Prenatal sonographic appearance of foramina parietalia permagna

Foramina parietalia permagna (FPP) is an extremely uncommon congenital defect, inherited as an autosomal dominant condition. Its characteristics are two symmetrical orifices in the parietal bones (not of fixed size) on both sides of the midline. This defect does not affect either the psychic or the physical development of the affected person. This paper describes the sonographic appearance of FPP in utero as an enlargement of the posterior fontanelle.     

Developmental abnormalities in Glomeris marginata (Villers 1789) (Myriapoda: Diplopoda): implications for body axis determination in a myriapod

Abnormally developing embryos (ADEs) of the common pill millipede Glomeris marginata have been investigated by means of nuclear staining and mRNA in situ hybridization. It showed that all ADEs represent cases of Duplicitas posterior, which means that the posterior body pole is duplicated. The severity of the duplication ranges from duplicated posterior trunk segments in one specimen to an almost completely duplicated specimen that only shares the very anterior head region. Remarkably, none of the encountered ADEs represents a case of Duplicitas anterior (duplicated anterior pole) or a case of Duplicitas cruciata (cruciate duplication with two anterior and two posterior poles). This observation is discussed in the light of earlier reports on G. marginata ADEs that claim to have found these abnormalities. The lack of any other axial abnormality aside from D. posterior implies that early axis determination in G. marginata, and possibly myriapods in general, underlies the developmental mechanisms that prevent the formation of any other type of axial duplication. It is proposed that the formation of D. posterior-type embryos could be caused by the formation of two instead of only one posterior cumulus early during development.     

菹草乙酸乙酯组分抑藻活性物质的分离纯化和鉴定

前期研究表明,菹草乙酸乙酯组分能显著抑制赤潮微藻米氏凯伦藻的生长.在此基础上,采用硅胶柱层析和硅胶GF254薄层层析等方法,分离纯化菹草乙酸乙酯组分中的抑藻活性物质.进一步应用质谱、核磁共振碳谱和氢谱等技术,鉴定抑藻活性物质.结果表明,从菹草乙酸乙酯组分中分离纯化到2种抑藻活性物质.当浓度为16μg·m L-1时,它们对米氏凯伦藻表现出一定的抑藻活性.结构鉴定表明,此2种抑藻活性物质为Trichodermatides B和2-methylheptylisonicotinate.此2种化合物为首次从菹草中分离得到,也是首次从沉水植物中分离得到.     

A Middle Jurassic heterodontosaurid dinosaur from Patagonia and the evolution of heterodontosaurids

Heterodontosauridae is a morphologically divergent group of dinosaurs that has recently been interpreted as one of the most basal clades of Ornithischia. Heterodontosaurid remains were previously known from the Early Jurassic of southern Africa, but recent discoveries and studies have significantly increased the geographical and temporal range for this clade. Here, we report a new ornithischian dinosaur from the Middle Jurassic Ca?adón Asfalto Formation in central Patagonia, Argentina. This new taxon, Manidens condorensis gen. et sp. nov., includes well-preserved craniomandibular and postcranial remains and represents the only diagnostic ornithischian specimen yet discovered in the Jurassic of South America so far. Derived features of its anatomy indicate that Manidens belongs to Heterodontosauridae, as the sister taxon of Heterodontosaurus and other South African heterodontosaurids. The presence of posterior dentary teeth with high crowns but lacking extensive wear facets in Manidens suggests that this form represents an intermediate stage in the development of the remarkable adaptations to herbivory described for Heterodontosaurus. The dentition of Manidens condorensis also has autapomorphies, such as asymmetrically arranged denticles in posterior teeth and a mesially projected denticle in the posteriormost teeth. At an estimated total length of 60?C75?cm, Manidens furthermore confirms the small size of basal heterodontosaurids.     

Brainy stuff of long-gone dogs: a reappraisal of the supposed Canis endocranial cast from the Pliocene of Poland

The pre-Quaternary fossil record of Canis in the Old World is scarce, and the first appearance of this genus in Europe remains an enigma. Amongst the oldest fossils assigned to this genus, there is a natural cast of the brain (endocast) collected in W??e 1, Poland, from Pliocene deposits dated between 3.3 and 4.0 Ma. We reexamined this specimen and found that it differs from the brain of Canis in having its region medial to the coronal sulcus heart-shaped in dorsal view, its region rostral to the presylvian sulcus shorter and less constricted laterally, and its cerebellum less overlapped by the cerebrum and lacking a lateral twist of the posterior vermis. We identified this fossil, as well as another fossil canid endocast from W??e 1, as representing the raccoon dog genus Nyctereutes. The previously reported presence of Canis in W??e 1 is therefore not confirmed. Specifically, both endocasts can be referred to N. donnezani because this is the only species of Nyctereutes that has been recognised in this locality on the basis of craniomandibular and dental fossils. Our study represents a taxonomic application of comparative neuroanatomical and palaeoneurological data, an approach that may become increasingly useful with the growing knowledge of the endocranial morphology of fossil mammals.     

An exquisitely preserved troodontid theropod with new information on the palatal structure from the Upper Cretaceous of Mongolia

Troodontidae is a clade of small-bodied theropod dinosaurs. A new troodontid, Gobivenator mongoliensis gen. et sp. nov., is described based on the most complete skeleton of a Late Cretaceous member of this clade presently known, from the Campanian Djadokhta Formation in the central Gobi Desert. G. mongoliensis is different from other troodontids in possessing a pointed anterior end of the fused parietal and a fossa on the surangular in front of the posterior surangular foramen. The skull was superbly preserved in the specimen and provides detailed information of the entire configuration of the palate in Troodontidae. Overall morphology of the palate in Gobivenator resembles those of dromaeosaurids and Archaeopteryx, showing an apparent trend of elongation of the pterygoid process of the palatine and reduction of the pterygopalatine suture toward the basal Avialae. The palatal configuration suggests that the skull of Gobivenator would have been akinetic but had already acquired prerequisites for later evolution of cranial kinesis in birds, such as the loss of the epipterygoid and reduction in contact areas among bones.     

A new fossil thryonomyid from the Late Miocene of the United Arab Emirates and the origin of African cane rats

Cane rats (Thryonomyidae) are represented today by two species inhabiting sub-Saharan Africa. Their fossil record is predominately African, but includes several Miocene species from Arabia and continental Asia that represent dispersal events from Africa. For example, Paraulacodus indicus, known from the Miocene of Pakistan, is closely related to living Thryonomys. Here we describe a new thryonomyid, Protohummus dango, gen. et sp. nov., from the late Miocene Baynunah Formation of the United Arab Emirates. The new thryonomyid is less derived than “Thryonomys” asakomae from the latest Miocene of Ethiopia and clarifies the origin of crown Thryonomys and the evolutionary transition from Paraulacodus. A phylogenetic analysis shows Protohummus dango to be morphologically intermediate between Paraulacodus spp. and extinct and living Thryonomys spp. The morphological grade and phylogenetic position of Protohummus dango further supports previous biochronological estimates of the age of the Baynunah Formation (ca. 6–8 Ma).     

辽河下游CDOM吸收与荧光特性的季节变化研究

有色溶解有机物(CDOM)是一类广泛分布于水体中的溶解有机物(DOM),是水环境中最大的溶解有机碳贮库.辽河是中国七大河流之一,年径流量为14.8亿m3,因此对于辽河CDOM的研究对辽河有机碳通量的估算具有重要意义.基于吸收光谱和荧光光谱分析了不同季节辽河下游河流中CDOM的光学特性.通过分析CDOM的吸收光谱及斜率(S)得到春季水样CDOM在355 nm的吸收系数[aCDOM(355)]低于秋季和冬季;秋季CDOM的分子量要小于冬季和春季,而春季CDOM的分子量大于秋、冬季.通过对比分析3期荧光强度及各荧光峰(类腐殖酸荧光峰,峰A、峰C;类蛋白质荧光峰,峰B、峰T),发现辽河下游水体CDOM的荧光特性表现明显的季节性,而且都表现出较强的类蛋白质荧光峰(峰B和峰T).春季的两个类腐殖质荧光之间以及秋、冬季两个类蛋白质荧光之间均存在很强的相关性(R2>0.9),说明来源或性质相同.春季CDOM的两个类蛋白质荧光峰的相关性较差(R2=0.21),反映了其组分的复杂性和来源的多样性;春季水体显现出较强的类腐殖酸荧光峰,说明外源输入是春季水体CDOM中类腐殖酸成分的主要来源.另外,本研究将aCDOM(355)和Fn(355)进行分析发现冬季两者相关性最好(R2=0.75),秋季次之(R2=0.48),冬季结果较不理想(R2=0.01).通过荧光峰值与CDOM浓度之间的相关分析可以得到荧光峰B是秋、冬季CDOM荧光的主要控制发光基团(R=0.66;R=0.89),而春季CDOM的类腐殖酸荧光(峰A和峰C)表现比较突出(R=0.74;R=0.82).     

Contact toxicities of anuran skin alkaloids against the fire ant (Solenopsis invicta)

Nearly 500 alkaloids, representing over 20 structural classes, have been identified from the skin of neotropical poison frogs (Dendrobatidae). These cutaneous compounds, which are derived from arthropod prey of the frogs, generally are believed to deter predators. We tested the red imported fire ant (Solenopsis invicta) for toxicosis following contact with 20 alkaloids (12 structural classes) identified from dendrobatids or other anurans. Individual ants forced to contact the dried residues of 13 compounds exhibited convulsions and/or reduced ambulation. We estimated the cutaneous concentrations of several compounds based on their reported recoveries from skin extracts of free-ranging frogs and our measurements of the skin surface areas of museum specimens. Pumiliotoxin 251D exhibited contact toxicity below its estimated cutaneous concentration in the Ecuadorian frog, Epipedobates anthonyi, an observation consistent with the hypothesized role of this compound in anuran chemical defense. Our results and those of a previous study of mosquitoes indicate that some anuran skin compounds function defensively as contact toxins against arthropods, permeating their exoskeleton.     

A complex picture of associations between two host mussels and symbiotic bacteria in the Northeast Atlantic

Among chemosymbiotic metazoans found at deep-sea hydrothermal vents, cold seeps and organic falls, members of the mussel clade Bathymodiolinae (Bivalvia: Mytilidae) have evolved interactions with a higher diversity of bacterial lineages than other bivalve groups. Here, we characterized the bacteria associated with “Bathymodiolus” mauritanicus and Idas-like specimens from three sites in the Northeast Atlantic (two mud volcanoes in the Gulf of Cadiz and one seamount of the Gorringe Bank). Phylogenetic analysis of bacterial 16S rRNA-encoding gene sequences demonstrated that “B”. mauritanicus has a dual symbiosis dominated by two phylotypes of methane-oxidising bacteria and a less abundant phylotype of a sulphur-oxidising bacterium. The latter was the dominant phylotype in a sympatric population of Idas-like mussels at the Darwin mud volcano. These results are the first report of a bacterial phylotype shared between two deep-sea mussels from divergent clades. This sulphur-oxidising bacterium was absent from Idas-like specimens from the other two sites (Gorringe Bank and Meknès mud volcano), in which bacterial clone libraries were dominated by other Gammaproteobacteria related to symbionts previously identified in Idas modiolaeformis from the Eastern Mediterranean. All Idas-like specimens studied herein are closely related and also related to I. modiolaeformis. However, they probably display different associations with bacteria, with the possible absence of both methane- and sulphur-oxidising symbionts at the Gorringe Bank. These results draw a very complex picture of associations between mussels and bacteria in the Northeast Atlantic, which could be highly variable depending on locale characteristics of the habitats.     

Potential increase in mating frequency of queens in feral colonies of Bombus terrestris introduced into Japan

With the exception of several species, bumblebees are monandrous. We examined mating frequency in feral colonies of the introduced bumblebee Bombus terrestris in Japan. Using microsatellite markers, genotyping of sperm DNA stored in the spermatheca of nine queens detected multiple insemination paternities in one queen; the others were singly mated. The average effective paternity frequency estimated from the genotypes of queens and workers was 1.23; that estimated from the workers’ genotype alone was 2.12. These values were greater than those of laboratory-reared colonies in the native ranges of B. terrestris. The genotypes of one or two workers did not match those of their queens or showed paternities different from those of their nestmates; this may have arisen from either queen takeover or drifting of workers. These alien workers were responsible for the heterogeneous genotype distribution within each B. terrestris colony, resulting in higher estimates of paternity frequency than of insemination frequency. The high mating frequency of introduced B. terrestris may have occurred by artificial selection through mass breeding for commercialization. Moreover, polyandrous queens may be selectively advantageous, because reproduction by such queens is less likely to be disturbed by interspecific mating than that by monandrous queens.     

基于Landsat8影像估算新安江水库光合有效辐射漫射衰减系数

光合有效辐射(photosynthetically active radiation,PAR)是指可以被植物利用并进行光合作用的那部分太阳辐射,其进入湖水后受光学组分(悬浮颗粒、有色可溶性有机物和浮游植物)的吸收和散射作用发生衰减,对湖泊生物的密度和分布具有重要影响.本研究构建了基于Landsat 8影像数据的较为清洁的新安江水库PAR漫衰减系数的遥感估算模型,进而分析其时空分布特征及主要影响因素.结果表明,利用Landsat 8的第二、三和第八波段构建的多元回归模型能够得到较为准确的估算结果,模型决定系数为0.87.利用独立样本对构建的模型验证,预测值和实测值相对误差绝对值均值为9.16%,均方根误差为0.06 m~(-1),由此可见利用Landsat 8数据的3个波段,采用多元回归模型能够较好地估算较清洁水体的PAR漫射衰减系数.基于14景Landsat 8影像发现,新安江水库PAR漫射衰减系数季节差异性明显,秋季(9~11月)和夏季(6~8月)PAR漫射衰减系数较高,分别为(0.82±0.60)m~(-1)和(0.77±0.41)m~(-1),而冬季(12~次年2月)和春季(3~5月)PAR漫射衰减系数相对较低,分别为(0.56±0.50)m~(-1)和(0.40±0.45)m~(-1).新安江水库PAR漫射衰减系数空间差异性显著,全湖PAR漫射衰减系数变化范围为(0.002~13.86)m~(-1),均值为(0.64±0.49)m~(-1).漫射衰减系数的季节变化主要是由季节性降雨和浮游植物季节性生长引起,空间差异性主要由外源河流输入和部分水域采砂过程导致悬浮物浓度变化引起.     

Resource competition between two fungal parasites in subterranean termites

Subterranean termites live in large groups in underground nests where the pathogenic pressure of the soil environment has led to the evolution of a complex interaction among individual and social immune mechanisms in the colonies. However, groups of termites under stress can show increased susceptibility to opportunistic parasites. In this study, an isolate of Aspergillus nomius Kurtzman, Horn & Hessltine was obtained from a collapsed termite laboratory colony. We determined that it was primarily a saprophyte and, secondarily, a facultative parasite if the termite immunity is undergoing a form of stress. This was determined by stressing individuals of the Formosan subterranean termite Coptotermes formosanus Shiraki via a co-exposure to the virulent fungal parasite Metarhizium anisopliae (Metch.) Sorokin. We also examined the dynamics of a mixed infection of A. nomius and M. anisopliae in a single termite host. The virulent parasite M. anisopliae debilitated the termite immune system, but the facultative, fast growing parasite A. nomius dominated the mixed infection process. The resource utilization strategy of A. nomius during the infection resulted in successful conidia production, while the chance for M. anisopliae to complete its life cycle was reduced. Our results also suggest that the occurrence of opportunistic parasites such as A. nomius in collapsing termite laboratory colonies is the consequence of a previous stress, not the cause of the stress.     

Modification of actins by phallotoxins

Phallotoxins bind to filamentous actin (F-actin) from liver or rabbit muscle with K _diss～10^?8 M. By this combination the structure of F-actin is stabilized to such an extent that it will be resistant to the depolymerizing action of 0.6M KI and of deoxyribonuclease I, to denaturation by heat (70 °° C), and to local ruptures caused by ultrasonication or by cytochalasin B. The structural features of phallotoxins essential for affinity to F-actin are specific.     

泰乐菌素的微生物降解途径及其降解产物研究

研究了越南伯克霍尔德氏菌(Burkholderia vietnamiensis)对泰乐菌素的降解能力,并通过对降解产物的分析,推测了泰乐菌素的微生物降解途径.在自主筛选驯化分离到1株泰乐菌素高效降解菌B.vietnamiensis的基础上,采用高效液相色谱法测定其在不同条件下降解泰乐菌素的能力,并利用制备液相色谱分离纯化降解产物,质谱鉴定其结构.实验结果表明:B.vietnamiensis能高度耐受并快速降解泰乐菌素,用B.vietnamiensis处理初始浓度为50、100、200、300、400或500 mg·L-1的泰乐菌素培养基7 d,泰乐菌素的降解率均达到99%以上.B.vietnamiensis降解泰乐菌素的可能途径是:泰乐菌素A首先脱去碳霉糖转化为泰乐菌素B,然后分子中内酯键和醛基再经水解和还原生成2个新的降解产物.研究结果为泰乐菌素微生物降解机制的研究以及在此基础上降解酶的确定提供有价值的技术参考.     

Isolation, identification and characterization of an algicidal bacterium from Lake Taihu and preliminary studies on its algicidal compounds

In an effort to identify a bio-agent capable of controlling cyanobacterial blooms, we isolated a bacterial strain, A27, which exhibited strong algicidal activity against the dominant bloom-forming species of Microcystis aeruginosa in Lake Taihu. Based on 16S rRNA gene sequence analysis, this strain belongs to the genus Exiguobacterium. This is the first report of an algicidal bacterial strain belonging to the genus Exiguobacterium. Strain A27 exhibited algicidal activity against a broad range of cyanobacteria, but elicited little or no algicidal activity against the two green algal strains tested. The algicidal activity of strain A27 was shown to be dependent on the density of the bacteria and to have a threshold density of 1.5× 10⁶ CFU/mL. Our data also showed that the algicidal activity of strain A27 depended on different growth stages of Microcystis aeruginosa (exponential ≈ lag phase > early stationary) rather than that of the bacterium itself. Our results also suggested the algicidal activity of strain A27 occurred via the production of extracellular algicidal compounds. Investigation of the algicidal compounds revealed that there were at least two different algicidal compounds produced by strain A27. These results indicated that strain A27 has great potential for use in the control of outbreaks of cyanobacterial blooms in Lake Taihu.     

Isolation and Characterization of <Emphasis Type="Italic">Bacillus cereus</Emphasis> Bacteriophages from Foods and Soil

The aim of this study was to isolate and characterize Bacillus cereus bacteriophages of various origins. Twenty-seven bacteriophages against B. cereus were isolated from various Korean traditional fermented foods and soils. Plaque size, transmission electron microscopy, virulence profile, and in vitro lytic activity of bacteriophage isolates were examined. Transmission electron microscopy confirmed B. cereus bacteriophages belonging to the family Siphoviridae. Among B. cereus bacteriophages with broad host range, 18 isolates (66.7%) did not harbor any B. cereus virulence factors. Among them, bacteriophage strain CAU150036, CAU150038, CAU150058, CAU150064, CAU150065, and CAU150066 effectively inhibited B. cereus in vitro within 1 h. Therefore, they are considered potential candidates for controlling the contamination of B. cereus in food or other applications.     

Interspecific mating of the introduced bumblebee <Emphasis Type="Italic">Bombus terrestris</Emphasis> and the native Japanese bumblebee <Emphasis Type="Italic">Bombus hypocrita sapporoensis</Emphasis> results in inviable hybrids

The bumblebee Bombus terrestris is not only an effective pollinator, but also a potential invasive alien species outside its native range. Recently, nearly 30% of queens of the Japanese native species Bombus hypocrita sapporoensis and B. hypocrita hypocrita were estimated to copulate with B. terrestris males in the field, suggesting that indigenous bumblebees could be genetically deteriorated through hybrid production with the introduced species. In this study, we evaluated hybrid production between the introduced B. terrestris and the indigenous B. hypocrita sapporoensis under laboratory conditions. The hatching rate of eggs derived from interspecific matings was 0% and 8.6% depending on the direction of the cross, which was significantly lower than that from intraspecific matings of B. terrestris (76.9%) and B. hypocrita sapporoensis (78.9%). Genetic studies using microsatellite markers revealed that both haploid and diploid individuals were present in the egg stage, whereas all hatched larvae were haploid. In addition, histological studies revealed that eggs derived from interspecific matings terminated development 2 days after oviposition. These results strongly suggested that eggs derived from interspecific matings are inviable due to post-mating isolation mechanisms. Mass release of exotic pollinators could cause serious population declines of native bumblebee species.     

Indigenous bacteria may interfere with the biocontrol of plant diseases

Prodigiosin is a reddish antibiotic pigment that plays an important role in the biocontrol of plant diseases by the bacterium Serratia marcescens. However, its activity is unstable under agricultural conditions; further, it can be degraded by various environmental factors. To examine the effect of epiphytic microbes on the stability of prodigiosin used for biological control processes, we collected a total of 1,280 bacterial isolates from the phylloplane of cyclamen and tomato plants. Approximately 72% of the bacterial strains isolated from the cyclamen plants and 66% of those isolated from the tomato plants grew on minimal agar medium containing 100 μg ml⁻¹ prodigiosin. Certain isolates obtained from both plant species exhibited prodigiosin-degrading activity. We compared the 16S rRNA gene sequences derived from the isolates with sequences in a database. The comparison revealed that the sequences determined for the prodigiosin-degrading isolates were homologous to those of the genera Pseudomonas, Caulobacter, Rhizobium, Sphingomonas, Janthinobacterium, Novosphingobium, and Rathayibacter. These results indicate that indigenous epiphytic microorganisms may interfere with the interaction between plant pathogens and biocontrol agents by degrading the antibiotics produced by the agents.