Comparative morpho-physiology of the metapleural glands of two Atta leaf-cutting ant queens nesting in clayish and organic soils

Queens of leaf-cutting ants found their nests singly, each consisting of a vertical tunnel and a final horizontal chamber. Because of the claustral mode of nest founding, the queen and/or her initial fungus garden are exposed to threats imposed by several soil pathogens, and the antibiotic secretions produced by their metapleural glands are considered a main adaptation to deal with them. Nests of two Atta leaf-cutting ant species, Atta vollenweideri and Atta sexdens rubropilosa, occur in different soil types, alfisols and oxisols. Their queens are known to excavate the initial nest in different soil horizons, clayish and organic, respectively, which differ in their fertility and associated microbiota. The aim of the present study was to comparatively investigate the morpho-physiology of the metapleural glands in queens of A. vollenweideri and A. sexdens rubropilosa, addressing the question whether the distinct selective pressure imposed by the microbiota in the two different soil types led to morpho-physiological differences in the metapleural glands that were consistent with their antiseptic function. The results revealed that metapleural glands of A. sexdens rubropilosa have a larger number of secretory cells, and consequently a higher production of antibiotic secretions, which may have been selected to allow nest founding at the superficial horizon of oxisols rich in organic matter and microorganisms. Glands of A. vollenweideri, on the contrary, presented fewer secretory cells, suggesting less production of antibiotic secretions. We argue that the excavation of deep founding nests in A. vollenweideri was primarily selected for during evolution to avoid the risk posed by flooding, and further hypothesize that a reduced number of cells in their metapleural glands occurred because of a weak pathogen-driven selective pressure at the preferred soil depth.     

四川都江堰东方草鸮的繁殖记录

<正>东方草鸮(Tyto longimembris)隶属于鸮形目草鸮科,共有6个亚种的分化,我国分布的2个亚种为T.l.chinensis和T.l.pithecops。东方草鸮在我国主要分布于西南和华南(chinensis)以及台湾(pithecops),国外分布于印度次大陆、东南亚、菲律宾、新几内亚岛和澳大利亚(del Hoyo et al.1999,郑光美2011)。在《中国鸟类分类与分布名录》(第二版)中,东方草鸮的分布区并不包括四川省。实际上,早在2000年时就曾有报道称在四川省南充市高坪区发现草鸮的分布(胡锦矗2000),一直未能引起关注。有关东方草鸮繁殖生物学的资料,大多来自国外的     

急性冠脉事件发病特点及院前急救对策

目的分析我院急诊科对急性冠脉事件包括急性心肌梗死（AMI）和不稳定型心绞痛（UAP）的院前急救情况,就其存在的问题提出对策。方法回顾性分析1989～2010年救治的急性冠脉事件患者166例临床资料,其中AMI患者72例,UAP患者94例。结果急性冠脉事件发生率占急性心脏事件的48．8％,其院前急救率为31．3％（52／166）,院前抢救成功率为82．69％（44／52）。结论（1）急性冠脉事件的院前急救率仍低,主要与患者及其家属不了解急性冠脉综合征的发病先兆和表现等相关知识以及呼救意识有关,因此加强相关知识的群众性普及教育迫在眉睫。（2）缩短出诊半径、加强医务人员对急诊处理特别是院前处理急性冠脉事件知识的培训、完善院前急救设备,是提高急性冠脉事件院前抢救成功率的保障。     

Analyse des artefacts lithiques du site de Longgupo

Excavation has enabled recovery of 854 artifacts within 30 archaeological levels in the south sector and 11 in the north (chapter 3). These levels are quite probably contemporaneous, or even the same. The quantitative disparity in the number of strata between the two sectors is simply due to the fact that only the lower half of the northern zone was completely investigated. Similarly, the number of artifacts recovered by level varies according to the surface area excavated, although is some cases the density of material is significant despite the small area excavated, for example stratum C IV 5 which contains 174 lithic artifacts in 2 m². Before undertaking the technological analysis of the artifacts, given the preceding polemics provoked by the great age of this site and its implications for the spread of the first populations out of Africa, it was deemed important to carry out a plurifactorial analysis combining all of the data related to: the stratigraphy, taphonomic processes (post-depositional disturbance), analysis of natural processes that may have produced eoliths, experimentation and techno-functional analysis of the material. The stratigraphy shows clear interstratifications of fine and coarse fluviatile levels with often very clear particle size sorting of the coarse fraction. The archaeological material is typically found at the interface of these strata, either at the base of a clayey matrix, overlying a preceding coarse level, or in the superficial part of a sandy-clay deposit underlying coarse deposits. Post-depositional disturbance revealed during the new excavations in 2003–2006 cannot alone be the cause of eoliths. Excavation of a 6 m² zone in the modern river bed, located below the site, has demonstrated that the technological traits of eoliths recovered cannot in any way be confused with the technological traits of the artifacts recovered at the site itself. Similarly, viewed quantitatively, the 6 m² zone excavated in the river bed yielded around 20 eoliths while the 30 m² zone excavated at the site yielded 854 artifacts, one stratum alone yielding 184 artifacts in a 3 m² zone. During the experimental phase, adopting the same conditions of procuring raw material, from the same river bed, we very quickly realized the rarity of types of adequate volume that had been generally used at the site and the need to use certain operational processes to create such a form. In addition, the hardness and presence of several natural fracture planes in the Triassic limestone explain the choice of different operational processes and the very high number of knapping accidents, including those occurring during bipolar percussion. Although 90% of the raw material used was cobbles or broken blocks of local Triassic limestone, 10% of the tools were made on exogenous raw materials – siliceous or gravelly limestone, quartzitic sandstone, chert, volcanic rock – that are absent from the immediate environment of the site. These raw materials were brought to the site in the form of tools: worked cobbles, large retouched flakes, backed double-truncated flakes, a plaquette with a lateral bifacial edge, etc. The 854 artifacts have been classified into six object classes: worked cobbles with transversal edge (39%), worked cobbles with lateral edge (2%), unipolar flakes (27%), bipolar objects (half-blocks, half-cobbles including some flat “split” cobbles, “orange slices”, flakes and diverse fragments) (17%) and fragments resulting from knapping of blocks or cobbles (13%), hammerstone (2%). When the frequencies of these classes are calculated for each of the sectors, percentages are similar, indicating a high degree of homogeneity in the archaeological assemblages at the site. The situation is somewhat different when assemblages are compared within a single sector. Slight differences appear in the percentages of bipolar pieces and unipolar flakes. These differences seem to be random, like the frequency rate of knapping accidents in bipolar reduction, or economic, such as the choice of operational schemes to create worked cobbles based on the availability of suitable raw materials. The technological affinity between each of the archaeological assemblages tends to demonstrate great stability in technological knowledge through time. The class of worked cobbles is by far the most important and, apart from a few flakes produced intentionally, it appears to group all of the tools. To avoid placing these tools in a restrictive, semantically meaningless, class, we prefer the concept of matrix to the term worked cobble. A matrix is a structured arrangement of a series of technological traits, in a form as close as possible to that of the future tool. The matrix phase leads to the tool production phase, which may be unnecessary if the matrix phase includes fictionalization. In other words, the concept of matrix enables separating the phase of preparing a predetermined volume, such as a blade, Levallois flake or bifacial piece, from the tool production phase, consisting in creating the type of transformative edge intended, if necessary. The tool is thus an artifact of a specific form with an integrated edge and an operational scheme both specific to the function attributed to it and means of use associated with the form. Observed variability relates to: the size of the volume ranging from to 20, morphology, the form of the line formed by the edge which can in frontal view be curved, linear, sinuous or denticulated, and in transversal view curved, linear, sinuous or saw-toothed, and the length of the edge ranging from 1 to 10. Matrices with a simple bevel are distinguished from double bevels. In the framework of the technological analysis of production schemes to produce matrices with a simple bevel, a broad range of variability in production schemes can be observed, divided arbitrarily into two stages. The first stage consists in creating as closely as possibly the technological traits of the future matrix due to five general schemes. The first scheme (A) consists in selecting a cobble or block naturally possessing at least some of the technological traits needed. The missing traits are added by various preparations, including bipolar percussion 3 times out of 5. The second scheme (B) consists in knapping a flake from the block with some of the technological traits required for the matrix present on one of its surfaces. The third scheme (C) consists in the choice of a plaquette from which a bipolar shock creates the main traits of the matrix. The fourth scheme (D) consists in choosing a volume very similar to the intended matrix. The fifth and final scheme (E) consists in knapping a flake with technological traits very different from those intended. Depending on the distance between intention and realization, a second stage may be necessary. In general, this second stage perfects or creates the intended active edge, which is rarely obtained in the first stage. To produce a matrix with a double bevel, it is sometimes necessary to add an intermediate stage in order to prepare the second bevel. The first stage remains the same, with the use of the five operational schemes. By contrast, a clear difference exists in the percentages for the use of these schemes. For a matrix with a simple bevel, scheme A is dominant, followed by scheme D, while the situation is reversed for a matrix with a double bevel, where scheme D is dominant. Unipolar flakes, representing 27% of the assemblage, are produced in three different ways. The most important is flakes resulting from matrix production. The two others are flakes produced during different knapping schemes, some flakes in relation to the few cores present, other flakes in exogenous raw materials produced elsewhere and generally much larger. The other classes are dominated by bipolar products resulting essentially from knapping accidents. To summarize, these assemblages are characterized by: the search for tools differentiated by form and active edges; more than 90% of the tools made on two kinds of supports: a matrix with a simple bevel or a double bevel; matrices obtained using different operational schemes successively associating if necessary a knapping stage and a shaping stage. While the Triassic limestone is hard and thus imposes a strong constraint on knapping, the range of operational schemes appears to have been a “cultural” response diversified to this constraint and the presence of tools on exogenous raw materials. At the scale of China, comparison of this industry is impossible since it is the only site of this age and to contain so much material. The site of Majuangou, the only site of similar caliber, is younger by several hundred thousand years and is located several thousand kilometers to the north, making comparisons meaningless. We note only that most of the tool supports at Majuangou are knapped flakes. On an inter-continental scale, the comparison of sites of equal age is more promising. But lithic analyses are based on different methods, preventing comparison of similar data. However, if we make a simple summary of the data available, we can first say that in Africa, during these periods, different development technological stages were present and stages that are considered more evolved are manifestly less common using our approach. While these stages are more or less contemporaneous, which counters the idea of uniqueness, they would more surely be evidence of populations that were not in direct contact and had separate lines of development. In Asia, the Longgupo industry evidences a different technological option than that of contemporaneous populations in Africa. By contrast, when we take into account its developmental stage, we realize that this is an “evolved” stage in which the form of the support of the future tool is predominant. If we compare Africa and Asia in terms of stages, we are a priori at the same stage with different options being selected.     

Le gisement acheuléen de plein air de La Garde (Loire). Remarques sur une série lithique acheuléenne entre Rhône et Loire

The lithic assemblage of La Garde offers the opportunity to observe a Final Acheulean series located in the Loire department (south-east France). The site was probably a multi-activity place asking large tools and flakes, according to the strategies used by humans. Three main categories of large bifacial tools mainly made of flint can be described, with a triangular or oval shape and with a transversal cutting edge. These tools are more bifacial-tools than bifaces through the kind of shaping and the retouches on the cutting edges. The Levallois flaking is associated to various other types of knapping. The site, located along a small valley, suggests a human circulating between the Saône-Rhône corridor and the interior basins of the Massif Central Mountains. The Rhodanian corridor yielded little evidence of Acheulean settlements while in the Centre of France, they are numerous. La Garde proves that systematic prospecting in this area will permit in future to complete the map of the Acheulean occupations in south-east France.     

CST-II’s recognition domain for acceptor substrates in α-(2→8)-sialylations

CST-II is a bacterial sialyltransferase known for its ability to perform α-(2→8)-sialylations using GM₃ related trisaccharide substrates. Previously, we probed the enzyme’s substrate specificity and developed an efficient synthesis for α-(2→8)-oligosialosides, and we suggested that CST-II could have a very small substrate recognition domain. Here we report our full studies on CST-II’s recognition feature for acceptor substrates. The current study further demonstrates the versatility of CST-II in preparing complex oligosaccharides that contain α-(2→8)-oligosialyl moieties.     

Rodent foraging is affected by indirect, but not by direct, cues of predation risk

We used foraging trays to determine whether oldfield mice, Peromyscuspolionotus, altered foraging in response to direct cues of predationrisk (urine of native and nonnative predators) and indirectcues of predation risk (foraging microhabitat, precipitation,and moon illumination). The proportion of seeds remaining ineach tray (a measure of the giving-up density [GUD]) was usedto measure risk perceived by mice. Mice did not alter theirGUD when presented with cues of native predators (bobcats, Lynxrufus, and red foxes, Vulpes vulpes), recently introduced predators(coyotes, Canis latrans), nonnative predators (ocelots, Leoparduspardalis), a native herbivore (white-tailed deer, Odocoileusvirginianus), or a water control. Rather, GUD was related tomicrohabitat: rodents removed more seeds from foraging trayssheltered beneath vegetative cover compared with exposed traysoutside of cover. Rodents also removed more seeds during nightswith precipitation and when moon illumination was low. Our resultssuggest that P. polionotus used indirect cues rather than directcues to assess risk of vertebrate predation. Indirect cues maybe more reliable than are direct scent cues for estimating riskfrom multiple vertebrate predators that present the most riskin open environments.     

OEP及卵黄浓度对蓝狐冻融精子质量的影响

人工采取 6只优质芬兰雄性蓝狐精液 ,利用不同OEP及卵黄含量的Tris 果糖 -柠檬酸钠稀释液稀释 ,制成细管冻精 ,透射电镜下观察精子冷冻前后质膜和顶体超微结构 ,荧光免疫方法检测不同培养时间冻融精子的质量。结果表明 ,蓝狐精子顶体外膜双层膜的厚度为 0 0 2 0 μm ,冷冻 -解冻过程中易发生质膜膨胀、顶体外膜融合现象。顶体产生的囊泡分两种类型 ,一种是体积较大的中空囊泡 ,平均直径为 1 2 5 μm。另一种是体积较小的实体囊泡 ,内充满顶体内容物 ,平均直径为 0 83μm ,两种囊泡的数量不定。OEP能有效抑制顶体囊泡形成 ,影响顶体囊泡类型、体积大小及囊泡数量 ,添加适宜剂量OEP能使顶体囊泡的体积明显缩小 ,囊泡的总数及中空囊泡的数量显著降低。蓝狐冻融精子质量与OEP及卵黄剂量有关 ,在卵黄存在的前提下 ,OEP有利于维持冻融过程中质膜 (5 6 3% )、顶体的完整性 (5 7 8% ) ,显著提高冻融精子活力 (5 4 7% )。在蓝狐精液稀释液中 ,OEP、卵黄的适宜含量分别为 1 %、 2 0 %     

海水养殖真鲷弧菌病病原菌外毒素的理化特性

对最小弧菌Vm Pm毒素的分子量、分子结构及氨基酸组分进行了测定 ,同时还研究了温度、酸碱度及胰酶等因子对该毒素生物学活性的影响。研究结果表明 ,该毒素为单一的多肽 ,不具备典型的细菌毒素A、B亚基结构 ,分子量为 30 4 5 6kD ;毒素蛋白含天冬氨酸、苏氨酸、丝氨酸及半胱氨酸等 15种氨基酸 ,其中天冬氨酸的含量最多 ,半胱氨酸的含量最少 ,酸性氨基酸含量为 2 6 6 % ,碱性氨基酸含量为 14 4 % ,疏水性氨基酸含量为 33 4 % ;毒素活性的最适pH为 6— 8,对胰酶有抗性 ;不耐热 ,10 0℃下作用 1min ,其毒性完全消失 ,而在 5 6℃下 ,毒素完全失去活性需要 4 0min。     

Identifying potential breeding sites for the stone curlew (Burhinus oedicnemus) in the UK

The stone curlew (Burhinus oedicnemus) is one of the rarest breeding birds in the UK with an estimated breeding population of under 300 pairs. In the UK a marked decrease in the numbers has occurred, mainly due to habitat change or loss, resulting in the bird no longer breeding on many of its traditional nesting grounds. Using a Geographic Information System we define potential breeding areas in a landscape known to historically support a stone curlew breeding population. With an understanding of the birds’ abiotic nesting requirements, we model optimal locations for potential breeding sites for the bird, using known historical breeding data to verify the selection process. In total, we identify 424 parcels of land (2866 hectares) providing the critical habitat requirements for the stone curlew in the overall study area, 323 (1958 hectares) of which correspond with the known historic breeding distribution of the bird. We conclude that the modelling approach outlined is valuable in the identification of potential breeding sites for the stone curlew and that the model could be operated in tandem with agri-environment payments such as those offered within the Countryside Stewardship Scheme, in an attempt to focus these payments upon areas which will deliver maximum nature conservation potential. In addition we suggest that, subject to appropriate data availability, the approach outlined be applied to other species of high-conservation concern, particularly those which are currently under consideration for introduction or re-introduction programmes.