Cutaneous water loss and lipids of the stratum corneum in two syntopic species of bats

The lipid matrix of the stratum corneum (SC), the outer layer of the epidermis of mammals and birds, constitutes the barrier to diffusion of water vapor through the skin. The lipids of the SC are structured in the intercellular spaces of the mammalian epidermis in ordered layers, called lamellae, which have been postulated to prevent water loss. Lipids in the mammalian SC are mainly cholesterol, free fatty acids and ceramides, the latter forming the structural support for the lamellae. However, knowledge on how the lipid composition of the SC alters cutaneous water loss (CWL) in mammals is rudimentary, and is largely derived from studies on laboratory animals and humans. We measured CWL of individuals of two species of syntopic bats, Tadarida brasiliensis and Myotis velifer. In the first study of its kind on wild mammals, we correlated CWL with the lipid composition of the SC, measured using thin layer chromatography and high performance liquid chromatography coupled with atmospheric pressure photoionization mass spectrometry. Surface-specific CWL was 20.6% higher in M. velifer than in T. brasiliensis, although differences were not significant. Compared with individuals of M. velifer, individuals of T. brasiliensis had more classes, and a higher proportion, of polar ceramides in the SC, a feature associated with lower CWL. Individuals of T. brasiliensis also had a class of non-polar ceramides that presumably spans the lamellae and gives more cohesiveness to the lipid matrix of the SC. We conclude that qualitative and quantitative modifications of the lipid composition of the SC contribute to regulate CWL of these two species of bats.     

贵州山岚桥洞内动物重金属富集的初步研究

2009年6月对贵州安顺市山岚桥洞内软体动物和节肢动物进行了采集。共获标本637号,初步鉴定隶属于2门4纲7目12科25种,合并为螺类、马陆、盲蛛、斑灶马、山蛩虫5个类群。利用原子吸收光谱仪和原子荧光仪测定洞内水、土壤及洞穴中5个类群动物体内的Pb、Cd、Hg、As、Cu、Zn、Cr、Ni8种重金属含量,计算水、土壤中重金属在动物体内的富集系数。结果表明,水、土壤及动物体内的Zn含量最高,水样为112.90μg/L,土样为224.60mg/kg,5个动物类群体内,螺类146.80mg/kg,马陆252.20mg/kg,盲蛛556.80mg/kg,斑灶马233.30mg/kg,山蛩虫722.50mg/kg;5个类群动物对洞穴土壤中Cd、Cu和Zn有明显的富集作用,富集系数均大于1;对洞穴水中As、Cu、Zn、Ni等有明显富集作用,富集系数大于1000。同种动物类群对不同重金属的富集系数不同,不同类群对同种重金属元素的富集系数也有差别。洞穴动物对重金属的富集作用,除了与元素之间相互关联外,还与环境有密切关系。     

Faunal and taphonomic analyses of a Late Pleistocene bird-bone assemblage from a cave deposit in north-west Hungary

The paper presents a faunal and taphonomic discussion of the Late Pleistocene bird-bone assemblages excavated in Kálvária Cave n^o 4 near the city of Tatabánya in north-west Hungary. A total of 1150 complete and fragmentary avian remains were recovered from two locations on two separate occasions. Of these, 873 bones could be identified on the species-, family- or order-level. Fifteen of the identified 19 bird taxa could be determined on the species level and they indicate a habitat typical of forest margins. Several species yielded juvenile or subadult specimens, which in view of the breeding period means that these birds died during the summer, most probably between July and September.Each of the two assemblages had distinct characteristics. The high number of kestrel (Falco tinnunculus) long bones in Assemblage I generally included complete skeletal parts from subadult birds, suggesting a colony which bred in the cave, whose chicks died of natural causes. Even though the bones were exposed to a certain degree of water transport and soil corrosion, they were generally well preserved in the cave sediment. Size-characteristic analyses demonstrated that, in spite of the undeveloped morphological features, the sizes of limb bones usually corresponded to those of adult birds.The greater part of the material in Assemblage II originated from a stratified deposit and was dominated by small and fragmented remains of various taxa. The taxa which could be identified and the taphonomic features of the remains suggest that owl pellets formed the core of this bone assemblage.     

湖北郧西黄龙洞更新世晚期人类牙齿磨耗与使用痕迹

对2004—2006年在黄龙洞发现的7枚人类牙齿磨耗与使用痕迹的观察显示: 除具有正常牙齿相互接触造成的磨耗外, 黄龙洞人类牙齿还呈现出一些特殊的使用痕迹, 包括明显的前部牙齿釉质破损与崩裂、上颌侧门齿齿冠唇面釉质破损、上颌前部牙齿齿间邻接面沟等。根据这些牙齿使用痕迹集中在前部牙齿, 釉质破损与崩裂主要分布在靠近切缘的上颌门齿唇面及下颌门齿舌面的情况, 推测生活在黄龙洞的更新世晚期人类经常使用前部牙齿从事啃咬、叼衔、或剥离等动作, 并可能将前部牙齿作为工具使用。分布在前部牙齿的齿间邻接面沟提示当时人类经常从事剔牙活动。黄龙洞人类前部牙齿的使用痕迹与当时人类获取、处理及食用附着在骨骼上的筋或肉的动作密切相关, 当时人类的食物构成中可能包含有较多的肉类及粗纤维植物。     

麦积山石窟赋存环境中空气细菌的时空分布特征

【目的】空气微生物沉降及污染与文化遗产的微生物退化密切相关,本文对世界文化遗产地麦积山石窟赋存环境空气中细菌浓度和群落结构的季节性变化特征进行了系统研究,为石窟环境监测预警和文物预防性保护提供依据。【方法】利用生物气溶胶采样器,在2016年春、夏、秋和冬季分别采集空气样品;基于传统培养方法获得空气中细菌浓度及纯培养菌株;通过提取基因组DNA、扩增细菌16S rRNA、测序和系统发生树等分子技术研究细菌群落时空动态变化规律;结合环境监测数据,分析影响遗产地空气细菌变化的主要因素。【结果】监测期内,空气细菌浓度在(281.20–1409.20)CFU/m3之间,最高浓度出现在MJ4处的夏季,最低浓度出现在MJO处的春季;具有明显季节性变化特征,在空间层位分布上有所差异,但不显著(P0.05)。培养的细菌菌株经鉴定属于4个门11个属;芽孢杆菌属(Bacillus)、Paenarthrobacter、节杆菌属(Arthrobacter)、薄层菌属(Hymenobacter)和考克氏菌属(Kocuria)等为优势属。【结论】麦积山石窟空气细菌群落结构具有明显的季节性和空间分布动态变化特征;在石窟不同层位,空气中细菌群落分布与相对湿度、温度与降雨量相关;部分细菌种属如芽孢杆菌属、微球菌属(Micrococcus),为壁画及彩塑生物腐蚀的潜在病害菌;麦积山石窟及周边环境空气细菌的监测可为石窟保护和旅游开放管理提供重要参考。     

Belowground carabid beetle diversity in the western Palaearctic - effects of history and climate on range-restricted taxa (Coleoptera, Carabidae)

Broad-scale patterns of subterranean diversity are a fascinating but neglected part of biodiversity research. Carabid beetles adapted to belowground habitats form a particularly species-rich part of the subterranean fauna. We studied large-scale diversity patterns of these belowground carabids across the western Palaearctic and evaluated potential impacts of historical and contemporary environmental conditions on the distribution of these taxa, using available species richness and environmental data at country level. Regression modelling and variation partitioning showed a strong relationship between species richness and range in elevation. Potential effects of climatic variables, mainly those related to ambient energy input, were much weaker. We discuss the implications of this combination of effects, which suggests, concordant with the absence of subterranean carabids in northern and highest richness in southern Europe, a strong prevailing influence of historical processes on current richness distributions of these taxa. Previous studies did not provide clear indications for such an influence. In contrast to more mobile and widespread carabid beetles, dispersal limitation due to high adaptation of belowground carabids to subterranean habitats has probably hindered their re-colonization of former permafrost and glaciated regions. Hotspots of highest belowground diversity are located in regions with an assumed long-term stability of environmental conditions, correlating with patterns of other dispersal-limited taxa such as many endemic plants. Our study provides important new information in the discussion of potential determinants of the distinct geographic patterns of belowground diversity. Moreover, it contributes to a better understanding of range size related differences previously found in the distribution of diversity and environmental dependencies of widespread and range-restricted species within the highly diverse carabid beetles.     

Life on the edge: hydrogen sulfide and the fish communities of a Mexican cave and surrounding waters

Most eucaryotic organisms classified as living in an extreme habitat are invertebrates. Here we report of a fish living in a Mexican cave (Cueva del Azufre) that is rich in highly toxic H₂S. We compared the water chemistry and fish communities of the cave and several nearby surface streams. Our study revealed high concentrations of H₂S in the cave and its outflow (El Azufre). The concentrations of H₂S reach more than 300 μM inside the cave, which are acutely toxic for most fishes. In both sulfidic habitats, the diversity of fishes was heavily reduced, and Poecilia mexicana was the dominant species indicating that the presence of H₂S has an all-or-none effect, permitting only few species to survive in sulfidic habitats. Compared to habitats without H₂S, P. mexicana from the cave and the outflow have a significantly lower body condition. Although there are microhabitats with varying concentrations of H₂S within the cave, we could not find a higher fish density in areas with lower concentrations of H₂S. We discuss that P. mexicana is one of the few extremophile vertebrates. Our study supports the idea that extreme habitats lead to an impoverished species diversity.     

Art and the Middle-to-Upper Paleolithic transition in Europe: comments on the archaeological arguments for an early Upper Paleolithic antiquity of the Grotte Chauvet art

The spectacular art of the Grotte Chauvet stands out among all other examples of Aurignacian art, which are restricted to a handful of sites in other regions of western and Central Europe, which take the form of sophisticated carvings on organic materials and of simple engravings on rockshelter walls. Given its sophistication, Chauvet has understandably come to feature prominently in debates as to the nature of human symbolic origins, the behavioral capacities of Homo sapiens, the nature of the dispersal of modern humans across Europe, and the possibly contemporary extinction of Homo neanderthalensis. Significant objections to such an antiquity have, however, been made in recent years on the grounds of the style, themes, and technical practice of the art itself, and on the grounds of the AMS radiocarbon dating program that was first seen to suggest an early Upper Paleolithic age. To date, no attention has been paid to claims for an Aurignacian age on specifically archaeological grounds. Here, I undertake a critical examination of the archaeology of the cave and its wider region, as well as attempts to verify the antiquity of the art on the basis of comparison with well-dated Aurignacian art elsewhere. I conclude that none of the archaeological arguments withstand scrutiny and that many can be rejected as they are either incorrect or tautologous. By contrast, hypotheses that the art is of Gravettian-Magdalenian age have not been successfully eliminated. The age of the art of the Grotte Chauvet should be seen as a scientific problem, not an established fact. While it may prove impossible to prove an Aurignacian age for some of the Chauvet art I suggest a set of expectations that would, in combination, strengthen the robusticity of the ‘long chronology’ argument. The onus is upon Chauvet long chronologists to do this, and until they do, we must conclude that the art of the Grotte Chauvet is not dated, and very possibly much younger than claimed.