potential mates, and function over short distances only (generally, <1 m). In consequence, mate-searching male snakes frequently failed to find nearby females, rarely managed to maintain contact with females they did find, and wasted time and energy investigating inappropriate stimuli (e.g. fishes, sea cucumbers, divers). The loss of effective pheromonal mate-location systems means that mate recognition by aquatic snakes functions over smaller distances than in their terrestrial relatives. Phylogenetic transitions among habitat types thus may directly modify central features of the mating system.     

Is female promiscuity constrained by the presence of her social mate? An experiment with bluethroats <Emphasis Type="Italic">Luscinia svecica</Emphasis>

Extra-pair paternity is common in birds and much research has focussed on the selective advantage of extra-pair matings for both sexes. In contrast, little attention has been given to the fact that in most species the majority of offspring are sired by the social male. We investigated whether extra-pair matings of female bluethroats (Luscinia svecica) are constrained by the presence of the pair male, by detaining males in cages on their territories for one morning during the peak of female fertility. The proportion of offspring sired by extra-pair males was higher in broods where males had been detained (35%) than in control broods (16%), while the proportion of broods that had at least one extra-pair offspring did not differ significantly between experimental (65%) and control broods (44%). Within the experimental group, levels of extra-pair paternity were not related to the day of experiment in relation to start of egg laying, but males caught early in the morning lost more paternity than males caught later on. Our results show that pair males exert constraints on the frequency of extra-pair paternity by being present during the period of peak fertility, which could be a direct effect of their mate guarding effort and/or due to an advantage in sperm competition for pair males.     

Resilience-based approach to safety barrier performance assessment in process facilities

The performance assessment of safety barriers is essential to find vulnerable elements in a safety barrier system. Traditional performance assessment approaches mainly focus on using several static indicators for quantifying the performance of safety barriers. However, with the increasing complexity of the system, emerging hazards are highly uncertain, making it challenging for the static indicators to assess the performance of safety barriers. This paper proposes a resilience−based performance assessment method for safety barriers to overcome this problem. Safety barriers are classified according to their functions first. The dynamic Bayesian network (DBN) is then introduced to calculate the availability function under normal and disruption conditions. The ratio of the system's availability, when affected by the disruption, to the initial availability, is used to determine the absorption capacity of the system. The ratio of the quantity of availability recovery to the total quantity of system represents the adaptation and restoration capacity of the system. The system's resilience is represented by the sum of absorption, adaptation, and restoration capacities. The wax oil hydrogenation process is used to demonstrate the applicability of the proposed methodology.     

有机物料投入对喀斯特地区土壤磷素赋存形态与含phoD基因细菌群落的影响

针对喀斯特地区有机物料盈余、土壤养分贫瘠和易流失的特点,设置长期有机物料还田小区定位试验,试验包括6个处理：不施肥对照（CK）、无机肥（NPK）、无机肥+玉米秸秆（NPKS）、无机肥+农家肥（NPKM）、无机肥+滤泥（NPKL）和无机肥+甘蔗灰（NPKA）.研究不同有机物料投入对土壤磷赋存形态和磷活化功能微生物（含有机磷矿化基因细菌）群落结构的影响.通过3 a断续的观测,结果表明,土壤全磷（TP）、速效磷（Olsen-P）和二钙磷（Ca₂-P）含量呈逐年增加趋势,而氯化钙磷（CaCl₂-P）含量呈先降低再增加的趋势;与不施肥对照相比,有机物料投入尤其是滤泥配施能显著提高土壤全氮（TN）、TP、Olsen-P、CaCl₂-P和Ca₂-P含量,其次是甘蔗灰和农家肥配施处理;相关分析表明,CaCl₂-P、Ca₂-P和Olsen-P均与土壤交换性钙（Ca-ex）含量显著正相关;冗余分析（RDA）表明土壤TN、Ca-ex、有机碳（SOC）和土壤全钾（TK）含量是影响土壤磷组分的关键因子.高通量测序分析含有机磷矿化基因（含phoD基因）细菌群落结果表明,与不施肥对照相比,秸秆还田配施无机肥处理显著增加土壤含phoD基因细菌丰富度,但各处理间含phoD基因细菌群落结构无显著差异.RDA分析结果表明,土壤Ca-ex、TK、Olsen-P、pH和SOC是驱动含phoD基因细菌群落变化的关键因子.总体上看,无机肥配施滤泥、甘蔗灰和农家肥是广西喀斯特地区农田土壤较为合适的养分管理方式.研究可为喀斯特地区有机废弃资源利用与土壤磷素管理提供科学依据.     

Is Shennongjia a Suitable Site for Reintroducing Giant Panda: An Appraisal on Food Supply

The giant panda was found on Mount Shennongjia in Central China for thousands of years but vanished in the late 19th century. The possibility for reintroducing the giant panda in Shennongjia is discussed in terms of food availability, carrying capacity, and predicted bamboo flowering. Three species (Fargesia spathacea, F. murielae, and Yushania confusa) are considered the preferred forage bamboos, which could feed 193–223 giant pandas. However, in 1879–1888 these three species synchronously flowered and died back. In the past, such bamboo flowering usually forced the panda to migrate to a new habitat where forage bamboos were available. But since the 19th century, Shennongjia has become separated from other panda habitats by densely populated agricultural zones. Multi-species flowering of the forage bamboo and isolating of the habitat might caused the extinct of the giant panda in Shennongjia. If the flowering cycle of the bamboo is genetically fixed, the next synchronous flowering of two staple food species (F. spathacea and F. murielae) may occur in 2436–2439. It means that the food supply is dependable in Shennongjia for reintroducing the giant panda before 2436.     

Spotted bowerbirds<Emphasis Type="Italic"> Chlamydera maculata</Emphasis> do not prefer rare or costly bower decorations

Females target elaborate secondary sexual traits to acquire either direct benefits, represented or provided by the trait, or indirect benefits usually in the form of genetic components. The link between a males trait and his potential genetic contribution is often unclear. Bowers are extreme examples of secondary sexual traits, built and decorated by males and targeted by females. However, why females should base their mate choice on such structures is unclear. One of the simplest suggestions is that bowers are sites where males exhibit collections of objects that are inherently highly costly, indicating male quality to the choosy female. Such costs can be imposed in two ways, acquisition from the local area, and maintenance in the face of degradation. We studied bowers of spotted bowerbirds Chlamydera maculata at three sites in central Queensland and tested whether components of the bowers that best predict mating success were some of the most costly in the local environment by measuring their abundance, physical dimensions and rate of decay. We also tested whether rare objects per se found on the bowers, were relatively good predictors of mating success. Finally, we experimentally tested whether males preferentially chose rare, and hence costly, objects to use as decorations. We found that objects used on bowers were not unusually costly. Specific objects identified as good predictors of mating success were also some of the more common objects found in the area. They were not the largest objects used on bowers and decayed slowly relative to other objects available for use as decorations. Rare objects in general were not good predictors of mating success and males did not prefer to use rare objects when offered choices. In conclusion, we found no support for the theory that by simply inspecting numbers of decorations and assessing their costs of acquisition and maintenance females can easily obtain information regarding the owners quality. This is due to the fact that decorations used by spotted bowerbirds are not inherently costly.Communicated by J. Graves     

垃圾渗滤液对土壤铁锰有效性及地下水质的影响

受垃圾渗滤液影响,垃圾场周边土壤有机物含量增加。试验结果显示,随着土壤有机物含量的增加,土壤中有效态铁锰含量增大。垃圾场周边土壤中渗滤液有机物和金属铁锰共存时,大量的有机物质能活化土壤中的铁锰,增加其有效性,增强其在土壤中的迁移能力。从而造成垃圾场地下水较严重的铁锰污染。     

Changes in groundwater levels and the response of natural vegetation to transfer of water to the lower reaches of the Tarim River

Restoration and reconstruction of the degraded Tarim River ecosystem is an important challenge.A goal of an ecological water conveyance project is to protect and restore the natural vegetation in the lower reaches of Tarim River by transferring water from Bosten Lake,through the river channel,to the lower reaches.This study describes the changes in groundwater depth during the water transfer and the respondence of riparian vegetation to alterations in groundwater levels.The results indicate that groundwater depth along the Tarim River channel has a significant spatial-temporal component.Groundwater levels closest to the river channel show the most immediate and pronounced changes as a response to water transfer while those further away respond more slowly,although the observed change appears to be longer in duration.With a rise in the groundwater level,natural vegetation responded with higher growth rates,biomass and biodiversity.These favorable changes show that it is feasible to protect and restore the degraded natural vegetation by raising the groundwater depth.Plant communities are likely to reflect the hysteresis phenomenon,requiring higher water levels to initiate and stimulate desired growth than what may be needed to maintain the plant community.Because different species have different ecologies,including different root depths and densities and water needs,their response to increasing water availability will be spatially and temporally heterogenous.The response of vegetation is also influenced by microtopography and watering style.This paper discusses strategies for the protection and restoration of the degraded vegetation in the lower reaches of the Tarim River and provides information to complement ongoing theoretical research into ecological restoration in arid or semi-arid ecosystems.