Sample records for especies nuevas mollusca

  1. Nuevas tecnolog韆s y educaci髇 especial

    Microsoft Academic Search

    Inmaculada Bernardo; Ana Bernardo; Javier Herrero

    El auge de las nuevas tecnolog韆s supuso un camino alternativo a la intervenci髇 tradicional en las Di- ficultades de Aprendizaje. No obstante, si tenemos en cuenta que un porcentaje significativo de las Di- ficultades de Aprendizaje son inespec韋icas, es decir, de etiolog韆 y sintomatolog韆 diversificada, no se- r韆 de extra馻r que los programas informatizados dirigidos a las diferentes capacidades deficitarias,

  2. Hyphessobrycon ocasoensis sp. n. (Teleostei, Characidae) una nueva especie para el Alto Cauca, Colombia

    Microsoft Academic Search

    C. A. Garc韆-Alzate; C. Rom醤-Valencia

    2009-01-01

    Se describe Hyphessobrycon ocasoensis sp. n. (Characiformes, Characidae) perteneciente al grupo heterorhabdus (Gery, 1977) de la cuenca alta del r韔 Cauca, Colombia. La nueva especie se distingue de las otras especies descritas por la siguiente combinaci髇 de caracteres: tres radios simples y ocho radios ramificados en la aleta dorsal; un maxilar corto con un diente o sin dientes; cuatro peque駉s

  3. Protostomia: Lophotrochozoa: Mollusca Protostomia: Lophotrochozoa: Mollusca

    E-print Network

    carbonate shells 颅 lost or reduced in some 路 Heart and open circulatory system #12;Mollusca Protostomia 路 Calcium carbonate shells 颅 lost or reduced in some 路 Heart and open circulatory system 颅 hemocoel #12 or reduced in some 路 Heart and open circulatory system 颅 hemocoel 路 3 main body parts: foot, visceral mass

  4. Overwinteringsgedrag van de nauwe korfslak Vertigo angustior (Mollusca)

    Microsoft Academic Search

    A. Boesveld

    2005-01-01

    Overwintering habits of the land snail Vertigo angustior (Mollusca) During a mollusc survey in 2004 en 2005 in the province of Zuid-Holland special attention was paid to Vertigo angustior. The species was observed overwintering in large groups, up to hundreds of specimens together, between mosses (especially Brachythecium rutabulum (Hedw.) Schimp.) in small patches of poplar forest (Populus nigra and Populus

  5. Phylogenetic relationships among Opisthobranchia (Mollusca: Gastropoda) based on mitochondrial

    E-print Network

    Zardoya, Rafael

    Phylogenetic relationships among Opisthobranchia (Mollusca: Gastropoda) based on mitochondrial cox relationships among 37 species representing seven main lineages within Opisthobranchia (Mollusca: Gastropoda

  6. OPISTHOBRANCHIATE MOLLUSCA FROM MONTEREY BAY, CALIFORNIA, AND VICINITY.

    E-print Network

    OPISTHOBRANCHIATE MOLLUSCA FROM MONTEREY BAY, CALIFORNIA, AND VICINITY. By F. M. MACFARLAND for pagination #12;OPISTHOBRANCHIATE MOLLUSCA FROM MONTEREY BAY, CALIFORNIA, AND VICINITY. By F. M. MACFARLAND. For the identification of even the genera to which many of the nudibranchiate . mollusca belong, it is necessary to make

  7. Book Review Phylogeny and Evolution of the Mollusca

    E-print Network

    Zuschin, Martin

    Book Review Phylogeny and Evolution of the Mollusca Ponder, W.F. & Lindberg, D.R. (Eds) University of California Press, Berkeley, 2008; 469 pp. ISBN 978-0- 520-25092-5. Hardback, $49.95. Mollusca are the most on the relationships among the mollus- can classes discusses the ongoing debate on the sister group to the Mollusca

  8. Ciliary ultrastructure of polyplacophorans (Mollusca, Amphineura, Polyplacophora).

    PubMed

    Lundin, K; Schander, C

    2001-01-01

    This study is part of a series of papers aiming to investigate the phylogenetic significance of ciliary ultrastructure among molluscs and to test the hypothesis of a relationship between Xenoturbella and the molluscs. The ultrastructure of the ciliary apparatus on the gills of the polyplacophorans Leptochiton asellus and Tonicella rubra was studied. The gill cilia of the two species are similar in shape. The free part of the cilium is long with a slender distal part. There are two ciliary rootlets. One of them is short, broad and placed on the anterior face of the basal body. The other rootlet is conical and has a vertical orientation. Among the mollusca, two ciliary rootlets in the ciliary apparatus of multiciliate ectodermal cells have only been reported from the Chaetodermomorpha and Neomeniomorpha. This character state is likely plesiomorphic for the Mollusca and indicates a basal (nonderived) position of these taxa among the molluscs. No possible synapomorphic character with Xenoturbella bocki was found. PMID:11686414

  9. Biodiversity among luminescent symbionts from squid of the genera Uroteuthis, Loliolus and Euprymna (Mollusca: Cephalopoda)

    E-print Network

    Nishiguchi, Michele

    (Mollusca: Cephalopoda) R. C. Guerrero-Ferreira and M. K. Nishiguchi* Department of Biology, New Mexico Society 2007. Members of the families Loliginidae and Sepiolidae (Mollusca: Cephalopoda) have been

  10. Octopus tetricus (Mollusca: Cephalopoda) as an ecosystem engineer

    E-print Network

    Scheel, David

    Octopus tetricus (Mollusca: Cephalopoda) as an ecosystem engineer David Scheel 1, Peter Godfrey octopus (Octopus tetricus) occurs in unusual numbers on a shell bed of its prey remains that have accumulated as an extended midden where additional octopuses excavate dens. Here, O tetricus are ecosystem

  11. ESPECIE NUEVA DE SANGUIJUELA DEL G蒒ERO HELOBDELLA (RHYNCHOBDELLIDA: GLOSSIPHONIIDAE) DEL LAGO DE CATEMACO, VERACRUZ, M蒟ICO

    Microsoft Academic Search

    Alejandro OCEGUERA-FIGUEROA

    2007-01-01

    A new leech species of the genus Helobdella from Catemaco Lake, Veracruz, Mexico is described based on the examination of 23 specimens. Leeches were found attached to submerged rocks and plants. The new species lacks a nuchal scute and is distinguishable from other species of the genus by the presence of a obscure dorsal surface with white spots of different

  12. Una especie nueva de Epicauta (Coleoptera: Meloidae) del Plioceno del Estado de Hidalgo, M閤ico

    Microsoft Academic Search

    Santiago Zaragoza-Caballero; Patricia Velasco-de Le髇

    2003-01-01

    An impression of Epicauta Dejean is described and illustrated from the Atotonilco El Grande Formation of Pliocene age, located in the State of Hidalgo, M閤ico. The specimen is compared with E. subneglecta Wickham from the Florissant Formation (Eocene) in Colorado, USA, and with Epicauta sp. from Lake Rita Blanca (early Pleistocene) in Texas, USA.

  13. All the three ParaHox genes are present in Nuttallochiton mirandus (Mollusca: polyplacophora): evolutionary considerations.

    PubMed

    Barucca, Marco; Biscotti, Maria A; Olmo, Ettore; Canapa, Adriana

    2006-03-15

    The ParaHox gene cluster contains three homeobox genes, Gsx, Xlox and Cdx and has been demonstrated to be an evolutionary sister of the Hox gene cluster. Among deuterostomes the three genes are found in the majority of taxa, whereas among protostomes they have so far been isolated only in the phylum Sipuncula. We report the partial sequences of all three ParaHox genes in the polyplacophoran Nuttallochiton mirandus, the first species of the phylum Mollusca where all ParaHox genes have been isolated. This finding has phylogenetic implications for the phylum Mollusca and for its relationships with the other lophotrochozoan taxa. PMID:16331637

  14. The Complete Mitochondrial Genome of Galba pervia (Gastropoda: Mollusca), an Intermediate Host Snail of Fasciola spp

    PubMed Central

    Huang, Wei-Yi; Zhao, Guang-Hui; Wei, Shu-Jun; Song, Hui-Qun; Xu, Min-Jun; Lin, Rui-Qing; Zhou, Dong-Hui; Zhu, Xing-Quan

    2012-01-01

    Complete mitochondrial (mt) genomes and the gene rearrangements are increasingly used as molecular markers for investigating phylogenetic relationships. Contributing to the complete mt genomes of Gastropoda, especially Pulmonata, we determined the mt genome of the freshwater snail Galba pervia, which is an important intermediate host for Fasciola spp. in China. The complete mt genome of G. pervia is 13,768 bp in length. Its genome is circular, and consists of 37 genes, including 13 genes for proteins, 2 genes for rRNA, 22 genes for tRNA. The mt gene order of G. pervia showed novel arrangement (tRNA-His, tRNA-Gly and tRNA-Tyr change positions and directions) when compared with mt genomes of Pulmonata species sequenced to date, indicating divergence among different species within the Pulmonata. A total of 3655 amino acids were deduced to encode 13 protein genes. The most frequently used amino acid is Leu (15.05%), followed by Phe (11.24%), Ser (10.76%) and IIe (8.346%). Phylogenetic analyses using the concatenated amino acid sequences of the 13 protein-coding genes, with three different computational algorithms (maximum parsimony, maximum likelihood and Bayesian analysis), all revealed that the families Lymnaeidae and Planorbidae are closely related two snail families, consistent with previous classifications based on morphological and molecular studies. The complete mt genome sequence of G. pervia showed a novel gene arrangement and it represents the first sequenced high quality mt genome of the family Lymnaeidae. These novel mtDNA data provide additional genetic markers for studying the epidemiology, population genetics and phylogeographics of freshwater snails, as well as for understanding interplay between the intermediate snail hosts and the intra-mollusca stages of Fasciola spp.. PMID:22844544

  15. Distribution and zoogeographical characteristics of mollusks (Mollusca) from Bulgarian national parks

    Microsoft Academic Search

    Zdravko HUBENOV

    HUBENOV Z. 2007. Distribution and zoogeographical characteristics of mollusks (Mollusca) from Bulgarian national parks. - Historia naturalis bulgarica, 18: 127-159. Abstract. A total of 132 species of mollusks have been reported from Bulgarian National Parks. They belong to 72 genera, 31 families and 4 orders of the classes Gastropoda and Bivalvia. The largest number of species have been established in

  16. Marine Mollusca of the last 2 million years in New Zealand. Part 5. Summary

    Microsoft Academic Search

    AG Beu

    2012-01-01

    Evolution occurred equally through allopatric speciation and anagenesis during Pliocene朎arly Pleistocene time. However, no anagenesis is observed in Castlecliffian to Recent Mollusca. Possible explanations include (1) increasing shallowness and energy of the environment (Sheldon's 憄lus 鏰 change model); (2) lecithotrophs increased with falling temperatures, and are more susceptible than planktotrophs to allopatric speciation; (3) 憄lus 鏰 change implies that anagenesis

  17. Descriptions of three new species of Mitridae (Mollusca: Gastropoda) from South China Sea

    NASA Astrophysics Data System (ADS)

    Li, Baoquan; Zhang, Suping; Li, Xinzheng

    2005-03-01

    Three new species of Family Mitridae (Mollusca: Gastropoda) from the South China Sea are described in the present paper. They are Ziba aglais sp. nov. B. LI & S. ZHANg, Neocancilla daidaleosa sp. nov. B. LI & X. LI, and Mitra holkosa sp. nov. B. LI. Their systematic positions are also discussed.

  18. On the biology and palaeontology of some predators of bivalved mollusca

    Microsoft Academic Search

    R. M. CARTER

    1968-01-01

    SUMMARY A summary is given of the feeding habits of known predators on bivalve molluscs, including birds, fish, Pinnipedia, Mollusca, Arthropoda and Asterozoa. The fossil record of these groups, and of other possible extinct predators, is discussed in relation to the fossil record of the bivalves. It is concluded that asteroids are, and were, probably the most important of all

  19. Comparative genomics of vesicomyid clam (Bivalvia: Mollusca) chemosynthetic symbionts

    PubMed Central

    Newton, Irene LG; Girguis, Peter R; Cavanaugh, Colleen M

    2008-01-01

    Background The Vesicomyidae (Bivalvia: Mollusca) are a family of clams that form symbioses with chemosynthetic gamma-proteobacteria. They exist in environments such as hydrothermal vents and cold seeps and have a reduced gut and feeding groove, indicating a large dependence on their endosymbionts for nutrition. Recently, two vesicomyid symbiont genomes were sequenced, illuminating the possible nutritional contributions of the symbiont to the host and making genome-wide evolutionary analyses possible. Results To examine the genomic evolution of the vesicomyid symbionts, a comparative genomics framework, including the existing genomic data combined with heterologous microarray hybridization results, was used to analyze conserved gene content in four vesicomyid symbiont genomes. These four symbionts were chosen to include a broad phylogenetic sampling of the vesicomyid symbionts and represent distinct chemosynthetic environments: cold seeps and hydrothermal vents. Conclusion The results of this comparative genomics analysis emphasize the importance of the symbionts' chemoautotrophic metabolism within their hosts. The fact that these symbionts appear to be metabolically capable autotrophs underscores the extent to which the host depends on them for nutrition and reveals the key to invertebrate colonization of these challenging environments. PMID:19055818

  20. Bioactive substances with anti-neoplastic efficacy from marine invertebrates: Bryozoa, Mollusca, Echinodermata and Urochordata.

    PubMed

    Sima, Peter; Vetvicka, Vaclav

    2011-11-10

    The marine environment provides a rich source of natural products with potential therapeutic application. This has resulted in an increased rate of pharmaceutical agents being discovered in marine animals, particularly invertebrates. Our objective is to summarize the most promising compounds which have the best potential and may lead to use in clinical practice, show their biological activities and highlight the compounds currently being tested in clinical trials. In this paper, we focused on Bryozoa, Mollusca, Echinodermata and Urochordata. PMID:22087434

  1. Serotonin-and FMRFamide-immunoreactive nerve elements in the chiton Lepidopleurus asellus (Mollusca, Polyplacophora)

    Microsoft Academic Search

    Leonid Moroz; Leonid Nezlin; Rolf Elofsson; Dmitri Sakharov

    1994-01-01

    The distribution of serotonin-like and FMRFamide-like immunoreactive (5HT-ir and FMRFa-ir, respectively) neurons in the nervous system of the chiton Lepidopleurus asellus (Mollusca, Polyplacophora) was studied using an immunocytochemical technique. The neurons were distributed in characteristic patterns in the central nervous system, the 5HT-ir neurons predominating in the ventral (pedal) cords and FMRFa-ir neurons in the lateral cords. In the body

  2. Neuromuscular development of Aeolidiella stephanieae Vald閦, 2005 (Mollusca, Gastropoda, Nudibranchia)

    PubMed Central

    2010-01-01

    Background Studies on the development of the nervous system and the musculature of invertebrates have become more sophisticated and numerous within the last decade and have proven to provide new insights into the evolutionary history of organisms. In order to provide new morphogenetic data on opisthobranch gastropods we investigated the neuromuscular development in the nudibranch Aeolidiella stephanieae Vald閦, 2005 using immunocytochemistry as well as F-actin labelling in conjunction with confocal laser scanning microscopy (cLSM). Results The ontogenetic development of Aeolidiella stephanieae can be subdivided into 8 stages, each recognisable by characteristic morphological and behavioural features as well as specific characters of the nervous system and the muscular system, respectively. The larval nervous system of A. stephanieae includes an apical organ, developing central ganglia, and peripheral neurons associated with the velum, foot and posterior, visceral part of the larva. The first serotonergic and FMRFamidergic neural structures appear in the apical organ that exhibits an array of three sensory, flask-shaped and two non-sensory, round neurons, which altogether disappear prior to metamorphosis. The postmetamorphic central nervous system (CNS) becomes concentrated, and the rhinophoral ganglia develop together with the anlage of the future rhinophores whereas oral tentacle ganglia are not found. The myogenesis in A. stephanieae begins with the larval retractor muscle followed by the accessory larval retractor muscle, the velar or prototroch muscles and the pedal retractors that all together degenerate during metamorphosis, and the adult muscle complex forms de novo. Conclusions Aeolidiella stephanieae comprises features of the larval and postmetamorphic nervous as well as muscular system that represent the ground plan of the Mollusca or even the Trochozoa (e. g. presence of the prototrochal or velar muscle ring). On the one hand, A. stephanieae shows some features shared by all nudibranchs like the postmetamorphic condensation of the CNS, the possession of rhinophoral ganglia and the lack of oral tentacle ganglia as well as the de novo formation of the adult muscle complex. On the other hand, the structure and arrangement of the serotonergic apical organ is similar to other caenogastropod and opisthobranch gastropods supporting their sister group relationship. PMID:20205753

  3. Oceanography Camp Especially for Girls

    E-print Network

    Meyers, Steven D.

    Oceanography Camp Especially for Girls Application for Admission All information is confidential Security Number: Date of Birth: Age: High school you plan to attend: email School you attend now: Grade... When I do sports I feel... When I do math I feel... A girl has a right to... A girl should always

  4. The Politics of Rural School Reform: Escuela Nueva in Colombia.

    ERIC Educational Resources Information Center

    McEwan, Patrick J.; Benveniste, Luis

    2001-01-01

    Traces evolution of rural-school education plan in Colombia (Escuela Nueva), focusing on importance of Colombia's changing political and social climate in policy development. Identifies three phases of reform development and implementation: grassroots, formalized, and decoupled. Uses Escuela Nueva to demonstrate importance of recognizing dynamic,

  5. Deroceras laeve M黮l. (Mollusca: Limacidae), ein Eir鋟ber von Pegomyia betae Curt. (Muscidae)

    Microsoft Academic Search

    U. R鰐tger; F. Klingauf

    1976-01-01

    Observations on the predacious activity of\\u000aDeroceras laeve M黮l. (Mollusca: Limacidae)on eggs of\\u000aPegomyia betae Curt.(Muscidae) and\\u000aEpilachna varivestis Muls.(Coccinellidae).\\u000aDeroceras laeve was observed feeding on eggs ofPegomyia betae in the laboratory and in the field. Since little is known about predacious behaviour of species of Limacidae, tests were conducted on the food preferences in two sets of experiments: (1)

  6. The mitochondrial genome of the sipunculid Phascolopsis gouldii supports its association with Annelida rather than Mollusca

    SciTech Connect

    Boore, Jeffrey L.; Staton, Joseph

    2001-09-01

    We have determined the sequence of about half (7470 nts) of the mitochondrial genome of the sipunculid Phascolopsis gouldii, the first representative of this phylum to be so studied. All of the 19 identified genes are transcribed from the same DNA strand. The arrangement of these genes is remarkably similar to that of the oligochaete annelid Lumbricus terrestris. Comparison of both the inferred amino acid sequences and the gene arrangements of a variety of diverse metazoan taxa reveals that the phylum Sipuncula is more closely related to Annelida than to Mollusca. This requires reinterpretation of the homology of several embryological features and of patterns of animal body plan evolution.

  7. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-05-01

    Secondary School Feature Articles * An Elementary Outreach Program-Have Demo Will Travel, by James Swim, p 628 * Pressure and Stoichiometry, by Charles E. Roser and Catherine L. McCluskey, p 638 Making Connections vs Relevance: Chemistry and Biology For many years there has been a movement to make chemistry more relevant to learners, particularly in introductory chemistry courses. Sidebars describing chemical applications to real-world settings are sprinkled throughout textbooks. Consumer products are often used in place of reagent-grade chemicals, not only as a means of cost saving, but also in an attempt to make chemistry more relevant for the beginning learner. The Journal has published many articles dealing with the application of chemistry to other disciplines. As our understanding of the importance of constructivism in intellectual development has increased, the need to help students make connections between the knowledge they have constructed and their experiences in the classroom and laboratory has become more evident. The need is much deeper than simply recognizing familiar products or observing visible chemical changes. Relevance appears to be a helpful and perhaps necessary condition for learning, but it does not appear to be sufficient to ensure that connections are made between chemical concepts new to the learner and previously constructed knowledge. This month's JCE Classroom Activity "Soup or Salad? Investigating the Action of Enzymes in Fruit on Gelatin" (p 624A) is an example of an experiment that requires the student to use biological concepts to carry out a chemical investigation. The action of proteases from fresh or frozen pineapple and meat tenderizers on the proteins that provide the structure of gelatin is compared with the action of fruit that has been canned or heated in a microwave. Like other JCE Classroom Activities, references, additional information, and related activities are cited. The activity can be used in the classroom or assigned as a take-home activity. JCE Classroom Activity #15, "Liver and Onions: DNA Extraction from Animal and Plant Tissues" (p 400A, March 1999) also integrates chemical and biological concepts. The JCE Software videotape HIV-1 Protease: An Enzyme at Work is another useful resource. It can be used in any classroom where kinetics, catalysis, proteins, or enzymes are discussed. Information about JCE Software products can be found in recent issues of the Journal or by accessing JCE Online (http://jchemed.chem.wisc.edu). Because most high school students complete at least one year of biology before enrolling in chemistry, developing the connections between biology and chemistry can be especially productive. Connections between chemistry and biology often seem to be more real to students than do many of the phenomena we cite as applications. For example, students often are not able to make the connection between the excitation of electrons to produce electromagnetic radiation and anything that is personally relevant. The light given off by sodium or mercury vapor lights provides a common example of relating atomic emission to a useful process, but many students do not seem to find that particularly interesting. The need to make a connection between biology and chemistry becomes especially meaningful to students when the chemical change occurs within the human body. As an example, the interaction of emitted electromagnetic radiation with human cells to cause well-tanned skin seems more relevant to a greater number of students than the color of lights in a parking lot. This issue contains an article that describes a useful application of light to kill cancer cells through use of photosensitizers (p 592). The process of photodynamic therapy (PDT) provides another example that could help students make a connection between the emission of electromagnetic radiation and the challenge of killing cancer cells without harming healthy cells. Certainly this example is not a magic antidote to "why do we have to learn this stuff" and it doesn't directl

  8. A new species of Eritrachys (Hemiptera: Pentatomidae: Ochlerini) from Ecuador (Especie nueva de Eritrachys (Hemiptera: Pentatomidae: Ochlerini) de Ecuador

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new species of to the genus Eritrachys Ruckes, E. brailovskyi, collected in Ecuador, is described and illustrated. The male of E. bituberculata Ruckes is described and illustrated, with new records from Panama and Ecuador. A key to the species of the genus is provided....

  9. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2000-01-01

    Ideas and Resources in This Issue This issue contains a broad spectrum of topics of potential interest to high school teachers, including chemical safety, history, demonstrations, laboratory activities, electrochemistry, small group learning, and instructional software. In his report on articles published recently in The Science Teacher, Steve Long includes annotated references from that journal, and also from JCE, that provide timely and practical information (pp 21-22). The chemical significance of several anniversaries that will occur in the year 2000 are discussed in an article by Paul Schatz (pp 11-14). Scientists and inventors mentioned include Dumas, W鰄ler, Goodyear, Joliot-Curie, Krebs, Pauli, Kjeldahl, and Haworth. Several discoveries are also discussed, including development of the voltaic pile, the use of chlorine to purify water, and the discovery of element 97, berkelium. This is the fourth consecutive year that Schatz has written an anniversaries article (1-3). Although most readers probably do not plan to be teaching in the years 2097-3000, these articles can make a nice addition to your file of readily available historical information for use now in meeting NSES Content Standard G (4). In contrast to the short historical summaries, an in-depth account of the work of Herman Boerhaave is provided by Trinity School (NY) teacher Damon Diemente. You cannot recall having heard of Boerhaave? Diemente explains in detail how Boerhaave's scientific observations, imperfect though they were, contributed significantly to the understanding of temperature and heat by scientists who followed him. Chemical demonstrations attract the interest of most of us, and Kathy Thorsen discusses several that appeared in Chem 13 News during the past year (pp 18-20). Included are demonstrations relating to LeCh鈚elier's principle, electronegativity, and the synthesis and reactions of carbon monoxide. Ideas for investigating the hydrophobic nature of Magic Sand are given in JCE Classroom Activity #23 (pp 40A-40B) and in an article by Robert Goldsmith (p 41). The 1999 Nobel Prize in chemistry and the research that led to the awards are discussed in an article beginning on p 14. An account of the 1998 winners appeared in last January's issue (5), providing the basis for another convenient resource file. Water droplets on a surface of Magic Sand. For many students electrochemistry is among the least favorite of the topics included in first- or second-year high school chemistry - despite the many interesting applications that students encounter every day. There are many reasons why students find the topic difficult, but misconceptions about current flow seem to present the largest obstacle to developing a conceptual understanding of electrochemical processes. Two university faculty members and a high school teacher, Huddle, White, and Rogers, have developed a teaching model to help students confront and overcome their misconceptions (pp 104-110). They have conducted studies of the impact of the model's use on student learning in both high school and introductory college chemistry courses. Particularly encouraging were the learning gains made by students with weak academic backgrounds. An action research project focused on student perspectives of small-group learning is described by Towns, Kreke, and Fields (pp 111-119). Although the project involved upper-division undergraduate university students, action research can be useful to any chemistry teacher who wishes to systematically examine and improve instructional methods and strategies. This article may be especially interesting to readers who frequently employ small-group learning techniques in their classroom. Advances in the technology of multimedia delivery are having an impact on the format in which new JCE Software releases are available. In particular, CD-ROM and Internet browsers are becoming increasingly important as the medium and method of access respectively. To better understand what is available for use in your classroom, read the article by Jon Holmes and Nancy Gettys (pp

  10. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-07-01

    Secondary School Feature Articles * Super Science Connections, by Patricia B. McKean, p 916 * A pHorseshoe, by Roger Plumsky, p 935 National Conferences in Your Part of the Country For the past several months, considerable space in this column has been devoted to forthcoming national conferences and conventions and to highlights of conferences past. For some of us, location is fairly unimportant; but for most of us travel costs and time are both factors to consider when choosing a conference. The community of high school chemistry teachers is favored by the number of national conventions and conferences that are held each year in different locations. In 1999, for example, the spring National Meeting of the American Chemical Society was in Anaheim and the National Science Teachers Association National Convention was in Boston. This summer CHEMED '99 will be held in Fairfield, CT, August 1-5, and the fall National ACS Meeting will be in New Orleans. Teachers from the mid-South especially should consider attending the High School Program at New Orleans, described below by Lillie Tucker Akin, Chairperson of the Division's High School Program Committee. The event will be held on Sunday to minimize conflicts with the beginning of the school year. JCE at CHEMED '99 Stop by the JCE booth at CHEMED '99 in the exhibits area to learn more about the wide array of print and nonprint resources you can use in your classroom and laboratory. Members of the editorial staff will be on hand to talk with you. You are invited to participate in a workshop, "Promoting Active Learning through JCE Activity Sheets and Software", on Monday, August 1, 8:30-10:30. The free hands-on workshop is number WT11 and we encourage you to include it among your choices in the blanks provided on the third page of the registration form. We will also conduct an interactive session to listen to ideas for making the Journal more useful to you. Check the final program for location and time or inquire at the JCE exhibit booth. NSTA in Boston For the representatives of the Journal, the highlight of the National Science Teachers Association Convention was visiting with the many readers who stopped by the JCE booth. Among them were several who have authored an article or reviewed manuscripts. We hope that number increases from year to year. JCE exists for its readers and because many readers are willing to devote the time and effort necessary to write a manuscript and revise it based on peer review. The convention offered such a variety of opportunities to acquire useful information that it is impossible to name a single highlight, or even to list the top ten. Representative of the many outstanding chemistry-oriented sessions presented by high school teachers were "Ultraviolet, Visible and Infrared Spectroscopy in the Chemistry and Physics Laboratory", "Kool Conversions in a Block Schedule", and "Hot Packs, Cold Packs, and a Six-Pack of Chemistry Projects". Reports from Other Journals On pages 882-885, Steve Long and Kathy Thorsen have summarized interesting articles that have appeared recently in The Science Teacher and Chem 13 News, respectively. Even if you are a regular reader of one or both of these journals, you will enjoy reading these summaries. Steve and Kathy have done a great job of highlighting interesting and useful information. I thank both of them for these fine contributions to the Journal. High School Day in New Orleans Mark August 22, 1999, on your calendar now and plan to attend High School Chemistry Day at the National ACS Meeting in New Orleans. The High School Program Committee, with support from local ACS sections, has planned an extravaganza of workshops and presentations, including environmental programs and workshops conducted by Sargent-Welch; an afternoon of instrumentation by Buck Laboratories with the Alabama Science in Motion vans and drivers to show how to transport chemistry on wheels; 12 demonstrations by nationally recognized chemical demonstration experts; a series of nine oral presentations on &

  11. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-09-01

    Secondary School Feature Articles * Authentic Research within the Grasp of High School Students, by Annis Hapkiewicz, p 1212 * JCE Classroom Activity #19: Blueprint Photography by the Cyanotype Process, by Glen D. Lawrence and Stuart Fishelson, p 1216A Author Recognition A new program has been instituted to recognize high school teachers who are authors or coauthors of manuscripts published in the Journal. In May, letters were sent to teachers who wrote articles published in JCE beginning with Volume 74 (1997). If you were an author, you should have received a letter from us in late May or early June stating that your high school principal has been sent a Certificate of High School Author Recognition to be presented to you at a suitable occasion. Because the letters were sent late in the school year, you may not see the certificate until fall, or you may not receive your letter until then if we had only your school address. If you have authored or coauthored an article published in JCE and did not receive a letter, please contact me using the information about the Secondary School Chemistry Editor appearing on the Information Page in this issue. Syllabus Swap In the August issue, this column contained an invitation to exchange high school syllabi. The day after my copy of the August issue arrived, I received an email from a teacher indicating an interest in participating in an exchange. If you are interested, check the August "Especially for High School Chemistry Teachers" column for a brief discussion of the informal exchange program, or contact me. Research Conducted by High School Students In his June 1999 editorial "Learning Is a Do-It-Yourself Activity", p 725, John Moore wrote about the need to engage students actively in the learning process. As I have mentioned in this column previously, research conducted by students is one means of accomplishing this goal. In this issue, p 1212, Annis Hapkiewicz explains how she has drawn her Okemos [Michigan] High School students into a class research project that employs simple materials but leads to an elegant solution. It is highly likely that her students' conceptual understanding of solution properties, density, heat capacity, phase change, diffusion, and scientific inquiry was greatly enhanced by the experience. Other accounts of research by high school students in class, small-group, and individual settings will be published in future issues. I hope that the various approaches described will stimulate new ideas for student-conducted research to facilitate learning. One frustration that high school teachers and students may experience is difficult access to instrumentation needed to carry out investigations. Calculator Based Laboratory (CBL) and other new technologies provide some relatively low-cost solutions to the problem, but the cost of specialized sensors can still be a barrier. In this issue a method for constructing an electrode for determining carbon dioxide concentration is described (p 1253). The article is not identified with Secondary School Chemistry mark (t) because it might not be of interest to a large number of high school teachers, but if the idea is appealing I encourage you to read the article. JCE has received several submissions from high school teachers describing devices constructed by their students, so I know there is some interest in low-cost build-it-yourself instrumentation. If you are among those who find this type of article interesting, please let me know. It will guide me in assigning the SSC icon to articles. Beginning Anew, Again For many readers, this issue will arrive only a few weeks or days before the beginning of the new school year. Others will already have begun the new school year. One of the joys of teaching lies in the cyclic nature of the school year. Ideas from summer workshops and conferences can be developed and implemented. Fresh faces in our classrooms provide another opportunit

  12. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-06-01

    Secondary School Feature Article * JCE Classroom Activity #18: Photochemistry and Pinhole Photography: An Interdisciplinary Experiment, by Angeliki A. Rigos and Kevin Salemme, p 736A High School Program at Anaheim ACS Meeting Congratulations to Barbara Sitzman of Chatsworth High School (Los Angeles) and her committee for organizing an outstanding day of activities! With support from the Southern California Section of the American Chemical Society and the encouragement of Tom Wildeman, CHED Program Committee Chair, the program attracted a large number of Southern California teachers and some from much greater distances. A synopsis of some of the day's activities is included in the Chemical Education Program Meeting Report, p 747. Other workshop topics included gel chromatography, forensic chemistry, art preservation and authentication, well water purification, and toxins in waste water. Also, a workshop on fitting polymers into the chemistry course was conducted by the Polymer Ambassadors. I thank Mickey Sarquis, founding editor of the JCE Secondary School Chemistry Section, for joining me in conducting an information workshop. The pictures appearing on this page were taken at the High School/College Interface Luncheon, which featured an address by Paul Boyer. In addition to the opportunity to visit with colleagues, enjoy a meal together, and win door prizes, those in attendance enjoyed a lively hands-on workshop led by Michael Tinnesand, Department Head of K-12 Science, ACS Education Division. Don't you wish you could have attended the High School Program? Plan Now: High School Program in New Orleans Mark your calendar for Sunday, August 22, 1999. The Fall ACS National Meeting will be held in New Orleans and the High School Program is scheduled on Sunday so that teachers will be able to avoid conflicts with the opening of the school year. Teachers in the Mid-South region are especially encouraged to plan on attending an outstanding program put together by Lillie Tucker Akin and her committee. Watch the Journal for program and registration information. Glenn Seaborg Memorial Periodic Table Quilt Raffle Harvey Gendreau of Framingham High School, MA, reports that Barbara McCarty, award-winning quilter and president of the Wayside Quilters Guild, has made a wall-sized periodic table quilt to honor the memory of Glenn Seaborg. The quilt will be raffled at ChemEd99 and funds from the raffle will be used to defray conference costs. The quilt is 2.5 meters wide by 1.5 meters high and the element squares are 13 cm on each side. Each of the 109 element squares contains the appliqu of the symbol and has stenciling for its atomic number and mass. The major periodic families are color coded and the border fabric has an eye-catching symbolic atom design. Nine colors for the elements include royal blue, deep purple, lilac, pink, burgundy and gold. The element square for seaborgium, atomic number 106, has been autographed by Glenn T. Seaborg. A certificate of authenticity will accompany the quilt. This is a unique opportunity to win a classroom (or home) art treasure. Each ticket is 2 or a book of 3 is 5. Tickets may be purchased on the ChemEd99 registration form and will be included in your conference packet. The quilt will be on display at the exposition hall and additional tickets can be purchased at the Unlimited Potential booth. Drawing will be on Wednesday, August 4th, in the expo area when door prizes are announced. You need not be present to win. Information about ChemEd99 may be obtained online at http://www.sacredheart.edu/chemed/. 1999 CMA Catalyst Awards Special congratulations to the High School and Pre-High School award recipients. National Winners are George R. Hague, Dallas, TX, and Wayne Goates, Goddard, KS. Regional winners are Rhonda Lynn Reist, Olathe, KS, and Anne Marie Holbrook, Cincinnati, OH. A complete list of the awardees, including the post-high-school recipients, is in the News & Announcements section of this issue,

  13. [Diversity and microstructure of quitons (Mollusca: Polyplacophora) from the Caribbean of Costa Rica].

    PubMed

    Garc韆-R韔s, Cedar I; Alvarez-Ruiz, Migdalia

    2011-03-01

    Diversity and microstructure of quitons (Mollusca: Polyplacophora) from the Caribbean of Costa Rica. The polyplacophorans of the coral reef on the Caribbean coast of Costa Rica have been insufficiently studied. The examination of coral rubble accumulated in the shallow sublitoral waters on four collection stations in Provincia Lim髇 revealed a higher diversity of chitons than was documented. From the country eight species were previously known: Ischnochiton erythronotus (C.B. Adams 1845); Ischnoplax pectinata (Sowerby 1840); Stenoplax boogii (Haddon 1886); S. purpurascens (C.B. Adams 1845); Acanthopleura granulata (Gmelin 1791); Chiton marmoratus Gmelin 1791; C. tuberculatus Linnaeus 1758 and Acanthochitona rhodea (Pilsbry 1893). This study added five more species that are reported here for the first time: Callistochiton portobelensis Ferreira 1976; Ischnochiton kaasi Ferreira 1987; I. pseudovirgatus Kaas 1972; Acanthochitona balesae Abbott 1954 and Cryptoconchus floridanus (Dall 1889). PMID:21516641

  14. Studies in rotational flows especially hydromagnetic

    Microsoft Academic Search

    G. S. S. Ludford

    1974-01-01

    Modern asymptotic methods have been used to investigate (1) magnetohydrodynamic duct flow in strong transverse magnetic fields, especially the occurrence of fully developed conditions and inertial effects; (2) the ion probe; (3) hydrodynamic stability, especially magnetohydrodynamic and using a new approach; (4) rotating flows, including stagnation points, almost rigid rotation, and vortex breakdown; (5) viscous boundary layers in shear flow,

  15. Algunas falacias sobre la 'nueva economa' GUILLERMO DE LA DEHESA

    E-print Network

    Bilbao Arrese, Jes鷖 Mario

    crean redes, pero esas redes necesitan vender algo, transportarlo y entregarlo al cliente o al coste, de mayor productividad y de mayor rentabilidad) la creaci髇 de las nuevas redes de informaci髇, al final, a colonizar dichas redes y afianzarse a鷑 m醩 en sus sectores productivos generando menores

  16. LAS NUEVAS TECNOLOG虯S PARA EL APOYO DE LOS PROCESOS EDUCATIVOS

    Microsoft Academic Search

    Francisco Morf韓

    Con 醤imo y necesidad crecientes, un mayor n鷐ero de instituciones educativas est醤 destinando recursos a la creaci髇 de instancias que estudien las formas en que las nuevas tecnolog韆s de informaci髇 y comunicaci髇 podr醤 emplearse como veh韈ulo de mediaciones educativas. Estos estudios cuentan ya con una historia de poco m醩 de 40 a駉s y los usos y aplicaciones de estas herramientas

  17. Veinte a駉s de ciudades globales: ideas, mitos y nuevas evidencias

    Microsoft Academic Search

    Jos A. Gavinha

    2008-01-01

    El an醠isis de datos sobre el volumen de ventas de empresas globales pone de manifiesto que la globalizaci髇 de la econom韆 no ha sido ni un conjunto de procesos regular, ni est dominada por un reducido n鷐ero de sectores vinculados a las nuevas tecnolog韆s. En realidad, ha seguido fases, cada una caracterizada por cambios en los papeles de varios sectores.

  18. JOS ROSAS VERA La Ilusin de una Nueva Arquitectura en

    E-print Network

    Entekhabi, Dara

    Venezuela JOS ROSAS VERA La Ilusi髇 de una Nueva Arquitectura en Venezuela 15 los noventas. mismo arquitectura internacional del en el Concierto Internacional de valorizaci髇 global. Azier Calvo, in his arquitectura o materiales, sino que en relaci髇 al encargo audience is greater. Juan Manuel Pelaez

  19. JOS ROSAS VERA La Ilusin de una Nueva Arquitectura en

    E-print Network

    Entekhabi, Dara

    Venezuela JOS茅 ROSAS VERA La Ilusi贸n de una Nueva Arquitectura en Venezuela 15 los noventas. mismo arquitectura internacional del en el Concierto Internacional de valorizaci贸n global. Azier Calvo, in his arquitectura o materiales, sino que en relaci贸n al encargo audience is greater. Juan Manuel Pelaez

  20. Development of a Monoclonal Antibody for the Detection and Quantification of Predation on Slugs within the Arion hortensis agg. (Mollusca: Pulmonata)

    Microsoft Academic Search

    W. O. C. Symondson; M. L. Erickson; J. E. Liddell

    1999-01-01

    The Arion hortensis agg. (Mollusca: Pulmonata) are major slug pests of agriculture and horticulture throughout much of the temperate World. A monoclonal antibody was created that could specifically identify and quantify the remains of these slugs within the carabid predator Pterostichus melanarius Illiger, a polyphagous species found in arable crops in Europe and North America. The antibody was shown to

  1. Catalogue of the type specimens deposited in the Mollusca Collection of the Museu Nacional / UFRJ, Rio de Janeiro, Brazil.

    PubMed

    Pimenta, Alexandre Dias; Monteiro, J鷏io C閟ar; Barbosa, Andr Favaretto; Salgado, Norma Campos; Coelho, Arnaldo Campos Dos Santos

    2014-01-01

    A curatorial revision of the type specimens deposited in the Mollusca Collection of the Museu Nacional / UFRJ, Rio de Janeiro, Brazil (MNRJ) revealed the existence of 518 lots of type specimens (holotypes, neotypes, syntypes and paratypes) for 285 names of molluscan taxa from 88 families, including 247 gastropods, 30 bivalves, three cephalopods and five scaphopods. A total of 106 holotypes and one neotype are deposited in the MNRJ. Type material for ten nominal taxa described as being deposited in the MNRJ was not located; the probable reasons are discussed. Some previously published erroneous information about types in the MNRJ is rectified. A total of 37 type specimens are illustrated. PMID:24871828

  2. Annotated type catalogue of the Orthalicoidea (Mollusca, Gastropoda) in the Museum f黵 Naturkunde, Berlin

    PubMed Central

    Breure, Abraham S.H.

    2013-01-01

    Abstract The type status is described of 96 taxa classified within the superfamily Orthalicoidea and present in the Mollusca collection of the Museum f黵 Naturkunde der Humboldt-Universit鋞 zu Berlin. Lectotypes are designated for the following taxa: Orthalicus elegans Rolle, 1895; Bulimus maranhonensis Albers, 1854; Orthalicus nobilis Rolle, 1895; Orthalichus tricinctus Martens, 1893. Orthalicus sphinx tresmariae is introduced as new name for Zebra sphinx turrita Strebel, 1909, not Zebra quagga turrita Strebel, 1909. The following synonyms are established: Zebra crosseifischeri Strebel, 1909 = Orthalicus princeps fischeri Martens, 1893; Orthalicus isabellinus Martens, 1873 = Orthalicus bensoni (Reeve, 1849); Zebra zoniferus naesiotes Strebel, 1909 = Orthalicus undatus (Brugui鑢e, 1789); Porphyrobaphe (Myiorthalicus) dennisoni pallida Strebel, 1909 = Hemibulimus dennisoni (Reeve, 1848); Zebra delphinus pumilio Strebel, 1909 = Orthalicus delphinus (Strebel, 1909); Orthalicus (Laeorthalicus) reginaeformis Strebel, 1909 = Corona perversa (Swainson, 1821); Bulimus (Eurytus) corticosus Sowerby III, 1895 = Plekocheilus (Eurytus) stuebeli Martens, 1885. The taxon Bulimus (Eudioptus) psidii Martens, 1877 is now placed within the family Sagdidae, tentatively in the genus Platysuccinea. Appendices are included with an index to all the types of Orthalicoidea extant (including those listed by K鰄ler 2007) and a partial list of letters present in the correspondence archives. PMID:23794831

  3. Genetic divergence and geographic variation in the deep-water Conus orbignyi complex (Mollusca: Conoidea)

    PubMed Central

    Puillandre, Nicolas; Meyer, Christopher P.; Bouchet, Philippe; Olivera, Baldomero M.

    2011-01-01

    Puillandre, N. et al. (2010) Genetic divergence and geographic variation in a deep-water cone lineage: molecular and morphological analyses of the Conus orbignyi complex (Mollusca: Conoidea). The cone snails (family Conidae) are a hyperdiverse lineage of venomous gastropods. Two standard markers, COI and ITS2, were used to define six genetically-divergent groups within a subclade of Conidae that includes Conus orbignyi; each of these was then evaluated based on their shell morphology. We conclude that three forms, previously regarded as subspecies of Conus orbignyi are distinct species, now recognized as Conus orbignyi, Conus elokismenos and Conus coriolisi. In addition, three additional species (Conus pseudorbignyi, Conus joliveti and Conus comatosa) belong to this clade. Some of the proposed species (e.g., Conus elokismenos) are possibly in turn complexes comprising multiple species. Groups such as Conidae illustrate the challenges generally faced in species delimitation in biodiverse lineages. In the case of the Conus orbignyi complex, not only are there definable, genetically divergent lineages, but also considerable geographic variation within each group. Our study suggests that an intensive analysis of multiple specimens within a single locality helps to minimize the confounding effects of geographic variation and can be a useful starting point for circumscribing different species within such a confusing complex. PMID:21712968

  4. Comparative mitogenomic analysis reveals cryptic species: A case study in Mactridae (Mollusca: Bivalvia).

    PubMed

    Shen, Xin; Meng, Xue Ping; Chu, Ka Hou; Zhao, Na Na; Tian, Mei; Liang, Meng; Hao, Jue

    2014-12-01

    The Chinese surf clam Mactra chinensis Philippi, 1846 is a commercially important marine bivalve belonging to the family Mactridae (Mollusca: Bivalvia). In this study, the M. chinensis mitochondrial genomic features are analyzed. The genome has 34 genes on the same strand, lacking atp8 and both trnS (trnS1 and trnS2) as compared with the typical gene content of metazoan mitochondrial genomes. The A+T content of M. chinensis mitochondrial genome is 63.72%, which is slightly lower than that of M. veneriformis (67.59%) and Coelomactra antiquata (64.33% and 64.14% for the samples from Ri Zhao, Shandong Province, and Zhang Zhou, Fujian Province, China, respectively) in the same family. There are 22 NCRs in the M. chinensis mitochondrial genome, accounting for 12.91% of the genome length. The longest NCR (1,075bp in length) is located between trnT and trnQ. A TRS (127bp8.15) accounts for 96.3% (1,035/1,075) of this NCR. The occurrence of TRS in NCR is shared by the two Mactra mitochondrial genomes, but is not found in the two Coelomactra mitochondrial genomes. A phylogenetic tree constructed based on 12 PCGs of 25 bivalve mitochondrial genomes shows that all seven genera (Mactra, Coelomactra, Paphia, Meretrix, Solen, Mytilus, and Crassostrea) constitute monophyletic groups with very high support values. Pairwise genetic distance analyses indicate that the genetic distance of C. antiquata from the two localities is 0.084, which is greater than values between congeneric species, such as those in Mactra, Mytilus, Meretrix, and Crassostrea. The results show that the C. antiquata from the two localities represent cryptic species. PMID:25247670

  5. An SCD gene from the Mollusca and its upregulation in carotenoid-enriched scallops.

    PubMed

    Li, Xue; Ning, Xianhui; Dou, Jinzhuang; Yu, Qian; Wang, Shuyue; Zhang, Lingling; Wang, Shi; Hu, Xiaoli; Bao, Zhenmin

    2015-06-10

    Carotenoids are a diverse group of red, orange, and yellow pigments that act as vitamin A precursors and antioxidants. Animals can only obtain carotenoids through their diets. Amongst the carotenoids identified in nature, over one third are of marine origin, but current research on carotenoid absorption in marine species is limited. Bivalves possess an adductor muscle, which is normally white in scallops. However, a new variety of Yesso scallop (Patinopecten yessoensis), the 'Haida golden scallop', can be distinguished by its adductor muscle's orange colour, which is caused by carotenoid accumulation. Studying the genes related to carotenoid accumulation in this scallop could benefit our understanding of the mechanisms underlying carotenoid absorption in marine organisms, and it could further improve scallop breeding for carotenoid content. Stearoyl-CoA desaturase (SCD) is the rate-limiting enzyme in the production of monounsaturated fatty acids, which enhance carotenoid absorption. Here, the full-length cDNA and genomic DNA sequences of the SCD gene from the Yesso scallop (PySCD) were obtained. The PySCD gene consisted of four exons and three introns, and it contained a 990-bp open reading frame encoding 329 amino acids. It was ubiquitously expressed in adult tissues, embryos and larvae of both white Yesso scallops and 'Haida golden' scallops. Although the expression pattern of PySCD in both types of scallops was similar, significantly more PySCD transcripts were detected in the 'Haida golden' scallops than in the white scallops. Elevated PySCD expression was found in tissues including the adductor muscle, digestive gland, and gonad, as well as in veliger larvae. This study represents the first characterisation of an SCD gene from the Mollusca. Our data imply that PySCD functions in multiple biological processes, and it might be involved in carotenoid accumulation. PMID:25816753

  6. Nacre and false nacre (foliated aragonite) in extant monoplacophorans (=Tryblidiida: Mollusca)

    NASA Astrophysics Data System (ADS)

    Checa, Antonio G.; Ram韗ez-Rico, Joaqu韓; Gonz醠ez-Segura, Alicia; S醤chez-Navas, Antonio

    2009-01-01

    Extant monoplacophorans (Tryblidiida, Mollusca) have traditionally been reported as having an internal nacreous layer, thus representing the ancestral molluscan condition. The examination of this layer in three species of Neopilinidae ( Rokopella euglypta, Veleropilina zografi, and Micropilina arntzi) reveals that only V. zografi secretes an internal layer of true nacre, which occupies only part of the internal shell surface. The rest of the internal surface of V. zografi and the whole internal surfaces of the other two species examined are covered by a material consisting of lath-like, instead of brick-like, crystals, which are arranged into lamellae. In all cases examined, the crystallographic c-axis in this lamellar material is perpendicular to the surface of laths and the a-axis is parallel to their long dimension. The differences between taxa relate to the frequency of twins, which is much higher in Micropilina. In general, the material is well ordered, particularly towards the margin, where lamellae pile up at a small step size, which is most likely due to processes of crystal competition. Given its morphological resemblance to the foliated calcite of bivalves, we propose the name foliated aragonite for this previously undescribed biomaterial secreted by monoplacophorans. We conclude that the foliated aragonite probably lacks preformed interlamellar membranes and is therefore not a variant of nacre. A review of the existing literature reveals that previous reports of nacre in the group were instead of the aragonitic foliated layer and that our report of nacre in V. zografi is the first undisputed evidence of nacre in monoplacophorans. From the evolutionary viewpoint, the foliated aragonite could easily have been derived from nacre. Assuming that nacre represents the ancestral condition, as in other molluscan classes, it has been replaced by foliated aragonite along the tryblidiidan lineage, although the fossil record does not presently provide evidence as to when this replacement took place.

  7. Unionid bivalves (Mollusca: Bivalvia: Unionidae) of Presque Isle Bay, Erie, Pennsylvania

    USGS Publications Warehouse

    Masteller, E.C.; Maleski, K.R.; Schloesser, D.W.

    1993-01-01

    The purpose of this study was to determine species composition and relative abundance of unionid bivalves (Mollusca: Bivalvia: Unionidae) in Presque Isle Bay, Erie, Pennsylvania 1990-1992. This information was compared with data from the only other extensive survey of unionids in the bay conducted in 1909-1911 (Ortmann 1919) to assess changes over the 80 years preceding the present study. A total of 1,540 individuals representing 18 species were collected in 1990-1992. Five relatively common species (between 7 and 42% of total individuals), six uncommon species (2 and 6%), and seven rare species (<1%) were found. The rare species were Anodontoides ferussacianus, Lasmigona costata, Ligumia recta, Ptychobranchus fasciolaris, Quadrula pustulosa pustulosa, Strophitus undaulatus, and Truncilla donaciformis. Five of the species found in Presque Isle Bay (Leptodea fragilis, Ligumia nasuta, Potamilus alatus, Quadrula quadrula, and Truncilla donaciformis) are listed as critically imperiled and one species (Truncilla truncata) as extirpated in the State of Pennsylvania by the Western Pennsylvania Conservancy. Comparisons between unionid populations in 1909-1911 and 1990-1992 indicate few substantial changes occurred during the past 80 years. A total of 22 species were found; 21 in 1909-1911 and 18 in 1990-1992. Seventeen species were found in both studies, an additional four in 1909-1911 and one in 1990-1992. The relative abundance of 11 of the 17 species found in both studies remained stable (i.e., common or uncommon) over the past 80 years. Only four species listed as uncommon in 1909-1911 were listed as rare in 1990-1992. However, the invasion of the zebra mussel (Dreissena polymorpha) is considered a threat to the continued existence of the entire Unionidae fauna in Presque Isle Bay, a unique habitat of the Great Lakes.

  8. Homology and homoplasy of swimming behaviors and neural circuits in the Nudipleura (Mollusca, Gastropoda, Opisthobranchia).

    PubMed

    Newcomb, James M; Sakurai, Akira; Lillvis, Joshua L; Gunaratne, Charuni A; Katz, Paul S

    2012-06-26

    How neural circuit evolution relates to behavioral evolution is not well understood. Here the relationship between neural circuits and behavior is explored with respect to the swimming behaviors of the Nudipleura (Mollusca, Gastropoda, Opithobranchia). Nudipleura is a diverse monophyletic clade of sea slugs among which only a small percentage of species can swim. Swimming falls into a limited number of categories, the most prevalent of which are rhythmic left-right body flexions (LR) and rhythmic dorsal-ventral body flexions (DV). The phylogenetic distribution of these behaviors suggests a high degree of homoplasy. The central pattern generator (CPG) underlying DV swimming has been well characterized in Tritonia diomedea and in Pleurobranchaea californica. The CPG for LR swimming has been elucidated in Melibe leonina and Dendronotus iris, which are more closely related. The CPGs for the categorically distinct DV and LR swimming behaviors consist of nonoverlapping sets of homologous identified neurons, whereas the categorically similar behaviors share some homologous identified neurons, although the exact composition of neurons and synapses in the neural circuits differ. The roles played by homologous identified neurons in categorically distinct behaviors differ. However, homologous identified neurons also play different roles even in the swim CPGs of the two LR swimming species. Individual neurons can be multifunctional within a species. Some of those functions are shared across species, whereas others are not. The pattern of use and reuse of homologous neurons in various forms of swimming and other behaviors further demonstrates that the composition of neural circuits influences the evolution of behaviors. PMID:22723353

  9. Drive assembly, especially for motor vehicles

    SciTech Connect

    Striebich, H.

    1981-10-13

    A drive assembly, especially for motor vehicles, of the type comprising an internal combustion engine and an exhaust gas turbine unit including an exhaust gas driven turbine is improved by virtue of structure for utilizing the heat energy of the exhaust gases of the internal combustion engine in addition to the kinetic energy. According to a preferred embodiment, the exhaust gas turbine unit comprises, in addition to the exhaust gas turbine, a compressor and a secondary turbine for deriving power from the heat energy of the exhaust gases. Still further, another feature includes the provision of a heat exchanger for transferring thermal energy from the exhaust gases to a working medium after the working medium has been compressed by the compressor, the heat exchanger being formed by hollow blades of the exhaust gas driven turbine.

  10. An unusual case of gender-associated mitochondrial DNA heteroplasmy: the mytilid Musculista senhousia (Mollusca Bivalvia)

    PubMed Central

    Passamonti, Marco

    2007-01-01

    Background Doubly Uniparental Inheritance (DUI) represents the most outstanding exception to matrilinear inheritance of mitochondrial DNA (mtDNA), typical of Metazoa. In a few bivalve mollusks, two sex-linked mtDNAs (the so-called M and F) are inherited in a peculiar way: both daughters and sons receive their F from the mother, whereas sons inherit M from the father (males do not transmit F to their progeny). This realizes a double mechanism of transmission, in which M and F mtDNAs are inherited uniparentally. DUI systems represent a unique experimental model for testing the evolutionary mechanisms that apply to mitochondrial genomes and their transmission patterns as well as to mtDNA recombination. Results A new case of DUI is described in Musculista senhousia (Mollusca: Bivalvia: Mytilidae). Its heteroplasmy pattern is in line with standard DUI. Sequence variability analysis evidenced two main results: F haplotypes sequence variability is higher than that of M haplotypes, and F mitochondrial haplotypes experience a higher mutation rate in males' somatic tissues than in females' ones. Phylogenetic analysis revealed also that M. senhousia M and F haplotypes cluster separately from that of the other mytilids. Conclusion Sequence variability analysis evidenced some unexpected traits. The inverted variability pattern (the F being more variable than M) was new and it challenges most of the rationales proposed to account for sex-linked mtDNA evolution. We tentatively related this to the history of the Northern Adriatic populations analyzed. Moreover, F sequences evidenced a higher mutation level in male's soma, this variability being produced de novo each generation. This suggests that mechanisms evolved to protect mtDNA in females (f.i. antioxidant gene complexes) might be under relaxed selection in males. Phylogenetic analysis of sex-linked haplotypes confirmed that they have switched their roles during the evolutionary history of mytilids, at variance to what has been observed in unionids. Consequently, reciprocal monophyly of M and F lineages got easily lost because of role-reversals and consequent losses of M lineages, as already observed in Mytilus. PMID:17767735

  11. La ciencia del lenguaje estudia el fenmeno de las TIC, redes sociales y nuevas formas de comunicacin en la UA

    E-print Network

    Escolano, Francisco

    La ciencia del lenguaje estudia el fen髆eno de las TIC, redes sociales y nuevas formas de comunicaci髇 en la UA Alicante, 8 de marzo de 2013 Las TIC, las redes sociales y las nuevas formas de.0: las TIC, redes sociales y nuevas formas de comunicaci髇" comienza el lunes 11 de marzo de 2013 y hasta

  12. A new leech species of Semiscolex (Arhynchobdellida: Semiscolecidae) from Lake Catemaco, Veracruz, Mexico Especie nueva de sanguijuela del g閚ero Semiscolex (Arhynchobdellida: Semiscolecidae) del lago de Catemaco, Veracruz, M閤ico

    Microsoft Academic Search

    Alejandro Oceguera-Figueroa

    2006-01-01

    Semiscolex lamothei sp. nov. from Catemaco lake, Veracruz, M閤ico, is described based on the examination of 18 specimens. The new species differs from other species of the genus by the presence of 1\\/2 + 5 + 1\\/2 annuli between gonopores. The new species has morphological features previously not described for any other member of the genus, such as well-developed ejaculatory

  13. Assessing metal contamination from construction and demolition (C&D) waste used to infill wetlands: using Deroceras reticulatum (Mollusca: Gastropoda).

    PubMed

    Staunton, John A; Mc Donnell, Rory J; Gormally, Michael J; Williams, Chris D; Henry, Tiernan; Morrison, Liam

    2014-11-01

    Large quantities of construction and demolition waste (C&D) are produced globally every year, with little known about potential environmental impacts. In the present study, the slug, Deroceras reticulatum (Mollusca: Gastropoda) was used as the first biomonitor of metals (Ag, As, Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Se, Ti, Tl, V and Zn) on wetlands post infilling with construction and demolition (C&D) waste. The bioaccumulation of As, Ba, Cd, Co, Sb, Se and Tl were found to be significantly elevated in slugs collected on C&D waste when compared to unimproved pastures (control sites), while Mo, Se and Sr had significantly higher concentrations in slugs collected on C&D waste when compared to known contaminated sites (mining locations), indicating the potential hazardous nature of C&D waste to biota. Identifying exact sources for these metals within the waste can be problematic, due to its heterogenic nature. Biomonitors are a useful tool for future monitoring and impact studies, facilitating policy makers and regulations in other countries regarding C&D waste infill. In addition, improving separation of C&D waste to allow increased reuse and recycling is likely to be effective in reducing the volume of waste being used as infill, subsequently decreasing potential metal contamination. PMID:25298023

  14. Molecular phylogenetic analysis supports a Gondwanan origin of the Hyriidae (Mollusca: Bivalvia: Unionida) and the paraphyly of Australasian taxa.

    PubMed

    Graf, Daniel L; Jones, Hugh; Geneva, Anthony J; Pfeiffer, John M; Klunzinger, Michael W

    2015-04-01

    The freshwater mussel family Hyriidae (Mollusca: Bivalvia: Unionida) has a disjunct trans-Pacific distribution in Australasia and South America. Previous phylogenetic analyses have estimated the evolutionary relationships of the family and the major infra-familial taxa (Velesunioninae and Hyriinae: Hyridellini in Australia; Hyriinae: Hyriini, Castaliini, and Rhipidodontini in South America), but taxon and character sampling have been too incomplete to support a predictive classification or allow testing of biogeographical hypotheses. We sampled 30 freshwater mussel individuals representing the aforementioned hyriid taxa, as well as outgroup species representing the five other freshwater mussel families and their marine sister group (order Trigoniida). Our ingroup included representatives of all Australian genera. Phylogenetic relationships were estimated from three gene fragments (nuclear 28S, COI and 16S mtDNA) using maximum parsimony, maximum likelihood, and Bayesian inference, and we applied a Bayesian relaxed clock model calibrated with fossil dates to estimate node ages. Our analyses found good support for monophyly of the Hyriidae and the subfamilies and tribes, as well as the paraphyly of the Australasian taxa (Velesunioninae, (Hyridellini, (Rhipidodontini, (Castaliini, Hyriini)))). The Hyriidae was recovered as sister to a clade comprised of all other Recent freshwater mussel families. Our molecular date estimation supported Cretaceous origins of the major hyriid clades, pre-dating the Tertiary isolation of South America from Antarctica/Australia. We hypothesize that early diversification of the Hyriidae was driven by terrestrial barriers on Gondwana rather than marine barriers following disintegration of the super-continent. PMID:25659337

  15. Biochemical profile of Achatina fulica (Mollusca: Gastropoda) after infection by different parasitic loads of Angiostrongylus cantonensis (Nematoda, Metastrongylidae).

    PubMed

    Tunholi-Alves, Vin韈ius Menezes; Tunholi, Victor Menezes; Amaral, Ludimila Santos; Mota, Esther Maria; Maldonado J鷑ior, Arnaldo; Pinheiro, Jairo; Garcia, Juberlan

    2015-01-01

    The effect of experimental infection by different parasitic loads of Angiostrongylus cantonensis (Nematode, Metastrongylidae) on the activities of the aminotransferases and concentration of total proteins, uric acid and urea in the hemolymph of Achatina fulica (Mollusca, Gastropoda) were investigated. There was a significant decrease in the concentration of total proteins in the exposed snails to 5000 or more larvae. This change was accompanied by an increase in the concentrations of urea and uric acid in the hemolymph, suggesting a higher rate of deamination of the amino acids. Besides this, variations in the activities of the aminotransferases were also observed, with the highest values recorded in the groups exposed to greater parasite load. These results suggest an increase in the use of total proteins, since there was increased formation of nitrogenous catabolites, in conformity with an increase in the aminotransferase activities. Infection was verified by the fact that L3 larvae recovered from the snails was proportion to the exposure dose of L1 larvae. Histopathological results also indicated presence of an inflammatory cell infiltrate, favoring an increase of both transaminases. PMID:25308279

  16. Screening of antiangiogenic potential of twenty two marine invertebrate extracts of phylum Mollusca from South East Coast of India

    PubMed Central

    Gupta, Pankaj; Arumugam, Muthuvel; Azad, Raj Vardhan; Saxena, Rohit; Ghose, Supriyo; Biswas, Nihar Ranjan; Velpandian, Thirumurthy

    2014-01-01

    Objective To evaluate the antiangiogenic potential of twenty two marine invertebrate species of Phylum Mollusca from south east coast of India. Methods Live specimens of molluscan species were collected and their methanolic extracts were evaluated for preliminary antiangiogenic activity using the in ovo chick chorio-allantoic membrane assay. The extracts were further evaluated for in vivo antiangiogenic activity using chemical cautery induced corneal neovascularization assay in rats and oxygen induced retinopathy assay in rat pups. Results In the chick chorio-allantoic membrane assay, four methanolic extracts of marine molluscan species viz. Meretrix meretrix, Meretrix casta, Telescopium telescopium and Bursa crumena methanolic extracts exhibited noticeable antiangiogenic activity at the tested concentration of 200 礸 whereby they significantly inhibited the VEGF induced proliferation of new blood vessels. Among these four extracts, the methanolic extract of Meretrix casta exhibited relatively higher degree of antiangiogenic activity with an inhibitiory percentage (64.63%) of the VEGF induced neovascularization followed by the methanolic extracts of Telescopium telescopium (62.02%), Bursa crumena (60.48%) and Meretrix meretrix (47.01%). These four methanolic extracts were further evaluated for in vivo antiangiogenic activity whereby the methanolic extract of Telescopium telescopium exhibited most noticeable inhibition (42.58%) of the corneal neovascularization in rats in comparison to the sham treated group, and also exhibited most noticeable inhibition (31.31%) of the oxygen induced retinal neovascularization in rat pups in comparison to the hyperoxia group that was observed for considerable retinal neovascularization. Conclusions The significant antiangiogenic activity evinced by the extract of Telescopium telescopium merits further investigation for ocular neovascular diseases. PMID:25183067

  17. Aulas Informticas de libre acceso (Informtica, nuevas tecnologas y redes sociales)

    E-print Network

    Escolano, Francisco

    aulas inform谩ticas de libre acceso CAMPUS VIRTUAL CORREO ELECTR?NICO RED INAL脕MBRICA WIRELESS (wifi) SERVICIO DE PR?STAMO DE ORDENADORES PORT脕TILES EN BIBLIOTECAS AULA VIRTUAL P脕GINAS WEB PERSONALES DELAulas Inform谩ticas de libre acceso (Inform谩tica, nuevas tecnolog铆as y redes sociales) INTRODUCCI?N

  18. La Drosophila de las alas manchadas Una nueva plaga invasora en los frutales de Michigan

    E-print Network

    La Drosophila de las alas manchadas Una nueva plaga invasora en los frutales de Michigan Rufus Bulletin E-3140SP New November 2010 Introducci髇 La mosca Drosophila de alas manchadas (Drosophila mayor韆 de las moscas del vinagre atacan cuando la fruta esta da馻da. A diferencia de estas, la Drosophila

  19. INTERNET 2 : Las nuevas redes del futuro Juan Manuel Torres Moreno

    E-print Network

    Avignon et des Pays de Vaucluse, Universit de

    INTERNET 2 : Las nuevas redes del futuro Juan Manuel Torres Moreno Laboratorio Nacional de m醩 virtual) pero a鷑 mas impactante: la revoluci髇 de las redes de computadoras. Internet ha supuesto vistas. Internet constituye al mismo tiempo un mecanismo de difusi髇 mundial, de propagaci髇, interacci髇

  20. EL JARDN BOTNICO DE NUEVA YORK POLTICA DE ADQUISICIONES DEL DEPSITO DE ADN

    E-print Network

    Law, Wayne

    del Jard韓 Bot醤ico de Nueva York (NYBG) sirve como repositorio para las muestras de tejido congelado existentes de otras instituciones e individuos con la condici髇 de que sean relevantes y constantes con instituciones que se han registrado con CITES y que han recibido un n鷐ero cient韋ico de la instituci髇 y que

  1. A preliminary study of iron isotope fractionation in marine invertebrates (chitons, Mollusca) in near-shore environments

    NASA Astrophysics Data System (ADS)

    Emmanuel, S.; Schuessler, J. A.; Vinther, J.; Matthews, A.; von Blanckenburg, F.

    2014-10-01

    Chitons (Mollusca) are marine invertebrates that produce radulae (teeth or rasping tongues) containing high concentrations of biomineralized magnetite and other iron-bearing minerals. As Fe isotope signatures are influenced by redox processes and biological fractionation, Fe isotopes in chiton radulae might be expected to provide an effective tracer of ambient oceanic conditions and biogeochemical cycling. Here, in a pilot study to measure Fe isotopes in marine invertebrates, we examine Fe isotopes in modern marine chiton radulae collected from different locations in the Atlantic and Pacific oceans to assess the range of isotopic values, and to test whether or not the isotopic signatures reflect seawater values. Values of ?56Fe (relative to IRMM-014) in chiton teeth range from -1.90 to 0.00 (0.05 (2?) uncertainty in ?56Fe), probably reflecting a combination of geographical control and biological fractionation processes. Comparison with published local surface seawater Fe isotope data shows a consistent negative offset of chiton teeth Fe isotope compositions relative to seawater. Strikingly, two different species from the same locality in the North Pacific (Puget Sound, Washington, USA) have distinct isotopic signatures. Tonicella lineata, which feeds on red algae in the sublittoral zone, has a mean ?56Fe of -0.65 0.26 (2?, 3 specimens), while Mopalia muscosa, which feeds on both green and red algae in the eulittoral zone, shows lighter isotopic values with a mean ?56Fe of -1.47 0.98 (2?, 5 specimens). Three possible pathways are proposed to account for the different isotopic signatures: (i) physiologically controlled processes within the chitons that lead to species-dependent fractionation; (ii) diet-controlled variability due to different Fe isotope fractionation in the red and green algal food sources; and (iii) environmentally controlled fractionation that causes variation in the isotopic signatures of bioavailable Fe in the different tidal regions. Our preliminary results suggest that while chitons are not simple recorders of the ambient seawater Fe isotopic signature, Fe isotopes provide valuable information concerning Fe biogeochemical cycling in near-shore environments, and may potentially be used to probe sources of Fe recorded in different organisms.

  2. ESTs library from embryonic stages reveals tubulin and reflectin diversity in Sepia officinalis (Mollusca Cephalopoda).

    PubMed

    Bassaglia, Yann; Bekel, Thomas; Da Silva, Corinne; Poulain, Julie; Andouche, Aude; Navet, Sandra; Bonnaud, Laure

    2012-05-01

    New molecular resources regarding the so-called 搉on-standard models in biology extend the present knowledge and are essential for molecular evolution and diversity studies (especially during the development) and evolutionary inferences about these zoological groups, or more practically for their fruitful management. Sepia officinalis, an economically important cephalopod species, is emerging as a new lophotrochozoan developmental model. We developed a large set of expressed sequence tags (ESTs) from embryonic stages of S. officinalis, yielding 19,780 non-redundant sequences (NRS). Around 75% of these sequences have no homologs in existing available databases. This set is the first developmental ESTs library in cephalopods. By exploring these NRS for tubulin, a generic protein family, and reflectin, a cephalopod specific protein family,we point out for both families a striking molecular diversity in S. officinalis. PMID:22548232

  3. SURVIVAL AND MOVEMENTS OF AFRICAN PENGUINS, ESPECIALLY AFTER OILING.

    E-print Network

    de Villiers, Marienne

    SURVIVAL AND MOVEMENTS OF AFRICAN PENGUINS, ESPECIALLY AFTER OILING. by Philip Anthony Whittington of first recorded breeding and the success of rehabilitating oiled African Penguins were investigated using re-sightings of flipper-banded birds. Seventeen penguin colonies between Algoa Bay and Lambert's Bay

  4. different Drosophila species, especially those that are specialized for specific

    E-print Network

    VanRullen, Rufin

    different Drosophila species, especially those that are specialized for specific hosts (e.g., D.F. (1920). Egg-laying reactions in the pomace fly, Drosophila. J. Exp. Zool. 31, 326341. 2. Dethier, V of Drosophila sechellia specialization: Oviposition behavior toward the major aliphatic acids of its host plant

  5. An especial skill in elite wheelchair basketball players.

    PubMed

    Fay, K; Breslin, G; Czy?, S H; Pizlo, Z

    2013-08-01

    We aimed to investigate whether an especial skill is present in elite wheelchair basketball players when taking twenty shots with a regular basketball from five different distances (11 ft, 13 ft, 17 ft, & 19 ft) from the basket including the free throw line (15 ft). Twelve elite male basketball players participated. The results showed that as distance increased shot accuracy decreased in line with force by variability predictions for the 11 ft, 13 ft, 17 ft, & 19 ft distances. However, shot performance at the free throw line where players are more familiar with practicing free throw shots did not follow this trend. A linear regression line was drawn to predict performance at the free throw line based on nearer (11 ft & 13 ft) and farer (17 ft & 19 ft) distances to the basket, this was then compared to actual performance. A significant difference between actual and predicted scores was found (p<.05) supporting the presence of an especial skill. Significant positive correlations were found for the 11 ft and 17 ft distance, age, years of playing, and accumulated practice hours with performance at the 15 ft line (p<.05). These correlations imply the operation of generalization in the especial skill. This observation received support from applying a model in which shot accuracy as a function of distance was approximated by two regression lines. PMID:23981485

  6. Ten new complete mitochondrial genomes of pulmonates (Mollusca: Gastropoda) and their impact on phylogenetic relationships

    PubMed Central

    2011-01-01

    Background Reconstructing the higher relationships of pulmonate gastropods has been difficult. The use of morphology is problematic due to high homoplasy. Molecular studies have suffered from low taxon sampling. Forty-eight complete mitochondrial genomes are available for gastropods, ten of which are pulmonates. Here are presented the new complete mitochondrial genomes of the ten following species of pulmonates: Salinator rhamphidia (Amphiboloidea); Auriculinella bidentata, Myosotella myosotis, Ovatella vulcani, and Pedipes pedipes (Ellobiidae); Peronia peronii (Onchidiidae); Siphonaria gigas (Siphonariidae); Succinea putris (Stylommatophora); Trimusculus reticulatus (Trimusculidae); and Rhopalocaulis grandidieri (Veronicellidae). Also, 94 new pulmonate-specific primers across the entire mitochondrial genome are provided, which were designed for amplifying entire mitochondrial genomes through short reactions and closing gaps after shotgun sequencing. Results The structural features of the 10 new mitochondrial genomes are provided. All genomes share similar gene orders. Phylogenetic analyses were performed including the 10 new genomes and 17 genomes from Genbank (outgroups, opisthobranchs, and other pulmonates). Bayesian Inference and Maximum Likelihood analyses, based on the concatenated amino-acid sequences of the 13 protein-coding genes, produced the same topology. The pulmonates are paraphyletic and basal to the opisthobranchs that are monophyletic at the tip of the tree. Siphonaria, traditionally regarded as a basal pulmonate, is nested within opisthobranchs. Pyramidella, traditionally regarded as a basal (non-euthyneuran) heterobranch, is nested within pulmonates. Several hypotheses are rejected, such as the Systellommatophora, Geophila, and Eupulmonata. The Ellobiidae is polyphyletic, but the false limpet Trimusculus reticulatus is closely related to some ellobiids. Conclusions Despite recent efforts for increasing the taxon sampling in euthyneuran (opisthobranchs and pulmonates) molecular phylogenies, several of the deeper nodes are still uncertain, because of low support values as well as some incongruence between analyses based on complete mitochondrial genomes and those based on individual genes (18S, 28S, 16S, CO1). Additional complete genomes are needed for pulmonates (especially for Williamia, Otina, and Smeagol), as well as basal heterobranchs closely related to euthyneurans. Increasing the number of markers for gastropod (and more broadly mollusk) phylogenetics also is necessary in order to resolve some of the deeper nodes -although clearly not an easy task. Step by step, however, new relationships are being unveiled, such as the close relationships between the false limpet Trimusculus and ellobiids, the nesting of pyramidelloids within pulmonates, and the close relationships of Siphonaria to sacoglossan opisthobranchs. The additional genomes presented here show that some species share an identical mitochondrial gene order due to convergence. PMID:21985526

  7. Identification of sequestered chloroplasts in photosynthetic and non-photosynthetic sacoglossan sea slugs (Mollusca, Gastropoda)

    PubMed Central

    2014-01-01

    Background Sacoglossan sea slugs are well known for their unique ability among metazoans to incorporate functional chloroplasts (kleptoplasty) in digestive glandular cells, enabling the slugs to use these as energy source when starved for weeks and months. However, members assigned to the shelled Oxynoacea and Limapontioidea (often with dorsal processes) are in general not able to keep the incorporated chloroplasts functional. Since obviously no algal genes are present within three (out of six known) species with chloroplast retention of several months, other factors enabling functional kleptoplasty have to be considered. Certainly, the origin of the chloroplasts is important, however, food source of most of the about 300 described species is not known so far. Therefore, a deduction of specific algal food source as a factor to perform functional kleptoplasty was still missing. Results We investigated the food sources of 26 sacoglossan species, freshly collected from the field, by applying the chloroplast marker genes tufA and rbcL and compared our results with literature data of species known for their retention capability. For the majority of the investigated species, especially for the genus Thuridilla, we were able to identify food sources for the first time. Furthermore, published data based on feeding observations were confirmed and enlarged by the molecular methods. We also found that certain chloroplasts are most likely essential for establishing functional kleptoplasty. Conclusions Applying DNA-Barcoding appeared to be very efficient and allowed a detailed insight into sacoglossan food sources. We favor rbcL for future analyses, but tufA might be used additionally in ambiguous cases. We narrowed down the algal species that seem to be essential for long-term-functional photosynthesis: Halimeda, Caulerpa, Penicillus, Avrainvillea, Acetabularia and Vaucheria. None of these were found in Thuridilla, the only plakobranchoidean genus without long-term retention forms. The chloroplast type, however, does not solely determine functional kleptoplasty; members of no-retention genera, such as Cylindrobulla or Volvatella, feed on the same algae as e.g., the long-term-retention forms Plakobranchus ocellatus or Elysia crispata, respectively. Evolutionary benefits of functional kleptoplasty are still questionable, since a polyphagous life style would render slugs more independent of specific food sources and their abundance. PMID:24555467

  8. High pressure, high-temperature vessel, especially for nuclear reactors

    SciTech Connect

    Mitterbacher, P.; Schoning, J.; Schwiers, H.G.

    1980-09-23

    A pressure vessel susceptible to high temperatures, especially for containment of a nuclear-reactor core, is constituted of a cylindrical shell from a cast material such as cast steel, cast iron or concrete, and is prestressed by vertical cables which extend parallel to generatrices of the shell. Peripheral (Circumferential) prestressing cables are provided around the shell which can be externally insulated. The peripheral tensioning cables are exposed externally of the insulation material and bear upon the shell of the vessel with heatresistant elements of high compressive strength which extend through the external insulation.

  9. La binaria LSS 3074 y su entorno: ?`una nueva asociaci髇 OB?

    NASA Astrophysics Data System (ADS)

    Niemela, V.; Morrell, N.; Corti, M.

    En este trabajo presentamos un nuevo an醠isis orbital de LSS~3074, junto con tipos espectrales y velocidades radiales de estrellas que podr韆n constituir con ella una nueva asociaci髇 OB. La estrella O4f LSS3074 fue descubierta como binaria espectrosc髉ica de corto per韔do y l韓eas dobles por Morrell & Niemela (1990, ASP Conf. Ser. 7, 57). Posteriormente, Haefner et~al.(1994, IBVS 3969) encontraron variaciones fotom閠ricas, estimando una inclinaci髇 orbital entre 50o y 55o. Teniendo en cuenta la importancia de obtener valores emp韗icos para las masas de estrellas O tempranas, y considerando la gran dispersi髇 existente entre los valores observados y su discrepancia con los predichos por los modelos te髍icos, hemos obtenido nuevas observaciones espectrosc髉icas de este sistema, con el prop髎ito de mejorar los elementos orbitales derivados en la soluci髇 preliminar. Adem醩, como las estrellas O tempranas suelen formar parte de c鷐ulos y asociaciones OB, hemos llevado a cabo una investigaci髇 espectrosc髉ica de varias estrellas tempranas que podr韆n estar f韘icamente relacionadas con LSS~3074.

  10. Lecciones sobre el financiamiento de nuevas l韓eas ferroviarias urbanas y suburbanas de pasajeros: El caso de los ferrocarriles de Tokio

    Microsoft Academic Search

    Jorge Kohon

    2011-01-01

    Los ferrocarriles urbanos y suburbanos en las grandes ciudades no cubren con sus ingresos propios los costos de capital y, usualmente, tampoco cubren los costos de operaci髇. Este estado de cosas requiere nuevas alternativas de financiamiento que contribuyan a disminuir el \\

  11. DEVELOPMENT OF A SUSTAINABLE AND APPROPRIATE DRINKING WATER SYSTEM FOR MONTANA DE LUZ AND NUEVA ESPERANZA, HONDURAS

    EPA Science Inventory

    In this project, we plan to design an appropriate and sustainable water treatment and supply system for a small village (Nueva Esperanza) and nearby orphanage in rural Honduras. The orphanage, named 揗ontana de Luz, is a home exclusively for children with HIV/A...

  12. Megafauna recovered from a cold hydrocarbon seep in the deep Alaskan Beaufort Sea, including a new species of Axinus (Thracidae: Bivalvia: Mollusca)

    NASA Astrophysics Data System (ADS)

    Powell, C. L.; Valentich-Scott, P.; Lorenson, T. D.; Edwards, B. D.

    2011-12-01

    Several specimens of a new species of Axinus and a single well-worn gastropod columella provisionally assigned to the genus Neptunea (Buccinidae: Gastropoda: Mollusca) were recently recovered from at least two cores, the longest of which is 5.72 m long, from a large seafloor mound, informally named the Canning Seafloor Mound (CSM). The CSM is located at 2,530 m water depth on the Alaskan Beaufort Sea slope north of Camden Bay and is a fluid explosion feature containing methane hydrate and methane-saturated sediments overlying a folded and faulted deep basin. Only two modern species of Axinus are currently known. Axinus grandis (Verrill & Smith, 1885) is a northern Atlantic species and the recently described species, A. cascadiensis Oliver and Holmes (2007), is only known from Baby Bare Seamount, Cascadia Basin, northeastern Pacific Ocean. Common fragments, single valves, and a single articulated specimen represent this new Axinus species. These shells were distributed over nearly the entire length of the primary core. All specimens show wear and (or) dissolution. The age of these specimens is unknown and no living representatives were encountered. The genus Axinus has a fossil record back to the early Eocene in England and the Paleocene and Eocene in Egypt. Biogeographically the genus appears to have originated in the Tethys Sea and became established in the Atlantic Ocean during the Eocene, spreading across the Arctic Ocean in the late Tertiary. With the opening of the Bering Strait in the latest Miocene or early Pliocene the genus Axinus migrated southwest into the northeast Pacific. Interestingly, hydrocarbon seep deposits are also present on the adjacent North Slope of Alaska in the Marsh Anticline at Carter Creek, Camden Bay. These rocks, the Nuwok beds, contain abundant Thracidae bivalve of the genus Thracia, but not Axinus, however the rocks also represent cold seep deposits. These rocks have been variously dated from Oligocene to Pliocene and the exact age remains uncertain. Neptunea are a predatory snails well represented in the earliest Miocene to Holocene of the northern Pacific Ocean and in the late Pliocene to Holocene of the northern Atlantic. The presence of Neptunea at CSM, if identified properly, gives a maximum age for these deposits of latest Miocene or early Pliocene, after the opening of the Bering Strait, although they could be as young as Holocene.

  13. 6 Polmeros: Cincia e Tecnologia -Out/Dez -99 Edio Especial

    E-print Network

    Ferreira, M醨cia M. C.

    6 Pol韒eros: Ci阯cia e Tecnologia - Out/Dez - 99 E D I T O R I A L Edi玢o Especial O 5o Congresso n鷐ero especial da revista "Pol韒eros: Ci阯cia e Tecnologia". Ap髎 a sele玢o prelimi- nar de 100 deles, com a especial colabora玢o do Comit Editorial da revista "Pol韒eros: Ci阯cia e Tecnologia" na

  14. Procesos de precipitaci髇 mineral bioinducidos en sistemas k醨sticos subterr醤eos: breve revisi髇 y nuevas tendencias

    Microsoft Academic Search

    S. S醤chez-Moral; J. M. Gonz醠ez; J. C. Ca馻veras; S. Cuezva; J. Lario; C. Cardell; J. Elez; L. Luque; C. Saiz-Jim閚ez

    Microorganisms, particularly bacteria, inhabit all possible environments in the biosphere including subterranean ones. They play an important role in geological processes such as mineral precipitation and dissolution, and significantly influence biogeochemical cycles. At present, relatively few studies have focused on the active role of microorganisms, especially bacteria, in the formation of speleothems. Thus, the involvement of microbial activity in the

  15. Prescripci髇 electr髇ica asistida como nueva tecnolog韆 para la seguridad del paciente hospitalizado

    Microsoft Academic Search

    Elena Villama襻n; Alicia Herrero; Rodolfo 羖varez-Sala

    2011-01-01

    Concern about patient safety is a priority in the quality policy of health systems. In the pharmacotherapeutic process, from prescription to administration of drugs, failures that cause unwanted effects in patients may occur. This is especially common in patients with multiple pathologies and polypharmacy, common in medical specialities services. To analyze and identify the causes that trigger medical errors is

  16. ARQUITECTURA FOLIAR Y OTROS CARACTERES DEL ESPOR覨ITO EN ESPECIES NEOTROPICALES DE MARATTIA SW. (MARATTIACEAE-PTERIDOPHYTA)

    Microsoft Academic Search

    Mar韆 del Carmen LAVALLE

    RESUMEN. Arquitectura foliar y otros caracteres del espor骹ito en especies neotropicales de Marattia Sw., Marattiaceae-Pteridophyta. Se estudi la arquitectura foliar y la anatom韆 de ejes y l醡inas en siete especies neotropicales de Marattia: M. alata Sw., M. cicutifolia Kaulf., M. excavata Underw., M. interposita H. Christ, M. laevis Sm., M. laxa Kunze y M. weinmanniifolia Liebm. Los rizomas desnudos, amil醕eos,

  17. Board Practices of Especially Effective and Less Effective Local Nonprofit Organizations

    Microsoft Academic Search

    Robert D. Herman; David O. Renz

    2000-01-01

    This study reviews evidence in support of the hypothesis that nonprofit organizations抏ffectiveness is related to the effectiveness of their boards of directors. It also asks whether various recommended board practices and processes affect board effectiveness. The study focuses on a subset of especially effective and less effective nonprofit organizations from a larger sample. The results show that the especially effective

  18. REGLAMENT DEL CENTRE ESPECIAL DE RECERCA INSTITUT DE DRET I TECNOLOGIA DE LA UAB (IDT)

    E-print Network

    Aut貌noma de Barcelona, Universitat

    1 REGLAMENT DEL CENTRE ESPECIAL DE RECERCA INSTITUT DE DRET I TECNOLOGIA DE LA UAB (IDT) Acord del.- Denominaci贸 i finalitat L'Institut de Dret i Tecnologia (IDT), 茅s un Centre Especial de Recerca, creat de de 1995. Article 2.- R猫gim jur铆dic L'Institut de Dret i Tecnologia es regeix per aquest Reglament

  19. Investigaci髇 translacional para generar datos a favor de la introducci髇 racional y eficiente de vacunas nuevas en pa韘es en v韆s de desarrollo: La experiencia del Instituto Internacional de Vacunas

    Microsoft Academic Search

    John Clemens

    2008-01-01

    ExtractoEn los 鷏timos a駉s, la introducci髇 de vacunas nuevas en pa韘es opulentos ha tenido lugar a un ritmo asombroso. En comparaci髇, se han introducido pocas vacunas de nueva generaci髇 en los programas de salud p鷅lica para los pobres de los pa韘es en v韆s de desarrollo, y para aqu閘los que s los tienen, la introducci髇 ha sido penosamente lenta. Los recursos

  20. Historical developments of hydrothermal works in Japan, especially in ceramic science

    Microsoft Academic Search

    S. Somiya

    2006-01-01

    Historical developments of hyrothermal works especially hydrothermal synthesis and hydrothermal corrosion in Japan are described.\\u000a And also, some major activities of important Japanese researchers are given.

  1. The use of spectroscopic techniques (especially phosphorus-31 nuclear magnetic resonance [31

    E-print Network

    Sparks, Donald L.

    1617 The use of spectroscopic techniques (especially phosphorus-31 nuclear magnetic resonance [31 P; Shober et al., 2006; Toor et al., 2005a, 2005b) and solid-state phosphorus-31 nuclear magnetic resonance

  2. Bad Flu Season Continues to Take Toll, Especially Among the Young and Old

    MedlinePLUS

    ... features on this page, please enable JavaScript. Bad Flu Season Continues to Take Toll, Especially Among the ... and Old Not too late to get a flu shot, health officials say; antiviral meds strongly recommended (* ...

  3. a-Synuclein, Especially the Parkinson's Disease-associated Mutants, Forms Pore-like Annular and

    E-print Network

    Walz, Thomas

    a-Synuclein, Especially the Parkinson's Disease- associated Mutants, Forms Pore-like Annular early-onset Parkinson's disease (PD). Both mutations promote the formation of transient protofibrils rights reserved Keywords: a-synuclein; Parkinson's disease; protofibrils; transmission electron

  4. University of Connecticut Theory-based approaches to social issues, especially prejudice, inequality, health.

    E-print Network

    Alpay, S. Pamir

    behavior change. In addition, his research on prosocial behavior has been psychology, and more specifically promoting health behavior, especially HIV risk, crowding, and nonverbal behavior. Another focus includes people's reactions to change

  5. Especial skill effect across age and performance level: the nature and degree of generalization.

    PubMed

    Czy?, S H; Breslin, G; Kwon, O; Mazur, M; Kobia?ka, K; Pizlo, Z

    2013-01-01

    It has been claimed that an especial skill emerges after massive amounts of basketball practice. Despite this no direct evidence is available to support this claim. The authors aimed to shed light on this question. Thirty-seven male basketball players took part representing four groups: 2 groups of senior players, a cadet group, and a group of juniors. Players performed free throw shots from 7 distances including shots from the free throw line (15 ft). It was shown that an especial skill was present in senior players, but not in junior players who had only 3 years of playing experience. The authors present a descriptive model of especial skill and express it using the formalism of a hierarchical Bayesian model to fit the data and estimate the parameters. This model can account not only for the results, which indicate the presence and a substantial degree of generalizability of especial skill to nearby distances, but also for results of the original study on especial skill where it was proposed that specificity in practice leads to the emergence of the especial skill. PMID:23488624

  6. EVALUACI覰 DEL ACUERDO DE NUEVA IMPERIAL Y SU IMPACTO EN LA REALIDAD IND虶ENA CHILENA, DESDE LA PERCEPCI覰 DE LA DIRIGENCIA AYMARA1

    Microsoft Academic Search

    Ren Patricio; Aguilera Barraza

    This paper is a review of the way in which the Agreement of Nueva Imperial impacted in the Chilean indigenous scenario, from the critical perception of the aymara leadership. The protocol was signed in 1989, between the pre-Columbian groups (Mapuche, Rapa Nui, Kolla, Atacame駉 and Aymara) and the political parties opposed against the dictatorship of Augusto Pinochet Ugarte. According to

  7. El PIB de la rep鷅lica de la Nueva Granada en 1846: 縌u nos dice acerca del impacto econ髆ico de la independencia?

    Microsoft Academic Search

    Adolfo Meisel Roca

    2011-01-01

    En este trabajo se hace un c醠culo del producto interno bruto, PIB, de la Rep鷅lica de Nueva Granada en 1846. As mismo, para ese a駉 tambi閚 se presenta la estructura del empleo, clasificado por las principales ocupaciones, y la composici髇 y valor de la riqueza material. Para ello nos basamos en un censo econ髆ico nacional realizado en 1846 y que

  8. Environmental geochemistry on La Nueva Concepci髇 mercury mining area, a comparison with the metallurgical complex of Almadenejos.

    NASA Astrophysics Data System (ADS)

    Castillo, Washington; Herrera, Edison; Mart韓ez-Coronado, Alba; Oyarzun, Roberto; Higueras, Pablo; Mar韆 Esbr, Jos

    2014-05-01

    Almadenejos is a small town located some 14 km East of Almad閚, and was the main mining and metallurgical complex of an area comprising the Vieja Concepci髇 (1699-1800), Nueva Concepci髇 (1794-1965), and El Entredicho (Middle Age s.l., and 1981-1997) mines as well as the old Almadenejos metallurgical precinct (1700?-1860). This combination makes the area one of the most contaminated in the Almad閚 district. This study covers the Nueva Concepci髇 mine area, a sector that lacked geochemical data before this study. We here present the results of a survey including soils (n = 80), lichens (Evernia prunastri) (n = 73) and total gaseous mercury (n = 61). The analyses of soils and lichens were carried out using an atomic absorption spectrometer AMA254, while total gaseous mercury determinations were in-situ obtained using a portable Lumex RA-915+. We used Surfer 8 for the krigging and subsequent mapping of geochemical data. Mercury contents in soils are in the range of 6 - 721 mg kg-1, clearly higher than critical concentrations in soils by Kabata-Pendias (2001) (0.3 - 5 mg kg-1). This mercury levels are higher in the metallurgical facility of Almadenejos (range = 25 - 15900 mg kg-1), putting forward that the main pollution legacy relates to the metallurgical activities and not to the mining operations. The statistical distribution of data is log-normal and as shown by the krigging Hg shows a remarkable E-W spatial component which closely matches the structural pattern of the main Hg hosting bed: the Criadero Quartzite. On the other hand, total gaseous mercury shows a WNW-ESE tendency most probably controlled by the local main wind direction. A similar spatial trend was found for the lichen's Hg contents. Mercury contents in these lichens are 103 times higher than in pristine areas but lower than those from the abandoned (and highly polluted) Almadenejos metallurgical complex.

  9. vol. 164, no. 6 the american naturalist december 2004 Cooperation and Punishment, Especially in Humans

    E-print Network

    Gardner, Andy

    vol. 164, no. 6 the american naturalist december 2004 Cooperation and Punishment, Especially recently received much attention is the threat of punishment. However, punishing behavior is often costly for the punisher, and so it is not immediately clear how costly punishment could evolve. We use a direct (neighbor

  10. 1 INTRODUCTION Especially in arid or semi-arid areas, such as Central

    E-print Network

    Bolch, Tobias

    , glaciers retreat and permafrost degradation in Central Asia, the ground ice could increase future water1 INTRODUCTION Especially in arid or semi-arid areas, such as Central Asia, the mountains have to the water/ice content of permafrost and glaciers. Therefore it is important to study their reaction

  11. Training for Emergencies Need for some uniformity of training across airlines. Concern is especially about

    E-print Network

    Training for Emergencies 路 Need for some uniformity of training across airlines. Concern is especially about variability in amount of training for emergencies. Not enough training in general for emergencies. 路 What are the criteria for training for success. 路 Try a "hypertext" approach to simulator

  12. International Freight Flow Modeling considering Cross-Border Transport Especially Focused in Mekong River Area

    Microsoft Academic Search

    Ryuichi SHIBASAKI; Liqiang MA; Hitoshi IEDA; Lixin MIAO

    Until now, authors have developed an international freight flow model which is mainly focused on international maritime transport but also including domestic transport network in Japan and China. By using this model, international freight transport policy such as port investment as well as improvement of connection between port and road in each country of Asia, especially focused on Japan and

  13. 1999 Macmillan Magazines Ltd especially as the fully reduced enzyme is out

    E-print Network

    Braun, Paul

    漏 1999 Macmillan Magazines Ltd especially as the fully reduced enzyme is out of electrostatic translocation by cytochrome c oxidase seems to be coup- led to the enzyme's oxidative catalytic half- cycle1 reported the release of 1颅2 H+ . This variation is due to the difficulty of having all the enzyme molecules

  14. Visualizing Vocal Expression Sound, especially speech, is ephemeral. It is a high-

    E-print Network

    Karahalios, Karrie G.

    Visualizing Vocal Expression Abstract Sound, especially speech, is ephemeral. It is a high- speed communication is ephemeral. After the sound fades away, it lives only in fallible, limited, mutable memory collected, absorbed, expanded, and recombined ideas, without the presence of the original speaker

  15. Abstract--This paper presents ambient mechanical vibrations as an alternative source for energy harvesting, especially

    E-print Network

    Kumar, Ratnesh

    Abstract--This paper presents ambient mechanical vibrations as an alternative source for energy harvesting, especially beneficial where alternatives such as light, wind, biomass and thermal energy are limited, e.g., powering underground sensors. Transduction of ambient kinetic energy, e.g., the vibrations

  16. Insect-Plant Interactions Insects & Plants Evolution of land plants (especially

    E-print Network

    Brown, Christopher A.

    ) a major force driving the diversity of insects As diversity of land plants has increased, the diversity1 Insect-Plant Interactions Insects & Plants Evolution of land plants (especially flowering plants of insects has increased Interaction between plants and insects is an example of coevolution Coevolution

  17. region next to the plastid body, especially if the tubules encircle other organelles such as

    E-print Network

    Malinow, Roberto

    region next to the plastid body, especially if the tubules encircle other organelles similar to the color observed by eye with the Olympus microscope was added to the images by the import of data collected in the green and red channels from the BioRad mi- croscope into Adobe Photoshop. Optical

  18. Busy moms--especially young moms--are also frustrated by the flood of changing nutrition

    E-print Network

    Burke, Peter

    Busy moms--especially young moms--are also frustrated by the flood of changing nutrition advice when it comes to their children's eating habits. The top concern, shared by more than four-in-10 moms improve your children's food habits since kids tend to eat more fruits, vegetables and dairy foods

  19. All life transitions offer both opportunities and challenges--especially so for youth as they transition

    E-print Network

    Sarkar, Nilanjan

    is searching for answers to that critical question. "We don't know what clock mechanism signals that it is timeAll life transitions offer both opportunities and challenges--especially so for youth attended "Life Skills" classrooms. The intervention occurred in school cafeterias, gymnasiums, hallways

  20. Challenges to Cognitive Bases for an Especial Motor Skill at the Regulation Baseball Pitching Distance

    ERIC Educational Resources Information Center

    Simons, Jeffery P.; Wilson, Jacob M.; Wilson, Gabriel J.; Theall, Stephen

    2009-01-01

    We tested expert baseball pitchers for evidence of especial skills at the regulation pitching distance. Seven college pitchers threw indoors to a target placed at 60.5 feet (18.44 m) and four closer and four further distances away. Accuracy at the regulation distance was significantly better than predicted by regression on the nonregulation

  1. Intragenomic sequence variation at the ITS1 - ITS2 region and at the 18S and 28S nuclear ribosomal DNA genes of the New Zealand mud snail, Potamopyrgus antipodarum (Hydrobiidae: mollusca)

    USGS Publications Warehouse

    Hoy, Marshal S.; Rodriguez, Rusty J.

    2013-01-01

    Molecular genetic analysis was conducted on two populations of the invasive non-native New Zealand mud snail (Potamopyrgus antipodarum), one from a freshwater ecosystem in Devil's Lake (Oregon, USA) and the other from an ecosystem of higher salinity in the Columbia River estuary (Hammond Harbor, Oregon, USA). To elucidate potential genetic differences between the two populations, three segments of nuclear ribosomal DNA (rDNA), the ITS1-ITS2 regions and the 18S and 28S rDNA genes were cloned and sequenced. Variant sequences within each individual were found in all three rDNA segments. Folding models were utilized for secondary structure analysis and results indicated that there were many sequences which contained structure-altering polymorphisms, which suggests they could be nonfunctional pseudogenes. In addition, analysis of molecular variance (AMOVA) was used for hierarchical analysis of genetic variance to estimate variation within and among populations and within individuals. AMOVA revealed significant variation in the ITS region between the populations and among clones within individuals, while in the 5.8S rDNA significant variation was revealed among individuals within the two populations. High levels of intragenomic variation were found in the ITS regions, which are known to be highly variable in many organisms. More interestingly, intragenomic variation was also found in the 18S and 28S rDNA, which has rarely been observed in animals and is so far unreported in Mollusca. We postulate that in these P. antipodarum populations the effects of concerted evolution are diminished due to the fact that not all of the rDNA genes in their polyploid genome should be essential for sustaining cellular function. This could lead to a lessening of selection pressures, allowing mutations to accumulate in some copies, changing them into variant sequences.

  2. An example of the application of geometric morphometric tools to the morphological diagnosis of two sibling species

    E-print Network

    Carvajal-Rodr铆guez, Antonio

    sibling species in Nassarius (Mollusca, Prosobranchia) Un ejemplo de aplicaci贸n de la herramienta de morfometr铆a geom茅trica en el diagn贸stico morfol贸gico de dos especies gemelas en Nassarius (Mollusca

  3. CADERNOS TEMTICOS QUMICA NOVA NA ESCOLA Edio especial FEVEREIRO 2001 ste volume dedicado qumica

    E-print Network

    Jardim, Wilson de Figueiredo

    3 CADERNOS TEM脕TICOS 颅 QU脥MICA NOVA NA ESCOLA Edi莽茫o especial 颅 FEVEREIRO 2001 E ste volume 茅 uma nova ordem. A informa莽茫o transformou nos- so planeta em um sis- tema 煤nico, interli- gado. Quando a avalia莽茫o de risco ambiental, com o risco de exposi- 莽茫o 脿s novas mol茅culas produzidas pelo homem, das quais

  4. El Instituto Nacional del C醤cer (NCI) anuncia su nueva pol韙ica de reuniones libres de humo de tabaco para abordar peligros graves de salud p鷅lica

    Cancer.gov

    El Instituto Nacional del C醤cer (NCI), que forma parte de los Institutos Nacionales de la Salud, anunci hoy una nueva pol韙ica que requiere que todas las reuniones y conferencias organizadas o financiadas principalmente por el NCI se lleven a cabo en un estado, condado, ciudad o pueblo que haya adoptado una pol韙ica integral de ambientes libres de humo de tabaco, a menos que circunstancias especificas justifiquen la exenci髇.

  5. Cyanobacteria\\/Foraminifera Association from Anoxic\\/Dysoxic Beds of the Agua Nueva Formation (Upper Cretaceous - Cenomanian\\/Turonian) at Xilitla, San Luis Potosi, Central Mexico

    Microsoft Academic Search

    A. Blanco-Pi耋n; F. J. Maurrasse; A. Rojas-Le髇; F. Duque-Botero

    2008-01-01

    The Agua Nueva Formation in the vicinity of Xilitla, State of San Luis Potos, Central Mexico, consists of interbedded brown shale (Grayish orange 10YR 7\\/4 to Moderate yellowish brown 10YR 5\\/4) and dark-gray fossiliferous limestone (Bluish gray 5B 6\\/1 to Dark bluish gray 5B 4\\/1), varying between 10 and 20 cm in thickness. The sequence also includes 2 to 4

  6. The Arctic is especially sensitive to black carbon emissions from within the region

    NASA Astrophysics Data System (ADS)

    Sand, M.; Berntsen, T.; Seland; Kristjansson, J.

    2013-12-01

    The Arctic has warmed twice as fast as the global average over the past century and is likely to be especially sensitive to black carbon aerosols. Black carbon warm the air by absorbing solar radiation and can promote snow melt when deposited in snow. In this study we address the question of how sensitive the Arctic climate is to black carbon emitted within the Arctic compared to black carbon emitted at mid-latitudes. We consider the emission-climate response spectrum and present a set of experiments using a coupled global climate model. The climate model includes a snow model to simulate the climate effect of BC deposited on snow. A new emission data set including BC emissions from flaring and a seasonal variation in the domestic sector has been used. The dominating BC emissions in the Arctic is related to oil and gas fields in north western Russia. We find that most of the BC-induced warming in the Arctic is caused by black carbon deposited on snow, rather than in the atmosphere. Black carbon emitted in the Arctic is more likely to get deposited at the surface since most of the concentrations stay at lower altitudes. Especially during winter, BC emitted in North-Eurasia is transported into the high Arctic at low altitudes. We find that BC emitted within the Arctic has an almost 5-times larger Arctic surface temperature response (per unit of emitted mass) compared to emissions at mid-latitudes. Today there are few within-Arctic sources of BC, but the emissions are expected to grow due to increased human activity in the Arctic. There is a great need to improve cleaner technologies if further development is to take place in the Arctic, especially since the Arctic has a significantly higher sensitivity to BC emitted within the Arctic compared to BC emitted at mid-latitudes.

  7. Highly efficient tetradentate ruthenium catalyst for ester reduction: especially for hydrogenation of fatty acid esters.

    PubMed

    Tan, Xuefeng; Wang, Yan; Liu, Yuanhua; Wang, Fangyuan; Shi, Liyang; Lee, Ka-Ho; Lin, Zhenyang; Lv, Hui; Zhang, Xumu

    2015-02-01

    A new tetradentate ruthenium complex has been developed for hydrogenation of esters. The catalyst's structure features a pyridinemethanamino group and three tight chelating five-membered rings. The structure character is believed to be responsible for its high stability and high carbonylation-resistant properties. Thus, this catalyst shows outstanding performance in the catalytic hydrogenation of a variety of esters, especially for fatty acid esters, which may be used in practical applications. New insight on designing hydrogenation catalyst for reducing esters to alcohols has been provided through theoretical calculations. PMID:25582610

  8. The Present Status of Airship Construction, Especially of Airship-framing Construction

    NASA Technical Reports Server (NTRS)

    Ebner, Hans

    1938-01-01

    This work proposes to sketch, in broad outline, the status of airship construction in the various countries, at a time when commerce over great distances might be finally opened up to the airship through the performances of the "Graf Zeppelin." After a short historical review, a survey of the most important rigid and semirigid airships built since 1925, their differences and special problems, is made. In more detailed treatment, the framing construction of the more recent rigid airships and some especially interesting structural questions are investigated.

  9. Molecular resolution of the family Dreissenidae (Mollusca: Bivalvia) with emphasis on Ponto-Caspian species, including first report of Mytilopsis leucophaeata in the Black Sea basin

    Microsoft Academic Search

    Thomas W. Therriault; Margaret F. Docker; Marina I. Orlova; Daniel D. Heath; Hugh J. MacIsaaca

    2004-01-01

    Considerable uncertainty exists in determination of the phylogeny among extant members of the Dreissenidae, especially those inhabiting the Ponto-Caspian basin, as multiple systematic revisions based on morphological characteristics have failed to resolve relationships within this group of bivalves. In this study we use DNA sequence analyses of two mitochondrial gene fragments, 16S rRNA and cytochrome c oxidase subunit I (COI),

  10. The history of assisted human conception with especial reference to endocrinology.

    PubMed

    Edwards, R G

    1996-01-01

    This review lecture is primarily concerned with the study of assisted human conception and especially in-vitro fertilization (IVF). It also places in perspective the role of endocrinology in history of IVF. A knowledge of the hypothalamic-pituitary control of ovulation, and of ovarian follicle dynamics is assumed. A detailed consideration of these topics, together with extensive references, are available in a recent textbook (Edwards and Brody, 1995). Many of the early pioneers studying animal reproduction combined reproductive physiology and endocrinology, especially Marshall, who analysed oestrous and menstrual cycles in many mammalian species. The clarification of the roles of pituitary gland and hypothalamus in the menstrual cycle and ovulation, and their regulation by steroidal feedbacks from the gonads gave an immense stimulus to studies on human reproduction (Smith and Engle, 1927; Lewis and Gregory, 1933; Harris, 1970). Three periods of research into assisted human conception are covered in this lecture including the initial work on the introduction of the endocrinology and embryology of human IVF, the rapid advances in technique as it expanded worldwide, and finally some of the recent remarkable advances in the field. PMID:8817236

  11. Exposure limits: the underestimation of absorbed cell phone radiation, especially in children.

    PubMed

    Gandhi, Om P; Morgan, L Lloyd; de Salles, Alvaro Augusto; Han, Yueh-Ying; Herberman, Ronald B; Davis, Devra Lee

    2012-03-01

    The existing cell phone certification process uses a plastic model of the head called the Specific Anthropomorphic Mannequin (SAM), representing the top 10% of U.S. military recruits in 1989 and greatly underestimating the Specific Absorption Rate (SAR) for typical mobile phone users, especially children. A superior computer simulation certification process has been approved by the Federal Communications Commission (FCC) but is not employed to certify cell phones. In the United States, the FCC determines maximum allowed exposures. Many countries, especially European Union members, use the "guidelines" of International Commission on Non-Ionizing Radiation Protection (ICNIRP), a non governmental agency. Radiofrequency (RF) exposure to a head smaller than SAM will absorb a relatively higher SAR. Also, SAM uses a fluid having the average electrical properties of the head that cannot indicate differential absorption of specific brain tissue, nor absorption in children or smaller adults. The SAR for a 10-year old is up to 153% higher than the SAR for the SAM model. When electrical properties are considered, a child's head's absorption can be over two times greater, and absorption of the skull's bone marrow can be ten times greater than adults. Therefore, a new certification process is needed that incorporates different modes of use, head sizes, and tissue properties. Anatomically based models should be employed in revising safety standards for these ubiquitous modern devices and standards should be set by accountable, independent groups. PMID:21999884

  12. Inappropriate management conditions, especially for the regressed class, are related to sperm quality in Prochilodus lineatus.

    PubMed

    De Souza, Thiago G; Hainfellner, Patrick; Kuradomi, Rafael Y; Mu駉z, Mario E; Honji, Renato M; Moreira, Renata G; Batlouni, Sergio R

    2015-03-15

    The aims of this study were to evaluate the characteristics of the reproductive classes and semen quality in curimbat (Prochilodus lineatus) breeders maintained in two different rearing systems. To achieve this goal, cages (Cs) and earthen ponds (EPs) were used as experimental systems to provide unsuitable and suitable conditions, respectively. The fish were maintained under the experimental conditions for 18爉onths. During this period, males were randomly sampled every 2爉onths for biometric analysis (n=30 per sample) and for an evaluation of selected characteristics of the testes (n=5 per sample). After this period, males maintained in EPs and males maintained in Cs (CMs) were evaluated in induced breeding experiments. We observed that rearing P. lineatus in a C at a high stocking density for the long 18-month period of study produced reductions in growth, testis development, gonadosomatic index values, and sperm quality in the fish. We found differences between the groups in all the reproductive classes examined, especially in the regression class, which showed a pronounced accumulation of immature germ cells in the CMs. In this group, we also noted a less intense transition from a continuous to discontinuous germinal epithelium, with an extended and abnormal but less intense spermatogenic period resulting in decreases in semen volume and sperm concentration in the breeding season. Together, such dysfunctions resulted in the production of low-quality sperm in the CMs, as demonstrated by lower-quality DNA (as evaluated by the comet assay), low fertilization success, and low hatching success. In conclusion, to ensure high-quality semen in P. lineatus, appropriate management conditions must be provided throughout the reproductive cycle, especially for the regressed class, even in winter, two seasons before the breeding season. PMID:25515362

  13. Iron-binding compounds impair Pseudomonas aeruginosa biofilm formation, especially under anaerobic conditions.

    PubMed

    O'May, Che Y; Sanderson, Kevin; Roddam, Louise F; Kirov, Sylvia M; Reid, David W

    2009-06-01

    The success of Pseudomonas aeruginosa in cystic fibrosis (CF) and other chronic infections is largely attributed to its ability to grow in antibiotic-resistant biofilm communities. This study investigated the effects of limiting iron levels as a strategy for preventing/disrupting P. aeruginosa biofilms. A range of synthetic and naturally occurring iron-chelating agents were examined. Biofilm development by P. aeruginosa strain PAO1 and CF sputum isolates from chronically infected individuals was significantly decreased by iron removal under aerobic atmospheres. CF strains formed poor biofilms under anaerobic conditions. Strain PAO1 was also tested under anaerobic conditions. Biofilm formation by this model strain was almost totally prevented by several of the chelators tested. The ability of synthetic chelators to impair biofilm formation could be reversed by iron addition to cultures, providing evidence that these effective chelating compounds functioned by directly reducing availability of iron to P. aeruginosa. In contrast, the biological chelator lactoferrin demonstrated enhanced anti-biofilm effects as iron supplementation increased. Hence biofilm inhibition by lactoferrin appeared to occur through more complex mechanisms to those of the synthetic chelators. Overall, our results demonstrate the importance of iron availability to biofilms and that iron chelators have potential as adjunct therapies for preventing biofilm development, especially under low oxygen conditions such as encountered in the chronically infected CF lung. PMID:19429753

  14. Seasonal variability of meiofauna, especially harpacticoid copepods, in Posidonia oceanica macrophytodetritus accumulations

    NASA Astrophysics Data System (ADS)

    Mascart, Thibaud; Lepoint, Gilles; Deschoemaeker, Silke; Binard, Marc; Remy, Fran鏾is; De Troch, Marleen

    2015-01-01

    The overall aim of this study was (1) to assess the diversity and density of meiofauna taxa, especially harpacticoid copepod species, present within accumulated seagrass macrophytodetritus on unvegetated sand patches and (2) to elucidate the community structure of detritus-associated harpacticoid copepods in relation to natural temporal variability of physico-chemical characteristics of accumulations. This was investigated in a Posidonia oceanica (L.) Delile seagrass ecosystem in the northwest Mediterranean Sea (Bay of Calvi, Corsica, 4235?N, 843?E) using a triplicate macrophytodetritus core field sampling in two contrasting sites over the four seasons of 2011. Meiofauna higher taxa consisted of 50% Copepoda, of which 87% belonged to the Harpacticoida order. Nematoda was the second most abundant taxa. The copepod community displayed a wide variety of morphologically similar and ecologically different species (i.e. mesopsammic, phytal, phytal-swimmers, planktonic and parasitic). The harpacticoid copepod community followed a strong seasonal pattern with highest abundances and species diversity in May-August, revealing a link with the leaf litter epiphyte primary production cycle. Aside from the important role in sheltering, housing and feeding potential of macrophytodetritus, a harpacticoid community BEST analysis demonstrated a positive correlation with habitat complexity and a negative correlation with water movements and P. oceanica leaf litter accumulation.

  15. Etologia aplicada al manejo de especies amenazadas: el caso del turon de patas negras (Mustela nigripes)

    USGS Publications Warehouse

    Vargas, A.; Biggins, D.; Miller, B.

    1999-01-01

    de esta especie de un modo m醩 eficaz y rentable. Black-footed ferrets are considered one of the world's most endangered mammals. The last wild population was discovered in 1981 in Meteetsee, Wyoming, and, in 1985 it collapsed due to an epizootic of canine distemper in combination with sylvatic plague. Prior to the extinction of the last remnant population, 18 wild black-footed ferrets were captured to initiate captive propagation efforts. Captive breeding has been successful and, during the last 11 years, more than 2600 black-footed ferrets have been born in captive breeding centers. Since 1991, approximately 870 ferrets have been reintroduced in 5 areas located within the ferret's original geographic distribution, including sites in Wyoming, Montana, South Dakota, and Arizona. Scientific research has been, and continues to be, a critical tool to direct recovery efforts. Studies in applied ethology conducted on captive and reintroduced ferret populations have demonstrated that a naturalistic captive environment, particularly during early developmental periods, enhances the expression of behaviors necessary for survival in nature. Ferrets raised in a naturalistic environment develop better predatory skills, are able to recognize prairie dog burrows as a home and shelter from predators, and are more physically fit. Results from these studies have been adapted into management strategies to help implement a more cost-effective road to black-footed ferret recovery.

  16. Nitrogen-doped porous carbons by conversion of azo dyes especially in the case of tartrazine

    NASA Astrophysics Data System (ADS)

    Zhang, Zhong Jie; Chen, Chong; Cui, Peng; Chen, Xiang Ying

    2013-11-01

    Nitrogen-doped porous carbons possessing high surface areas and large pore volumes have been prepared by directly heating the mixture of tartrazine and Ca(OAc)2稨2O at 800 癈 especially without further physical or chemical activation, where Ca(OAc)2稨2O serves as the hard template to regulate the surface area and pore structures. It reveals that the addition of Ca(OAc)2稨2O can remarkably improve the surface area and total pore volume. The T-Ca-800-3:1 sample displays the highest BET surface area as 1669 m2 g-1 and largest total pore volume 0.85 cm3 g-1, which is much larger than those without adding Ca(OAc)2稨2O. Furthermore, it exhibits excellent capacitive performances, including high specific capacitance (ca. 224.3 F g-1 at 0.5 A g-1), good rate capability (the retention of 42.6% at 60 A g-1) and good cycling stability (the retention of 92.3% within 5000 cycles).

  17. Low molecular weight heparin improves healing of chronic venous ulcers especially in the elderly.

    PubMed

    Serra, Raffaele; Buffone, Gianluca; Molinari, Vincenzo; Montemurro, Rossella; Perri, Paolo; Stillitano, Domenico M; Amato, Bruno; de Franciscis, Stefano

    2015-04-01

    Venous ulcers are common, especially in the elderly, accounting for more than 50% of all lower extremity ulcers with important socioeconomic problems. Improving extracellular matrix functioning, by heparin administration, seems to be a way to support wound healing. A total of 284 patients with venous ulcers were recruited in a 4-year period. All patients were subjected to the most appropriate treatment after considering their preference (compression therapy followed or not by vein surgery). Patients were randomised into two groups of 142 persons in each (group A and group B as cases and controls, respectively). Patients of group A, in addition to the basic treatment as described earlier, received administration of nadroparin 2850?IU/0.3?ml through subcutaneous injection once a day for 12?months, whereas group B patients received basic treatment alone. Healing was assessed by means of direct ulcer tracing with computerised planimetry. Group A showed a healing rate of 8380% at 12?months, whereas that of group B was 6056%. Results by age group surprisingly showed that the group of older patients took the most advantage from long-term treatment with low molecular weight heparin; this group also had lowest recurrence rate. PMID:23517508

  18. On the Chemical Synthesis and Physical Properties of Iron Pyrite, Especially the (100) Surface

    NASA Astrophysics Data System (ADS)

    Macpherson, Hector Alexander

    Given that iron pyrite (cubic FeS2, fool's gold) is a semiconductor with a 1 eV band gap, it has long been investigated for use in technological applications, especially photovoltaics. Unfortunately, numerous measurements indicate that it's properties, as currently synthesized at least, do not allow for effective devices. Photovoltages far below theoretical expectation are found as well as below band gap optical absorption. From a scientific standpoint, our understanding of the cause of these observations, the form of the density of states for instance, remains mired in uncertainty. In this work we have attempted to gain insight into this problem by creating ensembles of pyrite nanocrystals that can then be treated and measured with well-developed wet-chemical nanocrystal techniques. Specifically, we interpret the existing literature to advocate that the surface states of this material dominate its observed electrical properties. In an effort to better understand the most prevalent surface, the (100) face, we developed a synthesis that nucleates small (< 20 nm) pyrite nanoparticles and then changes chemical conditions to grow all other faces besides {100} to extinction, creating 37 nm nanocubes. The optical properties of these nanocubes are measured and the phenomenon of resonance light scattering (RLS) is observed. This phenomenon, along with the poor colloidal dispersibility of these nanocubes is then used to promote the idea that an unusual dynamic electronic phenomenon exists on these surfaces. This phenomenon is found to be passivated by introducing charged ligands to the surfaces of these particles. Additionally, after this surface treatment, two very sharp absorption features are observed at 0.73 and 0.88 eV. In connection with recent theoretical work, these transitions are taken as evidence that the (100) surface of pyrite is spin-polarized with each absorption peak being the signal of band edge absorption across a spin-selected direct band gap. A theoretical framework is proposed as a plausible explanation of the observed behavior. To wit, highly localized and energetically disordered Fe d-orbital states fill in the band gap of the (100) pyrite surface that is not perfectly terminated (or nearly so). Frustration between energetic disorder and Coulomb repulsion then results in the formation of metastable states that obscure the observation of these surface transitions and cause the dynamical behavior observed. It is further reasoned that one of these transitions, the one at 0.88 eV, has been observed before in cryogenic absorption and photoconductivity studies, and argued that a plausible reinterpretation of the data from these studies is possible. This reinterpretation can be rationalized within the context of the physical model posited here whereby cryogenic temperatures increase the importance of Coulombic interactions, which results in a decrease in the metastable DOS at the Fermi level and an electronic arrangement closer to that predicted theoretically, despite existing disorder. Finally, it is argued that the frustrated movement of electrons in metastable states can qualitatively explain the apparent conundrum in which surface sensitive probes are unable to measure the effect of isolated defects, despite the highly localized nature of the pyrite (100) surface. Given the range of phenomena this model explains, it may constitute a significant advance in our understanding of the electronic properties of pyrite. Additionally, given that electrochemical conversion of pyrite is a four electron process resulting in a high theoretical discharge capacity of 894 mAh g-1, we have synthesized micron-sized pyrite nanocubes for use in lithium-ion battery research. Previously the use of pyrite in such batteries has only been possible in non-rechargeable architectures. However, work described here shows that a solid state electrolyte can be used to contain the dissolution of these micron sized particles, allowing for battery cycling. This synthesis, especially the effect of pH on morphology, is described within th

  19. BAIAP2 exhibits association to childhood ADHD especially predominantly inattentive subtype in Chinese Han subjects

    PubMed Central

    2013-01-01

    Background Attention-deficit/hyperactivity disorder (ADHD) is a common chronic neurodevelopmental disorder with a high heritability. Much evidence of hemisphere asymmetry has been found for ADHD probands from behavioral level, electrophysiological level and brain morphology. One previous research has reported possible association between BAIAP2, which is asymmetrically expressed in the two cerebral hemispheres, with ADHD in European population. The present study aimed to investigate the association between BAIAP2 and ADHD in Chinese Han subjects. Methods A total of 1,397 ADHD trios comprised of one ADHD proband and their parents were included for family-based association tests. Independent 569 ADHD cases and 957 normal controls were included for case-control studies. Diagnosis was performed according to the DSM-IV criteria. Nine single nucleotide polymorphisms (SNPs) of BAIAP2 were chosen and performed genotyping for both family-based and case-control association studies. Results Transmission disequilibrium tests (TDTs) for family-based association studies showed significant association between the CA haplotype comprised by rs3934492 and rs9901648 with predominantly inattentive type (ADHD-I). For case-control study, chi-square tests provided evidence for the contribution of SNP rs4969239, rs3934492 and rs4969385 to ADHD and its two clinical subtypes, ADHD-I and ADHD-C. However, only the associations for ADHD and ADHD-I retained significant after corrections for multiplicity or logistic regression analyses adjusting the potential confounding effect of gender and age. Conclusions These above results indicated the possible involvement of BAIAP2 in the etiology of ADHD, especially ADHD-I. PMID:24377651

  20. Marked elevation of adrenal steroids, especially androgens, in saliva of prepubertal autistic children.

    PubMed

    Majewska, Maria Dorota; Hill, Martin; Urbanowicz, Ewa; Rok-Bujko, Paulina; Bie?kowski, Przemys?aw; Namys?owska, Irena; Mierzejewski, Pawe?

    2014-06-01

    Autism is diagnosed on the basis of behavioral manifestations, but its biomarkers are not well defined. A strong gender bias typifying autism (it is 4-5 times more prevalent in males) suggests involvement of steroid hormones in autism pathobiology. In order to evaluate the potential roles of such hormones in autism, we compared the salivary levels of 22 steroids in prepubertal autistic male and female children from two age groups (3-4 and 7-9 years old) with those in healthy controls. The steroids were analyzed using gas chromatography-mass spectrometry and radioimmunoassay. Statistical analysis (ANOVA) revealed that autistic children had significantly higher salivary concentrations of many steroid hormones (both C21 and C19) than control children. These anomalies were more prominent in older autistic children and in boys. The levels of androgens (androstenediol, dehydroepiandrosterone, androsterone and their polar conjugates) were especially increased, indicative of precocious adrenarche and predictive of early puberty. The concentrations of the steroid precursor, pregnenolone, and of several pregnanolones were also higher in autistic than in healthy children, but cortisol levels were not different. Some steroids, whose levels are raised in autism (allopregnanolone, androsterone, pregnenolone, dehydroepiandrosterone and their sulfate conjugates) are neuroactive and modulate GABA, glutamate, and opioid neurotransmission, affecting brain development and functioning. These steroids may contribute to autism pathobiology and symptoms such as elevated anxiety, sleep disturbances, sensory deficits, and stereotypies among others. We suggest that salivary levels of selected steroids may serve as biomarkers of autism pathology useful for monitoring the progress of therapy. PMID:24043498

  1. Effect of different agronomic practises on greenhouse gas emissions, especially N2O and nutrient cycling

    NASA Astrophysics Data System (ADS)

    Koal, Philipp; Schilling, Rolf; Gerl, Georg; Pritsch, Karin; Munch, Jean Charles

    2014-05-01

    In order to achieve a reduction of greenhouse gas emissions, management practises need to be adapted by implementing sustainable land use. At first, reliable field data are required to assess the effect of different farming practises on greenhouse gas budgets. The conducted field experiment covers and compares two main aspects of agricultural management, namely an organic farming system and an integrated farming system, implementing additionally the effects of diverse tillage systems and fertilisation practises. Furthermore, the analysis of the alterable biological, physical and chemical soil properties enables a link between the impact of different management systems on greenhouse gas emissions and the monitored cycle of matter, especially the nitrogen cycle. Measurements were carried out on long-term field trials at the Research Farm Scheyern located in a Tertiary hilly landscape approximately 40 km north of Munich (South Germany). The long-term field trials of the organic and integrated farming system were started in 1992. Since then, parcels in a field (each around 0,2-0,4 ha) with a particular interior plot set-up have been conducted. So the 20 years impacts of different tillage and fertilisation practises on soil properties including trace gases were examined. Fluxes of CH4, N2O and CO2 are monitored since 2007 for the integrated farming system trial and since 2012 for the organic farming system trial using an automated system which consists of chambers (per point: 4 chambers, each covering 0,4 m2 area) with a motor-driven lid, an automated gas sampling unit, an on-line gas chromatographic analysis system, and a control and data logging unit (Flessa et al. 2002). Each chamber is sampled 3-4 times in 24 hours. The main outcomes are the analysis of temporal and spatial dynamics of greenhouse gas fluxes as influenced by management practice events (fertilisation and tillage) and weather effects (drying-rewetting, freezing-thawing, intense rainfall and dry periods) in both established systems and the creation of an impact study comparing the minimum tillage system with the conventional tillage system. Physical, chemical and biological soil properties (i.a. texture, mineral nitrogen and soil organic carbon) were monitored to aggregate the parameters and processes influencing the greenhouse gas fluxes. Moreover, to understand processes leading the greenhouse gas emissions, additional experiments under laboratory conditions (e.g. soil potential for trace gas formation) are included. Furthermore, with the comparison of the similar long-term field experiments (organic vs. integrated) more relevant data are ascertained to assess and calculate the global warming potential of different management and tillage systems.

  2. Hay una nueva ley1 en Tennessee sobre el uso de detencin y aislamiento en escuelas pblicas, la cual tomo

    E-print Network

    Cui, Yan

    hijo(a) tiene problemas con su conducta, el equipo de IEP debe de escribir un plan individualizado de apoyo a conducta (BIP), basado en una evaluaci贸n de conducta funcional (FBA). Restricci贸n o reclusi贸n el uso de Restricci贸n y Reclusi贸n en la Educaci贸n Especial y Apoyos Positivos de Conducta (http://www

  3. Sediment analysis does not provide a good measure of heavy metal bioavailability to Cerastoderma glaucum (Mollusca: Bivalvia) in confined coastal ecosystems

    SciTech Connect

    Arjonilla, M.; Gomez-Parra, A. (Instituto de Ciencias Marinas de Andalucia, Puerto Real Cadiz (Spain)); Forja, J.M. (Facultad de Ciencias del Mar, Puerto Real Cadiz (Spain))

    1994-06-01

    Sediments are considered a sink for metals entering the marine environment, especially in coastal areas. Once in the sediment layer, metals are distributed amongst all different phases of the sediment, governed by physicochemical conditions. One fraction is immobilized due to its incorporation into weakly reactive phases of the sediment; Another fraction may remain weakly bound to organic or mineral phases as sorbed, precipitated, or coprecipitated and complexed forms and can be assimilated by detritivorous and suspension-feeding benthic organisms. Many selective procedures have been suggested for metal extraction from sediments in order to estimate concentrations of fractions which are directly or indirectly available to the biota. The absence of a chemical treatment adequate for accurate quantification of metal bioavailability is well-known. Nevertheless, a good correlation between metal content in some organisms and in the sediment after a specific extraction treatment has sometimes been found so sediments are frequently used as indicators in pollution studies. In this paper, concentrations of heavy metals (Fe, Mn, Cu, Ph and Cd) in the cockle Cerastoderma glaucum, and in sediments at the same sampling locations are compared. C. glaucum is a suspension and deposit feeder, inhabiting a wide range of salinities. The study sampled 8 saltponds in the south of Cadiz Bay, located along a gradient of contamination produced by urban and industrial sewage effluents. The study sought to identify areas with different relative risk from metal pollution, in terms of biological effects and effects on water quality due to natural resuspension of sediments or to human relocation of sediments. C. glaucum was selected because of its wide distribution in the Bay, and also because it has no commercial value. This second fact means that its distribution and growth is not directly affected by man. 19 refs., 4 figs., 1 tab.

  4. Delayed and asynchronous ganglionic maturation during cephalopod neurogenesis as evidenced by Sof-elav1 expression in embryos of Sepia officinalis (Mollusca, Cephalopoda).

    PubMed

    Buresi, Auxane; Canali, Ester; Bonnaud, Laure; Baratte, S閎astien

    2013-05-01

    Among the Lophotrochozoa, centralization of the nervous system reaches an exceptional level of complexity in cephalopods, where the typical molluscan ganglia become highly developed and fuse into hierarchized lobes. It is known that ganglionic primordia initially emerge early and simultaneously during cephalopod embryogenesis but no data exist on the process of neuron differentiation in this group. We searched for members of the elav/hu family in the cuttlefish Sepia officinalis, since they are one of the first genetic markers of postmitotic neural cells. Two paralogs were identified and the expression of the most neural-specific gene, Sof-elav1, was characterized during embryogenesis. Sof-elav1 is expressed in all ganglia at one time of development, which provides the first genetic map of neurogenesis in a cephalopod. Our results unexpectedly revealed that Sof-elav1 expression is not similar and not coordinated in all the prospective ganglia. Both palliovisceral ganglia show extensive Sof-elav1 expression soon after emergence, showing that most of their cells differentiate into neurons at an early stage. On the contrary, other ganglia, and especially both cerebral ganglia that contribute to the main parts of the brain learning centers, show a late extensive Sof-elav1 expression. These delayed expressions in ganglia suggest that most ganglionic cells retain their proliferative capacities and postpone differentiation. In other molluscs, where a larval nervous system predates the development of the definitive adult nervous system, cerebral ganglia are among the first to mature. Thus, such a difference may constitute a cue in understanding the peculiar brain evolution in cephalopods. PMID:23047428

  5. Geochemical Redox Indices and microfacies of the Cenomanian-Turonian Agua Nueva/Eagle Ford Fm, Mexico, Evidence for Anoxia Related to OAE2

    NASA Astrophysics Data System (ADS)

    Maurrasse, F. J.; Sanchez-hernandez, Y.; Blanco, A.

    2013-05-01

    Widespread occurrence of black, C-organic-rich sediments within the time of the Cenomanian/Turonian boundary attests to the occurrence of a major global event affecting the carbon cycle coined OAE 2. Intense carbon sequestration in sediments associated with the development of anoxic waters in the deep-ocean and epicontinental seas also led to enhanced export of trace elements as organo-metallic compounds, hence their subsequent enrichment in oxygen-deficient to anoxic sediments. In some areas, stratification of the water column coupled with controlling local factors affected microbial productivity leading to TOC-enriched sediments developed under suboxic/anoxic conditions, in others microbial communities led to high TOC values. We integrate geochemical redox indicators and microfacies characterization to assess oxygenic conditions in the Cenomanian-Turonian C-org-rich deposit of the Agua Nueva Formation and the coeval Eagle Ford Fm/ Boquillas Fm. We studied laminated samples of the Agua Nueva from Xilitla, San Luis Potosi State; San Eugenio (type locality of the Formation), Tamaulipas State; and the Eagle Ford at Quarry Los Temporales, northern Coahuila State). Microfacies at all localities reveal the prevalence of coccoid cyanobacteria, some filamentous morphotypes and degraded shell fragments, as the primary components, regardless of TOC values. Planktonic foraminifera constitute 15 to 20 % of the microfossils reaching highest abundance at Los Temporales, including macro-organisms (crustaceans). Absence of benthic foraminifera, and parallel alignment of all components attest to the absence of bioturbation, thus oxygen-deficient bottom waters. Eagle Ford samples are low in TOC, whereas the Agua Nueva samples are enriched in OM as brown amorphous macerals with bacterial coccospheres in lamination attributed to sustained microbial blooms. TE concentrations (V, Ni, U) and redox indices (V/(V+Ni), Ni/Co, V/Cr and U/Th) from the three localities confirm that these sediments accumulated under oxygen-deprived conditions, as also indicated by samples falling within the suboxic/anoxic region in a V/(V+Ni) vs. Ni/Co plot. Thus, oxygen-deprived conditions in all the areas were not necessary accompanied by high TOC, as is the case of Los Temporales where oxygen levels may have been controlled by water column stratification, analogous to modern-day Black Sea. In areas of high TOC, enhanced primary microbial productivity may have intensified DO demand in the water column causing extension of the oxygen minimum zone not affecting plankton life in the uppermost water column. As a result, like at other OAE2 sites elsewhere, bottoms water became suboxic/anoxic, and in some cases developed sulfidic conditions as indicated by relatively high V/(V+Ni), and pervasive pyrite.

  6. Previously undocumented diversity and abundance of cryptic species: a phylogenetic analysis of Indo-Pacific Arminidae Rafinesque, 1814 (Mollusca: Nudibranchia) with descriptions of 20 new species of Dermatobranchus

    PubMed Central

    Gosliner, Terrence M; Fahey, Shireen J

    2011-01-01

    The phylogenetic relationships amongst the Arminidae were analysed based upon morphological characters of 58 presently described species or nudibranchs, including 35 previously described Arminidae and 20 new species of Dermatobranchus. From the literature review and anatomical examinations, 43 characters were considered for 78 taxa. These characters were polarized using Berthella canariensis as the outgroup taxon and the type species of several other genera identified from recent publications. The resulting phylogeny supports the monophyly of Arminidae, Dermatobranchus, Doridina, and Proctonotidae. The paraphyly of the Arminina is further demonstrated in this study. Two previously described, but poorly known, species of Indo-Pacific Armina are redescribed, Armina magna Baba, 1955 and Armina paucifoliata Baba, 1955. The anatomy and taxonomic status of nine previously described species of Dermatobranchus were examined in this study. The anatomy of Dermatobranchus pustulosus (van Hasselt, 1824) has been overlooked since Bergh (1888) illustrated the radula of van Hasselt's specimen. It is redescribed and its range is extended to several new localities in the western Pacific. Dermatobranchus pulcherrimus Miller & Willan, 1986 is considered here as a new synonym of Dermatobranchus rubidus (Gould, 1852). The following 20 species of Dermatobranchus are new and are described in the present paper: Dermatobranchus albineus sp. nov., Dermatobranchus arminus sp. nov., Dermatobranchus caesitius sp. nov., Dermatobranchus caeruleomaculatus sp. nov., Dermatobranchus cymatilis sp. nov., Dermatobranchus dendonephthyphagus sp. nov., Dermatobranchus diagonalis sp. nov., Dermatobranchus earlei sp. nov., Dermatobranchus fasciatus sp. nov., Dermatobranchus funiculus sp. nov., Dermatobranchus kalyptos sp. nov., Dermatobranchus kokonas sp. nov., Dermatobranchus leoni sp. nov., Dermatobranchus microphallus sp. nov., Dermatobranchus oculus sp. nov., Dermatobranchus phyllodes sp. nov., Dermatobranchus piperoides sp. nov., Dermatobranchus rodmani sp. nov., Dermatobranchus semilunus sp. nov., and Dermatobranchus tuberculatus sp. nov. Eighteen of these new taxa are found in the Indo-Pacific tropics and two are found in temperate South Africa, D. albineus and D. arminus. Unique combinations of morphological characters distinguish these as new species of Dermatobranchus. Several species that are externally similar have radically divergent internal morphology, are members of different clades of Dermatobranchus, and represent cryptic species. Especially important is the radular morphology, which shows remarkable diversity of form, probably related directly to the diversification of feeding of members of this clade on various octocorals. PMID:21527987

  7. REVISI覰 SERRADELA AMARILLA (Ornithopus compressus) Y SERRADELA ROSADA (O. sativus): DOS NUEVAS ESPECIES DE LEGUMINOSAS FORRAJERAS ANUALES PARA LA ZONA MEDITERR罭EA DE CHILE Yellow serradella (Ornithopus compressus) and pink serradella (O. sativus): two new species of annual legumes for the Mediterranean climate zone of Chile

    Microsoft Academic Search

    A B S T R A C T Yellow serradella (Ornithopus compressus L.) and pink serradella (Ornithopus sativus Brot.) are two new annual forage legume species for infertile, acidic, and light texture soils, in dryland areas of the Mediterra- nean zone of Chile. Seven cultivars of yellow serrade- lla and one cultivar of pink serradella, developed by the Center for

  8. CRECIMIENTO Y PRODUCCI覰 DE NUEVAS LEGUMINOSAS FORRAJERAS ANUALES EN LA ZONA MEDITERR罭EA DE CHILE. I. COMPORTAMIENTO DE LAS ESPECIES EN LA PRECORDILLERA ANDINA Growth and production of new annual forage legumes in the Mediterranean zone of Chile. I. Species performance in the Andean foothills

    Microsoft Academic Search

    2005-01-01

    A B S T R A C T This study was carried out for three seasons (2000 to 2002) in the Andean foothills of south central Chile. The climate is Mediterranean perhumid, with 1,200 mm of annual rainfall, the soil is of volcanic origin, called trumao (hashy, mesic typic Haploxerands), deep (> 1 m), with a light texture. The productive

  9. Short communication: Prevalence and risk factors of subclinical mastitis as determined by the California Mastitis Test in water buffaloes (Bubalis bubalis) in Nueva Ecija, Philippines.

    PubMed

    Salvador, R T; Beltran, J M C; Abes, N S; Gutierrez, C A; Mingala, C N

    2012-03-01

    A retrospective analysis using records of lactating Bulgarian Murrah buffaloes subjected to the California Mastitis Test in a herd in Nueva Ecija, Philippines was done to determine the prevalence of subclinical mastitis (SCM) and to identify risk factors that may influence its occurrence and recurrence. Results showed that SCM prevalence was 42.76%, whereas its recurrence was 75.03%. Age and lactation length influenced the occurrence of SCM. In contrast to the conclusions for dairy cows, younger buffalo cows were more susceptible compared with those at least 6 yr old. Dams younger than 3 yr have a 76% probability, whereas those age 3 yr have an 82% probability of having SCM. PMID:22365218

  10. Semi-automatic delimitation of volcanic edifice boundaries: Validation and application to the cinder cones of the Tancitaro-Nueva Italia region (Michoac醤-Guanajuato Volcanic Field, Mexico)

    NASA Astrophysics Data System (ADS)

    Di Traglia, Federico; Morelli, Stefano; Casagli, Nicola; Gardu駉 Monroy, Victor Hugo

    2014-08-01

    The shape and size of monogenetic volcanoes are the result of complex evolutions involving the interaction of eruptive activity, structural setting and degradational processes. Morphological studies of cinder cones aim to evaluate volcanic hazard on the Earth and to decipher the origins of various structures on extraterrestrial planets. Efforts have been dedicated so far to the characterization of the cinder cone morphology in a systematic and comparable manner. However, manual delimitation is time-consuming and influenced by the user subjectivity but, on the other hand, automatic boundary delimitation of volcanic terrains can be affected by irregular topography. In this work, the semi-automatic delimitation of volcanic edifice boundaries proposed by Grosse et al. (2009) for stratovolcanoes was tested for the first time over monogenetic cinder cones. The method, based on the integration of the DEM-derived slope and curvature maps, is applied here to the Tancitaro-Nueva Italia region of the Michoac醤-Guanajuato Volcanic Field (Mexico), where 309 Plio-Quaternary cinder cones are located. The semiautomatic extraction allowed identification of 137 of the 309 cinder cones of the Tancitaro-Nueva Italia region, recognized by means of the manual extraction. This value corresponds to the 44.3% of the total number of cinder cones. Analysis on vent alignments allowed us to identify NE-SW vent alignments and cone elongations, consistent with a NE-SW ?max and a NW-SE ?min. Constructing a vent intensity map, based on computing the number of vents within a radius r centred on each vent of the data set and choosing r = 5 km, four vent intensity maxima were derived: one is positioned in the NW with respect to the Volcano Tancitaro, one in the NE, one to the S and another vent cluster located at the SE boundary of the studied area. The spacing of centroid of each cluster (24 km) can be related to the thickness of the crust (9-10 km) overlying the magma reservoir.

  11. not changed might have its name changed solely owing to a shift in rank. This is especially unfortunate because rank

    E-print Network

    Poff, N. LeRoy

    not changed might have its name changed solely owing to a shift in rank. This is especially unfortunate because rank assignment is subjective and of dubious value (e.g. [2]). Rank-based nomenclature of introducing cumbersome new categories (Parvorder, Cohort, Infraclass, etc.) and/or causing a cascade of rank

  12. CATALOGO ILUSTRADO DE LOS MELOIDAE (COLEOPTERA) DE NICARAGUA Y OTRAS ESPECIES CONTENIDAS EN LAS COLECCIONES DEL MUSEO ENTOMOLOGICO DE LEON

    Microsoft Academic Search

    Por Jean-Michel MAES; Jeffrey P. HUETHER

    Se conocen alrededor de 3000 especies de Meloidae a nivel mundial. Los Meloidae son en general alargados, de elitros blandos. El pronoto es m醩 estrecho que la cabeza y m醩 estrecho que los 閘itros, lo que le da una forma muy caracteristica. Miden de 10 a 40 mm. Algunos Meloidae adultos son plagas menores de cultivos, algunos Epicauta comen las

  13. It is recognized that open ocean properties, especially bio-logical ones, are chronically undersampled. During the last

    E-print Network

    Claustre, Herv

    483 It is recognized that open ocean properties, especially bio- logical ones, are chronically- perature and salinity fields. However, most of the research con- ducted to date using this new technology and salinity using a miniaturized conductivity-temperature-depth (CTD) cell (Fedak 2004; Charrassin et al. 2008

  14. Irrigation with polluted water or wastewater is a widespread reality, especially in low-income countries where it is popularly

    E-print Network

    Scott, Christopher

    Irrigation with polluted water or wastewater is a widespread reality, especially in low are now available to make wastewater use safer and more sustainable without relying on non Partnership (GWP) Advisory Center at IWMI and the GWP Technical Committee. It is based on the book Wastewater

  15. The management of fire-prone forests, especially within the national forests of the west, is one of the

    E-print Network

    California at Berkeley, University of

    is the Healthy Forests Restoration Act (HFRA) of 2003 (Public Law 108-V148). This law has potentially profound as other impacts such as logging and livestock grazing. Uncharacteristic fuel loads contribute to altered of wildlands has intensified problems of managing fire, especially at the wild- land璾rban interface (Dombeck

  16. hal-00878684,version1-30Oct2013 ings, deep reservoirs, confined pillars, etc. An accurate mechanical model is especially

    E-print Network

    Boyer, Edmond

    mechanical model is especially needed in the analysis of damage, aging and degradation phenomena. Following identified by Ortiz (1985), whose model, based on mixture the- ory and damage mechanics, met most Mechanics, introducing phenomenological damage variables. Although damage is inherently a non isotropic

  17. Methyl Eugenol: Its Occurrence, Distribution, and Role in Nature, Especially in Relation to Insect Behavior and Pollination

    PubMed Central

    Tan, Keng Hong; Nishida, Ritsuo

    2012-01-01

    This review discusses the occurrence and distribution (within a plant) of methyl eugenol in different plant species (> 450) from 80 families spanning many plant orders, as well as various roles this chemical plays in nature, especially in the interactions between tephritid fruit flies and plants. PMID:22963669

  18. Fichas de las especies

    Microsoft Academic Search

    Santi Guallar; E. Santana; S. Contreras; H. Verdugo; A. Gall閟

    2009-01-01

    Sittasomus griseicapillus, Xiphorhynchus flavigaster, Myiopagis viridicata, Mitrephanes phaeocercus, \\u000aEmpidonax difficilis \\/ occidentalis, Myiarchus tuberculifer, Myiarchus cinerascens, Myiarchus nuttingi, Myiarchus tyrannulus, Pitangus sulphuratus, Myiozetetes similis, Myiodynastes luteiventris, Pachyramphus aglaiae, Vireo brevipennis, Vireo bellii, Vireo nelsoni, Vireo hypochryseus, \\u000aVireo gilvus, Vireo flavoviridis, Thryothorus sinaloa, Thryothorus felix, Troglodytes brunneicollis, Troglodytes aedon, Henicorhina leucophrys, Polioptila caerulea, Myadestes occidentalis, Catharus aurantiirostris, Catharus occidentalis, Catharus frantzii,

  19. Petrographic Evidence of Microbial Mats in the Upper Cretaceous Fish-Bearing, Organic-Rich Limestone, Agua Nueva Formation, Central Mexico

    NASA Astrophysics Data System (ADS)

    Blanco, A.; Maurrasse, F. J.; Hern醤dez-羦ila, J.; 羘geles-Trigueros, S. A.; Garc韆-Cabrera, M. E.

    2013-05-01

    We document petrographic evidence of microbial mats in the Upper Cretaceous Agua Nueva Formation in the area of Xilitla (San Luis Potos, Central Mexico), located in the southern part of the Tampico-Misantla basin. The sequence consists predominantly of alternating decimeter-thick beds of fossiliferous dark laminated limestone (C-org > 1.0wt%), and light gray, bioturbated limestone (C-org < 1.0wt%), with occasional brown shale and green bentonite layers. Well-preserved fossil-fish assemblages occur in the laminated dark limestone beds, which include shark teeth (cf. Ptychodus), scales of teleosteans (Ichthyodectiformes), as well as skeletal remains of holosteans (Nursallia. sp), and teleosteans (cf. Rhynchodercetis, Tselfatia, and unidentified Enchodontids). Thin section and SEM analyses of the laminated, dark limestones, reveal a micritic matrix consisting of dark and light sub-parallel wavy laminae, continuous and discontinuous folded laminae with shreds of organic matter, filaments, oncoids, and interlocking structures. The structures are identical to those previously described for the Cenomanian-Turonian Indidura Fm at Parras de la Fuente (Coahuila state) demonstrated to be of microbial origin (Duque-Botero and Maurrasse, 2005; 2008). These structures are also analogous to microbial mats in present environments, and Devonian deposits (Kremer, 2006). In addition, the laminae at Xilitla include filamentous bacterial structures, as thin and segmented red elements. In some thin sections, filaments appear to be embedded within the crinkly laminae and shreds showing the same pattern of folding, suggestive of biomorphic elements that represent the main producers of the organic matter associated with the laminae. Thus, exceptional bacterial activity characterizes sedimentation during the accumulation of the Agua Nueva Formation. Oxygen-deficient conditions related to the microbial mats were an important element in the mass mortality and preservation of the fish assemblages. Absence of bioturbation, pervasive framboidal pyrite, and the high concentration of organic matter (TOC ranges from 1.2% to 8wt%) in the dark limestones are consistent with persistent recurring dysoxic/anoxic conditions, and the light-gray bioturbated limestones represent relatively well-oxygenated episodes. Planktonic foraminifera (Rotalipora cushmani) and Inoceramu labiatus indicate a time interval from the latest Cenomanian through the earliest Turonian, thus this long interval of severe oxygen deficiency is coeval with Oceanic Anoxic Event 2 (OAE-2). [Duque-Botero and Maurrasse. 2005. Jour. Iberian Geology (31), 85-98; 2008. Cret. Res., 29, 957-964; Kremer. 2006. Acta Palaeontologica Polonica (51, 1), 143-154

  20. FRESHWATER SNAILS (MOLLUSCA: GASTROPODA) OF NORTH AMERICA

    EPA Science Inventory

    Freshwater gastropod mollusks are represented in North America (north of Mexico) by 15 families, 78 genera and, as treated in this manual, 499 species. They are grouped into two large subclasses, the gill-breathing, operculated Prosobranchia and the lung-breathing, non-operculate...

  1. A Synoptical Classification of the Bivalvia (Mollusca)

    E-print Network

    Carter, Joseph G.; Altaba, Cristian R.; Anderson, Laurie C.; Araujo, Rafael; Biakov, Alexander S.; Bogan, Arthur E.; Campbell, David C.; Campbell, Matthew; Chen, Jin-hua; Cope, John C. W.; Delvene, Graciela; Dijkstra, Henk H.; Fang, Zong-jie; Gardner, Ronald N.; Gavrilova, Vera A.; Goncharova, Irina A.; Harries, Peter J.; Hartman, Joseph H.; Hautmann, Michael; Hoeh, Walter R.; Hylleberg, Jorgen; Jiang, Bao-yu; Johnston, Paul; Kirkendale, Lisa; Kleemann, Karl; Koppka, Jens; K?í , Ji?í Machado, Deusana; Malchus, Nikolaus; Má rquez-Aliaga, Ana; Masse, Jean-Pierre; McRoberts, Christopher A.; Middelfart, Peter U.; Mitchell, Simon; Nevesskaja, Lidiya A.; Ö zer, Sacit; Pojeta, John Jr.; Polubotko, Inga V.; Pons, Jose Maria; Popov, Sergey; Sá nchez, Teresa; Sartori, André F.; Scott, Robert W.; Sey, Irina I.; Signorelli, Javier H.; Silantiev, Vladimir V.; Skelton, Peter W.; Steuber, Thomas; Waterhouse, J. Bruce; Wingard, G. Lynn; Yancey, Thomas

    2011-10-27

    , Peter J. Harries, Joseph H. Hartman, Michael Hautmann, Walter R. Hoeh, Jorgen Hylleberg, Jiang Bao-yu, Paul Johnston, Lisa Kirkendale, Karl Kleemann, Jens Koppka, Ji? K?頌, Deusana Machado, Nikolaus Malchus, Ana M醨quez-Aliaga, Jean-Pierre Masse... Machado, Nikolaus Malchus, Ana M醨quez-Aliaga, Jean-Pierre Masse, Christopher A. McRoberts, Peter U. Middelfart, Simon Mitchell, Lidiya A. Nevesskaja, Sacit 謟er, John Pojeta, Jr., Inga V. Polubotko, Jose Maria Pons, Sergey Popov, Teresa S醤chez, Andr F...

  2. Molecular phylogenetics of Caenogastropoda (Gastropoda: Mollusca).

    PubMed

    Colgan, D J; Ponder, W F; Beacham, E; Macaranas, J

    2007-03-01

    Caenogastropoda is the dominant group of marine gastropods in terms of species numbers, diversity of habit and habitat and ecological importance. This paper reports the first comprehensive multi-gene phylogenetic study of the group. Data were collected from up to six genes comprising parts of 18S rRNA, 28S rRNA (five segments), 12S rRNA, cytochrome c oxidase subunit I, histone H3 and elongation factor 1alpha. The alignment has a combined length of 3995 base positions for 36 taxa, comprising 29 Caenogastropoda representing all of its major lineages and seven outgroups. Maximum parsimony, maximum likelihood and Bayesian analyses were conducted. The results generally support monophyly of Caenogastropoda and Hypsogastropoda (Caenogastropoda excepting Architaenioglossa, Cerithioidea and Campanilioidea). Within Hypsogastropoda, maximum likelihood and Bayesian analyses identified a near basal clade of nine or 10 families lacking an anterior inhalant siphon, and Cerithiopsidae s.l. (representing Triphoroidea), where the siphon is probably derived independently from other Hypsogastropoda. The asiphonate family Eatoniellidae was usually included in the clade but was removed in one Bayesian analysis. Of the two other studied families lacking a siphon, the limpet-shaped Calyptraeidae was associated with this group in some analyses, but the tent-shaped Xenophoridae was generally associated with the siphonate Strombidae. The other studied hypsogastropods with an anterior inhalant siphon include nine families, six of which are Neogastropoda, the only traditional caenogastropod group above the superfamily-level with strong morphological support. The hypotheses that Neogastropoda are monophyletic and that the group occupies a derived position within Hypsogastropoda are both contradicted, but weakly, by the molecular analyses. Despite the addition of large amounts of new molecular data, many caenogastropod lineages remain poorly resolved or unresolved in the present analyses, possibly due to a rapid radiation of the Hypsogastropoda following the Permian-Triassic extinction during the early Mesozoic. PMID:17127080

  3. Notes on New Zealand chitons (Mollusca, Amphineura)

    Microsoft Academic Search

    A. G. Beu

    1967-01-01

    A synopsis of the classification of the New Zealand Polyplacophora is presented. The name Lepidochitonidae is replaced by the earlier Callochitonidae, Plaxi?phoridae by Mopaliidae, Aulacochitonidae by Schizochitonidae, and Cryptocon?chidae by Acanthochitonidae.Vaferichiton Iredale and Hull is treated as a subgenus of Aerilamma Hull. Lorica H. and A. Adams is used instead of its junior synonym Aulacochiton Shuttleworth. Lorica haurakiensis Mestayer is

  4. Hyperhomocysteinemia is one of the risk factors associated with cerebrovascular stiffness in hypertensive patients, especially elderly males

    PubMed Central

    Okura, Takafumi; Miyoshi, Ken-ichi; Irita, Jun; Enomoto, Daijiro; Nagao, Tomoaki; Kukida, Masayoshi; Tanino, Akiko; Kudo, Kayo; Pei, Zouwei; Higaki, Jitsuo

    2014-01-01

    Hyperhomocystemia has been reported to be associated with cardiovascular disease, especially stroke. The resistive index (RI) estimated by carotid ultrasound is an established variable for estimating the risk of cerebral infarction. The aim of this study was to evaluate the relationship between homocysteine concentration and carotid RI, a marker of cerebral vascular resistance in essential hypertensive patients. We measured serum total homocysteine and carotid RI in 261 patients. Multiple linear regression analysis was used to determine the association of homocysteine with carotid RI and intima media thickness (IMT). Age, sex, BMI, systolic blood pressure (SBP), homocysteine, total cholesterol, high density lipoprotein-cholesterol (HDL-C), uric acid, CRP, HbA1c, estimated glomerular filtration rate, and use of antihypertensive agents were included as independent variables. Age, sex, use of antihypertensive agents, HDL-C and homocysteine levels were shown to be significant predictors of carotid RI, but not IMT. Multiple regression analysis in men older than 65 years showed homocysteine and SBP were associated significantly with carotid RI. In elderly male patients, homocysteine was the strongest predictor of carotid RI (B = 0.0068, CI = 0.00170.0120, P = 0.011) in the multivariate model. In conclusion, hyperhomocysteinemia is associated with carotid RI, a surrogate marker of cerebral vascular resistance, especially in elderly men. PMID:25012721

  5. Cyanobacteria/Foraminifera Association from Anoxic/Dysoxic Beds of the Agua Nueva Formation (Upper Cretaceous - Cenomanian/Turonian) at Xilitla, San Luis Potosi, Central Mexico

    NASA Astrophysics Data System (ADS)

    Blanco-Pi耋n, A.; Maurrasse, F. J.; Rojas-Le髇, A.; Duque-Botero, F.

    2008-05-01

    The Agua Nueva Formation in the vicinity of Xilitla, State of San Luis Potos, Central Mexico, consists of interbedded brown shale (Grayish orange 10YR 7/4 to Moderate yellowish brown 10YR 5/4) and dark-gray fossiliferous limestone (Bluish gray 5B 6/1 to Dark bluish gray 5B 4/1), varying between 10 and 20 cm in thickness. The sequence also includes 2 to 4 cm- thick intermittent bentonite layers (Moderate greenish yellow 10Y 7/4, to dark greenish yellow 10Y 6/6 and Light olive 10Y 5/4). At the field scale, shaly intervals show no apparent internal structures, whereas most limestone beds show primary lamination at the millimeter scale (1-2 mm), and intermittent layers of black chert of about 5 cm thick. Pyrite is present as disseminated crystals and as 2 cm-thick layers. Bioturbation or macrobenthic organisms other than inoceramids do not occur in the Agua Nueva Formation at Xilitla. Unusual macrofossils are present only in limestone strata, and consist of well- preserved diverse genera of fishes such as sharks, Ptychodus sp. and teleosteans, Rhynchodercetis sp., Tselfatia sp., Goulmimichthys sp., and scales of Ichtyodectiformes, as well as ammonites and inoceramids (Blanco et al., 2006). The presence of Inoceramus (Mytyloides) labiatus (Maldonado-Koederll, 1956) indicates an Early Turonian age for the sequence. Total carbonate content (CaCO3 = TIC) varies between 62 and 94% in the Limestone beds, which yield Total Organic Carbon (TOC) from 0.4% to 2.5%; the shale intervals contain TIC values consistently lower than 33% and TOC lower than 0.8% Microscopically the limestone beds vary from mudstone to packstone composed essentially of coccoid cyanobacteria similar to coeval deposits in northeastern Mexico, Coahuila State, at Parras de La Fuente (Duque- Botero 2006). Similarly, the microspheroids are spherical to sub-spherical, and occur as isolated elements or aggregates forming series of chains of parallel-packed light lamina 1-2 mm thick. Filamentous cyanobacteria (> 1 mm in length) are also present oriented parallel to stratification. In addition to filamentous and coccoid cyanobacteria, the limestone beds contain rare benthic foraminifera, common planktic foraminifera, heterohelicids, Rotalipora spp., Rotalipora cf cushmani, Whiteinella spp, W. praehelvetica, which indicate a time interval from the latest Cenomanian to the earliest Turonian. Lithological, paleontological and microfacies data thus indicate that the sediments accumulated in open-marine to semi-restricted platform environments, under low-energy conditions. Primary lamination, pyrite and excellent degree of preservation of fishes, suggest that low oxygen concentration lead to the formation of anoxic/dysoxic conditions during the accumulation of these exceptional deposits, which are coeval with the worldwide development of OAE-2. Planktonic foraminifera and fishes indicate oxygenated conditions in the photic zone, but dysoxic/anoxic conditions near the bottom, which is consistent with the presence of inoceramids and the absence of bioturbation in the sediment.

  6. New BAC probe set to narrow down chromosomal breakpoints in small and large derivative chromosomes, especially suited for mosaic conditions.

    PubMed

    Hamid, Ahmed B; Fan, Xiaobo; Kosyakova, Nadezda; Radhakrishnan, Gopakumar; Liehr, Thomas; Karamysheva, Tatyana

    2015-01-01

    Fluorescence in situ hybridization (FISH) and/or array-comparative genomic hybridization (aCGH) performed after initial banding cytogenetics is still the gold standard for detection of chromosomal rearrangements. Although aCGH provides a higher resolution, FISH has two main advantages over the array-based approaches: (1) it can be applied to characterize balanced as well as unbalanced rearrangements, whereas aCGH is restricted to unbalanced ones, and (2) chromosomal aberrations present in low level or complex mosaics can be characterized by FISH without any problems, while aCGH requires presence of over 50 % of aberrant cells in the sample for detection. Recently, a new FISH-based probe set was presented: the so-called pericentric-ladder-FISH (PCL-FISH) that enables characterization of chromosomal breakpoints especially in mosaic small supernumerary marker chromosomes (sSMC). It can also be applied on large inborn or acquired derivative chromosomes. The main feature of this set is that the probes are applied in a chromosome-specific manner and they align along the chromosome in average intervals of ten megabasepairs. Hence PCL-FISH provides denser coverage and a more precise anchorage on the human DNA-sequence than most other FISH-banding approaches. PMID:25239752

  7. Glitter-Like Iridescence within the Bacteroidetes Especially Cellulophaga spp.: Optical Properties and Correlation with Gliding Motility

    PubMed Central

    Kientz, Betty; Ducret, Adrien; Luke, Stephen; Vukusic, Peter; Mignot, T鈓; Rosenfeld, Eric

    2012-01-01

    Iridescence results from structures that generate color. Iridescence of bacterial colonies has recently been described and illustrated. The glitter-like iridescence class, created especially for a few strains of Cellulophaga lytica, exhibits an intense iridescence under direct illumination. Such color appearance effects were previously associated with other bacteria from the Bacteroidetes phylum, but without clear elucidation and illustration. To this end, we compared various bacterial strains to which the iridescent trait was attributed. All Cellulophaga species and additional Bacteroidetes strains from marine and terrestrial environments were investigated. A selection of bacteria, mostly marine in origin, were found to be iridescent. Although a common pattern of reflected wavelengths was recorded for the species investigated, optical spectroscopy and physical measurements revealed a range of different glitter-like iridescence intensity and color profiles. Importantly, gliding motility was found to be a common feature of all iridescent colonies. Dynamic analyses of 揼litter formation at the edges of C. lytica colonies showed that iridescence was correlated with layer superposition. Both gliding motility, and unknown cell-to-cell communication processes, may be required for the establishment, in time and space, of the necessary periodic structures responsible for the iridescent appearance of Bacteroidetes. PMID:23300811

  8. Roles of unsaturated fatty acids (especially omega-3 fatty acids) in the brain at various ages and during ageing.

    PubMed

    Bourre, J M

    2004-01-01

    Among various organs, in the brain, the fatty acids most extensively studied are omega-3 fatty acids. Alpha-linolenic acid (18:3omega3) deficiency alters the structure and function of membranes and induces minor cerebral dysfunctions, as demonstrated in animal models and subsequently in human infants. Even though the brain is materially an organ like any other, that is to say elaborated from substances present in the diet (sometimes exclusively), for long it was not accepted that food can have an influence on brain structure, and thus on its function. Lipids, and especially omega-3 fatty acids, provided the first coherent experimental demonstration of the effect of diet (nutrients) on the structure and function of the brain. In fact the brain, after adipose tissue, is the organ richest in lipids, whose only role is to participate in membrane structure. First it was shown that the differentiation and functioning of cultured brain cells requires not only alpha-linolenic acid (the major component of the omega-3, omega3 family), but also the very long omega-3 and omega-6 carbon chains (1). It was then demonstrated that alpha-linolenic acid deficiency alters the course of brain development, perturbs the composition and physicochemical properties of brain cell membranes, neurones, oligodendrocytes, and astrocytes (2). This leads to physicochemical modifications, induces biochemical and physiological perturbations, and results in neurosensory and behavioural upset (3). Consequently, the nature of polyunsaturated fatty acids (in particular omega-3) present in formula milks for infants (premature and term) conditions the visual and cerebral abilities, including intellectual. Moreover, dietary omega-3 fatty acids are certainly involved in the prevention of some aspects of cardiovascular disease (including at the level of cerebral vascularization), and in some neuropsychiatric disorders, particularly depression, as well as in dementia, notably Alzheimer's disease. Recent results have shown that dietary alpha-linolenic acid deficiency induces more marked abnormalities in certain cerebral structures than in others, as the frontal cortex and pituitary gland are more severely affected. These selective lesions are accompanied by behavioural disorders more particularly affecting certain tests (habituation, adaptation to new situations). Biochemical and behavioural abnormalities are partially reversed by a dietary phospholipid supplement, especially omega-3-rich egg yolk extracts or pig brain. A dose-effect study showed that animal phospholipids are more effective than plant phospholipids to reverse the consequences of alpha-linolenic acid deficiency, partly because they provide very long preformed chains. Alpha-linolenic acid deficiency decreases the perception of pleasure, by slightly altering the efficacy of sensory organs and by affecting certain cerebral structures. Age-related impairment of hearing, vision and smell is due to both decreased efficacy of the parts of the brain concerned and disorders of sensory receptors, particularly of the inner ear or retina. For example, a given level of perception of a sweet taste requires a larger quantity of sugar in subjects with alpha-linolenic acid deficiency. In view of occidental eating habits, as omega-6 fatty acid deficiency has never been observed, its impact on the brain has not been studied. In contrast, omega-9 fatty acid deficiency, specifically oleic acid deficiency, induces a reduction of this fatty acid in many tissues, except the brain (but the sciatic nerve is affected). This fatty acid is therefore not synthesized in sufficient quantities, at least during pregnancy-lactation, implying a need for dietary intake. It must be remembered that organization of the neurons is almost complete several weeks before birth, and that these neurons remain for the subject's life time. Consequently, any disturbance of these neurons, an alteration of their connections, and impaired turnover of their constituents at any stage of life, will tend to accelerate ageing. The enzymatic activities of s

  9. Isolation of a potent antibiotic producer bacterium, especially against MRSA, from northern region of the Persian Gulf

    PubMed Central

    Darabpour, Esmaeil; Ardakani, Mohammad Roayaei; Motamedi, Hossein; Ronagh, Mohammad Taghi

    2012-01-01

    Nowadays, emergence and prevalence of MRSA (Methicillin Resistant Staphylococcus aureus) strain have become a great global concern in 21st century, so, it is necessary to discover new antibiotics against this pathogen. The aim of this study was isolation and evaluation marine bacteria from the Persian Gulf in order to finding antibiotic compounds against some pathogenic bacteria. For this purpose, water and sediment samples were collected from the Persian Gulf during March to October 2009. The antibacterial activity of the isolated bacteria was assessed using disc diffusion method. The Growth Curve Interference (GCI) parameter against MRSA was determined for the high potential antibiotic producing strain. The most important factors affecting fermentation conditions in antibiotic production were also optimized. Definite identification of intended isolate was confirmed by 16S rRNA sequencing. Altogether, 51 bacterial colony was isolated and among them only 3 bacterium showed antibacterial activity. Pseudoalteromonaspiscicida PG-01 isolated from a sediment sample was chosen as the best antibiotic producing strain. This strain was effective against all tested Gram-positive bacteria, had good anti-MRSA activity and also GCI value against MRSA was two times lower than MIC value. Among the optimized fermentation parameters, carbon and nitrogen sources play major role in efficacy of optimized antibiotic production. Ultrastructural study on the effect of intended antibiotic compounds on MRSA using TEM revealed that the target site for this compound is cell wall. Considering the antibacterial effect of PG-01 strain especially against MRSA, intended antibiotic compounds can gives hope for treatment of diseases caused by multi-drug resistant bacteria. PMID:22642595

  10. Effect of cotton bollworm (Helicoverpa armigera H黚ner) caused injury on maize grain content, especially regarding to the protein alteration.

    PubMed

    Keszthelyi, S; P醠-F醡, F; Kerepesi, I

    2011-03-01

    The cotton bollworm (Helicoverpa armigera H黚ner), which migrated in the Carpathian-basin from Mediterraneum in the last decades, is becoming an increasingly serious problem for maize producers in Hungary. In several regions the damage it causes has reached the threshold of economic loss, especially in the case of the sweet maize cultivation. The aim of the research was to determine the changing of ears weights and in-kernel accumulation and alteration in grain as a function of cotton bollworm mastication.Our investigation confirmed that there is an in-kernel and protein pattern change of maize grain by cotton bollworm. Our results proved the significant damaging of each part of ears by cotton bollworm masticating (the average weight loss of ears: 13.99%; the average weight loss of grains: 14.03%; the average weight loss of cobs: 13.74%), with the exception of the increasing of the grain-cob ratio. Our examinations did not prove the water loss - that is the "forced maturing" - caused by the damage. Decreasing of raw fat (control: 2.8%; part-damaged: 2.6%; damaged: 2.4%) and starch content (control: 53.1%; part-damaged: 46.6%; damaged: 44.7%) were registered as a function of injury. In contrast, the raw protein content was increased (control: 4.7%; part-damaged: 5.3%; damaged: 7.4%) by maize ear masticating. The most conspicuous effect on protein composition changing was proved by comparison of damaged grain samples by SDS PAGE. Increased amounts of 114, 50, 46 and 35 kDa molecular mass proteins were detected which explained the more than 50% elevation of raw protein content. The statistical analysis of molecular weights proved the protein realignment as a function of the pest injuries, too. PMID:21388919

  11. Households across All Income Quintiles, Especially the Poorest, Increased Animal Source Food Expenditures Substantially during Recent Peruvian Economic Growth

    PubMed Central

    Humphries, Debbie L.; Behrman, Jere R.; Crookston, Benjamin T.; Dearden, Kirk A.; Schott, Whitney; Penny, Mary E.

    2014-01-01

    Background Relative to plant-based foods, animal source foods (ASFs) are richer in accessible protein, iron, zinc, calcium, vitamin B-12 and other nutrients. Because of their nutritional value, particularly for childhood growth and nutrition, it is important to identify factors influencing ASF consumption, especially for poorer households that generally consume less ASFs. Objective To estimate differential responsiveness of ASF consumption to changes in total household expenditures for households with different expenditures in a middle-income country with substantial recent income increases. Methods The Peruvian Young Lives household panel (n?=?1750) from 2002, 2006 and 2009 was used to characterize patterns of ASF expenditures. Multivariate models with controls for unobserved household fixed effects and common secular trends were used to examine nonlinear relationships between changes in household expenditures and in ASF expenditures. Results Households with lower total expenditures dedicated greater percentages of expenditures to food (58.4% vs.17.9% in 2002 and 24.2% vs. 21.5% in 2009 for lowest and highest quintiles respectively) and lower percentages of food expenditures to ASF (22.8% vs. 33.9% in 2002 and 30.3% vs. 37.6% in 2009 for lowest and highest quintiles respectively). Average percentages of overall expenditures spent on food dropped from 47% to 23.2% between 2002 and 2009. Households in the lowest quintiles of expenditures showed greater increases in ASF expenditures relative to total consumption than households in the highest quintiles. Among ASF components, meat and poultry expenditures increased more than proportionately for households in the lowest quintiles, and eggs and fish expenditures increased less than proportionately for all households. Conclusions Increases in household expenditures were associated with substantial increases in consumption of ASFs for households, particularly households with lower total expenditures. Increases in ASF expenditures for all but the top quintile of households were proportionately greater than increases in total food expenditures, and proportionately less than overall expenditures. PMID:25372596

  12. Isolation of a potent antibiotic producer bacterium, especially against MRSA, from northern region of the Persian Gulf.

    PubMed

    Darabpour, Esmaeil; Roayaei Ardakani, Mohammad; Motamedi, Hossein; Taghi Ronagh, Mohammad

    2012-05-01

    Nowadays, emergence and prevalence of MRSA (Methicillin Resistant Staphylococcus aureus) strain have become a great global concern in 21st century, so, it is necessary to discover new antibiotics against this pathogen. The aim of this study was isolation and evaluation marine bacteria from the Persian Gulf in order to finding antibiotic compounds against some pathogenic bacteria. For this purpose, water and sediment samples were collected from the Persian Gulf during March to October 2009. The antibacterial activity of the isolated bacteria was assessed using disc diffusion method. The Growth Curve Interference (GCI) parameter against MRSA was determined for the high potential antibiotic producing strain. The most important factors affecting fermentation conditions in antibiotic production were also optimized. Definite identification of intended isolate was confirmed by 16S rRNA sequencing. Altogether, 51 bacterial colony was isolated and among them only 3 bacterium showed antibacterial activity. Pseudoalteromonas piscicida PG-01 isolated from a sediment sample was chosen as the best antibiotic producing strain. This strain was effective against all tested Gram-positive bacteria, had good anti-MRSA activity and also GCI value against MRSA was two times lower than MIC value. Among the optimized fermentation parameters, carbon and nitrogen sources play major role in efficacy of optimized antibiotic production. Ultrastructural study on the effect of intended antibiotic compounds on MRSA using TEM revealed that the target site for this compound is cell wall. Considering the antibacterial effect of PG-01 strain especially against MRSA, intended antibiotic compounds can gives hope for treatment of diseases caused by multi-drug resistant bacteria. PMID:22642595

  13. Nueva dramaturgia cubana: Tres entrevistas

    E-print Network

    Espinosa Domí nguez, Carlos

    1981-10-01

    David 1977. Toto me brind, por otra parte, la oportunidad de utilizar y de tratar po閠icamente el lenguaje. El personaje mismo del protagonista ofrec韆 am plias posibilidades en cuanto al aprovechamiento de la poes韆, al punto de que en ocasiones...

  14. StalAge - A new algorithm especially designed for the construction of speleothem age-depth models

    NASA Astrophysics Data System (ADS)

    Scholz, Denis; Hoffmann, Dirk

    2010-05-01

    A standard approach to construct age-depth models for speleothems on the basis of 230Th/U-ages is not available yet. Some studies apply linear interpolation between dated depths; others use least squares polynomial fits. Other authors, in turn, use various kinds of splines or even more sophisticated methods based on the general growth mechanisms of speleothems. A general approach to estimate the uncertainty of stalagmite age models has neither been developed yet. Since the exact determination of the timing and duration of climatic events recorded in speleothem calcite depends on the method used to calculate the age model, a general technique for the calculation of both the age model and its uncertainty is urgently needed. Here we present a new algorithm, especially designed for constructing age-depth models based on speleothem 230Th/U-ages. The algorithm relies on two basic assumptions: (i) the age model must increase monotonically with increasing distance from top of the stalagmite, and (ii) if possible within the associated error bars, the simplest age-depth relationship (i.e., a straight line) is fitted to the age data. Whereas the first assumption simply arises from the absolute constraint of increasing age with increasing distance from top, the second assumption avoids over-interpretation of the age data. The performance of the algorithm was tested using synthetic speleothem age data. For this purpose, a numerical model simulating (i) speleothem growth, (ii) incorporation and temporal evolution of U-series isotopes and (iii) mass spectrometric analysis was developed. This allows simulation of extreme scenarios, such as stalagmite sections including obvious outliers, age inversions and pronounced detrital contamination, and also to test the performance and robustness of the algorithm under these conditions. The developed algorithm has distinct advantages in comparison with the existing methods. Firstly, it is very robust. Outliers and age inversions are automatically detected and taken into account for the calculation of the age model and its uncertainty. The uncertainty in such sections is appropriately enlarged and, thus, probably more realistic than that calculated by other methods. Secondly, the inclusion of the monotonicity criterion provides additional information apart from the 230Th/U-ages and the corresponding errors. This results in smaller errors than those calculated by other methods in sections without age inversions. The algorithm is written in the free statistical software R and will be made available as a free download to the speleothem community.

  15. Urinary Interleukin-8 Is a Biomarker of Stress in Emergency Physicians, Especially with Advancing Age The JOBSTRESS* Randomized Trial

    PubMed Central

    Dutheil, Fr閐閞ic; Trousselard, Marion; Perrier, Christophe; Lac, G閞ard; Chamoux, Alain; Duclos, Martine; Naughton, Geraldine; Mnatzaganian, George; Schmidt, Jeannot

    2013-01-01

    Background Emergency physicians are exposed to greater stress during a 24-hour shift (24 hS) than a 14-hour night shift (14 hS), with an impact lasting several days. Interleukin-8 (IL-8) is postulated to be a chronic stress biomarker. However, no studies have tracked IL-8 over several shifts or used it for monitoring short-term residual stress. The IL-8 response to the shifts may also increase with age. Conveniently, IL-8 can be measured non-intrusively from urine. Methods We conducted a shifts-randomized trial comparing 17 emergency physicians urinary IL-8 levels during a 24 hS, a 14 hS, and a control day (clerical work on return from leave). Mean levels of IL-8 were compared using a Wilcoxon matched-pairs test. Independent associations of key factors including shifts, stress, and age with IL-8 levels were further assessed in a multivariable generalized estimating equations model. Results Mean urinary IL-8 levels almost doubled during and after a 24 hS compared with a 14 hS or a control day. Furthermore, IL-8 levels failed to return to control values at the end of the third day after the shift despite a rest day following the 24 hS. In the multivariable model, engaging in a 24 hS, self-reported stress, and age were independently associated with higher IL-8 levels. A 24 hS significantly increased IL-8 levels by 1.9 ng (p?=?.007). Similarly, for every unit increase in self-reported stress, there was a 0.11 ng increase in IL-8 levels (p?=?.003); and for every one year advance in age of physicians, IL-8 levels also increased by 0.11 ng (p?=?.018). Conclusion The 24 hS generated a prolonged response of the immune system. Urinary IL-8 was a strong biomarker of stress under intensive and prolonged demands, both acutely and over time. Because elevated IL-8 levels are associated with cardiovascular disease and negative psychological consequences, we suggest that emergency physicians limit their exposure to 24 hS, especially with advancing age. PMID:23977105

  16. There is an increasing order in digitized technology. This increasing order requires high qualitative document management system which can be used in secure fashion especially for organization with

    E-print Network

    qualitative document management system which can be used in secure fashion especially for organization which are connected together in a sequential fashion and cannot be separate. Also it ensures reliability

  17. Drug addiction is a common problem in this country, especially for adolescents. The detrimental effects of exposure to addictive drugs during adolescence continue to

    E-print Network

    Minnesota, University of

    Background Drug addiction is a common problem in this country, especially for adolescents. The detrimental effects of exposure to addictive drugs during adolescence continue to affect individuals addiction and dependence requires us to refine measures of emotional states and use these measures

  18. Carbon Sequestration to Mitigate Climate Change Human activities, especially the burning of fossil fuels such as coal, oil, and gas, have caused a substantial increase

    E-print Network

    Carbon Sequestration to Mitigate Climate Change Human activities, especially the burning of fossil-caused CO2 emissions and to remove CO2 from the atmosphere. 2.0 What is carbon sequestration? The term "carbon sequestration" is used to describe both natural and deliberate CARBON,INGIGATONSPERYEAR 1.5 Fossil

  19. Collaborative Research: Barotropic Radiation Experiment (BARX) The question of how energy flows through the oceans, especially how energy is lost from the currents

    E-print Network

    Dushaw, Brian

    flows through the oceans, especially how energy is lost from the currents comprising the general and vorticity. Intellectual Merit. A fundamental process by which ocean currents lose the energy acquired from Variability in the Central North Atlantic Ocean 1. Motivations and Objectives The paths along which energy

  20. Sesso Especial: Novas Tendncias em Modelagem do Sistema Terrestre (New Trends on Land System Modelling) Coordenadores: Gilberto Cmara (INPE) e Giovana Espindola (IPO-GLP/INPE)

    E-print Network

    Sess茫o Especial: Novas Tend锚ncias em Modelagem do Sistema Terrestre (New Trends on Land System m煤ltipla escala, obteremos novas informa莽玫es sobre os processos que comandam as mudan莽as do sistema

  1. The Career Center34 You may be concerned about how to effectively communicate what you have to offer potential employers, especially

    E-print Network

    Kasman, Alex

    are skills related to a specific job. Laboratory skills and programming skills are examples of jobThe Career Center34 You may be concerned about how to effectively communicate what you have to offer potential employers, especially if you have limited job-related experience. However, you probably

  2. Chrysomelids American diabroticines Hosts and natural enemies. Biology-feasibility for control of pest species (Crisomelidos Diabroticinos americanos Hospederos y enemigos naturales Biologia y factibili manejo especies plagas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The chrysomelids in the Diabroticites include some of the most important pest species of the American continent. The chemical and management techniques used to date to control them are: crop rotation to prevent re-infection of host crops, especially in the species that display an egg diapause; insec...

  3. Variaciones temporales en la composici髇 y abundancia de cuatro especies de Cancer (Decapoda: Brachyura: Cancridae) capturadas con trampas en bah韆 San Vicente, Concepci髇 (Chile central)

    Microsoft Academic Search

    Carlos A. Mu駉z; Luis M. Pardo; Luis A. Henr韖uez; 羖varo T. Palma

    2006-01-01

    This study analyzes the composition and distribution of the main brachyuran decapod crustacean species caught by small-scale fishermen in the coastal area off the Hualp閚 Peninsula (Concepci髇). These patterns were then compared and related to variations in temperature and extraction depth. The catches throughout the year were basically represented by four Cancer species, especially in autumn 2003, when C. porteri

  4. Sesso Especial: Big Data em Observao da Terra: infraestruturas e anlises espao-temporais (Big Earth Observation Databases: infrastructure and spatiotemporal analysis)

    E-print Network

    Sess茫o Especial: Big Data em Observa莽茫o da Terra: infraestruturas e an谩lises espa莽o-temporais (Big of information from big Earth Observation data sets in an open and reproducible way? In response, access, processing and analysis of big Earth Observation data. The presentations will focus

  5. La Convencin sobre el Comercio Internacional de Especies Amenazadas de Fauna y Flora Silvestres (CITES, por sus siglas en ingls) es un acuerdo internacional firmado por

    E-print Network

    La Convenci髇 sobre el Comercio Internacional de Especies Amenazadas de Fauna y Flora Silvestres garantizar que el comercio internacional de animales y plantas no amenace su supervivencia en la naturaleza (CITES, por sus siglas en ingl閟) es un acuerdo internacional firmado por 178 naciones designadas para

  6. La Convencin sobre el Comercio Internacional de Especies Amenazadas de Fauna y Flora Silvestres (CITES, por sus siglas en ingls) es un acuerdo internacional firmado

    E-print Network

    La Convenci髇 sobre el Comercio Internacional de Especies Amenazadas de Fauna y Flora Silvestres garantizar que el comercio internacional de animales y plantas silvestres no amenaza su supervivencia en la (CITES, por sus siglas en ingl閟) es un acuerdo internacional firmado por 176 naciones designadas para

  7. Ld Perca (PtTCi jliaiiiiis), una especie europea imroiiiiida els daen anys a CIII/IJIVI. La introucci de peixos

    E-print Network

    Garc铆a-Berthou, Emili

    u Ld Perca (PtTC铆i jliai铆iii铆is), una especie europea imroiiiiida els da帽en anys a C脥II脥I Ilac Victoria o Ukerewe, la introducci贸 d'un peix gran depredador, la perca del Nil (L眉tes n铆铆ot铆cus

  8. Especially for High School Teachers

    Microsoft Academic Search

    J. Emory Howell

    1999-01-01

    Chemistry and the Environment This issue contains more than 20 articles relating to the environment. Several articles of potential interest are indicated in the Table of Contents with the SSC mark (). Others are not so indicated because they depict use of expensive instrumentation or costly procedures, but if you have an interest in environmental chemistry you may wish to

  9. Especially for High School Teachers

    Microsoft Academic Search

    J. Emory Howell

    1999-01-01

    Care to Share? An Informal Syllabus Exchange A recent email message from Thomas Shiland, who teaches at Saratoga Springs Senior High School, noted that the process of revising the high school chemistry syllabus is underway in New York State. He expressed a strong interest in helping construct a chemistry syllabus that represents the best thinking about appropriate content. He wondered

  10. Especially for High School Teachers

    Microsoft Academic Search

    J. Emory Howell

    1999-01-01

    More Feature Articles This Month This issue contains a larger-than-usual number of Secondary School Chemistry feature articles (see side-bar). Mary Harris, who teaches in St. Louis, Missouri, and her student, Lauren Picard, contributed an account of student research on the cuprammonium rayon process (p 1512). In addition to being informative and interesting, the article provides a model for student-teacher interaction

  11. Especially for High School Teachers

    Microsoft Academic Search

    J. Emory Howell

    2000-01-01

    Ideas and Resources in This Issue This issue contains a broad spectrum of topics of potential interest to high school teachers, including chemical safety, history, demonstrations, laboratory activities, electrochemistry, small group learning, and instructional software. In his report on articles published recently in The Science Teacher, Steve Long includes annotated references from that journal, and also from JCE, that provide

  12. Especially for High School Teachers

    Microsoft Academic Search

    J. Emory Howell

    1999-01-01

    Secondary School Feature Articles * An Elementary Outreach Program-Have Demo Will Travel, by James Swim, p 628 * Pressure and Stoichiometry, by Charles E. Roser and Catherine L. McCluskey, p 638 Making Connections vs Relevance: Chemistry and Biology For many years there has been a movement to make chemistry more relevant to learners, particularly in introductory chemistry courses. Sidebars describing

  13. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2000-06-01

    It Was Nice to See You It was great to meet and talk to so many high school chemistry teachers who attended the High School Program at the ACS National Meeting in San Francisco or attended the NSTA National Convention in Orlando. Thank you to every teacher who visited the JCE Booth at either meeting and to the approximately 100 individuals who attended the JCE workshop early Monday morning at the ACS. At the NSTA meeting, the Mole Day Breakfast was a special occasion that was made very enjoyable by National Mole Day Foundation leaders Art Logan and Maury Oehler and the enthusiasm and camaraderie of the audience. For more about NMDF activities check out the website http://gamstcweb.gisd.k12.mi.us/~nmdf. Bringing Quality Visualization into the Classroom Turn to page 799 of this issue to learn about the release of Chemistry Comes Alive! Volume 4. The Chemistry Comes Alive! series of CD-ROMs are packed with Quicktime movies and still photos depicting chemical reactions, many of which are too hazardous or expensive to carry out in the classroom or laboratory. Many of the demonstrations are accompanied by background information, and they are also correlated with popular chemistry textbooks. An innovation appearing in Volume 4 is an interactive section on reactions in aqueous solution. Among the appealing features of the CCA! series is the ability to incorporate QuickTime movies of these demonstrations into your own presentations. The Reprise of Chemical Principles Revisited I am very pleased that Cary Kilner has agreed to edit the Chemical Principles Revisited feature. Please read his Mission Statement below. If you have an idea for a manuscript that fits this feature, now is the time to take action either by discussing it with Cary or by submitting a manuscript for review. This feature has the potential to be very useful to teachers, but it can reach its potential only through your suggestions and submissions. Let us hear from you soon. Scenes from High School Day at the ACS meeting in San Francisco. (Top photo, left to right) Carolyn Abbott, chair of the program, with Michael Tinnesand and Mare Taagepera. (Bottom photo) Michael Tinnesand speaking at the Luncheon. Photo by Morton Z. Hoffman. Mission Statement for Chemical Principles Revisited W. Cary Kilner, Feature Editor Exeter High School, 7 Salmon Street, Newmarket, NH 03857; 603/659-6825; CaryPQ@aol.com Through this feature, teachers are invited to share how they introduce and present a specific chemical principle, how students investigate the principle or its applications in the laboratory, and how student understanding of this principle is assessed. In most cases the principle would be one that is difficult for students to learn or apply, or one in which chemical research has led to a new understanding that has not yet appeared in textbooks. Discussion of content underlying the principle should provide insight that goes beyond the treatment of high school or general chemistry texts, providing depth that will enable the teacher to become confident in his or her understanding. The account may be a brief vignette that will inspire the reader to try something new and that can be easily implemented. Alternatively, it may be a longer discussion of phenomena that have been neglected or misinterpreted and to which a fresh, reflective, and informed view is provided. An example of a brief article is "The Disappearing Act: Teaching Students to Expect the Unexpected" (J. Chem. Educ. 1987, 64, 155). An example of a longer article is "Studying the Activity Series of Metals" (J. Chem. Educ. 1995, 72, 51), although a current submission should also include discussion of assessment and actual outcomes whenever possible. Teachers who have an idea for an article that fits this mission may contact the feature editor if they have questions.

  14. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2000-02-01

    Secondary School Feature Articles JCE Classroom Activity: #24. The Write Stuff: Using Paper Chromatography to Separate an Ink Mixture, p 176A Teaching Chemistry in the Midwinter Every year, forecasters around the world provide us with long-range predictions of what the seasons will afford us in the coming year. And each year, the weather provides a few surprises that the forecasters did not predict - such as a record amount of snow or record heat indexes, depending on where you live. Although the weatherman didn't predict it, we still must pull out our snow shovels or sun block and take the necessary steps to adapt to the situation. As teachers, we make predictions of teaching and learning goals that we aspire to achieve during a given year, and like the weather, the year brings surprises that aren't in line with our predictions. With that in mind, I would like to offer JCE as the scholastic snow shovel or sun shield you need to jump-start your class and reach the goals you have set. So find a warm (or cool) place, get comfortable, and spend some time with the February issue of JCE. Articles of General Interest in This Issue For readers living where snow falls, Williams's article on page 148 offers some historical background on the use of calcium chloride as a deicer. A diver that depends for its buoyancy upon gas given off by a chemical reaction is described by Derr, Lewis, and Derr in the article beginning on page 171. In her article appearing on pages 249-250, Wang describes a laboratory exercise that makes the mastery of solution preparation skills fun. The students' skill is tested by using the solutions they make to carry out the Briggs-Rauscher oscillating reaction. For high school class applications I recommend use of 3% hydrogen peroxide, described as an option in the article. A well-organized approach to separating an ink mixture, with some possibly new twists, is laid out in the student- and teacher-friendly format of JCE Classroom Activity: #24, pages 176A-176B. Addressing Some Specialized Interests As in any issue of the Journal, there are several articles that are not designated with the secondary school mark (?) but are likely to be of interest to some high school teachers. For example, if you are interested in staying abreast of educational applications of computational chemistry, the articles on pages 199-221 will be among those you will wish to examine even though the focus is on meeting the learning needs of college students. For those with an interest in electronics, there are several articles on pages 252-262, on building on modifying useful devices. Among the topics: building a digital monitor for analyzing spectrophotometer signals, building a digital interface for a graphing calculator, and using an inexpensive commercial analog-to-digital converter. JCE Reviewers The standard of quality in JCE articles is due in great measure to the careful scrutiny and helpful suggestions of reviewers. I am proud to note that the names of several high school teachers are in the list of individuals who have reviewed manuscripts for JCE recently. This month's list, which appears on page 152, is a continuation from page 24 of the January issue. Keep watching if your name has not yet appeared. If you are not currently serving as a reviewer, I encourage you to sign up today. As a reviewer, you would review potential articles that have been submitted to the Journal. You may choose from a variety of subject areas to review and choose as few or as many manuscripts as you can handle. To find out how to become a reviewer, read the information on page 162 or visit our Web site at jchemed.chem.wisc.edu/Journal/Reviewers. NACS 3/2000 Reminder NACS 3/2000 is the heading Carolyn Abbott uses in email correspondence about the High School Day program, which be held Monday, March 27, 2000, at the American Chemical Society National Meeting in San Francisco. Carolyn is High School Program Chair and she and her committee have assembled a full day of interesting and useful sessions for teachers. Among the sessions will be three worksh

  15. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-12-01

    Chemistry and the Environment This issue contains more than 20 articles relating to the environment. Several articles of potential interest are indicated in the Table of Contents with the SSC mark (). Others are not so indicated because they depict use of expensive instrumentation or costly procedures, but if you have an interest in environmental chemistry you may wish to examine all the environmentally related articles. While many of the articles, both marked and unmarked, are targeted to college-level environmental chemistry curricula or to introductory courses for non-major, the methods described in several could be readily adapted to high school chemistry courses. One article likely to be of interest to teachers is found in News from Online, pp 1608-1609. The author explains how to use the U.S. Environment Protection Agency's EnviroMapper Web site to view and query environmental information. She mentioned finding a hazardous waste handler located near her home, so I decided to check the area near my home. I quickly located a natural gas salt dome storage facility marked on the map and, with a few more mouse clicks, I found information that included status of compliance with regulations, amounts of each compound released to the air in tons per year, and how to contact the corporation owning the site. Email and Web site addresses were included for the convenience of anyone wishing to contact the corporation. Students could learn a great deal about where they live that is relevant to chemistry by using the EPA site. Additional Web sites dealing with environmental issues and chemistry are cited in the sidebar at the bottom of p 1609. Among the articles that could be adapted to an advanced high school chemistry class or possibly even to an introductory class is one titled Bridge of Mandolin County (pp 1671-1672). It describes a case-study strategy similar to the scenarios used in ChemStudy. Students analyze information from various sources, including laboratory experiments if desired, discuss their findings, and make a recommendation regarding which of two road deicers should be used on the bridge. The article Pesticides in Drinking Water: Project-Based Learning within the Introductory Chemistry Curriculum (pp 1673-1667) describes class involvement in field data collection and analysis. Since more sophisticated instrumentation than is possessed by many schools is required, 6th grade science and high school chemistry classes work with a college class to obtain and analyze data. Everyone involved in this approach wins. The 6th graders, high school students, and college students all gain experience in sampling, preparing samples for analysis, determining pollutant levels, and drawing conclusions, each at an appropriate level of understanding. Plus, the high school students are exposed to instrumentation that otherwise would not be accessible, such as gas chromatography coupled with mass spectrometry (GC-MS). Although the project described was started by the college faculty members who wrote the article, such an approach to many interesting environmental chemistry problems could be initiated by a high school teacher by seeking out a nearby college or university with whom to partner. An article that probably would not have received the SSC mark had I not noticed that two of the coauthors are high school students, is titled Remediation of Water Contaminated with an Azo Dye (pp 1680-1683). In addition to being interesting, the article is a good reminder that research opportunities for high school students exist. Still another article that received the SSC mark because of a high school connection is Chemical Analysis of Soils (pp 1693-1694). The authors mention that with modification their techniques could be used in high school chemistry. They cite a reference to an article published several years ago, titled Soil Analysis for High School Chemistry Students (J. Chem. Educ. 1980, 57, 897-899). It was published in a feature titled the 50-Minute Experiment. Block scheduling has brought

  16. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-02-01

    Secondary School Feature Articles * Building the Interest of High School Students for Science-A PACT Ambassador Program To Investigate Soap Manufacturing and Industrial Chemistry, by Matthew Lynch, Nicholas Geary, Karen Hagaman, Ann Munson, and Mark Sabo, p 191. * Promoting Chemistry at the Elementary Level, by Larry L. Louters and Richard D. Huisman, p 196. * Is It Real Gold? by Harold H. Harris, p 198. * The "Big Dog-Puppy Dog" Analogy for Resonance, by Todd P. Silverstein, p 206. * The Fizz Keeper, a Case Study in Chemical Education, Equilibrium, and Kinetics, by Reed A. Howald, p 208. Staying on Top: Curricular Projects, Relativistic Effects, and Standard-State Pressure You may wonder why some articles are identified with the Secondary School Chemistry logo (*) this month even though at first glance they appear to be of greater interest to college faculty.1 The three articles discussed below are representative of three broad categories: (i) the interrelatedness of science teaching and learning, K-16+; (ii) new understandings of chemical phenomena; and (iii) information about the use of SI units. For each article I have highlighted the major point(s) and the reasons it may be of interest to high school teachers. First, the article "The NSF 'Systemic' Projects- A New Tradition" (G. M. Barrow, p 158) is a commentary on changes in post-secondary introductory chemistry courses in which a distinction is drawn between information management and individual understanding. The author is of the opinion that most students expect the former and that the NSF-funded systemic projects "will thrive only if they are consistent with their information-management mission". Three individuals provided responses to the commentary from their perspective. Has a student asked you why mercury is a liquid, or why gold is the most electronegative metal? "Gold Chemistry: The Aurophilic Attraction" by J. Bardaj and A. Laguna (p 201) and "Why Gold and Copper Are Colored but Silver Is Not" by A. H. Guerreor, H. J. Fasoli, and J. L. Costa (p 200) provide useful information in answering these questions. Have you thought about the effect of changing the standard-state pressure from 1 atm to the SI unit of 1 bar? The question is addressed in "How Thermodynamic Data and Equilibrium Constants Changed When the Standard-State Pressure Became 1 Bar" by R. S. Treptow (p 212). The author points out that although textbook authors have not yet abandoned use of 1 atm as standard-state pressure, thermodynamic data are reported in the research literature on the basis of 1 bar standard-state pressure. The author provides the information needed to readily convert thermodynamic data from one standard to the other. These articles represent just a few that may be of interest to you. I encourage you to explore other articles within the Journal that are not noted with the secondary school section logo. As we each continue to broaden our knowledge of chemistry and chemical education, JCE will continue to serve as an invaluable resource in our educational quest. Anaheim and Boston in March; Fairfield in August JCE will have a booth in the exhibition hall both at the ACS National Meeting in Anaheim, March 21-24, and at the NSTA National Convention in Boston, March 25-29. Additionally, the all-day High School Program on Monday, March 22, will be held as part of the ACS meeting. More details will be provided in the March issue of JCE. Make your plans to attend now. Registration information may be found at http://www.acs.org/meetings/anaheim/welcome.htm and http://www.nsta.org/conv/natgen.htm. Another outstanding event, ChemEd '99, will held on the campus of Sacred Heart University, Fairfield, CT, August 1-5, 1999. Information, including a call for presentation proposals, is available at http://www.sacredheart.edu/chemed/. The deadline for abstracts is March 1, 1999, so don't delay. Chemistry for Kids-Looking for New Ideas Over the life of the Chemistry for Kids (CFK) feature a relatively large number of articles have

  17. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Emory Howell, J.

    1999-11-01

    More Feature Articles This Month This issue contains a larger-than-usual number of Secondary School Chemistry feature articles (see side-bar). Mary Harris, who teaches in St. Louis, Missouri, and her student, Lauren Picard, contributed an account of student research on the cuprammonium rayon process (p 1512). In addition to being informative and interesting, the article provides a model for student-teacher interaction in carrying out an independent research project. Two North Carolina teachers, Charles Roser and Catherine McCluskey, describe how to use a Calculator Based Laboratory (interface) to measure the kinetics of the reaction that occurs when a lightstick is activated (p 1514). The method and the easy-to-construct device they made could be used with other systems, as well. Don't Throw Away the Carrier Sheet All areas of JCE Online are now accessible to all JCE subscribers. To find out how you can benefit, read the article appearing on p 1599, Now That I Have It, What Can I Do with It? Jon Holmes, Editor of JCE Online, explains in the article how you can use this resource most effectively. Access to several areas, such as full text access to articles, requires that you log in. The mailing label on the carrier sheet that accompanies your Journal each month contains a password that you need to log in. That is why you need to keep the carrier sheet, at least until you have logged in for the first time and either memorized the number or written it in a safe place. Detailed instructions for logging on are found by clicking on the "How to Log On" link, which appears near the upper left corner of the JCE Online Home Page, jchemed.chem.wisc.edu. If you read a school library copy you need to ask your librarian what password you need to log in. Congratulations Among the recipients of the most prestigious American Society Awards (p 1481) are two individuals who have given generously of their time and energy to the cause of chemical education. Both are familiar names to many of our readers. The High School/College Interface Luncheon was part of the very rich day-long High School Program at the New Orleans ACS Meeting. Shown here (from left) are Glenn Crosby, the luncheon speaker; Lillie Tucker-Akin, the High School Day program chair; and Fred Johnson, Assistant Superintendent of Shelby County (TN) schools and Immediate Past President of NSTA. The recipient of the James Bryant Conant Award in High School Chemistry Teaching is Frank G. Cardulla, who taught for many years at Niles North High School, Skokie, Illinois. His extensive record of service to fellow teachers includes editing the JCE "View from My Classroom" feature for several years and writing several articles, as well as his recent appointment to the JCE Board of Publication. The recipient of the George C. Pimentel Award in Chemical Education is Jerry A. Bell of the American Chemical Society in Washington, DC. An author of numerous articles appearing in JCE and a member of the JCE Board of Publication for several years, he currently serves as Board Chair. The 16th Biennial Conference on Chemical Education Readers who attended the 15th BCCE in Waterloo, Ontario, know that much of the programming at these conferences is of interest to high school teachers. Many work shops, papers, and demonstrations are presented by high school teachers. There are many other outstanding papers and posters, plenary speakers, and exciting demonstrations. The 16th BCCE will be held at the University of Michigan in Ann Arbor, July 30-August 3, 2000. Among the high school teachers already scheduled to present workshops at the 16th BCCE are George Hague, Lynn Hershey, and Jack Randall, and there will be many more before the program is completed. The High School Chemistry Program Chair is Tim Graham, Roosevelt High School (MI). The Organizing Committee is seeking the assistance of local sections of the American Chemical Society within a 300-mile radius of

  18. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2001-10-01

    JCE publications regularly make connections to a wide variety of interests, of which art is but one. Interdisciplinary Connections is a High School Feature Column designed to meet this challenge. Articles have been published relating literature (2) and writing (3) to chemistry. If you have developed interdisciplinary connections that you would like to share with other teachers, I encourage you to contact the feature editor, Mark Alber.2 Additional examples of annotated bibliographies on chemical connections to other disciplines or applications include food science (4), environmental concerns (5), and writing (6,7). The online "Search" link in the left-hand column of the home page of HS CLIC can lead to the discovery of articles relevant to many other interests. Happy connecting!

    Note

    1. For more information about NCW, visit their Web site.
    2. For the feature mission statement and contact information see the HS CLIC Web site.

    Literature Cited

    1. Chem. Eng. News 2001, 79 (Feb 26), 50.
    2. Thoman, C. J. J. Chem. Educ. 1998, 75, 495.
    3. Alber, M. J. Chem. Educ. 2001, 78, 478.
    4. Jacobsen, E. K. J. Chem. Educ.2000, 77, 1256.
    5. Moore, J. W.; Moore, E. A. J. Chem. Educ. 1976, 53, 167; 1976, 53, 240; 1975, 52, 288.
    6. Shires, N. P. J. Chem. Educ. 1991, 68, 494.
    7. Waterman, E. L. J. Chem. Educ. 1981, 58, 826.

  19. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-04-01

    Secondary School Feature Articles * Amino Acid Wordsearch, by Terry L. Helser, p 495. Games, Puzzles, and Humor In honor of April Fools' Day this issue contains 22 pages devoted to games and puzzles that can be used to teach aspects of chemistry. Most are designed for high school and first-year college students. The lead article, p 481, contains an annotated bibliography of chemistry games, complete with a vendor list. Many of the annotated games must be purchased, but the other articles that follow in this issue describe some games and puzzles that require minimal preparation using a word processor and readily available materials. Actually, JCE has a long tradition of publishing games and puzzles for chemistry teachers and their students. Read the letter by Helser and the Editor's response, p 468, for some recent background. Not having counted articles over past years, I became curious and turned to the online index, accessed by way of http://jchemed.chem.wisc.edu/. Because I wanted to search the entire 75-year life of the Journal, I searched titles for the words "game", "puzzle", and "humor" and obtained a total of 85 hits from the three searches. After eliminating titles of articles that were not applicable, I found that at least 25 games, 48 puzzles, and 5 humor articles have appeared during the past 75 years. At an average of one per year, the JCE editors hardly can be accused of frivolity, but game, puzzle, and humor articles have been published. The term "game" did not appear in any titles during 1945-1970, "puzzle" did not appear from 1927 to 1953, and there was no mention of humor (in the titles) prior to 1974. What appears to be the earliest article (1929) about a game was authored by an undergraduate student at the University of Colorado (1). It was titled "Chemical Bank", and the game pieces were tokens cut from cork stoppers. Wire hooks were inserted in the side of the token to represent valence electrons available for bonding. Carbon contained 4 hooks at 90 relative to each other, nitrogen contained three hooks at 120, etc. The wires were sufficiently long and flexible that multiple bonding could be represented. Each player was dealt several game pieces and the first player received an extra carbon. The objective was to hook pieces together to make an acceptable molecule. Players took turns and the first player to use all his or her pieces was declared the winner. The first crossword puzzle to appear in JCE was written by a high school teacher from Hollywood, California (2). Ruth Van Vleet had observed that her students were caught up in the popularity of crossword puzzles of the time (1925) and used that interest to help students learn chemical facts. The puzzle published in the article was submitted by one of her students after completing one year of chemistry. The first article which carried the term "humor" in the title was published in 1974 (3). To meet the requirements of a class assignment to compare two elements, one student wrote an imaginary dialog between ytterbium and lutetium. Word play and puns were used to described similar and differing properties of the two elements. This article, however, was not the first account of using humor as a vehicle for stimulating student interest. Games, puzzles, and humor certainly can be overused. Usually they do not lead to the development of conceptual understanding. However, appropriate use, as many JCE readers have discovered, can stimulate student interest and reinforce factual knowledge. Some strategy games may help develop problem-solving and critical-thinking skills. The games, humor, and puzzles published in JCE are peer-reviewed so that inaccuracies and errors are not perpetuated. So why not take advantage of this resource? And look forward to next April, or whenever, for more games, puzzles, and humor. Feedback Requested for View from My Classroom Feature David Byrum, editor of the View From My Classroom feature, requests the assistance of readers. During a recent conference o

  20. Especially for High School Teachers

    Microsoft Academic Search

    J. Emory Howell

    2000-01-01

    Alternative Assessment The trend in several states to use high-stakes achievement test scores to evaluate districts, schools, and teachers appears to be at odds with the intent of the National Science Education Assessment Standards. Recently I read several postings on an Internet discussion list in which several high school teachers expressed differing opinions on how to deal with the situation.

  1. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2000-09-01

    Alternative Assessment The trend in several states to use high-stakes achievement test scores to evaluate districts, schools, and teachers appears to be at odds with the intent of the National Science Education Assessment Standards. Recently I read several postings on an Internet discussion list in which several high school teachers expressed differing opinions on how to deal with the situation. There seemed to be general agreement, however, that as increased emphasis is placed on preparation for high-stakes end-of-course examinations it becomes more difficult to assess conceptual understanding. High school chemistry teachers are an innovative lot, and I am confident that ways will be found to evaluate understanding no matter what. This month's issue contains two examples of using student-constructed posters as a means of assessment. Although we most often associate poster presentations with research, such as a science fair project, these articles show that posters may also be used to assess student learning in class settings. The examples are from lower-division college courses, but they may be equally useful in high school chemistry courses. An article titled Using Poster Sessions as an Alternative to Written ExaminationsThe Poster Exam by Pamela Mills and four co-authors contains a detailed explanation of how student-constructed posters can be used to assess student learning. A number of related articles are listed in the Literature Cited section. Another example is found in A Poster Session in Organic Chemistry That Markedly Enhanced Student Learning by P. A. Huddle. The same author also contributed the article How to Present a Paper or Poster in which useful, straightforward suggestions for communicating information and ideas clearly are provided.

  2. Especially for Teens: Birth Control

    MedlinePLUS

    ... estrogen, which controls the function of female reproductive organs. Human Immunodeficiency Virus (HIV): A virus that attacks certain cells of the body抯 immune system and causes acquired immunodeficiency syndrome ... organs. Penis: An external male sex organ. Sexually Transmitted ...

  3. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-08-01

    Care to Share? An Informal Syllabus Exchange A recent email message from Thomas Shiland, who teaches at Saratoga Springs Senior High School, noted that the process of revising the high school chemistry syllabus is underway in New York State. He expressed a strong interest in helping construct a chemistry syllabus that represents the best thinking about appropriate content. He wondered if it would be possible to develop a way in which different secondary chemistry syllabi could easily be exchanged. It is likely that readers from other states and countries are involved in a similar process and might also be interested in exchanging syllabi. Many states do not use the term syllabus to describe their guiding curricular document for chemistry but rather refer to it as a framework or as guidelines. In most cases, the document includes a list of key ideas or topics, performance indicators, and the major understandings associated with each key idea. Such documents would be appropriate for exchange among those of you involved in the revision process. If you are interested in arranging an exchange please contact me by email at j.e.howell@usm.edu or by mail at J. E. Howell, Box 5043, USM, Hattiesburg, MS39406-5043, USA. High School Day Information The High School Chemistry Program at the American Chemical Society National Meeting in New Orleans, Louisiana will be held Sunday, August 22, 1999, at the Doubletree Hotel, 300 Canal Street. If you wish to register only for the High School Day activities, which includes a pass to the ACS Exposition, a special registration form is available from Lillie Tucker-Akin, 2800 Reynard Dr., Tupelo, MS38801; sci4me@aol.com; fax: 662/566-7906. Advance registration is 25 and the cost of the High School Luncheon is 12. Register in advance by August 1, 1999, or from 7:45 to 8:30 a.m. at the High School Day table in the conference room area of the Doubletree. The workshop schedule is shown below. Secondary School Feature Articles * Exploring the Ocean-Stating the Case for Chemistry, by Paul J. Scheuer, p 1075 * Distillation Apparatuses Using Household Items, by Danielle R. D. Campanizzi, Brenda Mason, Christine K. F. Hermann, p 1079 New Orleans Concurrent Workshops, High School Program 8:30 a.m.-9:20 a.m. A. A Teaching Resource for You: The Journal of Chemical Education, J. E. Howell, J. W. Moore, and A. M. Sarquis B. Electrical Conductivity, J. M. Manion and P. F. Krause, and The Properties of Gases, J.-M. Whitfield and K. A. Woodling C. Chemistry with Calculators for Beginners, P. Sconzo (3 hours) D. Spectrum of Activities for Chemistry Teachers, Carolina Biological Supply, S. Mitchell, F. Cherry, and L. Akin (3 hours) 9:30 a.m.-10:20 a.m. A. Applying Chemical Education Research to the Classroom, L. Akin and J. Valasek B. Another Look at the Deflection of Falling Liquids, H. H. Harris and J. Newstrum, and Encouraging Students to Investigate Acids and Bases Using Plant Indicators, P. K. Kerrigan C. Chemistry with Calculators (continued) D. Spectrum of Activities (continued) E. Science Education for Public Understanding (SEPUP) and Chemistry, Health, Environment, and Me, M. Koker and L. Akin (2 hours) 10:30 a.m.-11:30 a.m. A. Increasing Aptitude and Interest of High School Students through Summer Camp, C. E. Fulton, and Energy Teaching Introduction to High School Chemistry, L.-M. Trejo B. Chemistry in Science Museum Exhibits: Opportunities and Challenges and Cooking with Chemistry, D. Katz C. Chemistry with Calculators (continued) D. Spectrum of Activities (continued) E. SEPUP (continued) 12:00 noon-1:15 p.m., High School Luncheon Educating High School Teachers for the 21st Century, Glenn Crosby 1:30 p.m.-2:20 p.m. A. Customized Mastery Learning in First-Year Chemistry and Computer Software for Chemistry Teachers Who Require Mastery Learning of Their Students, J. Bedenbaugh and A. Bedenbaugh B. Can One Teach Chemistry with Everyday Substances? A. Sae, and SourceBook Activities Using Everyday Substances, C. Ayers, J

  4. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-10-01

    Writing Across the Curriculum The notion that student learning is enhanced through writing is widely accepted at all educational levels if the product is fairly assessed and the learner is provided with feedback. Finding the time to critically evaluate student papers is difficult at best and competes with time needed to prepare laboratory investigations. A few weeks ago a teacher who has extensive extracurricular responsibilities that include extensive interaction with parents and community members shared with me his frustration in not being able to grade written reports. This teacher is the head football coach at his school, but many readers experience the same difficulties due to a variety of duties. There are no easy or completely satisfying answers to this problem, but this issue contains an account of a successful approach (Writing in Chemistry: An Effective Learning Tool, pp 1399-1403). Although they are based on experience in college courses, several ideas described in the article could be applied in high school chemistry courses. In another article, the author of Precise Writing for a Precise Science (pp 1407-1408) identifies 20 examples of familiar, but incorrect, grammatical constructions and explains how to phrase each one correctly. Chemical Education Research: Improving Chemistry Learning The results from research on how students learn have greatly increased our understanding of cognition in recent years. However, the results are often published in the science education research literature and are not readily accessible to the classroom teacher. Additionally, the research reports are couched in specialized terminology. This issue contains a Viewpoints article (pp 1353-1361) that bridges the gap between research results and classroom application. It was written by two veteran chemical educators, Dudley Herron and Susan Nurrenbern. The shift from behaviorism to constructivism as the dominant theory of learning is described briefly to provide a context for constructivist approaches. In the section titled "What Research Has Revealed", the authors provide a succinct summary of specific research findings under three tantalizing subheadings: "What You Think You Know May Not Be the Way It Is", "Learning Is Not a Spectator Sport!", and "Appropriate Outcomes Must Be Identified and Measured". The authors' insight into future research challenges is detailed in a sidebar. ChemEd'99: A Great Success The 1999 ChemEd Conference was a great success, judging by the many very favorable comments of high school teachers who attended. Thanks and congratulations go to Babu George and to the many volunteers who made this event possible through a great deal of hard work, ingenuity, and creativity. Many of the volunteers who gave so generously of their time, before and during the conference, are high school teachers. The program reflected the broad range of needs and interests of high school teachers. Credit for the success also should go to the many presenters. The workshops, demonstrations, papers, and posters that I attended were of high quality and useful to teachers. Conversation with other attendees convinced me that the same degree of quality and utility was characteristic of the entire conference program. Demonstrations are always an outstanding feature of ChemEd conferences and the Signature Demonstrations continued this tradition, as did the large number of demonstration sessions scheduled throughout the general program. The Reg Friesen Memorial Lecture, delivered by Steve Spangler, featured spectacular and stimulating demonstrations in the context of building connections between chemical concepts and real-world applications. Some other themes that permeated the general program were Internet applications, methods of assessment, safety and waste disposal, calculator and computer based laboratory methods, and ideas for making classroom instruction interesting and effective. Thank you to each reader who visited the JCE Exhibit or participated in our workshop on using JCE Activities. We e

  5. Especially for High School Teachers

    Microsoft Academic Search

    J. Emory Howell

    1999-01-01

    Secondary School Feature Article * JCE Classroom Activity #18: Photochemistry and Pinhole Photography: An Interdisciplinary Experiment, by Angeliki A. Rigos and Kevin Salemme, p 736A High School Program at Anaheim ACS Meeting Congratulations to Barbara Sitzman of Chatsworth High School (Los Angeles) and her committee for organizing an outstanding day of activities! With support from the Southern California Section of

  6. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2000-10-01

    Garfield, the feline creation of comic strip artist Jim Davis, hates Mondays with a passion. Many individuals-including chemistry teachers and their students-can identify with Garfield's animosity toward Mondays. But October 23 is a Monday that everyone should look forward to because it is Mole Day. This year's theme is Celebrate the MOLEnnium, and as anticipated, CEO Maury Oheler, President Art Logan, and the foundation board members have done their usual great job of planning an event for building student interest. Check out the National Mole Day Foundation Web site to find more information about the MOLEnnium Celebration and obtain a membership form so that you may obtain the full packet of Mole Day activities. If you do not have access to the Web, you may send 15 new membership (or 10 renewal) with your name, address, telephone number, and email address to National Mole Day Foundation, Inc., 1220 South 5th Street, Prairie du Chien, Wisconsin 53821.

  7. Patentability of Research Results in Connection with Human-Embryonic Stem Cells, especially with the So-Called Therapeutic Cloning Chinese Points of View

    Microsoft Academic Search

    Tang Guangliang

    Due to the huge market potential in the stem cell research field, especially in the field of embryonic stem cell research,\\u000a some scientists have predicted that effective stem cell treatment for diabetes, liver and blood diseases, Alzheimer disease,\\u000a etc. will go to clinical practice in the near future. According to reports, the potential market return of stem cell treatment\\u000a will

  8. Single-walled carbon nanohorn (SWNH) aggregates inhibited proliferation of human liver cell lines and promoted apoptosis, especially for hepatoma cell lines

    PubMed Central

    Zhang, Jinqian; Sun, Qiang; Bo, Jian; Huang, Rui; Zhang, Mengran; Xia, Zhenglin; Ju, Lili; Xiang, Guoan

    2014-01-01

    Single-walled carbon nanohorns (SWNHs) may be useful as carriers for anticancer drugs due to their particular structure. However, the interactions between the material itself and cancerous or normal cells have seldom been studied. To address this problem, the effects of raw SWNH material on the biological functions of human liver cell lines were studied. Our results showed that unmodified SWNHs inhibited mitotic entry, growth, and proliferation of human liver cell lines and promoted their apoptosis, especially in hepatoma cell lines. Individual spherical SWNH particles were found inside the nuclei of human hepatoma HepG2 cells and the lysosomes of normal human liver L02 cells, implying that SWNH particles could penetrate into human liver cells_and the different interacted mechanisms on human normal cell lines compared to hepatoma cell lines. Further research on the mechanisms and application in treatment of hepatocellular carcinoma with SWNHs is needed. PMID:24523586

  9. Computed Tomography Imaging Spectrometer (CTIS) with 2D Reflective Grating for Ultraviolet to Long-Wave Infrared Detection Especially Useful for Surveying Transient Events

    NASA Technical Reports Server (NTRS)

    Wilson, Daniel W. (Inventor); Maker, Paul D. (Inventor); Muller, Richard E. (Inventor); Mouroulis, Pantazis Z. (Inventor)

    2003-01-01

    The optical system of this invention is an unique type of imaging spectrometer, i.e. an instrument that can determine the spectra of all points in a two-dimensional scene. The general type of imaging spectrometer under which this invention falls has been termed a computed-tomography imaging spectrometer (CTIS). CTIS's have the ability to perform spectral imaging of scenes containing rapidly moving objects or evolving features, hereafter referred to as transient scenes. This invention, a reflective CTIS with an unique two-dimensional reflective grating, can operate in any wavelength band from the ultraviolet through long-wave infrared. Although this spectrometer is especially useful for events it is also for investigation of some slow moving phenomena as in the life sciences.

  10. Computed tomography imaging spectrometer (CTIS) with 2D reflective grating for ultraviolet to long-wave infrared detection especially useful for surveying transient events

    NASA Technical Reports Server (NTRS)

    Wilson, Daniel W. (Inventor); Maker, Paul D. (Inventor); Muller, Richard E. (Inventor); Mouroulis, Pantazis Z. (Inventor)

    2003-01-01

    The optical system of this invention is an unique type of imaging spectrometer, i.e. an instrument that can determine the spectra of all points in a two-dimensional scene. The general type of imaging spectrometer under which this invention falls has been termed a computed-tomography imaging spectrometer (CTIS). CTIS's have the ability to perform spectral imaging of scenes containing rapidly moving objects or evolving features, hereafter referred to as transient scenes. This invention, a reflective CTIS with an unique two-dimensional reflective grating, can operate in any wavelength band from the ultraviolet through long-wave infrared. Although this spectrometer is especially useful for rapidly occurring events it is also useful for investigation of some slow moving phenomena as in the life sciences.

  11. Making a good impression, especially during your first few weeks in a new situation, is important to your success. Following the tips below will enhance your confidence, professionalism, and

    E-print Network

    Kaminsky, Werner

    Making a good impression, especially during your first few weeks in a new situation, is important the rights and privacy of others Silence your cell phone Maintain good boundaries Cautious: Observe all" Don't date coworkers 颅 especially during your first few weeks Making a Good Impression #12

  12. Hormonal interference with pheromone systems in parasitic acarines, especially ixodid ticks. Annual technical report No. 4, 1 May 1983-30 April 1984

    SciTech Connect

    Sonenshine, D.E.; Oliver, J.H. Jr.; Homsher, P.J.

    1984-05-01

    The most important result of recent project research was the demonstration of the juvenoid JH III by radioimmunoassay. This assay revealed an estimated 78 pg/tick in the hemolymph of partially fed Hyalomma dromedarii females, and an estimated 3 pg/tick in the hemolymph of partially fed D. variabilis. Other studies, especially digestion of tritium labelled JH III, provided additional evidence suggesting the presence of this hormone in adult ticks. The implications of these findings for our understanding of sex pheromone regulation in ticks is discussed. Other studies described in this report deal with the source of ecdysteroid in teh camel tick, Hyalomma dromedarii, the American dog tick, Dermacentor variabilis, and the soft tick, Ornithodoros parkeri. Studies done at ODU, using radioimmunoassay high performance liquid chromatography, and autoradiography, provide new evidence implicating the tick synganglion - lateral nerve plexus as an important site of ecdysteroid activity in the ixodid ticks. Other studies with ecdysteriods suggest that metabolism of ecdysone or 20-hydroxyecdysone (or both) to inactive metabolites, possibly including polar conjugates. If confirmed, these findings indicate the presence of only a single active ecdysteriod hormone in ticks, 20-hydroxyecdysone.

  13. Platelet-Rich Plasma, Especially When Combined with a TGF-? Inhibitor Promotes Proliferation, Viability and Myogenic Differentiation of Myoblasts In Vitro

    PubMed Central

    Kelc, Robi; Trapecar, Martin; Gradisnik, Lidija; Rupnik, Marjan Slak; Vogrin, Matjaz

    2015-01-01

    Regeneration of skeletal muscle after injury is limited by scar formation, slow healing time and a high recurrence rate. A therapy based on platelet-rich plasma (PRP) has become a promising lead for tendon and ligament injuries in recent years, however concerns have been raised that PRP-derived TGF-? could contribute to fibrotic remodelling in skeletal muscle after injury. Due to the lack of scientific grounds for a PRP -based muscle regeneration therapy, we have designed a study using human myogenic progenitors and evaluated the potential of PRP alone and in combination with decorin (a TGF-? inhibitor), to alter myoblast proliferation, metabolic activity, cytokine profile and expression of myogenic regulatory factors (MRFs). Advanced imaging multicolor single-cell analysis enabled us to create a valuable picture on the ratio of quiescent, activated and terminally committed myoblasts in treated versus control cell populations. Finally high-resolution confocal microscopy validated the potential of PRP and decorin to stimulate the formation of polynucleated myotubules. PRP was shown to down-regulate fibrotic cytokines, increase cell viability and proliferation, enhance the expression of MRFs, and contribute to a significant myogenic shift during differentiation. When combined with decorin further synergistc effects were identified. These results suggest that PRP could not only prevent fibrosis but could also stimulate muscle commitment, especially when combined with a TGF-? inhibitor. PMID:25679956

  14. A cladistic phylogeny of the family Patellidae (Mollusca: Gastropoda)

    PubMed Central

    Ridgway, S. A.

    1998-01-01

    A phylogenetic hypothesis for the patellid limpets is reconstructed by cladistic analysis of morphological characters from 37 species, representing all but one of the living members of the family. Characters included in the analysis are derived from shell shape and microstructure, headfoot and pallial complex, radula and sperm. The species fall into four clades, providing the basis for a new phylogenetic classification into four monophyletic genera: Helcion (four species; southern Africa), Cymbula (eight species; southern Africa, eastern Atlantic, southern Indian Ocean), Scutellastra (17 species; southern and southwestern Africa, Australia, Indo-West Pacific, Eastern Pacific) and Patella (nine species; northeastern Atlantic and Mediterranean). The analysis suggests sister-group relationships between Helcion and Cymbula, and between Scutellastra and Patella. In combination with present-day patterns of geographical distribution, this phylogenetic hypothesis is used to discuss the historical biogeography of the Patellidae. Scutellastra may have originated in southern Africa and dispersed across the Pacific, or alternatively may be a primitively Tethyan group. Both Helcion and Cymbula appear to have originated in southern Africa, but three Cymbula species have dispersed respectively to northwest Africa, St Helena and the southern Indian Ocean. The patellids of the northeastern Atlantic form a single clade, Patella (including P. pellucida), which may have arrived by northward dispersal of an ancestor from southern Africa, or possibly by vicariance of a widespread ancestral Tethyan distribution. The known fossil record of patellids is too fragmentary to permit choice between these alternatives.

  15. Intramantle Inking: A Stress Behavior in Octopus bimaculoides (Mollusca: Cephalopoda)

    PubMed Central

    Toll, Ronald B

    2011-01-01

    Several Pacific 2-spot octopuses (Octopus bimaculoides) shipped from California and held in a recirculating seawater system at Illinois College exhibited an unusual postshipping stress behavior not previously documented in the literature. Ink, normally ejected into the surrounding seawater, was uncharacteristically retained in the mantle cavity. We describe the resulting behaviors, discuss successful resuscitation efforts, and briefly consider the possible role(s) that ink may have played in the death of one octopus. PMID:22330791

  16. Diversity of Indo-West Pacific Siphonaria (Mollusca: Gastropoda: Euthyneura).

    PubMed

    Dayrat, Beno顃; Goulding, Tricia C; White, Tracy R

    2014-01-01

    Species of the limpet genus Siphonaria (Gastropoda: Euthyneura) are commonly found in the rocky intertidal, worldwide, except in the Arctic. In total, 205 species-group names are available and not permanently invalid. However, estimating the actual species diversity of Siphonaria has remained challenging, mainly because past authors have interpreted differently the variation of shell characters, resulting in different taxonomic accounts. Species diversity of Siphonaria is evaluated for the first time here based on DNA sequence data (three mitochondrial gene fragments: COI, 12S, and 16S) and a large sampling focusing on the tropical and subtropical Indo-West Pacific (from eastern Africa to Hawaii): new sequences are provided for 153 individuals, 123 of which were collected from 93 locations throughout the Indo-West Pacific. In total, 41 species (molecular units) are recognized worldwide (31 from the Indo-West Pacific), all of which are strongly supported. Potential names are discussed for those 41 species, based on traditional taxonomy. The shells of 66 of the individuals from which DNA was extracted are illustrated: intra- and inter-specific variation is documented in detail and discussed in the light of new molecular results. It is shown that many species could hardly be identified based on the shell only, because the variation of shell characters is too high and overlaps between species. Geographically, no species is found across the entire Indo-West Pacific, where quite a few species seem to be endemic to restricted areas. The biogeography of Siphonaria in the Indo-West Pacific is compared to other groups. PMID:24871723

  17. Bacterial symbiosis in Loripes lucinalis (Mollusca: Bivalvia)with comments

    E-print Network

    Boyer, Edmond

    Symbiotic chemoautotrophic bacteria occur in the tissues of a number of invertebrates where sulphide or not the host can vary its nutritional dependence on the symbiotic bacteria. Obtaining clear answers-cellular sulphur-oxidizing bacteria within its gills, was studied between September 1991 and September 1992

  18. FEMALE CHOICE OF MALES IN CUTTLEFISH (MOLLUSCA: CEPHALOPODA)

    E-print Network

    Boal, Jean

    )andby the NationalResourceCenterfor Cephalopods (DHHS grant # RROIO24)at the Marine Biomedical Institute aboutthereproductivestrategiesof cephalopods.Evidence for assessmentsof rivals by males(Tinbergen,1939;Adamo & Hanlon, 1996;Di individuals (pers. obs.; seealso Adamo & Hanlon, 1996). We . know nothingaboutmatechoicein cephalopods,bu

  19. Upper Cambrian chitons (Mollusca, polyplacophora) from Missouri, USA

    USGS Publications Warehouse

    Pojeta, J., Jr.; Vendrasco, M.J.; Darrough, G.

    2010-01-01

    Numerous new specimens reveal a greater presence of chitons in Upper Cambrian rocks than previously suspected. Evidence is presented showing that the chiton esthete sensory system is present in all chiton species in this study at the very beginning of the known polyplacophoran fossil record. The stratigraphic occurrences and paleobiogeography of Late Cambrian chitons are documented. The 14 previously-named families of Cambrian and Ordovician chitons are reviewed and analyzed. Aulochitonidae n. fam. is defined, based on Aulochiton n. gen.; A. sannerae n. sp. is also defined. The long misunderstood family Preacanthochitonidae and its type genus Preacanthochiton Bergenhayn, 1960, are placed in synonymy with Mattheviidae and Chelodes Davidson & King, 1874, respectively; Eochelodes Marek, 1962, also is placed in synonymy with Chelodes, and Elongata Stinchcomb & Darrough, 1995, is placed in synonymy with Hemithecella Ulrich & Bridge, 1941. At the species level, H. elongata Stinchcomb & Darrough, 1995, and Elongata perplexa Stinchcomb & Darrough, 1995, are placed in synonymy with H. eminensis Stinchcomb & Darrough, 1995. The Ordovician species H. abrupta Stinchcomb & Darrough, 1995, is transferred to the genus Chelodes as C. abrupta (Stinchcomb & Darrough, 1995). The Ordovician species Preacanthochiton baueri Hoare & Pojeta, 2006, is transferred to the genus Helminthochiton as H. ? baueri (Hoare & Pojeta, 2006). The Ordovician species H. marginatus Hoare & Pojeta, 2006, is transferred to the genus Litochiton as L. marginatus (Hoare & Pojeta, 2006). Matthevia walcotti Runnegar, Pojeta, Taylor, & Collins, 1979, is treated as a synonym of Hemithecella expansa Ulrich & Bridge, 1941. In addition, other multivalved Cambrian mollusks are discussed; within this group, Dycheiidae n. fam. is defined, as well as Paradycheia dorisae n. gen. and n. sp. Cladistic analysis indicates a close relationship among the genera here assigned to the Mattheviidae, and between Echinochiton Pojeta, Eernisse, Hoare, & Henderson, 2003, and mattheviids. The results suggest treating these taxa as stem-lineage chitons, and do not support the hypothesis that they are aplacophorans.

  20. Distance chemoreception in the common cuttlefish, Sepia officinalis (Mollusca, Cephalopoda)

    Microsoft Academic Search

    J. G Boal; D. K Golden

    1999-01-01

    Cephalopods are highly visual animals; the importance of chemical perception to these complex mollusks is less well understood. In this experiment, ventilation rate was used to measure the perception of chemical stimuli by cultured juvenile cuttlefish. The test tank had opaque sides and top to visually isolate the cuttlefish. A clear bottom permitted direct observation of funnel movements associated with

  1. Neuronal localization of dopamine and 5Hydroxytryptamine in some mollusca

    Microsoft Academic Search

    Erik Dahl; Bengt Falck; Claes Mecklenburg; Harry Myhrberg; Evald Rosengren

    1966-01-01

    The localization of biogenic monoamines in ganglionic tissues from Anodonta piscinalis, Helix pomatia, and Buccinum undatum has been studied by means of the histochemical fluorescence method of Falck and Hillarp.

  2. STUDIES ON THE BEHAVIOR OF NASSARIUS OBSOLETUS (SAY) (MOLLUSCA, GASTROPODA)

    Microsoft Academic Search

    MARY CRISP

    Nassarius obsoletus (Say), the American mud snail, is an active and abundant prosobranch on the east coast of the United States of America. It is commonest on muddy shores where streams render the water brackish. C. E. Jenner, in a series of short abstracts (1956, 1957, 1958 and 1959) has described the way in which up to several thousand of

  3. RECENT MOLLUSCA OF ARKANSAS WITH ANNOTATIONS TO SYSTEMATICS AND ZOOGEOGRAPHY

    Microsoft Academic Search

    MARK E. GORDON

    A total of 223 taxa of Molluscaare presently known from Arkansas.The geological history and geomorphology of the region, particularly the presence of the Interior Highlands, have been responsible for the development of a diversemolluscan fauna.Thirtyregionally endemic formsare includedamong the 107 terrestrial gastropods, 36 aquatic gastropods, 65 unionacean mussels, and15 sphaeriacean clams.

  4. Biodiversity and biogeography of Antarctic and subAntarctic mollusca

    Microsoft Academic Search

    Katrin Linse; Huw J. Griffiths; David K. A. Barnes; Andrew Clarke

    2006-01-01

    For many decades molluscan data have been critical to the establishment of the concept of a global-scale increase in species richness from the poles to the equator. Low polar diversity is key to this latitudinal cline in diversity. Here we investigate richness patterns in the two largest classes of molluscs at both local and regional scales throughout the Southern Ocean.

  5. Miocene Vetigastropoda and Neritimorpha (Mollusca, Gastropoda) of central Chile

    NASA Astrophysics Data System (ADS)

    Nielsen, Sven N.; Frassinetti, Daniel; Bandel, Klaus

    2004-09-01

    Species of Vetigastropoda (Fissurellidae, Turbinidae, Trochidae) and one species of Neritimorpha (Neritidae) from the Navidad area, south of Valpara?磗o, and the Arauco Peninsula, south of Concepci髇, are described. Among these, the Fissurellidae comprise Diodora fragilis n. sp., Diodora pupuyana n. sp., two additional unnamed species of Diodora, and a species resembling Fissurellidea. Turbinidae are represented by Cantrainea sp., and Trochidae include Tegula (Chlorostoma) austropacifica n. sp., Tegula (Chlorostoma) chilena n. sp., Tegula (Chlorostoma) matanzensis n. sp., Tegula (Agathistoma) antiqua n. sp., Bathybembix mcleani n. sp., Gibbula poeppigii [Philippi, 1887] n. comb., Diloma miocenica n. sp., Fagnastesia venefica [Philippi, 1887] n. gen. n. comb., Fagnastesia matanzana n. gen. n. sp., Calliostoma mapucherum n. sp., Calliostoma kleppi n. sp., Calliostoma covacevichi n. sp., Astele laevis [Sowerby, 1846] n. comb., and Monilea riorapelensis n. sp. The Neritidae are represented by Nerita (Heminerita) chilensis [Philippi, 1887]. The new genus Fagnastesia is introduced to represent low-spired trochoideans with a sculpture of nodes below the suture, angulated whorls, and a wide umbilicus. This Miocene Chilean fauna includes genera that have lived at the coast and in shallow, relatively warm water or deeper, much cooler water. This composition therefore suggests that many of the Miocene formations along the central Chilean coast consist of displaced sediments. A comparison with different fossil and Recent faunas from around the Pacific and South America indicates that the vetigastropod and neritid fauna from the Miocene of Chile has only minor affinities with taxa living near New Zealand, Argentina, and the tropical eastern Pacific at that time.

  6. Biochemical genetic variation in the genus Littorina (Prosobranchia:Mollusca)

    Microsoft Academic Search

    Robert D. Ward

    1990-01-01

    The genus Littorina has been subject to many studies of electrophoretically detectable variation, mostly aimed either at clarifying questions concerned with population structure, or at clarifying difficult taxonomic\\/systematic problems. This paper reviews many of these studies. Topics covered include Hardy-Weinberg deviations, the extent of genetic differentiation among populations within species, founder effects and the effects of human introductions on genetic

  7. Allozyme diversity in slugs of the Carinarion complex (Mollusca, Pulmonata)

    Microsoft Academic Search

    Thierry Backeljau; Luc de Bruyn; Hans de Wolf; Kurt Jordaens; Stefan van Dongen; Birgitta Winnepenninckx

    1997-01-01

    Previous allozyme analyses of the hermaphroditic terrestrial slugs Arion fasciatus, A. circumscriptus and A. silvaticus (subgenus Carinarion) have suggested that in North America these species are each single monomorphic strains. However, new data on 18 putative enzyme loci show that in western Europe the three taxa, respectively, consist of at least three, two and 12 homozygous multilocus genotypes (strains), which

  8. First molecular phylogeny of the subfamily Polycerinae (Mollusca, Nudibranchia, Polyceridae)

    NASA Astrophysics Data System (ADS)

    Palomar, Gemma; Pola, Marta; Garcia-Vazquez, Eva

    2014-03-01

    The subfamily Polycerinae includes four genera with around 46 species described to date. This subfamily is characterized by a limaciform body, which may have simple tentacular processes on the margin of the oral veil. Phylogenetic relationships between the genera of the subfamily Polycerinae (Polyceridae) have not yet been studied, and therefore, the only available information is based on morphological descriptions. The present study reports the first phylogenetic analysis of Polycerinae based on the mitochondrial genes cytochrome oxidase subunit I and the large ribosomal subunit (16S rRNA) using maximum likelihood and Bayesian methods. Our results showed that Polycerinae is monophyletic, but the relationships within the subfamily as well as within Polycera remain unresolved. A key finding of this study is that there are clearly two sympatric species of Polycera present in South Africa: Polycera capensis Quoy and Gaimard, 1824 also found in Australia and an undescribed Polycera sp. On the other hand, the studied specimens of the genus Gymnodoris were clustered within Polycerinae, reopening the problem of the systematic position of this genus. Additional genes and species of Polycerinae and Gymnodoris would provide more information and probably fully resolve this situation.

  9. THE MOLLUSCA OF PORTO RICO. ~ILLIAM HEALEY DALL

    E-print Network

    of the information is scattered through the literature of the West Indies and mollusks in general, from very early confusion. The sea-shell fauna of the West Indies was the source of a large proportion of the shells known later lists, such as those of Beau and Fischer for Guada- ,J.?upe; Krebs and Morch for the 'West Indies

  10. Digestive enzymes of the saltmarsh periwinkle Littorina irrorata (Mollusca: Gastropoda)

    Microsoft Academic Search

    Felix B鋜locher; Thomas L. Arsuffi; Steven Y. Newell

    1989-01-01

    The saltmarsh periwinkleLittorina irrorata is well adapted for the digestion of a wide range of polysaccharides. Enzyme extracts attacked cellulose, pectin, xylan, bean gum and mannan (common in cell walls of higher plants), as well as starch and laminarin (representative of major polysaccharide classes in fungal, algal, and animal tissues). Activities were generally highes at a ph of 5 or

  11. PRINCIPAL DISEASES OF COMMERCIALLY IMPORTANT MARINE BIVALVE MOLLUSCA AND CRUSTACEA

    E-print Network

    and a fatal disease of bivalve larvae in hatcheries. Several species of haplosporidan Protozoa cause serious. Microsporidan Protozoa can be im- As understanding of factors that influence the numbers of animals in the sea

  12. MOLECULAR PHYLOGENY OF COLEOID CEPHALOPODS (MOLLUSCA: CEPHALOPODA) INFERRED FROM THREE

    E-print Network

    McFall-Ngai, Margaret

    (octopuses, squids and cuttlefishes) have produced conflicting results. A wide range of sequence alignment extinct at the end of the Cretaceous, and the Neocoleo- idea, which contains the octopuses, squids

  13. Amundsen Sea Mollusca from the BIOPEARL II expedition.

    PubMed

    Moreau, Camille; Linse, Katrin; Griffiths, Huw; Barnes, David; Kaiser, Stefanie; Glover, Adrian; Sands, Chester; Strugnell, Jan; Enderlein, Peter; Geissler, Paul

    2013-01-01

    Information regarding the molluscs in this dataset is based on the epibenthic sledge (EBS) samples collected during the cruise BIOPEARL II / JR179 RRS James Clark Ross in the austral summer 2008. A total of 35 epibenthic sledge deployments have been performed at five locations in the Amundsen Sea at Pine Island Bay (PIB) and the Amundsen Sea Embayment (ASE) at depths ranging from 476 to 3501m. This presents a unique and important collection for the Antarctic benthic biodiversity assessment as the Amundsen Sea remains one of the least known regions in Antarctica. Indeed the work presented in this dataset is based on the first benthic samples collected with an EBS in the Amundsen Sea. However we assume that the data represented are an underestimation of the real fauna present in the Amundsen Sea. In total 9261 specimens belonging to 6 classes 55 families and 97 morphospecies were collected. The species richness per station varied between 6 and 43. Gastropoda were most species rich 50 species followed by Bivalvia (37), Aplacophora (5), Scaphopoda (3) and one from each of Polyplacophora and Monoplacophora. PMID:23794869

  14. [Chitons (Mollusca: Polyplacophora) from El Salvador, Central America].

    PubMed

    Garc韆-R韔s, Cedar I; Alvarez-Ruiz, Migdalia; Barraza, Jos E; Rivera, Ana M; Hasb鷑, Carlos R

    2007-03-01

    Collections of 11 species of shallow water Polyplacophora from El Salvador were made in July 2002. Previously only five species had been documented in El Salvador: Chaetopleura lurida (Sowerby, 1832); Ischnochiton guatemalensis (Thiele, 1910); Ceratozona angusta (Thiele, 1909); Chiton stokesii (Broderip, 1832) and Acantochitona exquisita (Pilsbry, 1893). Of these, L. guatemalensis and A. exquisita were not collected in this census. Seven other species are reported here for El Salvador for the first time: Lepidochitona beanii (Carpenter, 1857); Ischnochiton dispar (Sowerby, 1832); Stenoplax limaciformis (Sowerby, 1832); Callistochiton expressus (Carpenter, 1865); Acanthochitona arragonites (Carpenter, 1867); A. ferreirai (Lyons, 1988) and A. hirudiniformis (Sowerby, 1832). The known geographic distribution of 1. dispar is extended to the north. An un-named species of Lepidochitona is briefly described. PMID:18457124

  15. Neuronal development in larval chiton Ischnochiton hakodadensis (Mollusca: Polyplacophora).

    PubMed

    Voronezhskaya, Elena E; Tyurin, Sergei A; Nezlin, Leonid P

    2002-02-25

    Chitons are the most primitive molluscs and, thus, a matter of considerable interest for understanding both basic principles of molluscan neurogenesis and phylogeny. The development of the nervous system in trochophores of the chiton Ischnochiton hakodadensis from hatching to metamorphosis is described in detail by using confocal laser scanning microscopy and antibodies raised against serotonin, FMRFamide, and acetylated alpha tubulin. The earliest nervous elements detected were peripheral neurons located in the frontal hemisphere of posthatching trochophores and projecting into the apical organ. Among them, two pairs of unique large lateral cells appear to pioneer the pathways of developing adult nervous system. Chitons possess an apical organ that contains the largest number of neurons among all molluscan larvae investigated so far. Besides, many pretrochal neurons are situated outside the apical organ. The prototroch is not innervated by larval neurons. The first neurons of the developing adult central nervous system (CNS) appear later in the cerebral ganglion and pedal cords. None of the neurons of the larval nervous system are retained in the adult CNS. They cease to express their transmitter content and disintegrate after settlement. Although the adult CNS of chitons resembles that of polychaetes, their general scenario of neuronal development resembles that of advanced molluscs and differs from annelids. Thus, our data demonstrate the conservative pattern of molluscan neurogenesis and suggest independent origin of molluscan and annelid trochophores. PMID:11835180

  16. Die Feinstruktur der 膕theten von Chiton olivaceus (Mollusca, Polyplacophora)

    Microsoft Academic Search

    F. P. Fischer; M. Renner

    1978-01-01

    The aesthete organs in the shell of the polyplacophoranChiton olivaceus (Spengler) were studied by scanning and transmission electron microscopy. Compared to previously described species they reveal marked differences. In the upper third of the aesthete, photoreceptor cells have been found. The granula of the club-shaped cells, which fill most of the aesthete, are formed in the proximal part of young

  17. Amundsen Sea Mollusca from the BIOPEARL II expedition

    PubMed Central

    Moreau, Camille; Linse, Katrin; Griffiths, Huw; Barnes, David; Kaiser, Stefanie; Glover, Adrian; Sands, Chester; Strugnell, Jan; Enderlein, Peter; Geissler, Paul

    2013-01-01

    Abstract Information regarding the molluscs in this dataset is based on the epibenthic sledge (EBS) samples collected during the cruise BIOPEARL II / JR179 RRS James Clark Ross in the austral summer 2008. A total of 35 epibenthic sledge deployments have been performed at five locations in the Amundsen Sea at Pine Island Bay (PIB) and the Amundsen Sea Embayment (ASE) at depths ranging from 476 to 3501m. This presents a unique and important collection for the Antarctic benthic biodiversity assessment as the Amundsen Sea remains one of the least known regions in Antarctica. Indeed the work presented in this dataset is based on the first benthic samples collected with an EBS in the Amundsen Sea. However we assume that the data represented are an underestimation of the real fauna present in the Amundsen Sea. In total 9261 specimens belonging to 6 classes 55 families and 97 morphospecies were collected. The species richness per station varied between 6 and 43. Gastropoda were most species rich 50 species followed by Bivalvia (37), Aplacophora (5), Scaphopoda (3) and one from each of Polyplacophora and Monoplacophora. PMID:23794869

  18. Spawning aggregations and mass movements in subtidal Onchidoris bilamellata (Mollusca

    E-print Network

    Claverie, Thomas

    major prey species, the barnacle Semibalanus balanoides (L., 1767) (Todd, 1979). Spawning occurs between, sudden appearances have also been attributed to colonization by new settlers (Miller, 1961), tidal/current/wave

  19. Climate records from a bivalved Methuselah ( Arctica islandica, Mollusca; Iceland)

    Microsoft Academic Search

    Bernd R. Sch鰊e; Jens Fiebig; Miriam Pfeiffer; Renald Gle?; Jonathan Hickson; Andrew L. A. Johnson; Wolfgang Dreyer; Wolfgang Oschmann

    2005-01-01

    We measured annual shell growth rates of a 374-year-old (radiometrically confirmed) bivalve mollusk specimen of Arctica islandica (Linnaeus). This bivalve represents the oldest ever reported individual animal. In addition, we analyzed 1051 individual powder samples from ontogenetic years two to 40 (=80% of the entire shell height) for isotope analyses. Oxygen and carbon isotopes exhibit clear intra-annual cycles. The highest

  20. Biodiversity and biogeography of Antarctic and sub-Antarctic mollusca

    NASA Astrophysics Data System (ADS)

    Linse, Katrin; Griffiths, Huw J.; Barnes, David K. A.; Clarke, Andrew

    2006-04-01

    For many decades molluscan data have been critical to the establishment of the concept of a global-scale increase in species richness from the poles to the equator. Low polar diversity is key to this latitudinal cline in diversity. Here we investigate richness patterns in the two largest classes of molluscs at both local and regional scales throughout the Southern Ocean. We show that biodiversity is very patchy in the Southern Ocean (at the 1000-km scale) and test the validity of historical biogeographic sub-regions and provinces. We used multivariate analysis of biodiversity patterns at species, genus and family levels to define richness hotspots within the Southern Ocean and transition areas. This process identified the following distinct sub-regions in the Southern Ocean: Antarctic Peninsula, Weddell Sea, East Antarctic桪ronning Maud Land, East Antarctic桬nderby Land, East Antarctic梂ilkes Land, Ross Sea, and the independent Scotia arc and sub Antarctic islands. Patterns of endemism were very different between the bivalves and gastropods. On the basis of distributional ranges and radiation centres of evolutionarily successful families and genera we define three biogeographic provinces in the Southern Ocean: (1) the continental high Antarctic province excluding the Antarctic Peninsula, (2) the Scotia Sea province including the Antarctic Peninsula, and (3) the sub Antarctic province comprising the islands in the vicinity of the Antarctic Circumpolar Current.

  1. How our practice of histopathology, especially tumour pathology has changed in the last two decades: reflections from a major referral center in Pakistan.

    PubMed

    Ahmad, Zubair; Idrees, Romana; Fatima, Saira; Arshad, Huma; Din, Nasir-ud; Memon, Aisha; Minhas, Khurram; Ahmed, Arsalan; Fatima, Syeda Samia; Arif, Muhammad; Ahmed, Rashida; Haroon, Saroona; Pervez, Shahid; Hassan, Sheema; Kayani, Naila

    2014-01-01

    Continued advances in the field of histo-pathology (and cyto-pathology) over the past two decades have resulted in dramatic changes in the manner in which these disciplines are now practiced. This is especially true in the setting of a large university hospital where the role of pathologists as clinicians (diagnosticians), undergraduate and postgraduate educators, and researchers has evolved considerably. The world around us has changed significantly during this period bringing about a considerable change in our lifestyles and the way we live. This is the world of the internet and the world-wide web, the world of Google and Wikipedia, of Youtube and Facebook where anyone can obtain any information one desires at the push of a button. The practice of histo (and cyto) pathology has also evolved in line with these changes. For those practicing this discipline in a poor, developing country these changes have been breathtaking. This is an attempt to document these changes as experienced by histo (and cyto) pathologists practicing in the biggest center for Histopathology in Pakistan, a developing country in South Asia with a large (180 million) and ever growing population. The Section of Histopathology, Department of Pathology and Microbiology at the Aga Khan University Hospital (AKUH) in Karachi, Pakistan's largest city has since its inception in the mid-1980s transformed the way histopathology is practiced in Pakistan by incorporating modern methods and rescuing histopathology in Pakistan from the primitive and outdated groove in which it was stuck for decades. It set histopathology in Pakistan firmly on the path of modernity and change which are essential for better patient management and care through accurate and complete diagnosis and more recently prognostic and predictive information as well. PMID:24935563

  2. New type of protective hybrid and nanocomposite hybrid coatings containing silver and copper with an excellent antibacterial effect especially against MRSA.

    PubMed

    妉amborov, Irena; Zaj韈ov, Veronika; Karp須kov, Jana; Exnar, Petr; Stibor, Ivan

    2013-01-01

    Epidemics spread many types of pathogenic bacterial strains, especially strains of MRSA (Methicillin-resistant Staphylococcus aureus), which are being increasingly reported in many geographical areas [1]. This is becoming to be a serious global problem, particularly in hospitals. Not only are antibiotics proving to be increasingly ineffective but also the bacteria responsible for more than 70% of hospital-acquired bacterial infections are resistant to at least one of the drugs commonly used to treat them. In this study, hybrid coating A1 and nanocomposite hybrid coating A2 based on TMSPM (3-(trimethoxysilyl)propyl methacrylate, MMA (methyl methacrylate), TEOS (tetraethyl orthosilicate) and IPTI (titanium isopropoxide) containing silver and copper ions with or without nanoparticles of titanium dioxide were prepared by the sol-gel method. They were deposited on glass, poly(methyl methacrylate) and cotton using dip-coating or spin-coating, and then cured at 150 癈 for 3 h or, in the case of poly(methyl methacrylate), at 100 癈 for 4.5 h. The morphology and microstructure of these hybrid coatings were examined by SEM. The abrasion resistance was tested using a washability tester and found to depend heavily on the curing temperature. Seven types of bacterial strains were used to determine the profile of antibacterial activity, namely Escherichia coli, Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus - MRSA (CCM 4223), MRSA-2 (CCM 7112), Acinetobacter baumanii, Pseudomonas aeruginosa, and Proteus vulgaris (according to ALE-G18, CSNI). All the samples were tested by irradiating with either a UV-A or a daylight fluorescent lamp. All types of hybrid coating A1 and nanocomposite hybrid coating A2 were found to possess an excellent antibacterial effect, including against the pathogenic bacterial strains of MRSA, which present a dangerous threat on a global scale. PMID:25428071

  3. SISTEMAS TENS蒅RICOS: NUEVAS ALTERNATIVAS PARA LA ROB覶ICA

    Microsoft Academic Search

    Rafael Esteban V醩quez; Julio C閟ar Correa

    2005-01-01

    in this article an introduction to the tensegrity systems is shown. It is also stated some definitions and the notation used for the elements of this kind of structures. The two morphologies more frequently used in the field of robotics and some applications used around the world are described: geodesic domes, tensegrity masts for space applications, tensegrity robot, sensors and

  4. Continuous absence of metaphase-defined cytogenetic abnormalities, especially of chromosome 13 and hypodiploidy, ensures long-term survival in multiple myeloma treated with Total Therapy I: interpretation in the context of global gene expression

    Microsoft Academic Search

    John Shaughnessy; Joth Jacobson; Jeff Sawyer; Jason McCoy; Athanasios Fassas; Fenghuang Zhan; Klaus Bumm; Joshua Epstein; Elias Anaissie; Sundar Jagannath; David Vesole; David Siegel; Raman Desikan; Nikhil Munshi; Ashraf Badros; Erming Tian; Maurizio Zangari; Guido Tricot; John Crowley; Bart Barlogie

    Metaphase cytogenetic abnormalities (CAs), especially of chromosome 13 (CA 13), confer a grave prognosis in multiple myeloma even with tandem autotrans- plantations as applied in Total Therapy I, which enrolled 231 patients between 1989 and 1994. With a median follow-up of almost 9 years, the prognostic implica- tions of all individual CAs, detected prior to treatment and at relapse, were

  5. The University of Calgary has a new system that enhances the safety of faculty and staff when working alone, especially in the evening or outside of normal work hours. The Working Alone system

    E-print Network

    Calgary, University of

    working alone, especially in the evening or outside of normal work hours. The Working Alone system allows. "The Working Alone system is one more way the university is ensuring the safety and security of its provides a preventative means of controlling and reducing the hazards of working alone." Environment

  6. Traditional vaccination is performed by injections, which is painful, causes stress, especially in children and requires trained personnel. Vaccination via the skin provides effective, easy-to-use, painless, and needle-free

    E-print Network

    Hille, Sander

    Traditional vaccination is performed by injections, which is painful, causes stress, especially in children and requires trained personnel. Vaccination via the skin provides effective, easy-to-use, painless, and needle-free vaccination with fewer side effects and safer handling. It has the potential to dramatically

  7. Molecular Phylogenetics and Evolution 36 (2005) 101111 www.elsevier.com/locate/ympev

    E-print Network

    Nishiguchi, Michele

    relationships among squids of the family Gonatidae (Mollusca: Cephalopoda) inferred from three mitochondrial online 1 February 2005 Abstract The oceanic squid family Gonatidae (Mollusca: Cephalopoda) is widely; Brooding; Speciation 1. Introduction Gonatidae (Mollusca: Cephalopoda) is a family of oegopsid oceanic

  8. Gastropoda 753 Beron P. (ed.). Biodiversity of Bulgaria. 3. Biodiversity of

    E-print Network

    Mollov, Ivelin Aldinov

    (Bulgaria and Greece) I. Pensoft & Nat. Mus. Natur. Hist., Sofia Terrestrial gastropods (Mollusca. Terrestrial gastropods (Mollusca: Gastropoda) of the Western Rhodopes (Bulgaria). 颅 In: Beron P. (ed and slugs, Mollusca, Gastropoda, Bulgaria, Western Rhodopes Introduction The physico-geographical region

  9. Date Sunrise/ Tide Time KB

    E-print Network

    Carrington, Emily

    . Wed 0629 1958 1419 (1511) -1.2 Polychaetes Polychaetes Mollusca 12 Apr. Th 0627 2000 1519 (1611) -0.6 Mollusca Gastropods Mollusca 13 Apr. Fr 0625 2001 Last 1623 (1715) 0.2 Apprenticeship Apprenticeship

  10. El teatro cubano en la d閏ada del ochenta: Nuevas propuestas, nuevas promociones

    E-print Network

    Pianca, Marina

    1990-10-01

    llamada dramaturgia de la producci髇, que de un modo sabio nos presenta las situaciones de un colectivo de direcci髇 de un plan industrial y los fraudes productivos que se producen en aras del cumplimiento del plan de producci髇 de dicha unidad.22... teatral latinoamericano, no es hasta 1982 que la revista Tablas se incorpora a la escena cubana como veh韈ulo de discusi髇 y debate en torno a la producci髇 teatral de la isla- veh韈ulo necesario pero inexistente hasta ese momento. No es un producto de...

  11. The Tapir Gallery: Especially for Students

    NSDL National Science Digital Library

    Are you looking for information about tapirs? The Tapir Gallery website (first reported on in the September 15, 1999 Scout Report for Science & Engineering) is as an information resource about tapirs from the Tapir Preservation Fund. This section of the Tapir Gallery site is designed specifically for students searching for information about tapirs for school reports and other such assignments. The site offers basic information about the four species of tapir: Mountain, Malayan, Baird's, and Lowland. The site provides a collection of links to more information about each of these species as well. The website also contains images of tapirs, a list of interesting facts, an extensive bibliography (mostly useful for professionals and older students), and a FAQ section.

  12. African agriculture especially vulnerable to warming climate

    NASA Astrophysics Data System (ADS)

    Wendel, JoAnna

    2014-09-01

    Malnourishment across Africa could jump 40% by 2050 due to climate change, according to the Africa Agriculture Status Report 2014 (AASR), released on 2 September. With temperatures predicted to rise 1.5癈-2.5癈 by midcentury, African smallholder farms, which are generally run by one family, are more vulnerable than ever, the report finds.

  13. [Treatment of especially severe sex offenses].

    PubMed

    Pf鋐flin, F; Haake, E

    1983-05-01

    "Therapy" is a currency with two different notations, as far as court practice is concerned. If the offences are of a minor nature, such as exhibitionism, the judge will usually expect the expert to mention the word, which prompts him to refer the delinquent to a therapist without delay, even if he is not at all hopeful that therapy may be successful. "Therapy" is an inflationary currency. In severe cases, its notation is correspondingly lower. This development has been promoted by the increasing division between forensic and therapeutic perspectives in psychiatry. The difficulties resulting therefore are discussed, taking the example of expertise and therapy of a patient accused of attempted murder as basis. Suggestions are advanced in what manner this division between forensic and therapeutic psychiatry could be avoided or even reduced in future. PMID:6867215

  14. Earth System Models especially those of

    E-print Network

    Shepherd, John

    are we going ? GENIE Model types Conceptual/illustrative to build & test general understanding e.6/5.6 Potsdam (CLIMBER-2) 2.5D at 10 (lat) by 52 (long) Genie 3D at 5 (lat) by 10 (long) #12;CLIMBER-2.Valdes (Genie)P.Valdes (Genie) What is an Earth System Model ?What is an Earth System Model ? #12;Components

  15. The Book Scene...Especially for Teens.

    ERIC Educational Resources Information Center

    Peskorz, Adela, Comp.; And Others

    This annotated bibliography lists approximately 500 titles that reflect the diversity of interests and levels of sophistication among young adult readers between the ages of 12 and 18. Within each subject division is a varied array of fiction and nonfiction titles, some ideal for middle graders, others more appropriate for adult-level readers. The

  16. Cocaine's history, especially the American experience.

    PubMed

    Musto, D F

    1992-01-01

    The history of cocaine in America can be traced to the late 19th century. After the discovery of its physiological and psychological effects, cocaine figured in consumables as diverse as hay fever remedies, local anaesthetics and soft drinks. The development of its different usages as well as eventual control of its use through restrictive legislation followed a different pattern in America from that in Europe. In the United States, national laws to control drugs faced constitutional obstacles until the era of World War I. Initially acclaimed as an ideal tonic, within two decades of its introduction in the mid 1880s cocaine was perceived as an extremely dangerous drug. By the 1930s cocaine had declined in use and in the 1960s, when it gradually emerged again, almost no public memory existed of the earlier 'epidemic'. Once again this substance evolved into a threatening and seductive hazard with some similarities to the earlier episode. PMID:1638922

  17. Russian vaccines against especially dangerous bacterial pathogens

    PubMed Central

    Feodorova, Valentina A; Sayapina, Lidiya V; Corbel, Michael J; Motin, Vladimir L

    2014-01-01

    In response to the epidemiological situation, live attenuated or killed vaccines against anthrax, brucellosis, cholera, glanders, plague and tularemia were developed and used for immunization of at-risk populations in the Former Soviet Union. Certain of these vaccines have been updated and currently they are used on a selective basis, mainly for high risk occupations, in the Russian Federation. Except for anthrax and cholera these vaccines currently are the only licensed products available for protection against the most dangerous bacterial pathogens. Development of improved formulations and new products is ongoing.

  18. UNIVERSIDADE FEDERAL DE SANTA CATARINA CENTRO DE CINCIAS BIOLGICAS

    E-print Network

    Floeter, Sergio Ricardo

    Crustacea e Mollusca. Unidade 4: Organismos planct么nicos: utilizados como alimento na aquacultura, em (Cirripedia), Mollusca, Urochordata (Ascidiacea), Ectoprocta (Bryozoa) e Echinodermata. Unidade 5: Fauna de

  19. DEPARTMENTAL SEMINAR INTEGRATIVE ZOOLOGY Programme Summer Term 2014

    E-print Network

    Pass, G眉nther

    (Mollusca: Bivalvia). Apr 29 : Denise Ivenz: Hoverfly Communities in the NP Ges盲use. May 6: Christina Heindl Ramsmayer: Neurogenesis in Nucula (Mollusca: Bivalvia). Marlene Karelly: Myogenesis in Nucula (Mollusca: Bivalvia). June 24: Anna Pavlicek: Neurogenesis in the invasive zebra mussel Dreissena polymorpha (Mollusca

  20. OIMB GK12 Lesson Kelp Forest Invertebrates

    E-print Network

    : ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ Phylum: Mollusca Mollusks have: ! A chalky, hard shell (usually) ! A single foot Picture

  1. Hermaphroditism among dioecious Tagelus plebeius (Lightfoot, 1786) (Mollusca, Psammobiidae) and Iphigenia brasiliana (Lamarck, 1818) (Mollusca, Donacidae) on the Cachoeira River estuary, Ilh閡s, Bahia, Brazil.

    PubMed

    Ceuta, L O; Boehs, G; Santos, J J B

    2010-02-01

    The samples of Tagelus plebeius and Iphigenia brasiliana were manually collected on the Cachoeira River estuary region (Ilh閡s, BA, Brazil) between August 2005 and August 2006, with a periodicity of 15 days, with 20 animals collected/sampled, performing 500 samples from each species. The animals were measured, eviscerated and kept in solution of Davidson and after 24-30 hours, they were transferred to ethanol 70%. The material was processed for routine histology, with paraffin embedding, obtaining 7 microm thick slices, stained with Harris hematoxilin and Eosin (HE). By light microscopy analysis, 2 cases of hermaphroditism (0.4%) in T. plebeius samples and one case (0.2%) in I. brasiliana were registered with predominance of female over male follicles. PMID:20231968

  2. Seasonal changes in the biochemical composition of the chiton Chiton iatricus (Polyplacophora: Mollusca) and the marine pulmonate Onchidium verruculatum (Gastropoda: Mollusca) in relation to their reproductive cycles

    Microsoft Academic Search

    U. D. Deshpande; R. Nagabhushanam

    1983-01-01

    Seasonal changes in the biochemical composition of two molluses, gonochoric Chiton iatricus and a marine pulmonate, Ochnidium verruculatum inhabiting the same tropical area, but having different modes of reproduction, were studied. Protein is the major biochemical component stored in C. iatricus, whereas lipid is predominantly stored in O. verruculatum. The correlation between these quantifications and the annual reproductive cycles of

  3. In vitro characterization of aggregation and adhesion properties of viable and heat-killed forms of two probiotic Lactobacillus strains and interaction with foodborne zoonotic bacteria, especially Campylobacter jejuni.

    PubMed

    Tareb, Raouf; Bernardeau, Marion; Gueguen, Marielle; Vernoux, Jean-Paul

    2013-04-01

    Bacterial aggregation and/or adhesion are key factors for colonization of the digestive ecosystem and the ability of probiotic strains to exclude pathogens. In the present study, two probiotic strains, Lactobacillus rhamnosus CNCM-I-3698 and Lactobacillus farciminis CNCM-I-3699, were evaluated as viable or heat-killed forms and compared with probiotic reference Lactobacillus strains (Lb. rhamnosus GG and Lb. farciminis CIP 103136). The autoaggregation potential of both forms was higher than that of reference strains and twice that of pathogenic strains. The coaggregation potential of these two beneficial micro-organisms was evaluated against several pathogenic agents that threaten the global safety of the feed/food chain: Escherichia coli, Salmonella spp., Campylobacter spp. and Listeria monocytogenes. The strongest coaggregative interactions were demonstrated with Campylobacter spp. by a coaggregation test, confirmed by electron microscopic examination for the two forms. Viable forms were investigated for the nature of the bacterial cell-surface molecules involved, by sugar reversal tests and chemical and enzymic pretreatments. The results suggest that the coaggregation between both probiotic strains and C. jejuni CIP 70.2(T) is mediated by a carbohydrate-lectin interaction. The autoaggregation potential of the two probiotics decreased upon exposure to proteinase, SDS or LiCl, showing that proteinaceous components on the surface of the two lactobacilli play an important role in this interaction. Adhesion abilities of both Lactobacillus strains were also demonstrated at significant levels on Caco-2 cells, mucin and extracellular matrix material. Both viable and heat-killed forms of the two probiotic lactobacilli inhibited the attachment of C. jejuni CIP 70.2(T) to mucin. In conclusion, in vitro assays showed that Lb. rhamnosus CNCM-I-3698 and Lb. farciminis CNCM-I-3699, as viable or heat-killed forms, are adherent to different intestinal matrix models and are highly aggregative in vitro with pathogens, especially Campylobacter spp., the most commonly reported zoonotic agent in the European Union. This study supports the need for further in vivo investigations to demonstrate the potential food safety benefits of Lb. rhamnosus CNCM-I-3698 and Lb. farciminis CNCM-I-3699, live or heat-killed, in the global feed/food chain. PMID:23329323

  4. Modelos de estados y transicines: nuevas aplicaciones en contexto mundial

    E-print Network

    podemos lograr--transformamos el uso (campo e贸lico!) #12;Un ejemplo: suroeste de EEUU y norte de MexicoReconstrucci贸n hist贸rico Experimentos de manejo GIS Monitoreo #12;35 43B 3 42 133A 8 5 30 136 54 72 58A 40 25 48A 52 73 29

  5. CURSO: ADMINISTRACIN ELECTRNICA. IMPLANTACIN DE LAS NUEVAS TECNOLOGAS EN LA

    E-print Network

    Rey Juan Carlos, Universidad

    ;CAMPUS VIRTUAL CALENDARIO AULA 15 de abril al 14 de Mayo 2013 (9 de mayo de 10h a 12h taller presencial Administraci贸n y Servicios de la URJC Lugar de celebraci贸n: Campus Virtual N煤mero de horas lectivas: 21 horas convocatoria se ruega de los asistentes la debida puntualidad a cada una de las clases. Horario y Aula #12

  6. Nuevas infecciones emergentes: importancia en la salud de los ni駉s

    Microsoft Academic Search

    Jean M. van Seventer; Amanda DeLoureiro; Davidson H. Hamer

    2009-01-01

    ResumenUna interacci髇 compleja entre factores ambientales y humanos, incluyendo factores ecol骻icos, gen閠icos, pol韙icos y socioecon髆icos, es responsable de la emergencia y la resurgencia de enfermedades infecciosas. Estos factores poseen a menudo un efecto claro sobre los ni駉s y, en consecuencia, las infecciones emergentes pueden ejercer impactos 鷑icos sobre las poblaciones m醩 j髒enes en t閞minos de salud f韘ica y mental, as

  7. Nuevas tecnolog韆s, democracia y eficiencia de las instituciones pol韙icas

    Microsoft Academic Search

    Joan Oriol Prats

    2006-01-01

    En este art韈ulo, se estudia el impacto que las tecnolog韆s de la informaci髇 y la comunicaci髇 (TIC) y el nivel de democracia que tienen sobre el desempe駉 de las instituciones pol韙icas. En primer lugar, se estudia emp韗icamente el impacto que las TIC tienen sobre la eficacia de la acci髇 de gobierno. A este respecto, se muestra estad韘ticamente para un conjunto

  8. Neurociencias y publicidad: la nueva frontera de la persuasi髇

    Microsoft Academic Search

    Cristina de Balanz; Joan Sabat

    The new discoveries concerning the working of the human brain which have come from created neuro-scientific research, as well as their strict medical application, have also meant new possibilities for applications in other disciplines, among them econo- mics and marketing. It is already clear that between these disciplines, conceptually very distant in principle, some points of contact have been established

  9. Neuroimagen en la enfermedad de Alzheimer: nuevas perspectivas

    PubMed Central

    Becker, James T.

    2012-01-01

    Introducci髇 y desarrollo En los pr髕imos 50 a駉s vamos a presenciar un incremento significativo de la poblaci髇 mayor de 65 a駉s y por lo tanto va a aumentar, considerablemente, el n鷐ero de individuos con riesgo de desarrollar demencias neurodegenerativas, especialmente la enfermedad de Alzheimer (EA). Las estrategias actuales de tratamiento farmacol骻ico y no farmacol骻ico se han centrado en las fases sintom醫icas de esta enfermedad y, gradualmente, vamos teniendo una mayor comprensi髇 de los posibles factores de riesgo del s韓drome cl韓ico. Conclusiones Los estudios de neuroimagen han sido muy 鷗iles para mostrar los cambios estructurales del envejecimiento normal y patol骻ico, as como tambi閚 los factores de riesgo para la EA. Los tratamientos apropiados de los factores de riesgo y su posible combinaci髇 con tratamientos espec韋icos para la EA podr韆n prolongar el per韔do presintom醫ico de la EA y, por tanto, mejorar la calidad de vida y disminuir la carga para el paciente, la familia y la sociedad. PMID:20517866

  10. BIOLOGA MOLECULAR: LA NUEVA FRONTERA Por EDUARDO CADENAS

    E-print Network

    Escolano, Francisco

    conocimiento natural del que es capaz la mente del hombre" Robert Hooke, MICROGRAPHIA, 1665. "Un aspecto, a investigadores tan destacados como Rudolf Schoenheimer, Linus Pauling, Robert Robinson y George Beadle. Pero el

  11. OBJETIVO GENERAL Los participantes tendrn herramientas para incorporar nuevas estrate-

    E-print Network

    Islas, Le贸n

    Martes 5 de marzo Introducci贸n Aline de la Macorra (2 horas) Jos茅 Urriola (1.5 horas) Martes 12 de marzo Concepto de Infancia y Literatura Anel P茅rez Martes 19 de marzo Tipos de libros LIJ Aline de la Macorra Martes 2 de abril Libro 谩lbum Jos茅 Urriola Martes 9 de abril Libro 谩lbum Aline de la Macorra Martes 16 de

  12. Nuevas investigaciones en la ense馻nza de los idiomas

    Microsoft Academic Search

    Peter Jan Slagter

    1992-01-01

    No puedo empezar esta conferencia sin darles las gr acias a los organizadores de este encuentro por su hospitalidad y a los participantes por su gran franqueza a la hora de intercambiar experiencias, opiniones y frustracione s. En esta conferencia intentar echar un puente entre investigaciones que se hacen all por esos mundos y lo que he visto durante estos

  13. Hacia la Nueva Reforma (Toward the New Reform).

    ERIC Educational Resources Information Center

    Ribeiro, Darcy

    A new wave of reform is needed for Latin American universities suffering from structural rigidity, duplicity, inefficiency, and lack of community. The structural crisis in the university reflects the general social crisis in which society is pressured by opposing forces leading it toward either historical modernization or evolutionary

  14. La penetraci髇 del web corporativo y del comercio electr髇ico en las empresas de servicios y comercio de la ciudad de Lleida

    Microsoft Academic Search

    Jordi Mill Rufach

    2007-01-01

    Las nuevas tecnolog韆s de la informaci髇 y de la comunicaci髇 y en especial el sitio web corporativo y el comercio electr髇ico suponen una nueva oportunidad de difusi髇 de imagen y de negocio para las empresas y comercios en una econom韆 cada vez m醩 global. Dentro de este marco te髍ico general, la ciudad de Lleida se sit鷄 en una posici髇 relativamente

  15. The land Mollusca of Dominica (Lesser Antilles), with notes on some enigmatic or rare species

    Microsoft Academic Search

    D. G. Robinson; A. Hovestadt; A. Fields; A. S. H. Breure

    2009-01-01

    An overview of the land-snail fauna of the Lesser Antillean island of Dominica is given, based on data from literature and four recent surveys. There are 42 taxa listed, of which the following species are recorded for the first time from the island: Allopeas gracile (Hutt on, 1834), A. micra (d扥rbigny, 1835), Beckianum beckianum (L. Pfeiffer, 1846), Bulimulus diaphanus fraterculus

  16. Notes on land slugs : 11. Arionidae, Milacidae and Limacidae from South Africa (Mollusca, Gastropoda Pulmonata)

    Microsoft Academic Search

    Regteren Altena van C. O

    1966-01-01

    New records of Arion intermedius Norm. are given. All known data on the genus Oopelta M鰎ch have been compiled and supplemented by new observations, mainly on O. nigropunctata M鰎ch and O. capensis Poll. Of the former species the type specimens were examined and the external variation and anatomy were studied. A fine series of O. capensis, with notes on the

  17. The Continuing Debate on Deep Molluscan Phylogeny: Evidence for Serialia (Mollusca, Monoplacophora + Polyplacophora)

    PubMed Central

    St鰃er, I.; Sigwart, J. D.; Kano, Y.; Knebelsberger, T.; Marshall, B. A.; Schwabe, E.; Schr鰀l, M.

    2013-01-01

    Molluscs are a diverse animal phylum with a formidable fossil record. Although there is little doubt about the monophyly of the eight extant classes, relationships between these groups are controversial. We analysed a comprehensive multilocus molecular data set for molluscs, the first to include multiple species from all classes, including five monoplacophorans in both extant families. Our analyses of five markers resolve two major clades: the first includes gastropods and bivalves sister to Serialia (monoplacophorans and chitons), and the second comprises scaphopods sister to aplacophorans and cephalopods. Traditional groupings such as Testaria, Aculifera, and Conchifera are rejected by our data with significant Approximately Unbiased (AU) test values. A new molecular clock indicates that molluscs had a terminal Precambrian origin with rapid divergence of all eight extant classes in the Cambrian. The recovery of Serialia as a derived, Late Cambrian clade is potentially in line with the stratigraphic chronology of morphologically heterogeneous early mollusc fossils. Serialia is in conflict with traditional molluscan classifications and recent phylogenomic data. Yet our hypothesis, as others from molecular data, implies frequent molluscan shell and body transformations by heterochronic shifts in development and multiple convergent adaptations, leading to the variable shells and body plans in extant lineages. PMID:24350268

  18. Organization pattern of nacre in Pteriidae (Bivalvia: Mollusca) explained by crystal competition

    PubMed Central

    Checa, Antonio G; Okamoto, Takashi; Ram韗ez, Joaqu韓

    2006-01-01

    Bivalve nacre is a brick-wall-patterned biocomposite of aragonite platelets surrounded by organic matter. SEM杄lectron back scatter diffraction analysis of nacre of the bivalve family Pteriidae reveals that early aragonite crystals grow with their c-axes oriented perpendicular to the growth surface but have their a- and b-axes disoriented. With the accumulation of successive lamellae, crystals progressively orient themselves with their b-axes mutually parallel and towards the growth direction. We propose that progressive orientation is a result of competition between nacre crystals at the growth front of lamellae, which favours selection of crystals whose fastest growth axis (b-axis) is oriented parallel to the direction of propagation of the lamella. A theoretical model has been developed, which simulates competition of rhombic plates at the lamellar growth front as well as epitaxial growth of crystals onto those of the preceding lamella. The model predicts that disordered nacre progressively produces bivalve-like oriented nacre. As growth fronts become diffuse (as is the common case in bivalves) it takes longer for nacre to become organized. Formation of microdomains of nacre platelets with different orientations is also reproduced. In conclusion, not only the organic matrix component, but also the mineral phase plays an active role in organizing the final microstructure. PMID:16777720

  19. Unusual micrometric calcite-aragonite interface in the abalone shell Haliotis (Mollusca, Gastropoda).

    PubMed

    Dauphin, Yannicke; Cuif, Jean-Pierre; Castillo-Michel, Hiram; Chevallard, Corinne; Farre, Bastien; Meibom, Anders

    2014-02-01

    Species of Haliotis (abalone) show high variety in structure and mineralogy of the shell. One of the European species (Haliotis tuberculata) in particular has an unusual shell structure in which calcite and aragonite coexist at a microscale with small patches of aragonite embedded in larger calcitic zones. A detailed examination of the boundary between calcite and aragonite using analytical microscopies shows that the organic contents of calcite and aragonite differ. Moreover, changes in the chemical composition of the two minerals seem to be gradual and define a micrometric zone of transition between the two main layers. A similar transition zone has been observed between the layers in more classical and regularly structured mollusk shells. The imbrication of microscopic patches of aragonite within a calcitic zone suggests the occurrence of very fast physiological changes in these taxa. PMID:24188740

  20. [Occurrence of Achatina fulica Bowdich, 1822 (Mollusca, Gastropoda) in Brazil: intermediate snail host of angiostrongyliasis].

    PubMed

    Teles, H M; Vaz, J F; Fontes, L R; Domingos, M de F

    1997-06-01

    Achatina fulica, the intermediate snail host of angiostrongyliasis and also an agricultural pest, is being bred in Brazil for human consumption as "escargot". The snail has escaped from its artificial breeding sites and its dispersal in Itariri country, State of S. Paulo, is reported here for the first time. A. fulica is a transmitter of the rat lungworm Angiostrongylus cantonensis, nematode which causes meningoencephalic angiostrongyliasis; the risks of human contamination are commented on. PMID:9515269

  1. Molecular Evolution and Phylogeny of Actin Genes in Haliotis Species (Mollusca: Gastropoda)

    Microsoft Academic Search

    Frank Y. T. Sin; Maxine J. Bryant; Alice Johnstone

    2007-01-01

    codon usage bias was evident in the actin gene family of these 4 haliotids. Phylogenetic analysis of the actin gene family revealed 2 distinct clades with H. iris actins A1, A1a, A1b, and A1c, H. virginea A1, A2, and A3, and H. rufescens actin in 1 clade and H. discus actin and H. iris actins A2 and A3 in the

  2. Genetics and shell morphometrics of assimineids (Mollusca, Caenogastropoda, Truncatelloidea) in the St Lucia Estuary, South Africa

    PubMed Central

    Miranda, Nelson A. F.; van Rooyen, Ryan; MacDonald, Angus; Ponder, Winston; Perissinotto, Renzo

    2014-01-01

    Abstract The Assimineidae are a family of amphibious microgastropods that can be mostly found in estuaries and mangroves in South Africa. These snails often occur in great numbers and are ecologically important to the St Lucia Estuary, which forms a crucial part of the iSimangaliso Wetland Park, a UNESCO World Heritage Site. Genetic and shell morphometric analyses were conducted on individuals collected from nine localities distributed from the northern lake regions to the southern lake and the mouth of the St Lucia estuarine lake. Mitochondrial (COI) and nuclear (28S) DNA was used to construct Bayesian Inference, Neighbour-joining, Maximum Parsimony and Maximum Likelihood trees. Principal Component Analysis and Cluster Analysis were performed on standard shell parameter data. Results indicate that two different taxa are present in St Lucia. The taxon comprising individuals from the South Lake and St Lucia Estuary Mouth is identified as Assiminea cf. capensis Bartsch, in accordance with the latest taxonomic consensus. The taxon comprising assimineid individuals from False Bay, North Lake and South Lake, is here tentatively named 揂ssiminea aff. capensis (Sowerby). These two taxa exhibit patterns of spatial overlap that appear to vary depending on environmental parameters, particularly salinity. The need to resolve the complex taxonomy of assimineids is highlighted. PMID:25061361

  3. Morphological and molecular evidence for cryptic species of springsnails [genus Pseudamnicola ( Corrosella) (Mollusca, Caenogastropoda, Hydrobiidae)

    PubMed Central

    Delicado, Diana; Ramos, Marian A.

    2012-01-01

    Abstract Several Pseudamnicola (Corrosella) populations of the central and eastern Iberian Peninsula have been ascribed to Pseudamnicola (Corrosella) astieri (Dupuy, 1851), though recent evidence demonstrates the species could be endemic to the departments of Var and Alpes-Maritimes in France. Through the identification of cryptic species using a combined morphological and phylogenetic approach, this paper provides a detailed morphological description of Pseudamnicola (Corrosella) astieri, clarifying its taxonomic boundaries and confirming it as a French endemic. In parallel, by comparing Pseudamnicola (Corrosella) populations from the provinces of Castell髇 and Valencia in Eastern Spain, it was observed that rather than Pseudamnicola (Corrosella) astieri they represented a new species here described as Pseudamnicola (Corrosella) hauffei sp. n. Among other characters, the two species show marked differences in shell shape, male and female genital systems, radular formula and concentration of the nervous system. Pseudamnicola (Corrosella) hauffei sp. n. was also compared morphologically to another two Pseudamnicola (Corrosella) species living in nearby areas [Pseudamnicola (Corrosella) hinzi Boeters, 1986 and Pseudamnicola (Corrosella) navasiana (Fagot, 1907)], molecularly to Pseudamnicola (Corrosella) falkneri (Boeters, 1970), the type species of the subgenus, and to the rest of the Pseudamnicola (Corrosella) species described so far. Morphological differentiation between the species is supported by a genetic divergence of 7.4% inferred from a partial sequence (658 bp) of the mitochondrial gene cytochrome c oxidase subunit I (COI). On the basis of an average 8% (5.39 to 11.15%) divergence estimated for the COI gene in other Pseudamnicola (Corrosella) species reported in GenBank, the existence of two specific entities is here proposed, which will have impact on conservation policies both in France and in Spain. PMID:22639531

  4. Investigation of the Origin of Insular Races of Land Mollusca in the Scilly Isles

    Microsoft Academic Search

    G. C. Robson; O. W. Richards

    1925-01-01

    THE study of insular species of animals has for a long time been regarded as an important adjunct to evolutionary research, and the r鬺e of insular segregation as a factor in specific divergence has been stressed by numerous workers. It has of later years been held that one of the best ways of studying the effects of such isolation is

  5. Mechanisms and functional morphology associated with metal transport in Mercenaria mercenaria (Bivalvia:Mollusca)

    SciTech Connect

    Robinson, W.E.; Morse, M.P.

    1984-02-20

    Studies on the morphological and physiological effects of environmental pollutants on both adult and larval marine bivalve molluscs are described. We have established a substantial data base on metals accumulation within individual organs of the quahog, Mercenaria mercenaria. In addition, studies on the transport, detoxification and elimination of cadmium and silver in this important species are reported. We have shown that various components of marine oilwell drilling muds can have deleterious effects on both adult sea scallops, Placopecten magellanicus, and surf clams, Spisula solidissima. For example, both Q-broxin and attapulgite clay, at concentrations as low as 100 mg 1/sup -1/, effected both the integrity of the sea scallop pseudolamellibranch gill and the rate of gill frontal ciliary activity.

  6. Characterization of a highly repeated DNA family in tapetinae species (mollusca bivalvia: veneridae).

    PubMed

    Passamonti, M; Mantovani, B; Scali, V

    1998-08-01

    A repetitive DNA family (phBglII400) was characterized in the clam species Tapes philippinarum (Veneridae Tapetinae). The tandemly repeated sequences are AT-rich and show a mainly pericentromeric localization, as most satellite DNAs do. Sequence analysis of phBglII400 DNA family showed a high level of intraspecific homogeneity. Furthermore a 200 bp subunit motif within the 400 bp monomer was apparent as well as the existence of two main "open reading frames" along the 400 bp sequence.In order to investigate the possible distribution of this DNA family among Veneridae, Southern blot analyses were performed on genomic DNAs of Tapes decussatus, Venerupis aurea and Paphia undulata (Tapetinae), Callista chione (Pitarinae), Chamelea gallina (Chioninae) and Venus verrucosa (Venerinae). The phBglII400 family has been found in two additional Tapetinae, namely V. aurea and P. undulata, but not in T. decussatus or other analyzed species. This pattern of sat-DNA distribution supports the high level of differentiation of T. decussatus observed in the previous gene-allozyme analysis. All of these suggest a better allocation of T. decussatus to a genus different from that of T. philippinarum. PMID:18462043

  7. Nucularcidae: A new family of palaeotaxodont Ordovician pelecypods (Mollusca) from North America and Australia

    USGS Publications Warehouse

    Pojeta, J., Jr.; Stott, C.A.

    2007-01-01

    The new Ordovician palaeotaxodont family Nucularcidae and the new genus Nucularca are described. Included in Nucularca are four previously described species that have taxodont dentition: N. cingulata (Ulrich) (the type species), N. pectunculoides (Hall), N. lorrainensis (Foerste), and N. gorensis (Foerste). All four species are of Late Ordovician (Cincinnatian; Katian) age and occur in eastern Canada and the northeastern USA. Ctenodonta borealis Foerste is regarded as a subjective synonym of Nucularca lorrainensis. No new species names are proposed. The Nucularcidae includes the genera Nucularca and Sthenodonta Pojeta and Gilbert-Tomlinson (1977). Sthenodonta occurs in central Australia in rocks of Middle Ordovician (Darriwilian) age. The 12 family group names previously proposed for Ordovician palaeotaxodonts having taxodont dentition are reviewed and evaluated in the Appendix. ?? 2007 NRC Canada.

  8. Biodiversity among luminescent symbionts from squid of the genera Uroteuthis, Loliolus and Euprymna (Mollusca: Cephalopoda)

    E-print Network

    Ruby, Edward G.

    of species of luminescent bacteria that have not been previously described as symbiotic strains colonizing Luminescent bacteria in the family Vibrionaceae (Bacteria: c-Proteobacteria) are commonly found in complex families of squid is similar, the species of bacteria that inhabit each host has yet to be verified. We

  9. A combined approach to the phylogeny of Cephalopoda (Mollusca) A. R. Lindgren1,

    E-print Network

    Nishiguchi, Michele

    to deep benthic waters. While cephalopods remain at the forefront of modern biology, in providing insight characters to test the relationships of 60 species of cephalopods, with emphasis within Decabrachia (squids depths. Cephalopods exhibit many unique characteristics that distinguish them from other molluscs

  10. Novel polymorphic microsatellite markers isolated from the pen shell Atrina pectinata (Mollusca: Bivalvia: Pinnidae).

    PubMed

    Wu, B; Bai, L J; Yang, A G; Zhou, L Q; Liu, Z H

    2014-01-01

    In this study, we isolated 21 novel polymorphic microsatellite DNA loci from the pen shell Atrina pectinata using magnetic-bead hybridization enrichment. The characteristics of these loci were tested using a population of 30 individuals collected from the Penglai coast, Shandong Province. The number of alleles ranged from 2 to 13, and polymorphism information content (PIC) varied from 0.1730 to 0.8954. Values for observed heterozygosity (HO) and expected heterozygosity (HE) ranged from 0.0714 to 0.9231 and from 0.1948 to 0.9237, respectively. Four loci deviated significantly from Hardy-Weinberg equilibrium. The newly developed microsatellite markers will be beneficial in assessing the genetic diversity, population structure and genetic conservation of A. pectinata, and in other relevant research. PMID:25526185

  11. Body condition and gametogenic cycle of Galatea paradoxa (Mollusca: Bivalvia) in the Volta River estuary, Ghana

    NASA Astrophysics Data System (ADS)

    Adjei-Boateng, D.; Wilson, J. G.

    2013-11-01

    The reproductive cycle of Galatea paradoxa which is the basis for an artisanal fishery in the Volta River estuary, Ghana, was studied using condition indices and histological methods from March 2008 to July 2009. The cycle is annual with a single spawning event between June and October. Gametogenesis starts in November progressing steadily to a peak in June-July when spawning begins until October when the animal is spent. The condition indices (shell-free wet weight/total wet weight, ash-free dry weight/shell weight and gonad wet weight/shell weight) showed a clear relationship with the gametogenic stage rising from a minimum at stage (I) start of gametogenesis, to their highest values at stages (IIIA) ripe and (IIIB) start of spawning before declining significantly to stage (IV) spent.It is suggested that condition index may prove a valuable technique in fishery management to recognise the reproductive stages of G. paradoxa as it is less expensive and time consuming than histological techniques in addition to being easier to teach to non-specialists. The data presented in this study provide information on the timing of spawning events for G. paradoxa, which is necessary for developing sustainable management strategies and selection of broodstock for aquaculture.

  12. Food intake and growth in reared early juvenile cuttlefish Sepia officinalis L. (Mollusca Cephalopoda)

    Microsoft Academic Search

    N. Koueta; E. Boucaud-Camou

    1999-01-01

    Experimental rearing of juvenile cuttlefish was carried out in a semi-closed system for 40 days at 19癈. Different quantities of live food were offered to isolated animals. The actual ingestion rate was enhanced by the amount of food offered, this tendency decreasing with age. Frozen food was ingested at the same rate, but was less effective than live food for

  13. Basic growth relations in experimental rearing of early juvenile cuttlefish Sepia officinalis L. (Mollusca: Cephalopoda)

    Microsoft Academic Search

    N Koueta; E Boucaud-Camou

    2001-01-01

    Basic growth relations were studied in experimental rearing of juvenile cuttlefish during 40 days. Eleven different rations of food were offered in order to establish the maintenance, optimum, and maximum rations during the early life of these animals. The maintenance ration, 23.5% of body weight, decreased with age. The optimum rations were, respectively, 16.2%, 14% and 9% during 10, 20

  14. Allozyme differentiation in the cuttlefish Sepia officinalis (Mollusca: Cephalopoda) from the NE Atlantic and Mediterranean

    Microsoft Academic Search

    Marcos P閞ez-Losada; 羘gel Guerra; Andr閟 Sanjuan

    1999-01-01

    The Atlantic朚editerranean area has recently been proposed as a new phylogeographical area on the basis of concordance of genetic differentiation patterns observed in several marine species. However, additional taxa need to be studied to establish the phylogeographical relationship between the Atlantic and Mediterranean. Eleven samples of the cuttlefish Sepia officinalis around the Iberian Peninsula, one from the Canary Islands, and

  15. Absence of social recognition in laboratory-reared cuttlefish, Sepia officinalis L. (Mollusca: Cephalopoda)

    Microsoft Academic Search

    JEAN GEARY BOAL

    1996-01-01

    Five experiments were performed to determine the level of social recognition in captive-reared adult cuttlefish,Sepia officinalisL. No evidence of discrimination of familiar from unfamiliar individuals was found in either females or males. Despite good evidence for mate guarding, no recognition of individual mates was found. Within sex classes, associations between freely moving animals were not different from random (f杅, f杕

  16. The complete mitochondrial genome of the giant African snail Achatina fulica (Mollusca: Achatinidae).

    PubMed

    Yang, Huirong; Zhang, Jia-En; Guo, Jing; Deng, Zhixin; Luo, Hao; Luo, Mingzhu; Zhao, Benliang

    2014-09-18

    Abstract We present the complete mitochondrial genome of the Achatina fulica in this study. The results show that the mitochondrial genome is 15,057?bp in length, which is comprised of 13 protein-coding genes, 2 rRNA genes, 21 tRNA genes. The nucleotide compositions of the light strand are 35.47% of A, 27.97% of T 19.46% of C, and 17.10% of G. Except the ND3, 7 tRNA, ATP6, ATP8, COX3 and 12S-rRNA on the light strand, the rest are encoded on the heavy strand. Five types of inferred initiation codons are ATA (ND1, ND5), GTG (ND6), ATG (COX3, COX2), ATT (ND4) and TTG (COX1, ND2, ND3, ND4L, ATP6, ATP8, Cytb), and 3 types of inferred termination codons are T (COX3, ND2), TAA (ND1, ND4L, ND5, ND6, ATP6), and TAG (ND3, ND4, COX1, COX2, Cytb, ATP8). There are 24 intergenic spacers and 6 gene overlaps. The tandem repeat sequence (total 52?bp) of (AATAATT)n is observed in 16S-rRNA. Gene arrangement and distribution are inconsistent with the typical vertebrates. PMID:25231719

  17. The mitochondrial genome of the sipunculid Phascolopsis gouldii supports its association with Annelida rather than Mollusca

    Microsoft Academic Search

    Jeffrey L. Boore; Joseph L. Staton

    2001-01-01

    We have determined the sequence of about half (7470 nts) of the mitochondrial genome of the sipunculid Phascolopsis gouldii, the first representative of this phylum to be so studied. All of the 19 identified genes are transcribed from the same DNA strand. The arrangement of these genes is remarkably similar to that of the oligochaete annelid Lumbricus terrestris. Comparison of

  18. Three new species of Pruvotinidae (Mollusca: Solenogastres) from Antarctica and NW Spain

    NASA Astrophysics Data System (ADS)

    Zamarro, Maria; Garc韆-羖varez, Oscar; Urgorri, Victoriano

    2013-09-01

    The family Pruvotinidae (Solenogastres, Cavibelonia) includes thirty species of fifteen genera grouped in five subfamilies. These subfamilies are defined by the combination of the presence or absence of hollow hook-shaped sclerites, the presence or absence of a dorsopharyngeal gland and the type of ventrolateral foregut glandular organs: type A, type C or circumpharyngeal. In this paper, three new species of the family Pruvotinidae are described: Pruvotina artabra n. sp. and Gephyroherpia impar n. sp. from NW Spain, and Pruvotina manifesta n. sp. from Antarctic Peninsula. These new descriptions increase the global knowledge of Solenogastres biodiversity.

  19. Random walk, zonation and the food searching strategy of Terebralia palustris (Mollusca, Potamididae) in Kenya

    NASA Astrophysics Data System (ADS)

    Vannini, Marco; Cannicci, Stefano; Mrabu, Elisha; Rorandelli, Rocco; Fratini, Sara

    2008-12-01

    Terebralia palustris is a common mud-whelk present at a particularly high density in all Indo-West Pacific mangroves. Young snails feed on nothing but mud while larger specimens are able to feed on fallen leaves too. In Kenya (Mida Creek) under the canopy, competition for mangrove leaves can be very high due to the high density of Sesarmidae crabs. On open exposed muddy platforms, no Sesarmidae occur but the leaf density is very low because the leaves are only randomly present as they are deposited and removed twice a day by the tide. However, the snail density is always very high, raising the question as to whether the snails use a special searching strategy to optimize their resource finding rather than a purely random movement. By analyzing the snails' movements on a uniform area at different levels and comparing them with simulated random paths, we could show that the snails' movements are not purely random. The distribution of different size classes of T. palustris in Mida Creek was known to be quite odd: the same simulation approach suggests that the zonation asymmetry could reasonably be due to the stochastic recruitment of juveniles in space and time and maintained by a substantial long-lasting spatial inertia.

  20. Phylogeny and evolution of ontogeny of the family Oxytomidae Ichikawa, 1958 (Mollusca: Bivalvia)

    NASA Astrophysics Data System (ADS)

    Lutikov, O. A.; Temkin, I. E.; Shurygin, B. N.

    2010-08-01

    We described ontogenies and reconstructed morphogeneses of hinges in some supraspecific taxa of the bivalve family Oxytomidae Ichikawa, 1958 from the Mesozoic of Russia. The phylogeny of the family is reconstructed using evolutionary and cladistic methods. The appearance of the endemic genus Arctotis Bodylevsky, 1960 in the epicontinental seas of Siberia can be explained in terms of gradual transformations of the ligament and byssal apparatus in the Northern Siberian members of Praemeleagrinella Lutikov et Shurygin, 2009 and Praearctotis Lutikov et Shurygin, 2009.

  1. Analysis of enzymes in the Bulinus africanus group (Mollusca: Planorbidae) by isoelectric focusing

    Microsoft Academic Search

    C. A. Wright; D. Rollinson

    1979-01-01

    Four enzyme systems have been analysed in digestive gland extracts of snails of the Bulinus africanus group. Forty population samples, representing eight of the ten nominal species recognized in the group, have been examined. Three distinct enzyme types were recognized in each of three of the systems and ten types in the fourth. Few of the individual enzyme types show

  2. Spermatozoa and spermatogenesis in the northern quahaug Mercenaria mercenaria (Mollusca, Bivalvia)

    NASA Astrophysics Data System (ADS)

    Ying, Xue-Ping; Yang, Wan-Xi; Dahms, Hans-U.; Lin, Zhihua; Chai, Xueliang

    2008-12-01

    We studied the ultrastructure of spermatogenesis and spermatozoa in the northern quahaug, the clam Mercenaria mercenaria. Spermatogenetic cells gradually elongate. Mitochondria gradually fuse and increase in size and electron density. During spermatid differentiation, proacrosomal vesicles migrate towards the presumptive anterior pole of the nucleus and eventually form the acrosome. The spermatozoon of M. mercenaria is of a primitive type. It is composed of head, mid-piece, and tail. The acrosome shows a subacrosomal space with a short conical contour. The slightly curved nucleus of the spermatozoon contains fine-grained dense chromatin. The middle piece consists of a centriolar complex which is surrounded by four mitochondria. The flagellum has a standard 9 + 2 microtubular structure. The ultrastructure of spermatozoa and spermatogenesis of M. mercenaria shares a number of features with other species of the family Veneridae. M. mercenaria may be a suitable model species for further investigations into the mechanisms of spermatogenesis in the Bivalvia.

  3. The Fine Morphology of the Osphradial Sense Organs of the Mollusca. I. Gastropoda, Prosobranchia

    Microsoft Academic Search

    G. Haszprunar

    1985-01-01

    The comparative ultrastructure of osphradia is investigated in 51 species of prosobranch gastropods, representative of nearly all superfamilies as well as of various habits and environments. The essential results show that the sensory epithelium of the osphradium as a whole may reflect environmental conditions, whereas the ultrastructure of osphradial cell types reflects actual taxonomic relations. Accordingly, the following taxa can

  4. Recovery of the biogenic nest habitat of Limaria hians (Mollusca: Limacea) following anthropogenic disturbance

    NASA Astrophysics Data System (ADS)

    Trigg, Colin; Moore, Colin G.

    2009-04-01

    The rate of regrowth of Limaria hians nest material, following a simulated dredging impact, was examined on an extensive L. hians bed off the west coast of Scotland. Within an area of complete coverage of the sea bed by a turf of L. hians nest material, the turf was cleared by diver from 10 0.25 m 2 plots and the sediment subsequently raked to simulate the passage of a scallop dredge. The areal extent and pattern of nest regrowth were recorded after 6 and 12 months. Control plots showed no significant change in 100% nest cover over the year. In the treated plots regrowth generally occurred from extension of peripheral nest material. Over the initial 6 autumn and winter months treatment plots displayed a mean regrowth of 9.2% of the cleared area, increasing to 15% in the second 6-month spring and summer period. However, no significant difference in growth was found between these periods. After 12 months half the treatment plots exhibited <25% nest cover and none of them contained nest of a thickness comparable to the surrounding bed. Conversion of regrowth rates within the treated plots to the rate of nest advance along a linear front, gave a value of 3.2 cm per year, highlighting the susceptibility of this species-rich biotope to scallop dredging.

  5. Vestigial phragmocone in the gladius points to a deepwater origin of squid (Mollusca: Cephalopoda)

    NASA Astrophysics Data System (ADS)

    Arkhipkin, Alexander I.; Bizikov, Vyacheslav A.; Fuchs, Dirk

    2012-03-01

    The microstructure of the gladius cone was investigated in six species of nektonic squid: shallow-water Loligo gahi (Loliginidae), pelagic eurybathic Illex argentinus, Todarodes pacificus, Dosidicus gigas (Ommastrephidae), and deepwater Onykia ingens (Onychoteuthidae) and Gonatus antarcticus (Gonatidae) using state-of-the-art microscopy. Apart from L. gahi, all other species had septa-like layers in the gladius cone, which for the first time were investigated in detail and compared with those in extinct Cretaceous belemnites Hibolithes sp. and Pachyteuthis sp., and spirulid Cyrtobelus sp. It was found that the organic layers of the gladius cone in recent squid can be homologized with the organic components of the shell in fossil phragmocone-bearing coleoids. The septa-like layers in modern gladius cones therefore represent a vestigial phragmocone composed of organic septal rudiments of the ancestral phragmocone that has lost the siphuncle and gas-filled chambers. The well-developed rostrum in onychoteuthids and small rostrum of the gladius in ommastrephids and gonatids can be seen as homologous with the belemnoid rostrum, which may indicate a close phylogenetic relationship between belemnites and at least some squid. Possible evolutionary pathways of the reduction of the functional phragmocone in squid ancestors are discussed. Several features such as the loss of shell calcification, deep water speciation, and the structure of the equilibrium organ point to a deep-water origin of squids.

  6. An ultrastructural examination of developing and mature euspermatozoa in pyrazus ebeninus (Mollusca, Gastropoda, Potamididae)

    Microsoft Academic Search

    J. M. Healy

    1982-01-01

    Mature and developing euspermatozoa of the prosobranch gastropod Pyrazus ebeninus, have been examined using transmission electron microscopy and phase-contrast light microscopy. The head of the mature euspermatozoon consists of a conical acrosome capping a short, rod-shaped nucleus (laterally compressed posteriorly). A basal invagination in the nucleus contains the proximal portion of the axoneme and a dense attachment matrix. Four apparently

  7. Evaluation of Freshwater Mussel (Mollusca: Unionoidea) Fitness Pre- and Post- Relocation Efforts

    NASA Astrophysics Data System (ADS)

    McIntyre, H. E.; Farris, J. L.; Christian, A. D.

    2005-05-01

    Freshwater mussels are often displaced by human activities. Construction of bridges that offer potential impact to large numbers mussels often results in a relocation strategy to minimize loss. While this may reduce mortality, the metabolic consequences of relocation have not been evaluated. In this study we measured glycogen and lipid concentrations and RNA to DNA ratios to determine fitness impairments on relocated mussels. We hypothesize that organisms subjected to continuous stress should first use stored glycogen, followed by growth cessation measured as a reduction of RNA in relation to the DNA present, and finally a mobilization of tissue lipids, measured as a decrease in tissue lipid concentrations. We collected mantle snips from three surrogate species of mussels from four sites on the White River in eastern Arkansas during late summer, to establish expected glycogen, lipid, and RNA:DNA levels. Mean tissue lipids concentrations (?g/g) were 63.09, 67.96, and 50.46 for Quadrula quadrula, Q. pustulosa and Obliquaria reflexa, respectively. Mean tissue glycogen concentrations (?g/g) were 346.66, 592.26, and 336.58 for Q. quadrula, Q. pustulosa, and O. reflexa, respectively. This study can provide response information on relocated individuals as well as provide estimation of sufficient time required for mussel adaptation to novel environments.

  8. Annual internal growth banding and life history of the ocean quahog Arctica islandica (Mollusca: Bivalvia)

    Microsoft Academic Search

    I. Thompson; D. S. Jones; D. Dreibelbis

    1980-01-01

    Internal growth bands visible in cross-sections of the valves and hinge plates of Arctica islandica Linn are deposited annually, possibly in response to the reproductive cycle. Growth rate and longevity, inferred from the bands, are surprising: A. islandica grows very slowly and lives to an advanced age. Individuals with more than 90 bands are not uncommon; the maximum number of

  9. Experimental evidence for limited dispersal of haliotid larvae (genus Haliotis; Mollusca: Gastropoda)

    Microsoft Academic Search

    J D Prince; T. L. Sellers; W. B. Ford; S. R. Talbot

    1987-01-01

    The literature on haliotids generally assumes that these organisms have a short pelagic larval life with dispersal powers limited only by the time available before settlement. The results of an experiment designed to test this assumption are presented. The density of mature Haliotti rubra Leach was experi- mentally decreased along a 90 m section of shoreline. The resulting effect on

  10. Ultrastructure of euspermatozoa and paraspermatozoa in the volutid snail Adelomelon ancilla (Mollusca: Caenogastropoda)

    NASA Astrophysics Data System (ADS)

    Zabala, S.; Hermida, G. N.; Gim閚ez, J.

    2009-09-01

    The ultrastructure of the euspermatozoa and the paraspermatozoa is investigated in Adelomelon ancilla, through histological section observed by transmission electron microscopy. Euspermatozoa of A. ancilla consists of: (1) a conical acrosomal vesicle (with a short basal invagination, constricted anteriorly) which is flattened at the apex and associated with an axial rod, a centrally perforated basal plate and a short accessory membrane, (2) a rod-shaped, solid and highly electron-dense nucleus (with a short basal fossa containing a centriolar complex and a initial portion of a 9 + 2 axoneme), (3) an elongate midpiece consisting of the axoneme sheathed by 5-6 helical mitochondrial elements each exhibiting a dense U-shaped outer layer, (4) an elongate glycogen piece (where the axoneme is sheathed by nine tracts of glycogen granules), (5) a dense annulus at the junction of the midpiece and glycogen piece, and (6) a short free tail region (where the axoneme is surrounded only by plasma membrane). We observed a parasperm in A. ancilla. This is vermiform in shape and is composed of multiple axonemes and extensive cytoplasm with numerous vesicles, and mitochondria are scattered inside the axonemes. Sperm of A. ancilla is characterized by the euspermatozoa type 2 and the paraspermatozoa morphology belongs to type 5. The U shaped electrodense mitochondrial element in the midpiece of the eusperm and the constriction in the acrosomal vesicle present in A. ancilla are exclusive. We suggest that these characteristics could have taxonomic importance, because these was observed in other volutids and have not been observed in the rest of caenogastropods studies. We consider that the morphology of paraspermatozoa in A. ancilla corresponds to the 搇ancet type.

  11. Genetic Variation in a Gradient of Environmental Variability: Marine Bivalvia (Mollusca)

    Microsoft Academic Search

    Jeffrey Levinton

    1973-01-01

    Six bivalve mollusk species were sampled for genetic variability at two enzyme synthesizing loci. The effective number of alleles and absolute number of alleles decreased with depth of burial within the sediment, intertidally, and with depth of water, subtidally. It is proposed that environmental variability regulates genetic variability at these two loci.

  12. Phylogeny and Historical Biogeography of the Loliginid Squids (Mollusca: Cephalopoda) Based on Mitochondrial DNA Sequence Data

    Microsoft Academic Search

    Frank E. Anderson

    2000-01-01

    The cephalopod taxon Loliginidae (Cephalopoda: Myopsida) is a species-rich group of tropical and temperate shallow-water squids, many of which are commercial fisheries objects and neurophysiological research organisms. The worldwide distribution of these squids could make Loliginidae a useful case study in shallow-water marine biogeography, but the phylogeny of the group is unknown. To clarify loliginid phylogeny, regions of two mitochondrial

  13. Gill function and particle transport in Placopecten magellanicus (Mollusca: Bivalvia) as revealed using video endoscopy

    Microsoft Academic Search

    Peter G. Beninger; J. Evan Ward; Bruce A. MacDonald; Raymond J. Thompson

    1992-01-01

    The technique of endoscopic video observation was used to study feeding processes of Placopecten magellanicus (Gmelin), collected from Bull Arm, Newfoundland in August 1991 and 1992, under near-natural feeding conditions. The fate of captured particles depended on the extent of ingestive or handling capacity saturation. Under low (1 to 10 particles 祃-1) to medium (10 to 20 particles 祃-1) particle

  14. Rich and rare桭irst insights into species diversity and abundance of Antarctic abyssal Gastropoda (Mollusca)

    NASA Astrophysics Data System (ADS)

    Schwabe, Enrico; Michael Bohn, Jens; Engl, Winfried; Linse, Katrin; Schr鰀l, Michael

    2007-08-01

    The abyssal depths of the polar oceans are thought to be low in diversity compared with the shallower polar shelves and temperate and tropical deep-sea basins. Our recent study on the gastropod fauna of the deep Southern Ocean gives evidence of the existence of a rich gastropod assemblage at abyssal depths. During the ANDEEP I and II expeditions to the southern Drake Passage, Northwestern Weddell Sea, and South Sandwich Trench, gastropods were collected by bottom and Agassiz trawls, epibenthic sledge, and multicorer, at 40 stations in depths between 127 and 5194 m. On the whole, 473 specimens, corresponding to 93 species of 36 families, were obtained. Of those, 414 specimens were caught below 750 m depth and refer to 84 (90%) benthic species of 32 (89%) families. Most families were represented by a single species only. The numerically dominant families were Skeneidae and Buccinidae (with 10 and 11 species, respectively), Eulimidae and Trochidae (with 9 species each), and Turridae (6 species). Thirty-Seven benthic deep-sea species (44%) were represented by a single specimen, and another 20 species (24%) were found at a single station, suggesting that more than two thirds of Antarctic deep-sea gastropod species are very rare or have a very scattered distribution. Of the 27 species occurring at two or more deep-sea stations, 14 were collected with different gear. Approximately half of the deep-water species are new to science or have been recently described. The present investigation increases the total number of recorded benthic Antarctic deep-sea gastropods (below 750 m) from 115 to 177. The previously known depth ranges have been extended, often considerably, for 31 species. The collected deep-sea gastropods comprise both eurybathic shelf species (29%) and apparently true deep-sea species (58%); some of the latter may belong to a so far unknown Antarctic abyssal fauna. Geographical ranges of the collected Antarctic benthic deep-sea gastropod species appear limited, and all these 84 species seem endemic to Antarctica south of the Polar Front. Comparing diversity and abundances based on epibenthic sledge samples, there is no clear relationship between Antarctic deep-sea gastropod abundance and species richness with depth. However, both Antarctic and adjacent deep-sea areas are still far from being adequately sampled to allow more comprehensive conclusions.

  15. Evolution and systematics in Haliotidae (Mollusca: Gastropoda): inferences from DNA sequences of sperm lysin

    Microsoft Academic Search

    Youn-Ho Lee; V. D. Vacquier

    1995-01-01

    Abalone taxonomy and systematics have remained unresolved: neither stable species-level nomenclature nor a cladistic hypothesis of relationships among species have been established. To infer the phylogeny of the genus Haliotis and to identify species using molecular data, we compared complementary DNA (cDNA) sequences of sperm lysin from 27 species-group taxa from California, Japan, Australia, New Zealand, Taiwan, Borneo, Madagascar, South

  16. Spawning, fertilization, and larval development of Potamocorbula amurensis (Mollusca: Bivalvia) from San Francisco Bay, California

    USGS Publications Warehouse

    Nicolini, M.H.; Penry, D.L.

    2000-01-01

    In Potamocorbula amurensis time for development to the straight-hinge larval stage is 48 hr at 15??C. Potamocorbula amurensis settles at a shell length of approximately 135 ??m 17 to 19 days after fertilization. Our observations of timing of larval devdlopment in P. amurensis support the hypothesis of earlier workers that its route of initial introduction to San Francisco Bay was as veliger larvae transported in ballast water by trans-Pacific cargo ships. The length of the larval period of P. amurensis relative to water mass residence times in San Francisco Bay suggests that it is sufficient to allow substantial dispersal from North Bay to South Bay populations in concordance with previous observations that genetic differentiation among populations of P. amurensis in San Francisco Bay is low. Potamocorbula amurensis is markedly euryhaline at all stages of development. Spawning and fertilization can occur at salinities from 5 to 25 psu, and eggs and sperms can each tolerance at least a 10-psu step increase or decrease in salinity. Embryos that are 2 hr old can tolerate the same range of salinities from (10 to 30 psu), and by the time they are 24 hr old they can tolerate the same range of salinities (2 to 30 psu) that adult clams can. The ability of P. amurensis larvae to tolerate substantial step changes in salinity suggests a strong potential to survive incomplete oceanic exchanges of ballast water and subsequent discharge into receiving waters across a broad range of salinities.

  17. An ultrastructural examination of developing and mature paraspermatozoa in Pyrazus ebeninus (Mollusca, Gastropoda, Potamididae)

    Microsoft Academic Search

    J. M. Healy; B. G. M. Jamieson

    1981-01-01

    The mesogastropod Pyrazus ebeninus, produces true spermatozoa (here termed euspermatozoa) and multi-flagellate, mobile cells (here termed paraspermatozoa). The mature paraspermatozoon consists of an elongateconical 慼ead (6.58.5 祄 in length), constructed of an electron-dense mosaic sheath surrounding a similarly dense, rod-shaped nuclear core (which runs almost the full length of the head). An acrosome-like structure forms the apex of the head.

  18. Sources of Energy for Increased Metabolic Demand During Metamorphosis of the Abalone Haliotis rufescens (Mollusca)

    Microsoft Academic Search

    FRASER M. SHILLING; OVE HOEGH-GULDBERG; DONAL T. MANAHAN

    Pelagic, lecithotrophic (nonfeeding) larvae of the red abalone (Haliotis rzdfescens) settle and subse- quently metamorphose into benthic juveniles capable of feeding on particulate food. Thus, metamorphosis must be fueled by either endogenous reserves or a nonparticu- late food source such as dissolved organic material (DOM) in seawater. The metabolic rates (measured as oxygen consumption) of abalone larvae were found to

  19. Development and metamorphosis of the planktotrophic larvae of Rostanga pulchra (Mollusca: Nudibranchia)

    Microsoft Academic Search

    F. S. Chia; R. Koss

    1978-01-01

    Rostanga pulchra MacFarland, a small (1 to 2 cm) dorid nudibranch, lays an average of 7000 eggs in the laboratory during a period of 30 days in the summer. The veligers hatch 15 to 16 days after oviposition and it takes another 35 to 40 days to become competent for metamorphosis at a temperature of 10 to 15癈. Larval cultures

  20. Freshwater bivalve mollusca (unionidae, sphaeriidae, corbiculidae) of the Savannah River Plant, South Carolina

    SciTech Connect

    Britton, J.C.; Fuller, S.L.H.

    1980-11-01

    A guide to freshwater bivalve molluscs found at the Savannah River Plant is presented. A dichotomous taxonomic key is provided to common forms and to unreported species whose geographic distributions include nearby localities. Discussions of ecology, life history, larval hosts, and other pertinent information is provided. (ACR)

  1. Preliminary study on the culture and breeding of Bulinus nyassanus (Mollusca: Pulmonata) under

    E-print Network

    Boyer, Elizabeth W.

    on the feasibility of using facultative snail-eating fishes as biological control agents for intermediate hosts haematobium. The laboratory culture of this snail species is essential in relation to further experiments, the snail feeds on detritus within the sediment, and under laboratory conditions it will not feed on either

  2. Biomphalaria straminea (Mollusca: Planorbidae) as an intermediate host of Ribeiroia sp. (Trematoda: Psilostomidae) in Brazil.

    PubMed

    Pinto, H A; Jadin, R C; Orlofske, S A; Johnson, P T J; Melo, A L

    2013-10-01

    Species of Ribeiroia are trematode parasites of birds and mammals that have acquired notoriety since Ribeiroia ondatrae was identified as a cause of mortality and malformations in North American amphibians. Although species of Ribeiroia have been reported in vertebrate hosts in South America, the snails involved in its transmission remain unknown in Brazil. During malacological studies conducted at Pampulha Reservoir, Belo Horizonte, Minas Gerais, Brazil, between January 2009 and February 2012, in total 14,264 specimens of Biomphalaria straminea were collected, of which 192 (1.35%) were infected with gymnocephalous cercariae. The larvae were used for experimental infection of laboratory-reared guppies ( Poecilia reticulata ); metacercariae obtained in these fishes were orally administered to domestic ducks (Cairina moschata); and adult parasites were obtained from the proventriculus 10 days after infection. Based on morphological and molecular analyses, the parasite was identified as Ribeiroia sp., a species morphologically similar to R. ondatrae , but distinctly different at the molecular level. This is the first report of larvae of Ribeiroia in Brazil and B. straminea as a new intermediate host for this genus. PMID:23421393

  3. Mercury and the estuarine clam, Rangia cuneata (Mollusca - Bivalvia): uptake and release, survival and osmoregulation

    E-print Network

    Dillon, T. M

    1976-01-01

    - sicator. Anal sis of Inor anic Ions Sodium and potassium were analyzed with a Perkin-Elmer atomic ab- sorption spectrophotometer Model 403. Whole clams were digested in 10 ml conc. nitric acid, diluted 1000X in cation-free water and acidified with 100...

  4. New records for the shallow-water chiton fauna (Mollusca, Polyplacophora) of the Azores (NE Atlantic)

    PubMed Central

    羦ila, S閞gio P.; Sigwart, Julia

    2013-01-01

    Abstract Published records, original data from recent field work on all of the islands of the Azores (NE Atlantic), and a revision of the entire mollusc collection deposited in the Department of Biology of the University of the Azores (DBUA) were used to compile a checklist of the shallow-water Polyplacophora of the Azores. Lepidochitona cf. canariensis and Tonicella rubra are reported for the first time for this archipelago, increasing the recorded Azorean fauna to seven species. PMID:23825446

  5. Mechanisms underlying dual effects of serotonin during development of Helisoma trivolvis (Mollusca)

    PubMed Central

    2014-01-01

    Background Serotonin (5-HT) is well known as widely distributed modulator of developmental processes in both vertebrates and invertebrates. It is also the earliest neurotransmitter to appear during neuronal development. In aquatic invertebrates, which have larvae in their life cycle, 5-HT is involved in regulation of stages transition including larval metamorphosis and settlement. However, molecular and cellular mechanisms underlying developmental transition in aquatic invertebrate species are yet poorly understood. Earlier we demonstrated that in larvae of freshwater molluscs and marine polychaetes, endogenous 5-HT released from the neurons of the apical sensory organ (ASO) in response to external stimuli retarded larval development at premetamorphic stages, and accelerated it at metamorphic stages. Here we used a freshwater snail Helisoma trivolvis to study molecular mechanisms underlying these dual developmental effects of 5-HT. Results Larval development of H. trivolvis includes transition from premetamorphic to metamorphic stages and shares the main features of metamorphosis with free-swimming aquatic larvae. Three types of 5-HT receptors (5-HT1-, 5-HT4- and 5-HT7-like) are functionally active at premetamorphic (trochophore, veliger) and metamorphic (veliconcha) stages, and expression patterns of these receptors and respective G proteins undergo coordinated changes during development. Stimulation of these receptors modulated cAMP-dependent regulation of cell divisions. Expression of 5-HT4- and 5-HT7-like receptors and their downstream Gs protein was down-regulated during the transition of pre- to metamorphic stage, while expression of 5-HT1 -like receptor and its downstream Gi protein was upregulated. In accordance with relative amount of these receptors, stimulation of 5-HTRs at premetamorphic stages induces developmental retardation, while their stimulation at metamorphic stages induces developmental acceleration. Conclusions We present a novel molecular mechanism that underlies stage-specific changes in developmental tempo of H. trivolvis larvae in response to endogenous 5-HT produced by the neurons of the ASO. We suggest that consecutive changes in expression patterns of different receptors and their downstream partners in the course of larval development represent the molecular base of larval transition from premetamorphic (non-competent) to metamorphic (competent) state. PMID:24625099

  6. COMPARISON OF FOUR DNA EXTRACTION METHODS FROM INVASIVE FRESHWATER BIVALVE SPECIES (MOLLUSCA: BIVALVIA) IN ROMANIAN FAUNA

    Microsoft Academic Search

    OANA PAULA POPA; DUMITRU MURARIU; LUIS OVIDIU POPA

    2007-01-01

    In this paper we propose an evaluation of four DNA extraction methods in terms of DNA quantity, quality and success of the subsequent PCR amplifications of nuclear and mitochondrial loci. Individuals from the following freshwater invasive mussels in Romania were used to asses the efficiency of the DNA extraction methods: Dreissena polymorpha, Dreissena bugensis, Sinanodonta woodiana and Corbicula fluminea. While

  7. Induction of larval settlement and metamorphosis of Haliotis discus hannai Ino (Gastropoda, Mollusca)

    NASA Astrophysics Data System (ADS)

    Yang, Yu; Wu, Bao-Ling

    1995-03-01

    Conspecific foot mucus, excessive [K+] and gamma-aminobutyric acid (GABA) showed different metamorphosis-inductive effect on the veliger of Haliotis discus hannai. The inductive effect of excessive [K+] and GABA was developmental stage-dependent and dose-dependent, while that of conspecific foot mucus was only developmental stage-dependent. At 20癈 the veliger larvae became competent within 4 days after fertilization. H. discus hannai larvae showed gregarious settlement pattern on the conspecific foot mucus under the conditions of either presence or absence of KCl or GABA. The present studies showed that the effect of conspecific foot mucus on abalone larvae metamorphosis could be dose-independent.

  8. Submarine canyons as the preferred habitat for wood-boring species of Xylophaga (Mollusca, Bivalvia)

    NASA Astrophysics Data System (ADS)

    Romano, C.; Voight, J. R.; Company, J. B.; Plyuscheva, M.; Martin, D.

    2013-11-01

    Submarine canyons are often viewed as natural 揹ebris concentrators on the seafloor. Organic substrates may be more abundant inside than outside canyon walls. To determine the effects of the presence these substrates in the Blanes submarine canyon (NW Mediterranean) and its adjacent western open slope, we deployed wood to study colonizing organisms. Three replicate pine and oak cubes (i.e. most common trees inland) were moored at 900, 1200, 1500 and 1800 m depth and collected after 3, 9 and 12 months. Wood from inside the canyon was significantly more heavily colonized by the five morphotypes of wood-boring bivalves than was wood on the adjacent open slope. Xylophaga sp. A dominated all wood types and locations, with peak abundance at 900 and 1200 m depth. Its growth rate was highest (0.070 mm d-1) during the first three months and was faster (or it recruits earlier) in pine than in oak. Size distribution showed that several recruitment events may have occurred from summer to winter. Xylophaga sp. B, appeared first after 9 months and clearly preferred pine over oak. As the immersion time was the same, this strongly supported a specific association between recruiters and type of substrate. Three morphotypes, pooled as Xylophaga spp. C, were rare and seemed to colonize preferentially oak inside the canyon and pine in the adjacent open slope. Individuals of Xylophaga were more abundant inside the canyon than in nearby off-canyon locations. Blanes Canyon may serve as a long-term concentrator of land-derived vegetal fragments and as a consequence sustain more animals. Are the species richness and abundance of wood-boring bivalves higher inside the canyon than on the adjacent open slope? Do the composition and density of the wood-boring bivalves change with deployment time and depth, as well as on the type of the sunken wood? What is the growth rate of the dominant wood-boring species?

  9. European Lymnaeidae (Mollusca: Gastropoda), intermediate hosts of trematodiases, based on nuclear ribosomal DNA ITS2 sequences

    Microsoft Academic Search

    M. D Bargues; M Vigo; P Horak; J Dvorak; R. A Patzner; J. P Pointier; M Jackiewicz; C Meier-Brook; S Mas-Coma

    2001-01-01

    Freshwater snails of the family Lymnaeidae are of a great parasitological importance because of the very numerous helminth species they transmit, mainly trematodiases of large medical and veterinary impact. The present knowledge on the genetics of lymnaeids and on their parasite杊ost inter-relationships is far from being sufficient. The family is immersed in a systematic杢axonomic confusion. The necessity for a tool

  10. European Lymnaeidae (Mollusca: Gastropoda), intermediate hosts of trematodiases, based on nuclear ribosomal DNA ITS-2 sequences.

    PubMed

    Bargues, M D; Vigo, M; Horak, P; Dvorak, J; Patzner, R A; Pointier, J P; Jackiewicz, M; Meier-Brook, C; Mas-Coma, S

    2001-12-01

    Freshwater snails of the family Lymnaeidae are of a great parasitological importance because of the very numerous helminth species they transmit, mainly trematodiases of large medical and veterinary impact. The present knowledge on the genetics of lymnaeids and on their parasite-host inter-relationships is far from being sufficient. The family is immersed in a systematic-taxonomic confusion. The necessity for a tool which enables species distinction and population characterization is evident. This paper aims to review the European Lymnaeidae basing on the second internal transcribed spacer ITS-2 of the nuclear ribosomal DNA. The ITS-2 sequences of 66 populations of 13 European and 1 North American lymnaeid species, including the five generic (or subgeneric) taxa Lymnaea sensu stricto, Stagnicola, Omphiscola, Radix and Galba, have been obtained. The ITS-2 proves to be a useful marker for resolving supraspecific, specific and population relationships in Lymnaeidae. Three different groupings according to their ITS-2 length could be distinguished: Radix and Galba may be considered the oldest taxa (370-406 bp lengths), and Lymnaea s. str., European Stagnicola and Omphiscola (468-491 bp lengths) the most recent, American Stagnicola and Hinkleyia being intermediate (434-450 bp lengths). This hypothesis agrees with the phylogeny of lymnaeids based on palaeontological data, chromosome numbers and radular dentition. ITS-2 sequences present a conserved central region flanked by two variable lateral regions corresponding to the 5' and 3' ends. The number of repeats of two microsatellites found in this conserved central region allows to differentiate Radix from all other lymnaeids. Phylogenetic trees showed four clades: (A) Lymnaea s. str., European Stagnicola and Omphiscola; (B) Radix species; (C) Galba truncatula; and (D) North American stagnicolines. ITS-2 results suggest that retaining Stagnicola as a subgenus of Lymnaea may be the most appropriate and that genus status for Omphiscola is justified. Radix shows a complexity suggesting different evolutionary lines, whereas G. truncatula appears to be very homogeneous. North American and European stagnicolines do not belong to the same supraspecific taxon; the genus Hinkleyia may be used for the American stagnicolines. Genetic distances and sequence differences allowed us to distinguish the upper limit to be expected within a single species and to how different sister species may be. S. palustris, S. fuscus and S. corvus proved to be valid species, but S. turricula may not be considered a species independent from S. palustris. Marked nucleotide divergences and genetic distances detected between different S. fuscus populations may be interpreted as a process of geographic differentiation developping in the present. Among Radix, six valid species could be distinguished: R. auricularia, R. ampla, R. peregra (=R. ovata;=R. balthica), R. labiata, R. lagotis and Radix sp. The information which the ITS-2 marker furnishes is of applied interest concerning the molluscan host specificity of the different trematode species. The phylogenetic trees inferred from the ITS-2 sequences are able to differentiate between lymnaeids transmitting and those non-transmitting fasciolids, as well as between those transmitting F. hepatica and those transmitting F. gigantica. The Fasciola specificity is linked to the two oldest genera which moreover cluster together in the phylogenetic trees, suggesting an origin of the Fasciola ancestors related to the origin of this branch. European Trichobilharzia species causing human dermatitis are transmitted only by lymnaeids of the Radix and Lymnaea s. str.-Stagnicola groups. Results suggest the convenience of reinvestigating compatibility differences after accurate lymnaeid species classification by ITS-2 sequencing. Similarly, ITS-2 sequencing would allow a step forward in the appropriate rearrangement of the actual systematic confusion among echinostomatids. PMID:12798024

  11. The complete mitochondrial genome of Solemya velum (Mollusca: Bivalvia) and its relationships with Conchifera

    PubMed Central

    2013-01-01

    Background Bivalve mitochondrial genomes exhibit a wide array of uncommon features, like extensive gene rearrangements, large sizes, and unusual ways of inheritance. Species pertaining to the order Solemyida (subclass Opponobranchia) show many peculiar evolutionary adaptations, f.i. extensive symbiosis with chemoautotrophic bacteria. Despite Opponobranchia are central in bivalve phylogeny, being considered the sister group of all Autobranchia, a complete mitochondrial genome has not been sequenced yet. Results In this paper, we characterized the complete mitochondrial genome of the Atlantic awning clam Solemya velum: A-T content, gene arrangement and other features are more similar to putative ancestral mollusks than to other bivalves. Two supranumerary open reading frames are present in a large, otherwise unassigned, region, while the origin of replication could be located in a region upstream to the cox3 gene. Conclusions We show that S. velum mitogenome retains most of the ancestral conchiferan features, which is unusual among bivalve mollusks, and we discuss main peculiarities of this first example of an organellar genome coming from the subclass Opponobranchia. Mitochondrial genomes of Solemya (for bivalves) and Haliotis (for gastropods) seem to retain the original condition of mollusks, as most probably exemplified by Katharina. PMID:23777315

  12. External morphology of spermatozoa and spermatozeugmata of the freshwater mussel Truncilla truncata (Mollusca: Bivalvia: Unionidae)

    USGS Publications Warehouse

    Waller, D.L.; Lasee, B.A.

    1997-01-01

    Truncilla truncata males release spherical aggregates of spermatozoa, called spermatozeugmata, at spawning. Sperm aggregates from other bivalve species have been described, but few detailed studies exist of the morphology of unionid spermatozeugmata and spermatozoa. We provide the first description of the external morphology of spermatozeugmata and spermatozoa of T. Truncata. The spermatozeugmata had an inside diameter of 76 mu m and contained 8000-9000 spermatozoa. Heads of spermatozoa were directed toward the center of the sphere into a translucent shell; tails were arranged radially and caused the spermatozeugmata to rotate. Spermatozoa of T. Truncata measured 3.3 mu m in length (excluding tail) and each had a head, a midpiece and a flagellum. We also documented the release of spermatozeugmata in two additional unionid species, Lampsilis cardium and Amblema plicata plicata.

  13. A study of the distribution of estuarine mollusca in eastern Saint Bernard Parish, Louisiana

    E-print Network

    Jones, John Arthur

    1960-01-01

    , not Described in Abbott (1954) IWtt gall ~+AC!NS ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 94 ~co ~toh Ql t i ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 95 Q+mQBS ~ktltUS ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 96 Snail C ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 96 LISI' (F TARL&S l... species of cephalopcd in the study area. Gf these, only three specL s of pelecypods~ 5hQBL HMULQX Qi3HHQfhZOR Xki&LR "nd ~ 2$5LL species of gastropod& the unidentified planktonic snail, w re common to all three complexes, Two additional species...

  14. Patterns of Diversity of the Rissoidae (Mollusca: Gastropoda) in the Atlantic and the Mediterranean Region

    PubMed Central

    羦ila, S閞gio P.; Goud, Jeroen; de Frias Martins, Ant髇io M.

    2012-01-01

    The geographical distribution of the Rissoidae in the Atlantic Ocean and Mediterranean Sea was compiled and is up-to-date until July 2011. All species were classified according to their mode of larval development (planktotrophic and nonplanktotrophic), and bathymetrical zonation (shallow species梩hose living between the intertidal and 50?m depth, and deep species梩hose usually living below 50?m depth). 542 species of Rissoidae are presently reported to the Atlantic Ocean and the Mediterranean Sea, belonging to 33 genera. The Mediterranean Sea is the most diverse site, followed by Canary Islands, Caribbean, Portugal, and Cape Verde. The Mediterranean and Cape Verde Islands are the sites with higher numbers of endemic species, with predominance of Alvania spp. in the first site, and of Alvania and Schwartziella at Cape Verde. In spite of the large number of rissoids at Madeira archipelago, a large number of species are shared with Canaries, Selvagens, and the Azores, thus only about 8% are endemic to the Madeira archipelago. Most of the 542-rissoid species that live in the Atlantic and in the Mediterranean are shallow species (323), 110 are considered as deep species, and 23 species are reported in both shallow and deep waters. There is a predominance of nonplanktotrophs in islands, seamounts, and at high and medium latitudes. This pattern is particularly evident in the genera Crisilla, Manzonia, Onoba, Porosalvania, Schwartziella, and Setia. Planktotrophic species are more abundant in the eastern Atlantic and in the Mediterranean Sea. The results of the analysis of the probable directions of faunal flows support the patterns found by both the Parsimony Analysis of Endemicity and the geographical distribution. Four main source areas for rissoids emerge: Mediterranean, Caribbean, Canaries/Madeira archipelagos, and the Cape Verde archipelago. We must stress the high percentage of endemics that occurs in the isolated islands of Saint Helena, Tristan da Cunha, Cape Verde archipelago and also the Azores, thus reinforcing the legislative protective actions that the local governments have implemented in these islands during the recent years. PMID:22693430

  15. Marine Mollusca from Expedition Fiord, Western Axel Heiberg Island, Northwest Territories, Canada

    Microsoft Academic Search

    ALEC E. AITKEN; ROBERT GILBERT

    1996-01-01

    Marine molluscs, including bivalves, gastropods and scaphopods, were recovered by dredging at depths of 3 - 82 m in Expedition Fiord, Axel Heiberg Island, Canada. Cluster analysis, based on presence\\/absence data at 27 stations, defined two mollusc associations within the fiord. A Portlandia-Thyasira association, characterized by the abundance of Portlandia arctica and Thyasira gouldi, inhabits silty clay substrates at depths

  16. Lethal and Sub-lethal Effects of UVB on Juvenile Biomphalaria glabrata (Mollusca: Pulmonata)

    PubMed Central

    Ruelas, Debbie S.; Karentz, Deneb; Sullivan, John T.

    2007-01-01

    Although Schistosoma mansoni occurs mainly in the tropics, where intense levels of solar radiation are present, the impact of ultraviolet (UV) light on schistosome transmission is not known. The purpose of this study was to investigate potential effects of UVB (290320 nm) on juvenile Biomphalaria glabrata, the snail intermediate host of S. mansoni. Albino and wild type snails were exposed to doses of UVB from UV-fluorescent lamps, and the following were measured: survival, photoreactivation (light-mediated DNA repair), effects on feeding behavior, and morphological tissue abnormalities. Irradiation with UVB is lethal to B. glabrata in a dose-dependent manner. Exposure to white light subsequent to UVB irradiation enhances survival, probably by photoreactivation. The shell offers some, but not complete, protection. Experiments in which UVB transmittance through the shell was blocked with black nail polish suggest that injury to both exposed (headfoot) and shell-enclosed (mantle and visceral mass) tissues contributes to mortality in lethally-irradiated snails. Wild-type (pigmented) snails are less susceptible to lethal effects of UVB than albino snails, and they may be more capable of photoreactivation. UVB exposure inhibits snail feeding behavior, and causes tentacle forks and growths on the headfoot. Thus, UVB may influence the life cycle of S. mansoni by both lethal and sub-lethal damage to the snail intermediate host. However, the ability of snails to photoreactivate may mitigate these effects. PMID:16996081

  17. The types, publication date, and validity of Nucella elongata Golikov & Kussakin (Mollusca, Ocenebrinae).

    PubMed

    Chichvarkhin, Anton; Chichvarkhina, Olga

    2014-01-01

    The name Nucella heyseana var. elongata Golikov & Kussakin, 1962 was proposed for a 'form of uncertain taxonomic level', found in Kunashir and Sakhalin islands. However, this entity was previously recorded as Thais lamellosa (non Gmelin, 1791) (Kussakin 1956: 105-106, 108). In this description, the individual collected from southern shore of Kunashir Island was verbally described in the text and illustrated with a photographic image (Golikov & Kussakin 1962: 312-315, pl. 2, fig. 2c ['?' in Russian]). N. heyseana var. elongata was expressly proposed as an infrasubspecific entity, as a variation of N.爃eyseana (Dunker, 1882) specific to particular habitats. Therefore it is not an available name according the provisions of International Code of Zoological Nomenclature Articles 45.5 and 45.6.3 (ICZN 1999; hereafter the Code). According to Article 1.3.4 it should be excluded from the species group as not regulated by the Code. In 1974, Golikov & Kussakin described this form as the species Nucella elongata Golikov and Kussakin, 1962, mentioning the same entity (Golikov & Kussakin 1974: 295). This verbal description is identical with their previous text published in 1962, although the new species was not illustrated. However, the same specimen from Kunashir Island was clearly designated as the holotype repeating the same shell measurements and collecting location. In this and following publications N.爀longata was reported from Kurile Islands and Sakhalin (Golikov & Kussakin 1978: 190-191, fig. 132; Golikov & Scarlato 1985: 426). In 1978, they repeated their texts dated 1962 and 1974 confirming the same specimen from Kunashir Island as the holotype preserved in Zoological Institute, Russian Academy of Sciences, St. Petersburg (ZIN) collection, although they illustrated different shell (presumably a paratype, which we did not find in ZIN) obtained from southeastern Sakhalin. PMID:25544462

  18. Taxonomy and paleobiology of some Middle Cambrian Scenella (Cnidaria) and Hyolithids (Mollusca) from western North America

    E-print Network

    Babcock, Loren E.; Robison, Richard A.

    1988-12-29

    (lower left); KUMIP 204343, x 2. 2. Helen showing tapering in both prox- imal (left) and distal (right) directions; coated with MgO; small articulate brachiopod near posterior edge of helen, probably a fortuitous association; KUMIP 204352, X4. 6... (lower left); KUMIP 204343, x 2. 2. Helen showing tapering in both prox- imal (left) and distal (right) directions; coated with MgO; small articulate brachiopod near posterior edge of helen, probably a fortuitous association; KUMIP 204352, X4. 6...

  19. Occurrence of Conchophthirus acuminatus (Protista: Ciliophora) in Dreissena polymorpha (Mollusca: Bivalvia) along the River Shannon, Ireland

    Microsoft Academic Search

    David Bruce Conn; Sarah E. Simpson; Dan Minchin; Frances E. Lucy

    2008-01-01

    Samples of Dreissena polymorpha were collected at several sites along the River Shannon navigation in Ireland, to determine the occurrence and distribution\\u000a of their obligate host-specific commensalistic ciliate, Conchophthirus acuminatus, in this newly invaded region. Mussels collected by various methods were fixed immediately in 75% ethanol, in which they\\u000a were later dissected under a stereoscopic microscope, beginning with thorough flushing

  20. From sea to land and beyond New insights into the evolution of euthyneuran Gastropoda (Mollusca)

    PubMed Central

    2008-01-01

    Background The Euthyneura are considered to be the most successful and diverse group of Gastropoda. Phylogenetically, they are riven with controversy. Previous morphology-based phylogenetic studies have been greatly hampered by rampant parallelism in morphological characters or by incomplete taxon sampling. Based on sequences of nuclear 18S rRNA and 28S rRNA as well as mitochondrial 16S rRNA and COI DNA from 56 taxa, we reconstructed the phylogeny of Euthyneura utilising Maximum Likelihood and Bayesian inference methods. The evolution of colonization of freshwater and terrestrial habitats by pulmonate Euthyneura, considered crucial in the evolution of this group of Gastropoda, is reconstructed with Bayesian approaches. Results We found several well supported clades within Euthyneura, however, we could not confirm the traditional classification, since Pulmonata are paraphyletic and Opistobranchia are either polyphyletic or paraphyletic with several clades clearly distinguishable. Sacoglossa appear separately from the rest of the Opisthobranchia as sister taxon to basal Pulmonata. Within Pulmonata, Basommatophora are paraphyletic and Hygrophila and Eupulmonata form monophyletic clades. Pyramidelloidea are placed within Euthyneura rendering the Euthyneura paraphyletic. Conclusion Based on the current phylogeny, it can be proposed for the first time that invasion of freshwater by Pulmonata is a unique evolutionary event and has taken place directly from the marine environment via an aquatic pathway. The origin of colonisation of terrestrial habitats is seeded in marginal zones and has probably occurred via estuaries or semi-terrestrial habitats such as mangroves. PMID:18294406

  1. [Predation of Lymnaea (Galba) truncatula M黮ler by Zonitoides nitidus M黮ler (Mollusca Gastropoda Pulmonata) (author's transl)].

    PubMed

    Rondelaud, D

    1975-01-01

    Zonitoides nitidus is omnivorous with carnivorous tendancies: the presence of food coming from snails is required for growth of this predator. This snail is not selective for the choice of its preys. Zonitoides cannot be taken for an absolute predator for all growing periods of Lymnaea truncatula: eggs and large snails are not eaten. This species can be cannibal. PMID:1211765

  2. Sperm chemotaxis has been described in numerous species from four invertebrate phyla: Cnidaria, Mollusca,

    E-print Network

    Vogt, Richard G.

    of the species in which sperm chemotaxis occurred. Recent work on coral and tunicate sperm attractants has, 1992; R. L. Miller, unpublished data). The sperm attractant of the tunicate Ciona intestinalis appears

  3. Temporal dynamics of amino and fatty acid composition in the razor clam Ensis siliqua (Mollusca: Bivalvia)

    NASA Astrophysics Data System (ADS)

    Baptista, Miguel; Repolho, Tiago; Maulvault, Ana Lu韘a; Lopes, Vanessa M.; Narciso, Luis; Marques, Ant髇io; Bandarra, Narcisa; Rosa, Rui

    2014-12-01

    Few studies have been conducted on the temporal dynamics of both amino acid (AA) and fatty acid (FA) profiles in marine bivalves. We investigated the seasonal variation of these compounds in the pod razor clam Ensis siliqua in relation to food availability, salinity, water temperature and reproductive cycle. AA content varied between 46.94 and 54.67 % dry weight (DW), and the AAs found in greater quantity were glutamic acid, glycine and aspartic acid. FA content varied between 34.02 and 87.94 mg g-1 DW and the FAs found in greater quantity were 16:0 and 22:6 n-3. Seasonal trends were observed for AAs and FAs. FAs increased with gametogenesis and decreased with spawning while AA content increased throughout spawning. The effect of increasing temperature and high food availability during the spawning season masked the loss of AAs resulting from gamete release. Still, a comparatively greater increase in the contents of glutamic acid and leucine with spawning indicate their possible involvement in a post-spawning gonad recovery mechanism. A post-spawning decrease in 14:0, 16:0, 16:1 n-7, 18:1 n-7 and 18:1 n-9 is indicative of the importance of these FAs in bivalve eggs. An increase in 18:3 n-3, 18:4 n-3, 20:1 n-9 and 20:2 n-6 during gametogenesis suggests their involvement in oocyte maturation. The FA 22:4 n-6, while increasing with spawning, appears to play a role in post-spawning gonad recovery. Salinity did not have an effect on the AA composition. None of the environmental parameters measured had an effect on FA composition.

  4. Melanoides tuberculata (Mollusca: Thiaridae) as an intermediate host of Centrocestus formosanus (Trematoda: Heterophyidae) in Brazil.

    PubMed

    Pinto, Hudson Alves; de Melo, Alan Lane

    2010-01-01

    Pleurolophocercous cercariae emerged from naturally infected Melanoides tuberculata from Minas Gerais State, Brazil, were used to perform experimental infection of laboratory-reared Poecilia reticulata. Mature metacercariae were obtained from the gills of fishes and force-fed to Mus musculus. The adult parasites which recovered from small intestines of mice were identified as Centrocestus formosanus. This is the first report of M. tuberculata as intermediate host of this heterophyid in Brazil. PMID:21748229

  5. Supplement 15, Parasite-Subject Catalogue, Parasites: Arthropoda, Mesozoa, Coelenterata, Mollusca, And Annelida

    E-print Network

    Humphrey, Judith M.; Segal, Dorothy B.; Beard, Mary I.; Edwards, Shirley J.; Kirby, Margie D.

    1966-01-01

    Actornithophilus flavipes (Giebel), l87b Charadrius squatarola Actornithophilus flumineus Clay, 1962 Actitis hypoleucos Timmermann, G., I962 c, 1^2, 143, 3Mi fig- 12 Bechet, I., ?961 b, 91 Rumania Bechet, I., 1961 b, 91 Rumania Brelih, S.; and Tovornik... Blagovescenskij, 1940 Lymnocryptes minima Actornithophilus ochraceus (Nitzsch), 1818 Charadrius dubius curon- icus Charadrius hiaticula tun- drae Squatarola s. squatarola Actornithophilus paludo- sus Clay, 1962 Tringa n. nebularia Actornithophilus...

  6. Evidence for the main foot protein gene in Perna perna (Mollusca, Mytilidae).

    PubMed

    Clezar, C; Weber, L I; Malaquias, G S; Silva, P O

    2008-01-01

    Here, we investigated the gene that encodes the main protein component of the byssus in Perna perna (Ppfp) using a consensus fluorescent probe for the Mytilus group and by polymerase chain reaction amplification using specific and random primers. A 524-bp fragment resulting from polymerase chain reaction amplification was found to be homologous to the fp-1 gene of Mytilus coruscus. This fragment was identified as the 3' end of the Ppfp-1 gene, which included the heptapeptide coding sequence for Lys-Pro-Ser-Tyr-Pro-Pro-Ter (probably the incomplete last tandem repeat unit of the giant exon), the stop codon and the polyadenylation signal. PMID:18752182

  7. A biomechanical model of rock drilling in the piddock Barnea candida (Bivalvia; Mollusca)

    PubMed Central

    Nederlof, Ralf; Muller, Mees

    2012-01-01

    The bivalve Barnea candida (Pholadacea) makes its burrow in clay, soft rock and peat. Barnea has developed a number of adaptations to accommodate this lifestyle. Four muscles enable burrowing. These are situated around a dorsal pivot in such a way that the piddock is able to rotate the shells around two approximate orthogonal axes. The anterior adductor muscle anterior (AAM-A) and the posterior adductor muscle rotate the shells around a dorso-ventral axis; the anterior adductor muscle posterior (AAM-P) and the ventral adductor muscle rotate the shells around an antero-posterior axis. The AAM-A and the AAM-P have evolved from a single anterior adductor muscle and are attached to a piece of the shell that is folded inside out, the umbonal reflection. At the dorsal side of the piddock, the shell margins are reduced. This prevents collision of these margins during movement. Electrical stimulation experiments revealed that the opening of the antero-ventral side of the piddock is faster than its closure. These results were incorporated into a computer model that could simulate shell movements. The computer model allowed predictions about the shapes of burrows and scrape marks. As in Nature, simulated burrows had a long droplet shape with straight scrape marks. PMID:22696480

  8. Using DNA barcoding to differentiate invasive Dreissena爏pecies (Mollusca, Bivalvia).

    PubMed

    Marescaux, Jonathan; Van Doninck, Karine

    2013-12-30

    The zebra mussel (Dreissena polymorpha) and the quagga mussel (Dreissena rostriformis bugensis) are considered as the most competitive invaders in freshwaters of Europe and North America. Although shell characteristics exist to differentiate both species, phenotypic plasticity in the genus Dreissena does not always allow a clear identification. Therefore, the need to find an accurate identification method is essential. DNA barcoding has been proven to be an adequate procedure to discriminate species. The cytochrome c oxidase subunit I mitochondrial gene (COI) is considered as the standard barcode for animals. We tested the use of this gene as an efficient DNA barcode and found that it allow rapid and accurate identification of adult Dreissena individuals. PMID:24453560

  9. Food intake and growth in Macoma balthica (mollusca) in the laboratory

    NASA Astrophysics Data System (ADS)

    Hummel, H.

    Groups of Macoma balthica were kept during 4-week periods in an experimental set up at a constant temperature and food concentration. Food concentrations (expressed in particulate organic carbon) for the different groups ranged from 0 to 16 mg C稩 -1. The experiment was repeated 6 times, viz. in different months, and the temperatures were changed accordingly to correspond with levels found in the field. The rates of food intake, water clearance and growth were followed throughout the experiment. The flagellate Isochrysis galbana served as food. With increasing food concentration all 3 rates (food intake, water clearance and growth) increased up to maximum to decrease again at high food concentrations. Such bell-shaped relationships were observed in all seasons. The dependence of growth on food concentration was similar in all seasons. Zero growth or weight losses were observed at food concentrations below 1.3 mg C稩 -1, and maximum growth rates were reached at food concentrations between 5 and 7 mg C稩 -1. The daily maintenance ration amounted to about 1.2% of the body weight. Seasonal differences were observed in the relationships of the rates of both water clearance and food intake with food concentration. During the winter and spring the optimum curves for these relationships reached their maximum at food concentrations of 8 to 10 mg C稩 -1. During summer and early autumn the optimum curves were shifted to lower food concentrations, around 2 to 4 mg C稩 -1, probably as an adaptation to low food concentrations observed in the field during these periods.

  10. Ultrastructure developments during spermiogenesis in Polydora ciliata (Annelida: Spionidae), a parasite of mollusca

    NASA Astrophysics Data System (ADS)

    Gao, Yan; Zhang, Tao; Zhang, Libin; Qiu, Tianlong; Xue, Dongxiu; Yang, Hongsheng

    2014-12-01

    Spionid worms of Polydora ciliata inhabit the shells of many commercially important bivalves and cause disease in molluscan aquaculture. Their sperm structure is closely related to their fertilization method. To give an insight into the sperm structure and spermatogenesis, ultrastructure details of the subcellular components of germ cells during spermiogenesis of Polydora ciliata are detected by transmission electron microscopy (TEM). In P. ciliata, during spermiogenesis, chromatin is regularly arranged as dense fibrils and becomes more condensed when the nucleus elongates. Microtubules do not surround the nucleus during its elongation. The Golgi phase is characterized by the formation of proacrosomal granules within the Golgi apparatus. The proacrosomal granules fuse to form a single, spherical acrosomal vesicle that migrates to the anterior pole of the cell. At the time of nuclear condensation, mitochondria become reduced in number but increased in size, causing deep indentation at the base of the nucleus. The mid-piece has a few mitochondria. The cap phase includes the spreading of the acrosomal granule over the surface of the nucleus of the differentiating spermatid. The acrosomal phase of spermiogenesis is typically associated with changes in the shape of the nucleus, acrosome and tail. The relationship of sperm ultrastructure to spermiogenesis in spionidae species was discussed.

  11. Genetic sex determination, gender identification and pseudohermaphroditism in the knobbed whelk, Busycon carica (Mollusca: Melongenidae).

    PubMed Central

    Avise, John C.; Power, Alan J.; Walker, DeEtte

    2004-01-01

    We report perhaps the first genic-level molecular documentation of a mammalian-like 'X-linked' mode of sex determination in molluscs. From family inheritance data and observed associations between sex-phenotyped adults and genotypes in Busycon carica, we deduce that a polymorphic microsatellite locus (bc2.2) is diploid and usually heterozygous in females, hemizygous in males, and that its alleles are transmitted from mothers to sons and daughters but from fathers to daughters only. We also employ bc2.2 to estimate near-conception sex ratio in whelk embryos, where gender is indeterminable by visual inspection. Statistical corrections are suggested at both family and population levels to accommodate the presence of homozygous bc2.2 females that could otherwise be genetically mistaken for hemizygous males. Knobbed whelks were thought to be sequential hermaphrodites, but our evidence for genetic dioecy supports an earlier hypothesis that whelks are pseudohermaphroditic (falsely appear to switch functional sex when environmental conditions induce changes in sexual phenotype). These findings highlight the distinction between gender in a genetic versus phenotypic sense. PMID:15156923

  12. Comparative Analysis of Chromosome Counts Infers Three Paleopolyploidies in the Mollusca

    PubMed Central

    Hallinan, Nathaniel M.; Lindberg, David R.

    2011-01-01

    The study of paleopolyploidies requires the comparison of multiple whole genome sequences. If the branches of a phylogeny on which a whole-genome duplication (WGD) occurred could be identified before genome sequencing, taxa could be selected that provided a better assessment of that genome duplication. Here, we describe a likelihood model in which the number of chromosomes in a genome evolves according to a Markov process with one rate of chromosome duplication and loss that is proportional to the number of chromosomes in the genome and another stochastic rate at which every chromosome in the genome could duplicate in a single event. We compare the maximum likelihoods of a model in which the genome duplication rate varies to one in which it is fixed at zero using the Akaike information criterion, to determine if a model with WGDs is a good fit for the data. Once it has been determined that the data does fit the WGD model, we infer the phylogenetic position of paleopolyploidies by calculating the posterior probability that a WGD occurred on each branch of the taxon tree. Here, we apply this model to a molluscan tree represented by 124 taxa and infer three putative WGD events. In the Gastropoda, we identify a single branch within the Hypsogastropoda and one of two branches at the base of the Stylommatophora. We also identify one or two branches near the base of the Cephalopoda. PMID:21859805

  13. Using DNA barcoding to differentiate invasive Dreissena爏pecies (Mollusca, Bivalvia)

    PubMed Central

    Marescaux, Jonathan; Van Doninck, Karine

    2013-01-01

    Abstract The zebra mussel (Dreissena polymorpha) and the quagga mussel (Dreissena rostriformis bugensis) are considered as the most competitive invaders in freshwaters of Europe and North America. Although shell characteristics exist to differentiate both species, phenotypic plasticity in the genus Dreissena does not always allow a clear identification. Therefore, the need to find an accurate identification method is essential. DNA barcoding has been proven to be an adequate procedure to discriminate species. The cytochrome c oxidase subunit I mitochondrial gene (COI) is considered as the standard barcode for animals. We tested the use of this gene as an efficient DNA barcode and found that it allow rapid and accurate identification of adult Dreissena individuals. PMID:24453560

  14. Gastrocopta (Mollusca, Gastropoda, Pupillidae) in爐he燩ilbara region of Western Australia.

    PubMed

    Whisson, Corey S; K鰄ler, Frank

    2013-01-01

    Six species of Gastrocopta have been identified from the Pilbara region, Western Australia, by means of comparative analyses of shell and mtDNA variation. Three of these species, Gastrocopta hedleyi, Gastrocopta larapinta and Gastrocopta servilis, have been recorded in the Pilbara for the first time. Gastrocopta sp. CW1 is probably new to science and might be endemic to the region. By contrast, Gastrocopta hedleyi, Gastrocopta larapinta and Gastrocopta mussoni are shown to be widespread. PMID:23653507

  15. Gastrocopta (Mollusca, Gastropoda, Pupillidae) in爐he燩ilbara region of Western Australia

    PubMed Central

    Whisson, Corey S.; K鰄ler, Frank

    2013-01-01

    Abstract Six species of Gastrocopta have been identified from the Pilbara region, Western Australia, by means of comparative analyses of shell and mtDNA variation. Three of these species, Gastrocopta hedleyi, Gastrocopta larapinta and Gastrocopta servilis, have been recorded in the Pilbara for the first time. Gastrocopta sp. CW1 is probably new to science and might be endemic to the region. By contrast, Gastrocopta hedleyi, Gastrocopta larapinta and Gastrocopta mussoni are shown to be widespread. PMID:23653507

  16. Use of axonal projection patterns for the homologisation of cerebral nerves in Opisthobranchia, Mollusca and Gastropoda

    PubMed Central

    2013-01-01

    Introduction Gastropoda are guided by several sensory organs in the head region, referred to as cephalic sensory organs (CSOs). These CSOs are innervated by distinct nerves. This study proposes a unified terminology for the cerebral nerves and the categories of CSOs and then investigates the neuroanatomy and cellular innervation patterns of these cerebral nerves, in order to homologise them. The homologisation of the cerebral nerves in conjunction with other data, e.g. ontogenetic development or functional morphology, may then provide insights into the homology of the CSOs themselves. Results Nickel-lysine axonal tracing (揵ackfilling) was used to stain the somata projecting into specific nerves in representatives of opisthobranch Gastropoda. Tracing patterns revealed the occurrence, size and relative position of somata and their axons and enabled these somata to be mapped to specific cell clusters. Assignment of cells to clusters followed a conservative approach based primarily on relative location of the cells. Each of the four investigated cerebral nerves could be uniquely identified due to a characteristic set of soma clusters projecting into the respective nerves via their axonal pathways. Conclusions As the described tracing patterns are highly conserved morphological characters, they can be used to homologise nerves within the investigated group of gastropods. The combination of adequate number of replicates and a comparative approach allows us to provide preliminary hypotheses on homologies for the cerebral nerves. Based on the hypotheses regarding cerebral nerve homology together with further data on ultrastructure and immunohistochemistry of CSOs published elsewhere, we can propose preliminary hypotheses regarding homology for the CSOs of the Opisthobranchia themselves. PMID:23597272

  17. Characterization of 15 microsatellite loci in the pulmonate snail Pseudosuccinea columella (Mollusca, Gastropoda)

    Microsoft Academic Search

    ANTOINE NICOT; MARIE-PIERRE DUBOIS; CHANTAL DEBAIN; PATRICE DAVID; PHILIPPE JARNE

    2008-01-01

    We characterized 15 new variable microsatellites in the freshwater snail Pseudosuccinea (Lymnaea) columella, as well as conditions for multiplexing and simultaneously genotyping sets of loci. Two to six alleles were detected per locus over the six populations studied. Gene diversity ranged from 0.000 to 0.498, but essentially no heterozygous individuals were observed. This resulted in extremely high FIS estimates, and

  18. Colonization of Fresh Waters in the Republic of South Africa by Lymnaea columella Say (Mollusca : Gastropoda)

    Microsoft Academic Search

    J. A. van Eeden

    1966-01-01

    Lymnaea (Pseudosuccinea) columella Say 1817, described from specimens probably obtained in the vicinity of Philadelphia1, is widely distributed in still and slow-flowing waters in the eastern United States of America, Mexico, Central America, Cuba and the northern and central regions of South America1,2. Fossil specimens are known from the Pleistocene of North America, and another species of the sub-genus has

  19. Characterization of 15 microsatellite loci in the pulmonate snail Pseudosuccinea columella (Mollusca, Gastropoda).

    PubMed

    Nicot, Antoine; Dubois, Marie-Pierre; Debain, Chantal; David, Patrice; Jarne, Philippe

    2008-11-01

    We characterized 15 new variable microsatellites in the freshwater snail Pseudosuccinea (Lymnaea) columella, as well as conditions for multiplexing and simultaneously genotyping sets of loci. Two to six alleles were detected per locus over the six populations studied. Gene diversity ranged from 0.000 to 0.498, but essentially no heterozygous individuals were observed. This resulted in extremely high F(IS) estimates, and therefore high selfing rates. The F(ST) estimates ranged from 0.18 to 1 among populations, but was generally high. These markers will constitute efficient tools for investigating the population structure of this invasive species. Cross-species amplification was on the whole unsuccessful. PMID:21586021

  20. Life history of the bathyal octopus Pteroctopus tetracirrhus (Mollusca, Cephalopoda) in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Quetglas, Antoni; Ordines, Francesc; Gonz醠ez, Mar韆; Franco, Ignacio

    2009-08-01

    The life cycle of the deep-sea octopus Pteroctopus tetracirrhus was studied from monthly samples obtained throughout the year in different areas of the western Mediterranean (mainly around the Balearic Islands and along the coast of the Iberian Peninsula). A total of 373 individuals (205 females, 168 males) were analyzed; females ranged from 4.5 to 14.0 cm mantle length (ML) and males from 4.5 to 11.5 cm ML. There were few small-sized octopuses (<7 cm ML) in the samples, which might indicate that these individuals inhabit rocky grounds that are not accessible to trawlers or waters deeper than the maximum depth sampled (800 m). The species occurred more frequently around the Balearic Islands than along the Iberian Peninsula as they appeared in 20% and 7%, respectively, of the hauls in these areas. The octopus inhabits the lower continental shelf and upper slope in both areas, primarily between 200 and 500 m depth. Modal lengths were followed from autumn, when recruits were caught by trawlers, to summer, when reproduction took place. Females grew from 8 to 10 cm ML from winter to spring, but this modal size did not increase further in summer; males grew from 7 to 9 cm ML from winter to spring. The total disappearance of large individuals after summer suggests a life cycle lasting a single year. The evolution of the monthly mean sizes showed that the growth was best described by log-linear functions in both sexes. The length at first maturity was clearly higher in females (12 cm ML) than in males (8 cm ML). A total of 30 different prey items, belonging to four major taxonomic groups (crustaceans, osteichthyes, cephalopods and gastropods), were identified in the stomach contents. The diet of the octopus was based on crustaceans and teleosts, which accounted for 75% and 23% of the prey items, respectively. Cephalopods and gastropods were accessory prey as they only represented 1.6% and 0.7%, respectively, of the total. The octopus showed a marked preference for the benthic fish Symphurus nigrescens and the endobenthic crustacean Alpheus glaber. The bathymetric distribution of P. tetracirrhus coincides with those of these two main prey, which suggests that the distribution of the octopus might be strongly linked to its trophic resources.

  1. Ultrastructure of the mature spermatozoon of the bivalve Scapharca broughtoni (Mollusca: Bivalvia: Arcidae).

    PubMed

    Zhu, Jun-Quan; Dahms, Hans-Uwe; Yang, Wan-Xi

    2008-12-01

    The ultrastructure of mature spermatozoa of the giant clam bivalve Scapharca broughtoni was investigated by transmission electron microscopy for the first time. The mature spermatozoon consists of a head which is composed of a cone-shaped acrosome, a round nucleus, and a tail region. A subacrosomal space contains an axial rod and a basal plate, the latter lying between the acrosome and the nucleus. Although the nucleus lacks an anterior invagination, an inverted shallow V-shaped posterior invagination is present within the nucleus. Within the middle portion of the spermatozoon lie five spherical mitochondria while the long whip-like end portion is composed of an axoneme with the typical 9+2 structure. Our conclusion is that the spermatozoon of S. broughtoni is of the type I anacrosomal "aquasperm", and the morphology of acrosome and nucleus are an adaptation to external fertilization. PMID:18539466

  2. Morphology of the symbiosis between Corculum cardissa (Mollusca: Bivalvia) and Symbiodinium corculorum (Dinophyceae).

    PubMed

    Farmer, M A; Fitt, W K; Trench, R K

    2001-06-01

    Light and transmission electron microscopy of tissues of the symbiotic clam Corculum cardissa (L) showed that a symbiotic dinoflagellate, Symbiodinium corculorum (Trench), is found predominantly in the mantle and the gills. The data suggest that in C. cardissa the algae are located in a zooxanthellal tubular system that is associated with the hemocoel and is similar to that seen in tridacnine ("giant") clams. The algae occur within the lumen of the tertiary tubules and are thus separated from the hemolymph by a tissue that is one cell layer thick. Under a light microscope the tertiary tubules appear as rows of symbionts originating from the digestive diverticulum, presumably branching from the primary tubules that are also seen in symbiotic tridacnine clams. This morphological arrangement is discussed with regard to the ontogeny and the evolution of the tubular system within symbiotic bivalves. PMID:11441975

  3. Molecular phylogeny of pearl oysters and their relatives (Mollusca, Bivalvia, Pterioidea)

    PubMed Central

    2010-01-01

    Background The superfamily Pterioidea is a morphologically and ecologically diverse lineage of epifaunal marine bivalves distributed throughout the tropical and subtropical continental shelf regions. This group includes commercially important pearl culture species and model organisms used for medical studies of biomineralization. Recent morphological treatment of selected pterioideans and molecular phylogenetic analyses of higher-level relationships in Bivalvia have challenged the traditional view that pterioidean families are monophyletic. This issue is examined here in light of molecular data sets composed of DNA sequences for nuclear and mitochondrial loci, and a published character data set of anatomical and shell morphological characters. Results The present study is the first comprehensive species-level analysis of the Pterioidea to produce a well-resolved, robust phylogenetic hypothesis for nearly all extant taxa. The data were analyzed for potential biases due to taxon and character sampling, and idiosyncracies of different molecular evolutionary processes. The congruence and contribution of different partitions were quantified, and the sensitivity of clade stability to alignment parameters was explored. Conclusions Four primary conclusions were reached: (1) the results strongly supported the monophyly of the Pterioidea; (2) none of the previously defined families (except for the monotypic Pulvinitidae) were monophyletic; (3) the arrangement of the genera was novel and unanticipated, however strongly supported and robust to changes in alignment parameters; and (4) optimizing key morphological characters onto topologies derived from the analysis of molecular data revealed many instances of homoplasy and uncovered synapomorphies for major nodes. Additionally, a complete species-level sampling of the genus Pinctada provided further insights into the on-going controversy regarding the taxonomic identity of major pearl culture species. PMID:21059254

  4. Molecular phylogenetic investigations of the relationships of the echinoderm-parasite family Eulimidae within Hypsogastropoda (Mollusca).

    PubMed

    Takano, Tsuyoshi; Kano, Yasunori

    2014-10-01

    The gastropod family Eulimidae has attracted considerable attention as one of the most diverse groups of parasitic molluscs in terms of number of species and ranges of body plans and parasitic strategies. However, the phylogenetic position of the family has not been established within the Hypsogastropoda and this has hampered the inference of ancestral states in the evolution of the morphology and parasitic strategies. Here we present Bayesian and maximum likelihood phylograms of Hypsogastropoda based on nuclear and mitochondrial loci (18S and 28S rRNA, Histone H3, COI and 16S rRNA) and a better taxonomic sampling than in previous molecular analyses, to determine the position of Eulimidae. The resulting trees suggest Vanikoridae as the sister group of Eulimidae; the two families are collectively placed in the newly redefined superfamily Vanikoroidea, with Truncatelloidea and (potentially paraphyletic) Rissooidea as closest relatives. Vanikorids are protandrous hermaphrodites as are many eulimids and are essentially carnivorous, differing from the mostly gonochoristic and herbivorous/detritivorous Truncatelloidea and Rissooidea. The mode of feeding may have a phylogenetic signal also within Eulimidae, where radula-less species constitute a robust clade. Other new findings include a close affinity of the submarine-cave Pickworthiidae to Cerithioidea and a terminal position of Nystiellidae within the paraphyletic Epitoniidae. PMID:24994027

  5. [Polyplacophoran communities (Mollusca: Polyplacophora) at Bahia de La Paz, Baja California Sur, M閤ico].

    PubMed

    Garc韆 R韔s, Cedar I; Alvarez Ruiz, Migdalia

    2007-03-01

    Eight species of polyplacophorans have been reported from La Bahia de la Paz, Baja California Sur, Mexico. We add Lepidochitona beanii, Chaetopleura lurida, Stenoplax limaciformis, S. mariposa, Lepidozona clathrata, L. serrata and Acanthochitona arragonites, increasing the known number of species to 15. Ordination analysis of five chiton communities at the site suggests a correlation of wave exposure to species composition and diversity: communities with intermediate wave exposure have more species (richness) and higher diversity (Shannon's index). PMID:18457125

  6. Competition for the home and aggressive behaviour in the chiton Acanthopleura gemmata (Blainville) (Mollusca: Polyplacophora)

    Microsoft Academic Search

    Guido Chelazzi; Stefano Focardi; Jean Louis Deneubourg; Riccardo Innocenti

    1983-01-01

    Computerized screening of all the positions recorded during a synodic month on 120 individually marked chitons (Acanthopleura gemmata) pinpointed their preferential resting points. Unlike the majority of intertidal chitons so far studied, A. gemmata rests in well-defined homes actively dug in the rock. Homes proved to be not strictly individual and periodically interchangeable. A complex aggressive behaviour was recorded in

  7. Sperm morphology, spermatogenesis and spermiogenesis of three species of chitons (Mollusca, Polyplacophora)

    Microsoft Academic Search

    E. R. Sakker

    1984-01-01

    Mature sperm of the three species, Onithochiton quercinus, Chiton pelliserpentis and Plaxiphora paeteliana are eupyrene and basically of the 損rimitive type. The sperm are small, with a distinct head, midpiece with a few spherical to oval mitochondria and a long tail with a (29)+2 axoneme. They are unusual among primitive sperm in being bilaterally symmetrical, with a long anterior filament

  8. A comparative study on the movement patterns of two sympatric tropical chitons (Mollusca: Polyplacophora)

    Microsoft Academic Search

    G. Chelazzi; S. Focardi; J. L. Deneubourg

    1983-01-01

    The individual positions of 200 intertidal chitons [Acanthopleura brevispinosa (Sowerby) and A. gemmata (Blainville)] were recorded throughout 55 low tides on a Somalian shore, using a discrete sampling method. Both species feed during nocturnal low tide and rest during the day and high tide. Due to this activity rhythm, individual positions recorded during diurnal and nocturnal low tides give information

  9. Fine structure and immunocytochemistry of a new chemosensory system in the Chiton larva (Mollusca: Polyplacophora).

    PubMed

    Haszprunar, Gerhard; Friedrich, Stefan; Wanninger, Andreas; Ruthensteiner, Bernhard

    2002-02-01

    Combined electron microscopy and immunocytochemistry of the larvae of several polyplacophoran species (Chiton olivaceus, Lepidochitona aff. corrugata, Mopalia muscosa) revealed a sensory system new to science, a so-called "ampullary system." The cells of the "ampullary system" are arranged in four symmetrically situated pairs lying dorsolaterally and ventrolaterally in the pretrochal part of the trochophore-like larva and they send axons into the cerebral commissure. They are lost at metamorphosis. The fine structure of these cells strongly resembles that of so-called "ampullary cells" known from various sensory organs of other molluscs, such as the apical complex of gastropod and bivalve larvae, osphradia of vetigastropods, and olfactory organs of cephalopods, and nuchal organs of certain polychaetes. The ampullary cells and their nerves are densely stained by anti-FMRF-amide fluorescence dyes, whereas antiserotonin staining is only weak. While cytological homology of the ampullary cells with those of other organs is probable, the ampullary system as a whole is regarded as a synapomorphy of the Polyplacophora or Chitonida. PMID:11748704

  10. Proteomic analysis from the mineralized radular teeth of the giant Pacific chiton, Cryptochiton stelleri (Mollusca).

    PubMed

    Nemoto, Michiko; Wang, Qianqian; Li, Dongsheng; Pan, Songqin; Matsunaga, Tadashi; Kisailus, David

    2012-09-01

    The biomineralized radular teeth of chitons are known to consist of iron-based magnetic crystals, associated with the maximum hardness and stiffness of any biomineral. Based on our transmission electron microscopy analysis of partially mineralized teeth, we suggest that the organic matrix within the teeth controls the iron oxide nucleation. Thus, we used Nano-LC-MS to perform a proteomic analysis of the organic matrix in radular teeth of the chiton Cryptochiton stelleri in order to identify the proteins involved in the biomineralization process. Since the genome sequence of C. stelleri is not available, cross-species similarity searching and de novo peptide sequencing were used to screen the proteins. Our results indicate that several proteins were dominant in the mineralized part of the radular teeth, amongst which, myoglobin and a highly acidic peptide were identified as possibly involved in the biomineralization process. PMID:22833255

  11. New records for the shallow-water chiton fauna (Mollusca, Polyplacophora) of the Azores (NE Atlantic).

    PubMed

    Avila, S閞gio P; Sigwart, Julia

    2013-01-01

    Published records, original data from recent field work on all of the islands of the Azores (NE Atlantic), and a revision of the entire mollusc collection deposited in the Department of Biology of the University of the Azores (DBUA) were used to compile a checklist of the shallow-water Polyplacophora of the Azores. Lepidochitona cf. canariensis and Tonicella rubra are reported for the first time for this archipelago, increasing the recorded Azorean fauna to seven species. PMID:23825446

  12. Ultrastructure of the pericardium in chitons (Mollusca: Polyplacophora), in relation to filtration and contraction mechanisms

    Microsoft Academic Search

    Steinar 豮land

    1981-01-01

    The pericardium in Lepidopleurus asellus (Spengler), Tonicella marmorea (Fabricius), T. rubra L., Ischnochiton albus L., and Calleochiton laevis (Montagu), species taxonomically far apart, is described. It consists of a flat, simple epithelium facing the pericardial cavity, a basement membrane, a muscle layer with two types of muscle fibres, nerve processes, glio-interstitial cells, and fibrocytes, embedded in a loose collagen matrix.

  13. Ross Sea Mollusca from the Latitudinal Gradient Program: R/V Italica 2004 Rauschert dredge samples.

    PubMed

    Ghiglione, Claudio; Alvaro, Maria Chiara; Griffiths, Huw J; Linse, Katrin; Schiaparelli, Stefano

    2013-01-01

    Information regarding the molluscs in this dataset is based on the Rauschert dredge samples collected during the Latitudinal Gradient Program (LGP) on board the R/V "Italica" in the Ross Sea (Antarctica) in the austral summer 2004. A total of 18 epibenthic dredge deployments/samplings have been performed at four different locations at depths ranging from 84 to 515m by using a Rauschert dredge with a mesh size of 500?m. In total 8,359 specimens have been collected belonging to a total of 161 species. Considering this dataset in terms of occurrences, it corresponds to 505 discrete distributional records (incidence data). Of these, in order of abundance, 5,965 specimens were Gastropoda (accounting for 113 species), 1,323 were Bivalvia (accounting for 36 species), 949 were Aplacophora (accounting for 7 species), 74 specimens were Scaphopoda (3 species), 38 were Monoplacophora (1 species) and, finally, 10 specimens were Polyplacophora (1 species). This data set represents the first large-scale survey of benthic micro-molluscs for the area and provides important information about the distribution of several species, which have been seldom or never recorded before in the Ross Sea. All vouchers are permanently stored at the Italian National Antarctic Museum (MNA), Section of Genoa, enabling future comparison and crosschecking. This material is also currently under study, from a molecular point of view, by the barcoding project "BAMBi" (PNRA 2010/A1.10). PMID:24146597

  14. Die 膕theten mit intrapigment鋜em Schalenauge von Chiton marmoratus L. (Mollusca, Placophora)

    Microsoft Academic Search

    Winfried Haas; Klaus Kriesten

    1978-01-01

    Summary Shape and fine structure of the aesthetes located in the uppermost calcareous layer of the shell plates (tegmentum) ofChiton marmoratus L. were demonstrated. Special interest was given to the intrapigmental eye which is laterally inserted in the aesthete body. It consists of a calcareous lens derived from the tegmentum, sensory cells with long microvilli at their distal end forming

  15. The continuing debate on deep molluscan phylogeny: evidence for Serialia (Mollusca, Monoplacophora + Polyplacophora).

    PubMed

    St鰃er, I; Sigwart, J D; Kano, Y; Knebelsberger, T; Marshall, B A; Schwabe, E; Schr鰀l, M

    2013-01-01

    Molluscs are a diverse animal phylum with a formidable fossil record. Although there is little doubt about the monophyly of the eight extant classes, relationships between these groups are controversial. We analysed a comprehensive multilocus molecular data set for molluscs, the first to include multiple species from all classes, including five monoplacophorans in both extant families. Our analyses of five markers resolve two major clades: the first includes gastropods and bivalves sister to Serialia (monoplacophorans and chitons), and the second comprises scaphopods sister to aplacophorans and cephalopods. Traditional groupings such as Testaria, Aculifera, and Conchifera are rejected by our data with significant Approximately Unbiased (AU) test values. A new molecular clock indicates that molluscs had a terminal Precambrian origin with rapid divergence of all eight extant classes in the Cambrian. The recovery of Serialia as a derived, Late Cambrian clade is potentially in line with the stratigraphic chronology of morphologically heterogeneous early mollusc fossils. Serialia is in conflict with traditional molluscan classifications and recent phylogenomic data. Yet our hypothesis, as others from molecular data, implies frequent molluscan shell and body transformations by heterochronic shifts in development and multiple convergent adaptations, leading to the variable shells and body plans in extant lineages. PMID:24350268

  16. Chiton integument: Ultrastructure of the sensory hairs of Mopalia muscosa (Mollusca: Polyplacophora)

    Microsoft Academic Search

    Esther M. Leise; Richard A. Cloney

    1982-01-01

    The dorsal integument of the girdle of the chiton Mopalia muscosa is covered by a chitinous cuticle about 0.1 mm in thickness. Within the cuticle are fusiform spicules composed of a central mass of pigment granules surrounded by a layer of calcium carbonate crystals. Tapered, curved chitinous hairs with a groove on the mesial surface pass through the cuticle and

  17. The role of the follicle cells during oogenesis in the chiton Sypharochiton septentriones (Ashby) (Polyplacaphora, Mollusca)

    Microsoft Academic Search

    Lynne Selwood

    1970-01-01

    Histochemical studies and electron microscopic investigations on the role of the follicle cells during oogenesis in the chiton Sypharochiton septentriones showed that the main role of the follicle cells was the deposition of a spiny chorion around each oocyte. The chorion was composed of three layers; an inner, acid mucopolysaccharide layer, which was a primary egg membrane secreted by Golgi

  18. Fine structure of the mineralized teeth of the chiton Acanthopleura echinata (Mollusca: Polyplacophora).

    PubMed

    Wealthall, Rosamund J; Brooker, Lesley R; Macey, David J; Griffin, Brendan J

    2005-08-01

    The major lateral teeth of the chiton Acanthopleura echinata are composite structures composed of three distinct mineral zones: a posterior layer of magnetite; a thin band of lepidocrocite just anterior to this; and apatite throughout the core and anterior regions of the cusp. Biomineralization in these teeth is a matrix-mediated process, in which the minerals are deposited around fibers, with the different biominerals described as occupying architecturally discrete compartments. In this study, a range of scanning electron microscopes was utilized to undertake a detailed in situ investigation of the fine structure of the major lateral teeth. The arrangement of the organic and biomineral components of the tooth is similar throughout the three zones, having no discrete borders between them, and with crystallites of each mineral phase extending into the adjacent mineral zone. Along the posterior surface of the tooth, the organic fibers are arranged in a series of fine parallel lines, but just within the periphery their appearance takes on a "fish scale"-like pattern, reflective of the cross section of a series of units that are overlaid, and offset from each other, in adjacent rows. The units are approximately 2 microm wide and 0.6 microm thick and comprise biomineral plates separated by organic fibers. Two types of subunits make up each "fish scale": one is elongate and curved and forms a trough, in which the other, rod-like unit, is nestled. Adjacent rod and trough units are aligned into large sheets that define the fracture plane of the tooth. The alignment of the plates of rod-trough units is complex and exhibits extreme spatial variation within the tooth cusp. Close to the posterior surface the plates are essentially horizontal and lie in a lateromedial plane, while anteriorly they are almost vertical and lie in the posteroanterior plane. An understanding of the fine structure of the mineralized teeth of chitons, and of the relationship between the organic and mineral components, provides a new insight into biomineralization mechanisms and controls. PMID:15959908

  19. 18S ribosomal DNA sequences provide insight into the phylogeny of patellogastropod limpets (Mollusca: Gastropoda).

    PubMed

    Yoon, Sook Hee; Kim, Won

    2007-02-28

    To investigate the phylogeny of Patellogastropoda, the complete 18S rDNA sequences of nine patellogastropod limpets Cymbula canescens (Gmelin, 1791), Helcion dunkeri (Krauss, 1848), Patella rustica Linnaeus, 1758, Cellana toreuma (Reeve, 1855), Cellana nigrolineata (Reeve, 1854), Nacella magellanica Gmelin, 1791, Nipponacmea concinna (Lischke, 1870), Niveotectura pallida (Gould, 1859), and Lottia dorsuosa Gould, 1859 were determined. These sequences were then analyzed along with the published 18S rDNA sequences of 35 gastropods, one bivalve, and one chiton species. Phylogenetic trees were constructed by maximum parsimony, maximum likelihood, and Bayesian inference. The results of our 18S rDNA sequence analysis strongly support the monophyly of Patellogastropoda and the existence of three subgroups. Of these, two subgroups, the Patelloidea and Acmaeoidea, are closely related, with branching patterns that can be summarized as [(Cymbula + Helcion) + Patella] and [(Nipponacmea + Lottia) + Niveotectura]. The remaining subgroup, Nacelloidea, emerges as basal and paraphyletic, while its genus Cellana is monophyletic. Our analysis also indicates that the Patellogastropoda have a sister relationship with the order Cocculiniformia within the Gastropoda. PMID:17464213

  20. A new Middle Miocene Niveria Jousseaume, 1884 (Mollusca: Gastropoda: Trivioidea) from Hungary

    NASA Astrophysics Data System (ADS)

    Fehse, Dirk

    2011-02-01

    A new species of Niveria from the Middle Miocene (Badenian) of the Paratethys of Borsodb髏a, Hungary is described. This species is characterized by its callused dorsum and dorsal depression. Niveria jozefgregoi sp. nov. is discussed with comparative species from the Badenian of Hungary, the Pliocene of the Mediterranean region, Florida and Recent species from Madeira and the Islas Gal醦agos.

  1. Transformation of soft coral (Coelenterata: Octocorallia) terpenes by Ovula ovum (Mollusca: Prosobranchia)

    Microsoft Academic Search

    J. C. Coll; D. M. Tapiolas; B. F. Bowden; L. Webb; H. Marsh

    1983-01-01

    The faecal pellets from specimens of the prosobranch mollusc Ovula ovum found feeding on the soft coral Sarcophyton sp. at Eclipse Island, Palm Island Group (1846'S; 14633'E) in November 1980 were analysed. The only terpene present in the faeces, 7,8-deoxysarcophytoxide, differed from the major constituent of the soft coral, sarcophytoxide, suggesting that the latter had been transformed into the former

  2. Cytogenetics of Anodonta cygnea (Mollusca: Bivalvia) as possible indicator of environmental adversity

    NASA Astrophysics Data System (ADS)

    Carrilho, J.; Leit鉶, A.; Vicente, C.; Malheiro, I.

    2008-11-01

    Anodonta cygnea is a freshwater clam, belonging to the Unionidae family, which can be found in rivers and lagoons all over Europe and Northern America. As they appear as important case studies for ecological damage assessments, the various species of the Unionidae family have been submitted to a sort of recent studies on their chromosomal or cytogenetic status. In this study we confirmed the diploid chromosome number of 2 n = 38 for this species, and established for the first time the karyotype, which comprised six metacentric, 12 submetacentric and one subtelocentric chromosome pairs. We also found a high percentage of cells with an abnormal number of chromosomes. Considering that karyotype disturbances in Unionids have been previously related with exposure to chemicals, either natural or produced by human activity, we determined the aneuploidy index for our population. The aneuploidy index is an excellent marker for pollutant presence/effect. The animals acclimatized in tap water and in natural water from the lake where the individuals were collected showed different levels of aneuploidy. The higher values were found in tap water. Chromosome analysis techniques seem a suitable tool to study the impact of contaminants referred above, and making A. cygnea a suitable organism for assessment of an eugenic damage in aquatic systems. On the other hand, our results also point out to the importance of doing the acclimatizing process of the collected animals in their own natural water.

  3. What explains the invading success of the aquatic mud snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca)?

    Microsoft Academic Search

    A. Alonso; P. Castro-D韊z

    2008-01-01

    The spread of non-native species is one of the most harmful and least reversible disturbances in ecosystems. Species have\\u000a to overcome several filters to become a pest (transport, establishment, spread and impact). Few studies have checked the traits\\u000a that confer ability to overcome these steps in the same species. The aim of the present study is to review the available

  4. [Mollusc diversity in an Arca zebra (Mollusca: Bivalvia) community, Chacopata, Sucre, Venezuela].

    PubMed

    Prieto, A S; Ruiz, L J; Garc韆, N; Alvarez, M

    2001-06-01

    The diversity of a subtidal epifaunal mollusk community was studied from September, 1990 to September, 1991 in Chacopata, Sucre State, Venezuela. There were 40 species (24 bivalves and 16 gastropods). The diversity indexes (H' = 2.087, J' = 0.392, 1/D = 0.528) were low when compared with other tropical zones. Monthly diversity reached its maximum in September, 1990 (1.63 bits/ind.) and July, 1991 (1.60 bits/ind.); minimum diversity occurred in June, 1991 (0.52 bits/ind.). A Log series model applied to species abundance data showed a straight line with a diversity index alpha of 5.56. Of 40 species identified, the turkeywing Arca zebra was dominant (69% in number of individuals and 72% of biomass) followed by Pinctada imbricata, Modiolus squamosus, Chama macerophyla and Anadara notabilis. The predatory snails Phyllonotus pomum, Chicoreus brevifrons and Murex recurvirostris seemed to have trophic relationships with A. zebra. The total mean biomass in wet weight (469.20 +/- 263 g m-2, shell included) was high which indicates that A. zebra, a species with a rapid growth rate, occupies a central role in the assemblage as an efficient filter feeder that converts planktonic food into available biomass, supporting one of the most important fisheries in Venezuela. PMID:11935909

  5. [Secondary production and condition index in Arca zebra (Mollusca: Vivaldia) in the Gulf of Cariaco, Venezuela].

    PubMed

    Arcas, A P; Omar Ramos, A; Arrieche, D; Villalba, J; Lodeiros, C

    2001-06-01

    Production and condition index of a turkeywing (Arca zebra) population were studied from August 1984 to August 1985 in Pariche, Cariaco Gulf, Venezuela. Production was studied through bimonthly collections using a method designed for populations with continuous reproduction and indistinguishable age classes. The population distribution was stable with a mean density of 37 ind.m-2. A production of 131.61 g dry weight m-2 year-1 was calculated from data on density, biomass and weight increase along the year. Highest production was between February 1985 and August 1985 (65%) and concentrated in individuals 60.00-79.95 mm long (45.73%). There was large seasonal variation in the mean monthly condition index (IC = (Ps/Ph) x 100) in the two size classes examined: it reached a maximum in July 1985 (26.84%) and a minimum in January 1985 (16.31%). PMID:11935910

  6. Mitochondrial genome of the endangered marine gastropod Strombus gigas Linnaeus, 1758 (Mollusca: Gastropoda).

    PubMed

    M醨quez, Edna J; Castro, Erick R; Alzate, Juan F

    2014-09-01

    Abstract The queen conch Strombus gigas is an endangered marine gastropod of significant economic importance across the Greater Caribbean region. This work reports for the first time the complete mitochondrial genome of S. gigas, obtained by FLX 454 pyrosequencing. The mtDNA genome encodes for 13 proteins, 22 tRNAs and 2 ribosomal RNAs. In addition, the coding sequences and gene synteny were similar to other previously reported mitogenomes of gastropods. PMID:25186797

  7. Ultrastructural characteristics of typical and atypical spermatogenesis in the queen conch Strombus gigas (Mollusca, Gastropoda)

    Microsoft Academic Search

    NATHALIE CASSE; MARCEL LE PENNEC; ANG萀E HERRY; G蒖ARD SINQUIN; GERMAINE DORANGE

    1994-01-01

    As in many prosobranchs, two cell lines develop in the testis of Strombus gigas. The typical spermatogenesis is similar to that described in many species. The spermatic cell development is characterized by cell divisions. Typical spermatogenesis leads to a mature spermatozoa with a column-shaped nucleus. The acrosome consists of an acrosomal rod covered by an acrosomal cone and topped by

  8. Dynamics and ecology of an Indo-Pacific conch, Conomurex persicus (Mollusca: Gastropoda) in southeastern Turkey.

    PubMed

    Mutlu, Erhan; Ergev, Mehmet Betil

    2006-03-01

    Conomurex persicus, one of the tropical conchs, has been introduced to one of the subtropical regions, the northeastern Mediterranean Sea, and invaded sandy bottoms between 1 and 10 m deep. Population dynamics were studied from specimens collected with a standard dredge (60 x 15 cm mouth opening, 0.5 x 0.5 cm eye opening of net). Samples of C persicus were collected monthly along the 5 and 10 m depth contours off Erdemli, Mersin, Turkey, in February and May 2000. Intra-annual density depended on salinity levels, while inter-annual density was correlated with bottom water temperature. Specimens underwent spring emergences and winter burial and sheltering (disappearance). Emergence took place in March when temperatures rose and the disappearance occurred in October-November when temperatures dropped. Adults live at 10 m, juveniles are recruited at a 5 m depth. Recruitment began in April and continued for the next 6 months. In contrast to shell width or shell lip thickness, shell length was not a convenient index for estimation of growth parameters. Annual production and mortality were calculated to be 7.86 g m(-2) and 3.80 g m(-2), respectively, in April-November. PMID:18457181

  9. Ross Sea Mollusca from the Latitudinal Gradient Program: R/V Italica 2004 Rauschert dredge samples

    PubMed Central

    Ghiglione, Claudio; Alvaro, Maria Chiara; Griffiths, Huw J.; Linse, Katrin; Schiaparelli, Stefano

    2013-01-01

    Abstract Information regarding the molluscs in this dataset is based on the Rauschert dredge samples collected during the Latitudinal Gradient Program (LGP) on board the R/V 揑talica in the Ross Sea (Antarctica) in the austral summer 2004. A total of 18 epibenthic dredge deployments/samplings have been performed at four different locations at depths ranging from 84 to 515m by using a Rauschert dredge with a mesh size of 500?m. In total 8,359 specimens have been collected belonging to a total of 161 species. Considering this dataset in terms of occurrences, it corresponds to 505 discrete distributional records (incidence data). Of these, in order of abundance, 5,965 specimens were Gastropoda (accounting for 113 species), 1,323 were Bivalvia (accounting for 36 species), 949 were Aplacophora (accounting for 7 species), 74 specimens were Scaphopoda (3 species), 38 were Monoplacophora (1 species) and, finally, 10 specimens were Polyplacophora (1 species). This data set represents the first large-scale survey of benthic micro-molluscs for the area and provides important information about the distribution of several species, which have been seldom or never recorded before in the Ross Sea. All vouchers are permanently stored at the Italian National Antarctic Museum (MNA), Section of Genoa, enabling future comparison and crosschecking. This material is also currently under study, from a molecular point of view, by the barcoding project 揃AMBi (PNRA 2010/A1.10). PMID:24146597

  10. Bathymetric records of marine shelled mollusca from the northeastern shelf of Yucatan, Mexico

    E-print Network

    Treece, Granvil D

    1977-01-01

    Limopsis sp. ~LVFIIERIDAE ~dt t t ~ d t orbiculata 5 9 1 1 3 2 1 1 3 X X X 1 X 2 50 X X X 50 2 4 1 20 X 9a 9b St Sk Se Sg Si 9c 9d 9e 9f, 9g Glycimeris pectinatus Glvcimeris sericatus NYTILIDAE Crenella divaricate M~11 1 1... Codakia costata Codakia orbiculata Codakia sp. DL 1 11 p dd 1 Divaricella cf. eburnea ~LL ~L Lucina amiantus X 1 X X X X X 3 1 1 1 X 1 6 4 12 1 2 30 40 50 2 18 1 1 2 1 2 40 1 1 1 13 10 X X X X X X X X llc lid lie llf 12b 12c...

  11. Size-differential feeding in Pinna nobilis L. (Mollusca: Bivalvia): Exploitation of detritus, phytoplankton and zooplankton

    NASA Astrophysics Data System (ADS)

    Davenport, John; Ezgeta-Bali?, Daria; Peharda, Melita; Skeji?, Sanda; Nin?evi?-Gladan, 巌vana; Matijevi?, Slavica

    2011-04-01

    The endangered fan shell Pinna nobilis is a large bivalve mollusc (<120 cm shell length) endemic to the Mediterranean that lives one-third buried in soft substrata, generally in shallow coastal waters. We hypothesised that P. nobilis of different sizes would ingest different food sources, because small fan shells will inhale material from closer to the substratum than do large fan shells. We studied stomach contents and faeces of 18 fan shells, 6 small (mean 23.0 cm length), 6 medium-sized (mean 41.5 cm length) and 6 large (mean 62.7 cm length) living in a small area of a low-energy coastal detritic bottom characterised by mud, sand and macroalgae at Mali Ston Bay, Croatia. We found that all P. nobilis ingested copious quantities of undetermined detritus (probably at least 95% of ingested material), phytoplankton, micro and mesozooplankton and pollen grains. Large P. nobilis stomach contents showed a preponderance of water column calanoid copepods, while small fan shells had higher numbers of bivalve larvae. All fan shells took in high numbers of harpacticoid copepods that are benthonic, feeding on microbial communities of detritus and benthic vegetation. There was also a significant selection of phytoplankton species, some apparently occurring between inhalation and ingestion. The stomach contents of small P. nobilis had a higher organic matter content than either medium-sized or large fan shells; this indicated that small fan shells ingested detritus of higher organic content than did larger P. nobilis. As the faeces of all P. nobilis had similar organic matter content, this also indicates higher assimilation efficiencies in small fan shells. The demonstration of differential dietary selectivity by different sized animals has implications for future trophic studies of this endangered species. This study also provides the first demonstration of predation on zooplankton by P. nobilis.

  12. DNA barcoding reveals neritid diversity (Mollusca: Gastropoda) diversity in Malaysian waters.

    PubMed

    Chee, S Y; Mohd Nor, Siti Azizah

    2014-12-01

    Abstract This is the first study to identify and determine the phylogenetics of neritids found in Malaysia. In total, twelve species from the family Neritidae were recorded. Ten species were from the genus Nerita and two species were from the genus Neritina. DNA barcodes were successfully assigned to each species. Although some of these species were previously reported in the region, three are only presently reported in this study. The dendrogram showed Nerita and Neritina strongly supported in their respective monophyletic clades. Phylogenetic positions of some species appeared unstable in the trees. This could be due to the differences in a small number of nucleotides, thus minimizing genetic variation between each specimen and species. PMID:25471442

  13. The Pallial Organs in the Aspidobranch Gastropoda and their Evolution throughout the Mollusca

    Microsoft Academic Search

    C. M. Yonge

    1947-01-01

    The pallial organs and the currents within the mantle cavity have been studied in many genera of aspidobranch Gastropoda including members of the Zeugobranchia, Fissurellidae, Patellacea (Docoglossa), Trochacea, Neritacea and Valvatacea. Relevant data on allied genera, not available alive, have been considered. The aspidobranch condition has been retained in a diverse variety of Prosobranchia; its possession does not indicate close

  14. Informe Anual a la Naci髇 sobre el Estado del C醤cer, de 1975 a 2010, con una secci髇 especial sobre la prevalencia de comorbilidad y su efecto en la supervivencia de personas con c醤cer de pulm髇, seno, pr髎tata o colorrectal: preguntas y respuestas

    Cancer.gov

    El Informe Anual a la Naci髇 sobre el Estado del C醤cer (1975 a 2010), mostr un descenso m醩 acelerado que en a駉s anteriores de los 韓dices de mortalidad por c醤cer de pulm髇. Tambi閚 contiene una secci髇 especial que destaca los efectos significativos que tienen otras enfermedades en la supervivencia de pacientes con c醤cer.

  15. Los 韓dices de mortalidad por c醤cer de pulm髇 siguen bajando y contribuyen a reducci髇 de 韓dices generales de muertes por c醤cer; Informe Anual a la Naci髇 tiene una secci髇 especial de los efectos de otras enfermedades en la supervivencia de pacientes

    Cancer.gov

    El Informe Anual a la Naci髇 sobre el Estado del C醤cer (1975 a 2010), mostr un descenso m醩 acelerado que en a駉s anteriores de los 韓dices de mortalidad por c醤cer de pulm髇. Tambi閚 contiene una secci髇 especial que destaca los efectos significativos que tienen otras enfermedades en la supervivencia de pacientes con c醤cer.

  16. The idea of flooding in the desert metropolis of Phoenix may seem incongruous, especially when one considers that the average rainfall in the Phoenix area is less than eight inches a year. Yet, since the city was founded in 1867 its residents have had to

    E-print Network

    Hall, Sharon J.

    ABSTRACT The idea of flooding in the desert metropolis of Phoenix may seem incongruous, especially, since the city was founded in 1867 its residents have had to contend with periodic flooding. Particularly damaging have been floods on the Salt River, which runs through the middle of the Phoenix

  17. BiotecnologBiotecnologaa dede PlantasPlantas DesafDesafosos para lapara la expresiexpresinn de genesde genes introducidosintroducidos

    E-print Network

    M醠aga, Universidad de

    tejidostejidos GENGEN GENGEN DesarrollosBiotecnol骻icos GMOs - Organismos Geneticamente modificados GMO - Un Roundup El gen viene de Bacteria Wheat Rye Triticale X Cruce interespec韋ico Nueva especie, pero NO un

  18. Problem Based Learning, Especially in the Context of Large Classes

    NSDL National Science Digital Library

    This webpage from McMaster University in Canada describes one approach using small groups for using problem-based learning in teaching large classes. The focus of the authors is on teaching medical students but they also describe use of this approach in teaching civil engineering students, geography, etc. Links are provided to pdf files containing useful resources for instructors on being a good coach, assessment, and literature references to pbl.

  19. Graph analysis of dream reports is especially informative about psychosis.

    PubMed

    Mota, Nat醠ia B; Furtado, Raimundo; Maia, Pedro P C; Copelli, Mauro; Ribeiro, Sidarta

    2014-01-01

    Early psychiatry investigated dreams to understand psychopathologies. Contemporary psychiatry, which neglects dreams, has been criticized for lack of objectivity. In search of quantitative insight into the structure of psychotic speech, we investigated speech graph attributes (SGA) in patients with schizophrenia, bipolar disorder type I, and non-psychotic controls as they reported waking and dream contents. Schizophrenic subjects spoke with reduced connectivity, in tight correlation with negative and cognitive symptoms measured by standard psychometric scales. Bipolar and control subjects were undistinguishable by waking reports, but in dream reports bipolar subjects showed significantly less connectivity. Dream-related SGA outperformed psychometric scores or waking-related data for group sorting. Altogether, the results indicate that online and offline processing, the two most fundamental modes of brain operation, produce nearly opposite effects on recollections: While dreaming exposes differences in the mnemonic records across individuals, waking dampens distinctions. The results also demonstrate the feasibility of the differential diagnosis of psychosis based on the analysis of dream graphs, pointing to a fast, low-cost and language-invariant tool for psychiatric diagnosis and the objective search for biomarkers. The Freudian notion that "dreams are the royal road to the unconscious" is clinically useful, after all. PMID:24424108

  20. Immune Mechanisms in Atherosclerosis, Especially in Diabetes Type 2

    PubMed Central

    Frosteg錼d, Johan

    2013-01-01

    Atherosclerosis and ensuing cardiovascular disease (CVD) are major complications of diabetes type 2. Atherosclerosis is a chronic inflammatory condition involving immunocompetent cells of different types present in the lesions. Even though inflammation and immune activation may be more pronounced in atherosclerosis in diabetes type 2, there does not appear to be any major differences between diabetics and non-diabetics. Similar factors are thus implicated in atherosclerosis-associated immune activation in both groups. The cause of immune activation is not known and different mutually non-exclusive possibilities exist. Oxidized and/or enzymatically modified forms of low-density lipoprotein (OxLDL) and dead cells are present in atherosclerotic plaques. OxLDL could play a role, being pro-inflammatory and immunostimulatory as it activates T-cells and is cytotoxic at higher concentrations. Inflammatory phospholipids in OxLDL are implicated, with phosphorylcholine (PC) as one of the exposed antigens. Antibodies against PC (anti-PC) are anti-atherogenic in mouse studies, and anti-PC is negatively associated with development of atherosclerosis and CVD in humans. Bacteria and virus have been discussed as potential causes of immune activation, but it has been difficult to find direct evidence supporting this hypothesis, and antibiotic trials in humans have been negative or inconclusive. Heat shock proteins (HSP) could be one major target for atherogenic immune reactions. More direct causes of plaque rupture include cytokines such as interleukin 1? (IL-1?), tumor necrosis factor (TNF), and also lipid mediators as leukotrienes. In addition, in diabetes, hyperglycemia and oxidative stress appear to accelerate the development of atherosclerosis, one mechanism could be via promotion of immune reactions. To prove that immune reactions are causative of atherosclerosis and CVD, further studies with immune-modulatory treatments are needed. PMID:24194733

  1. Aviation fuels : with especial reference to "white spirit."

    NASA Technical Reports Server (NTRS)

    Dumanois, P

    1928-01-01

    Gasoline, the fuel now used, is an extremely volatile and inflammable liquid capable of forming explosive mixtures, the cause of many catastrophes in aviation. It is therefore of special interest to investigate the possibility of using fuels which, while being less volatile than gasoline, would nevertheless enable this engine to function satisfactorily.

  2. Designed Especially for Students of INJURY AND SICKNESS

    E-print Network

    Cui, Yan

    -TN (Rev 07-08) 2011-2012 University of Tennessee Health Science Center #12;Table of Contents Privacy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Benefits for Hearing Screening Tests for Newborn Infants

  3. Maximum Entropy for Hypothesis Formulation, Especially for Multidimensional Contingency Tables

    Microsoft Academic Search

    I. J. Good

    1963-01-01

    The principle of maximum entropy, together with some generalizations, is interpreted as a heuristic principle for the generation of null hypotheses. The main application is to $m$-dimensional population contingency tables, with the marginal totals given down to dimension $m - r$ (\\

  4. Graph analysis of dream reports is especially informative about psychosis

    PubMed Central

    Mota, Nat醠ia B.; Furtado, Raimundo; Maia, Pedro P. C.; Copelli, Mauro; Ribeiro, Sidarta

    2014-01-01

    Early psychiatry investigated dreams to understand psychopathologies. Contemporary psychiatry, which neglects dreams, has been criticized for lack of objectivity. In search of quantitative insight into the structure of psychotic speech, we investigated speech graph attributes (SGA) in patients with schizophrenia, bipolar disorder type I, and non-psychotic controls as they reported waking and dream contents. Schizophrenic subjects spoke with reduced connectivity, in tight correlation with negative and cognitive symptoms measured by standard psychometric scales. Bipolar and control subjects were undistinguishable by waking reports, but in dream reports bipolar subjects showed significantly less connectivity. Dream-related SGA outperformed psychometric scores or waking-related data for group sorting. Altogether, the results indicate that online and offline processing, the two most fundamental modes of brain operation, produce nearly opposite effects on recollections: While dreaming exposes differences in the mnemonic records across individuals, waking dampens distinctions. The results also demonstrate the feasibility of the differential diagnosis of psychosis based on the analysis of dream graphs, pointing to a fast, low-cost and language-invariant tool for psychiatric diagnosis and the objective search for biomarkers. The Freudian notion that 揹reams are the royal road to the unconscious is clinically useful, after all. PMID:24424108

  5. Apparatus and method for cutting soft materials, especially meat

    DOEpatents

    Spletzer, Barry L.; Callow, Diane S.; Jones, James F.; Kuehl, Michael A.; Shaw, Dick L.; Scalia, Barbara J.

    2005-10-18

    An apparatus and method for cutting soft materials such as meat. Two or more spirally mounted helical blades are situated between two supports, and the supports are mounted to a shank. The shank is rotated to impart rotary action to the spiral shear blades, and the entire device may be used to perform various cutting operations. The distal or bottom one of the supports may also be a cutting blade, and a number of versions of bottom cutting blades are useable in the practice of the invention.

  6. Necrotizing Fasciitis: A Rare Disease, Especially for the Healthy

    MedlinePLUS

    ... Stages & Populations Travelers' Health Workplace Safety & Health Features Media Sign up for Features Get Email Updates To ... infections does not appear to be rising. Features Media Sign up for Features Get Email Updates To ...

  7. Especial Skills: Their Emergence With Massive Amounts of Practice

    Microsoft Academic Search

    Katherine M. Keetch; Richard A. Schmidt; Timothy D. Lee; Douglas E. Young

    2005-01-01

    Differing viewpoints concerning the specificity and generality of motor skill representations in memory were compared by contrasting versions of a skill having either extensive or minimal specific practice. In Experiments 1 and 2, skilled basketball players more accurately performed set shots at the foul line than would be predicted on the basis of the performance at the nearby locations, suggesting

  8. Especially Designed for Students, Scholars and Faculty Studying Abroad

    E-print Network

    Sekelsky, Jeff

    of the Participating Schools of the 2009-2010 Study Abroad Blanket Student Accident and Sickness Insurance UNIVERSITY of student accident and sickness insurance underwritten by the UniCare Life & Health Insurance Company.610.254.8780 hthstudents.com studentinfo@hthworldwide.com Insurance Underwritten by: This blanket accident and sickness

  9. Factors influencing the supercooling of tropical Arthropoda, especially locusts

    Microsoft Academic Search

    J. L. Cloudsley-Thompson

    1973-01-01

    Mean supercooling points are given for a number of tropical arthropods (table 1). These are surprisingly low in view of the fact that, in many cases, the animals never experience frost in nature, and it is argued that the ability to supercool may be a taxonomic rather than an adaptive feature. Beetles (Ocnera hispida) and desert locusts (Schistocerca gregaria) that

  10. Especies Anillo: Demonstraciones Inusuales de Especiaci贸n

    NSDL National Science Digital Library

    Darren Irwin (Lund University, Sweden; )

    2009-09-09

    Ring species provide a unique glimpse into how some species came to be. A ring of populations encircles an area of unsuitable habitat. At one location in the ring, two distinct forms coexist without interbreeding. Around the rest of the ring, the traits of one species change gradually through intermediate populations into the second species?? traits.

  11. A Look at Four Encyclopedias of 1974--Especially Britannica.

    ERIC Educational Resources Information Center

    Youngstown and Mahoning County Public Library, Youngstown, OH.

    In a panel presentation, Americana, Colliers, Britannica, and World Book encyclopedias were compared. One member described her daughter's experiences in working on Britannica II. The organization of Britannica into a Propaedia, Micropaedia, and a Macropaedia was compared with the alphabetical arrangement of the others. The complex new form was

  12. LOS 覴DENES DE LA VIOLENCIA: ESPECIE, SEXO Y G蒒ERO 1

    Microsoft Academic Search

    MAR虯 JES赟 IZQUIERDO

    1998-01-01

    En la actualidad estamos asistiendo a un ejercicio de ingenier韆 social consistente en presentar, como un hecho, como conocimiento de sentido com鷑, la contrapos ici髇 violentos\\/dem骳ratas. Se considera incuestionable que violencia y democracia forman una antinomia, dos formas de abordar las cuestiones pol韙icas opuestas y mutu amente excluyentes. Un trabajo paralelo es el que se est haciendo en relaci髇 a

  13. Graph analysis of dream reports is especially informative about psychosis

    NASA Astrophysics Data System (ADS)

    Mota, Nat醠ia B.; Furtado, Raimundo; Maia, Pedro P. C.; Copelli, Mauro; Ribeiro, Sidarta

    2014-01-01

    Early psychiatry investigated dreams to understand psychopathologies. Contemporary psychiatry, which neglects dreams, has been criticized for lack of objectivity. In search of quantitative insight into the structure of psychotic speech, we investigated speech graph attributes (SGA) in patients with schizophrenia, bipolar disorder type I, and non-psychotic controls as they reported waking and dream contents. Schizophrenic subjects spoke with reduced connectivity, in tight correlation with negative and cognitive symptoms measured by standard psychometric scales. Bipolar and control subjects were undistinguishable by waking reports, but in dream reports bipolar subjects showed significantly less connectivity. Dream-related SGA outperformed psychometric scores or waking-related data for group sorting. Altogether, the results indicate that online and offline processing, the two most fundamental modes of brain operation, produce nearly opposite effects on recollections: While dreaming exposes differences in the mnemonic records across individuals, waking dampens distinctions. The results also demonstrate the feasibility of the differential diagnosis of psychosis based on the analysis of dream graphs, pointing to a fast, low-cost and language-invariant tool for psychiatric diagnosis and the objective search for biomarkers. The Freudian notion that ``dreams are the royal road to the unconscious'' is clinically useful, after all.

  14. EL RADIOSEGUIMIENTO EN ESPECIES AMENAZADAS: EL CASO DE LA AVUTARDA

    Microsoft Academic Search

    Juan C. Alonso; Javier A. Alonso; Carlos A. Mart韓; Carlos Palac韓; Marina Maga馻

    Desde hace m醩 de diez a駉s nuestro equipo viene desarrollando un amplio proyec- to de investigaci髇 sobre la biolog韆 de la avutarda en Espa馻, en el que el marcaje individual con placas alares y emisores de radio ha sido el m閠odo de estudio funda- mental. Hasta la fecha se han marcado en diferentes poblaciones espa駉las m醩 de 500 avutardas, unas

  15. Abstract Wireless indoor localization systems and especially signal strength

    E-print Network

    with current sensor values, and finally inertial navigation, which relies on motion sensors to derive to match the current sensor readings with a previously recorded location. Without this information the current location. For indoor localization, scene-analysis have been deemed a promising approach since most

  16. Designed Especially for Students of INJURY AND SICKNESS

    E-print Network

    Subramanian, Venkat

    limits ensure that consumers have sufficient access to medical benefits throughout the annual term . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Schedule of Medical Expense Benefits

  17. Water is Vital--Especially after a Disaster

    E-print Network

    Crocker, Andrew

    2005-10-10

    Dehydration can be a serious threat after a disaster, when supplies of clean drinking water may be limited. Learn how you can find and use hidden sources of water in your home and purify water to make it safe for drinking....

  18. Consciousness: a neural capacity for objectivity, especially pronounced in humans

    PubMed Central

    Dijker, Anton J. M.

    2014-01-01

    Consciousness tends to be viewed either as subjective experience of sensations and feelings, or as perception and internal representation of objects. This paper argues that neither view sufficiently acknowledges that consciousness may refer to the brain抯 most adaptive property: its capacity to produce states of objectivity. It is proposed that this capacity relies on multiple sensorimotor networks for internally representing objects and their properties in terms of expectancies, as well as on motivational and motor mechanisms involved in exploration, play, and care for vulnerable living and non-living objects. States of objectivity are associated with a very special phenomenal aspect; the experience that subjective aspects are absent and one is 搄ust looking at the world as it really is and can be. However, these states are normally closely preceded and followed by (and tend to be combined or fused with) sensations and feelings which are caused by activation of sensory and motivational mechanisms. A capacity for objectivity may have evolved in different species and can be conceived as a common basis for other elusive psychological properties such as intelligence, conscience, and esthetic experience; all three linked to crucial behaviors in human evolution such as tool making, cooperation, and art. The brain抯 pervasive tendency to objectify may be responsible for wrongly equating consciousness with feelings and wrongly opposing it to well-learned or habitual (搖nconscious) patterns of perception and behavior. PMID:24672506

  19. Playing Together Beats Playing Apart, Especially for Girls

    Microsoft Academic Search

    Kori Inkpen; Kellogg S. Booth; Maria Klawe; Rena Upitis

    1995-01-01

    This paper describes follow-on studies focusing on how gender and grouping affects performance and attitudes of children playing a puzzle solving game called The Incredible Machine (TIM). We found that children playing together on one machine solved significantly more puzzles than children playing alone on one machine. Female\\/Female pairs playing together on one machine, on average, completed significantly more puzzles

  20. Geometrical system calibration, especially for metric aerial cameras

    Microsoft Academic Search

    G. Kupfer

    1986-01-01

    Geometrical system calibration is defined and its history is reviewed. Practical considerations and desirable capabilities of a calibration algorithm are discussed. Problems of full and partial system calibration are shown and recommendations for geometrical system calibration are given. Possibilities of the procedure are shown by examples.

  1. Ciudad Universitaria 07 de mayo de 2009 II SUPLEMENTO ESPECIAL

    E-print Network

    Islas, Le髇

    instal un Comit Universitario para Atender la Emergencia Sanita- ria, responsable de informar de las labores en los niveles medio superior y superior, la UNAM decidi que las actividades de su bachillerato.................................................III Comit Universitario para Atender la Emergencia Sanitaria

  2. Progress Lags in High School, Especially for Advanced Achievers

    ERIC Educational Resources Information Center

    Education Digest: Essential Readings Condensed for Quick Review, 2012

    2012-01-01

    This report by the Center on Education Policy (CEP), an independent nonprofit organization, examines trends in the achievement of high school students on the state reading/English language arts (ELA) and mathematics tests used for accountability under the No Child Left Behind Act (NCLB). This study confirms that there is reason for concern about

  3. Especial Skills: Their Emergence with Massive Amounts of Practice

    ERIC Educational Resources Information Center

    Keetch, Katherine M.; Schmidt, Richard A.; Lee, Timothy D.; Young, Douglas E.

    2005-01-01

    Differing viewpoints concerning the specificity and generality of motor skill representations in memory were compared by contrasting versions of a skill having either extensive or minimal specific practice. In Experiments 1 and 2, skilled basketball players more accurately performed set shots at the foul line than would be predicted on the basis

  4. ORIGINAL PAPER Population genetic analysis of Ensis directus unveils high genetic

    E-print Network

    Fuentes, Marcelino

    of the razor shell Ensis directus (Conrad 1843) (Mollusca: Bivalvia: Pharidae) in native (North American directus (Conrad 1843) syn. E. americanus (Binney, in Gould and Binney 1870) (Mollusca: Bivalvia: Pharidae

  5. Polar Biology ISSN 0722-4060

    E-print Network

    00300-010-0889-6 A new species of Armodoris (Mollusca, Gastropoda, Nudibranchia, Akiodorididae) from Mc NOTE A new species of Armodoris (Mollusca, Gastropoda, Nudibranchia, Akiodorididae) from McMurdo Sound

  6. Naturwissenschaften (2005) 92: 504515 DOI 10.1007/s00114-005-0045-2

    E-print Network

    Davison, Angus

    / Published online: 11 October 2005 # Springer-Verlag 2005 Abstract The direction that a snail (Mollusca (Trichop- tera). The organisms best known for their coiled form, however, are probably the Mollusca

  7. Journal of species lists and distribution NotesoNGeoGraphicDistributioN

    E-print Network

    Floeter, Sergio Ricardo

    southward. 1 Zoologische Staatssammlung M眉nchen, Mollusca Sektion, M眉nchhausenstr. 21, 81247, M眉nchen and Alberto Lindner3 Mollusca, Nudibranchia: New records and southward range extensions in Santa Catarina

  8. letters to nature NATURE |VOL 410 |22 MARCH 2001 |www.nature.com 463

    E-print Network

    Bolnick, Daniel I.

    卤358 (1995). 3. Ivanov, D. L. in Origin and Evolutionary Radiation of the Mollusca (ed. Taylor, J. D.) 59卤65 (Oxford Univ. Press, 1996). 4. Lindberg, D. R. in Origin and Evolutionary Radiation of the Mollusca (ed. Rosenberg, G. et al. Ribosomal RNA phylogeny of selected major clades in the Mollusca. J. Mollus. Stud. 63

  9. JMBA Global Marine Environment 23 Horse mussel (Modiolus modiolus) reef seen obliquely using interpreted multibeam data

    E-print Network

    Watson, Andrew

    modiolus (Mollusca: Bivalvia) reef in the Irish Sea: I. Seabed mapping and reef morphology. JMBA, 88, 133-scale variation within a Modiolus modiolus (Mollusca: Bivalvia) reef in the Irish Sea. II. Epifauna recorded. Small-scale variation within a Modiolus modiolus (Mollusca: Bivalvia) reef in the Irish Sea. III

  10. Evolutionary pattern and process within the Vertigo gouldii (Mollusca: Pulmonata, Pupillidae) group of minute North American land snails

    E-print Network

    Bergthorsson, Ulfar

    .77.0 myBP, which would be co-incident with known mid-late Miocene global climate changes. 2009 Elsevier Section, Department of Biodiversity, National Museum of Wales, Cathays Park, Cardiff CF10 3NP, UK a r t i fauna (Pils- bry, 1948). This community fragmented following climatic cooling and drying from

  11. Ecotoxicological studies with newly hatched larvae of Concholepas concholepas (Mollusca, Gastropoda): bioassay with secondary-treated kraft pulp mill effluents.

    PubMed

    Manr韖uez, Patricio H; Llanos-Rivera, Alejandra; Galaz, Sylvana; Cama駉, Andr閟

    2013-12-01

    The Chilean abalone or "loco" (Concholepas concholepas, Brugui鑢e 1789) represent the most economically important marine recourse exploited from inner inshore Management and Exploitation Areas for Benthic Resources along the Chilean coast. In this study, newly-hatched larvae of C. concholepas were investigated as a potential model species for marine ecotoxicological studies. The study developed a behavioral standard protocol for assessing the impact that kraft pulp mill effluents after secondary treatment have on C. concholepas larvae. Under controlled laboratory conditions, newly-hatched larvae were exposed to a series of different concentrations of kraft pulp mill effluents with secondary treatment (Pinus spp. and Eucalyptus spp.), potassium dichromate as standard reference toxicant and effluent-free control conditions. Regardless of the type of effluent the results indicated that diluted kraft pulp effluent with secondary treatment had reduced effect on larval survival. Low larval survivals were only recorded when they were exposed to high concentrations of the reference toxicant. This suggests that C. concholepas larval bioassay is a simple method for monitoring the effects of kraft pulp mill effluents with secondary treatment discharged into the sea. The results indicated that dilution of ca. 1% of the effluent with an elemental chlorine free (ECF) secondary treatment is appropriate for achieving low larval mortalities, such as those obtained under control conditions with filtered seawater, and to minimize their impact on early ontogenetic stages of marine invertebrates such as newly-hatched larvae of C. concholepas. The methodological aspects of toxicological testing and behavioral responses described here with newly-hatched larvae of C. concholepas can be used to evaluate in the future the potential effects of other stressful conditions as other pollutants or changes in seawater pH associated with ocean acidification. PMID:24099753

  12. Natural infection of deroceras laeve (Mollusca: gastropoda) with metastronbylid larvae in a transmission focus of abdominal angiostrongyliasis.

    PubMed

    Maurer, Rafael Lucyk; Graeff-Teixeira, Carlos; Thome, Jos Willibaldo; Chiaradia, Lu韘 Ant鬾io; Sugaya, Hiroko; Yoshimura, Kentaro

    2002-01-01

    Angiostrongylus costaricensis is a nematode parasitic of rodents. Man may become infected by ingestion of the third stage larvae produced within the intermediate hosts, usually slugs from the family Veronicellidae. An epidemiological study carried out in a locality in southern Brazil (western Santa Catarina State) where these slugs are a crop pest and an important vector for A. costaricensis has documented for the first time the natural infection of Deroceras laeve with metastrongylid larvae. This small limacid slug is frequently found amid the folds of vegetable leaves and may be inadvertently ingested. Therefore D. laeve may have an important role in transmission of A. costaricensis to man. PMID:11896413

  13. Susceptibility of North American Native and Non-native Slugs (Mollusca: Gastropoda) to Phasmarhabditis hermaphrodita (Nematoda: Rhabditidae)

    Microsoft Academic Search

    Sukhbir K. Grewal; Parwinder S. Grewal; Ronald B. Hammond

    2003-01-01

    Phasmarhabditis hermaphrodita caused significant mortality of the two native species, Deroceras laeve and Leidyula floridana, and of one introduced species D. reticulatum, but not of the other three introduced species, Arion hortensis, A. subfuscus and Limax maximus. Even the juvenile stages of A. subfuscus and L. maximus showed no mortality in nematode treatments. However, treatments with nematodes resulted in rapid

  14. A new genus and species of Thyasiridae (Mollusca, Bivalvia) from deep-water, Beaufort Sea, northern Alaska

    PubMed Central

    Valentich-Scott, Paul; Powell, Charles L.; II; Lorenson, Thomas D.; Edwards, Brian E.

    2014-01-01

    Abstract Bivalve mollusk shells were collected in 2350 m depth in the Beaufort Sea, Arctic Ocean off northern Alaska. Initial identification suggested the specimens were a member of the bivalve family Thyasiridae, but no known eastern Pacific or Arctic living or fossil thyasirid resembled these deep-water specimens. Comparisons were made with the type of the genera Maorithyas Fleming, 1950, Spinaxinus Oliver & Holmes, 2006, Axinus Sowerby, 1821, and Parathyasira Iredale, 1930. We determined the Beaufort Sea species represents a new genus, herein described as Wallerconcha. These specimens also represent a new species, herein named Wallerconcha sarae. These new taxa are compared with known modern and fossil genera and species of thyasirds. PMID:25589851

  15. Evolutionary Pattern and Process within the Vertigo gouldii (Mollusca: Pulmonata, Pupillidae) group of minute North American Land Snails

    PubMed Central

    Nekola, Jeffrey C.; Coles, Brian F.; Bergthorsson, Ulfar

    2010-01-01

    A phylogenetic analysis of 19 sibling taxa in the Vertigo gouldii group was conducted on 73 individuals sampled across North America using DNA sequence data of the mitochondrial genes cytochrome oxidase subunit 1 (CO1) and 16S ribosomal RNA (16S), and the internal transcribed spacer-2 of the nuclear ribosomal RNA (ITS-2) gene. The results of these analyses were found incongruent with previous taxonomic concepts used to define the V. gouldii group and its composite taxa that were based entirely on conchological features. The mtDNA sequence data suggest that some previous members of the traditional V. gouldii group may be more closely related to V. modesta. They also suggest that V. gouldii may itself consist of seven species-level branches spread across two deeply rooted clades. Revision of geographical distributions on the basis of these analyses suggests that these Vertigo species may commonly possess continental-sized ranges in spite of their minute size and limited active dispersal ability. High levels of sympatry within the group are also confirmed, with up to four species being known to co-occur within single microsites. These data also suggest that rates of diversification have been non-constant. Assuming a 1%/my rate of base pair substitution, a 10-fold diversification pulse is indicated from 6.7-7.0 myBP, which would be co-incident with known mid-late Miocene global climate changes. PMID:19766197

  16. Developmental toxicity, acute toxicity and mutagenicity testing in freshwater snails Biomphalaria glabrata (Mollusca: Gastropoda) exposed to chromium and water samples.

    PubMed

    Tallarico, Lenita de Freitas; Borrely, Sueli Ivone; Hamada, Nat醠ia; Grazeffe, Vanessa Siqueira; Ohlweiler, Fernanda Pires; Okazaki, Kayo; Granatelli, Amanda Tosatte; Pereira, Ivana Wuo; Pereira, Carlos Alberto de Bragan鏰; Nakano, Eliana

    2014-12-01

    A protocol combining acute toxicity, developmental toxicity and mutagenicity analysis in freshwater snail Biomphalaria glabrata for application in ecotoxicological studies is described. For acute toxicity testing, LC50 and EC50 values were determined; dominant lethal mutations induction was the endpoint for mutagenicity analysis. Reference toxicant potassium dichromate (K2Cr2O7) was used to characterize B. glabrata sensitivity for toxicity and cyclophosphamide to mutagenicity testing purposes. Compared to other relevant freshwater species, B. glabrata showed high sensitivity: the lowest EC50 value was obtained with embryos at veliger stage (5.76mg/L). To assess the model applicability for environmental studies, influent and effluent water samples from a wastewater treatment plant were evaluated. Gastropod sensitivity was assessed in comparison to the standardized bioassay with Daphnia similis exposed to the same water samples. Sampling sites identified as toxic to daphnids were also detected by snails, showing a qualitatively similar sensitivity suggesting that B. glabrata is a suitable test species for freshwater monitoring. Holding procedures and protocols implemented for toxicity and developmental bioassays showed to be in compliance with international standards for intra-laboratory precision. Thereby, we are proposing this system for application in ecotoxicological studies. PMID:25259848

  17. Living on the mountains: patterns and causes of diversification in the springsnail subgenus Pseudamnicola (Corrosella) (Mollusca: Caenogastropoda: Hydrobiidae).

    PubMed

    Delicado, Diana; Machordom, Annie; Ramos, Marian A

    2013-09-01

    Hydrobiidae is one of the largest families of freshwater gastropods comprised of approximately 400 genera and 1000 species. Despite this high level of diversity, most hydrobiid species inhabit fragile ecosystems in restricted distribution areas. In this work, we analyze modes of speciation and causes of diversification in the hydrobiid springsnail subgenus Pseudamnicola (Corrosella). Species of this group typically live in nutrient poor springs and streams and are restricted to mountainous regions of the Iberian Peninsula (Spain) and Southern France. Previous morphological and molecular (based only on the cytochrome c oxidase subunit I (COI) gene) studies revealed 11 nominal Corrosella species. In this study, we enhance published molecular results by generating new data from mitochondrial (16S rRNA and COI) and nuclear ribosomal regions (18S and 28S rRNA) from 50 Corrosella populations. As a result of this study we have identified one new species, making a total of twelve recognized species in the subgenus Corrosella. Our phylogenetic results also reveal the existence of three lineages within the subgenus, and the estimation of time divergence indicates the occurrence of three main speciation events during the upper Miocene to Pleistocene. We test the influence of several geographical and ecological variables and observe that diversification patterns are related to habitat fragmentation rather than environmental conditions. This result suggests that the high level of diversity observed within the subgenus may have resulted from a non-adaptive radiation. The formation of the Iberian Peninsula mountain ranges (the Pyrenees in the north and the Betic Cordillera in the south) and the configuration of the Iberian current hydrographic system played important roles in Corrosella speciation. Additionally, during the Miocene the Iberian Peninsula experienced a gradient of increasing temperature and dryness from north to south, which together with a high level of tectonic activity, may have caused the majority of the diversity found in the southern Iberian Peninsula. PMID:23660110

  18. Opisthobranchia (Mollusca, Gastropoda) more than just slimy slugs. Shell reduction and its implications on defence and foraging

    PubMed Central

    W鋑ele, Heike; Klussmann-Kolb, Annette

    2005-01-01

    Background In general shell-less slugs are considered to be slimy animals with a rather dull appearance and a pest to garden plants. But marine slugs usually are beautifully coloured animals belonging to the less-known Opisthobranchia. They are characterized by a large array of interesting biological phenomena, usually related to foraging and/or defence. In this paper our knowledge of shell reduction, correlated with the evolution of different defensive and foraging strategies is reviewed, and new results on histology of different glandular systems are included. Results Based on a phylogeny obtained by morphological and histological data, the parallel reduction of the shell within the different groups is outlined. Major food sources are given and glandular structures are described as possible defensive structures in the external epithelia, and as internal glands. Conclusion According to phylogenetic analyses, the reduction of the shell correlates with the evolution of defensive strategies. Many different kinds of defence structures, like cleptocnides, mantle dermal formations (MDFs), and acid glands, are only present in shell-less slugs. In several cases, it is not clear whether the defensive devices were a prerequisite for the reduction of the shell, or reduction occurred before. Reduction of the shell and acquisition of different defensive structures had an implication on exploration of new food sources and therefore likely enhanced adaptive radiation of several groups. PMID:15715915

  19. First record of a nematode Metastrongyloidea (Aelurostrongylus abstrusus larvae) in Achatina (Lissachatina) fulica (Mollusca, Achatinidae) in Brazil.

    PubMed

    Thiengo, Silvana C; Fernandez, Monica A; Torres, Eduardo J L; Coelho, Pablo M; Lanfredi, Reinalda M

    2008-05-01

    Achatina (Lissachatina) fulica was introduced in Brazil in the 1980s for commercial purposes ("escargot" farming) and nowadays, mainly by human activity, it is widespread in at least 23 out of 26 Brazilian states and Bras韑ia, including the Amazonian region and natural reserves, where besides a general nuisance for people it is a pest and also a public health concern, since it is one of the natural intermediate host of Angiostrongylus cantonensis, ethiological agent of the meningoencephalitis in Asia. As Brazil is experiencing the explosive phase of the invasion, the Laborat髍io de Malacologia do Instituto Oswaldo Cruz/Fiocruz has been receiving samples of these molluscs for identification and search for Angiostrongylus cantonensis and Angiostrongylus costaricensis larvae. While examining samples of A. fulica different nematode larvae were obtained, including Aelurostrongylus, whose different species are parasites of felids, dogs, primates, and badger. Morphological and morphometric analyses presented herein indicated the species Aelurostrongylus abstrusus, as well as the occurrence of other nematode larvae (Strongyluris-like) found in the interior of the pallial cavity of A. fulica. This is the first report in Brazil of the development of A. abstrusus infective larvae in A. fulica evidencing the veterinary importance of this mollusc in the transmission of A. abstrusus to domestic cats. Since the spread of A. fulica is pointed out in the literature as one of the main causative spread of the meningoencephalitis caused by A. cantonensis the authors emphasize the need of sanitary vigilance of snails and rats from vulnerable areas for A. cantonensis introduction as the port side areas. PMID:18078952

  20. Short Communication Rebuilding viable spawner patches of the overfished Spisula solida (Mollusca: Bivalvia): a preliminary contribution to fishery sustainability

    Microsoft Academic Search

    Sandra Joaquim; Miguel B. Gaspar; Domitilia Matias; Radhouan Ben-Hamadou; William S. Arnold

    tioned into two groups (undersize and legal clams) and transplanted at a density of 40 clams m22 into two areas 50 m2. Transplanted and control clams were sampled to estimate survival, condition index, biochemical composition, and reproductive condition. Generally, the physiological condition of clams was not affected by the method of transplanting. One year after transplanting, survival was 45%. The

  1. Electrophoretic heterogeneity within and between flat periwinkles (Mollusca: Gastropoda) along an intertidal transect at Ria Ferrol, northwest Spain

    Microsoft Academic Search

    C. Olabarria; J.-M. Timmermans; T. Backeljau

    1998-01-01

    Using isoelectric focusing of esterases (EST), general proteins (GP) and myoglobin (Mb), we surveyed intra- and interspecific differentiation in flat periwinkles along a vertical intertidal transect in the Ensenada do Ba駉 at Ria Ferrol, N.W. Spain. In this region, L. obtusata occurs in four algal belts, although it is rare in the lowest zone defined by Fucus serratus. L. fabalis

  2. Congruence between allozyme and RAPD data in assessing macrogeographical genetic variation in the periwinkle Littorina striata (Mollusca, Gastropoda)

    Microsoft Academic Search

    H de Wolf; T Backeljau; R Verhagen

    1998-01-01

    The population genetic structure of the Macaronesian planktonic-developing periwinkle Littorina striata was analysed, using random amplified polymorphic DNA analysis (RAPD). Two primers, yielding six polymorphic loci, were surveyed to infer the population genetic structure of five geographically separated populations (i.e. 102000 km). Biased and unbiased allele frequency and heterozygosity levels were estimated and were found to be highly similar. As

  3. Annotated type catalogue of the Bothriembryontidae and Odontostomidae (Mollusca, Gastropoda, Orthalicoidea) in the Natural History Museum, London.

    PubMed

    Breure, Abraham S H; Ablett, Jonathan D

    2012-01-01

    The type status is described for specimens of 84 taxa classified within the families Bothriembryontidae and Odontostomidae (superfamily Orthalicoidea) and kept in the Natural History Museum, London. Lectotypes are designated for Bulimus (Liparus) brazieri Angas, 1871; Bulimus broderipii Sowerby I, 1832; Bulimus fuligineus Pfeiffer, 1853; Helix guarani d'Orbigny, 1835; Bulimus (Tomigerus) ramagei E.A. Smith, 1890; Helix rhodinostoma d'Orbigny, 1835; Bulimus (Bulimulus) ridleyi E.A. Smith, 1890. The type status of the following taxa is changed to lectotype in accordance with Art. 74.6 ICZN: Placostylus (Euplacostylus) cylindricus Fulton, 1907; Bulimus pyrostomus Pfeiffer, 1860; Bulimus turneri Pfeiffer, 1860. The following taxon is synonymised: Bulimus oblitus Reeve, 1848 = Bahiensis neglectus (Pfeiffer, 1847). PMID:22539914

  4. Cytogenetic characterisation of the razor shells Ensis directus (Conrad, 1843) and E. minor (Chenu, 1843) (Mollusca: Bivalvia)

    NASA Astrophysics Data System (ADS)

    Gonz醠ez-Tiz髇, Ana M.; Rojo, Ver髇ica; Vierna, Joaqu韓; Jensen, K. Thomas; Egea, Emilie; Mart韓ez-Lage, Andr閟

    2013-03-01

    The European razor shell Ensis minor (Chenu 1843) and the American E. directus (Conrad 1843) have a diploid chromosome number of 38 and remarkable differences in their karyotypes: E. minor has four metacentric, one metacentric-submetacentric, five submetacentric, one subtelocentric and eight telocentric chromosome pairs, whereas E. directus has three metacentric, two metacentric-submetacentric, six submetacentric, six subtelocentric and two telocentric pairs. Fluorescent in situ hybridisation (FISH) using a major ribosomal DNA probe located the major ribosomal genes on one submetacentric chromosome pair in both species; FISH with a 5S ribosomal DNA (5S rDNA) probe rendered one chromosomal (weak) signal for E. minor and no signal for E. directus, supporting a more dispersed organisation of 5S rDNA compared to the major ribosomal genes. The vertebrate telomeric sequence (TTAGGG) n was located on both ends of each chromosome, and no interstitial signals were detected. In this work, a comparative karyological analysis was also performed between the four Ensis species analysed revealing that the three European species studied so far, namely E. minor, E. siliqua (Linn 1758) and E. magnus Schumacher 1817 show more similarities among them than compared to the American species E. directus. In addition, clear karyotype differences were found between the morphologically similar species E. minor and E. siliqua.

  5. Phylogenetic relationships of mid-oceanic ridge and continental lineages of Lasaea spp. (Mollusca: Bivalvia) in the northeastern Atlantic

    Microsoft Academic Search

    Diarmaid Foighil; Robert Jennings; Joong-Ki Park; D. Andrew Merriwether

    2001-01-01

    Direct-developing lineages of the genus Lasaea are common constituents of both oceanic island and continental rocky shore crevice faunas in the eastern North Atlantic. We utilized mitochondrial gene sequence variation to flesh out the phylogenetic relationships of individuals sam- pled from 2 Macaronesian archipelagos (Azores, Madeira) and from downstream continental (Iber- ian) sites. There was no evidence for colonization of

  6. Polyplacophora (Mollusca) from the San Diego Formation: A remarkable assemblage of fossil chitons from the Pliocene of southern Califoria

    USGS Publications Warehouse

    Vendrasco, Michael J.; Eernisse, Douglas J.; Powell, Charles L.; Fernandez, Christine Z.

    2012-01-01

    taphonomic factors bias valve ratios long after valves are disarticulated. New foraminiferan and molluscan data indicate a middle or late Pliocene age of deposition for these beds, between 3.3 to 2.5 million years ago (Ma), and possibly about 3.0 Ma.

  7. Annotated type catalogue of the Megaspiridae, Orthalicidae, and Simpulopsidae (Mollusca, Gastropoda, Orthalicoidea) in the Natural History Museum, London

    PubMed Central

    Breure, Abraham S. H.; Ablett, Jonathan D.

    2015-01-01

    Abstract The type status is described for 65 taxa of the Orthalicoidea, classified within the families Megaspiridae (14), Orthalicidae (30), and Simpulopsidae (20); one taxon is considered a nomen inquirendum. Lectotypes are designated for the following taxa: Helix brephoides d扥rbigny, 1835; Simpulopsis cumingi Pfeiffer, 1861; Bulimulus (Protoglyptus) dejectus Fulton, 1907; Bulimus iris Pfeiffer, 1853. The type status of Bulimus salteri Sowerby III, 1890, and Strophocheilus (Eurytus) subirroratus da Costa, 1898 is now changed to lectotype according Art. 74.6 ICZN. The taxa Bulimus loxostomus Pfeiffer, 1853, Bulimus marmatensis Pfeiffer, 1855, Bulimus meobambensis Pfeiffer, 1855, and Orthalicus powissianus var. niveus Preston 1909 are now figured for the first time. The following taxa are now considered junior subjective synonyms: Bulimus marmatensis Pfeiffer, 1855 = Helix (Cochlogena) citrinovitrea Moricand, 1836; Vermiculatus Breure, 1978 = Bocourtia Rochebrune, 1882. New combinations are: Kuschelenia (Bocourtia) Rochebrune, 1882; Kuschelenia (Bocourtia) aequatoria (Pfeiffer, 1853); Kuschelenia (Bocourtia) anthisanensis (Pfeiffer, 1853); Kuschelenia (Bocourtia) aquila (Reeve, 1848); Kuschelenia (Bocourtia) badia (Sowerby I, 1835); Kuschelenia (Bocourtia) bicolor (Sowerby I, 1835); Kuschelenia (Bocourtia) caliginosa (Reeve, 1849); Kuschelenia (Bocourtia) coagulata (Reeve, 1849); Kuschelenia (Bocourtia) cotopaxiensis (Pfeiffer, 1853); Kuschelenia (Bocourtia) filaris (Pfeiffer, 1853); Kara indentata (da Costa, 1901); Clathrorthalicus magnificus (Pfeiffer, 1848); Simpulopsis (Eudioptus) marmartensis (Pfeiffer, 1855); Kuschelenia (Bocourtia) nucina (Reeve, 1850); Kuschelenia (Bocourtia) ochracea (Morelet, 1863); Kuschelenia (Bocourtia) peaki (Breure, 1978); Kuschelenia (Bocourtia) petiti (Pfeiffer, 1846); Clathrorthalicus phoebus (Pfeiffer, 1863); Kuschelenia (Bocourtia) polymorpha (d扥rbigny, 1835); Scholvienia porphyria (Pfeiffer, 1847); Kuschelenia (Bocourtia) purpurata (Reeve, 1849); Kuschelenia (Bocourtia) quechuarum Crawford, 1939; Quechua salteri (Sowerby III, 1890); Kuschelenia (Bocourtia) subfasciata Pfeiffer, 1853; Clathrorthalicus victor (Pfeiffer, 1854). In an addedum a lectotype is being designated for Bulimulus (Drymaeus) interruptus var. pallidus Preston, 1909. An index is included to all taxa mentioned in this paper and the preceding ones in this series (Breure and Ablett 2011, 2012, 2014). PMID:25632243

  8. Marine Mollusca of isotope stages of the last 2 million years in New Zealand. Part 4. Gastropoda (Ptenoglossa, Neogastropoda, Heterobranchia)

    Microsoft Academic Search

    AG Beu

    2011-01-01

    Three new species: Opalia (Pliciscala) flemingi (late Nukumaruan-early Castlecliffian, OIS 71-29?, Wanganui); Kuroshioturris putere (Opoitian-Waipipian, Westland and Hawke's Bay), Antimelatoma waimea (Kapitean-Opoitian, Westland); two new genera: Cryptofusus (Turbinellidae) for New Zealand species formerly referred to Pleia Finlay (Australian); Onoketoma (Conidae, Raphitominae) for 揑nsolentia solitaria King, bathyal Nukumaruan, Palliser Bay. Xymene (sensu stricto; separated again from Axymene, Xymenella and Zeatrophon) is

  9. The population density effects on the reproductive biology of the snail Bradybaena similaris (F閞ussac, 1821) (Mollusca, Gastropoda).

    PubMed

    Oliveira, C S de; Vasconcellos, M C; Pinheiro, J

    2008-05-01

    The influence of population density on some aspects of the reproductive biology of the snail Bradybaena similaris was studied. Molluscs were maintained under 0.2 (isolated), 0.3, 0.6, 1.0, 1.3 and 1.7 snail/m(2) densities. The animals maintained under 0.3 and 0.6 snail/m(2) showed the lowest numbers of eggs laid/snail, being the highest value observed to the 1.7 snail/m(2). The hatching of the snails maintained under 0.3 snail/m(2) density, begun at the 21st day after laying, and the maximum time required to the hatching was 36 days was observed to the eggs came from snails maintained under the densities 0.6, 1.0, 1.3 snail/m(2), respectively. The highest percentage hatchability (55.56%) was observed to isolated snails. The galactogen content in the albumen gland did not seem to accompany the alterations occurred in the reproduction of B. similaris in response to the different population densities. PMID:18660965

  10. Alterations in the mantle epithelium during transition from hatching gland to adhesive organ of Idiosepius pygmaeus (Mollusca, Cephalopoda).

    PubMed

    Cyran, Norbert; Klepal, Waltraud; St鋎ler, Yannick; Sch鰊enberger, J黵g; von Byern, Janek

    2015-02-01

    Epithelial gland systems play an important role in marine molluscs in fabricating lubricants, repellents, fragrances, adhesives or enzymes. In cephalopods the typically single layered epithelium provides a highly dynamic variability and affords a rapid rebuilding of gland cells. While the digestive hatching gland (also named Hoyle organ) is obligatory for most cephalopods, only four genera (Nautilus, Sepia, Euprymna and Idiosepius) produce adhesive secretions by means of glandular cells in an adhesive area on the mantle or tentacles. In Idiosepius this adhesive organ is restricted to the posterior part of the fin region on the dorsal mantle side and well developed in the adult stage. Two gland cell types could be distinguished, which produce different contents of the adhesive. During the embryonic development the same body area is occupied by the temporary hatching gland. The question arises, in which way the hatching gland degrades and is replaced by the adhesive gland. Ultrastructural analyses as well as computer tomography scans were performed to monitor the successive post hatching transformation in the mantle epithelium from hatching gland degradation to the formation of the adhesive organ. According to our investigations the hatching gland cells degrade within about 1 day after hatching by a type of programmed cell death and leave behind a temporary cellular gap in this area. First glandular cells of the adhesive gland arise 7 days after hatching and proceed evenly over the posterior mantle epithelium. In contrast, the accompanying reduction of a part of the dorsal mantle musculature is already established before hatching. The results demonstrate a distinct independence between the two gland systems and illustrate the early development of the adhesive organ as well as the corresponding modifications within the mantle. PMID:25483816

  11. Absence of formation of benzo[a]pyrene/DNA adducts in the cuttlefish (Sepia officinalis, Mollusca: Cephalopoda)

    SciTech Connect

    Lee, P.G.; Lu, L.J.W.; Salazar, J.J.; Holoubek, V. (Univ. of Texas Medical Branch, Galveston, TX (United States))

    1994-01-01

    Benzo[a]pyrene (B[a]P) injected intramuscularly into the base of the arms of cuttlefish was released continuously from the injection site and removed from the organism. Only a portion of the compound accumulated in the body. Twenty-four hr after its injection, 75% of B[a]P applied in olive oil was removed from the cuttlefish, and 1.2% was found in the body outside the head, in site of injection. If the carcinogen was dissolved in dimethylformamide, the removal of B[a]P was slower, so that only 18% of the injected B[a]P was removed from the organism and 0.36% accumulated in the body outside the head 24 hr after injection. The high level of B[a]P in gills and hemolymph 4 hr after injection and the kinetics of the decrease of its concentration with time indicate that these two organs could be involved in the excretion of B[a]P from the body. The B[a]P/DNA adducts characteristic for vertebrates could not be demonstrated in gills, skin, brain, hepatopancreas, and lymphocytes of the cuttlefish 24 hr after injection. The dose of the carcinogene injected into the cuttlefish was 2-4 times higher than the dose resulting in the formation of a high level of B[a]P/DNA adducts in vertebrates. A different metabolism of B[a]P in the tissue of cephalopods, compared to vertebrates, could be less favorable to the process leading to malignant transformation and could explain the absence from the literature of reports of tumors in cephalopods. 15 refs., 1 fig., 2 tabs.

  12. The effect of stocking density on the growth of apple snails native Pomacea bridgesii and exotic Pomacea lineata (Mollusca, Gastropoda).

    PubMed

    Souza J鷑ior, Esmar; De Barros, Jos Carlos N; Paresque, Karla; De Freitas, Rodrigo R

    2013-01-01

    The demand for alternative food sources is currently in evidence in the world and, therefore, the culture of animal species considered not conventional makes this theme relevant and appropriate. In the present study, the species Pomacea lineata and Pomacea bridgesii, each with three stowage densities (0.5 [T1], 1 [T2], and 1.5 [T3] animal/L), were tested. They were analyzed regarding growth rate, weight gain, final biomass, feed conversion and percentage of survival. There was not any statistically significant difference between the different densities for both species. The final average weight in the three waterworks did not differ significantly in P. bridgesii. In P. lineata, T1 (22.3 1.80g) was significantly higher than T2 and T3. On the other hand, the absolute gain of weight in P. lineata and P. bridgesii was significantly higher in T1 (21.9 1.80g and 37.2 6.34g) than in T2 and T3 respectively. In contrast, the gain of biomass of P. lineata and P. bridgesii was significantly higher in T3 (276.3 33.16g and 431.4 37.20g) than in T1 and T2, respectively. Based on the results obtained, all species studied presented potential for aquaculture, mainly P. bridgesii, distinguished for showing a better development even in waterworks with higher densities. PMID:23828367

  13. A cybertaxonomic revision of the micro-landsnail genus Plectostoma Adam (Mollusca, Caenogastropoda, Diplommatinidae), from Peninsular Malaysia, Sumatra and Indochina

    PubMed Central

    Liew, Thor-Seng; Vermeulen, Jaap Jan; Marzuki, Mohammad Effendi bin; Schilthuizen, Menno

    2014-01-01

    Abstract Plectostoma is a micro land snail restricted to limestone outcrops in Southeast Asia. Plectostoma was previously classified as a subgenus of Opisthostoma because of the deviation from regular coiling in many species in both taxa. This paper is the first of a two-part revision of the genus Plectostoma, and includes all non-Borneo species. In the present paper, we examined 214 collection samples of 31 species, and obtained 62 references, 290 pictures, and 155 3D-models of 29 Plectostoma species and 51 COI sequences of 19 species. To work with such a variety of taxonomic data, and then to represent it in an integrated, scaleable and accessible manner, we adopted up-to-date cybertaxonomic tools. All the taxonomic information, such as references, classification, species descriptions, specimen images, genetic data, and distribution data, were tagged and linked with cyber tools and web servers (e.g. Lifedesks, Google Earth, and Barcoding of Life Database). We elevated Plectostoma from subgenus to genus level based on morphological, ecological and genetic evidence. We revised the existing 21 Plectostoma species and described 10 new species, namely, P. dindingensis sp. n., P. mengaburensis sp. n., P. whitteni sp. n., P. kayiani sp. n., P. davisoni sp. n., P. relauensis sp. n., P. kubuensis sp. n., P. tohchinyawi sp. n., P. tenggekensis sp. n., and P. ikanensis sp. n. All the synthesised, semantic-tagged, and linked taxonomic information is made freely and publicly available online. PMID:24715783

  14. On growth and form of irregular coiled-shell of a terrestrial snail: Plectostoma concinnum (Fulton, 1901) (Mollusca: Caenogastropoda: Diplommatinidae)

    PubMed Central

    Kok, Annebelle C.M.; Schilthuizen, Menno; Urdy, Severine

    2014-01-01

    The molluscan shell can be viewed as a petrified representation of the organism抯 ontogeny and thus can be used as a record of changes in form during growth. However, little empirical data is available on the actual growth and form of shells, as these are hard to quantify and examine simultaneously. To address these issues, we studied the growth and form of a land snail that has an irregularly coiled and heavily ornamented shell朠lectostoma concinnum. The growth data were collected in a natural growth experiment and the actual form changes of the aperture during shell ontogeny were quantified. We used an ontogeny axis that allows data of growth and form to be analysed simultaneously. Then, we examined the association between the growth and the form during three different whorl growing phases, namely, the regular coiled spire phase, the transitional constriction phase, and the distortedly-coiled tuba phase. In addition, we also explored the association between growth rate and the switching between whorl growing mode and rib growing mode. As a result, we show how the changes in the aperture ontogeny profiles in terms of aperture shape, size and growth trajectory, and the changes in growth rates, are associated with the different shell forms at different parts of the shell ontogeny. These associations suggest plausible constraints that underlie the three different shell ontogeny phases and the two different growth modes. We found that the mechanism behind the irregularly coiled-shell is the rotational changes of the animal抯 body and mantle edge with respect to the previously secreted shell. Overall, we propose that future study should focus on the role of the mantle and the columellar muscular system in the determination of shell form. PMID:24883245

  15. Extensive population subdivision of the cuttlefish Sepia officinalis (Mollusca: Cephalopoda) around the Iberian Peninsula indicated by microsatellite DNA variation

    Microsoft Academic Search

    M P閞ez-Losada; A Guerra; G R Carvalho; A Sanjuan; P W Shaw

    2002-01-01

    The Atlantic Ocean-Mediterranean Sea junction has been proposed as an important phylogeographical area on the basis of concordance in genetic patterns observed at allozyme, mtDNA and microsatellite DNA markers in several marine species. This study presents microsatellite DNA data for a mobile invertebrate species in this area, the cuttlefish Sepia officinalis, allowing comparison of this relatively new class of DNA

  16. Principal features of the mating system of a large spawning aggregation of the giant Australian cuttlefish Sepia apama (Mollusca: Cephalopoda)

    Microsoft Academic Search

    K. Hall; R. T. Hanlon

    2002-01-01

    Every winter thousands of cuttlefish (Sepia apama Gray) aggregate to spawn along a restricted area of rocky reef in northern Spencer Gulf, South Australia. It is the only known spawning aggregation of cuttlefish in the world and represents an exceptional cuttlefish mating system. Spawning population structure and reproductive behavior were studied quantitatively by underwater visual transects and by focal-animal behavioral

  17. Identification of protein components of egg masses indicates parental investment in immunoprotection of offspring by Biomphalaria glabrata (Gastropoda, Mollusca)

    PubMed Central

    Hathaway, Jennifer J M; Adema, Coen M.; Stout, Barbara A.; Mobarak, Charlotte D; Loker, Eric S

    2009-01-01

    The macromolecules contributed by the freshwater gastropod Biomphalaria glabrata, intermediate host of Schistosoma mansoni, to developing offspring inside egg masses are poorly known. SDS-PAGE fractionated egg mass fluids (EMF) of M line and BB02 B. glabrata were analyzed by MALDI-TOF (MS and tandem MS). A MASCOT database was assembled with EST data from B. glabrata and other molluscs to aid in sequence characterization. Of approximately 20 major EMF polypeptides, 16 were identified as defense-related, including protease inhibitors, a hemocyanin-like factor and tyrosinase (each with possible phenoloxidase activity), extracellular Cu-Zn SOD, two categories of C-type lectins, Gram negative bacteria-binding protein (GNBP), aplysianin/achacin-like protein, as well as versions of lipopolysaccharide binding protein/bacterial permeability increasing proteins (LBP/BPI) that differed from those previously described from hemocytes. Along with two sequences that were encoded by 搖nknown ESTs, EMF also yielded a compound containing a vWF domain that is likely involved in defense and a polypeptide with homology to the Aplysia pheromone temptin. Further study of B. glabrata pheromones is warranted as these could be useful in efforts to control these schistosome-transmitting snails. Several of the EMF polypeptides were contained in the albumen gland, the organ that produces most EMF. Thus parental investment of B. glabrata in immunoprotection of its offspring is indicated to be considerable. PMID:19995576

  18. The Functional and Adaptive Morphology of the Deep-Sea Species of the Arcacea (Mollusca: Bivalvia) from the Atlantic

    Microsoft Academic Search

    G. Oliver; J. A. Allen

    1980-01-01

    Species of two genera, Bathyarca Kobelt (1891) and Bentharca Verrill and Bush (1898), occur beyond the shelf-slope break of the continental margins of the Atlantic. Little is known of these species and descriptions of the morphology of Bathyarca glacialis, B. pectunculoides, B. inaequisculpta, B. corpulenta, Bentharca nodulosa and B. asperula are given. The species of Bathyarca show a progression in

  19. Numerical quantification of Perkinsus marinus in the American oyster Crassostrea virginica (Gmelin, 1791) (Mollusca: Bivalvia) by modern stereology.

    PubMed

    Remacha-Trivi駉, Antonio; Borsay-Horowitz, Doranne; Dungan, Christopher; Gual-Arnau, Ximo; G髆ez-Leon, Javier; Villamil, Luisa; G髆ez-Chiarri, Marta

    2008-02-01

    Species of Perkinsus are responsible for high mortalities of bivalve molluscs world-wide. Techniques to accurately estimate parasites in tissues are required to improve understanding of perkinsosis. This study quantifies the number and tissue distribution of Perkinsus marinus in Crassostrea virginica by modern stereology and immunohistochemistry. Mean total number of trophozoites were (mean +/- SE) 11.80 +/- 3.91 million and 11.55 +/- 3.88 million for the optical disector and optical fractionator methods, respectively. The mean empirical error between both stereological approaches was 3.8 +/- 1.0%. Trophozoites were detected intracellularly in the following tissues: intestine (30.1%), Leydig tissue (21.3%), hemocytes (14.9%), digestive gland (11.4%), gills (6.1%), connective tissues (5.7%), gonads (4.1%), palps (2.2%), muscle (1.9%), mantle connective (0.8%), pericardium (0.7%), mantle epithelium (0.1%), and heart (0.1%). The remaining 0.6% were found extracellularly. Percentages of trophozoite stages were (mean +/- SE): large, log-phase trophonts, i.e., signet rings, 97.0 +/- 1.2%; meronts, 2.0 +/- 0.9%; clusters of small, log-phase trophonts, i.e., merozoites, 1.0 +/- 0.5%. Levels of infection in hemocytes and Leydig tissue were representative of total parasite intensity. These techniques are a powerful tool to follow parasite distribution and invasion, and to further explore mechanisms of Perkinsus spp. pathogenesis in bivalves. PMID:18372631

  20. Numerical Quantification of Perkinsus Marinus in the American Oyster Crassostrea virginicata (Gmelin 1791) (Mollusca: Bivalvia) by Modern Stereology

    EPA Science Inventory

    Species of Perkinsus are responsible for high mortalities of bivalve molluscs world-wide. Techniques to accurately estimate parasites in tissues are required to improve understanding of perkinsosis. This study quantifies the number and tissue distribution of Perkinsus marinus in ...

  1. Life cycle, population dynamics, growth and production of Abra segmentum (Mollusca, Bivalvia) at low salinities in a Mediterranean lagoon

    NASA Astrophysics Data System (ADS)

    Kevrekidis, Theodoros; Kasapis, K.; Kalpia, V.

    2009-12-01

    Aspects of the biology of Abra segmentum were investigated at low salinities in a Mediterranean coastal lagoon (Monolimni Lagoon, Northern Aegean Sea). Monthly samples were collected during the period from February 1998 to January 1999. Recruitment occurred from mid-spring to early autumn (0.3-5.7 psu) and recruits grew during summer and autumn (1.2-5.7 psu), while a major part vanished during next autumn, displaying a maximum life span of about 20 months. A positive correlation was found between the percentage of individuals having a shell length of ?3.5 mm and temperature; age group 0 showed a growth rate of 0.97 mm per month, and the largest individual collected had a 19.76 mm shell length. The population density sharply increased during late spring (0.3-1.2 psu); this increase was followed by a decline during summer and, afterwards, a gradual increase up to late autumn. Secondary production calculated by the size-frequency method gave a mean annual density ( n) of 3,357 individuals m-2, a mean annual biomass ( B) of 21.98 g DW m-2, an annual production ( P) of 73.72 g DW m-2 and a P: B ratio of 3.35. A comparison of the present data with available data of A. segmentum populations from higher salinity habitats revealed that this bivalve in the study area showed a life history pattern similar to that of other populations of the species and a comparatively high growth rate, maximum body size, n, B, P and P: B ratio. Our findings suggest that the studied aspects of A. segmentum biology could not be markedly affected by low salinities.

  2. First record of Cymatium keenae Beu, 1970 (Mollusca: Ranellidae) from Antofagasta Bay, northern Chile, in connection with El Ni駉 events

    NASA Astrophysics Data System (ADS)

    Ashton, Tom; Riascos, Jose M.; Pacheco, Aldo

    2008-03-01

    Cymatium ( Monoplex) keenae Beu, 1970, the neopolitan triton, is a Ranellidae predator distributed in tropical and subtropical waters. In this study we report this species for the first time in Antofagasta Bay, northern Chile. Adult specimens have been found since June 2003 at depths ranging from 5 to 15 m in La Rinconada Marine Reserve (2328'18?S, 7030'46?W) in Antofagasta Bay, near a scallop farming facility. The present findings clearly extend the geographic range of C. keenae, which previously had been reported from La Paz, Gulf of California (Mexico) to Gal醦agos Islands (Ecuador) in the SE Pacific. Previous evidence strongly suggests that the intrusion of this tropical immigrant can be related to warm El Ni駉 episodes. We analyze the key role of the oceanographic characteristics of Antofagasta Bay as potential temporal refuge for this species.

  3. A natural history of the deep-sea aplacophoran Prochaetoderma yongei and its relationship to confamilials (Mollusca, Prochaetodermatidae)

    NASA Astrophysics Data System (ADS)

    Scheltema, Am閘ie H.; Ivanov, Dmitry L.

    2009-09-01

    Previously published studies are woven together into a natural history of a deep-sea aplacophoran mollusc species, Prochaetoderma yongei Scheltema, 1985, and its confamilial species in the Prochaetodermatidae. This amphi-Atlantic species occurs sometimes in great numbers at upper bathyal depths, rivaling polychaetes in numerical dominance. It appears to be an opportunist, with wide geographic and depth distribution, rapid development from lecithotrophic larva to settlement and maturity, and omnivory. A short illustrated morphological description using characters useful for identifying all prochaetodermatid species should prove useful to nontaxonomists whose business is the deep-sea benthic fauna.

  4. Determination of the optimum concentration of eggs and spermatozoa for the production of normal larvae in Pecten maximus (Mollusca, Lamellibranchia)

    Microsoft Academic Search

    Ll. D. Gruffydd; A. R. Beaumont

    1970-01-01

    Kurzfassung Die KammuschelPecten maximus (L.) erzeugt bei 15 C nahezu w鋒rend des ganzen Jahres reife Keimzellen. Der Reifeproze der Geschlechtszellen kann durch Erniedrigung der Temperatur auf 7 bis 8 C arretiert werden. Der Laichvorgang l溥t sich dadurch ausl鰏en, indem Kammmuscheln 2 Stunden lang aus dem Wasser entnommen werden. Danach, innerhalb von 2 bis 4 Stunden nach R點kf黨rung in Meerwasser, werden

  5. Differences in absolute and relative growth between two shell forms of Pinna nobilis (Mollusca: Bivalvia) along the Tunisian coastline

    NASA Astrophysics Data System (ADS)

    Rabaoui, Lotfi; Tlig-Zouari, Sabiha; Katsanevakis, Stelios; Belgacem, Walid; Hassine, Oum Kalthoum Ben

    2011-08-01

    This study investigated the absolute and relative growth patterns of the fan mussel Pinna nobilis along the Tunisian coastline, taking into consideration both the variability among different areas and between the two shell forms "combed" and "straight and wide". Five subpopulations of the species were sampled, one from northern, two from eastern and two from southern Tunisia. Various assumptions on the growth patterns were tested based on an information theory approach and multi-model inference. For absolute growth, the assumption of different growth patterns between the two shell forms of P. nobilis and no difference among subpopulations was the most supported by the data. For the same age, "straight and wide" individuals gained on average greater lengths than the "combed" individuals. The absolute growth of the species was found to be asymptotic and the logistic model was the one most supported by the data. As for the relative growth, apart from the classical allometric model Y = aXb, more complicated models of the form ln Y = f(ln X) that either assumed non-linearities or breakpoints were tested in combination with assumptions for possible differences between the two forms and among subpopulations. Among the eight studied relationships between morphometric characters, the classical allometric model was supported in only two cases, while in all other cases more complicated models were supported. Moreover, the assumption of different growth patterns between the two forms was supported in three cases and the assumption of different growth patterns among subpopulations in four cases. Although precise relationships between the morphometric plasticity of the fan mussel and environmental factors have not been proven in this paper, local small scale constraints might be responsible of the different growth patterns observed in the same locality. A possible co-action of genetic factors should be evaluated in the future.

  6. Desiccation, higher temperatures and upper intertidal limits of three species of sea mussels (Mollusca: Bivalvia) in New Zealand

    Microsoft Academic Search

    V. S. Kennedy

    1976-01-01

    Distribution, abundance, and resistance adaptations to higher temperature and desiccation of three species of intertidal mussels (Mytilus edulis aoteanus, Perna canaliculus and Aulacomya maoriana) were studied in New Zealand. M. edulis aoteanus generally was more abundant upshore, with P. canaliculus dominating downshore. M. edulis aoteanus was more common than P. canaliculus on the outside of mixed-species clumps. Abundance of A.

  7. Reproductive cycle of Tagelus plebeius (Mollusca: Bivalvia) in the estuary of the Cachoeira River, Ilh閡s, Bahia, Brazil.

    PubMed

    Ceuta, L O; Boehs, G

    2012-08-01

    This study characterized the reproductive cycle of the stout razor clam Tagelus plebeius in the estuary of the Cachoeira River, Ilh閡s, Bahia, northeastern Brazil. Samples of 20 animals per collection were taken biweekly from August 2005 to August 2006. The 480 specimens were measured on the antero-posterior axis (length) and then removed from the shell. After macroscopic analysis, the gonads were fixed in Davidson's solution, processed by routine histology and stained by Harris hematoxylin and eosin. The gonads of both males and females appeared milky white, without sexual dimorphism. Microscopic analyses indicated a M: F ratio of 1.06: 1 and continuous reproduction of T. plebeius in the region. The period from August to October showed the most intense spawning. This study provides another example of continuous reproduction of bivalves in tropical waters, and because this species is a heavily exploited fishery resource in the region, it draws attention to the need for a management plan aimed at reducing harvests. PMID:22990828

  8. Reproductive cycle of Anomalocardia brasiliana (Mollusca: Bivalvia: Veneridae) in the estuary of the Cachoeira River, Ilh閡s, Bahia.

    PubMed

    Luz, J R; Boehs, G

    2011-08-01

    The aim of this study was to characterize the reproductive cycle of Anomalocardia brasiliana, typical of the estuarine region of the Cachoeira River, Ilh閡s, Bahia, Brazil. For this purpose, 20 specimens were collected biweekly between August 2005 and August 2006 on an intertidal bank (14 48' 23" S and 39 02' 47" W). The animals were measured on the anteroposterior axis (length), examined macroscopically and removed from the shell and fixed in Davidson's solution. Subsequently, the tissues were impregnated in paraffin, cut into 7 mm sections and stained with Harris hematoxylin and eosin (HE). The slides were examined under a light microscope. The water temperature at the site ranged from 24 to 30.5 篊 (mean: 27.4 篊; SD 1.9), salinity from zero to 23 (mean: 13.7; SD 7.5) and rainfall from 28.3 mm to 248.8 mm monthly (yearly mean: 130 mm). The sample (n = 478) showed a sex ratio (M: F) of 1: 1.2 (p < 0.05) and no cases of hermaphroditism. There was no sexual dimorphism. Males and females showed reproductive synchrony. The reproductive cycle was continuous, with releases of gametes mainly in spring, summer and autumn. These results are similar to those found in other regions, but there was no reproductive rest period as reported for populations in higher latitudes. PMID:21881791

  9. Heavy metals in Patella caerulea (Mollusca, Gastropoda) in polluted and non-polluted areas from the Iskenderun Gulf (Mediterranean Turkey).

    PubMed

    Y鼁erero?lu, T A; G鰇, G; Co?un, H Y; Firat, O; Aslanyavrusu, Sabahattin; Maruldali, Onur; Kargin, F

    2010-08-01

    The concentrations of Cd, Cu, Zn, Fe, Pb, Ni, and Co were measured in gastropod mollusks Patella caerulea in the Mediterranean area. The organisms were collected at two coastal sites in Iskenderun Gulf during winter, spring, summer, and autumn 2008. Samples of the digestive gland, gill, and muscle were analyzed for heavy metals. The aim of study is to determine heavy metal levels in tissues of P. caerulea in different locations. Tissues of P. caerulea from the polluted site showed metal concentrations appreciably higher than unpolluted organisms. The highest metal levels were registered in the digestive gland of P. caerulea. Generally, digestive gland and gills showed higher metal concentrations than muscle. The average concentrations of heavy metals analyzed exhibited the following decreasing order: Fe>Zn>Cu>Ni>Cd>Pb>Co for both stations 1 and 2. Seasonal changes in metal concentrations were observed in the tissues of P. caerulea from a polluted and an unpolluted population. PMID:19543988

  10. Subterranean Biodiversity of Arkansas, Part 2: Status Update of the Foushee Cavesnail, Amnicolacora Hubricht, 1979 (Mollusca: Gastropoda: Hydrobiidae)

    Microsoft Academic Search

    G. O. Graening

    2003-01-01

    cavesnail, Amnicolacora. For the next 25 years, )thing more was known of its status or distribution. To Idressthisand other data deficiencies, a regional inventory subterranean habitats was initiated by a multi-agency msortium (the Ozark Subterranean Biodiversity Project), e results of which are being presented in this manuscript ries. A bioinventoryon 18 August 2002 of FousheeCave r the author, David Kampwerth

  11. New lucinid bivalves from shallow and deeper water of the Indian and West Pacific Oceans (Mollusca, Bivalvia, Lucinidae)

    PubMed Central

    Taylor, John D.; Glover, Emily A.

    2013-01-01

    Abstract Four new species and a new genus of lucinid bivalves are described from shallow and deeper waters in the Indian and West Pacific Oceans. The new genus Scabrilucina (subfamily Lucininae) includes the little-known Scabrilucina victorialis (Melvill, 1899) from the Arabian Sea and Scabrilucina vitrea (Deshayes, 1844) from the Andaman Sea as well as a new species Scabrilucina melvilli from the Torres Strait off northeastern Australia. Ferrocina brunei new species (Lucininae) was recovered from 60 m near oil drilling activities off Borneo; its anatomy confirmed the presence of symbiotic bacteria. Two unusual deeper water species of Leucosphaerinae are described, both species included in on-going molecular analyses; Gonimyrtea ferruginea from 400650 m in the southwest Pacific and Myrtina reflexa from 200825 m off Zanzibar and Madagascar. PMID:24039537

  12. Integrative study of a new cold-seep mussel (Mollusca: Bivalvia) associated with chemosynthetic symbionts in the Marmara Sea

    NASA Astrophysics Data System (ADS)

    Ritt, B閚閐icte; Duperron, S閎astien; Lorion, Julien; Sara Lazar, Cassandre; Sarrazin, Joz閑

    2012-09-01

    Recently, small Idas-like mussels have been discovered living on carbonate crusts associated with cold-seeps in the Marmara Sea. These mussels, here referred to as Idas-like nov. sp., differ morphologically and genetically from another species identified as Idas aff. modiolaeformis, living in the same type of ecosystem in the Nile Deep-Sea Fan (eastern Mediterranean Sea). A phylogenetic analysis confirms the distinction between the two species, which belong to highly divergent lineages. Carbon stable isotope values, as well as the detection of thiotroph-related bacteria in the gill tissue, support the presence of a symbiotic, thiotroph-derived nutrition. In contrast, Idas aff. modiolaeformis displays six different types of symbionts. Finally our size-frequency data suggest that the recruitment is continuous in the examined area. The present study extends the documented distribution of symbiont-bearing mussels to the Marmara Sea, and contributes to the characterisation of biological communities in this recently explored area.

  13. [A metacercarial disease in the dogfish species Umbra limi (Teleostei) and a trematode infestation in a Physa sp. (Mollusca)].

    PubMed

    Foersch, W; Reichenbach-Klinke, H H; Schaller, D; Schmidt, K

    1984-01-01

    A metacercarial infestation is reported in Canadian Umbra limi and a mass infestation by trematodes in Physa sp. from the same locality. Trials made by using parasitised snails showed that both parasites are not of the same species. PMID:6495318

  14. Review of Baeolidia, the largest genus of Aeolidiidae (Mollusca: Nudibranchia), with the description of five new species.

    PubMed

    Carmona, Leila; Pola, Marta; Gosliner, Terrence M; Cervera, Juan Lucas

    2014-01-01

    This paper discusses the systematics of the aeolid genus Baeolidia Bergh, 1888. To date, this monophyletic genus is the most diverse within Aeolidiidae with sixteen valid species. Excluding Baeolidia cryoporos Bouchet, 1977, the genus is restricted to the Indo-Pacific and Eastern Pacific. Species of Baeolidia show a huge intrageneric variability in several morphological characters. Only oral glands, if present, may distinguish Baeolidia from other aeolidiids genera. Aeolidiella occidentalis Bergh, 1875, Aeolidiella faustina Bergh, 1900 and Spurilla orientalis Bergh, 1905 are transferred to Baeolidia but they are considered nomina dubia. Five new species, Baeolidia rieae sp. nov., Baeolidia variabilis sp. nov., Baeolidia lunaris sp. nov., Baeolidia gracilis sp. nov. and Baeolidia scottjohnsoni sp. nov. are described. PMID:24871026

  15. Development and validation of an OECD reproductive toxicity test guideline with the pond snail Lymnaea stagnalis (Mollusca, Gastropoda).

    PubMed

    Ducrot, Virginie; Askem, Clare; Azam, Didier; Brettschneider, Denise; Brown, Rebecca; Charles, Sandrine; Coke, Ma飏a; Collinet, Marc; Delignette-Muller, Marie-Laure; Forfait-Dubuc, Carole; Holbech, Henrik; Hutchinson, Thomas; Jach, Arne; Kinnberg, Karin L; Lacoste, C閐ric; Le Page, Gareth; Matthiessen, Peter; Oehlmann, J鰎g; Rice, Lynsey; Roberts, Edward; Ruppert, Katharina; Davis, Jessica Elphinstone; Veauvy, Clemence; Weltje, Lennart; Wortham, Ruth; Lagadic, Laurent

    2014-12-01

    The OECD test guideline development program has been extended in 2011 to establish a partial life-cycle protocol for assessing the reproductive toxicity of chemicals to several mollusk species, including the great pond snail Lymnaea stagnalis. In this paper, we summarize the standard draft protocol for a reproduction test with this species, and present inter-comparison results obtained in a 56-day prevalidation ring-test using this protocol. Seven European laboratories performed semi-static tests with cultured snails of the strain Renilys exposed to nominal concentrations of cadmium chloride (from 53 to 608?gCdL(-1)). Cd concentrations in test solutions were analytically determined to confirm accuracy in the metal exposure concentrations in all laboratories. Physico-chemical and biological validity criteria (namely dissolved oxygen content >60% ASV, water temperature 201癈, control snail survival >80% and control snail fecundity >8 egg-masses per snail over the test period) were met in all laboratories which consistently demonstrated the reproductive toxicity of Cd in snails using the proposed draft protocol. Effect concentrations for fecundity after 56days were reproducible between laboratories (68

  16. Do the changes in temperature and light affect the functional response of the benthic mud snail Heleobia australis (Mollusca: Gastropoda)?

    PubMed

    Magalh鉫s, Thaisa R F; Neves, Raquel A F; Valentin, Jean L; Figueiredo, Gisela M

    2014-09-01

    The aim of this study was to determine the influence of temperature increase combined to conditions of light incidence on functional response of Heleobia australis. Experiments were conducted using nine to ten food concentrations for each treatment: 20癈 without light; 30癈 without light and, 30癈 under low light intensity. For each experiment, the functional response type III (sigmoidal) was fitted and equation parameters were determined. Results suggest that, if the sediment temperature increases, H. australis will not have its ingestion rates affected negatively, whilst its feeding behavior seems to be negatively affected by light. Ingestion rates estimated for organic content in the Guanabara Bay were: 0.34 礸C ind-1h-1 at 20癈 without light, 1.44 礸C ind-1h-1 at 30癈 without light and 0.64 礸C ind-1h-1 at 30癈 under light incidence. Higher ingestion rates were estimated at the high temperature, even under light incidence, and temperature seems to have outweighed the light effect. In contrast, if higher carbon content is considered, despite high temperature, the experiment conducted with light incidence showed lower ingestion rates than those from the experiment at 20癈 without light. This study provides the first quantification of H. australis ingestion rates and the effects that changes in temperature and light have on its feeding behavior. PMID:25014915

  17. A new species of Pulvinites (Mollusca: Bivalvia) from the upper Paleocene Paspotansa Member of the Aquia Formation in Virginia ( USA).

    USGS Publications Warehouse

    Ward, L.W.; Waller, T.R.

    1988-01-01

    Pulvinites lawrencei n.sp. is described from the upper Paleocene (Landenian Stage) Paspotansa Member of the Aquia Formation in Stafford County, Virginia. This is the first report of a member of the pteriacean family Pulvinitidae in the Tertiary on either side of the Atlantic, the only other post-Mesozoic records of Pulvinites being in the Paleocene of California and the present-day Pacific off southeast Australia. The stratigraphic setting and co-occurring molluscan assemblage of the new species indicate shallow-shelf, open-marine conditions with near normal salinities. -Authors

  18. THE BEHAVIOR OF LOLIGO OPALESCENS (MOLLUSCA: CEPHALOPODA) AS OBSERVED BY A REMOTELY OPERATED VEHICLE (ROV). (R825381)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  19. "First" abyssal record of Stenosemus exaratus (G.O.燬ars, 1878) (Mollusca, Polyplacophora) in爐he燦orth-Atlantic Ocean.

    PubMed

    Allcock, Louise; Schwabe, Enrico

    2013-01-01

    The first proven abyssal record of Stenosemus exaratus (G.O. Sars, 1878) is presented on the basis of an ROV study in the Irish Sea. For the first time in situ images of the species and data on the environmental parameters are provided. PMID:23794838

  20. Evidence for accumulation of Synechococcus elongatus (Cyanobacteria: Cyanophyceae) in the tissues of the oyster Crassostrea gigas (Mollusca: Bivalvia).

    PubMed

    Avila-Poveda, Omar Hernando; Torres-Ari駉, Alejandra; Gir髇-Cruz, Diego Ademir; Cuevas-Aguirre, Angel

    2014-10-01

    Cyanobacteria appear to have direct relations with mollusks in several aspects. This is the first time, distinguishing Gram-negative cyanoprokaryotic Synechococcus elongatus as bright yellow-gold autofluorescence by Lillie's and Hiss' staining methods on paraffin-embedded tissues of Crassostrea gigas. Three diets: cyanoprokaryotes, cyanoprokaryotes with microalgae, and only microalgae were evaluated. Cyanoprokaryotes were intact, densely bundled, and immersed in the cytosol of the digestive gland, connective tissue, mantle, and gonad of C. gigas, revealing an accumulation systemic without tissue damage observed by histology. Unexpectedly, cyanoprokaryotes were slightly most accumulated with microalgae diet by each of the tissues of the C. gigas than with any other diets. Cyanoprokaryotes tend to be in mean slightly higher in the digestive gland than in any other tissues respectively for each diet, although these values are closely similar to connective tissue. A possible order of exposure of the oyster tissues to accumulation of cyanoprokaryotes was digestive gland, connective tissue, mantle, and gonad. Thereby, the digestive gland could be the major target tissue for the accumulation. Our observations provide a valuable insight regarding the ability of cyanoprokaryotes to penetrate, spread, and remain inside the oyster tissues, suggesting for S. elongatus: (1) a pre-accumulation in oyster tissues from the natural environment, (2) a phagocytosis and/or endocytosis process rather than ingestion and extracellular digestion, (3) an apparent cellular division in the cytosol of oyster tissues, (4) an apparent inter-tissue movement, and (5) a possible endosymbiosis between C. gigas and S. elongatus. Hereby, it is possible that S. elongatus have a well-developed host-endobiont relationship with oysters, and thereby support future work toward a description of the escape and spreading mechanisms of S. elongatus inside the tissues of mollusks, and put forward questions as why it is there? and are the cells active or inactive? PMID:25109761

  1. [Evolutionary history of Metazoa, ancestral status of the bilateria clonal reproduction, and semicolonial origin of the mollusca].

    PubMed

    Martynov, A V

    2013-01-01

    Evolutionary history of any metazoan group is a history of the entire ontogenetic cycles instead of separate stages and genes only. Ontogeny in the most objective way links two key components of the biological systematics: historically-independent characters attribution and phylogeny itself. A general theory encompassing "static" traditional taxonomy and dynamic evolutionary process, based on the ontogenetic transformation of the organisms' shape is suggested here to term as ontogenetic systematics. As an important practical implication of the ontogenetic systematics, a new model of the bilaterian metazoans evolution is suggested. The new model considers asexual clonal reproduction as a central feature of the ancestral ontogenetic cycles of basal Bilateria. The new scenario resolves several notable contradictions, e.g. morphological, ontogenetic and molecular similarities of Pogonophora, Vestimentifera, Phoronida simultaneously to protostomian Spiralia (Lophotrochozoa) and Deuterostomia. The suggested model implies individuation (possibly multiple) of ancestral semicolonial sedentary group as a major factor of the basal Bilateria diversification. In the late Ediacaran and early Cambrian thus existed ancestral bilaterian group that shared characters of both Spiralia and Deuterostomia and possessed polyp-shape body and cephalic secretory shield (like in modern Pterobranchia and Vestimentifera), that later on reduced in various lines. This ancestral taxon in rank of supraphylum is suggested to term as Carmaphora (shield-bearers). Presence of the enigmatic sedentary fossil of the genus Cloudina with vestimentiferan-like tubes and evident clonal reproduction already in the late Ediacaran, and most recent found of an unquestionable pterobranch already in the early Cambrian support the new model of Bilateria evolution. PMID:24163984

  2. A new genus and species of Thyasiridae (Mollusca, Bivalvia) from deep-water, Beaufort Sea, northern Alaska.

    PubMed

    Valentich-Scott, Paul; Powell, Charles L; Ii; Lorenson, Thomas D; Edwards, Brian E

    2014-01-01

    Bivalve mollusk shells were collected in 2350 m depth in the Beaufort Sea, Arctic Ocean off northern Alaska. Initial identification suggested the specimens were a member of the bivalve family Thyasiridae, but no known eastern Pacific or Arctic living or fossil thyasirid resembled these deep-water specimens. Comparisons were made with the type of the genera Maorithyas Fleming, 1950, Spinaxinus Oliver & Holmes, 2006, Axinus Sowerby, 1821, and Parathyasira Iredale, 1930. We determined the Beaufort Sea species represents a new genus, herein described as Wallerconcha. These specimens also represent a new species, herein named Wallerconchasarae. These new taxa are compared with known modern and fossil genera and species of thyasirds. PMID:25589851

  3. [Genetic and morphological variability of the gastropod mollusk Nucella heyseana (Mollusca, Gastropoda) in the environmental optimum and pessimum].

    PubMed

    Kartavtsev, Iu F; Rybnikova, I G; Sitnikov, A V; Amachaeva, E Iu; Svin'ina, O V

    2000-10-01

    Genotypic variability at six allozyme loci and six morphological shell characters was examined in 450 individuals (four samples) of mollusk Nucella heysana from the Vrangel' Bight (Nakhodka Bay) and the Vostok Bay (Peter the Great Gulf, Sea of Japan). An analysis of variation in allele frequencies showed that each of the two localities (Vostok and Nakhodka bays) in the analyzed region is inhabited by a single, albeit genetically heterogeneous, population. A canonical analysis and an analysis of variance of individual heterozygosity (Ho) and morphological variation indicate an association between Ho and morphological variation depending on habitat (interaction) in settlements in the Vrangel' Bight and, to a lesser extent, in the Vostok Bay. These results indicate that, in extreme environmental conditions, allozyme phenotypes may be selected either themselves or as markers of genes linked with them. PMID:11094745

  4. Mulinia lateralis (Mollusca: Bivalvia) die-off in South Carolina: discovery of a vector for two elasmobranch cestode species.

    PubMed

    de Buron, Isaure; Roth, Patricia B; Bergquist, Derk C; Knott, David M

    2013-02-01

    Unexplained and episodic die-offs of the dwarf surf clam, Mulinia lateralis , have been reported on the West Atlantic coast, with such an occurrence in South Carolina in June 2010. A sample of live clams from the 2010 South Carolina event was collected, and 200 clams were measured and necropsied. Two species of tapeworm larvae were observed. Plerocercoids (Duplicibothrium sp.) occupied the digestive gland ducts, and merocercoids (Rhodobothrium sp.) were found beneath the mantle. Specimens of both species were sequenced to obtain partial 28S rRNA gene sequences, and they were identified as the tetraphyllidean D. minutum and the rhinebothriidean R. paucitesticulare, based on an NCBI Standard Nucleotide BLAST search. Of the 200 clams, 2.1% were infected with merocercoids (mean intensity 1.3 0.2) and 75% with plerocercoids (mean intensity 4.3 3.7). Intensity of infection by plerocercoids increased significantly with individual shell length. The presence of plerocercoids was associated with enlargement of the digestive gland ducts, but no other pathology was observed. Because uninfected clams were abundant among the stranded molluscs, these parasites are not considered to be the causative agent of the die-off. This is a new host record for both elasmobranch tapeworms. PMID:22924916

  5. Is there a geographical pattern in the breeding system of a complex of hermaphroditic slugs (Mollusca: Gastropoda: Carinarion)?

    PubMed

    Jordaens, K; Geenen, S; Reise, H; Van Riel, P; Verhagen, R; Backeljau, T

    2000-12-01

    Allozyme analyses of the hermaphroditic slugs Arion (Carinarion) fasciatus, A. (C.) circumscriptus and A. (C.) silvaticus have suggested that the three species in North America and north-west Europe predominantly reproduce uniparentally, most probably by selfing. We used allozyme electrophoresis to investigate the population genetic structure of these species throughout a larger part of their native European distribution. Our results show that the previously reported "species" specific allozyme markers are no longer valid if populations from central Europe are investigated, and A. fasciatus and A. silvaticus appear to be "paraphyletic" taxa. In contrast to the general belief that selfing organisms show low gene diversities, the high selfing rates in N-NE European Carinarion do not necessarily result in low gene diversities. Moreover, our data suggest a geographical pattern in the prevalence of outcrossing, at least in A. fasciatus, with selfing in N-NE Europe and a mixed breeding system (i.e. selfing and outcrossing) in central Europe. Possible scenarios for the disjunct distribution of breeding systems in Carinarion are discussed. PMID:11240623

  6. Is there a geographical pattern in the breeding system of a complex of hermaphroditic slugs (Mollusca: Gastropoda: Carinarion)?

    Microsoft Academic Search

    Kurt Jordaens; Sofie Geenen; Heike Reise; Patrick van Riel; Ron Verhagen; Thierry Backeljau

    2000-01-01

    Allozyme analyses of the hermaphroditic slugs Arion (Carinarion) fasciatus, A. (C.) circumscriptus and A. (C.) silvaticus have suggested that the three species in North America and north-west Europe predominantly reproduce uniparentally, most probably by selfing. We used allozyme electrophoresis to investigate the population genetic structure of these species throughout a larger part of their native European distribution. Our results show

  7. On some Vetigastropoda (Mollusca, Gastropoda) from the Plio-Pleistocene of the Philippines with descriptions of three new species.

    PubMed

    Helwerda, Renate Ariane; Wesselingh, Frank Pieter; Williams, Suzanne T

    2014-01-01

    We studied representatives of seven vetigastropod families in an extremely well-preserved Plio-Pleistocene mollusc fauna found in relatively deep water sediments (c. 200-300 m paleodepth) from the north-western Philippines. The fauna is systematically described and its paleoenvironmental and paleobiogeographical character is explored. Twenty-six species of gastropods were studied, three of which are described as new: Halystina conoidea n. sp., Calliotropis arenosa n. sp. and Ethminolia wareni n. sp. Four new combinations are proposed: Pseudotalopia taiwanensis (Chen, 2006), Solariella segersi (Poppe, Tagaro & Dekker, 2006), Zetela tabakotanii (Poppe, Tagaro & Dekker, 2006) and Ilanga konos (Vilvens, 2009). Fourteen species are known living. Most extant species nowadays occur around the Philippines. Two of the species also occur in Neogene deposits from western Pacific islands. The new fauna offers insights into the character of relatively deep water Indo-West Pacific mollusc faunas prior to the onset of the late Quaternary ice ages. PMID:24869812

  8. Genetic structure of Onchidium "struma" (Mollusca: Gastropoda: Eupulmonata) from the coastal area of China based on mtCO I.

    PubMed

    Zhou, Na; Shen, Heding; Chen, Cheng; Sun, Bianna; Zheng, Pei; Wang, Chengnuan

    2014-08-01

    Abstract The genetic diversity and population genetic structure of Onchidium "struma" were investigated using mitochondrial cytochrome c oxidase subunit I (CO I) gene sequences. A total of 240 individuals representing 10 collection sites from across a large portion of its known range were included in the analysis. Overall, 42 haplotypes were defined and 97 polymorphic sites were observed. The O. "struma" populations had high haplotype diversity (0.9280) and nucleotide diversity (0.0404). We inferred that the early maturity and extensive survival habitat led to high genetic diversity of O. "struma" populations in China. Bayesian analysis and SAMOVA analysis showed significant genetic differentiation among populations and all populations were divided into two groups, (HK and HN) versus (GY, DF, CX, CN, ND and XM). The Mantel test revealed no significant correlation between geographic distance and genetic distance (r?=?0.251; p?=?0.058). Restricted gene flow caused by a shorter term pelagic veliger stage and limited dispersal potential were inferred to result in genetic differentiation among populations based on nested analysis. HK population might be an invasive species by artificial transplantation. PMID:25103423

  9. The genetic dynamics of the rapid and recent colonization of Denmark by Arion lusitanicus (Mollusca, Pulmonata, Arionidae)

    Microsoft Academic Search

    S. Engelke; J. K鰉pf; K. Jordaens; J. Tomiuk; E. D. Parker

    2011-01-01

    We describe the genetic dynamics of the recent establishment of the 慖berian slug, Arion lusitanicus J. Mabille 1868, in Denmark and compare its population structure to two other members of the 憀arge Arion complex, Arion ater ater, native to Denmark, and Arion ater rufus, introduced into Denmark in the early 1900s. Assaying allozyme polymorphism at seven enzyme loci, we found

  10. Opisthobranchs from the western Indian Ocean, with descriptions of two new species and ten new records (Mollusca, Gastropoda)

    PubMed Central

    Yonow, Nathalie

    2012-01-01

    Abstract Seventy species of opisthobranchs are described in this work based on collections from the Persian Gulf, Socotra, Kenya, Zanzibar, Madagascar, La R閡nion, Mauritius, the Seychelles, the Maldives, and Sri Lanka. Ten species are newly recorded from the western Indian Ocean and four species are recorded in the scientific literature for the first time since their original descriptions. Two species are described as new: Cyerce bourbonica sp. n. from La R閡nion and Doriopsilla nigrocerasp. n. from the Persian Gulf coast of Saudi Arabia. Chromodoris cavae is removed from its synonymy with Chromodoris tennentana and redescribed from specimens from La R閡nion, while several new synonyms are proposed for some commonly occurring species. Risbecia bullockii is recorded for the second time from the Indian Ocean and assigned to its correct genus. PMID:22711992

  11. SPATIAL DISTRIBUTION OF LYMNAEIDAE (MOLLUSCA, BASOMMATOPHORA), INTERMEDIATE HOST OF Fasciola hepatica LINNAEUS, 1758 (TREMATODA, DIGENEA) IN BRAZIL

    PubMed Central

    Medeiros, Camilla; Scholte, Ronaldo Guilherme Carvalho; D'醰ila, Sthefane; Caldeira, Roberta Lima; Carvalho, Omar dos Santos

    2014-01-01

    Snails of the family Lymnaeidae act as intermediate hosts in the biological cycle of Fasciola hepatica, which is a biological agent of fasciolosis, a parasitic disease of medical importance for humans and animals. The present work aimed to update and map the spatial distribution of the intermediate host snails of F. hepatica in Brazil. Data on the distribution of lymnaeids species were compiled from the Collection of Medical Malacology (Fiocruz-CMM, CPqRR), Collection of Malacology (MZUSP), 揝peciesLink (CRIA) network and through systematic surveys in the literature. Our maps of the distribution of lymnaeids show that Pseudosuccinea columella is the most common species and it is widespread in the South and Southeast with few records in the Midwest, North and Northeast regions. The distribution of the Galba viatrix, G. cubensis and G. truncatula showed a few records in the South and Southeast regions, they were not reported for the Midwest, North and Northeast. In addition, in the South region there are a few records for G. viatrix and one occurrence of Lymnaea rupestris. Our findings resulted in the first map of the spatial distribution of Lymnaeidae species in Brazil which might be useful to better understand the fasciolosis distribution and delineate priority areas for control interventions. PMID:24879003

  12. Antimicrobial activities of the tissue extracts of Babylonia spirata Linnaeus, 1758 (Mollusca: Gastropoda) from Thazhanguda, southeast coast of India

    PubMed Central

    Periyasamy, N; Srinivasan, M; Balakrishnan, S

    2012-01-01

    Objective To investigate the antimicrobial activity of the tissue extracts of Babylonia spirata (B. spirata) against nine bacterial and three fungal pathogens. Methods Crude extract of gastropod was tested for inhibition of bacterial and fungal growth. Antibacterial assay was carried out by disc diffusion method and in vitro antifungal activity was determined against Czapex Dox agar. The antimicrobial activity was measured accordingly based on the inhibition zone around the disc impregnated with gastropod extract. Molecular size of muscle protein was determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). And fourier transform infrared spectroscopy (FTIR) spectro photometry analysis was also studied. Results The maximum inhibition zone (12 mm) was observed against Pseudomonas aeruginosa in the crude ethanol extract of B. spirata and the minimum inhibition zone (2 mm) was noticed against Staphylococcus aureus in the crude methanol extract of B. spirata. Water extract of B. spirata showed the highest activity against Vibrio parahaemolyticus, Staphylococcus aureus and Candida albicans. Ethanol, acetone, methanol, chloroform and water extracts showed antimicrobial activity against almost all the bacteria and fungus. Compared with water extracts, ethanol and methanol extracts showed higher activity against all pathogens. The molecular weight of protein of the gastropod sample ranged from 2-110 kDa on SDS-PAGE. FTIR analysis revealed the presence of bioactive compounds signals at different ranges. Conclusions The research shows that the great medicinal value of the gastropod muscle of B. spirata may be due to high quality of antimicrobial compounds. PMID:23569831

  13. Some effects of heavy metals and polychlorinated biphenyls on the estuarine organisms Brachidontes recurvus (Mollusca) and Penaeus setiferus (Crustacea

    E-print Network

    Green, Felton Allen

    1975-01-01

    thus consisted of the sing1e valve with the intact mantle and dimibranch. 21 All shells, animals, and mantle-shell prepar ations were then placed in 5 liters of seawater held at 25 C by a constant tem- 0 perature water bath. The water was dosed... immediately after exposure. Calcium deposition was measured for B. recurvus and revealed that no significant shell growth occurred while these animals are being held in the laboratory under the conditions studied. The effect of mercury on the growth...

  14. Differential transcriptomic responses of Biomphalaria glabrata (Gastropoda, Mollusca) to bacteria and metazoan parasites, Schistosoma mansoni and Echinostoma paraensei (Digenea, Platyhelminthes)

    PubMed Central

    Adema, Coen M; Hanington, Patrick C.; Lun, Cheng-Man; Rosenberg, George H.; Aragon, Anthony D; Stout, Barbara A; Richard, Mara L. Lennard; Gross, Paul S.; Loker, Eric S

    2009-01-01

    A 70-mer oligonucleotide-based microarray (1152 features) that emphasizes stress and immune responses factors was constructed to study transcriptomic responses of the snail Biomphalaria glabrata to different immune challenges. In addition to sequences with relevant putative ID and Gene Ontology (GO) annotation, the array features non-immune factors and unknown B. glabrata ESTs for functional gene discovery. The transcription profiles of B. glabrata (3 biological replicates, each a pool of 5 snails) were recorded at 12 hours post wounding, exposure to Gram negative or Gram positive bacteria (Escherichia coli and Micrococcus luteus, respectively), or infection with compatible trematode parasites (S. mansoni or E. paraensei, 20 miracidia/snail), relative to controls, using universal reference RNA. The data were subjected to Significance Analysis for Microarrays (SAM), with a false positive rate (FPR) ?10%. Wounding yielded a modest differential expression profile (27 up/21 down) with affected features mostly dissimilar from other treatments. Partially overlapping, yet distinct expression profiles were recorded from snails challenged with E. coli (83 up/20 down) or M. luteus (120 up/42 down), mostly showing up-regulation of defense and stress-related features. Significantly altered expression of selected immune features indicates that B. glabrata detects and responds differently to compatible trematodes. Echinostoma paraensei infection was associated mostly with down regulation of many (immune-) transcripts (42 up/68 down), whereas S. mansoni exposure yielded a preponderance of up-regulated features (140 up/23 down), with only few known immune genes affected. These observations may reflect the divergent strategies developed by trematodes during their evolution as specialized pathogens of snails to negate host defense responses. Clearly, the immune defenses of B. glabrata distinguish and respond differently to various immune challenges. PMID:19962194

  15. New lucinid bivalves from shallow and deeper water of the Indian and West Pacific Oceans (Mollusca, Bivalvia, Lucinidae).

    PubMed

    Taylor, John D; Glover, Emily A

    2013-01-01

    Four new species and a new genus of lucinid bivalves are described from shallow and deeper waters in the Indian and West Pacific Oceans. The new genus Scabrilucina (subfamily Lucininae) includes the little-known Scabrilucina victorialis (Melvill, 1899) from the Arabian Sea and Scabrilucina vitrea (Deshayes, 1844) from the Andaman Sea as well as a new species Scabrilucina melvilli from the Torres Strait off northeastern Australia. Ferrocina brunei new species (Lucininae) was recovered from 60 m near oil drilling activities off Borneo; its anatomy confirmed the presence of symbiotic bacteria. Two unusual deeper water species of Leucosphaerinae are described, both species included in on-going molecular analyses; Gonimyrtea ferruginea from 400-650 m in the southwest Pacific and Myrtina reflexa from 200-825 m off Zanzibar and Madagascar. PMID:24039537

  16. Freshwater snails (Mollusca: Gastropoda) from the Commonwealth of Dominica with a discussion of their roles in the transmission of parasites

    E-print Network

    Dillon, Robert T.

    and H. trivolvis are established on Dominica, West Indies. We tested a limited number of M. tuberculata Indies The Commonwealth of Dominica is a small (790 km2 ) mountainous island nation in the West Indies and veterinary health significance of these snails. Key words: Biomphalaria, Gundlachia, Helisoma, Physa, West

  17. Microsatellite loci for dreissenid mussels (Mollusca: Bivalvia: Dreissenidae) and relatives: markers for assessing exotic and native populations.

    PubMed

    Feldheim, Kevin A; Brown, Joshua E; Murphy, Douglas J; Stepien, Carol A

    2011-07-01

    We developed and tested 14 new polymorphic microsatellite loci for dreissenid mussels, including the two species that have invaded many freshwater habitats in Eurasia and North America, where they cause serious industrial fouling damage and ecological alterations. These new loci will aid our understanding of their genetic patterns in invasive populations as well as throughout their native Ponto-Caspian distributions. Eight new loci for the zebra mussel Dreissena polymorpha polymorpha and six for the quagga mussel D. rostriformis bugensis were compared with new results from six previously published loci to generate a robust molecular toolkit for dreissenid mussels and their relatives. Taxa tested include D. p. polymorpha, D. r. bugensis, D. r. grimmi, D. presbensis, the 'living fossil'Congeria kusceri, and the dark false mussel Mytilopsis leucophaeata (the latter also is invasive). Overall, most of the 24 zebra mussel (N = 583) and 13 quagga mussel (N = 269) population samples conformed to Hardy-Weinberg equilibrium expectations for the new loci following sequential Bonferroni correction. The 11 loci (eight new, three previously published) evaluated for D. p. polymorpha averaged 35.1 alleles and 0.72 mean observed heterozygosity per locus, and 25.3 and 0.75 for the nine loci (six new, three previously published) developed for D. r. bugensis. All but three of these loci successfully amplified the other species of Dreissena, and all but one also amplified Congeria and Mytilopsis. All species and populations tested were significantly divergent using the microsatellite data, with neighbour-joining trees reflecting their evolutionary relationships; our results reveal broad utility for resolving their biogeographic, evolutionary, population and ecological patterns. PMID:21457480

  18. Freshwater snails (Mollusca: Gastropoda) from the Commonwealth of Dominica with a discussion of their roles in the transmission of parasites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We collected six species of freshwater snails from Dominica, including Biomphalaria kuhniana, Gundlachia radiata Helisoma (= Planorbella) trivolvis, Melanoides tuberculata, Neritina punctulata, and Physa marmorata. Our collections indicate that un-reported species such as Gundlachia radiata and Hel...

  19. Evolutionary Dynamics of rDNA Clusters in Chromosomes of Five Clam Species Belonging to the Family Veneridae (Mollusca, Bivalvia)

    PubMed Central

    P閞ez-Garc韆, Concepci髇; Hurtado, Ninoska S.; Mor醤, Paloma; Pasantes, Juan J.

    2014-01-01

    The chromosomal changes accompanying bivalve evolution are an area about which few reports have been published. To improve our understanding on chromosome evolution in Veneridae, ribosomal RNA gene clusters were mapped by fluorescent in situ hybridization (FISH) to chromosomes of five species of venerid clams (Venerupis corrugata, Ruditapes philippinarum, Ruditapes decussatus, Dosinia exoleta, and Venus verrucosa). The results were anchored to the most comprehensive molecular phylogenetic tree currently available for Veneridae. While a single major rDNA cluster was found in each of the five species, the number of 5S rDNA clusters showed high interspecies variation. Major rDNA was either subterminal to the short arms or intercalary to the long arms of metacentric or submetacentric chromosomes, whereas minor rDNA signals showed higher variability. Major and minor rDNAs map to different chromosome pairs in all species, but in R. decussatus one of the minor rDNA gene clusters and the major rDNA cluster were located in the same position on a single chromosome pair. This interspersion of both sequences was confirmed by fiber FISH. Telomeric signals appeared at both ends of every chromosome in all species. FISH mapping data are discussed in relation to the molecular phylogenetic trees currently available for Veneridae. PMID:24967400

  20. A new species of Dicyemennea Whitman, 1883 (Phylum Dicyemida) from Sepia latimanus (Mollusca: Cephalopoda: Decapodidae) off Okinawa, Japan.

    PubMed

    Furuya, Hidetaka

    2006-11-01

    A new species of dicyemid mesozoan is described from a cuttlefish Sepia latimanus Quoy and Gaimard collected off Nago, Naha and Onnason, Okinawa Islands, Ryukyu Islands, Japan. Dicyemennea ryukyuense n. sp. is a large species that reaches about 5 mm in length. The vermiform stage is characterised by 23 peripheral cells, a conical calotte and an axial cell that extends to the base of the propolar cells. The infusoriform embryo consists of 37 cells; two nuclei are present in each urn cell and the refringent bodies are solid. In the type of reproductive strategy, rhombogens of D. ryukyuense form a small number of infusorigens and produce a relatively large number of gametes per infusorigen. In the family Dicyemidae, Dicyemennea Whitman, 1883 is the largest group after Dicyema von K鰈liker, 1849. Other dicyemid species, including those belonging to Dicyema, were not detected. Dicyemids have never previously been detected in cephalopods living on corals and rocks off the Ryukyu Islands, even though they are benthonic in habitat. This is the first report of a dicyemid mesozoan from S. latimanus and also from off the Ryukyu Islands. S. latimanus inhabits coral reefs, often swimming over the coral but usually lying on the sandy bottom. Dicyemids cannot possibly infect cephalopods which live exclusively over coral and rock. PMID:16955340

  1. Large scale population structure and gene flow in the planktonic developing periwinkle, Littorina striata, in Macaronesia (Mollusca: Gastropoda)

    Microsoft Academic Search

    Hans De Wolf; Ron Verhagen; Thierry Backeljau

    2000-01-01

    Allozymes were used to investigate the genetic structure of 42 populations of the planktonic developing, Macaronesian periwinkle Littorina striata, throughout its entire geographic range (Azores, Madeira, Canary Islands and Cape Verde Islands). This periwinkle is presumed to have a high dispersal and gene flow potential, because it has a planktonic development. It is therefore expected to show little population genetic

  2. Large-scale patterns of shell variation in Littorina striata , a planktonic developing periwinkle from Macaronesia (Mollusca: Prosobranchia)

    Microsoft Academic Search

    H. De Wolf; T. Backeljau; S. Van Dongen; R. Verhagen

    1998-01-01

    Littorina striata King and Broderip, 1832 is a strictly Macaronesian, intertidal periwinkle with planktonic development. The species displays\\u000a a high degree of shell variation involving size and sculpture (nodulose vs smooth shells). The present work provides a preliminary\\u000a account of some aspects of this shell variation on wave-exposed shores over the entire geographical range of the species.\\u000a Based on morphological

  3. Annotated type catalogue of Bothriembryon (Mollusca, Gastropoda, Orthalicoidea) in Australian museums, with a compilation of types in other museums

    PubMed Central

    Breure, Abraham S.H.; Whisson, Corey S.

    2012-01-01

    Abstract Type material of 41 Australian Bothriembryon taxa present in Australian museums is critically listed, indicating systematic issues that need to be resolved in further studies. Information on additional type material of 22 taxa in non-Australian museums is compiled. The seven fossil taxa known so far are included in this catalogue. Based on the current systematic position, 38 species are treated in this paper. Bothriembryon jacksoni Iredale, 1939, Bothriembryon notatus Iredale, 1939, Bothriembryon praecelsus Iredale, 1939 and Bothriembryon serpentinus Iredale, 1939 are elevated to species level. Bothriembryon gratwicki (Cox, 1899) is listed as status to be determined. PMID:22679384

  4. Description of a new species of Thais (Mollusca: Neogastropoda: Muricidae) from Taiwan, based on morphological and allozyme analyses.

    PubMed

    Tan, K S; Liu, L L

    2001-12-01

    Thais keluo sp. nov. is described from intertidal shores of southwest Taiwan. The new species is differentiated from five other closely related species, namely T. bitubercularis (Lamarck), T. jubilaea Tan and Sigurdsson, T. clavigera (K黶ter), T. luteostoma (Holten) and T. rufotincta Tan and Sigurdsson, all of which occur in the South China Sea, on the basis of shell, radula and penis morphology. Thais keluo is also distinguished from the latter three species based on allozyme electrophoresis. The shell of T. keluo is characterized by four raised, spiral bands on the last whorl, one or two small, oblique columellar plica(e) on the inner lip, a finely crenate, thin, narrow, reddish-brown outer lip edge and four white, papillate denticles inside the outer lip of the aperture. In males, the penis is curved with a long, simple flagellum. The UPGMA cluster analysis based on 9 enzyme loci revealed that T. luteostoma is more closely related to T. clavigera than to T. keluo n.sp. The Nei's genetic distance (D) obtained between the new species and T. clavigera/T. luteostoma was 0.31, while T. clavigera and T. luteostoma were separated by a distance of 0.16. Thais rufotincta was separated from the other species by a distance of 0.78. In contrast, phylogenetic analysis of morphological data by maximum parsimony suggested that T. luteostoma was more closely related to T. keluo than to T. clavigera. However, both analyses indicated the close relationship amongst T. clavigera, T. luteostoma and the new species in relation to T. rufotincta. PMID:11911084

  5. DOI 10.1007/s00300-010-0889-6 A new species of Armodoris (Mollusca, Gastropoda,

    E-print Network

    Moran, Amy L.

    the continent approximately 84 km from McMurdo Station. At CEW, animals were found crawling on rock surfaces in a boulder Weld starting at approximately 25 m depth and continuing to at least 40 m. At NH, animals were

  6. First report of Angiostrongylus cantonensis (Nematoda: Metastrongylidae) in Achatina fulica (Mollusca: Gastropoda) from Southeast and South Brazil.

    PubMed

    Maldonado Jr, Arnaldo; Sim鮡s, Raquel O; Oliveira, Ana Paula M; Motta, Esther M; Fernandez, M鬾ica A; Pereira, Zilene M; Monteiro, Simone S; Torres, Eduardo J Lopes; Thiengo, Silvana Carvalho

    2010-11-01

    The rat lungworm Angiostrongylus cantonensis is a worldwide-distributed zoonotic nematode that can cause human eosinophilic meningoencephalitis. Here, for the first time, we report the isolation of A. cantonensis from Achatina fulica from two Brazilian states: Rio de Janeiro (specifically the municipalities of Barra do Pira, situated at the Paraiba River Valley region and S鉶 Gon鏰lo, situated at the edge of Guanabara Bay) and Santa Catarina (in municipality of Joinville). The lungworms were identified by comparing morphological and morphometrical data obtained from adult worms to values obtained from experimental infections of A. cantonensis from Pernambuco, Brazil, and Akita, Japan. Only a few minor morphological differences that were determined to represent intra-specific variation were observed. This report of A. cantonensis in South and Southeast Brazil, together with the recent report of the zoonosis and parasite-infected molluscs in Northeast Brazil, provide evidence of the wide distribution of A. cantonensis in the country. The need for efforts to better understand the role of A. fulica in the transmission of meningoencephalitis in Brazil and the surveillance of molluscs and rodents, particularly in ports, is emphasized. PMID:21120369

  7. Grazing under experimental hypercapnia and elevated temperature does not affect the radula of a chiton (Mollusca, Polyplacophora, Lepidopleurida).

    PubMed

    Sigwart, Julia D; Carey, Nicholas

    2014-12-01

    Chitons (class Polyplacophora) are benthic grazing molluscs with an eight-part aragonitic shell armature. The radula, a serial tooth ribbon that extends internally more than half the length of the body, is mineralised on the active feeding teeth with iron magnetite apparently as an adaptation to constant grazing on rocky substrates. As the anterior feeding teeth are eroded they are shed and replaced with a new row. The efficient mineralisation and function of the radula could hypothetically be affected by changing oceans in two ways: changes in seawater chemistry (pH and pCO2) may impact the biomineralisation pathway, potentially leading to a weaker or altered density of the feeding teeth; rising temperatures could increase activity levels in these ectothermic animals, and higher feeding rates could increase wear on the feeding teeth beyond the animals' ability to synthesise, mineralise, and replace radular rows. We therefore examined the effects of pH and temperature on growth and integrity in the radula of the chiton Leptochiton asellus. Our experiment implemented three temperature (?10, 15, 20 癈) and two pCO2 treatments (?400 ?atm, pH 8.0; ?2000 ?atm, pH 7.5) for six treatment groups. Animals (n = 50) were acclimated to the treatment conditions for a period of 4 weeks. This is sufficient time for growth of ca. 7-9 new tooth rows or 20% turnover of the mineralised portion. There was no significant difference in the number of new (non-mineralised) teeth or total tooth row count in any treatment. Examination of the radulae via SEM revealed no differences in microwear or breakage on the feeding cusps correlating to treatment groups. The shell valves also showed no signs of dissolution. As a lineage, chitons have survived repeated shifts in Earth's climate through geological time, and at least their radulae may be robust to future perturbations. PMID:24923634

  8. Detection and genetic distance of resistant populations of Pseudosuccinea columella (Mollusca: Lymnaeidae) to Fasciola hepatica (Trematoda: Digenea) using RAPD markers

    Microsoft Academic Search

    Aym Fernandez Calienes; Jorge Fraga; Jean-Pierre Pointier; Mary Yong; Jorge Sanchez; Christine Coustau; Alfredo Guti閞rez; Andr Th閞on

    2004-01-01

    Twelve natural populations of Pseudosuccinea columella snails, sampled in the western and central regions of Cuba, were analyzed using the RAPD-PCR technique to screen for resistance to Fasciola hepatica. Ten OPA primers previously shown to produce marker bands for resistance and susceptibility were tested. A new population of P. columella (El Azufre, Pinar del R??o) exhibited the amplification patterns of

  9. Detection and genetic distance of resistant populations of Pseudosuccinea columella (Mollusca: Lymnaeidae) to Fasciola hepatica (Trematoda: Digenea) using RAPD markers.

    PubMed

    Calienes, Aym Fernandez; Fraga, Jorge; Pointier, Jean-Pierre; Yong, Mary; Sanchez, Jorge; Coustau, Christine; Guti閞rez, Alfredo; Th閞on, Andr

    2004-09-01

    Twelve natural populations of Pseudosuccinea columella snails, sampled in the western and central regions of Cuba, were analyzed using the RAPD-PCR technique to screen for resistance to Fasciola hepatica. Ten OPA primers previously shown to produce marker bands for resistance and susceptibility were tested. A new population of P. columella (El Azufre, Pinar del R韔) exhibited the amplification patterns of resistant snails, and its resistant status was confirmed after experimental exposure to miracidia. No genetic variability was detected across or within the susceptible isolates. Similarly, the novel resistant isolate displayed an RAPD profile identical to the profile of two other isolates previously identified as resistant to F. hepatica. However, clear differences in RAPD banding patterns and genetic distance were observed between resistant and susceptible isolates. PMID:15301979

  10. Biomonitoring study of an estuarine coastal ecosystem, the Sacca di Goro lagoon, using Ruditapes philippinarum (Mollusca: Bivalvia).

    PubMed

    Sacchi, Angela; Mouneyrac, Catherine; Bolognesi, Claudia; Sciutto, Andrea; Roggieri, Paola; Fusi, Marco; Beone, Gian Maria; Capri, Ettore

    2013-06-01

    Coastal lagoons are constantly subjected to releases of chemical pollutants, and so organisms may be exposed to such toxicants. This study investigated through a multivariate approach the physiological status of bivalve Ruditapes philippinarum, farmed in Sacca di Goro lagoon. Biomarkers at different levels of biological organization (catalase, superoxide dismutase, genotoxicity, reburrowing behavior) were evaluated at three sites exposed to different environmental conditions. A seasonal trend was observed, and micronucleus frequency was significantly lowest at the relatively pristine reference site. Enzymatic activity toward oxyradicals be quite efficient since variations in responsiveness were not consistent. However, behavioral impairment was observed in reburrowing rates. Sediment concentrations showed low PAH levels and high natural levels of trace metals Cr and Ni. DistLM statistical analysis revealed a non-significant relationship between selected biomarkers and xenobiotics. Therefore other potentially toxic compounds in admixture at low doses may be involved in driving differing spatial distribution of physiological impairment. PMID:23474981

  11. 揊irst abyssal record of Stenosemus exaratus (G.O.燬ars, 1878) (Mollusca, Polyplacophora) in爐he燦orth-Atlantic Ocean

    PubMed Central

    Allcock, Louise; Schwabe, Enrico

    2013-01-01

    Abstract The first proven abyssal record of Stenosemus exaratus (G.O. Sars, 1878) is presented on the basis of an ROV study in the Irish Sea. For the first time in situ images of the species and data on the environmental parameters are provided. PMID:23794838

  12. Karyology of the Antarctic chiton Nuttallochiton mirandus (Thiele, 1906) (Mollusca: Polyplacophora) with some considerations on chromosome evolution in chitons.

    PubMed

    Odierna, Gaetano; Aprea, Gennaro; Barucca, Marco; Biscotti, Maria Assunta; Canapa, Adriana; Capriglione, Teresa; Olmo, Ettore

    2008-01-01

    We describe the karyotype, location of nucleolus-organizing regions (NORs) and heterochromatin distribution and composition in the Antarctic chiton Nuttallochiton mirandus. Specimens had a karyotype of 2n = 32 chromosomes, of which two were microchromosomes. Among macrochromosomes, the elements of the first and fourth pair were bi-armed, the others were telocentric. At least six NOR sites were detected with NOR-FISH, but only four were Ag-NOR-banding-positive. The two microchromosomes were essentially euchromatic, while all macrochromosomes exhibited clear pericentromeric C bands that were found to be AT-rich (being quinacrine- and DAPI-positive) and resistant to digestion with AluI and HaeIII. N. mirandus has the largest number of chromosomes (2n = 32) and telocentric elements (26) of all the chiton species studied to date. The karyological results of our study agree with previous molecular data indicating N. mirandus as a sister taxon of Acanthochitona crinita. The karyotypes of the two species could be related as a result of Robertsonian rearrangements. According to the more parsimonious hypothesis, the former would be the primitive karyotype, although other evolutionary events cannot be ruled out. PMID:18668332

  13. Population structure, dynamics and production of Hydrobia ulvae (Pennant) (Mollusca: Prosobranchia) along an eutrophication gradient in the Mondego estuary (Portugal)

    Microsoft Academic Search

    Ana Isabel Lilleb; Miguel 耼gelo Pardal; Jo鉶 Carlos Marques

    1999-01-01

    Eutrophication in the Mondego estuary gave rise to qualitative changes in the benthic community, involving the replacement of eelgrass, Zostera noltii, by green algae such as Enteromorpha spp. and Ulva sp. It seems reasonable to assume that, through time, such changes may determine a selected new trophic structure. Hydrobia ulvae, a dominant species in terms of abundance and biomass, was

  14. Characterization of nineteen microsatellite markers and development of multiplex PCRs for the wedge clam Donax trunculus (Mollusca: Bivalvia).

    PubMed

    Nant髇, Ana; Arias-P閞ez, Alberto; M閚dez, Josefina; Freire, Ruth

    2014-08-01

    The wedge clam Donax trunculus is an Atlantic-Mediterranean warm-temperate species found from Senegal to the northern coast of France, including the Mediterranean and Black Sea. It is commercially exploited in several European countries and constitutes an important fishing resource due to its high economical value. To contribute to its conservation and management, nineteen microsatellite markers were isolated from two enriched genomic libraries. These loci were characterized in 30 clams from a single population from northwest Spain. The number of alleles per locus ranged from 2 to 17 and observed and expected heterozygosity varied from zero to 0.714 and from 0.078 to 0.950, respectively. Linkage disequilibrium was not detected and nine loci were in agreement with Hardy-Weinberg equilibrium. Fifteen polymorphic markers were arranged into three multiplex PCR sets to reduce both time and cost of microsatellite genotyping. This is the first time that polymorphic microsatellite markers have been reported for D. trunculus. These new markers provide a valuable resource for future population genetics studies and management and culture of this species. PMID:24852303

  15. Where抯 Waldo? A new commensal species, Waldo arthuri (Mollusca, Bivalvia, Galeommatidae), from爐he燦ortheastern Pacific Ocean

    PubMed Central

    Valentich-Scott, Paul; Foighil, Diarmaid; Li, Jingchun

    2013-01-01

    Abstract A galeommatid bivalve mollusk, representing a new species, is described from off the coasts of California and Vancouver Island, British Columbia. The new bivalve has a commensal relationship with the heart urchin, Brisaster latifrons. It has been observed crawling between the oral spines of this urchin, frequently near the peristome. The bivalve has been recorded from 80 (Vancouver Island) to 444 (southern California) meters depth, in muddy sediments. In common with other galeommatoideans, the new species broods its young; however it differs from the large majority of commensal members in lacking planktotrophic larval development. Waldo arthuri, new species, has multiple morphological, ecological and developmental similarities to other members of the genus Waldo Nicol, 1966, from the southern Atlantic and Antarctic Oceans. This is most pronounced for the Argentine species, Waldo paucitentaculatus Zelaya & Ituarte, 2013, Waldo arthuri抯 sister speciesin nuclear and mitochondrial gene trees. Despite this close relationship, Waldo arthuri is phylogentically distinct and possesses several hinge, shell sculpture, foot, and mantle tentacle characteristics that merit its description as new. PMID:23878515

  16. Study on sequences of ribosomal DNA internal transcribed spacers of clams belonging to the Veneridae family (Mollusca: Bivalvia).

    PubMed

    Cheng, Han-Liang; Xia, De-Quan; Wu, Ting-Ting; Meng, Xue-Ping; Ji, Hong-Ju; Dong, Zhi-Guo

    2006-08-01

    The first and second internal transcribed spacer (ITS1 and ITS2) regions of the ribosomal DNA from four species, Meretrix meretrix L., Cyclina sinensis G., Mercenaria mercenaria L., and Protothaca jedoensis L., belonging to the family Veneridae were amplified by PCR and sequenced. The size of the ITS1 PCR amplification product ranged from 663 bp to 978 bp, with GC contents ranging from 60.78% to 64.97%. The size of the ITS1 sequence ranged from 585 bp to 900 bp, which is the largest range reported thus far in bivalve species, with GC contents ranging from 61.03% to 65.62%. The size of the ITS2 PCR amplification product ranged from 513 bp to 644 bp, with GC contents ranging from 61.29% to 62.73%. The size of the ITS2 sequence ranged from 281 bp to 412 bp, with GC contents ranging from 65.21% to 67.87%. Extensive sequence variation and obvious length polymorphisms were noted for both regions in these species, and sequence similarity of ITS2 was higher than that of ITS1 across species. The complete sequences of 5.8S ribosomal RNA gene were obtained by assembling ITS1 and ITS2 sequences, and the sequence length in all species was 157 bp. The phylogenetic tree of Veneridae clams was reconstructed using ITS2-containing partial sequences of both 5.8S and 28S ribosomal DNA as markers and the corresponding sequence information in Arctica islandica as the outgroup. Tree topologies indicated that P. jedoensis shared a close relationship with M. mercenaria and C. sinensis, a distant relationship with other species. PMID:16939004

  17. Hysterothylacium larvae (Nematoda, Anisakidae) in the freshwater mussel Diplodon suavidicus (Lea, 1856) (Mollusca, Unioniformes, Hyriidae) in Aripuan River, Amazon, Brazil.

    PubMed

    Lopes, Luiza P C; Pimp鉶, Daniel M; Takemoto, Ricardo M; Malta, Jos C O; Varella, Angela M B

    2011-03-01

    Larvae of Hysterothylacium use various invertebrates as intermediate hosts. Definite hosts include fish, birds, reptiles or marine mammals. This study describes the occurrence of Hysterothylacium (Nematoda, Anisakidae) larvae parasitizing the pericardic cavity of Diplodon suavidicus (Unioniformes, Hyriidae) specimens collected in the Amazon basin, Brazil. This is the first record of this nematode parasitizing freshwater bivalves in South America. The high prevalence, medium intensity and medium abundance suggest that D. suavidicus acts as intermediate host for Hysterothylacium species in that environment. PMID:21145894

  18. Mitochondrial and nuclear DNA analysis revealed a cryptic species and genetic introgression in Littorina sitkana (Mollusca, Gastropoda).

    PubMed

    Azuma, Noriko; Yamazaki, Tomoyasu; Chiba, Susumu

    2011-12-01

    We investigated mitochondrial and nuclear DNA genotypes in nominal Littorina sitkana samples from 2 localities in Eastern Hokkaido, northern Japan. Our results indicated the existence of cryptic species. In the analysis of partial mitochondrial Cytchrome b gene sequences, haplotypes of L. sitkana samples were monophyletic in a phylogenetic tree with orthologous sequences from other Littorina species, but were apparently separated in 2 clades. One included typical L. sitkana (CBa clade) samples, which formed a clade with an allopatric species, L. horikawai. The other, CBb, was independent from CBa and L. horikawai. Haplotypes of the mitochondrial 16S rRNA gene also separated into 2 clades. We additionally examined intron sequence of the heat shock cognate 70 (HSC70) nuclear gene and identified 17 haplotypes. These were also separated into 2 clades, HSCa and HSCb. Among the examined Hokkaido samples, 60% of individuals were heterozygotes. However, each heterozygote consisted of haplotypes from the same clade, HSCa or HSCb, and no admixture of HSCa and HSCb haplotypes was observed. These results indicate reproductive isolation between the 2 clades. Among the genotyped Hokkaido samples, 93% of individuals had CBa+燞SCa or CBb+燞SCb genotypes, and 7% had CBb+燞SCa genotypes. The discrepancy between the mtDNA and nuclear DNA haplotypes in a few individuals may have been caused by genetic introgression due to past hybridization. PMID:22374127

  19. Experimental and Molecular Study of Cercariae of Clinostomum sp. (Trematoda: Clinostomidae) from Biomphalaria spp. (Mollusca: Planorbidae) in Brazil.

    PubMed

    Pinto, H A; Caffara, M; Fioravanti, M L; Melo, A L

    2015-02-01

    Despite the large number of reports of species of Clinostomum from vertebrate hosts in South America, studies evaluating the molluscan transmitters of these parasites are scarce. In the present study, clinostomatoid cercariae shed from 0.02% (4/17,485) specimens of Biomphalaria spp., collected at the Pampulha reservoir, Belo Horizonte, Minas Gerais, Brazil, were used for experimental infection of Poecilia reticulata . Samples of cercariae from molluscs and metacercariae experimentally obtained from fish were subjected to morphological and molecular analyses and compared with species of Clinostomum reported in the Americas. The cercariae and metacercariae, here identified as Clinostomum sp., present general morphology similar to that reported for Clinostomum marginatum , however, from molecular point of view, differ significantly from North American C. marginatum and other species of Clinostomum reported in South America. These results suggest that the diversity of Clinostomum found in Brazil may be underestimated. Additional studies aimed at molecular characterization of South American species of Clinostomum, including the finding of specimens with sequences similar to that reported for C. marginatum in North America are required. PMID:25090192

  20. Annotated type catalogue of the Megaspiridae, Orthalicidae, and Simpulopsidae (Mollusca, Gastropoda, Orthalicoidea) in the Natural History Museum, London.

    PubMed

    Breure, Abraham S H; Ablett, Jonathan D

    2015-01-01

    The type status is described for 65 taxa of the Orthalicoidea, classified within the families Megaspiridae (14), Orthalicidae (30), and Simpulopsidae (20); one taxon is considered a nomen inquirendum. Lectotypes are designated for the following taxa: Helixbrephoides d'Orbigny, 1835; Simpulopsiscumingi Pfeiffer, 1861; Bulimulus (Protoglyptus) dejectus Fulton, 1907; Bulimusiris Pfeiffer, 1853. The type status of Bulimussalteri Sowerby III, 1890, and Strophocheilus (Eurytus) subirroratus da Costa, 1898 is now changed to lectotype according Art. 74.6 ICZN. The taxa Bulimusloxostomus Pfeiffer, 1853, Bulimusmarmatensis Pfeiffer, 1855, Bulimusmeobambensis Pfeiffer, 1855, and Orthalicuspowissianusvar.niveusPreston 1909 are now figured for the first time. The following taxa are now considered junior subjective synonyms: Bulimusmarmatensis Pfeiffer, 1855 = Helix (Cochlogena) citrinovitrea Moricand, 1836; Vermiculatus Breure, 1978 = Bocourtia Rochebrune, 1882. New combinations are: Kuschelenia (Bocourtia) Rochebrune, 1882; Kuschelenia (Bocourtia) aequatoria (Pfeiffer, 1853); Kuschelenia (Bocourtia) anthisanensis (Pfeiffer, 1853); Kuschelenia (Bocourtia) aquila (Reeve, 1848); Kuschelenia (Bocourtia) badia (Sowerby I, 1835); Kuschelenia (Bocourtia) bicolor (Sowerby I, 1835); Kuschelenia (Bocourtia) caliginosa (Reeve, 1849); Kuschelenia (Bocourtia) coagulata (Reeve, 1849); Kuschelenia (Bocourtia) cotopaxiensis (Pfeiffer, 1853); Kuschelenia (Bocourtia) filaris (Pfeiffer, 1853); Karaindentata (da Costa, 1901); Clathrorthalicusmagnificus (Pfeiffer, 1848); Simpulopsis (Eudioptus) marmartensis (Pfeiffer, 1855); Kuschelenia (Bocourtia) nucina (Reeve, 1850); Kuschelenia (Bocourtia) ochracea (Morelet, 1863); Kuschelenia (Bocourtia) peaki (Breure, 1978); Kuschelenia (Bocourtia) petiti (Pfeiffer, 1846); Clathrorthalicusphoebus (Pfeiffer, 1863); Kuschelenia (Bocourtia) polymorpha (d'Orbigny, 1835); Scholvieniaporphyria (Pfeiffer, 1847); Kuschelenia (Bocourtia) purpurata (Reeve, 1849); Kuschelenia (Bocourtia) quechuarum Crawford, 1939; Quechuasalteri (Sowerby III, 1890); Kuschelenia (Bocourtia) subfasciata Pfeiffer, 1853; Clathrorthalicusvictor (Pfeiffer, 1854). In an addedum a lectotype is being designated for Bulimulus (Drymaeus) interruptusvar.pallidus Preston, 1909. An index is included to all taxa mentioned in this paper and the preceding ones in this series (Breure and Ablett 2011, 2012, 2014). PMID:25632243