A relict trematosauroid (Amphibia: Temnospondyli) from the Middle Jurassic of the Junggar Basin (NW China)

A temnospondyl ilium from the uppermost Toutunhe Formation (Middle Jurassic, Callovian) of the southern Junggar Basin is described. Among the known temnospondyls it is very unusual in morphology because of its very long and slender shaft. It compares closely only to the ilium of one of the latest known trematosaurids from the Ladinian of southern Germany. The Toutunhe Formation has also yielded vertebrae and skull fragments of temnospondyls which belong to the brachyopid Gobiops from the Upper Jurassic of Mongolia. Brachyopoid ilia do not, however, display a morphology similar to that of the new specimen. It is therefore concluded that this specimen represents a second taxon of temnospondyl from the Toutunhe Formation, which probably represents the latest surviving trematosauroid. The Trematosauroidea, which was hitherto exclusively known from the Lower to early Upper Triassic, therefore joins the Brachyopoidea – and possibly the Capitosauroidea – as another group of temnospondyls which survived the end-Triassic mass extinction.     

A phylogenetic approach to the classification of the longidoridae (Nematoda: Dorylaimida)

A review is given of the main morphological characteristic of the Longidoridae, followed by the taxonomic history of the group and a critical evaluation of the genera. Only five genera are accepted and defined: Xiphinema; Xiphidorus; Paralongidorus; Longidoroides; Longidorus. Through out-group comparison and comparison of the five genera listed above, the characteristics of longidorid ancestry are established. The genera Enchodelus and Californidorus have been re-examined in the light of this comparison. Special attention has been given to the stylet guiding system in all forms considered. An attempt is made to assess the interrelationships of the different genera, and the resulting cladogram is used as a basis for a new classification of the family. Biogeography supports the phylogenetic scheme proposed.     

A mandible arresting system in neotropical social wasps (Vespidae; Polistinae): structural diversity within homogeneous functionality

Microtrichia are epidermal protuberances that may serve as temporary adhesive devices. Several insects possess these structures; however, they have not previously been reported in social wasps. With scanning electron microscopy, we characterize the shape and abundance of microtrichia in ten species of social wasps (Vespidae: Polistinae) and three species of related taxa (Vespidae: Eumeninae, Pompilidae, and Scoliidae). Semi-thin sections of the head of Leipomeles spilogastra and Apoica albimacula were also studied. We found microtrichia on a thin, flexible membrane connected to the mandible in all the Vespidae specimens. The flexible membrane can be divided into three regions: the basal region that covers the mandibular mesial emargination, the medial region located around the height of the mandibular condyles, and the distal region that appears anterior to the apodeme folding. Basal and distal regions of the membrane are extensively covered by microtrichia while the medial region has either less microtrichia or is entirely devoid of them. The shape and density of the microtrichia differed between species, and these traits are unrelated with nest material construction or phylogenetic closeness. We propose that the microtrichial membrane described is a passive mechanism to keep the wasps’ mandibles retracted through a mechanical interlocking system. It is possible that this energy-saving mechanism is present in other mandibulate insects.     

Prenatal identification of i(YP) by molecular cytogenetic analysis

An i(Yp) is a rare marker chromosome. We present a case of de novo 46,X,i(Yp) detected prenatally in an amniotic fluid specimen. Fluorescence in situ hybridization (FISH) studies using a panel of Y-specific biotinylated DNA probes identified the marker chromosome as i(Yp). Comparative genomic hybridization (CGH) studies further confirmed the diagnosis. Upon pregnancy termination, external examination of the fetus revealed a generally well-developed male fetus with slight facial dysmorphism and prominent rocker-bottom feet. The molecular cytogenetic data in this case proved very useful in genetic counselling and served as a good example illustrating the important role of molecular techniques for accurate identification of marker chromosomes.     

Torpor at high ambient temperature in a neotropical didelphid,the grey short-tailed opossum (Monodelphis domestica)

The grey short-tailed opossum, Monodelphis domestica, has been an established research animal for more than five decades, but relatively, little is known about its thermophysiology. Here we studied core body temperature (T _b) and metabolic rate (MR) of female adult M. domestica housed in the laboratory at an ambient temperature (T _a) of 26 °C. In expanding previous reports, the average recorded core T _b of M. domestica was 34.3 °C. The T _b of an individual M. domestica can drop below 30 °C (minimal T _b: 28.6 °C) accompanied by a reduction in MR of up to 52 % even while having ad libitum access to food. These findings demonstrate for the first time the presence of spontaneous torpor in M. domestica. Metabolic suppression at relatively high T _a and T _b furthermore broadens our perspective on the use of torpor as a metabolic strategy not just restricted to cold climates.     

New exocrine glands in ants: the hypostomal gland and basitarsal gland in the genus Melissotarsus (Hymenoptera: Formicidae)

Fisher and Robertson (Insect Soc 46: 78–83, 1999) discovered the production of silk-like secretions emerging from slit-shaped openings along the anterior margin of the ventral hypostoma of Melissotarsus ant workers. The current histological study describes a hitherto unknown hypostomal gland from which this silk-like substance originates. In addition, this study describes a new basitarsal gland in the three pairs of legs of Melissotarsus workers.     

Evolution through cold and deep waters: the molecular phylogeny of the Lithodidae (Crustacea: Decapoda)

The objectives of this work are to use gene sequence data to assess the hypothesis that the Lithodinae arose from ancestors with uncalcified abdomens in shallow waters of the North-East Pacific, investigate the monophyly and interrelationships of genera within the Lithodinae and to estimate the scale and minimum number of biogeographic transitions from the shallow environment to the deep sea and vice versa. To do this, phylogenetic analysis from three mitochondrial and three nuclear markers was conducted using minimum evolution, maximum likelihood and Bayesian methods. The Lithodinae as defined to include North Pacific genus Cryptolithodes may be paraphyletic, with the Hapalogastrinae and Cryptolithodes as sister taxa. This implies that the soft-bodied abdomen of the Hapalogastrinae might not be plesiomorphic for the Lithodidae. Paralomis, Lopholithodes, Phyllolithodes, Lithodes and Neolithodes share a common ancestor, from which the North Pacific Hapalogastrinae did not descend. Lithodid ancestors are likely to have had a north Pacific, shallow water distribution and to have had planktotrophic larvae. North Pacific genus Paralithodes is paraphyletic; P. brevipes is the most basal member of the genus (as sampled) while P. camtschaticus and P. platypus are more closely related to the genera Lithodes and Neolithodes. Genera Lithodes, Neolithodes and Paralomis (as sampled) are monophyletic if Glyptolithodes is included within Paralomis. Lopholithodes is closely related to, but not included within, the Paralomis genus. Paralomis is divided into at least two major lineages: one containing South Atlantic, West African, and Indian Ocean species, and the other containing Pacific and South American species. Several species of Paralomis do not resolve consistently with any other groups sampled, implying a complex and possibly rapid global evolution early in the history of the genus. Relationships within the Lithodes genus vary between analytical methods, suggesting that conclusions may not be stable. Consistently, however, Indian Ocean and Pacific forms—L. murrayi, L. longispina and L. nintokuae form a group separated from Atlantic species such as L. santolla, L. confundens, L. maja and L. ferox.     

The oldest micropepline beetle from Cretaceous Burmese amber and its phylogenetic implications (Coleoptera: Staphylinidae)

The staphylinid subfamily Micropeplinae includes small strongly sclerotized beetles with truncate elytra leaving the most part of abdomen exposed. Fossil micropeplines are rare and confined to Cenozoic representatives of extant genera. Here, we describe the oldest micropepline, Protopeplus cretaceus gen. and sp. n., from the Upper Cretaceous Burmese amber. Fluorescence microscope and confocal laser scanning microscopy (CLSM) were both used to reveal diagnostic features of Micropeplinae and some primitive traits that place Protopeplus very basally within Micropeplinae.     

细菌还原U(VI)分子生物学机理的研究进展

铀（U）污染对生态环境和人类健康的潜在危害受到越来越多的关注.U（VI）还原细菌可将U（VI）还原至U（IV）,从而降低铀在水中的溶解性和移动性,达到污染修复的目的.目前发现的U（VI）还原细菌主要包括但不限于铁还原菌和硫酸盐还原菌.本文综述了细菌还原U（VI）的分子生物学机理,重点阐述了U（VI）还原细菌的胞外电子转移方式,包括希瓦氏菌的金属还原方式、土杆菌的孔蛋白介导方式和微生物纳米线方式.竞争性电子受体和共存离子对细菌还原U（VI）有重要影响.目前细菌还原U（VI）过程中胞外电子转移的机理仍需更多实证,土杆菌利用微生物纳米线和细胞色素协作调控电子转移的机制尚不明确.今后可将研究聚焦于细菌还原U（VI）机理的验证和完善,并开发和优化基于微生物还原的铀污染修复技术,进而提高铀污染生物修复效率和稳定性.     

北极海洋沉积物石油降解菌的筛选及系统发育分析

从中国第二次北极科学考察采集的海洋沉积物中经富集培养、分离筛选得到了26株石油降解菌.研究表明,分离到的石油降解菌均可在以石油为唯一碳源和能源的无机营养盐培养基中生长,其中菌株P18、P28和P29生长最佳.当培养基中石油含量为2g·L-1时,于5℃下振荡培养14d,3株菌株的石油降解率可分别达到30.96%、34.85%和51.28%.分离到的石油降解菌绝大部分(25/26)能分泌胞外脂肪酶.表明其石油降解能力与产脂肪酶能力有着较强的相关性.分子鉴定与系统发育分析表明,分离到的石油降解菌除P31和P32属于细菌域(Bacteria)拟杆菌门(Bacteroidetes)的黄杆菌纲(Flavobacteria)外,其余均属于细菌域(Bacteria)变形杆菌门(Proteobacteria)的γ-变形杆菌纲(γ-Proteobacteria),其中包括交替单胞菌目(Aheromonadales)的假交替单胞菌属(Pseudoalteromonas)、科尔韦尔氏菌属(Colwellia)、希瓦氏菌属(Shetoanella),弧菌目(Vibrionales)的发光杆菌属(Photobacterium),假单胞菌目(Pscudomonadales)的假单胞菌属(Pseudomonas)和海螺菌目(Oceanospirillales)的盐单胞菌属(Halomonas).分离到的石油降解菌以假交替单胞菌属为优势菌群,其比例可达42%.     

Variety of technological trajectories in low emission vehicles (LEVs): A patent data analysis

This paper focuses on the diversity of engine technologies for low emission vehicles (LEVs) that are developed by car manufacturers in order to substitute for the conventional internal combustion engine vehicle (ICEV). Our purpose is to analyse the competition between the various technologies for LEVs as well as the innovative strategy of car manufacturers. We first propose to define and to represent these technological trajectories in order to compare their performances and to identify their strengths and weaknesses. The technological bottlenecks, the barriers to the adoption of these alternative engine technologies as well as the features of this technological competition are underlined. We then use a patent data analysis to study the patent portfolios of the main car manufacturers in these technologies over the period [1990–2005]. The dynamics of patent applications by car manufacturers gives insight on the competition among technologies and on the strategy of firms. This analysis emphasises the progressive diversification of firms' patent portfolios over the whole set of engine technologies and the differentiated strategic positioning of car manufacturers according to countries.     

Frugal cannibals: how consuming conspecific tissues can provide conditional benefits to wood frog tadpoles (Lithobates sylvaticus)

Tadpoles show considerable behavioral plasticity. When population densities become high, tadpoles often become cannibalistic, likely in response to intense competition. Conspecific tissues are potentially an ideal diet by composition and should greatly improve growth and development. However, the potential release of alarm cues from the tissues of injured conspecifics may act to deter potential cannibals from feeding. We conducted multiple feeding experiments to test the relative effects that a diet of conspecifics has on tadpole growth and development. Results indicate that while conspecific tissues represent a better alternative to starvation and provide some benefits over low-protein diets, such a diet can have detrimental effects to tadpole growth and/or development relative to diets of similar protein content. Additionally, tadpoles raised individually appear to avoid consuming conspecific tissues and may continue to do so until they suffer from the effects of starvation. However, tadpoles readily fed upon conspecific tissues immediately when raised with competitors. These results suggest that cannibalism may occur as a result of competition rather than the specific quality of available diets, unless such diets lead to starvation.     

Prenatal diagnosis of charcot-marie-tooth disease type 1a (CMT1A) using molecular genetic techniques

Charcot-Marie-Tooth disease type 1A (CMT1A) is a frequent hereditary motor and sensory neuropathy of the peripheral nerves. In most cases, the disease is associated with a 1.5 Mb tandem duplication at 17p11.2. A 42-year-old pregnant woman requested prenatal diagnosis because of her age and since both her husband and two children were severely affected with CMT1. The CMT1A duplication was demonstrated in the father's, the two children's, and the fetus's DNA using different molecular genetic methods. Although cytogenetical analysis showed a normal female karyotype in the fetus, the parents decided to terminate the pregnancy because of the genetic risk associated with the CMT1A duplication.     

Intrageneric differences in the four stereoisomers of stenusine in the rove beetle genus, Stenus (Coleoptera, Staphylinidae)

Most species of the rove beetle genus Stenus employ the spreading alkaloid stenusine as an escape mechanism on water surfaces. In the case of danger, they emit stenusine from their pygidial glands, and it propels them over the water very quickly. Stenusine is a chiral molecule with four stereoisomers: (2′R,3R)-, (2′S,3R)-, (2′S,3S)-, and (2′R,3S)-stenusine. The percentile ratio of these four isomers is only known for the most common species of the genus: Stenus comma. With the intention of determining the stereoisomer ratios of five additional species from the two subgenera, Stenus and Hypostenus, we used GC/mass spectrometry measurements with a chiral phase. The results showed that the ratio differs among the genus. These findings can be a basis for chemotaxonomy. It is also possible that the biological function of stenusine, e.g., as antibiotic or fungicide, varies with changing stereoisomer composition.