Relationships of Fossil and Living Elasmobranchs

Preliminary cladistic analysis corroborates the hypothesis thatthe Elasmobranchii and the Holocephali are sister groups, andthat the Chondrichthyes are more closely related to the Teleostomi(Acanthodi plus Osteichthyes) than either is to the Placodermi.In regard to the Paleozoic and Mesozoic elasmobranchs, a theoryof relationships has been proposed for six better known genera(Xenacanthus, Denaea, Cladoselache, Hybodus, Ctenacanthus andPaleospinax) by evaluation of certain characters in the skull,postcranial axial skeleton, fin supports, and fins.     

Human chorionic gonadotropin beta-core fragment is directly produced by cancer cells

The present study was undertaken to investigate whether hCG beta-core fragment (hCGbeta cf) was directly produced by cancer cells. Fifteen cell lines, including four choriocarcinoma and five ovarian cancer cell lines, were tested, and immunoreactivity of hCGbeta cf was present in the culture media of five of the cell lines. It was also present in the culture media of Chinese hamster ovary (CHO) cells transfected with hCGbeta gene. In addition to hCGbeta cf, gel chromatography and Western blot analysis of the culture media showed the presence of an hCGbeta cf immunoreactive material with a molecular weight of approximately 40 kDa. In an in vivo study, hCGbeta cf immunoreactivity was detected in the sera of the mice transplanted with NaUCC-3 choriocarcinoma cells, although the ratios of hCGbeta cf/hCG and hCGbeta cf/free hCGbeta were lower than those in the culture medium. Incubation experiments of purified hCGbeta cf in the serum showed no substantial decrease in its values, ruling out the possibility that formation of a macromolecule with serum components may mask hCGbeta cf immunoreactivity in the serum. Taken together, these results indicate that hCGbeta cf immunoreactive materials are directly produced by cancer cells and hCGbeta cf is not a urinary metabolite of hCG or hCGbeta alone. Also, reduced levels of hCGbeta cf in the serum compared with that of intact hCG or free hCGbeta are likely due to its short half-life.     

西藏北部安多地区中侏罗统(巴通阶-卡洛夫阶)菊石

最近从藏北安多地区中侏罗统发现较丰富的菊石类化石,巴通期的菊石有OxyceritesoppeliElmi,Ho moeoplanulitescf. homoeomorphus(Buckman),H. cf. acuticosta(Roemer), Choffatiacf. vicentiMangold, Siemiradzkiacf. matisconensis(Lissajous), Proceritessp., Neuquenicerascf. yokoyamaiKobayashiandFukada和Indosphinctessp.。卡洛夫期的菊石有Oxyceritescf. subcotarius(Oppel), Macrocephalites? sp., Homoeoplanulitescf. furculus(Neumayr),Indospinctes(Elatmites) cf. reveliMangold和Reineckeitessp.。其中Indosphinctes,Indospinctes(Elatmites),Neu queniceras,Siemiradzkia和Procerites等属(或亚属)在西藏北部地区为首次报道。安多地区中—晚巴通期和早卡洛夫期菊石动物群凸现较强的地方性色彩; 晚巴通期ORBIS菊石带和早卡洛夫期KOENIGI菊石带是藏北地区菊石动物群扩散的重要时期。     

Cyanobacterial Microbiotic Crusts in Eroded Soils of a Tropical Dry Forest in the Baja California Peninsula,Mexico

This study deals with the cyanobacterial composition, and the nitrogen fixation of four members, of cryptobiotic crusts collected from eroded soils in a transitional area between arid and tropical climatic environments. Identification was based on microscopic analyses. Morphotypes were identified directly from reactivated natural crusts and from cultured strains. The identified morphotypes were Scytonema cf. ocellatum, Scytonema sp., Microcoleus cf. paludosus, M. cf. sociatus, Calothrix cf. elenkinii, C. cf. marchica, Nostoc cf. microscopicum, and Phormidium sp. Results show that the cyanobacterial composition of the microbiotic crusts studied is different from those in warmer and cooler deserts, particularly the absence of Microcoleus cf. vaginatus and Nostoc cf. commune in our samples. Such differences could be caused by the transitional character of the area. The results of the acetylene reduction assay show that the capacity of nitrogen fixation of some morphotypes is limited to the heterocyst-forming morphotypes.     

海藻糖降解酶抑制因子的研究

研究了一系列因素对食尼古丁节杆菌D-97胞内海藻糖降解酵的抑制作用,发现有效霉素(井冈霉素)和乙酸能有效抑制海藻糖降解酶的活性,抑制率最大分别达到87．13％和85．16％．同时研究了它们对海藻糖转化率的影响,发现有效霉素能提高海藻糖转化率,最大增幅达17．44％,而乙酸却降低了转化率。     

Diet of Physalaemus cf. cicada (Leptodactylidae) and Bufo granulosus (Bufonidae) in a semideciduous forest.

We determined the diet of the two most abundant anuran species which occur in the litter of a semideciduous forest (Len?óis, Bahia, Brazil), Physalaemus cf. cicada and Bufo granulosus in the dry and rainy seasons. Pitfall traps were used to collect anuran and invertebrate fauna, which showed the availability of prey in the environment. Physalaemus cf. cicada was present in both seasons and Bufo granulosus only in the rainy season. Both species fed mainly on Isoptera and Formicidae. However, there is a difference between the rainy and dry seasons concerning the diet of P. cf. cicada. During the rainy season P. cf. cicada consumed less Isoptera and more Formicidae than in the dry season. In the volumetric sense, Orthoptera was the most important alimentary category for P. cf. cicada and B. granulosus. The Jacobs electivity index indicated that Physalaemus cf. cicada and Bufo granulosus were specialists in Isoptera.     

河南固始早石炭世杨山组植物群

系统描述了扬山组植物18属25种,其中以石松类及种子蕨和真蕨纲为主,仅少数属楔叶纲;石松类中发现不少叶座较小,叶痕相对较大的鳞木类植物,颇似华夏植物群中的鳞木类;首次报道了我国发现的古芦木孢囊穗.据对植物群综合分析,杨山组的时代为早石炭世中晚期.     

Reproduction and larval development of two sympatric Pseudopolydora species (Annelida: Spionidae) in Japan

Pseudopolydora cf. kempi and Pseudopolydora cf. reticulata, which are morphologically similar, are sympatric in Gamo Lagoon, near Sendai on the Pacific eastern coast of Honshu, Japan. Reproduction, larval development, and larval morphology of these two species were compared. The larval developmental pattern of P. cf. kempi was determined to be short-term planktonic with lecithotrophy and adelphophagy, whereas that of P. cf. reticulata was long-term planktonic with planktotrophy. The number of embryos per capsule differed between the two species: 0–16 for P. cf. kempi and 62–405 for P. cf. reticulata. Nurse eggs were only found for P. cf. kempi. The results of this study suggest that some previous studies attributed to P. kempi may have been to P. cf. reticulata or to another species in this complex.     

Investigation of toxin profile of Mediterranean and Atlantic strains of Ostreopsis cf. siamensis (Dinophyceae) by liquid chromatography–high resolution mass spectrometry

Blooms of Ostreopsis spp. once confined to tropical and subtropical areas have recently spread to more temperate regions such as the Mediterranean and the Southern-Atlantic coasts of Europe. However, while O. confronta (cf.) ovata has caused several toxic outbreaks, the presence of O. cf. siamensis has been reported rather occasionally and in very few regions; as a consequence, O. cf. ovata toxin profile has been in-depth studied while poor information exists on toxicity of the Mediterranean and Atlantic O. cf. siamensis. In the present study toxin profile of Mediterranean and Atlantic O. cf. siamensis isolates also phylogenetically related has been studied through liquid chromatography–high resolution mass spectrometry (LC–HRMS) versus a palytoxin standard, a crude extract of O. cf. ovata containing all the ovatoxins so far known (ovatoxin-a to -f), and a Japanese O. siamensis extract which contained ostreocin-d and ostreocin-b. The Mediterranean and Atlantic O. cf. siamensis strains were shown not to produce either ostreocins, which are produced by the Japanese O. siamensis strain, or ovatoxins, which are produced by the Mediterranean O. cf. ovata. Only sub-fg levels of palytoxin on a per cell basis were detected in the Mediterranean strain. This study demonstrates that the Mediterranean and the Atlantic O. cf. siamensis strains are devoid of any appreciable toxicity. Thus, at least in the European area, O. cf. siamensis seems to present a much lower risk to human health than O. cf. ovata.     

华南贵州早奥陶世红花园组的镰箭类牙形刺

本文描述了产自华南贵州下奥陶统红花园组(桐梓红花园标准剖面,沿河甘溪剖面和贵阳黄花冲剖面)的四个镰箭类牙形刺种:Drepanoistodus sp.cf.nowlani,Paltodus sp.cf.P.subaequalis,Paltodus sp.A和Paroisto-dus sp.。D.sp.cf.nowlani为红花园组常见种,但另三种则相对稀少。在红花园组标准剖面,Paltodus sp.cf.P.subaequalis最低出现于该组底部,证实此层位为晚特马豆克期。文中详细图示了产于瑞典下奥陶统的两个带化石种:Paltodus deltifer和Paroistodus proteus,以及瑞典镰箭刺属的三个常见种:Drepanoistodus forceps,D.basiovalis和D.sp.cf.D.suberectus。通过与瑞典材料的详细对比,我们认为华南以前关于P.proteus和P.deltifer两种的记述多有误,须重新厘定。     

贵州凯里生物群中软舌螺的初步研究

本文描述了采自贵州台江县革东镇八郎中寒武世凯里生物群中的软舌螺化石,计有1种,3相似种和1个未定种。即：Ambrolinevitus cf.ventricosus,Glossolites?sp..Haplophrentis?cf.carinatus,Linevitus opimus,Hyolithes?cf.cariniferus.凯里生物群中软舌螺特点是：1)壳体通常较大,呈宽锥形;2)背、腹壳区分明显,常具中槽或中脊;3)特别是以软舌螺目中的软舌螺科和线带螺科的软舌螺保存数量最多。完全与欧洲、北美相当层位中出现的软舌螺组合面貌相似;并与澄江动物群中的软舌螺在演化特征上是可衔接的。凯里生物群中的软舌螺除具有世界性属种外。还具地区特有的属种。这对研究软舌螺的地理分布、演化进程以及与凯里生物群组合关系有重要意义。     

The effect of daily exposure to low hardening temperature on plant vital activity

Phenomenological responses of plants to daily short-term exposure to low hardening temperature was studied under chamber and field conditions. Experiments were carried out on cucumber (Cucumis sativus L.), barley (Hordeum vulgare L.), marigolds (Tagetes L.), and petunia (Petunia × hybrida) plants. The obtained data demonstrated a similar pattern of response in all studied plant species to different variants of exposure to low hardening temperature. The main features of plant response to daily short-term exposure to low hardening temperature include: a higher increment in cold tolerance (cf. two-or threefold increase relative to constant low hardening temperature) that peaked on day 5 (cf. day 2 at constant low hardening temperature) and was maintained for 2 weeks (cf. 3–4 days at constant low hardening temperature); a simultaneous increase in heat tolerance (cf. twofold relative to constant low hardening temperature) maintained over a long period (cf. only in the beginning of the exposure to constant low hardening temperature); a sharp drop in the subsequent cold tolerance after plant incubation in the dark (cf. a very low decrease in cold tolerance following the exposure to constant low hardening temperature); a combination of high cold tolerance and high photochemical activity of the photosynthetic apparatus (cf. a low non-photochemical quenching at constant low hardening temperature); and the capacity to increase cold tolerance in response to repeated short-term exposures to low hardening temperature in plants grown outdoors (cf. a gradual increase after repeated exposure to constant low hardening temperature). Possible mechanisms underlying the plant response to daily short-term exposure to low temperature are proposed.     

Some osteological differences between the blennioid fishes Limnichthys polyactis and L. rendahli,with comments on other species of Creediidae

Abstract

The two endemic species of New Zealand Limnichthys differ in several osteological characters. L. polyactis differs from L. rendahli in having a rayed dorsal margin of the opercle (cf. entire), little or no gap between the lower limb of the coracoid and the pelvis (cf. wide gap), one epural (cf. two), and narrow posterior neural and haemal spines (cf. wide spines). Comments are given on some characters in the other 10 recognised named species of Creediidae. Squamicreedia obtusa is removed from the Creediidae, and is provisionally placed in the Percophididae.     

Reproductive biology of several species of recently collected pelagic nemerteans

The reproductive biology and morphology of six polystiliferous and onemonostiliferous species of pelagic nemerteans was studied in specimensrecently collected off California. Depth distributions for these specimensranged from 250 m to 3250 m, with most specimens obtained between 700 m and1750 m. Length of sexually mature individuals ranged from 2 mm for themonostiliferan to 61 mm for a male Phallonemertes cf. murrayi. Among P. cf.murrayi and Nectonemertes cf. mirabilis, which yielded the largest specimensstudied, mature males were larger than mature females and mature animalswere larger than those in which gonads were not apparent. Females typicallyoutnumbered males, although N. cf. mirabilis approached a 1:1 sex ratio. Inthe polystiliferans studied by light microscopy, accessory ovarian cellsappeared to translocate yolk or yolk precursors to oocytes via cytoplasmicbridges, a mechanism typically associated with nurse cells and notpreviously reported from nemerteans. Mature oocytes 0.5–1 mm indiameter were common, making them very large compared to those of benthicnemerteans. Sperm possessed elongated heads and nuclei. In general, thepelagic nemerteans studied appeared: a) to produce relatively few maturegametes at a time, b) spawn in close proximity to each other, c) undergoiteroparous reproduction, and d) display moderately long-lived life cycles.In addition, data for P. cf. murrayi and possibly N. cf. mirabilisdemonstrates potential seasonal peaks in reproductive activity.     

Ostreopsis cf. ovata in the Gulf of Gabès (south-eastern Mediterranean Sea): morphological,molecular and ecological characterization

In the last few decades, the frequency of the toxic benthic dinoflagellate Ostreopsis cf. ovata proliferation has increased in the Mediterranean Sea. These blooms are associated with harmful effects on human health and the environment. The present work provides the first long term study on the spatio-temporal distribution of O. cf. ovata in relation to physical parameters in the Gulf of Gabès coastal waters (south-eastern Mediterranean Sea), as well as its morphological, molecular and physiological features. The strains of O. cf. ovata were identified morphologically by light and epifluorescence microscopy. The morphology and the size range of cultured strains were similar to those described regarding O. cf. ovata isolated from the Mediterranean Sea. The ultrastructural analysis of O. cf. ovata cells using the transmission electron microscopy showed the presence of numerous vesicles (VE) containing spirally coiled fibers (SCFs) connected to the mucus canal (CH). The phylogenetic tree based on the internal transcribed spacer region containing the 5.8S rDNA (ITS-5.8S rDNA) revealed that O. cf. ovata strains were placed into the Mediterranean/Atlantic clade. In addition, O. cf. ovata toxicity was evaluated by the mouse bioassay and a dose level ≥ 4 × 10⁴ cells was found to be lethal to mice. The examination of the O. cf. ovata occurrence in the Gulf of Gabès at a large temporal scale (1997–2012) revealed a clear seasonal pattern with dominance from midsummer (July) to late autumn (November). Furthermore, a positive correlation was found between the abundance of O. cf. ovata and salinity, whereas no correlation was found as regards temperature. The occurrence of O. cf. ovata was only detected at salinity above 35 and the highest concentrations were observed at 45. Laboratory experiments confirmed such a result and showed that isolated O. cf. ovata strains had optimal growth at salinity ranging between 35 and 45, with its peak at 40.     

苏北盆地阜宁组钙质超微化石由来初探

对苏北盆地4个钻孔300余块心样品进行了分析,在阜宁组的8块样品中发现了钙质超微化石,计3属1种及3个比较种,化石属种单调,保存较 ,受到严重的溶蚀或增生,结合这些种类的分布时代和产出层位,很难排除苏北盆地阜宁组钙质超微化石再沉积的属性。     

Genetic analyses of cell death in maize (Zea mays, Poaceae) leaves reveal a distinct pathway operating in the camouflage1 mutant

Controlled cell death is vital for many physiological processes in plants, such as xylem development, the hypersensitive response (HR), and senescence; however, the pathways governing cell death are incompletely understood. Studies of mutants that display a cell-death phenotype have greatly contributed to our knowledge of how this process is regulated. The maize camouflage1 (cf1) mutant displays the novel phenotype of cell-specific death of bundle sheath (BS) cells in discrete yellow leaf tissues. To investigate the BS cell death in cf1 mutants, we characterized potential underlying factors. Hydrogen peroxide (H(2)O(2)) is known to be involved in many cell-death events in plants, including the HR. However, in vivo staining found no accumulation of H(2)O(2) in cf1 mutant leaves. Additionally, genetic analyses determined that functional chloroplasts are required for cf1 BS cell death. These results demonstrate that cf1 BS cell death occurs via a distinct pathway from that seen in a functionally related maize mutant or in the HR, suggesting that cell death in maize leaves can be caused by multiple mechanisms.