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1

Protostomia: Lophotrochozoa: Mollusca Protostomia: Lophotrochozoa: Mollusca  

E-print Network

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

2

Octopus tetricus (Mollusca: Cephalopoda) as an ecosystem engineer  

E-print Network

Octopus tetricus (Mollusca: Cephalopoda) as an ecosystem engineer David Scheel 1, Peter Godfrey; social; population density; denning; aggregation. Octopus tetricus (Mollusca: Cephalopoda) como ingeniero., Godfrey-Smith P., Lawrence M. 2014. Octopus tetricus (Mollusca: Cepha- lopoda) as an ecosystem engineer

Scheel, David

3

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

E-print Network

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

Zardoya, Rafael

4

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

5

Book Review Phylogeny and Evolution of the Mollusca  

E-print Network

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

Zuschin, Martin

6

THE MOLLUSCA OF PORTO RICO. ~ILLIAM HEALEY DALL  

E-print Network

THE MOLLUSCA OF PORTO RICO. BY ~ILLIAM HEALEY DALL AND CHARLES TORREY SIMPSON. 351 #12;CONTENTS............ . · .. .. .. . .. . .. . . . . . . . .. . . . . . . . . . . .. . .. .. . . . .. . . 514 l,,~tion of the plates __ __ 515--516 Index __ __ 517-524 352 #12;THE MOLLUSCA OF PORTO RICO. Geologlcnl Survey, No. 24. List of the marine mollusca Irom American localities between CRpO Hatteras

7

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

PubMed

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

Lundin, K; Schander, C

2001-01-01

8

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

E-print Network

(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

Ruby, Edward G.

9

UNA NUEVA ESPECIE DE STROMANTHE (MARANTACEAE) DE VERACRUZ, MXICO  

Microsoft Academic Search

Stromanthe popolucana is described as a new species of Marantaceae from southern Veracruz, Mexico. It appears to be related to Stromanthe jacquinii (Roem. & Schult.) Kennedy & Nicolson and Stromanthe ramosissima L., from both of which it differs in its smaller petioles, leaves, and fruits, and its much longer peduncles and cymes. It is a species of evergreen tropical rain

Gonzalo Castillo-Campos; Andrew P. Vovides; Mario Vzquez Torres

10

Evolutionary pattern and process within the Vertigo gouldii (Mollusca: Pulmonata, Pupillidae) group of minute North American land snails  

E-print Network

Evolutionary pattern and process within the Vertigo gouldii (Mollusca: Pulmonata, Pupillidae) group a a Department of Biology, University of New Mexico, Castetter Hall, Albuquerque, NM 87131, USA b Mollusca

Bergthorsson, Ulfar

11

Nueva dramaturgia puertorriquea  

E-print Network

ciclo, con sus altas y sus bajas, fue tierra frtil para que muchos autores nos legaran trabajos que hoy son puntales en esta nueva manifestacin. Nuevos Dramaturgos como Walter Rodrguez, Jaime Ruiz Escobar, Antonio Ramrez Cordova, Pedro Santaliz..., Edgar Quiles, Jos Luis Ramos Escobar, Lylel Gonzlez, Antonio Rosario Quiles, entre muchos otros, dejaron consignados en sus obras el latir de una poca agitada, de un Puerto Rico enfermo de muerte por el flagrante ataque contra su identidad. Sus...

Ramos-Perea, Roberto

1986-10-01

12

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

E-print Network

THE UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS December 29, 1988 Paper 121 TAXONOMY AND PALEOBIOLOGY OF SOME MIDDLE CAMBRIAN SCENELLA (CNIDARIA) AND HYOLITHIDS (MOLLUSCA) FROM WESTERN NORTH AMERICA' L. E. Babcock and R. A. Robison... MOLLUSCA Class HYOLITHA Order HYOLITHIDA Family HYOLITHIDAE Nicholson Remarks. The emended family diagnosis of Malinky (1988:219-220) is followed here. The definition of Hyolithes was recently re- vised (Malinky, 1988; see also Malinky, Mapes...

Babcock, Loren E.; Robison, Richard A.

1988-12-29

13

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

PubMed

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

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

2006-03-15

14

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

PubMed Central

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

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

15

The Complete Sequence of the Mitochondrial Genome of the Chamberednautilus (Mollusca: Cephalopoda)  

SciTech Connect

Background: Mitochondria contain small genomes that arephysically separate from those of nuclei. Their comparison serves as amodel system for understanding the processes of genome evolution.Although complete mitochondrial genome sequences have been reported formore than 600 animals, the taxonomic sampling is highly biased towardvertebrates and arthropods, leaving much of the diversity yetuncharacterized. Results: The mitochondrial genome of a cephalopodmollusk, the Chambered Nautilus, is 16,258 nts in length and 59.5 percentA+T, both values that are typical of animal mitochondrial genomes. Itcontains the 37 genes that are typical for animal mtDNAs, with 15 on oneDNA strand and 22 on the other. The arrangement of these genes can bederived from that of the distantly related Katharina tunicata (Mollusca:Polyplacophora) by a switch in position of two large blocks of genes andtranspositions of four tRNA genes. There is strong skew in thedistribution of nucleotides between the two strands. There are an unusualnumber of non-coding regions and their function, if any, is not known;however, several of these demark abrupt shifts in nucleotide skew,suggesting that they may play roles in transcription and/or replication.One of the non-coding regions contains multiple repeats of a tRNA-likesequence. Some of the tRNA genes appear to overlap on the same strand,but this could be resolved if the polycistron were cleaved at thebeginning of the downstream gene, followed by polyadenylation of theproduct of the upstream gene to form a fully paired structure.Conclusions: Nautilus sp. mtDNA contains an expected gene content thathas experienced few rearrangements since the evolutionary split betweencephalopods and polyplacophorans. It contains an unusual number ofnon-coding regions, especially considering that these otherwise often aregenerated by the same processes that produce gene rearrangements. Thisappears to be yet another case where polyadenylation of mitochondrialtRNAs restores what would otherwise bean incompletestructure.

Boore, Jeffrey L.

2005-12-01

16

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

NASA Astrophysics Data System (ADS)

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.

Li, Baoquan; Zhang, Suping; Li, Xinzheng

2005-03-01

17

On the biology and palaeontology of some predators of bivalved mollusca  

Microsoft Academic Search

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

R. M. CARTER

1968-01-01

18

Relatividad Especial o General?  

E-print Network

RESUMEN: En este trabajo se explican los principales errores conceptuales que se fueron introduciendo secuencialmente en el desarrollo de la Teora Especial de la Relatividad (SR). Se da una deduccin simple de las Transformaciones de Lorentz y se resalta cmo una configuracin rgida, repetida por ms de cien aos, conduce al primer error de una cadena, al declararse que las componentes transversales al movimiento, en el sistema de referencia inercial mvil, no se afectan desde un punto de vista relativista, y en base a un presunto postulado de isotropa se asumen iguales a las medidas en el sistema inercial considerado fijo. Ello conduce a que dichas transformaciones sean igualmente erradas. Haciendo uso de la configuracin general de un movimiento inclinado del sistema inercial mvil, respecto ejes coordenados paralelos, se obtienen resultados correctos de las transformaciones de distancia, tiempo y velocidad, que se han dado en llamar Transformaciones Vectoriales de Lorentz (VLT). Con base a estas primeras correcciones dentro de los fundamentos de la SR son definidas la Transformaciones Locales de Lorentz (LLT) lo cual permiti a su vez definir ms completos los conceptos tanto de tiempo local como de magnitudes fsicas locales. El primer error indicado dentro de la SR condujo indirectamente a obtener una errnea definicin del concepto de masa

Relatividad Vectorial Versus; J A Franco-rodrguez

19

Una nueva especie de Weltrichia (Bennettitales) del Jursico Medio de la Formacin Tecomazuchil (Oaxaca, Mxico)  

Microsoft Academic Search

A new species of Weltrichia (Williamsoniaceae: Bennettitales) is described from the Middle Jurassic of Oaxaca. The specimens come from the Tecomazuchil Formation in the Ayuquila region, at the border between the Oaxaca and Puebla states. Fossils are preserved as impressions and compressions, in a fine-grained sublitharenite sequence deposited in a fluvial environment. Preserved diagnostic characters include: large size; a cup-shaped

Alicia Silva Pineda; Mara Patricia Velasco de Len; Javier Arellano Gil; Juan Ramn Grimaldo

20

UNA NUEVA ESPECIE DE PROCTOPORUS (SAURIA: GYMNOPHTHALMIDAE) DE LOS ANDES DE VENEZUELA  

Microsoft Academic Search

A new species is described of lizard of the genus Proctoporus, belonging to the P. luctuosus group and closely related whith P. achlyens and P. shrevei, from the Cordillera de la Costa de Venezuela and Trinidad Island respectively. This species, an inhabitant in the terminal branches of the Cordillera de Mrida South of the Depresin de Barquisimeto, is the first

Juan Elas GARCIA-PEREZ; Enrique Elas YUSTIZ

21

Especies nuevas de abejas de Cuba y La Espaola (Hymenoptera: Colletidae, Megachilidae, Apidae)  

Microsoft Academic Search

Five new species of Antillean bees are described and illustrated: Colletes granpiedrensis n. sp. (Cuba) (Colletidae) is charaterized as follows: Head and mesosoma black, legs and metasoma brown. Dense brown hairs on head and mesosoma; white on frons and metasomal terga. Clypeus, frons and mesosoma with large punctures, lesser on vertex and metasoma. Malar space more wide than long. Male

Julio A. Genaro

22

Melvin Mndez: Una nueva dramaturgia costarricense  

E-print Network

FALL 1991 141 Melvin Mndez: Una nueva dramaturgia costarricense Pedro Bravo-Elizondo Melvin Mndez (1958) realiz su carrera de actuacin en la Escuela de Teatro de la Universidad de Costa Rica. En 1980 obtuvo el Premio Nacional como mejor...

Bravo-Elizondo, Pedro

1991-10-01

23

The complete sequence of the mitochondrial genome of Nautilus macromphalus (Mollusca: Cephalopoda)  

PubMed Central

Background Mitochondria contain small genomes that are physically separate from those of nuclei. Their comparison serves as a model system for understanding the processes of genome evolution. Although complete mitochondrial genome sequences have been reported for more than 600 animals, the taxonomic sampling is highly biased toward vertebrates and arthropods, leaving much of the diversity yet uncharacterized. Results The mitochondrial genome of the bellybutton nautilus, Nautilus macromphalus, a cephalopod mollusk, is 16,258 nts in length and 59.5% A+T, both values that are typical of animal mitochondrial genomes. It contains the 37 genes that are almost universally found in animal mtDNAs, with 15 on one DNA strand and 22 on the other. The arrangement of these genes can be derived from that of the distantly related Katharina tunicata (Mollusca: Polyplacophora) by a switch in position of two large blocks of genes and transpositions of four tRNA genes. There is strong skew in the distribution of nucleotides between the two strands, and analysis of this yields insight into modes of transcription and replication. There is an unusual number of non-coding regions and their function, if any, is not known; however, several of these demark abrupt shifts in nucleotide skew, and there are several identical sequence elements at these junctions, suggesting that they may play roles in transcription and/or replication. One of the non-coding regions contains multiple repeats of a tRNA-like sequence. Some of the tRNA genes appear to overlap on the same strand, but this could be resolved if the polycistron were cleaved at the beginning of the downstream gene, followed by polyadenylation of the product of the upstream gene to form a fully paired structure. Conclusion Nautilus macromphalus mtDNA contains an expected gene content that has experienced few rearrangements since the evolutionary split between cephalopods and polyplacophorans. It contains an unusual number of non-coding regions, especially considering that these otherwise often are generated by the same processes that produce gene rearrangements. The skew in nucleotide composition between the two strands is strong and associated with the direction of transcription in various parts of the genomes, but a comparison with K. tunicata implies that mutational bias during replication also plays a role. This appears to be yet another case where polyadenylation of mitochondrial tRNAs restores what would otherwise be an incomplete structure. PMID:16854241

Boore, Jeffrey L

2006-01-01

24

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

Microsoft Academic Search

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

Leonid Moroz; Leonid Nezlin; Rolf Elofsson; Dmitri Sakharov

1994-01-01

25

Especially for High School Teachers  

NASA Astrophysics Data System (ADS)

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

Howell, J. Emory

1999-05-01

26

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

PubMed

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 Limn 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

Garca-Ros, Cedar I; Alvarez-Ruiz, Migdalia

2011-03-01

27

Especially for High School Teachers  

NASA Astrophysics Data System (ADS)

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, Whler, 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 LeChtelier'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

Howell, J. Emory

2000-01-01

28

Especially for High School Teachers  

NASA Astrophysics Data System (ADS)

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,

Howell, J. Emory

1999-06-01

29

Especially for High School Teachers  

NASA Astrophysics Data System (ADS)

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 &

Howell, J. Emory

1999-07-01

30

Especially for High School Teachers  

NASA Astrophysics Data System (ADS)

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

Howell, J. Emory

1999-09-01

31

Deux espces sous un mme masque. Le point de vue palontologique pig par les coquilles de deux espces europennes de Trivia (Mollusca, Gastropoda)  

Microsoft Academic Search

Two species behind the same mask. The palaeontological approach caught out by two European species of Trivia (Mollusca, Gastropoda).- The experiment reported in this paper was devised to assess to what extent loss of information as a result of fossilization might affect species discrimination in palaeontology. The test consisted in first conducting a \\

Elisabeth DOMMERGUES; Jean-Louis DOMMERGUES; Cyril Hugues DOMMERGUES

2006-01-01

32

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

PubMed

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

Pimenta, Alexandre Dias; Monteiro, Jlio Csar; Barbosa, Andr Favaretto; Salgado, Norma Campos; Coelho, Arnaldo Campos Dos Santos

2014-01-01

33

Hard and soft anatomy in two genera of Dondersiidae (Mollusca, Aplacophora, Solenogastres).  

PubMed

Phylogenetic relationships and identifications in the aplacophoran taxon Solenogastres (Neomeniomorpha) are in flux largely because descriptions of hard parts--sclerites, radulae, copulatory spicules--and body shape have often not been adequately illustrated or utilized. With easily recognizable and accessible hard parts, descriptions of Solenogastres are of greater use, not just to solenogaster taxonomists, but also to ecologists, paleontologists, and evolutionary biologists. Phylogenetic studies of Aplacophora, Mollusca, and the Lophotrochozoa as a whole, whether morphological or molecular, would be enhanced. As an example, morphologic characters, both isolated hard parts and internal anatomy, are provided for two genera in the Dondersiidae. Five species are described or redescribed and earlier descriptions corrected and enhanced. Three belong to Dondersia: D. festiva Hubrecht, D. incali (Scheltema), and D. namibiensis n. sp., the latter differentiated unambiguously from D. incali only by sclerites and copulatory spicules. Two species belong to Lyratoherpia: L. carinata Salvini-Plawen and L. californica (Heath). Notes are given for other species in Dondersiidae: L. bracteata Salvini-Plawen, Ichthyomenia ichthyodes (Pruvot), and Heathia porosa (Heath). D. indica Stork is synonymized with D. annulata. A cladistic morphological analysis was conducted to examine the utility of hard parts for reconstructing solenogaster phylogeny. Results indicate monophyly of Dondersia and Lyratoherpia as described here. PMID:22815372

Scheltema, Amlie H; Schander, Christoffer; Kocot, Kevin M

2012-06-01

34

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

PubMed Central

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

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

2011-01-01

35

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

PubMed

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

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

2011-07-01

36

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

E-print Network

crean redes, pero esas redes necesitan vender algo, transportarlo y entregarlo al cliente o al coste, de mayor productividad y de mayor rentabilidad) la creación de las nuevas redes de información, al final, a colonizar dichas redes y afianzarse aún más en sus sectores productivos generando menores

Bilbao Arrese, Jesús Mario

37

Volutidae (Mollusca: Gastropoda) of the Lakhra Formation (Earliest Eocene, Sindh, Pakistan): systematics, biostratigraphy and paleobiogeography.  

PubMed

The paleobiodiversity of the Volutidae (Mollusca: Gastropoda) of the Ranikot Group (Sindh, Pakistan) and particularly of the Lakhra Formation (SBZ 5 biozone, Earliest Eocene), is reconsidered on the basis of new material collected during recent field trips. Ten new species are described (Mitreola brohii sp. nov., Lyrischapa vredenburgi sp. nov., L. brevispira sp. nov., Athleta (Volutopupa) citharopsis sp. nov., A. (Volutocorbis) lasharii sp. nov., Volutilithes welcommei sp. nov., V. sindhiensis sp. nov., Pseudaulicina coxi sp. nov., Sindhiluta lakhraensis sp. nov. and Pakiluta solangii sp. nov.) and one species is in open nomenclature (Lyria sp.). Three new genera are described: Lyriopsis gen. nov. [Volutinae, ?Lyriini, type species: Lyriopsis cossmanni (Vredenburg, 1923)], Sindhiluta gen. nov. [Volutilithinae, type species: Sindhiluta lakhraensis n. sp.] and Pakiluta gen. nov. [?Volutodermatinae, type species: Pakiluta solangii n. sp.]. Two new combinations are proposed: Lyriopsis cossmanni (Vredenburg, 1923) comb. nov. and Athleta (Volutopupa) intercrenatus (Cossmann & Pissarro, 1909) comb. nov. Lectotypes are designated for Lyria cossmanni Vredenburg, 1923, L. feddeni Vredenburg, 1923, Volutospina noetlingi Cossmann & Pissarro, 1909, V. intercrenata Cossmann & Pissarro, 1909 and Athleta (Volutocorbis) victoriae Vredenburg, 1923. With 21 species, this volutid fauna is the most diverse recorded from the Tethys Ocean during Earliest Eocene time. The assemblage is characterized by a strong turnover marked by regional speciation and the appearance of many western Tethyan invaders. Although at the species level, the assemblage documents a strong provincialism, at the genus level, the high number of shared genera between Eastern Tethyan and Old World Tethyan realms begins a phase of long-term homogeneity of volutid assemblages from the Tethyan paleobiogeographic province. PMID:24990040

Merle, Didier; Pacaud, Jean-Michel; Mtais, Grgoire; Bartolini, Annachiara; Lashari, Rafiq A; Brohi, Imdad A; Solangi, Sarfraz H; Marivaux, Laurent; Welcomme, Jean-Loup

2014-01-01

38

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

NASA Astrophysics Data System (ADS)

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.

Checa, Antonio G.; Ramrez-Rico, Joaqun; Gonzlez-Segura, Alicia; Snchez-Navas, Antonio

2009-01-01

39

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

USGS Publications Warehouse

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.

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

1993-01-01

40

The Evolution of Cooperation, Especially in Humans  

E-print Network

The Evolution of Cooperation, Especially in Humans Submitted for the Degree of Doctor of Philosophy by policing. 66 Chapter 4. Group competition and the evolution of cooperation in humans. 98 Chapter 5. Chapter 5 is in review at Evolution and Human Behaviour as a research paper. I had the original idea

Gardner, Andy

41

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

PubMed

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

Tunholi-Alves, Vincius Menezes; Tunholi, Victor Menezes; Amaral, Ludimila Santos; Mota, Esther Maria; Jnior, Arnaldo Maldonado; Pinheiro, Jairo; Garcia, Juberlan

2015-01-01

42

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

PubMed

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

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

2014-11-01

43

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

E-print Network

Aulas Informáticas de libre acceso (Informática, nuevas tecnologías y redes sociales) INTRODUCCI?N) Centro de Tecnología Química-CTQ (código situación 41) . REDES SOCIALES EN LA UA BLOGS.UA.ES LA UA EN LAS REDES SOCIALES (TWITTER y FACEBOOK) AYUDA Y FORMACI?N EN LAS NUEVAS TECNOLOGÍAS DE LA INFORMACI?N Y LA

Escolano, Francisco

44

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

PubMed Central

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 g 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

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

2014-01-01

45

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

E-print Network

La ciencia del lenguaje estudia el fenómeno de las TIC, redes sociales y nuevas formas de comunicación 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 comunicación" comienza el lunes 11 de marzo de 2013 y hasta

Escolano, Francisco

46

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

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

47

High level of activation Coupled product is very stable, especially  

E-print Network

for pharmaceutical companies producing therapeutic products, especially those working with synthetic peptides between matrix and activated group is especially suitable for immobilising small proteins and peptides protein and peptide ligands. The advantages of high stability and a spacer arm combined with the high flow

Lebendiker, Mario

48

V SEMINARIO HISPANO-ARGENTINO: Los discursos sobre la Ciencia y las Nuevas Tecnologas en la Sociedad del Conocimiento  

E-print Network

V SEMINARIO HISPANO-ARGENTINO: Los discursos sobre la Ciencia y las Nuevas Tecnologías en la Universidad Nacional del Litoral (Argentina), se centra este año en los "Discursos sobre la Ciencia y las procede, esta vez centrando la atención en el discurso de la ciencia y de las nuevas tecnologías. Se

Escolano, Francisco

49

2. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 1) ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 1) FROM THE 'CAMPUS' GROUNDS; LOOKING SW. (Harms) - Veterans Administration Medical Center, Old State Route 13 West, Marion, Williamson County, IL

50

3. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 2 ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 2 & BUILDING 1) FROM THE 'CAMPUS' GROUNDS; LOOKING NW. (Harms) - Veterans Administration Medical Center, Old State Route 13 West, Marion, Williamson County, IL

51

4. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 2 ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 2 & BUILDING 1) FROM THE 'CAMPUS' GROUNDS; LOOKING NE. (Harms) - Veterans Administration Medical Center, Old State Route 13 West, Marion, Williamson County, IL

52

The Beam Application to Nanoscience, Especially Next Generation Lithography  

NASA Astrophysics Data System (ADS)

The beam application to nanoscience, especially next generation lithography producing the semiconductor devices, is expanded by so-called quantum beam technology. EUV (Extreme Ultraviolet) lithography is now evaluated to be the best solution of the next generation lithography for 22 nm node and beyond 22 nm node. Recent progress in the development of EUV lithography, especially resist processes and materials, is supported by many kinds of beam technology such as pulse radiolysis.

Tagawa, Seiichi

53

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

E-print Network

INTERNET 2 : Las nuevas redes del futuro Juan Manuel Torres Moreno Laboratorio Nacional de más virtual) pero aún mas impactante: la revolución de las redes de computadoras. Internet ha supuesto idea de federar varias redes que usaran la conmutación de paquetes y un protocolo de enlace llamado NCP

Avignon et des Pays de Vaucluse, Université de

54

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 Introducción La mosca Drosophila de alas manchadas (Drosophila mayoría de las moscas del vinagre atacan cuando la fruta esta dañada. A diferencia de estas, la Drosophila

55

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

PubMed Central

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

2014-01-01

56

different Drosophila species, especially those that are specialized for specific  

E-print Network

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

VanRullen, Rufin

57

Complete mitochondrial genome of Coelomactra antiquata (Mollusca: Bivalvia): The first representative from the family Mactridae with novel gene order and unusual tandem repeats.  

PubMed

The complete mitochondrial genome plays an important role in the accurate inference of phylogenetic relationships among metazoans. Mactridae, also known as trough shells or duck clams, is an important family of marine bivalve clams in the order Veneroida. Here we present the complete mitochondrial genome sequence of the Xishishe Coelomactra antiquata (Mollusca: Bivalvia), which is the first representative from the family Mactridae. The mitochondrial genome of C. antiquata is of 17,384bp in length, and encodes 35 genes, including 12 protein-coding, 21 transfer RNA, and 2 ribosomal RNA genes. Compared with the typical gene content of animal mitochondrial genomes, atp8 and tRNAS(2) are missing. Gene order of the mitochondrial genome of C. antiquata is unique compared with others from Veneroida. In the mitochondrial genome of the C. antiquata, a total of 2189bp of non-coding nucleotides are scattered among 26 non-coding regions. The largest non-coding region contains one section of tandem repeats (99 bp11), which is the second largest tandem repeats found in the mitochondrial genomes from Veneroida. The phylogenetic trees based on mitochondrial genomes support the monophyly of Veneridae and Lucinidae, and the relationship at the family level: ((Veneridae+Mactridae)+(Cardiidae+Solecurtidae))+Lucinidae. The phylogenetic result is consistent with the morphological classification. Meanwhile, bootstrap values are very high (BP=94-100), suggesting that the evolutionary relationship based on mitochondrial genomes is very reliable. PMID:22381378

Meng, Xueping; Zhao, Nana; Shen, Xin; Hao, Jue; Liang, Meng; Zhu, Xiaolin; Cheng, Hanliang; Yan, Binlun; Liu, Zhaopu

2012-06-01

58

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

E-print Network

EL JARDÍN BOTÁNICO DE NUEVA YORK POLÍTICA DE ADQUISICIONES DEL DEP?SITO DE ADN El depósito de ADN y de ADN genómico para investigaciones conducidas por científicos, estudiantes de post misión del Jardín para documentar la biodiversidad, la meta del depósito de ADN es almacenar muestras de

Law, Wayne

59

FALSO ESTUDIO PARTES MANTENIMIENTO AO 2011 SERVICIO EXTERNALIZADO-Acondicionado(nueva  

E-print Network

/VozDatos (reparación) Teléfonos(averias) Teléfonos(nueva Instalación) Vidrios Totalgeneral ACCESOS, ZONAS COMUNES Y OTROS 0 8 80 0 16 0 25 0 0 34 3 6 3 18 0 1 23 2 1 0 19 49 6 5 5 7 3 1 315 2,54% ACCESOS, ZONAS COMUNES Y ESCUELA POLIT?CNICA SUPERIOR IV 1 30 12 0 74 9 67 0 0 56 1 51 2 42 2 3 2 5 5 1 52 7 15 10 8 19 9 4 487 3

Escolano, Francisco

60

Toxic Effects of Fluoride Ion on Survival, Reproduction and Behaviour of the Aquatic Snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca)  

Microsoft Academic Search

Inorganic fluoride concentrations in aquatic ecosystems have been significantly increased by several human activities during\\u000a the last decades. However, there is still relatively scarce information about its toxicity to freshwater animals, especially\\u000a at long-term exposures. The aim of our study is to assess the short-term (4days) and long-term (28days) fluoride (F?) toxicity to the aquatic snail Potamopyrgus antipodarum on the

lvaro Alonso; Julio A. Camargo

2011-01-01

61

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)

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.

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

2011-12-01

62

Loads and antimicrobial resistance of Campylobacter spp. on fresh chicken meat in Nueva Ecija, Philippines.  

PubMed

This study was performed to determine the prevalence and to semiquantify Campylobacterspp. on chicken meat samples at 4 selected local wet markets in Nueva Ecija, Philippines, and to determine the antimicrobial resistance patterns of the Campylobacter isolates. Out of 120 chicken meat samples, 57 (47.5%) were Campylobacter spp. positive. The majority of isolated Campylobacter strains were identified as Campylobacter coli (54.4%) and 45.6% as Campylobacter jejuni. Most of these positive samples (52.6%) showed a very high quantitative Campylobacter contamination (most probable number > 2,400/g, lower confidence limit 580/g). For antimicrobial resistance testing, 44 C. coli/jejuni isolates were tested using the agar disk diffusion method. Out of these, 77.3% were resistant to ampicillin, followed by ciprofloxacin (70.4%), tetracycline (54.6%), erythromycin (20.2%), and gentamicin (11.4%). Of the isolates, 36.4% (n = 16) were resistant to 1 antimicrobial agent, 34.1% (n = 15) were resistance to 3 antimicrobial agents, 13.6% (n = 6) to 2 antimicrobial agents, 9.1% (n = 4) to 4 antimicrobial agents, and 6.8% (n = 3) to all 5 antimicrobial agents tested. Our data demonstrate a high contamination of fresh chicken meat with Campylobacter spp. at retail in the Philippines. The detected high Campylobacter prevalences and quantitative loads on chicken meat at retail in the Philippines highlight the need to implement efficient intervention measures along the food chain and to encourage sanitary handling of poultry meat. PMID:24795322

Sison, F B; Chaisowwong, W; Alter, T; Tiwananthagorn, S; Pichpol, D; Lampang, K N; Baumann, M P O; Glz, G

2014-05-01

63

TURISMO RURAL EN ESPAA: PAISAJES Y USUARIOS, NUEVOS USOS Y NUEVAS VISIONES  

Microsoft Academic Search

This article describes the situation of rural tourism in Spain, especially in Catalonia and Galicia. It is focused on the new leisure and tourism uses of rural spaces, an aspect which is changing and diversifying the rural economies. Related to this, it is described how local inhabitants perceive and reperceive their heritage, their landscapes and their places from the new

Gemma Cnoves Valiente; Luis Herrera Jimnez; Villarino Prez

2005-01-01

64

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 (* ...

65

25 CFR 213.45 - Restrictions especially continued as to certain lands.  

Code of Federal Regulations, 2013 CFR

...BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF RESTRICTED LANDS OF MEMBERS OF FIVE CIVILIZED TRIBES, OKLAHOMA, FOR MINING Removal of Restrictions 213.45 Restrictions especially continued as to certain...

2013-04-01

66

25 CFR 213.45 - Restrictions especially continued as to certain lands.  

Code of Federal Regulations, 2010 CFR

...BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF RESTRICTED LANDS OF MEMBERS OF FIVE CIVILIZED TRIBES, OKLAHOMA, FOR MINING Removal of Restrictions 213.45 Restrictions especially continued as to certain...

2010-04-01

67

Synthetic Marijuana Lands Thousands of Young People in the ER, Especially Young Males  

MedlinePLUS

... People in the ER, Especially Young Males Synthetic Marijuana Lands Thousands of Young People in the ER, ... on the scene a few years ago, synthetic marijuana (MJ)often called Spice or K2has become ...

68

A STUDY OF' TWIN LAKES, COLORADO, WITH ESPECIAL CONSIDERATION OF THE FOOD OF THE TROUTS.  

E-print Network

. _ __ ..·. _.. __ . _.... __ ; .. . .. _... _ __ .. Mackinaw trout _.. __ .. _.·....... _ __ . -. . __ .. __ .. Small brook trout _.......· _ __ __ . _ .. _. _. Large brook trout, . _. _ _ _.. _ _. _ .. _ ...........·.. FryA STUDY OF' TWIN LAKES, COLORADO,· WITH ESPECIAL CONSIDERATION OF THE FOOD OF THE TROUTS

69

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

E-print Network

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

Walz, Thomas

70

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

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.

Hoy, Marshal S.; Rodriguez, Rusty J.

2013-01-01

71

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

E-print Network

sibling species in Nassarius (Mollusca, Prosobranchia) Un ejemplo de aplicación de la herramienta de morfometría geométrica en el diagnóstico morfológico de dos especies gemelas en Nassarius (Mollusca

Carvajal-Rodríguez, Antonio

72

Paraneoplastic downbeat nystagmus associated with cerebellar hypermetabolism especially in the nodulus.  

PubMed

A 52-year-old man with vertigo and imbalance for two weeks showed spontaneous downbeat (DBN), horizontal gaze-evoked, and positional apogeotropic nystagmus along with severe limb and truncal ataxia. Gadolinium-enhanced brain MRI was normal, but whole body and brain 2-deoxy-2-[F18]fluoro-d-glucose-positron emission tomography revealed hypermetabolism in the right lower lobe of the lung and the cerebellum, especially in the nodulus. The lesion in the lung was confirmed as mixed cell carcinoma. Paraneoplastic DBN may be associated with cerebellar hypermetabolism, especially in the nodulus. PMID:24928076

Choi, Seo Young; Park, Seong-Ho; Kim, Hyo-Jung; Kim, Ji-Soo

2014-08-15

73

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

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),

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

2004-01-01

74

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

E-print Network

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

Brown, Christopher A.

75

ll cells contain lots of big molecules, especially proteins, nucleic acids and  

E-print Network

A ll cells contain lots of big molecules, especially proteins, nucleic acids and complex sugars- escent proteins in animal cells -- both within the cytoplasm and inside two cellu- lar compartments consequences that could affect many aspects of cellular function. Yet most bio- chemical studies

Weston, Ken

76

Lobstermen and researchers are engaging in cooperative research, especially to collect `real  

E-print Network

Lobstermen and researchers are engaging in cooperative research, especially to collect `real time'informationonLongIslandSound. Long Island Sound Lobster Research Initiative is a collaboration funded by National Oceanic Shennecossett Road, Groton, CT 06340 860.405.9127 www.seagrant.sunysb.edu/LILobsters LONG ISLAND SOUND Lobster

Allam, Bassem

77

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

E-print Network

© 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 1­2 H+ . This variation is due to the difficulty of having all the enzyme molecules

Braun, Paul

78

Researchers Use RFID to Fight SIDS This system would be especially useful in hospital  

E-print Network

NEWS Researchers Use RFID to Fight SIDS This system would be especially useful in hospital nurseries, Chiao says, since it could send the unique ID number of the baby's crib RFID tag, as well be trained to be familiar with RFID technologies." When the system will be tested there has not yet been

Chiao, Jung-Chih

79

THE INFLUENCE OF LIVESTOCK WATERING PONDS (DUGOUTS) ON NATIVE STREAM FISHES, ESPECIALLY THE ENDANGERED TOPEKA SHINER  

E-print Network

THE ENDANGERED TOPEKA SHINER (Notropis topeka) BY Sheila K. Thomson A thesis submitted in partial fulfillment (Dugouts) on Native Stream Fishes, Especially the Endangered Topeka Shiner (Notropis topeka) Sheila K is important for the management of native stream fishes, such as the endangered Topeka shiner (Notropis topeka

80

Counting the notes: Numerology in the works of Mozart, especially Die Zauberflte  

Microsoft Academic Search

A non-standard contribution to Mozart's bicentenary year is made by showing that he was a refined numerologist, especially in the opera Die Zauberflte (1791), but also in some other works of his maturity. An extensive analysis of this opera is furnished, showing that the numerology is evident not only in the structure of the work and the design of melodies

I. Grattan-Guinness

1992-01-01

81

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

E-print Network

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

Kumar, Ratnesh

82

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

E-print Network

3 CADERNOS TEMÁTICOS ­ QUÍMICA NOVA NA ESCOLA Edição especial ­ FEVEREIRO 2001 E ste volume é uma nova ordem. A informação transformou nos- so planeta em um sis- tema único, interli- gado. Quando a avaliação de risco ambiental, com o risco de exposi- ção às novas moléculas produzidas pelo homem, das quais

Jardim, Wilson de Figueiredo

83

El Instituto Nacional del Cncer (NCI) anuncia su nueva poltica de reuniones libres de humo de tabaco para abordar peligros graves de salud pblica  

Cancer.gov

El Instituto Nacional del Cncer (NCI), que forma parte de los Institutos Nacionales de la Salud, anunci hoy una nueva poltica 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 poltica integral de ambientes libres de humo de tabaco, a menos que circunstancias especificas justifiquen la exencin.

84

Highly efficient tetradentate ruthenium catalyst for ester reduction: especially for hydrogenation of Fatty Acid esters.  

PubMed

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

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

2015-02-01

85

A microwave heating technique for the hyperthermic treatment of tumours in the eye, especially retinoblastoma.  

PubMed

A special microwave stripline applicator (2450 MHz) has been designed for the hyperthermic treatment of eye tumours, especially retinoblastoma. The measured microwave absorbed power distribution was put into a thermal finite difference computer model of the human and rabbit eye to calculate the resulting temperature distributions. The temperature distributions have been experimentally verified on rabbit eyes, and satisfactory temperature distributions can be obtained. The anterior part as well as the posterior part of the eye can be heated uniformly to temperatures in the range of 37-44 degrees C. The complete hyperthermia system is described. PMID:7178233

Lagendijk, J J

1982-11-01

86

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

NASA Technical Reports Server (NTRS)

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.

Ebner, Hans

1938-01-01

87

[Association of sardine fishery, Sardinella aurita (Teleostei: Clupeidae) and environmental variability of the coastal upwelling ecosystem of Nueva Esparta, Venezuela].  

PubMed

The present research is an analysis of Spanish sardine fishing (Sardinella aurita) associated with some climatic and meteorologic parameters of the ecosystem from El Morro Nueva Esparta, Venezuela. The catch and environmental data from the area were taken in the period 1996-2000. Catch data as a function of wind speed, sea surface temperature, air temperature and rain were analyzed by means of simple lineal regression and multiple models. We found a positive correlation of catch with wind speed, and a negative correlation with sea surface temperature, air temperature, and rain. The multiple regression model with intercept had a poor fit, therefore, we made a model without intercept, which improve greatly the fit. A selection of the variables using the forward procedure verified that the independent variables "wind speed" and "air temperature" have a significant relation with catch (p < 0.001) at real time. This method suggests that sea surface temperature and rain have little influence on the catch, and suggests a major availability of resources in the months with low air temperature and the highest wind speed (January-June). Rev. PMID:18457137

Gonz?lez, Leo W; Eun, Jorge; Eslava, Nora; Suniaga, Jess

2007-03-01

88

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

PubMed

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

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

2012-03-01

89

Differential diagnostic assays for discriminating mycobacteria, especially for nontuberculous mycobacteria: what does the future hold?  

PubMed

ABSTRACT Mycobacteria infections are an important medical problem, and many are regarded as emerging and re-emerging diseases. Mycobacterium tuberculosis, the causative agent of tuberculosis, remains a leading cause of human morbidity and mortality worldwide, with approximately 8.6 million cases and 1.3 million deaths in 2012. In addition, the incidence of nontuberculous Mycobacterium infection has significantly increased, especially among developed countries. Although phenotypical appearances such as culture characteristics and/or susceptibility to anti-Mycobacterium drugs are variable between different mycobacterial species, early diagnosis is crucial in terms of patient treatment and clinical outcome. In this manuscript, we describe the development of diagnostic techniques, from the classical/conventional to the most recent advances, and provide an overview of the future direction of discrimination procedures. PMID:25689533

Hoshino, Yoshihiko; Suzuki, Koichi

2015-02-01

90

Clinical experience with titanium implants, especially with the limited contact dynamic compression plate system.  

PubMed

AO/ASIF with its collaborating laboratories has developed cold worked pure titanium material for implants with an outstanding biocompatibility. The first prospectively controlled clinical series dates back to 1966 and was reported to be most successful. Pure titanium also became the material of choice for implants to be used in patients suffering from metal allergy. Today, a long-term and well-documented experience with these implants exists. It therefore seemed logical to use pure titanium for the new limited contact dynamic compression plate (LC-DCP) system described in the previous article by Perren. Pilot clinics started to implant titanium LC-DCP in 1987, and already 271 plates have been used, mainly for the treatment of fresh fractures. Some 57 plates have so far been removed. The preliminary results are most favourable; they confirm especially the outstanding biocompatibility of pure titanium. PMID:2073448

Matter, P; Burch, H B

1990-01-01

91

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

SciTech Connect

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.

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

92

Universidade Federal do Rio de Janeiro Instituto de Biologia  

E-print Network

: MOLLUSCA 06/fev Lophophorata 07/fev 11/fev Annelida 14/fev Annelida 18/fev Annelida 21/fev Annelida 25/fev Annelida 28/fev Annelida 11/mar Annelida 14/mar Annelida 18/mar Avaliação Annelida 21/mar Mollusca 25/mar Mollusca 28/mar Mollusca 01/abr Mollusca 04/abr Mollusca 08/abr Mollusca 11/abr Mollusca 15/abr Mollusca 18

Paiva, Paulo Cesar de

93

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

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

Gosliner, Terrence M; Fahey, Shireen J

2011-01-01

94

Microalbuminuria: a common, independent cardiovascular risk factor, especially but not exclusively in type 2 diabetes.  

PubMed

Microalbuminuria (defined as an albumin-creatinine ratio of 10-25 mg/mmol on the first-morning urine sample, or an albumin excretion rate of 20-200 microg/min on a timed collection) is present in 20-30% of all patients with type 2 diabetes, and is especially common in those with hypertension, endothelial dysfunction and other features of insulin resistance. Although microalbuminuria is predictive of worsening microvascular disease in the kidney (5-10% per year progress to overt diabetic nephropathy), an increased albumin excretion rate (AER) reflects a generalized abnormality of vascular function and is associated with 2-4-fold increases in cardiovascular and all-cause mortality. The extent to which microalbuminuria is a risk factor independent of other variables in type 2 diabetes, e.g. blood pressure and smoking, has been highlighted by recent cohort studies, e.g. the Heart Outcome Prevention Evaluation study and the Wisconsin Epidemiological Study of Diabetic Retinopathy. In the former study, for example, microalbuminuria at baseline increased the adjusted relative risks (RR) of a major cardiovascular event (RR 1.83), all-cause death (RR 2.09) and hospitalization for heart failure (RR 3.23) in both diabetic and non-diabetic subjects. These studies also highlighted that AER is a continuous risk factor, and that levels of AER below the arbitrary threshold for defining microalbuminuria are associated with relatively increased cardiovascular risk. Similarly, microalbuminuria affects 10-15% of middle-aged non-diabetics and is associated with coronary, peripheral and cerebral vascular complications. Detection of microalbuminuria, especially in type 2 diabetes, signifies the need to intensify blood pressure control as part of a multiple risk factor intervention strategy in a high-risk group. As hypertensive patients with type 2 diabetes are frequently treated by more than one antihypertensive agent, ACE inhibitors and low-dose diuretics are preferably recommended in order to provide sufficient blood pressure control and target organ protection. PMID:12769161

Donnelly, Richard; Yeung, Justin M C; Manning, Gillian

2003-03-01

95

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

NASA Astrophysics Data System (ADS)

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.

Mascart, Thibaud; Lepoint, Gilles; Deschoemaeker, Silke; Binard, Marc; Remy, Franois; De Troch, Marleen

2015-01-01

96

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

USGS Publications Warehouse

de esta especie de un modo ms 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.

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

1999-01-01

97

Genetic biases for showy males: Are some genetic systems especially conducive to sexual selection?  

PubMed Central

Male secondary sexual characters (conspicuous ornaments, signals, colors) are among nature's most striking features. Yet, it is unclear why certain groups of organisms are more likely than others to evolve these traits. One explanation for such taxonomic biases is that some genetic systems may be especially conducive to sexual selection. Here, we present theory and simulation results demonstrating that rare alleles encoding either male ornaments or female preferences for those ornaments are better protected against random loss in species with ZZ/ZW or ZZ/ZO sex chromosome systems (male homogamety) than in species with XX/XY or XX/XO systems (male heterogamety). Moreover, this protection is much stronger in diploid than haplodiploid species. We also present empirical data showing that male secondary sexual characters are better developed in diploid than haplodiploid species and in diploid species with male homogamety than in those with male heterogamety. Thus, taxonomic biases for showy males may stem from differences in sex chromosome systems. PMID:12540829

Reeve, Hudson Kern; Pfennig, David W.

2003-01-01

98

Serum CRP and urinary trypsin inhibitor implicate postoperative cognitive dysfunction especially in elderly patients.  

PubMed

Purpose: Postoperative cognitive dysfunction (POCD) characterized as the decline of memory and executive function after major surgery is not well illustrated. The aim of this study is to discover whether inflammatory cytokines and urinary trypsin inhibitor (uTi) contribute to the development of POCD. Method: Sixty-three patients undergoing lumber discectomy and 47 age-matched control volunteers were involved in this study. The level of C-reaction protein (CRP) and uTi/urine creatinine (Ucr) was measured by immunoturbidimetry and enzyme-inhibition assay, respectively. Meanwhile, ELISA was involved to detect the level of IL-6, IL-10, MMP-9 in serum. Montreal Cognitive Assessment (MoCA) test was used to determine the cognitive decline of the patients and age-matched controls. Result: In POCD group, the level of IL-6, IL-10, CRP, MMP-9 in serum and uTi /Ucr in urine was significantly higher than that in the group without POCD. The POCD was more frequently observed in elderly group than in the middle-aged group (43.75% versus 19.35%, p = 0.038). After logistic regression analysis adjusted by the age, only serum CRP at 72h postoperation and urinary uTi /Ucr at 24h postoperation were the independent risk factors of POCD. Conclusion: Age-related increasing proinflammatory postoperation may result in higher occurrence of POCD in the elderly. Additionally, patients with extremely high concentrations of CRP in serum at 72h postoperation and uTi /Ucr in urine at 24h postoperation are more likely to experience POCD, especially in the elderly. PMID:25105909

Zhang, Yan-Hua; Guo, Xiu-Hai; Zhang, Qing-Ming; Yan, Guang-Tao; Wang, Tian-Long

2014-09-17

99

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

100

Nuevas Adquisiciones (Recent Acquisitions).  

ERIC Educational Resources Information Center

This bibliography of educational materials lists approximately 100 publications recently acquired by the Colombian National Center for Documentation and Educational Information. The entries are listed according to subject matter; topics range from general educational theory to more specific subject topics. (VM)

Informacion Bibliografica Educativa, 1972

1972-01-01

101

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)

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.

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

2013-05-01

102

CRECIMIENTO Y PRODUCCIN DE NUEVAS LEGUMINOSAS FORRAJERAS ANUALES EN LA ZONA MEDITERRNEA 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

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

2005-01-01

103

REVISIN SERRADELA AMARILLA (Ornithopus compressus) Y SERRADELA ROSADA (O. sativus): DOS NUEVAS ESPECIES DE LEGUMINOSAS FORRAJERAS ANUALES PARA LA ZONA MEDITERRNEA 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

104

Una Guia para Los Padres sobre La Educacion Especial: El Derecho de Su Hijo(a) a Adquirir una Educacion en el Estado de Nueva York (A Parent's Guide to Special Education: Your Child's Right to an Education in New York State).  

ERIC Educational Resources Information Center

This guide provides information to help parents of special needs children in New York become active partners in the planning and implementation of special education programs. The first part of the guide provides in-depth information related to the special education process in New York State public schools. A historical view of children's rights to

New York State Education Dept. Albany. Office for the Education of Children with Handicapping Conditions.

105

Notes on New Zealand chitons (Mollusca, Amphineura)  

Microsoft Academic Search

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

A. G. Beu

1967-01-01

106

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...

107

Kleptochemie und Kleptoplastie in Opisthobranchia (Mollusca: Gastropoda).  

E-print Network

??Zwei mgliche Schlsselmerkmale (Kleptoplastie und Kleptochemie) der Opisthobranchia werden untersucht. Im Fokus steht dabei die Nutzung von Naturprodukten als chemische Verteidigungsstrategie. Einige dieser Stoffe stammen (more)

Grzymbowski, Yvonne

2008-01-01

108

A Synoptical Classification of the Bivalvia (Mollusca)  

E-print Network

plesions and paraplesions, is provided in Appendix 3 (p. 27 herein). Symbols: = extinct; ! = paraphyletic; underlining = former members of Anomalodesmata; ? = taxonomic placement uncertain. Class Bivalvia Linnaeus, 1758 in 17581759 Grade... Order Solenida Dall, 1889 Order Hiatellida Carter, nov. DETAILED CLASSIFICATION Class Bivalvia Linnaeus, 1758 in 17581759 Grade Euprotobranchia! Nevesskaja, 2009 Order Fordillida! Pojeta, 1975 Superfamily Fordilloidea! Pojeta, 1975...

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

109

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

NASA Astrophysics Data System (ADS)

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 Michoacn-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.

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

2014-08-01

110

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

PubMed Central

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

Tan, Keng Hong; Nishida, Ritsuo

2012-01-01

111

CIS 1068: Practice Problems 12 Some more practice with objects and classes, especially Random, Math, Point, and String.  

E-print Network

CIS 1068: Practice Problems 12 Some more practice with objects and classes, especially Random, Math, Point, and String. 1. Fields a. What are 3 fields we have seen so far? (Hint: 1 in the Math class, 2 of these classes: Random, Math, Point, and String. For each method, indicate the data type of the value it returns

Yates, Alexander

112

Abstract--Non-verbal behavior is a mode of human interaction that is critical to communication, especially in situations where  

E-print Network

57 1 Abstract--Non-verbal behavior is a mode of human interaction that is critical to communication behavioral recurrence plots) to reveal the non-verbal behavior patterns of a tutor instructing a thirteen. Non-verbal behaviors, such as body language and movement, convey critical information, especially

Bartlett, Marian Stewart

113

Local Style Guide This guide is to help in your journalism sequence courses. It is especially used in  

E-print Network

Local Style Guide This guide is to help in your journalism sequence courses. It is especially used, etc., when using a shortened form, such as journalism school. (See also J-school.) But we capitalize the School of Journalism and Mass Communications. For degrees, it's bachelor's degree (avoid "baccalaureate

Almor, Amit

114

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

E-print Network

platforms: A case study with instrumented elephant seals in the Kerguelen region (Southern Ocean) Xiaogang profiles were measured by instrumented elephant seals in the Kerguelen region (Southern Ocean reference, especially for deep mixed waters, as in the Southern Ocean. Even in the shallow mixed waters

Claustre, Hervé

115

Universidade Federal do Rio de Janeiro Instituto de Biologia  

E-print Network

- M?DULO: MOLLUSCA Lúcia Siqueira Campos - M?DULO: ECHINODERMATA & GRUPOS LOFOFORADOS 06/fev Lophophorata Annelida 13/mar Annelida 14/mar Annelida 20/mar Avaliação de Annelida 21/mar Mollusca 27/mar Mollusca 28/mar Mollusca 03/abr Mollusca 04/abr Mollusca 10/abr Mollusca 11/abr Mollusca 17/abr PÁSCOA 18/abr

Paiva, Paulo Cesar de

116

Prediccin de los impactos del cambio climtico en la distribucin sobre las especies de Lepidoptera. El caso  

E-print Network

Lepidoptera. El caso del género Boloria Moore, 1900 en la Península Ibérica (Lepidoptera: Nymphalidae) H. Romo distribución de los Lepidoptera, lo que podría afectar más a especies propias de montaña en zonas templadas tendencias se confirman. PALABRAS CLAVE: Lepidoptera, Nymphalidae, Boloria, cambio climático, AUC, Max

García-Barros, Enrique

117

Fichas de las especies  

Microsoft Academic Search

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,

Santi Guallar; E. Santana; S. Contreras; H. Verdugo; A. Galls

2009-01-01

118

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

NASA Astrophysics Data System (ADS)

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

Blanco, A.; Maurrasse, F. J.; Hernndez-vila, J.; ngeles-Trigueros, S. A.; Garca-Cabrera, M. E.

2013-05-01

119

Original methods to move femoral head medially and caudally after rotational acetabular osteotomy: especially to use ceramic spacer.  

PubMed

The operative procedures chosen to treat arthrosis in patients with severe acetabular dysplasia vary among orthopaedic surgeons, particularly in younger patients. We operated on 450 hips with acetabular dysplasia by using the rotational acetabular osteotomy (RAO) method of Ninomiya and Tagawa by Ninomiya (Clin Orthop 247:127-137, 1989). In this report, we describe our technique of performing RAO with hydroxyapatite tricalcium phosphate-composite (HAP-TCP) blocks to achieve good acetabular coverage and the results of this procedure in 16 hips with severe dysplasia, including nine with advanced arthrosis. Adequate coverage of the osteotomized acetabulum was maintained and symptoms, especially pain, showed marked improvement at the latest follow up. PMID:16733753

Nozawa, Masahiko; Shitoto, Katsuo; Mastuda, Keiji; Maezawa, Katuhiko; Ogawa, Seiki; Yuasa, Takahito; Aritomi, Kentaro; Kurosawa, Hisashi

2006-08-01

120

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

PubMed

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

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

2015-01-01

121

Glitter-like iridescence within the bacteroidetes especially Cellulophaga spp.: optical properties and correlation with gliding motility.  

PubMed

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 "glitter" 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

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

2012-01-01

122

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

PubMed Central

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

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

2014-01-01

123

Extracellular Vesicles Derived from Gut Microbiota, Especially Akkermansia muciniphila, Protect the Progression of Dextran Sulfate Sodium-Induced Colitis  

PubMed Central

Gut microbiota play an important part in the pathogenesis of mucosal inflammation, such as inflammatory bowel disease (IBD). However, owing to the complexity of the gut microbiota, our understanding of the roles of commensal and pathogenic bacteria in the maintenance of immune homeostasis in the gut is evolving only slowly. Here, we evaluated the role of gut microbiota and their secreting extracellular vesicles (EV) in the development of mucosal inflammation in the gut. Experimental IBD model was established by oral application of dextran sulfate sodium (DSS) to C57BL/6 mice. The composition of gut microbiota and bacteria-derived EV in stools was evaluated by metagenome sequencing using bacterial common primer of 16S rDNA. Metagenomics in the IBD mouse model showed that the change in stool EV composition was more drastic, compared to the change of bacterial composition. Oral DSS application decreased the composition of EV from Akkermansia muciniphila and Bacteroides acidifaciens in stools, whereas increased EV from TM7 phylum, especially from species DQ777900_s and AJ400239_s. In vitro pretreatment of A. muciniphila-derived EV ameliorated the production of a pro-inflammatory cytokine IL-6 from colon epithelial cells induced by Escherichia coli EV. Additionally, oral application of A. muciniphila EV also protected DSS-induced IBD phenotypes, such as body weight loss, colon length, and inflammatory cell infiltration of colon wall. Our data provides insight into the role of gut microbiota-derived EV in regulation of intestinal immunity and homeostasis, and A. muciniphila-derived EV have protective effects in the development of DSS-induced colitis. PMID:24204633

Kang, Chil-sung; Ban, Mingi; Choi, Eun-Jeong; Moon, Hyung-Geun; Jeon, Jun-Sung; Kim, Dae-Kyum; Park, Soo-Kyung; Jeon, Seong Gyu; Roh, Tae-Young; Myung, Seung-Jae

2013-01-01

124

Extracellular vesicles derived from gut microbiota, especially Akkermansia muciniphila, protect the progression of dextran sulfate sodium-induced colitis.  

PubMed

Gut microbiota play an important part in the pathogenesis of mucosal inflammation, such as inflammatory bowel disease (IBD). However, owing to the complexity of the gut microbiota, our understanding of the roles of commensal and pathogenic bacteria in the maintenance of immune homeostasis in the gut is evolving only slowly. Here, we evaluated the role of gut microbiota and their secreting extracellular vesicles (EV) in the development of mucosal inflammation in the gut. Experimental IBD model was established by oral application of dextran sulfate sodium (DSS) to C57BL/6 mice. The composition of gut microbiota and bacteria-derived EV in stools was evaluated by metagenome sequencing using bacterial common primer of 16S rDNA. Metagenomics in the IBD mouse model showed that the change in stool EV composition was more drastic, compared to the change of bacterial composition. Oral DSS application decreased the composition of EV from Akkermansia muciniphila and Bacteroides acidifaciens in stools, whereas increased EV from TM7 phylum, especially from species DQ777900_s and AJ400239_s. In vitro pretreatment of A. muciniphila-derived EV ameliorated the production of a pro-inflammatory cytokine IL-6 from colon epithelial cells induced by Escherichia coli EV. Additionally, oral application of A. muciniphila EV also protected DSS-induced IBD phenotypes, such as body weight loss, colon length, and inflammatory cell infiltration of colon wall. Our data provides insight into the role of gut microbiota-derived EV in regulation of intestinal immunity and homeostasis, and A. muciniphila-derived EV have protective effects in the development of DSS-induced colitis. PMID:24204633

Kang, Chil-Sung; Ban, Mingi; Choi, Eun-Jeong; Moon, Hyung-Geun; Jeon, Jun-Sung; Kim, Dae-Kyum; Park, Soo-Kyung; Jeon, Seong Gyu; Roh, Tae-Young; Myung, Seung-Jae; Gho, Yong Song; Kim, Jae Gyu; Kim, Yoon-Keun

2013-01-01

125

Identification of Optimum Sequencing Depth Especially for De Novo Genome Assembly of Small Genomes Using Next Generation Sequencing Data  

PubMed Central

Next Generation Sequencing (NGS) is a disruptive technology that has found widespread acceptance in the life sciences research community. The high throughput and low cost of sequencing has encouraged researchers to undertake ambitious genomic projects, especially in de novo genome sequencing. Currently, NGS systems generate sequence data as short reads and de novo genome assembly using these short reads is computationally very intensive. Due to lower cost of sequencing and higher throughput, NGS systems now provide the ability to sequence genomes at high depth. However, currently no report is available highlighting the impact of high sequence depth on genome assembly using real data sets and multiple assembly algorithms. Recently, some studies have evaluated the impact of sequence coverage, error rate and average read length on genome assembly using multiple assembly algorithms, however, these evaluations were performed using simulated datasets. One limitation of using simulated datasets is that variables such as error rates, read length and coverage which are known to impact genome assembly are carefully controlled. Hence, this study was undertaken to identify the minimum depth of sequencing required for de novo assembly for different sized genomes using graph based assembly algorithms and real datasets. Illumina reads for E.coli (4.6 MB) S.kudriavzevii (11.18 MB) and C.elegans (100 MB) were assembled using SOAPdenovo, Velvet, ABySS, Meraculous and IDBA-UD. Our analysis shows that 50X is the optimum read depth for assembling these genomes using all assemblers except Meraculous which requires 100X read depth. Moreover, our analysis shows that de novo assembly from 50X read data requires only 640 GB RAM depending on the genome size and assembly algorithm used. We believe that this information can be extremely valuable for researchers in designing experiments and multiplexing which will enable optimum utilization of sequencing as well as analysis resources. PMID:23593174

Desai, Aarti; Marwah, Veer Singh; Yadav, Akshay; Jha, Vineet; Dhaygude, Kishor; Bangar, Ujwala; Kulkarni, Vivek; Jere, Abhay

2013-01-01

126

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

PubMed Central

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

Dutheil, Frdric; Trousselard, Marion; Perrier, Christophe; Lac, Grard; Chamoux, Alain; Duclos, Martine; Naughton, Geraldine; Mnatzaganian, George; Schmidt, Jeannot

2013-01-01

127

It's Tax Filing Season deadline April 17, 2012! This year, tax time is especially hectic because we have just transitioned from the Glacier system to the  

E-print Network

It's Tax Filing Season ­ deadline April 17, 2012! This year, tax time is especially hectic because we have just transitioned from the Glacier system to the Windstar International Tax Navigation system with both the software transition and 2011 tax filing: For Non-Residents Aliens for US Tax Purposes, we

Bordenstein, Seth

128

La funcin matemtica que describe el aumento en el nmero de especies al aumentar el rea se ha llamado species-area relationship (SAR, nada que ver  

E-print Network

llamado species-area relationship (SAR, nada que ver con el Sistema de Ahorro para el Retiro muestreo, las SARs se han empleado también para comparar la riqueza de especies de áreas continentales, insulares o marinas de diferentes tamaños. Como pueden ver, eso convierte a la SAR en un ejemplo de función

Nacional Autónoma de México, Universidad

129

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...

130

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

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

Minnesota, University of

131

The leading edge region of a first stage stator vane experiences high heat transfer rates especially near the endwall making it very important  

E-print Network

rates especially near the endwall making it very important to get a better understanding lends itself to high heat load demands on downstream turbine vanes. One of the regions having of the horse- shoe vortex wraps around the pressure side of the vane and the other around the suction side

Thole, Karen A.

132

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

Sessão Especial: Novas Tendências em Modelagem do Sistema Terrestre (New Trends on Land System múltipla escala, obteremos novas informações sobre os processos que comandam as mudanças do sistema

133

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 with different branches and different location. In this paper we propose a qualitative document management. The proposed framework provides the necessary options for creating an effective document management system

134

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

E-print Network

Sessão Especial: Big Data em Observação da Terra: infraestruturas e análises espaço-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

135

Biodiversity of the Fossil Record  

E-print Network

;Articulate Brachiopods #12;Mollusca #12;Mollusca: Class Bivalvia #12;Miocene marine bivalve, Maryland #12;Phylum Mollusca: Class Gastropoda #12;Nautilus, a cephalopod (Mollusca) #12;"Thing" examines a fossil nautiloid #12;Phylum Mollusca, Class Cephaplopoda, a goniatitic ammonoid #12;Phylum Mollusca, Class

Kammer, Thomas

136

Especially for High School Teachers  

NASA Astrophysics Data System (ADS)

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

Howell, J. Emory

1999-10-01

137

Especially for High School Teachers  

NASA Astrophysics Data System (ADS)

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

Howell, J. Emory

1999-08-01

138

Especially for High School Teachers  

NASA Astrophysics Data System (ADS)

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

Howell, J. Emory

2000-02-01

139

Especially for High School Teachers  

NASA Astrophysics Data System (ADS)

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.

Howell, J. Emory

2000-06-01

140

Especially for High School Teachers  

NASA Astrophysics Data System (ADS)

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.

Howell, J. Emory

2001-10-01

141

Especially for High School Teachers  

NASA Astrophysics Data System (ADS)

Supplementing a professional reading diet of chemical demonstrations, laboratory summaries, and classroom teaching strategies with accounts of new chemical discoveries and new understandings of chemical pedagogy is a healthy choice for the "living chemistry" teacher.

Literature Cited

  1. Calvin, M. J. Chem. Educ..1987, 64, 335.
  2. Wink, D. J. J. Chem. Educ. 1992, 69, 108.
  3. Wink, D. J. J. Chem. Educ. 1992, 69, 264.
  4. Schobert, H. H. J. Chem. Educ. 1989, 66, 242.
  5. Schobert, H. H. J. Chem. Educ. 1989, 66, 290.

Visit CLIC,an Online Resource for High School Teachers

Howell, J. Emory

2001-07-01

142

Especially for High School Teachers  

Microsoft Academic Search

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?

J. Emory Howell

1999-01-01

143

Especially for High School Teachers  

Microsoft Academic Search

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

J. Emory Howell

1999-01-01

144

Especially for Teens: Birth Control  

MedlinePLUS

... which controls the function of female reproductive organs. Human Immunodeficiency Virus (HIV): A virus that attacks certain cells of the bodys immune system and causes acquired immunodeficiency syndrome (AIDS). Pelvic Exam: ...

145

Especially for High School Teachers  

Microsoft Academic Search

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.

J. Emory Howell

2000-01-01

146

Especially for High School Teachers  

NASA Astrophysics Data System (ADS)

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

Howell, J. Emory

1999-02-01

147

Especially for High School Teachers  

NASA Astrophysics Data System (ADS)

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.

Howell, J. Emory

2000-10-01

148

Especially for High School Teachers  

NASA Astrophysics Data System (ADS)

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

Emory Howell, J.

1999-11-01

149

Loss of trematode parthenitae in Planorbella trivolvis (Mollusca: Gastropoda).  

PubMed

Infection by trematode parthenitae (larval, asexual trematodes) has severe consequences for molluscan hosts, resulting in cessation of reproduction and early mortality. Here we present evidence that the freshwater snail Planorbella trivolvis can lose infections by trematode parthenitae. Of 8 P. trivolvis infected by reniferin parthenitae, 6 died within 2 wk, whereas the remaining 2 snails lost their infections within 82 days after initial examination. This phenomenon might suggest that molluscs can resist established trematode infections (i.e., "self-cure") or at least out-survive some trematode parthenitae. PMID:23387507

Sears, B F; Rohr, J R

2013-08-01

150

Die Feinstruktur der stheten von Chiton olivaceus (Mollusca, Polyplacophora)  

Microsoft Academic Search

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

F. P. Fischer; M. Renner

1978-01-01

151

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

PubMed

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

Garca-Ros, Cedar I; Alvarez-Ruiz, Migdalia; Barraza, Jos E; Rivera, Ana M; Hasbn, Carlos R

2007-03-01

152

Amundsen Sea Mollusca from the BIOPEARL II expedition.  

PubMed

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

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

2013-01-01

153

Amundsen Sea Mollusca from the BIOPEARL II expedition  

PubMed Central

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

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

2013-01-01

154

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

PubMed

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

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

2002-02-25

155

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

Microsoft Academic Search

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

J. G Boal; D. K Golden

1999-01-01

156

Sublethal foot-predation on Donacidae (Mollusca: Bivalvia)  

NASA Astrophysics Data System (ADS)

The incidence of foot nipping was studied on the Donax spp. of the littoral of Mlaga (Southern Spain, 2875 specimens collected from February 1990 to January 1991) and of R island (French Atlantic coast, 262 specimens of Donax vittatus (Da Costa, 1778) collected in May 1996). In Mlaga, Donax trunculus L., 1758 was the species most regularly nipped (18% of individuals), with peaks in summer (25% in August and 48% in September) and winter (34% in December). In R island, 27% of the specimens showed a nipped foot. Logistic regression shows that in D. trunculus length is the variable that most influences the probability of foot nipping, followed by weight and chlorophyll a. However, the difference in length between damaged and undamaged individuals was not significant (U-Mann-Whitney test). The size class frequency and the values of Ivlev's index show that the small size classes were avoided, while for the other size classes predation remained balanced throughout the year. Therefore, the avoidance of the small size classes makes length the most influential variable. The logistic regression indicated a coefficient B=-0.03 for weight. This implies a slightly negative influence on the probability of foot nipping. However, without the data of September, there is a positive correlation ( r=0.76, p<0.01) between the monthly percentages of predation and the flesh dry weight of a standard individual (25 mm long). The peak in September could be due to the recruitment peak of bivalves, which may have attracted more predators to the area, and/or to the recruitment of predators such as crabs to the swash zone. Logistic regression and test of comparison of percentages indicate that there was not any influence of the sex of an animal on the probability of foot nipping. Only in February was a significantly higher percentage ( p<0.05) of females nipped (44.44%) than the total of females in the sample (20.20%). The biomass (as flesh dry weight) of D. trunculus lost by foot nipping amounts to more than 20% in most of the size classes. There was an increase from the small sizes to the largest ones, in which it reaches 37%, with a positive correlation ( r=0.84; p<0.005) between size class and loss of biomass. Possible predators responsible for the foot nipping are crabs. Crab species usually found together with the donacids were Portumnus latipes (Pennant, 1777) Liocarcinus vernalis (Risso, 1816) and Atelecyclus undecimdentatus (Herbst, 1783). In aquarium experiments, they demonstrated an ability to nip the foot of clams. Portumnus latipes was the most active foot nipper, but left alive all the damaged clams. Therefore, we conclude that crabs are the most likely foot-nipping predators in the field.

Salas, Carmen; Tirado, Cristina; Manjn-Cabeza, Maria Eugenia

2001-08-01

157

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

Microsoft Academic Search

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

Robert D. Ward

1990-01-01

158

Biodiversity and biogeography of Antarctic and sub-Antarctic mollusca  

NASA Astrophysics Data System (ADS)

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 AntarcticDronning Maud Land, East AntarcticEnderby Land, East AntarcticWilkes 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.

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

2006-04-01

159

Neuronal localization of dopamine and 5Hydroxytryptamine in some mollusca  

Microsoft Academic Search

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.

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

1966-01-01

160

Untersuchungen zur Landschneckenfauna (Mollusca: Gastropoda) des Nationalparks Thayatal.  

E-print Network

??Die Landschneckenfauna des Nationalparks Thayatal wurde auf ausgewhlten Flchen untersucht. Dabei konnten bei quantitativen Aufsammlungen 53 Arten, mit Handaufsammlungen und Barberfallenfngen 62 Arten an Waldstandorten (more)

Reischtz, Alexander

2008-01-01

161

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

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

162

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

NASA Astrophysics Data System (ADS)

Species of Vetigastropoda (Fissurellidae, Turbinidae, Trochidae) and one species of Neritimorpha (Neritidae) from the Navidad area, south of Valpara?so, and the Arauco Peninsula, south of Concepcin, 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.

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

2004-09-01

163

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

Microsoft Academic Search

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

MARY CRISP

164

Bioerzis s patolgis elvltozsok az egerien Mollusca faunjn.  

E-print Network

??A doktori rtekezsben vizsglom, bemutatom t egri s Eger krnyki, valamint egy dunntli egri kor feltrsbl gy?jttt puhatest? ?smaradvnyok mszvzain el?fordul bioerzis nyomokat, patolgis elvltozsokra (more)

Dvid, rpd

2004-01-01

165

Biodiversity and biogeography of Antarctic and subAntarctic mollusca  

Microsoft Academic Search

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.

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

2006-01-01

166

Evolutionary genetics of the family Placobranchidae (Mollusca: Gastropoda: Opisthobranchia: Sacoglossa).  

E-print Network

??Members of the family Placobranchidae have been the focus of numerous studies because of their interesting physiological adaptations (kleptochemistry and kleptoplasty) and ecological associations with (more)

Bass, Anna Lee

2006-01-01

167

A review of the family Clenchiellidae (Mollusca: Caenogastropoda: Truncatelloidea).  

PubMed

The truncatelloidean family Clenchiellidae, previously treated as a tribe or subfamily of Hydrobiidae, is diagnosed as a distinct family including Clenchiella and three new genera, Coliracemata, Colenuda and Coleglabra. The family is characterised by the discoidal shell with spiral keels or cords, and a wide umbilicus. All species are found in mangrove swamps or adjacent habitats in tropical estuaries, with the exception of one riverine and one lacustrine species. Clenchiella includes the type species, C. victoriae Abbott, from the Philippines, the widespread C. minutissima (Wattebled) (= C. papuensis Benthem Jutting) from Vietnam, Singapore, Thailand, Papua New Guinea and tropical Australia, and three new species, C. bicingulata n. sp. from Singapore and Thailand, C. varicosa n. sp. from Hong Kong and Taiwan, and C. iriomotensis n. sp. from Okinawa, Japan. Coliracemata n. gen. includes C. mortoni n. sp. (type of the genus) from Hong Kong, C. katurana n. sp. from Okinawa, C. clarkae n. sp. from northeastern Australia, and tentatively C. microscopica (Nevill) and C. innocens (Preston) from India. Colenuda n. gen. consists of a single species, C. kessneri n. sp., from Northern Territory, Australia. Coleglabra n. gen. includes C. nordaustralis n. sp. (type of the genus) from Northern Territory and C. sentaniensis (Benthem Jutting) from a freshwater lake in Irian Jaya. Anatomical characters are described for nine of the twelve species. The Clenchiellidae is shown to be more closely related to Calopiidae, Tornidae, and Iravadiidae, than to Hydrobiidae. PMID:25544076

Ponder, Winston F; Fukuda, Hiroshi; Hallan, Anders

2014-01-01

168

Complete male mitochondrial genome of Anodonta anatina (Mollusca: Unionidae).  

PubMed

Abstract Anodonta anatina is a freshwater mussel of the family Unionidae. These mussels have a unique mitochondria inheritance system named doubly uniparental inheritance (DUI). Under DUI males have two, potentially very divergent mitochondrial genomes: F-type inherited from mother and M-type inherited from father. F-type is present in soma whereas M-type is present in gonadal tissues and sperm. Here we report two M-type sequences of complete mitochondrial genomes from Anodonta anatina. They are 16,906?bp long and their sequences are similar (0.1% divergence). The genome organization is identical to the other Unionidean M-type genomes published to date. There are 38 genes, including the recently described M-type specific M ORF. The presence of tRNA-like repeat in one of the noncoding regions, suggests that the control region is located in this area. Nucleotide composition is quite extreme, with AT content (66.2%) higher than in any other of the six published Unionidean M genomes. PMID:25317641

Soroka, Marianna; Burzy?ski, Artur

2014-10-15

169

RECENT MOLLUSCA OF ARKANSAS WITH ANNOTATIONS TO SYSTEMATICS AND ZOOGEOGRAPHY  

Microsoft Academic Search

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.

MARK E. GORDON

170

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

Microsoft Academic Search

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

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

2005-01-01

171

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

USGS Publications Warehouse

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.

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

2010-01-01

172

Nodules in the achiasmatic meiosis of Bithynia (mollusca, prosobranchia)  

Microsoft Academic Search

In spermatocytes of Bithynia leachi and B. tentaculata, synaptonemal complexes with nodules in an achiasmatic meiosis were demonstrated for the first time by means of the spreading technique. The number and position of the nodules are different in each species and are independent of the length of the chromosomes. Although no crossing over occurs in Bithynia chiasma-like terminal connections of

Birgit Debus; Postfach I

1978-01-01

173

"Nodules" in the achiasmatic meiosis of Bithynia (Mollusca, Prosobranchia).  

PubMed

In spermatocytes of Bithynia leachi and B. tentaculata, synaptonemal complexes with nodules in an achiasmatic meiosis were demonstrated for the first time by means of the spreading technique. The number and position of the nodules are different in each species and are independent of the length of the chromosomes. Although no crossing over occurs in Bithynia chiasma-like terminal connections of the chromosomes are preserved in diakinesis by the presence of the nodules. --Enzymatic treatments revealed information regarding their composition of alkaline proteins, RNA and DNA. In all proteolytic digestions the nodules more of less retain their position in the central region, while they disappear immediately if SCs are exposed to DNase. On the basis of the results a model of the composition and the function of nodules can be developed considering the concept of a lampbrush-organization of the chromosomes in early meiotic prophase. PMID:738164

Debus, B

1978-10-20

174

Plicaustraconus a new genus in the family Conidae (Mollusca, Gastropoda)  

Microsoft Academic Search

After more than 200 years the subdivision of the genus Conus in still related (sub)genera is still problematic. A peculiar plicae or fold on the anterior part of the columella of the genus Conus is a character shared by group of western Australian cones.

R. G. Moolenbeek

2008-01-01

175

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)

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.

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

2003-01-01

176

[Trail use of new phytoindicators in connection with passive sampling of traffic air pollution monitoring [especially for (synergistic) effects NO2 and SO2  

PubMed

Introduced research was connected with exposure of liverword Marchantia polymorpha in selected places in the area of Krakow. Places differing in regard to average concentration of air pollution [especially for (synergistic) effects NO2 and SO2]. Purpose of research was to check correlation between exposure to different concentrations of NO2 and SO2 (in regard to their synergistic effects) and possible differences in dynamics of growth of M. polymorpha. Samples of M. polymorpha located in soil, which was standardly analysed (in regard to contents of trace elements) before and after exposure. Research was simultaneously performed with similar exposure culture in vitro of Petunia hybrida. To growing tissues of petunia was used standard Murashige & Skoog medium and was protected against infections (with using filter of fibre). Described biomonitoring was completed by measurements of concentration of NO2 and SO2 by passive method with use of samplers of Amaya and Krochmal, in the same places, where was located exposure of plants. Observed was inhibition of growth in places, where was high concentration both gases. PMID:15682941

Bach, Anna; Warcho?, Marzena; Gowin, Katarzyna

2004-01-01

177

AM fungi root colonization increases the production of essential isoprenoids vs. nonessential isoprenoids especially under drought stress conditions or after jasmonic acid application.  

PubMed

Previous studies have shown that root colonization by arbuscular mycorrhiza (AM) fungi enhances plant resistance to abiotic and biotic stressors and finally plant growth. However, little is known about the effect of AM on isoprenoid foliar and root content. In this study we tested whether the AM symbiosis affects carbon resource allocation to different classes of isoprenoids such as the volatile nonessential isoprenoids (monoterpenes and sesquiterpenes) and the non-volatile essential isoprenoids (abscisic acid, chlorophylls and carotenoids). By subjecting the plants to stressors such as drought and to exogenous application of JA, we wanted to test their interaction with AM symbiosis in conditions where isoprenoids usually play a role in resistance to stress and in plant defence. Root colonization by AM fungi favoured the leaf production of essential isoprenoids rather than nonessential ones, especially under drought stress conditions or after JA application. The increased carbon demand brought on by AM fungi might thus influence not only the amount of carbon allocated to isoprenoids, but also the carbon partitioning between the different classes of isoprenoids, thus explaining the not previously shown decrease of root volatile isoprenoids in AM plants. We propose that since AM fungi are a nutrient source for the plant, other carbon sinks normally necessary to increase nutrient uptake can be avoided and therefore the plant can devote more resources to synthesize essential isoprenoids for plant growth. PMID:22296838

Asensio, Dolores; Rapparini, Francesca; Peuelas, Josep

2012-05-01

178

Aa (Euterpe oleracea Mart.): a tropical fruit with high levels of essential minerals-especially manganese-and its contribution as a source of natural mineral supplementation.  

PubMed

Aa is a fruit from the Brazilian Amazon region, with an exotic flavor, possessing high antioxidant and anti-inflammatory properties. Based on these properties, the fruit is classified as one of the new "super fruits." The mean daily consumption of aai pulp may reach 300 ml in several Brazilian regions. Further, this fruit is also gaining popularity in Europe and North America. In this context, the aim of this study was to assess the levels of some essential minerals in freeze-dried aa pulp obtained in different Brazilian locations. It was found that aa pulp is rich in essential minerals (Ca, Fe, Mg, Zn), but the levels of copper (Cu) and especially manganese (Mn) are surprisingly markedly higher than the traditional sources of these elements in the human diet. A daily consumption of 300 ml aa pulp leads to a Mn daily intake exceeding at least sixfold (14.6 mg on average) the reference daily intake for an adult. Consequently, Mn intake may surpass the permitted daily maximum intake of 11 mg, which leads to a special concern, particularly for children, vegetarians, and individuals with anemia, since iron (Fe) absorption is impaired by Mn. Our findings demonstrate that this fruit is a potential source of several nutrients and a good dietary supplement to resolve malnutrition problems. However, due to the expressive levels of Mn, further studies are necessary to evaluate potential adverse effects associated with aa consumption. PMID:24555649

da Silva Santos, Vivian; de Almeida Teixeira, Gustavo Henrique; Barbosa, Fernando

2014-01-01

179

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

SciTech Connect

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.

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

1984-05-01

180

Apo E Gene Polymorphism Affects Development of Type 2 Diabetic Nephropathy in Asian Populations, Especially in East Asians: An Updated Meta-Analysis  

PubMed Central

Background Many studies have determined the correlation between the Apolipoprotein E (APO E) gene polymorphisms and diabetic nephropathy, but their results are inconclusive. Material/Methods With the aim to confirm this correlation, we performed a meta-analysis of 16 studies. The dichotomous data are presented as the odds ratio (OR) with a 95% confidence interval (CI). Results The results of our study indicate that APO ?2 allele among the pooled Asian populations were more likely to show high risk of DN development (2 allele vs. ?3 allele: pooled OR =1.629, 95% CI=1.0102.628, P=0.045). For further analysis, the APO ?2 allele was associated with progress of DN in the group with duration >10 years, but not in the group with duration <10 years (?2 allele vs. ?3 allele: pooled OR=1.920, 95% CI=1.3382.754, P<0.001). The APO ?2 polymorphism increased the susceptibility to DN in Asian population compared with healthy people (?2 allele vs. ?3 allele: pooled OR=1.629, 95% CI=1.0102.628, P=0.045). Conclusions Development of DN is associated with APO E polymorphisms in Asian populations, especially in East Asians. PMID:25196797

Lin, Yi-jin; Pan, Jin-lin; Jiang, Min-juan; Tan, Jun-hua; Zhong, Wei; Gong, Tie-kai; Jin, Xiao-chan; Cai, Shi-hong; Wu, Yao-jun

2014-01-01

181

Blood lines conduct leakage current during haemodialysis: a potential safety risk during first failure, especially for patients with central dialysis catheter as access.  

PubMed

Haemodialysis (HD) machines are IEC-classified as I type B. When central dialysis catheters (CDCs) are used for access, there will be close electrical contact with the heart. To investigate the risk for HD patients, the leakage of current through the tubing set was measured during in vitro dialysis performed according to the IEC 60601-1 standard for class I cardiac floating (CF) devices. A series of eight measurements were made with Gambro GFS + 12 dialysers, first with saline and then with blood in the blood lines. The leakage current exceeded the CF limit (50 microA) at the top of the CDC using the test 'mains on applied part' for saline (median 1008 microA, range 720-1241 microA), for blood (median 610 microA, range 449-772 microA) and also for a 'single fault condition' using saline (median 68 microA, range 35-118 microA) or blood (47 microA, range 4-128 microA). In the single fault condition, the highest leakage current at the CDC (128 microA) almost exceeded the earth leakage current in normal conditions. A safety risk can appear if a single fault arises in the dialysis machine or another device connected to the same patient, or during 'mains contact to the patient'. Then the current flow may be high enough to induce arrhythmias in the patient, especially when a CDC is used. These data and the use of CDCs as access for dialysis indicate that HD machines should be classified as cardiac floating rather than body (B) devices. PMID:16594299

Jonsson, P; Eliasson, G; Stegmayr, B G

2005-11-01

182

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

PubMed

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 C for 3 h or, in the case of poly(methyl methacrylate), at 100 C 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

lamborov, Irena; Zajcov, Veronika; Karpkov, Jana; Exnar, Petr; Stibor, Ivan

2013-01-01

183

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

PubMed

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

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

184

ID2 predicts poor prognosis in breast cancer, especially in triple-negative breast cancer, and inhibits E-cadherin expression  

PubMed Central

Background Inhibitors of DNA-binding (ID) proteins are known as important modulators in the regulation of cell proliferation and differentiation. This study sought to investigate the prognostic value of ID proteins in breast cancer. Methods The prognostic role of ID proteins in human breast cancer was investigated in 250 breast cancers, via tissue microarrays. The messenger (m)RNA and protein levels of E-cadherin were examined by quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and Western blotting, in cells overexpressing IDs. Dual-luciferase report assay was used to investigate the potential mechanism, and a migration assay was performed to investigate the influence of IDs on cell migratory activity. Results The survival analysis with KaplanMeier and Cox regression showed that ID2 expression level, which correlated with estrogen receptor status and E-cadherin abundance, served as an independent prognostic factor for disease-free survival (DFS) (P=0.013). The prognostic value of ID2 for DFS was most significant in triple-negative breast cancer patients (P=0.009). We also found that ID2 was negatively correlated with E-cadherin expression by correlation analysis (P=0.020, Pearsons R=?0.155). Subsequently, we explored the biological rationale and uncovered that the enforced expression of ID proteins could suppress E-cadherin expression significantly, thus increasing the migration ability of mammary epithelial cells. Then using a combination of ID2 and E-cadherin expression, the patients were classified into four subgroups with different DFS (P=0.023). Conclusion The overexpression of ID2 can be used as a prognostic marker in breast cancer patients, especially in triple-negative breast cancer patients. ID proteins were still, unexpectedly, revealed to inhibit E-cadherin abundance. PMID:24971018

Li, Kai; Yao, Ling; Chen, Li; Cao, Zhi-Gang; Yu, San-Jian; Kuang, Xia-Ying; Hu, Xin; Shao, Zhi-Ming

2014-01-01

185

Introduction: Integrating pH sensors in microfluidic systems can provide in-situ measurement functionality for micro-scale fluidic processing and analyzing applications, especially for medicine synthesis, bioanalysis of drugs  

E-print Network

functionality for micro-scale fluidic processing and analyzing applications, especially for medicine synthesis metal electrode. The sol-gel solution was prepared according to our recipe previously published in [1

Chiao, Jung-Chih

186

Biodiversity of the Fossil Record  

E-print Network

Inarticulate Brachiopods #12;Articulate Brachiopods #12;Mollusca #12;Mollusca: Class Bivalvia #12;Miocene marine bivalve, Maryland #12;Phylum Mollusca: Class Gastropoda #12;Nautilus, a cephalopod (Mollusca) #12;"Thing" examines a fossil nautiloid #12;Phylum Mollusca, Class Cephaplopoda, a goniatitic ammonoid #12

Kammer, Thomas

187

Biology 221 Fall 2011 Midterm 2 Test Number KEY Part 1 (short answer) worth 2-4 points each (20 % of grade)  

E-print Network

? (2 pts). Mollusca Which of these represents the earlier life history stage during larval development fits. You may use a taxon more than once or not at all: a) Mollusca Oyster Arthropoda b) Arthropoda Cniderian f) Agnathan Lamprey Mollusca g) Mollusca Chiton Echinoderm h) Mollusca Squid Lophophorate i

Clifton, Ken

188

El espanol: La lengua de Puerto Rico. Aprecio y defensa de nuestra lengua materna en la ciudad de Nueva York (Spanish: Language of Puerto Rico. Appreciation and Defense of our Mother Tongue in New York City).  

ERIC Educational Resources Information Center

The author presents her appreciation and defense of Spanish as it is spoken in New York City, especially among Puerto Ricans. She believes that the institution of bilingual education in the city's schools is an important first step in elevating Spanish to the position it deserves as a means of instruction and communication. The instructional

Ramirez de Arellano, Diana

189

LA SALUD MENTAL DEL BEB. NUEVAS EVIDENCIAS  

Microsoft Academic Search

SUMMARY This article describes infant mental health from two perspectives: why it is relevant and how to implement interventions, including preventive ones. Topics covered are based on evidence available in scientific literature. The first section addresses areas that justify the importance assigned to infants and their emotional well-being. One of them deals with new information about brain development. Recent available

J. Martn Maldonado-Durn; Juan Manuel Sauceda Garcia; Teresa Lartigue; Velissarios Karacostas

2002-01-01

190

La gripe aviar Una nueva amenaza pandmica?  

E-print Network

Investigación y Tecnología Agraria y Alimentaria Ramón Soriguer, Estación Biológica de Doñana (CSIC) Madrid (coord.), Pilar Pérez-Breña, Agustín Portela, Gustavo del Real y Ramón Soriguer, 2007 Reservados todos

Figuerola, Jordi

191

INVERTEBRATE ZOOLOGY (Biol-20300) LECTURE SCHEDULE -Fall 2007  

E-print Network

Pogonophora, Echiura) Chapter 13 Tues., Oct. 30 Sipuncula, Mollusca Chapters 13, 12 Thurs., Nov. 1 Mollusca Chapter 12 Tues., Nov. 6 Mollusca, introduction to Arthropoda Chapters 12, 14 Thurs., Nov. 8 Arthropoda

Smith, Bruce

192

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

E-print Network

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

Mollov, Ivelin Aldinov

193

Date Sunrise/ Tide Time KB  

E-print Network

. 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

Carrington, Emily

194

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

E-print Network

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

Nishiguchi, Michele

195

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

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

Hille, Sander

196

The Medical College of Wisconsin-Central Wisconsin campus is expected to open in 2016 and will bring a new era of medical education to students who find it especially appealing to live, learn and eventually  

E-print Network

The Medical College of Wisconsin-Central Wisconsin campus is expected to open in 2016 and will bring a new era of medical education to students who find it especially appealing to live, learn and high-caliber faculty, balanced with access to a great quality of life where year-round outdoor sports

197

UNIVERSIDADE FEDERAL DE SANTA CATARINA CENTRO DE CINCIAS BIOLGICAS  

E-print Network

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

Floeter, Sergio Ricardo

198

J. Zool., Lond. (1996) 238,287-299 Loss of male outcrossing ability in simultaneous hermaphrodites  

E-print Network

-compatiblepulmonates (Mollusca: Gastropoda), presents an opportunity to examine factors maintaining outcrossing within an animal the Pulmonata (Mollusca: Gastropoda), and presents an opportunity Present address: Department of Biology, Emory

Read, Andrew

199

Z .Comparative Biochemistry and Physiology Part B 131 2002 55 61 Unique Ca2q  

E-print Network

in the nervous ganglia of z /Phyllocaulis soleiformis Mollusca Rosane Souza Da Silvaa , Giana de Paula Cognatoa; Invertebrates; Mollusca; Mollusks; Nervous ganglia; Phyllocaulis soleiformis 1. Introduction Z .Phyllocaulis

Eizirik, Eduardo

200

Lauterbornia 63: 3-13, D-86424 Dinkelscherben, 2008-09-10 Die Wassermollusken des Naturschutzgebietes "Drewitzer  

E-print Network

Abbildungen und 1 Tabelle Schlagwörter: Anisus, Myxas, Pisidium, Gastropoda, Bivalvia, Mollusca, Mecklenburg, Pisidium, Gastropoda, Bivalvia, Mollusca, Mecklenburg-Vorpommern, Germany, lake, mesotrophic, habitat

Zettler, Michael

201

Research Article Open AccessResearch Article Open Access Cytology & Histology  

E-print Network

antipodarum; Phylum: Mollusca; Class: Gas- tropoda; Family: Hydrobiidae; Genus: Potamopyrgus; photo: CEMAGREF Lyon, France. Figure 2: Adult Valvata piscinalis; Phylum: Mollusca; Class: Gastropoda; Family

Paris-Sud XI, Université de

202

What is Biomphalaria glabrata? Biomphalaria glabrata is a mollusc and thus represents the lophotrochozoan clade of animal  

E-print Network

BRYOZOA BRACHIOPODA PHORONIDA ANNELIDA MOLLUSCA SIPUNCULIDA PLATYHELMINTHS PLACOZOA CNIDARIA PORIFERA DEUTEROSTOMES ECDYSOZOANS LOPHO- TROCHOZOANS #12;Phylum Mollusca · >50 thousand living species · Includes

Loker, Eric "Sam"

203

Especially for Teens: Having a Baby  

MedlinePLUS

... taking medications during pregnancy? Can using alcohol, tobacco, marijuana, or other illegal drugs cause harm during pregnancy? ... remedies, vitamins, or minerals. Can using alcohol, tobacco, marijuana, or other illegal drugs cause harm during pregnancy? ...

204

[Biotechnology, especially genetic modification, and legislation].  

PubMed

Biotechnology and genetic modification (GM) related legislation is not yet fully developed in the European Union (EU). New legislation has been recently issued ('Introduction of GMO's in the environment') and recently proposals from the European Commission ('GMO's in food and feed' and 'Traceability and labelling of GMO's') entered the decision-making process in the end of 2001. The proposals for the establishment of the European Food Authority play a role in this respect. GMO legislation is complex not in the least because of the demands for the dossiers, to be submitted with an application, while these procedures for admission must become more transparent. In this paper the relevant legislation will be discussed with the exception of that related to human health. Because of dissatisfaction with the present legislation, the European Commission in the past years granted no new approvals for introductions on the market of GMO's and for GM novel foods. New legislation should suspend the present de-facto moratorium. The tasks and position of the Inspectorate for the Health Protection and Veterinary Public Health is discussed. A provision has been made in the legislation with respect to adventitious or technically unavoidable contamination of raw materials with GMO's up to a maximum of 1%, of which the enforcement is not yet watertight. The analytical methods are being still developed. PMID:12056264

de Sitter, H; Peters, P W J

2002-05-15

205

[Treatment of especially severe sex offenses].  

PubMed

"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

Pffflin, F; Haake, E

1983-05-01

206

Especially for Teens: Having a Baby  

MedlinePLUS

... of mercury, which can be harmful during pregnancy. Caffeine C affeine is found in coffee, tea, chocolate, energy drinks, and soft drinks. It is a good idea to limit your daily intake of caffeine to less than 200 milligrams, which ...

207

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.

208

Art in medical education: Especially plastic surgery  

Microsoft Academic Search

The importance of art studies in the training of plastic surgeons has not been well recognized. Presently, very few medical schools offer courses on art or include it in the humanities. Because the study of art is a great experience that helps to develop the trained eye, the inclusion of art in medical education is recommended. For plastic and aesthetic

Alma Dea Morani

1992-01-01

209

Russian vaccines against especially dangerous bacterial pathogens  

PubMed Central

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.

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

2014-01-01

210

The Book Scene...Especially for Teens.  

ERIC Educational Resources Information Center

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

Peskorz, Adela, Comp.; And Others

211

Indicadores internacionales de Soberana Alimentaria. Nuevas herramientas para una nueva agricultura  

Microsoft Academic Search

La crisis alimentaria del ao 2008 situ en la agenda poltica, una vez ms, uno de los retos globales ms importantes que la humanidad debe afrontar: satisfacer el derecho a la alimentacin de una manera sostenible. La Soberana Alimentaria es un concepto, propuesto y desarrollado por numerosas organizaciones campesinas, que puede contribuir al objetivo planteado. No obstante para aumentar el

Miquel Ortega-Cerd; Marta G. Rivera-Ferre

2010-01-01

212

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

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

U. D. Deshpande; R. Nagabhushanam

1983-01-01

213

Zoology 220 Lecture Syllabus -Spring 2014 Date Topic Reading (Chapter: pages)  

E-print Network

), Ctenophora 7: 149-153 5 Feb. Trochozoa: Mollusca (Polyplacophora, etc.) 10: 186-194 7 Feb. EXAM 1 Chapters 1-7 10 Feb. Trochozoa: Mollusca (Gastropoda) 10: 194-200 12 Feb. Trochozoa: Mollusca (Bivalvia) 10: 200-204 14 Feb. Trochozoa: Mollusca (Cephalopoda) 10: 204-212 17 Feb. Trochozoa: Annelida ("Polychaetes") 11

Nickrent, Daniel L.

214

DEPARTMENTAL SEMINAR INTEGRATIVE ZOOLOGY Programme Summer Term 2014  

E-print Network

(Mollusca: Bivalvia). Apr 29 : Denise Ivenz: Hoverfly Communities in the NP Gesäuse. 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

Pass, Günther

215

OIMB GK12 Lesson Kelp Forest Invertebrates  

E-print Network

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

217

Allozymic Differentiation Among Geographically Distant Populations of Patella vulgata (Mollusca, Patellogastropoda)  

Microsoft Academic Search

Patella vulgata is a boreal cold temperate species and is the dominant limpet in northern Europe. Few works have focussed on the population\\u000a genetics of this species. Therefore, the aim of this work was to assess the degree of genetic and morphological differentiation\\u000a of P. vulgata on a macroscale by using 20 allozyme loci and 6 morphological variables. Samples were

L. I. Weber; L. I. Hawkins

2006-01-01

218

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

E-print Network

not affect chloride levels in the porcelain crab, Petrolisthes armatus. Although chloride ions are not themselves normally regulated in estuarine invertebrates, they may co-migrate with actively regulated sodium ions to maintain electrical neutrality...

Dillon, T. M

1976-01-01

219

Caloric variability of Corbicula fluminea (Mollusca, Bivalvia) in Rosana Reservoir, Brazil  

Microsoft Academic Search

The purpose of the present study was to investigate temporal and longitudinal variation of caloric den sity of Corbicula fluminea in Rosana Reservoir. Significant differences conce rning the caloric density of C. fluminea were observed throughout the year at the three reservoir sites. The caloric density variation during the ye ar was probably related to reproductive activity, which demanded hi

Yara Moretto Bagatini; Evanilde Benedito-Cecilio; Janet Higuti

2007-01-01

220

Phylogenetic relationships among major species of japanese coleoid cephalopods (Mollusca: Cephalopoda) using three mitochondrial DNA sequences.  

PubMed

Phylogenetic relationships among 36 species of major coleoid cephalopods from Japanese waters were studied using partial sequences of three mitochondrial genes, 16S rDNA, 12S rDNA, and cytochrome c oxidase subunit I gene. Octopoda and Decapoda were monophylic groups. Within Sepioidea, Sepiadariidae and Sepiolidae were not closely related to Sepiidae, but rather related to Teuthoidea. Sepiidae with a distinct calcareous shell formed a single cluster. Myopsida was closely related to Oegopsida. Within Octopoda, Opisthoteuthis depressa and Argonauta argo diverged earlier than Octopodiidae. The common octopuses in Japanese waters were separated into three clusters. The first cluster occupied a basal position, and includes large-sized octopuses, such as Enteroctopus dofleini and Octopus (Paroctopus) conispadiceus from the continental shelf and upper slope. The second cluster consisted of long-armed octopuses, such as O. ornatus, O. minor, and O. sasakii. The third cluster contained small- to medium-sized octopus, such as Amphioctopus fangsiao, A. areolatus, O. cyaneus, and O. vulgaris, in which several species possess ocelli on the web. The second cluster formed the sister group to the third cluster. PMID:15738635

Takumiya, Mikio; Kobayashi, Mari; Tsuneki, Kazuhiko; Furuya, Hidetaka

2005-02-01

221

Ultrastructural characteristics of typical and atypical spermatogenesis in the queen conch Strombus gigas (Mollusca, Gastropoda)  

Microsoft Academic Search

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

NATHALIE CASSE; MARCEL LE PENNEC; ANGLE HERRY; GRARD SINQUIN; GERMAINE DORANGE

1994-01-01

222

Dynamics and ecology of an Indo-Pacific conch, Conomurex persicus (Mollusca: Gastropoda) in southeastern Turkey.  

PubMed

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

Mutlu, Erhan; Ergev, Mehmet Betil

2006-03-01

223

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

Microsoft Academic Search

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

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

1983-01-01

224

Chiton integument: Ultrastructure of the sensory hairs of Mopalia muscosa (Mollusca: Polyplacophora)  

Microsoft Academic Search

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

Esther M. Leise; Richard A. Cloney

1982-01-01

225

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

Microsoft Academic Search

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.

Steinar kland

1981-01-01

226

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

PubMed

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

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

2002-02-01

227

The role of the follicle cells during oogenesis in the chiton Sypharochiton septentriones (Ashby) (Polyplacaphora, Mollusca)  

Microsoft Academic Search

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

Lynne Selwood

1970-01-01

228

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

PubMed

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

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

2013-01-01

229

18S ribosomal DNA sequences provide insight into the phylogeny of patellogastropod limpets (Mollusca: Gastropoda).  

PubMed

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

Yoon, Sook Hee; Kim, Won

2007-02-28

230

Die stheten mit intrapigmentrem Schalenauge von Chiton marmoratus L. (Mollusca, Placophora)  

Microsoft Academic Search

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

Winfried Haas; Klaus Kriesten

1978-01-01

231

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

Microsoft Academic Search

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

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

1983-01-01

232

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

PubMed

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

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

2012-09-01

233

Fine structure of the mineralized teeth of the chiton Acanthopleura echinata (Mollusca: Polyplacophora).  

PubMed

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

Wealthall, Rosamund J; Brooker, Lesley R; Macey, David J; Griffin, Brendan J

2005-08-01

234

[Polyplacophoran communities (Mollusca: Polyplacophora) at Bahia de La Paz, Baja California Sur, Mxico].  

PubMed

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

Garca Ros, Cedar I; Alvarez Ruiz, Migdalia

2007-03-01

235

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

Microsoft Academic Search

Mature sperm of the three species, Onithochiton quercinus, Chiton pelliserpentis and Plaxiphora paeteliana are eupyrene and basically of the primitive 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

E. R. Sakker

1984-01-01

236

The continuing debate on deep molluscan phylogeny: evidence for Serialia (Mollusca, Monoplacophora + Polyplacophora).  

PubMed

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

Stger, I; Sigwart, J D; Kano, Y; Knebelsberger, T; Marshall, B A; Schwabe, E; Schrdl, M

2013-01-01

237

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

PubMed

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

Avila, Srgio P; Sigwart, Julia

2013-01-01

238

A new species of hydrobiid snails (Mollusca, Gastropoda, Hydrobiidae) from central Greece  

PubMed Central

Abstract Anew minute valvatiform species belonging to the genus Daphniola Radoman, 1973, Daphniola eptalophos sp. n., from mountain Parnassos, Greece is described. The new species has a transparent valvatiform-planispiral shell, wide and open umbilicus, grey-black pigmented soft body and head and a black penis with a small colorless outgrowth on the left side near its base. A comparative table of shell dimensions and a key to the species known for this endemic genus for Greece are provided. PMID:22144853

Radea, Canella

2011-01-01

239

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

Microsoft Academic Search

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

N Koueta; E Boucaud-Camou

2001-01-01

240

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

Microsoft Academic Search

The AtlanticMediterranean 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

Marcos Prez-Losada; ngel Guerra; Andrs Sanjuan

1999-01-01

241

Melanoides tuberculata (Mollusca: Thiaridae) harboring renicolid cercariae (Trematoda: Renicolidae) in Brazil.  

PubMed

Melanoides tuberculata , naturally infected by gymnocephalous cercariae, were found in aquatic collections from Belo Horizonte, Minas Gerais, Brazil. After morphological characterization, larvae were used for experimental infection of Poecilia reticulata. Metacercariae were obtained from the liver of these fish, which were also found to be naturally infected in the same locality. The morphology and biology of the developmental stages of trematodes we obtained were characteristic of Renicola sp. This is the first record of renicolid cercariae and metacercariae in Brazil. PMID:22288437

Pinto, H A; Melo, A L

2012-08-01

242

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

PubMed

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

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

2013-10-01

243

The shallow-water New Caledonia Drilliidae of genus Clavus Montfort, 1810 (Mollusca: Gastropoda: Conoidea).  

PubMed

Species of the genus Clavus of the conoidean family Drilliidae that occur in the littoral and shallow waters of New Caledonia are here revised. This study is based primarily on recent expedition material from the Institut de Recherche pour le Dveloppement (New Caledonia) and Musum National d'Histoire Naturelle (France). A total of 22 species is recorded, of which eight are described as new. New species: Clavus boucheti, Clavus delphineae, Clavus virginieae, Clavus picoides, Clavus squamiferus, Clavus devexistriatus, Clavus hylikos, Clavus maestratii; New synonyms: Tylotiella Habe, 1958 = Clavus; Clavus leforestieri Hervier, 1896 = Pleurotoma obliquicostata Reeve, 1845; Pleurotoma mariei Crosse, 1869 = Pleurotoma lamberti Montrouzier, 1860; Clavus mighelsi Kay, 1979, new name for Pleurotoma acuminata Mighels, 1845, non J. Sowerby, 1816, was misidentified by Kay 1979; the lectotype of P. acuminata Mighels, 1845, is mangeliine. Clavus mighelsi sensu Kay 1979, is a synonym of Pleurotoma humilis E. A. Smith, 1879. It is suggested that Pleurotoma pulchella Reeve, 1845, sometimes treated as an Indo-Pacific species, may be a senior synonym of Fenimorea halidorema Schwengel, 1940, from the tropical western Atlantic. Nomen dubium: Pleurotoma mediocris Deshayes, 1863. PMID:24943803

Kilburn, Richard N; Fedosov, Alexander; Kantor, Yuri

2014-01-01

244

Bathymetric records of marine shelled mollusca from the northeastern shelf of Yucatan, Mexico  

E-print Network

6i 61 6k 7b, 7c 6h Retusa obesiuscula Retusa sulcata Vl 111 R tttt Volvulella recta 3 11 4 2 1 3 8 7 1 4 1 1 1 4 7a 6m TABLE 2 (Continued) Species Stations by Increasing Depths 15 17 20 23 25 28 30 39 63 169 260 Illus. PERACLIDAE...

Treece, Granvil D

2012-06-07

245

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

PubMed Central

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

vila, Srgio P.; Sigwart, Julia

2013-01-01

246

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

PubMed Central

Luminescent bacteria in the family Vibrionaceae (Bacteria: ?-Proteobacteria) are commonly found in complex, bilobed light organs of sepiolid and loliginid squids. Although morphology of these organs in both families of squid is similar, the species of bacteria that inhabit each host has yet to be verified. We utilized sequences of 16S ribosomal RNA, luciferase ?-subunit (luxA) and the glyceraldehyde-3-phosphate dehydrogenase (gapA) genes to determine phylogenetic relationships between 63 strains of Vibrio bacteria, which included representatives from different environments as well as unidentified luminescent isolates from loliginid and sepiolid squid from Thailand. A combined phylogenetic analysis was used including biochemical data such as carbon use, growth and luminescence. Results demonstrated that certain symbiotic Thai isolates found in the same geographic area were included in a clade containing bacterial species phenotypically suitable to colonize light organs. Moreover, multiple strains isolated from a single squid host were identified as more than one bacteria species in our phylogeny. This research presents evidence of species of luminescent bacteria that have not been previously described as symbiotic strains colonizing light organs of Indo-West Pacific loliginid and sepiolid squids, and supports the hypothesis of a non-species-specific association between certain sepiolid and loliginid squids and marine luminescent bacteria. PMID:22707847

Guerrero-Ferreira, R. C.; Nishiguchi, M. K.

2012-01-01

247

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

PubMed

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

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

2014-01-01

248

Sensory structure of the tentacles of the slug, Arion ater (Pulmonata, Mollusca)  

Microsoft Academic Search

Free nerve endings are abundant in the distal epithelium of the tentacles of Arion ater Four ultrastructurally distinct types of ending are identified from serial sections. The Type 1 free nerve ending bears a distal cup from which arise short microvilli and a few cilia. Different free nerve endings in this grouping may show considerable individual variation. The Type 2

B. R. Wright

1974-01-01

249

Sensory structure of the tentacles of the slug, Arion ater (Pulmonata, Mollusca)  

Microsoft Academic Search

The simple epithelium on the tentacle tips of th slug, Arion ater is composed, essentially, of supporting cells and sensory dendrites, and bears, at its distal surface, a brushborder of unusual structure. This brush-border is formed from the plasmatic extensions of supporting cells and the terminations of sensory dendrites. It is composed of two structurally distinct regions, an outer region

B. R. Wright

1974-01-01

250

Spermatogenesis and sperm dimorphism in land slug Arion after L. (Pulmonata, Mollusca).  

PubMed

The fine structure of spermatogonia, spermatocytes, spermatids and spermatozoa has been examined in the hermaphrodite gland of Arion ater in detail. Intercellular bridges link spermatogonia, primary and secondary spermatocytes and spermatids. The primary spermatocytes appear in groups, connected to a common cytoplasmic mass, the Cytophore. Two types of spermatids and sperm are recognized (eupyrene and apyrene). The apyrene spermatids differ from the eupyrene type, particularly in the later spermatid stage, by residual cytoplasm with many vesiculose bodies around the nucleus, which is electron-dense. The eupyrene sperm have an acrosome and DNA-histone fibers in the nucleus. Organelle function of the spermatogenic cells at different stages of differentiation, and also the occurrence of sperm dimorphism have been discussed. PMID:7195121

Parivar, K

1981-01-01

251

Arion ater (mollusca: pulmonata) as an indicator of terrestrial environmental pollution  

Microsoft Academic Search

Using X-ray energy spectroscopy concentrations of Mn, Fe, Cu, Zn, As, Br, Ph, Rb, and Sr were measured in specimens of the terrestrial gastropod, Arion ater, found in locations close to and far from a highway. Higher values of Pb and Br were observed for specimens near the polluting source and mathematical analysis revealed an inverse relationship between lead uptake

J. D. Popham; J. M. D'Auria

1980-01-01

252

Cytogenetics of the land snails Cantareus aspersus and C. mazzullii (Mollusca: Gastropoda: Pulmonata).  

PubMed

A cytogenetic study was carried out on the chromosomes and nuclear DNA contents of the land snails Cantareus aspersus and C. mazzullii (Gastropoda: Pulmonata). Chromosomes were studied using Giemsa staining, banding methods and fluorescent in situ hybridization (FISH) with three repetitive DNA probes [18S rDNA, (GATA)(n) and (TTAGGG)(n)]. Results were very similar in the two species both showing (1) 54 bi-armed chromosomes [submetacentrics (SM) + metacentrics (M) + subtelocentrics (ST)]; (2) 10 terminal NORs after sequential application of rDNA FISH and silver staining; (3) uniform DNA fluorescence with CMA(3) and DAPI staining and (4) genomic composition considerably enriched both in highly- and moderately-repeated DNAs. The telomeric (TTAGGG)(n) sequence hybridized with the termini of all of the chromosomes in the two species. In spite of their apparent karyological uniformity, flow cytometry DNA assays showed that C. aspersus and C. mazzullii are characterized by different nuclear DNA content (C values are 3.58 and 3.08 pg, respectively) and slightly different base composition in their genomes. Present data on GS and AT% in C. mazzullii and C. aspersus confirm the trend toward high GS values and GC percentages among land snails. PMID:15857774

Vitturi, Roberto; Libertini, Angelo; Sineo, Luca; Sparacio, Ignazio; Lannino, Antonella; Gregorini, Armando; Colomba, Mariastella

2005-01-01

253

Cytogenetics of Anodonta cygnea (Mollusca: Bivalvia) as possible indicator of environmental adversity  

NASA Astrophysics Data System (ADS)

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.

Carrilho, J.; Leito, A.; Vicente, C.; Malheiro, I.

2008-11-01

254

Using DNA barcoding to differentiate invasive Dreissenaspecies (Mollusca, Bivalvia)  

PubMed Central

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

Marescaux, Jonathan; Van Doninck, Karine

2013-01-01

255

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

Microsoft Academic Search

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

ALEC E. AITKEN; ROBERT GILBERT

1996-01-01

256

Annotated type catalogue of the Bulimulidae (Mollusca, Gastropoda, Orthalicoidea) in the Natural History Museum, London  

PubMed Central

Abstract The type status is described of 404 taxa classified within the family Bulimulidae (superfamily Orthalicoidea) and kept in the London museum. Lectotypes are designated for Bulimus aurifluus Pfeiffer, 1857; Otostomus bartletti H. Adams, 1867; Helix cactorum dOrbigny, 1835; Bulimus caliginosus Reeve, 1849; Bulimus chemnitzioides Forbes, 1850; Bulimus cinereus Reeve, 1849; Helix cora dOrbigny, 1835; Bulimus fallax Pfeiffer, 1853; Bulimus felix Pfeiffer, 1862; Bulimus fontainii dOrbigny, 1838; Bulimus fourmiersi dOrbigny, 1837; Bulimus (Mesembrinus) gealei H. Adams, 1867; Bulimus gruneri Pfeiffer, 1846; Bulimus humboldtii Reeve, 1849; Helix hygrohylaea dOrbigny, 1835; Bulimus jussieui Pfeiffer, 1846; Bulimulus (Drymaeus) binominis lascellianus E.A. Smith, 1895; Helix lichnorum dOrbigny, 1835; Bulimulus (Drymaeus) lucidus da Costa, 1898; Bulimus luridus Pfeiffer, 1863; Bulimus meleagris Pfeiffer, 1853; Bulimus monachus Pfeiffer, 1857; Bulimus montagnei dOrbigny, 1837; Helix montivaga dOrbigny, 1835; Bulimus muliebris Reeve, 1849; Bulimus nigrofasciatus Pfeiffer in Philippi 1846; Bulimus nitelinus Reeve, 1849; Helix oreades dOrbigny, 1835; Helix polymorpha dOrbigny, 1835; Bulimus praetextus Reeve, 1849; Bulinus proteus Broderip, 1832; Bulimus rusticellus Morelet, 1860; Helix sporadica dOrbigny, 1835; Bulimus sulphureus Pfeiffer, 1857; Helix thamnoica var. marmorata dOrbigny, 1835; Bulinus translucens Broderip in Broderip and Sowerby I 1832; Helix trichoda dOrbigny, 1835; Bulinus ustulatus Sowerby I, 1833; Bulimus voithianus Pfeiffer, 1847; Bulimus yungasensis dOrbigny, 1837. The type status of the following taxa is changed to lectotype in accordance with Art. 74.6 ICZN: Bulimulus (Drymaeus) caucaensis da Costa, 1898; Drymaeus exoticus da Costa, 1901; Bulimulus (Drymaeus) hidalgoi da Costa, 1898; Bulimulus (Drymaeus) interruptus Preston, 1909; Bulimulus (Drymaeus) inusitatus Fulton, 1900; Bulimulus latecolumellaris Preston, 1909; Bulimus (Otostomus) napo Angas, 1878; Drymaeus notabilis da Costa, 1906; Drymaeus notatus da Costa, 1906; Bulimulus (Drymaeus) nubilus Preston, 1903; Drymaeus obliquistriatus da Costa, 1901; Bulimus (Drymaeus) ochrocheilus E.A. Smith, 1877; Bulimus (Drymaeus) orthostoma E.A. Smith, 1877; Drymaeus expansus perenensis da Costa, 1901; Bulimulus pergracilis Rolle, 1904; Bulimulus (Drymaeus) plicatoliratus da Costa, 1898; Drymaeus prestoni da Costa, 1906; Drymaeus punctatus da Costa, 1907; Bulimus (Leptomerus) sanctaeluciae E.A. Smith, 1889; Bulimulus (Drymaeus) selli Preston, 1909; Drymaeus subventricosus da Costa, 1901; Bulimulus (Drymaeus) tigrinus da Costa, 1898; Drymaeus volsus Fulton, 1907; Drymaeus wintlei Finch, 1929; Bulimus zhorquinensis Angas, 1879; Bulimulus (Drymaeus) ziczac da Costa, 1898. The following junior subjective synonyms are established: Bulimus antioquensis Pfeiffer, 1855 = Bulimus baranguillanus Pfeiffer, 1853; Drymaeus bellus da Costa, 1906 = Drymaeus blandi Pilsbry, 1897; Bulimus hachensis Reeve 1850 = Bulimus gruneri Pfeiffer, 1846 = Bulimus columbianus Lea, 1838; Bulimus (Otostomus) lamas Higgins 1868 = Bulimus trujillensis Philippi, 1867; Bulimulus (Drymaeus) binominis lascellianus E.A. Smith, 1895 = Bulimulus (Drymaeus) binominis E.A. Smith, 1895; Drymaeus multispira da Costa, 1904 = Helix torallyi dOrbigny, 1835; Bulimulus (Drymaeus) plicatoliratus Da Costa, 1898 = Bulimus convexus Pfeiffer, 1855; Bulimus sugillatus Pfeiffer, 1857 = Bulimus rivasii dOrbigny, 1837; Bulimus meridionalis Reeve 1848 [June] = Bulimus voithianus Pfeiffer, 1847. New combinations are: Bostryx montagnei (dOrbigny, 1837); Bostryx obliquiportus (da Costa, 1901); Bulimulus heloicus (dOrbigny, 1835); Drymaeus (Drymaeus) lusorius (Pfeiffer, 1855); Drymaeus (Drymaeus) trigonostomus (Jonas, 1844); Drymaeus (Drymaeus) wintlei Finch, 1929; Drymaeus (Mesembrinus) conicus da Costa, 1907; Kuschelenia (Kuschelenia) culminea culminea (dOrbigny, 1835); Kusche

Breure, Abraham S.H.; Ablett, Jonathan D.

2014-01-01

257

Biology, diversity and evolution of "solarpowered" Nudibranchia (Mollusca: Gastropoda) and their symbiosis with Zooxanthellae.  

E-print Network

??Die Biologie, kophysiologie, Evolution und Diversitt "solarbetriebener" Nudibranchia und ihrer Symbiose mit Zooxanthellen wurde untersucht. Mit Hilfe eines Diving-PAM (Pulse Amplitude Modulated Fluorometer) und histologischer (more)

Burghardt, Ingo

2006-01-01

258

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

PubMed

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

Takano, Tsuyoshi; Kano, Yasunori

2014-10-01

259

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

NASA Astrophysics Data System (ADS)

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.

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

2008-12-01

260

Anatomisch-histologische Untersuchung der Kiemenretraktoren bei ausgewhlten Arten der Caudofoveata (Mollusca).  

E-print Network

??Die Caudofoveata (Schildfer) sind eine rein marine, im Schlamm grabende Molluskenklasse mit wurmhnlicher Gestalt. Wegen ihrer versteckten Lebensweise, der geringen Gre sowie ihrer Bedeutungslosigkeit fr (more)

Egger, Pia Andrea

2008-01-01

261

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

Microsoft Academic Search

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 l-1) to medium (10 to 20 particles l-1) particle

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

1992-01-01

262

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

NASA Astrophysics Data System (ADS)

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.

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

2008-12-01

263

DNA barcoding reveals neritid diversity (Mollusca: Gastropoda) diversity in Malaysian waters.  

PubMed

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

Chee, S Y; Mohd Nor, Siti Azizah

2014-12-01

264

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

NASA Astrophysics Data System (ADS)

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.

Trigg, Colin; Moore, Colin G.

2009-04-01

265

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

Microsoft Academic Search

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

J. M. Healy

1982-01-01

266

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

Microsoft Academic Search

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

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

1980-01-01

267

Quantification of midkine gene expression in Patella caerulea (Mollusca, Gastropoda) exposed to cadmium  

NASA Astrophysics Data System (ADS)

The release of cadmium into many coastal areas represents a threat to ecosystems and human health; cadmium is carcinogenic in mammals and in both marine invertebrates and vertebrates. The use of molluscs to assess the ecologic risk associated with contaminants is strongly recommended on account of their ecological role and on their highly conserved control and regulatory pathways that are often homologous to vertebrate systems. We previously identified a midkine family protein in the limpet Patella caerulea; the midkine is a recently discovered cytokines family with unequivocal informative value on repairing injury and neoplastic processes in mammals. Here we report on midkine ( mdk) and ?-tubulin ( ?-tub) gene expression patterns in P. caerulea exposed to cadmium. Limpets, collected on two occasions from a breakwater at a marina (Tyrrhenian Sea) were exposed to sublethal cadmium concentrations (0.5 and 1 mg l -1 Cd) over a 10-day exposure period. RNA was extracted from the viscera of unexposed and exposed specimens. Real time TaqMan RT-PCR was performed to measure the relative mdk and ?-tub gene expression levels. A remarkable mdk over-expression was observed in all exposed animals with respect to unexposed ones; mdk over-expression was significantly higher in both treatments when compared with un-treatment (mean expression levels: 23- and 38-fold, for 0.5 and 1 mg l -1 Cd treatment, respectively; ANOVA, for both P < 0.01). The study also indicates that the mdk up-regulation was significantly Cd-concentration dependent ( P < 0.05). A significant up-regulation of the constitutive ?-tub gene was also observed in 1 mg l -1 Cd-treated animals (mean expression level: 4-fold; ANOVA, P < 0.05). In conclusion, these data provide the first evidence paving the way for the use of the midkine as a promising new biomarker of effect in the environment risk assessment policy.

Stillitano, Francesca; Mugelli, Alessandro; Cerbai, Elisabetta; Vanucci, Silvana

2007-10-01

268

The complete mitoc genome of Scutopus ventrolineatus (Mollusca: Chaetodermomorpha) supports the Aculifera hypothesis.  

PubMed

BackgroundWith more than 100,000 living species, mollusks are the second most diverse metazoan phylum. The current taxonomic classification of mollusks recognizes eight classes (Neomeniomorpha, Chaetodermomorpha, Polyplacophora, Monoplacophora, Cephalopoda, Gastropoda, Bivalvia, and Scaphopoda) that exhibit very distinct body plans. In the past, phylogenetic relationships among mollusk classes have been contentious due to the lack of indisputable morphological synapomorphies. Fortunately, recent phylogenetic analyses based on multi-gene data sets are rendering promising results. In this regard, mitochondrial genomes have been widely used to reconstruct deep phylogenies. For mollusks, complete mitochondrial genomes are mostly available for gastropods, bivalves, and cephalopods, whereas other less-diverse lineages have few or none reported.ResultsThe complete DNA sequence (14,662bp) of the mitochondrial genome of the chaetodermomorph Scutopus ventrolineatus Salvini-Plawen, 1968 was determined. Compared with other mollusks, the relative position of protein-coding genes in the mitochondrial genome of S. ventrolineatus is very similar to those reported for Polyplacophora, Cephalopoda and early-diverging lineages of Bivalvia and Gastropoda (Vetigastropoda and Neritimorpha; but not Patellogastropoda). The reconstructed phylogenetic tree based on combined mitochondrial and nuclear sequence data recovered monophyletic Aplacophora, Aculifera, and Conchifera. Within the latter, Cephalopoda was the sister group of Gastropoda and Bivalvia+Scaphopoda.ConclusionsPhylogenetic analyses of mitochondrial sequences showed strong among-lineage rate heterogeneities that produced long-branch attraction biases. Removal of long branches (namely those of bivalves and patellogastropods) ameliorated but not fully resolved the problem. Best results in terms of statistical support were achieved when mitochondrial and nuclear sequence data were concatenated. PMID:25288450

Osca, David; Irisarri, Iker; Todt, Christiane; Grande, Cristina; Zardoya, Rafael

2014-09-25

269

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

Microsoft Academic Search

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 15C. Larval cultures

F. S. Chia; R. Koss

1978-01-01

270

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

PubMed

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.heyseana (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.elongata 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

Chichvarkhin, Anton; Chichvarkhina, Olga

2014-01-01

271

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

Microsoft Academic Search

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.

Jeffrey Levinton

1973-01-01

272

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

Microsoft Academic Search

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 head (6.58.5 m 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.

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

1981-01-01

273

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

NASA Astrophysics Data System (ADS)

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.

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

2005-05-01

274

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

NASA Astrophysics Data System (ADS)

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.

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

2010-08-01

275

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

Microsoft Academic Search

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 parasitehost inter-relationships is far from being sufficient. The family is immersed in a systematictaxonomic confusion. The necessity for a tool

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

276

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

PubMed

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

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

2014-09-18

277

A new Middle Miocene Niveria Jousseaume, 1884 (Mollusca: Gastropoda: Trivioidea) from Hungary  

NASA Astrophysics Data System (ADS)

A new species of Niveria from the Middle Miocene (Badenian) of the Paratethys of Borsodbta, 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 Galpagos.

Fehse, Dirk

2011-02-01

278

Epibiotic relationships on Zygochlamys patagonica (Mollusca, Bivalvia, Pectinidae) increase biodiversity in a submarine canyon in Argentina  

NASA Astrophysics Data System (ADS)

The continental slope of the southern SW Atlantic Ocean has many distinguishable deep submarine canyons, varying in depth and extension. The benthic fauna within one of them, detected in April 2005 by means of a multibeam SIMRAD EM1002 sonar, and located at 4335?S to 5933?W, 325 m depth, was studied to discuss faunal affinities with the neighbouring Patagonian scallop fishing grounds located at upper slope depths. In order to add faunal information to the previous general study, we studied the epibiotic species settled on Patagonian scallops (the dominant species in the area) collected in the reference sampling site using a 2.5-m mouth-opening dredge, 10 mm mesh size. We sampled 103 scallops with shell heights between 22 and 69 mm; epibionts were recorded on both valves. We found 53 epibiotic taxa, which were most conspicuous on the upper valve. Bryozoa was the most diverse group (34 species) while Polychaeta was the most abundant group, recorded on 94% of the scallops. Stylasteridae (2 species) and Clavulariidae (Cnidaria) conform newly recorded epibionts on Z. patagonica and the sponge Tedania (Tedaniopsis) infundibuliformis also represents a new record for the SW Atlantic Ocean.

Schejter, Laura; Lpez Gappa, Juan; Bremec, Claudia Silvia

2014-06-01

279

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

Microsoft Academic Search

Experimental rearing of juvenile cuttlefish was carried out in a semi-closed system for 40 days at 19C. 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

N. Koueta; E. Boucaud-Camou

1999-01-01

280

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

USGS Publications Warehouse

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.

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

1997-01-01

281

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

Microsoft Academic Search

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

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

1987-01-01

282

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

NASA Astrophysics Data System (ADS)

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.

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

2012-03-01

283

Mitochondrial genome of the endangered marine gastropod Strombus gigas Linnaeus, 1758 (Mollusca: Gastropoda).  

PubMed

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

Mrquez, Edna J; Castro, Erick R; Alzate, Juan F

2014-09-01

284

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

NASA Astrophysics Data System (ADS)

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.

Quetglas, Antoni; Ordines, Francesc; Gonzlez, Mara; Franco, Ignacio

2009-08-01

285

Size-differential feeding in Pinna nobilis L. (Mollusca: Bivalvia): Exploitation of detritus, phytoplankton and zooplankton  

NASA Astrophysics Data System (ADS)

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.

Davenport, John; Ezgeta-Bali?, Daria; Peharda, Melita; Skeji?, Sanda; Nin?evi?-Gladan, ivana; Matijevi?, Slavica

2011-04-01

286

The end of a long controversy: systematics of the genus Limenandra (Mollusca: Nudibranchia: Aeolidiidae)  

NASA Astrophysics Data System (ADS)

Limenandra Haefelfinger and Stamm 1958 is a small genus within the Aeolidiidae with, until this paper, only two species: Limenandra nodosa Haefelfinger and Stamm 1958 and Limenandra fusiformis Baba 1949. Although most recent authors have regarded Limenandra as a junior synonym of Baeolidia Bergh 1888, recent molecular studies have demonstrated its monophyletic status and have rejected the circumtropical distribution attributed to the type species, L. nodosa. The present paper reviews the previously known species of Limenandra with additional morphological data and describes three new species: Limenandra barnosii sp. nov. and Limenandra rosanae sp. nov. from the Indo-Pacific are easily distinguished from all other Limenandra species by their vivid and bright colour patterns, while Limenandra confusa sp. nov., also from the Indo-Pacific, is very similar to the Atlantic and Mediterranean L. nodosa. The five species differ in colouration, the size and ornamentation of the cerata, the rhinophorial papillae, details of the reproductive system and the number of salivary glands. Additionally, Limenandra can be easily distinguished from other Aeolidiidae based on differences in the radular and receptaculum seminis morphology.

Carmona, Leila; Pola, Marta; Gosliner, Terrence M.; Cervera, Juan Lucas

2014-03-01

287

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

NASA Astrophysics Data System (ADS)

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 lancet type.

Zabala, S.; Hermida, G. N.; Gimnez, J.

2009-09-01

288

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

Microsoft Academic Search

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

G. Haszprunar

1985-01-01

289

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

Microsoft Academic Search

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

Frank E. Anderson

2000-01-01

290

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

Microsoft Academic Search

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

C. A. Wright; D. Rollinson

1979-01-01

291

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

USGS Publications Warehouse

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.

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

2000-01-01

292

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

USGS Publications Warehouse

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.

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

2007-01-01

293

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

Microsoft Academic Search

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 (ff, fm

JEAN GEARY BOAL

1996-01-01

294

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

Microsoft Academic Search

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

Jeffrey L. Boore; Joseph L. Staton

2001-01-01

295

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

NASA Astrophysics Data System (ADS)

Submarine canyons are often viewed as natural debris 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?

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

2013-11-01

296

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

Microsoft Academic Search

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

Youn-Ho Lee; V. D. Vacquier

1995-01-01

297

Rich and rareFirst insights into species diversity and abundance of Antarctic abyssal Gastropoda (Mollusca)  

NASA Astrophysics Data System (ADS)

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.

Schwabe, Enrico; Michael Bohn, Jens; Engl, Winfried; Linse, Katrin; Schrdl, Michael

2007-08-01

298

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

SciTech Connect

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)

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

1980-11-01

299

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

Microsoft Academic Search

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

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

300

Transformation of soft coral (Coelenterata: Octocorallia) terpenes by Ovula ovum (Mollusca: Prosobranchia)  

Microsoft Academic Search

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

J. C. Coll; D. M. Tapiolas; B. F. Bowden; L. Webb; H. Marsh

1983-01-01

301

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

PubMed Central

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 Castelln 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

Delicado, Diana; Ramos, Marian A.

2012-01-01

302

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

PubMed Central

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 Assiminea 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

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

2014-01-01

303

Genetic variability and molecular identification of Brazilian Biomphalaria species (Mollusca: Planorbidae).  

PubMed

Freshwater snails belonging to the genus Biomphalaria are intermediate hosts of the trematode Schistosoma mansoni in the Neotropical region and Africa. In Brazil, one subspecies and ten species of Biomphalaria have been identified: B. glabrata, B. tenagophila, B. straminea, B. occidentalis, B. peregrina, B. kuhniana, B. schrammi, B. amazonica, B. oligoza, B. intermedia and B.t. guaibensis. However, only the first three species are found naturally infected with S. mansoni. The classical identification of these planorbids is based on comparison of morphological characteristics of the shell and male and female reproductive organs, which is greatly complicated by the extensive intra-specific variation. Several molecular techniques have been used in studies on the identification, genetic structure as well as phylogenetic relationships between these groups of organisms. Using the randomly amplified polymorphic DNAs (RAPD) analysis we demonstrated that B. glabrata exhibits a remarkable degree of intra-specific polymorphism. Thus, the genetics of the snail host may be more important to the epidemiology of schistosomiasis than those of the parasite itself. Using the simple sequence repeat anchored polymerase chain reaction (SSR-PCR) in intra-populational and intra-specific studies we have demonstrated that snails belonging to the B. straminea complex (B. straminea, B. kuhniana and B. intermedia) clearly presented higher heterogeneity. Using the low stringency polymerase chain reaction (LS-PCR) technique we were able to separate B. glabrata from B. tenagophila and B. tenagophila from B. occidentalis. To separate all Brazilian Biomphalaria species we used the restriction fragment length polymorphism (PCR-RFLP) of the internal transcribed spacer region (ITS) of the DNA gene. The method also proved to be efficient for the specific identification of DNA extracted from snail eggs. Recently we have sequenced the ITS2 region for phylogenetic studies of all Biomphalaria snails from Brazil. PMID:11769284

Carvalho, S; Caldeira, R L; Simpson, A J; Vidigal, T H

2001-01-01

304

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

NASA Astrophysics Data System (ADS)

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.

Zamarro, Maria; Garca-lvarez, Oscar; Urgorri, Victoriano

2013-09-01

305

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

NASA Astrophysics Data System (ADS)

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.

Baptista, Miguel; Repolho, Tiago; Maulvault, Ana Lusa; Lopes, Vanessa M.; Narciso, Luis; Marques, Antnio; Bandarra, Narcisa; Rosa, Rui

2014-12-01

306

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

E-print Network

merula merula Br?elia breueri Balat, 1955 Chloris chloris Br?elia conocephalus (Blag.), 1940 Sitta europaea caesia Br?elia curiucae n. sp. Sylvia curruca curruca Br?elia cyclothorax (Burm.), 1838 Passer montanus Br?elia delicata (Nitzsch...

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

1966-01-01

307

Cross-reactivity of IgE antibodies to caddis fly with arthropoda and mollusca.  

PubMed

We investigated the possibility that subjects with IgE antibodies to an inhalant insect allergen, such as caddis fly, might also have antibodies to cross-reacting carbohydrate determinants (CCDs). IgE antibodies to cross-reacting allergens in caddis flies, mussels, oysters, shrimps, crabs, honeybee, and yellow jacket venoms were determined by RAST, RAST inhibition, and immunoblot studies with sera from three different sources: (1) sera of patients with well-defined inhalant atopy to caddis fly, (2) sera with IgE anti-CCD antibodies from subjects without known exposure to caddis fly, and (3) hyperimmune antisera with IgG anti-CCD antibodies raised as a result of immunization of rabbits with grass-pollen extract, buckwheat glycoprotein, or with honeybee venom. Sera from groups 2 and 3 reacted with Sepharose-coupled caddis fly extract in a RAST-type assay and elicited virtually identical patterns on immunoblots of caddis fly extract separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, whereas the sera from group 1 atopic patients did not react with CCD-rich material. However, indications for other types of cross-reacting antibodies were detected. The IgE antibodies of one of the patients studied (who was allergic not only to caddis fly but also to shellfish) were found to detect a cross-reacting homologous protein in extracts of mussel, oyster, shrimp, crab, honeybee, and yellow jacket venom. Preliminary results suggest that this cross-reacting 13 kd protein, the most prominent caddis fly allergen, is an invertebrate hemoglobin (erythrocruorin)-like molecule. These studies suggest the possibility that patients sensitized by exposure to caddis fly antigens could develop allergic reactions during their first exposure to shellfish or to their first bee sting. PMID:2547857

Koshte, V L; Kagen, S L; Aalberse, R C

1989-08-01

308

Does polyploidy occur in central European species of the family Sphaeriidae (Mollusca: Bivalvia)?  

Microsoft Academic Search

Some representatives of the bivalve family Sphaeriidae are assumed to be polyploid. In this study, 11 sphaeriid species (nine\\u000a of the genus Pisidium, one of Musculium, and one of Sphaerium) inhabiting central Europe were studied karyologically, 10 of them for the first time. Analysis revealed high chromosome\\u000a numbers (from 140 to 240). To elucidate the origin of high chromosome numbers,

Tereza Ko?nkov; Alena Morvkov

2010-01-01

309

Bioaccumulation of heavy metals in mollusca species and assessment of potential risks to human health.  

PubMed

Along the Alexandria coast of the Egyptian Mediterranean Sea, five edible species of bivalve molluscs and one gastropoda species (Mactra coralline, Ruditapes decussates, Paphia undulate, Venerupis rhomboids, Crista pectinata and Coralliophila meyendorffi) were analyzed for content of metals (Cadmium, Chromium, Lead, Cobalt and Nickel) in the muscle and in the sediments where they live. The potential health risks of metals to humans via consumption of seafood were assessed by estimated daily intake and target hazard quotient. Significant positive correlations (p<0.05) were obtained between tissue concentrations for all pairs of metals, with the exception of Cadmium. Significant positive correlations were also obtained for the concentrations of Cd and Ni in tissues of all studied species relative to their concentrations in surface sediments. However, correlations between tissue and sediment concentrations for Chromium, Lead and Cobalt were negative. Ruditapes decussates and C. meyendorffi had the highest values for the summed target hazard quotient and may pose a potential risk to local inhabitants through their consumption in the diet. The potential risk would arise from exposure to high tissue concentrations of Cd and Pb, which exceeded published guidelines for safety of seafood products in some cases. Chromium contributed a considerable fraction of the total target hazard quotient for all metals combined, but did not exceed the published guidelines. Cobalt and Ni did not contribute greatly overall to the target hazard quotient, except in the case of Ni in V. rhomboids. PMID:23377776

Abdallah, Maha Ahmed Mohamed

2013-05-01

310

Late Paleozoic subulitacea (mollusca:gastropoda), mass extinctions and the replacement of evolutionary faunas  

SciTech Connect

Mesogastropod subulitaceans possess characteristics typical of active carnivores and occupied a trophic regime typical of the Mesozoic-Cenozoic evolutionary fauna. Despite occupying a vacant niche, subulitaceans are low in both diversity and abundance in late Paleozoic gastropod faunas. In addition, Paleozoic Archaeogastropoda and Mesogastropoda are taxonomically and functionally distinct from Mesozoic groups and display diversity dynamics typical of the Paleozoic evolutionary fauna, not the Mesozoic-Cenozoic fauna with which they were grouped by Sepkoski. Late Paleozoic gastropods are different from pre-Carboniferous taxa, but there is no preferential expansion of the major Mesozoic taxa, nor is there any pattern of exploitation of a major niche utilized by later groups but under-used by Paleozoic taxa. The high taxonomic level used Sepkoski's factor analysis neglects the finer scale of replacement and diversification. This distinct evolutionary behavior of Paleozoic gastropods may be typical of other taxa as well. It weakens the assertions of Kitchell and Carr and Sepkoksi and Miller that the replacement of evolutionary Fauna II by Fauna III began in the late Paleozoic and would have occurred even without the Guadelupian-Dzulfian mass extinction. Thus for gastropods at last, the Late Permian mass extinction did not merely speed up on ongoing process, but probably determined the evolutionary outcome.

Erwin, D.H.

1985-01-01

311

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

Microsoft Academic Search

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

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

2008-01-01

312

Evolutionary relationships of deep-sea vent and cold seep clams (Mollusca: Vesicomyidae) of the \\  

Microsoft Academic Search

Vesicomyid clams are among the dominant invertebrates of chemosynthesis-based communities found at deep-sea cold seeps and hydrothermal vents, yet there is considerable taxonomic confusion within the family Vesicomyidae. The present study examined phylogenetic relationships among vesicomyid clams belonging to a cryptic-species complex that includes Vesicomya (previously Calyptogena) pacifica (Dall, 1891) and Vesicomya lepta (Dall, 1896). Mitochondrial (mt) COI sequences from

S. K. Goffredi; L. Hurtado; S. Hallam; R. Vrijenhoek

2003-01-01

313

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

PubMed

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

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

2008-12-01

314

Phylogeny and taxonomy of the marine false limpets in the genus Siphonaria (Mollusca: Gastropoda: Siphonariidae).  

E-print Network

??Background: Reconstructing the higher relationships of pulmonate gastropods has been difficult. Morphology is problematic due to high homoplasy. Molecular studies have suffered from low taxon (more)

White, Tracy Renae

2011-01-01

315

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

PubMed Central

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

2008-01-01

316

Spatial distribution and home-range of the pest slug Arion lusitanicus (Mollusca: Pulmonata)  

NASA Astrophysics Data System (ADS)

The density and distribution of egg-batches, juveniles and adult Arion lusitanicus, as well as individual home-ranges, were investigated over two seasons. The study was performed on grassland which was mown twice a year and received no herbicides or pesticides, with neighbouring field and stream-side vegetation. Female-mature slugs preferred restricted areas closely neighbouring the taller vegetation of the stream-side vegetation and field, but less-favourable parts of the site were also inhabited in the second year when population densities increased and weather conditions were more favourable. It was postulated that slugs could have home-ranges, as homing behaviour is a well-known phenomenon. The application of a long-lasting individual marking technique enabled calculations of home-ranges (convex polygons) for slugs for the first time. Home-range size averaged 45.4 m 2 when the population density was low in 1995, and was found to be negatively correlated with density, as it decreased to 12.4 m 2 in 1996, when population density was high. Mating sites were found to be distinctly closer to the geometric centres of activity than the sites used for egg-deposition. Egg-batches were aggregated under the shelter traps (50 50 cm squares of hardboard covered with polystyrene) and the pattern of distribution of egg-batches persisted in the young hatchlings. A number of foreign A. lusitanicus were introduced into the unfavourable centre of the site, and by two to four weeks after release their distribution exactly resembled that of the local ones. In all the various aspects of behaviour investigated, large individual differences were found, suggesting a great plasticity in this generalist species. The importance of the species' dispersal capacity in relation to general ecological and applied aspects of control is discussed in the context of the present findings.

Grimm, Brigitte; Paill, Wolfgang

2001-08-01

317

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

PubMed Central

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

Nederlof, Ralf; Muller, Mees

2012-01-01

318

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

PubMed Central

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 (backfilling) 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

2013-01-01

319

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

PubMed Central

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

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

2007-01-01

320

A population study of epigean and subterranean Potamolithus snails from southeast Brazil (Mollusca: Gastropoda: Hydrobiidae)  

Microsoft Academic Search

Population and reproductive biology of four Potamolithus species, two epigean (P. ribeirensis and Potamolithus sp. 1) and two subterranean (P. troglobius and Potamolithus sp. 2), from the Upper Ribeira Valley, southeast Brazil, were studied, from June 1996 to June 1997, using 1m2 quadrats and counting all individuals found in these quadrats. P. ribeirensis showed the highest variation in population densities

Maria Elina Bichuette; Eleonora Trajano

2003-01-01

321

What explains the invading success of the aquatic mud snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca)?  

Microsoft Academic Search

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

A. Alonso; P. Castro-Dez

2008-01-01

322

Evolutionary position of Peruvian land snails (Orthalicidae) among Stylommatophora (Mollusca: Gastropoda)  

Microsoft Academic Search

The genera Bostryx and Scutalus (Orthalicidae: Bulimulinae) are endemics from South America. They are mainly distributed on the western slopes of the Peruvian Andes. The goal of the present work was to assess their evolutionary position among the stylommatophoran gastropods based on the 16S rRNA mitochondrial marker. Four sequences were obtained, and along with 28 sequences of other Stylommatophora retrieved

Jorge Ramirez; Rina Ramrez; Pedro Romero; Ana Chumbe; Pablo Ramrez

2009-01-01

323

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

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

324

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

E-print Network

Charlottenlund, Denmark 3 School of Forest Resources, Penn State University, 12 Ferguson Building, University cultured and bred Bulinus nyassanus, endemic to Lake Malawi and an intermedi- ate host of Schistosoma of Schistosoma haema- tobium in the open waters of Lake Malawi. The artifi- cial culture of B. nyassanus

Boyer, Elizabeth W.

325

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

E-print Network

Nassarius acutus Snail C Planktonic Snails C 0 C C 0 0 0 A A R R 0 0 0 R C 0 0 R C A A A (sore than 100/saapling dsy) C (10 to 100/saapling dsy) R (1 to 10/sespling dsy) 0 (less than 1/saapling dsy) 1 1 0 2 2 1 1 0 3 2 1 1 0 0 1 2 1 0 0 0 0... 3 1 1 3 0 R R R R R C C 0 R R 0 C R R C R A C R C 0 C 3 3 0 0 R R B 0 0 R R R R R ~Ce ~BR@a Lolliguncula brevis ~Ga ~ro Crepidula plena Rpitonium rupicola Bassarius acutus Bassarius vibex Heritina reel ivata Betusa...

Jones, John Arthur

2012-06-07

326

New records and new species of cones from deeper water off Fiji (Mollusca, Gastropoda, Conidae)  

Microsoft Academic Search

A little less than 100 species of cones are known in the literature from waters around the Fiji islands, all intertidal to subtidal. We report here on the species taken by recent offshore and deep-water benthic sampling expeditions. Samples were taken to depths of 1300 m, although cones were taken not deeper than 680 m. Leaving aside two taxa of

R. G. Moolenbeek; D. Rckel; P. Bouchet

2008-01-01

327

New records of Conidae (Mollusca: Gastropoda) from the New Zealand region  

Microsoft Academic Search

Conus howelli Iredale is recorded from New Zealand. C. howelli and C. raoulensis Powell are considered to be very closely related, and Kermasprella Powell is thus probably a svnonvm of Endemoconus Iredale. C. teramachii (Kuroda) and C. smirna Bartsch ' Rehder are recorded from off northern New Zealand, and the known range of C. kermadecensis Iredale is extended southward.

B. A. Marshall

1981-01-01

328

The evolutionary and biomechanical implications of snout and proboscis morphology in Caenogastropoda (Mollusca: Gastropoda)  

Microsoft Academic Search

The caenogastropod proboscis is a complex morphological adaptation to a carnivorous diet. This comparative morphological investigation of proboscis and snout anatomy in Caenogastropoda shows that there is undescribed diversity in both snout\\/proboscis wall composition and introversion\\/retraction musculature. There is morphological evidence which suggests that a proboscis evolved separately in at least four separate caenogastropod groups, each characterized by the presence

Rosemary E. Golding; Winston F. Ponder; Maria Byrne

2009-01-01

329

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

PubMed Central

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 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

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

2013-01-01

330

Typhlosyrinx -like tropical deep-water turriform gastropods (Mollusca, Gastropoda, Conoidea)  

Microsoft Academic Search

Based on radular and protoconch morphology, the genus Typhlosyrinx Thiele, 1925 has been successively classified in the subfamily Turriculinae of the family Turridae and in the subfamily Clathurellinae of the family Conidae. It is shown that the protoconch had earlier been misinterpreted, and the presence of a diagonally cancellated sculpture indicates a placement in the conid subfamily Raphitominae. Two conchologically

P. Bouchet; A. Sysoev

2001-01-01

331

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

PubMed Central

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 speciesthose living between the intertidal and 50?m depth, and deep speciesthose 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

vila, Srgio P.; Goud, Jeroen; de Frias Martins, Antnio M.

2012-01-01

332

Fine structure of the germinating cells during the spermiogenesis of Arion rufus (Mollusca, Pulmonate Gastropoda).  

PubMed

Changes in spermatozoan ultrastructure have been studied during spermiogenesis of the slug Arion rufus (Gastropoda, Pulmonata, Stylommatophora). The ovotestis was investigated during the male stage, definite by the presence of spermatozoa. Some peculiar characteristics are shown by early spermatids: Around the nucleus, the nuclear envelope presents two thick layers located on opposite sides, the apical and basal plates, that will determine the antero-posterior axis of the spermatid. The chromatin, first dispersed throughout the nucleoplasm gives later on thick filaments which become attached over the inner surface of these plates. The chromatin filaments are then arranged parallel to the anteroposterior axis as the nucleus elongates. The position of the plates determines the antero-posterior axis of the spermatid. In the mature spermatozoa, the chromatin is more condensed and the nucleus presents an helical organization. The acrosome and flagellum are respectively attached externally to the center of the apical and basal plates. The acrosome consists of a membrane-bound vesicle and forms a column of homogeneous material. In the middle piece, the mitochondria have been transformed into a mitochondrial derivate by the way of a complicated metamorphosis. The axoneme is surrounded by three mitochondrial helices but only one of them contains glycogene granules. PMID:9052940

Pastisson, C; Lacorre, I

1996-04-01

333

Gonad development during the early life of Octopus maya (Mollusca: Cephalopoda).  

PubMed

Gonad development during the early life of Octopus maya is described in terms of histological, morphometric, oocytes growth, and somatic-oocyte relationship data obtained from octopus cultured at the UMDI-UNAM, in Sisal, Yucatan, Mexico. This study is the first publication on gonad development during the early life of Octopus maya. A total of 83 O. maya specimens were used; their sizes ranged from 6.5 to 76 mm of total length (TL), 4 to 28 mm of dorsal mantle length (DML), 2.5 to 20 mm of ventral mantle length (VML), and 0.0180 to 7.2940 g of fixed body weight (fBW). Animals were weighed and measured only after preservation. A loss of 10% of living weight was estimated for juvenile octopuses after formalin preservation. The relation of length to weight (VML, DML, TL/fBW) pooled for both sexes had a strong positive correlation (r), as shown by a potential power function that was quite close to 1. Compound images were produced from numerous microscopic fields. The histological examination revealed that, 4 months after hatching, male octopus (24.5 mm DML and 7.2940 g fBW) were in gonad stages 2 (maturing) to 3 (mature), with spermatogonia and spermatocytes in the tubule wall and abundant spermatids and spermatozoa in the central lumen of the seminiferous tubules, suggesting the occurrence of different phases of gonad development at different maturity stages. In contrast, females (22.5 mm DML and 4.8210 g fBW) at the same time since hatching were immature (stage 1), with many oogonia, few oocytes, and germinal epithelium. This suggests that males reach maturity earlier than females, indicating a probable onset of maturity for males at around 4 months of culture or 8 g of wet body weight. Our results indicate the possibility that the size-at-weight can be recognized early with a degree of certainty that allows the sexes to be separated for culture purposes; but more detailed studies on reproduction in relation to endocrinology and nutrition are needed. PMID:19218496

Avila-Poveda, Omar Hernando; Colin-Flores, Rafael Francisco; Rosas, Carlos

2009-02-01

334

Anteproyecto Eva Morodo Lasa Diseo e implementacin de nuevas  

E-print Network

proyecto se dividirá en los siguientes apartados: · Repaso de conceptos: se estudiarán los fundamentos redes y la Cámara Anecoica de la EPS-UAM: se medirán las características radioeléctricas de las antenas

Autonoma de Madrid, Universidad

335

Nuevas Adquisiciones [y] Resumenes (Recent Acquisitions and Abstracts).  

ERIC Educational Resources Information Center

This bibliography lists over 130 publications, books, and articles recently acquired by the Colombian National Center for Documentation and Pedagogical Information concerning a variety of educational topics. The acquisitions are listed alphabetically under subject headings; publications from many countries are included. Several of the entries are

Informacion Bibliografica Educativa, 1971

1971-01-01

336

Retencin escolar. Un camino hacia una nueva escuela  

Microsoft Academic Search

Basndose en el proyecto Fomento a la retencin escolar, realizado en el ao 2000 por la Alcalda Mayor de Bogot, D. C., por intermedio del Ministerio de Educacin, los investigadores conceptualizan el fenmeno de la desercin escolar un aporte que se constituye en radiografa de la situacin que enfrentan las instituciones en Colombia.

Cecilia Dimat Rodrguez

337

Nuevas y viejas adicciones: implicaciones para la salud pblica  

Microsoft Academic Search

According to certain authors, any pleasure giving behaviour may become a habit, and depending on the circumstances, an addiction. The objective of this study is to examine the situation of addictions in Spain and the responses generated by health policies. In recent years, both the type and pattern of drug consumption in Spain, has undergone a noticeable change.Studies of the

Mara Teresa Brugal; Alicia Rodrguez-Martos; Joan R. Villalb

2006-01-01

338

Neuroimagen en la enfermedad de Alzheimer: nuevas perspectivas  

PubMed Central

Introduccin y desarrollo En los prximos 50 aos vamos a presenciar un incremento significativo de la poblacin mayor de 65 aos y por lo tanto va a aumentar, considerablemente, el nmero de individuos con riesgo de desarrollar demencias neurodegenerativas, especialmente la enfermedad de Alzheimer (EA). Las estrategias actuales de tratamiento farmacolgico y no farmacolgico se han centrado en las fases sintomticas de esta enfermedad y, gradualmente, vamos teniendo una mayor comprensin de los posibles factores de riesgo del sndrome clnico. Conclusiones Los estudios de neuroimagen han sido muy tiles para mostrar los cambios estructurales del envejecimiento normal y patolgico, as como tambin los factores de riesgo para la EA. Los tratamientos apropiados de los factores de riesgo y su posible combinacin con tratamientos especficos para la EA podran prolongar el perodo presintomtico 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

Becker, James T.

2012-01-01

339

El teatro colombiano: Caleidoscopio de nuevos rostros, nuevas voces  

E-print Network

teatro empresa tom gran fuerza y pas al primer plano. En consecuencia, ya para los 90 se desbarataron muchos grupos, las salas empezaron a trabajar independientemente y el movimiento teatral perdi cohesin. Creci la supremaca del director y surgi... empez a apreciar un teatro producto de una mentalidad colonizada, en el que abundaban ms los espectculos que los textos y donde se adverta el afn de calcar lo visto en el Festival Iberoamericano. En otras palabras, pas de moda lo social en lo...

Garavito, Lucí a

2000-10-01

340

BIOLOGA MOLECULAR: LA NUEVA FRONTERA Por EDUARDO CADENAS  

E-print Network

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

Escolano, Francisco

341

Computacin UbicuaComputacin Ubicua Una nueva tcnica de computacin distribuidaUna nueva tcnica de computacin distribuida  

E-print Network

Computacional: qué es?Grid Computacional: qué es? Otros términos usados: Metasistemas, Metacomputación, Sistemas disponibilidad #12;Grid Computacional: qué es?Grid Computacional: qué es? Ambientes que integran, a través de. #12;Grid Computacional: qué es?Grid Computacional: qué es? Los GRIDS hacen posible el compartir

Cardinale Villarreal, Yudith C.

342

Computacin UbicuaComputacin Ubicua Una nueva tcnica de computacin distribuida Una nueva tcnica de computacin distribuida  

E-print Network

Grids ­ Teragrid Backplane #12;Grid Computacional: qué es?Grid Computacional: qué es? Otros términos usados alto desempeño y alta disponibilidad #12;Grid Computacional: qué es?Grid Computacional: qué es la provee el middleware. #12;Grid Computacional: qué es?Grid Computacional: qué es? Los GRIDS hacen

Cardinale Villarreal, Yudith C.

343

Informe Anual a la Nacin sobre el Estado del Cncer, de 1975 a 2010, con una seccin especial sobre la prevalencia de comorbilidad y su efecto en la supervivencia de personas con cncer de pulmn, seno, prstata o colorrectal: preguntas y respuestas  

Cancer.gov

El Informe Anual a la Nacin sobre el Estado del Cncer (1975 a 2010), mostr un descenso ms acelerado que en aos anteriores de los ndices de mortalidad por cncer de pulmn. Tambin contiene una seccin especial que destaca los efectos significativos que tienen otras enfermedades en la supervivencia de pacientes con cncer.

344

Molluscum Contagiosum (For Parents)  

MedlinePLUS

... more small growths or wart-like bumps (called mollusca) that are usually pink, white, or skin-colored. ... the small round pink, white, or skin-colored mollusca on the skin. These bumps are filled with ...

345

Journal of species lists and distribution NotesoNGeoGraphicDistributioN  

E-print Network

southward. 1 Zoologische Staatssammlung München, Mollusca Sektion, Münchhausenstr. 21, 81247, München and Alberto Lindner3 Mollusca, Nudibranchia: New records and southward range extensions in Santa Catarina

Floeter, Sergio Ricardo

346

Naturwissenschaften (2005) 92: 504515 DOI 10.1007/s00114-005-0045-2  

E-print Network

/ 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

Davison, Angus

347

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

348

Amer. Malac. Bull. 32(1): 135 (2014) Overview of the North American terrestrial gastropod fauna*  

E-print Network

volume of the "Land Mollusca of North America (North of Mexico)" by Henry Pilsbry in 1948, this fauna for the Mollusca of the United States and Canada published by the American Fisheries Society (Turgeon et al. 1988

Nekola, Jeffrey C.

349

Molluscan Research 28(2): 111122 Magnolia Presshttp://www.mapress.com/mr/  

E-print Network

of Placostylus (Mollusca: Gastropoda: Bulimulidae) in New Caledonia FABRICE M. BRESCIAA,B,D , CHRISTINE M Placostylus (Mollusca: Gastropoda: Bulimulidae) de la Nouvelle-Calédonie Résumé Les escargots terrestres du

Robertson, Alastair

350

BioMed Central Page 1 of 13  

E-print Network

Research article Comparative genomics of vesicomyid clam (Bivalvia: Mollusca) chemosynthetic symbionts Irene LG@fas.harvard.edu * Corresponding author Abstract Background: The Vesicomyidae (Bivalvia: Mollusca) are a family of clams that form

Girguis, Peter R.

351

INSTITUTE OF PHYSICS PUBLISHING BIOINSPIRATION & BIOMIMETICS Bioinsp. Biomim. 1 (2006) S57S64 doi:10.1088/1748-3182/1/4/S08  

E-print Network

belong to the diverse phylum Mollusca. However, this is not their only similarity. These marine animals are also jet-propelled swimmers. The Cephalopoda, including squid, are a successful group of the Mollusca

Mohseni, Kamran

352

Original article The development of tissue lesions in the snail  

E-print Network

/ Mollusca / niclosamide / Lymnaea glabra Résumé ― Le développement des lésions tissulaires chez le / glande digestive / gonade / histopathologie/Mollusca / Niclosa- mide / rein /Lymnaea glabra INTRODUCTION

Paris-Sud XI, Université de

353

Mitochondrial Pseudogenes Are Pervasive and Often Insidious in the Snapping Shrimp Genus Alpheus  

E-print Network

in length). In other cases, clear double peaks were observed in both ' Present address: Mollusca Research for correspondence and reprints: S. T. Williams, Mollusca Research Group, Department of Zoology, Natural History

Bermingham, Eldredge

354

Limnetica, 29 (2): x-xx (2011)Limnetica, 32 (1): 107-120 (2013) c Asociacin Ibrica de Limnologa, Madrid. Spain. ISSN: 0213-8409  

E-print Network

impacts on microbial communities Invasive species in the phylum Mollusca, including gastropods invasoras del phyllum Mollusca, incluyendo los gasterópodos y bivalvos, han causado impactos importantes en

Olden, Julian D.

355

Differential gene expression in bacterial symbionts from loliginid squids demonstrates variation between mutualistic and  

E-print Network

and loliginid squids (Mollusca: Cephalopoda). Despite the existence of multiple strain colonization between of the light organs of bobtail squids in the genus Euprymna (Mollusca: Cephalopoda) (Jones and Nishiguchi,

McFall-Ngai, Margaret

356

Amer. Malac. Bull. 32(2): 225235 (2014) http://www.bioone.org/toc/malb/32/2 Overview of the North American terrestrial gastropod fauna*  

E-print Network

of the last volume of the "Land Mollusca of North America (North of Mexico)" by Henry Pilsbry in 1948 for the Mollusca of the United States and Canada published by the American Fisheries Society (Turgeon et al. 1988

Nekola, Jeffrey C.

357

Small, mostly single-celled eukaryotes Polyphyletic -"Protista" is not a good name  

E-print Network

Eumetazoa Metazoa Porifera Cnidaria Ctenophora Ectoprocta Brachiopoda Echinodermata Chordata Platyhelminthes Ctenophora Cnidaria Acoela Echinodermata Chordata Platyhelminthes Rotifera Ectoprocta Brachiopoda Mollusca

358

Clitellum, Cocon, Coelome, Cuticule, Endoderme, Errant, Hmoglobine, Hirudinae, Homologie srielle, Msoderme, Mtamre, Mtamrisation, Monoque, Mouvement  

E-print Network

Tardigrada Nematomorpha Nematoda Priapulida Kinorhyncha Loricifera Echinodermata Hemichordata Chordata Arthropoda Mollusca Chordata Playhelminthes Nematoda Annelida Porifera Echinodermata autre 3 Eucoelomate

Blouin-Demers, Gabriel

359

Process for oxidizing semiconducting compounds, especially gallium arsenide  

SciTech Connect

In order to provide a semiconductive substrate such as gallium arsenide with an oxide layer, the substrate is positively biased in a plasma reactor in which an oxidizing gas is ionized by radiofrequency excitation while the substrate is heated to an elevated temperature increasing its conductivity. The substrate may be placed for this purpose on a graphite pedestal which is inductively heated from the same radiofrequency source.

Centronio, A.

1984-02-21

360

Tire-to-Surface Friction Especially Under Wet Conditions  

NASA Technical Reports Server (NTRS)

The results of measurements of the maximum friction available in braking on various runway surfaces under various conditions is shown for a C-123B airplane and comparisons of measurements with a tire-friction cart on the same runways are made. The.results of studies of wet-surface friction made with a 12-inch-diameter low-pressure tire on a tire-friction treadmill, with an automobile tire on the tire-friction cart, and with a 44 x 13 extra-high-pressure type VII aircraft tire at the Langley landing-loads track are compared. Preliminary results of tests on the tire-friction treadmill under wet-surface conditions to determine the effect of the wiping action of the front wheel of a tandem-wheel arrangement on the friction available in braking for the rear wheel are given.

Sawyer, Richard H.; Batterson, Sidney A.; Harrin, Eziaslav N.

1959-01-01

361

MORE COFFEE TALK Coffee is consumed especially by scien-  

E-print Network

reading for anyone who enjoys science with their eating and drinking. Bruce Bayly Tucson, Ariz. THE MATH Journal article, I was interested to read that "Malaria Strikes Growing Number of U.S. Travel- ers." I and related insecticides. Although I am aware of the impact DDT had on wildlife and particularly on rap- tors

Rose, Michael R.

362

Approaches to Costing Adult Literacy Programmes, Especially in Africa  

ERIC Educational Resources Information Center

Background: This study was originally prepared for the African Inter-Ministerial Conference on Literacy (September 2007) with the objective of analysing the costs of successful adult literacy programmes run both by government ministries, as well as international and national non-governmental organisations. Objectives: This study aims to increase

Carr-Hill, Roy; Roberts, Fiona; Currie, Elizabeth

2010-01-01

363

Water is Vital--Especially after a Disaster (Spanish)  

E-print Network

ER-030S 10-07 El agua es vital ? especialmente despu?s de un desastre La deshidrataci?n tiene lugar cuando el cuerpo pierde demasiada agua. Cuando usted deja de tomar agua, sus c?lulas y tejidos pierden fluidos esenciales, sus m?sculos comienzan... a cansarse y puede sufrir calambres en las piernas o sentirse d?bil. La deshidrataci?n extrema puede colapsar los vasos sangu?neos. Una persona normalmente activa necesita beber al menos 2 cuartos de gal?n de agua por d?a. En un ambiente caluroso...

Crocker, Andrew

2007-10-08

364

PRODUCTO, PRODUCCIN, PRODUCIR (CONCEPTOS: ESPECIAL REFERENCIA AL TURISMO)  

Microsoft Academic Search

Desde hace algunos aos se ha puesto de moda el uso de la palabra producto. Antes se hablaba de bienes o de mercancas pero ahora se prefiere producto. Tanto que incluso se habla del producto Espaa, por ejemplo. Lo ms curioso es que el producto o la produccin, son dos sustantivos que derivan del verbo producir, uno de los verbos

Francisco Muoz de Escalona

2010-01-01

365

Water is Vital--Especially after a Disaster  

E-print Network

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....

Crocker, Andrew

2005-10-10

366

Necrotizing Fasciitis: A Rare Disease, Especially for the Healthy  

MedlinePLUS

... chances of getting necrotizing fasciitis (??flesh-eating? bacteria) are extremely low . Necrotizing fasciitis is a serious ... be caused by more than one type of bacteria. These include group A Streptococcus (group A strep), ...

367

Especial INTERNACIONALIZACIN DE LA UA INFORMACINDOMINGO, 30 DE JUNIO, 201336  

E-print Network

doctorado, en títulos de grado a través de Erasmus y más a través acuer- dos de movilidad no europea incre- mentado de forma espectacular la demanda para movilidad no europea. En total participaron en intercambio Erasmus es- tudiantes pero, en programas de movilidad no europea la deman- da se ha quintuplicado

Escolano, Francisco

368

INTERNACIONALIZACIN UA Especial INFORMACIN DOMINGO, 30 DE JUNIO, 2013 37  

E-print Network

, Movilidad eInserciónLaboral(OPEMIL),en colaboración con los servicios propios de la UA. Han implanta- do- tranjeraspodríancursarsusestu- dios. La movilidad internacional se direcciona principalmente a los países anglosajones y nórdi- les para facilitar la movilidad de los estudiantes Enfermería y Nu- trición Humana y Dietética, y del

Escolano, Francisco

369

Consciousness: a neural capacity for objectivity, especially pronounced in humans  

PubMed Central

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 brains 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 just 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 brains pervasive tendency to objectify may be responsible for wrongly equating consciousness with feelings and wrongly opposing it to well-learned or habitual (unconscious) patterns of perception and behavior. PMID:24672506

Dijker, Anton J. M.

2014-01-01

370

Factors influencing the supercooling of tropical Arthropoda, especially locusts  

Microsoft Academic Search

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

J. L. Cloudsley-Thompson

1973-01-01

371

rgano informativo del Colegio de Ciencias y Humanidades Suplemento especial  

E-print Network

Número 3 9 de mayo de 2011 ?rgano informativo del Colegio de Ciencias y Humanidades SuplementoCCHSuplementoespecialnúmero3,9demayode20114 La Dirección General del Colegio de Ciencias y Humanidades, a través del elementos básicos del método epidemi- ológico para su aplicación en curso de Ciencias de la Salud, del nivel

Islas, León

372

Graph analysis of dream reports is especially informative about psychosis  

NASA Astrophysics Data System (ADS)

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.

Mota, Natlia B.; Furtado, Raimundo; Maia, Pedro P. C.; Copelli, Mauro; Ribeiro, Sidarta

2014-01-01

373

Designed Especially for Students of INJURY AND SICKNESS  

E-print Network

plan of a parent's employer or under a parent's individual health insurance policy if you are under the age of 26. Contact the plan administrator of the parent's employer plan or the parent's individual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Accidental Death and Dismemberment Benefits

Subramanian, Venkat

374

Miniature capacitive accelerometer is especially applicable to telemetry  

NASA Technical Reports Server (NTRS)

Capacitive accelerometer design enables the construction of highly miniaturized instruments having full-scale ranges from 1 g to several hundred g. This accelerometer is applicable to telemetry and can be tailored to cover any of a large number of acceleration ranges and frequency responses.

Coon, G. W.; Harrison, D. R.

1966-01-01

375

Most drivers, especially scooter drivers, are quite familiar with  

E-print Network

acceleration of the driver in relation to the vehicle, which arouses a feeling as if pulled back or launched in scooter · No sensors or actuators needed · Applicable to vehicles with two, three and four wheels back and forth inside or on their vehicle, during changes in velocity. A team of TU Delft scientists

Langendoen, Koen

376

Why Is It Important to Eat Grains, Especially Whole Grains?  

MedlinePLUS

... sources of many nutrients, including dietary fiber , several B vitamins (thiamin, riboflavin, niacin, and folate), and minerals ( iron , ... a feeling of fullness with fewer calories. The B vitamins thiamin, riboflavin, and niacin play a key role ...

377

Milk of Northern Fur Seal: Composition, Especially Carbohydrate and Protein  

Microsoft Academic Search

The milk of northern fur seal was analyzed with special interest in carbo- hydrate and protein. High solids (61%) and fat (45.6%) were characteristics of its gross composition. Fatty acid distribution showed that more than 22% of the fatty acids had carbon chains longer than 20 and that approximately 70% contained one or more double bonds. Analysis of free sugars

Shunichi Dosako; Shinchi Taneya; Toshiaki Kimura; Toshihiro Ohmori; Hiroaki Daikoku; Noriko Suzuki; Junichi Sawa; Kazuhiko Kano; Sumio Katayama

1983-01-01

378

Especies Anillo: Demonstraciones Inusuales de Especiaci³n  

NSDL National Science Digital Library

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 speciesâ traits.

Darren Irwin (Lund University, Sweden;)

2009-09-09

379

Maximum Entropy for Hypothesis Formulation, Especially for Multidimensional Contingency Tables  

Microsoft Academic Search

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 $m - r$ (\\

I. J. Good

1963-01-01

380

Progress Lags in High School, Especially for Advanced Achievers  

ERIC Educational Resources Information Center

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

Education Digest: Essential Readings Condensed for Quick Review, 2012

2012-01-01

381

THE VASCULAR CHANGES OF TUBERCULOUS MENINGITIS, ESPECIALLY THE TUBERCULOUS ENDARTERITIES  

PubMed Central

1. In tuberculosis meningitis there is a tuberculosis endarteritis characterized by the formation of intimal tubercles and a diffuse subendothelial, intimal proliferation due to implantation of tubercle bacili from the blood. From the endarteritis the infiltration may spread into the muscular coat and the adventitia, and the whole wall may undergo caseous and hyaline degeneration. 2. Tuberculous proliferation in the adventitia may invade the media and the intima, and the whole wall of the arterial segment may undergo degeneration. 3. The veins are constantly the seat of more or less extensive infiltration, which always results from adjacent extravascular or arterial foci. 4. The epithelioid cells of the subendothelial, tuberculous intimal See PDF for Structure proliferation are most likely derived from the subendothelial layer of connective tissue and not from the endothelial lining. PMID:19866790

Hektoen, Ludvig

1896-01-01

382

letters to nature NATURE |VOL 410 |22 MARCH 2001 |www.nature.com 463  

E-print Network

±358 (1995). 3. Ivanov, D. L. in Origin and Evolutionary Radiation of the Mollusca (ed. Taylor, J. D.) 59±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

Bolnick, Daniel I.

383

Molluscan shell evolution with review of shell calcification hypothesis Takeshi Furuhashi a,  

E-print Network

Keywords: Mollusca Shell Biomineralization Aculiferan Biomineralization research on mollusc shells has years ago, the individual components have not been well scrutinized. Besides that, Mollusca himself erected the "Mollusca" as a designation around 1788­1800. The studies on molluscs initially dealt

Miksik, Ivan

384

Biostratigraphy Geology 331  

E-print Network

03/CG2009_A03_Fig_01.htm Forams and Diatoms Ammonites #12;Phylum Mollusca, Class Cephaplopoda, a goniatitic ammonoid with a simple suture pattern #12;Phylum Mollusca, Class Cephaplopoda, a ceratitic ammonoid with a more complex suture #12;Phylum Mollusca, Class Cephaplopoda, an ammonitic ammonoid

Kammer, Thomas

385

JMBA Global Marine Environment 23 Horse mussel (Modiolus modiolus) reef seen obliquely using interpreted multibeam data  

E-print Network

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

Watson, Andrew

386

Evidence for a clade composed of molluscs with serially repeated structures: Monoplacophorans  

E-print Network

are among the rarest members of the phylum Mollusca. Previously only known from fossils since the Cambrian as it allows for new interpretations for primitive seg- mentation in molluscs. Antarctica deep sea Mollusca on the dorsal side (3). Monoplacophorans are perhaps the least known members of the phylum Mollusca. They have

Nishiguchi, Michele

387

Long-term effects of ammonia on the behavioral activity of the aquatic snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca).  

PubMed

An appropriate approach to assess the effect of toxicants on aquatic animals is to monitor behavioral endpoints, as they are a link between physiological and ecological processes. A group that can be exposed long-term to low toxic concentrations is benthic macroinvertebrates, as their mobility in aquatic ecosystems is relatively limited. Therefore, the study of behavioral long-term effects in this group is suitable from an ecological point of view, as behavioral effects can appear before mortality. During the last decades there has been an increase in ammonia concentrations in freshwater ecosystems, threatening aquatic animals. The present study focuses on the long-term effects (40 days) of nonionized ammonia on the behavioral activity of the aquatic snail Potamopyrgus antipodarum. One control and three ammonia concentrations (0.02, 0.07, and 0.13 mg N-NH(3)/L) were used in triplicate, and the activity of snails (as mean time to start normal movement) and immobility were recorded for each treatment after 0, 10, 20, 30, and 40 days of continuous exposure to nonionized ammonia. The results show that P. antipodarum presented a high tolerance to lethal long-term effects of nonionized ammonia, as no animal died during the bioassay. However, the behavioral activity of snails was a very sensitivity endpoint, as a mean nonionized ammonia concentration of 0.07 mg N-NH(3)/L affected P. antipodarum. The results are discussed and compared with the available literature on long-term effects of ammonia on freshwater macroinvertebrates. Additionally, the ammonia water quality criteria, NOECs, LOECs, and long-term LCs are discussed on the basis of the current available data for freshwater macroinvertebrates. PMID:19039513

Alonso, Alvaro; Camargo, Julio A

2009-05-01

388

Evolutionary Pattern and Process within the Vertigo gouldii (Mollusca: Pulmonata, Pupillidae) group of minute North American Land Snails  

PubMed Central

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

Nekola, Jeffrey C.; Coles, Brian F.; Bergthorsson, Ulfar

2010-01-01

389

Freshwater snails (Mollusca: Gastropoda) from the Commonwealth of Dominica with a discussion of their roles in the transmission of parasites  

E-print Network

(=Planorbella) trivolvis (Say, 1817), Melanoides tuberculata (Müller, 1774), Neritina punctulata Lamarck, 1816 and H. trivolvis are established on Dominica, West Indies. We tested a limited number of M. tuberculata

Dillon, Robert T.

390

Freshwater snails (Mollusca: Gastropoda) from the Commonwealth of Dominica with a discussion of their roles in the transmission of parasites  

Microsoft Academic Search

We collected six species of freshwater snails from Dominica, including Biomphalaria kuhniana (Clessin, 1883), Gundlachia radiata (Guilding, 1828), Helisoma (=Planorbella) trivolvis (Say, 1817), Melanoides tuberculata (Mller, 1774), Neritina punctulata Lamarck, 1816, and Physa marmorata Guilding, 1828. Our collections indicate that un-reported species such as G. radiata and H. trivolvis are established on Dominica, West Indies. We tested a limited number

Will K. Reeves; Robert T. Dillon; Gregory A. Dasch

2008-01-01

391

First abyssal record of Stenosemus exaratus (G.O.Sars, 1878) (Mollusca, Polyplacophora) intheNorth-Atlantic Ocean  

PubMed Central

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

Allcock, Louise; Schwabe, Enrico

2013-01-01

392

"First" abyssal record of Stenosemus exaratus (G.O.Sars, 1878) (Mollusca, Polyplacophora) intheNorth-Atlantic Ocean.  

PubMed

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

Allcock, Louise; Schwabe, Enrico

2013-01-01

393

Karyology of the Antarctic chiton Nuttallochiton mirandus (Thiele, 1906) (Mollusca: Polyplacophora) with some considerations on chromosome evolution in chitons.  

PubMed

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

Odierna, Gaetano; Aprea, Gennaro; Barucca, Marco; Biscotti, Maria Assunta; Canapa, Adriana; Capriglione, Teresa; Olmo, Ettore

2008-01-01

394

Marine Mollusca of isotope stages of the last 2 million years in New Zealand. Part 3. Gastropoda (Vetigastropoda - Littorinimorpha)  

Microsoft Academic Search

Three new species: Grandicrepidula hemispherica (Nukumaruan, S Hawke's Bay), Pelicariagranttaylori (Mangapanian-early Nukumaruan, Wanganui Hawke's bay), Pelicaria arahura (Waipipian-early Mangapanian, Westland and Hawke's Bay). Drawings of marine species in Smith's (1874) three plates of New Zealand molluscan types are republished. Further Australian molluscs in Wanganui Basin: Sabia australis (Lamarck), Clanculus plebejus (Philippi), both early Nukumaruan. Further northern New Zealand mollusc

AG Beu

2010-01-01

395

New lucinid bivalves from shallow and deeper water of the Indian and West Pacific Oceans (Mollusca, Bivalvia, Lucinidae)  

PubMed Central

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

Taylor, John D.; Glover, Emily A.

2013-01-01

396

Extensive population subdivision of the cuttlefish Sepia officinalis (Mollusca: Cephalopoda) around the Iberian Peninsula indicated by microsatellite DNA variation  

Microsoft Academic Search

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

M Prez-Losada; A Guerra; G R Carvalho; A Sanjuan; P W Shaw

2002-01-01

397

Principal features of the mating system of a large spawning aggregation of the giant Australian cuttlefish Sepia apama (Mollusca: Cephalopoda)  

Microsoft Academic Search

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

K. Hall; R. T. Hanlon

2002-01-01

398

Some effects of heavy metals and polychlorinated biphenyls on the estuarine organisms Brachidontes recurvus (Mollusca) and Penaeus setiferus (Crustacea  

E-print Network

days of exposure to two concentrations of mercury . . . . . . . . . . . . . . . . . 40 46 47 49 51 Toxicity of selected heavy metals to marine and estuarine organisms. 56 LIST OF FIGURES Figure Regression analysis for respiratory rate versus.... Of importance in this respect are heavy metals and polychlorinated biphenyls. Style followed 1s that of the Marine biology. Mercury is one of the more important heavy metals. It exists in the environment, when all sources are accounted for...

Green, Felton Allen

2012-06-07

399

Experimental and Molecular study of Cercariae of Clinostomum sp. (Trematoda: Clinostomidae) from Biomphalaria spp. (Mollusca: Planorbidae) in Brazil.  

PubMed

Abstract Despite the large number of reports of species of Clinostomum in vertebrate hosts in South America, studies evaluating the molluscan transmitters of these parasites are scarce. In the present study, clinostomatoid cercariae emerged 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 to 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

Pinto, Hudson Alves; Caffara, Monica; Fioravanti, Maria Letizia; de Melo, Alan L

2014-08-01

400

On growth and form of irregular coiled-shell of a terrestrial snail: Plectostoma concinnum (Fulton, 1901) (Mollusca: Caenogastropoda: Diplommatinidae).  

PubMed

The molluscan shell can be viewed as a petrified representation of the organism's 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-Plectostoma 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's 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

Liew, Thor-Seng; Kok, Annebelle C M; Schilthuizen, Menno; Urdy, Severine

2014-01-01

401

SPATIAL DISTRIBUTION OF LYMNAEIDAE (MOLLUSCA, BASOMMATOPHORA), INTERMEDIATE HOST OF Fasciola hepatica LINNAEUS, 1758 (TREMATODA, DIGENEA) IN BRAZIL  

PubMed Central

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), SpeciesLink (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

Medeiros, Camilla; Scholte, Ronaldo Guilherme Carvalho; D'vila, Sthefane; Caldeira, Roberta Lima; Carvalho, Omar dos Santos

2014-01-01

402

Wheres Waldo? A new commensal species, Waldo arthuri (Mollusca, Bivalvia, Galeommatidae), fromtheNortheastern Pacific Ocean  

PubMed Central

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 arthuris 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

Valentich-Scott, Paul; Foighil, Diarmaid; Li, Jingchun

2013-01-01

403

Long-Term Effects of Ammonia on the Behavioral Activity of the Aquatic Snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca)  

Microsoft Academic Search

An appropriate approach to assess the effect of toxicants on aquatic animals is to monitor behavioral endpoints, as they are\\u000a a link between physiological and ecological processes. A group that can be exposed long-term to low toxic concentrations is\\u000a benthic macroinvertebrates, as their mobility in aquatic ecosystems is relatively limited. Therefore, the study of behavioral\\u000a long-term effects in this group

lvaro Alonso; Julio A. Camargo

2009-01-01

404

Validation of a planimetric procedure to quantify stress in Littorina littorea (Gastropoda: Mollusca): is it independent of the reproductive cycle?  

Microsoft Academic Search

This study forms part of a larger project in which five planimetric parameters have been used to study changes in the digestive\\u000a epithelium of Littorina littorea under different environmental and physiological conditions. Our aim was to examine the effect of the reproductive cycle on\\u000a these parameters in order to assess their usefulness as indicators of stress.\\u000a \\u000a A one way anova

G. Calvo-Ugarteburul; V. Saezl; C. D. McQuaid; E. Angulo

1995-01-01

405

Ecotoxicological studies with newly hatched larvae of Concholepas concholepas (Mollusca, Gastropoda): bioassay with secondary-treated kraft pulp mill effluents.  

PubMed

The Chilean abalone or "loco" (Concholepas concholepas, Bruguire 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

Manrquez, Patricio H; Llanos-Rivera, Alejandra; Galaz, Sylvana; Camao, Andrs

2013-12-01

406

On growth and form of irregular coiled-shell of a terrestrial snail: Plectostoma concinnum (Fulton, 1901) (Mollusca: Caenogastropoda: Diplommatinidae)  

PubMed Central

The molluscan shell can be viewed as a petrified representation of the organisms 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 shellPlectostoma 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 animals 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

Kok, Annebelle C.M.; Schilthuizen, Menno; Urdy, Severine

2014-01-01

407

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 ...

408

Annotated type catalogue of Bothriembryon (Mollusca, Gastropoda, Orthalicoidea) in Australian museums, with a compilation of types in other museums  

PubMed Central

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

Breure, Abraham S.H.; Whisson, Corey S.

2012-01-01

409

LIFE TABLES FOR TWO FIELD POPULATIONS OF SOF'f.SHELL CLAM, MYA ARENARlA, (MOLLUSCA: PELECYPODA)  

E-print Network

) FROM LONG ISLAND SOUND DIANE J. BROUSSEAUl AND JENNY A. BAGLIVO' ABSTRACI' Life tables were constructed for two populations of My/), /),nmaM from Long Island Sound, USA, based on schedules ofage of Long Island Sound. MATERIALS AND METHODS Field Study Areas Field studies were conducted at two

410

Annotated type catalogue of the Megaspiridae, Orthalicidae, and Simpulopsidae (Mollusca, Gastropoda, Orthalicoidea) in the Natural History Museum, London.  

PubMed

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

Breure, Abraham S H; Ablett, Jonathan D

2015-01-01

411

A new genus and species of Thyasiridae (Mollusca, Bivalvia) from deep-water, Beaufort Sea, northern Alaska  

PubMed Central

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

Valentich-Scott, Paul; Powell, Charles L.; II; Lorenson, Thomas D.; Edwards, Brian E.

2014-01-01

412

A natural history of the deep-sea aplacophoran Prochaetoderma yongei and its relationship to confamilials (Mollusca, Prochaetodermatidae)  

NASA Astrophysics Data System (ADS)

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.

Scheltema, Amlie H.; Ivanov, Dmitry L.

2009-09-01

413

Desiccation, higher temperatures and upper intertidal limits of three species of sea mussels (Mollusca: Bivalvia) in New Zealand  

Microsoft Academic Search

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.

V. S. Kennedy

1976-01-01

414

Determination of the optimum concentration of eggs and spermatozoa for the production of normal larvae in Pecten maximus (Mollusca, Lamellibranchia)  

Microsoft Academic Search

Kurzfassung Die KammuschelPecten maximus (L.) erzeugt bei 15 C nahezu whrend des ganzen Jahres reife Keimzellen. Der Reifeproze der Geschlechtszellen kann durch Erniedrigung der Temperatur auf 7 bis 8 C arretiert werden. Der Laichvorgang lt sich dadurch auslsen, indem Kammmuscheln 2 Stunden lang aus dem Wasser entnommen werden. Danach, innerhalb von 2 bis 4 Stunden nach Rckfhrung in Meerwasser, werden

Ll. D. Gruffydd; A. R. Beaumont

1970-01-01

415

Establishment of the green mussel, Perna viridis (Linnaeus 1758) (Mollusca: Mytilidae) on the West Coast of Florida  

USGS Publications Warehouse

In 1999, the green mussel, Perna viridis, was first observed in Tampa Bay, Florida. This was the first reported occurrence of this Indo-Pacific marine bivalve in North America. The mussels found in Tampa Bay were confirmed to be P. viridis based on both morphological and genetic characteristics. Since the initial discovery, surveys in Tampa Bay and on the west coast of Florida have documented the growth, recruitment, and range expansion of P. viridis. From November 1999 to July 2000, the mean shell length of a Tampa Bay population increased from 49.0 mm to 94.1 mm, an increase of 97%. Populations of P. viridis are successfully reproducing in Tampa Bay. Recruitment was observed on sampling plates in May and continued through July 2000. The full extent of mussel colonization is not clear, but mussels were found outside Tampa Bay in St. Petersburg, Florida, south to Venice. Based on these studies it is evident that P. viridis has successfully invaded Tampa Bay and the west coast of Florida. The long-term impact of P. viridis on native communities off the west coast of Florida cannot be predicted at this time.

Benson, A.J.; Marelli, D.C.; Frischer, M.E.; Danforth, J.M.; Williams, J.D.

2001-01-01

416

Evidence for accumulation of Synechococcus elongatus (Cyanobacteria: Cyanophyceae) in the tissues of the oyster Crassostrea gigas (Mollusca: Bivalvia).  

PubMed

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

Avila-Poveda, Omar Hernando; Torres-Ario, Alejandra; Girn-Cruz, Diego Ademir; Cuevas-Aguirre, Angel

2014-10-01

417

Life cycle, population dynamics, growth and production of Abra segmentum (Mollusca, Bivalvia) at low salinities in a Mediterranean lagoon  

NASA Astrophysics Data System (ADS)

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.

Kevrekidis, Theodoros; Kasapis, K.; Kalpia, V.

2009-12-01

418

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...

419

Do the changes in temperature and light affect the functional response of the benthic mud snail Heleobia australis (Mollusca: Gastropoda)?  

PubMed

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: 20C without light; 30C without light and, 30C 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 gC ind-1h-1 at 20C without light, 1.44 gC ind-1h-1 at 30C without light and 0.64 gC ind-1h-1 at 30C 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 20C 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

Magalhes, Thaisa R F; Neves, Raquel A F; Valentin, Jean L; Figueiredo, Gisela M

2014-09-01

420

First record of Cymatium keenae Beu, 1970 (Mollusca: Ranellidae) from Antofagasta Bay, northern Chile, in connection with El Nio events  

NASA Astrophysics Data System (ADS)

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 Galpagos Islands (Ecuador) in the SE Pacific. Previous evidence strongly suggests that the intrusion of this tropical immigrant can be related to warm El Nio episodes. We analyze the key role of the oceanographic characteristics of Antofagasta Bay as potential temporal refuge for this species.

Ashton, Tom; Riascos, Jose M.; Pacheco, Aldo

2008-03-01

421

Population structure, dynamics and production of Hydrobia ulvae (Pennant) (Mollusca: Prosobranchia) along an eutrophication gradient in the Mondego estuary (Portugal)  

Microsoft Academic Search

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

Ana Isabel Lilleb; Miguel ngelo Pardal; Joo Carlos Marques

1999-01-01

422

Developmental toxicity, acute toxicity and mutagenicity testing in freshwater snails Biomphalaria glabrata (Mollusca: Gastropoda) exposed to chromium and water samples.  

PubMed

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

Tallarico, Lenita de Freitas; Borrely, Sueli Ivone; Hamada, Natlia; Grazeffe, Vanessa Siqueira; Ohlweiler, Fernanda Pires; Okazaki, Kayo; Granatelli, Amanda Tosatte; Pereira, Ivana Wuo; Pereira, Carlos Alberto de Bragana; Nakano, Eliana

2014-12-01

423

Differences in absolute and relative growth between two shell forms of Pinna nobilis (Mollusca: Bivalvia) along the Tunisian coastline  

NASA Astrophysics Data System (ADS)

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.

Rabaoui, Lotfi; Tlig-Zouari, Sabiha; Katsanevakis, Stelios; Belgacem, Walid; Hassine, Oum Kalthoum Ben

2011-08-01

424

Development and validation of an OECD reproductive toxicity test guideline with the pond snail Lymnaea stagnalis (Mollusca, Gastropoda).  

PubMed

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 201C, 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

Ducrot, Virginie; Askem, Clare; Azam, Didier; Brettschneider, Denise; Brown, Rebecca; Charles, Sandrine; Coke, Mara; Collinet, Marc; Delignette-Muller, Marie-Laure; Forfait-Dubuc, Carole; Holbech, Henrik; Hutchinson, Thomas; Jach, Arne; Kinnberg, Karin L; Lacoste, Cdric; Le Page, Gareth; Matthiessen, Peter; Oehlmann, Jrg; Rice, Lynsey; Roberts, Edward; Ruppert, Katharina; Davis, Jessica Elphinstone; Veauvy, Clemence; Weltje, Lennart; Wortham, Ruth; Lagadic, Laurent

2014-09-16

425

Integrative study of a new cold-seep mussel (Mollusca: Bivalvia) associated with chemosynthetic symbionts in the Marmara Sea  

NASA Astrophysics Data System (ADS)

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.

Ritt, Bndicte; Duperron, Sbastien; Lorion, Julien; Sara Lazar, Cassandre; Sarrazin, Joze

2012-09-01

426

Absence of formation of benzo[a]pyrene/DNA adducts in the cuttlefish (Sepia officinalis, Mollusca: Cephalopoda)  

SciTech Connect

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.

Lee, P.G.; Lu, L.J.W.; Salazar, J.J.; Holoubek, V. (Univ. of Texas Medical Branch, Galveston, TX (United States))

1994-01-01

427

Mortality of unionid bivalves (Mollusca) associated with Dreissenid mussels (Dreissena polymorpha and D. bugensis) in Presque Isle Bay, Lake Erie  

USGS Publications Warehouse

Two exotic species of dreissenid mussels (Dreissena polymorpha and D. bugensis) began to colonize bottom substrates in Presque Isle Bay, Lake Erie in 1990. By 1991, all native unionid (Unionidae) shells were infested by dreissenids. In 1990 and 1991, about 500 individual unionids of 15 species were collected: in 1992, 246 individuals of 12 species were collected; in 1993, 64 individuals of 6 species; in 1994, three individuals of three species; and in 1995, no unionids were found. In general, infestation indices of unionids were relatively low in 1990 and 1991, increased in 1992, and decreased in 1993. Mortality of unionids associated with infestation in the bay occurred in a shorter period of time (ca. two to three years) than has been documented in other water bodies. Observations in an area of Presque Isle not included in the present study, indicate that a small remnant population of unionids exists in the presence of heavily-colonized substrates by dreissenid mussels. Since other shallow-water areas of Lake Erie support infestation-free unionids in the presence of dreissenid mussels, it is hoped that some unionids will survive in Presque Isle Bay of Lake Erie.

Schloesser, Don W.; Masteller, Edwin C.

1999-01-01

428

Cytogenetic characterisation of the razor shells Ensis directus (Conrad, 1843) and E. minor (Chenu, 1843) (Mollusca: Bivalvia)  

NASA Astrophysics Data System (ADS)

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.

Gonzlez-Tizn, Ana M.; Rojo, Vernica; Vierna, Joaqun; Jensen, K. Thomas; Egea, Emilie; Martnez-Lage, Andrs

2013-03-01

429

Spatial diversity of rocky midlittoral macro-invertebrates associated with the endangered species Patella ferruginea (Mollusca: Gastropoda) of Tunisian coastline  

NASA Astrophysics Data System (ADS)

The present study focuses on horizontal spatial variability of benthic macrofauna associated with Patella ferruginea. Thirty-six samples collected at 12 transects belonging to 4 midlittoral sites along the rocky Tunisian coastline, were examined. A total of 44 species belonging to 5 taxa were found. Multivariate analysis applied on gathered data did not show a horizontal spatial variability at small scale (between transects), but at large scale, between sites as well as sectors. Thus, three groups of communities were identified (GI: Korbous and El Haouaria; GIIa: Zembra Island and GIIb: Kelibia). The distribution of species abundance within these groups revealed that crustaceans were the most abundant taxon, due to the overwhelming dominance of Chthamalus stellatus. This substratum appeared to create favourable micro-habitats for the installation of molluscs including gastropods. Regarding the low diversity index ( H') and evenness ( J), they seemed to reflect a disturbance and a demographic unbalance within these communities. The heterogeneity of substrate surface, created by C. stellatus specimens appeared to be caused by various complex interactions established between the key components of these communities in particular suspension feeders, predators, herbivorous molluscs and macroalgae. Thus, the dynamic status of each of these communities is the result of these complex interactions.

Tlig-Zouari, Sabiha; Rabaoui, Lotfi; Fguiri, Hosni; Diawara, Moctar; Ben Hassine, Oum Kalthoum

2010-04-01

430

Opisthobranchia (Mollusca, Gastropoda) more than just slimy slugs. Shell reduction and its implications on defence and foraging  

PubMed Central

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

Wgele, Heike; Klussmann-Kolb, Annette

2005-01-01

431

First molecular phylogeny of the circumtropical bivalve family Pinnidae (Mollusca, Bivalvia): evidence for high levels of cryptic species diversity.  

PubMed

The family Pinnidae Leach, 1819, includes approximately 50 species of large subtidal and coastal marine bivalves. These commercially important species occur in tropical and temperate waters around the world and are most frequently found in seagrass meadows. The taxonomy of the family has been revised a number of times since the early 20th Century, the most recent revision recognizing 55 species distributed in three genera: Pinna, Atrina and Streptopinna, the latter being monotypic. However, to date no phylogenetic analysis of the family has been conducted using morphological or molecular data. The present study analyzed 306 pinnid specimens from around the world, comprising the three described genera and ca. 25 morphospecies. We sequenced the mitochondrial genes 16S rRNA and cytochrome c oxidase subunit I, and the nuclear ribosomal genes 18S rRNA and 28S rRNA. Phylogenetic analysis of the data revealed monophyly of the genus Atrina but also that the genus Streptopinna is nested within Pinna. Based on the strong support for this relationship we propose a new status for Streptopinna Martens, 1880 and treat it as a subgenus (status nov.) of Pinna Linnaeus, 1758. The phylogeny and the species delimitation analyses suggest the presence of cryptic species in many morphospecies displaying a wide Indo-Pacific distribution, including Pinna muricata, Atrina assimilis, A. exusta and P. (Streptopinna) saccata but also in the Atlantic species A. rigida. Altogether our results highlight the challenges associated with morphological identifications in Pinnidae due to the presence of both phenotypic plasticity and morphological stasis and reveal that many pinnid species are not as widely distributed as previously thought. PMID:24569016

Lemer, Sarah; Buge, Barbara; Bemis, Amanda; Giribet, Gonzalo

2014-06-01

432

A new species of Pulvinites (Mollusca: Bivalvia) from the upper Paleocene Paspotansa Member of the Aquia Formation in Virginia ( USA).  

USGS Publications Warehouse

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

Ward, L.W.; Waller, T.R.

1988-01-01

433

Subterranean Biodiversity of Arkansas, Part 2: Status Update of the Foushee Cavesnail, Amnicolacora Hubricht, 1979 (Mollusca: Gastropoda: Hydrobiidae)  

Microsoft Academic Search

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

G. O. Graening

2003-01-01

434

[Evolutionary history of Metazoa, ancestral status of the bilateria clonal reproduction, and semicolonial origin of the mollusca].  

PubMed

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

Martynov, A V

2013-01-01

435

Antimicrobial activities of the tissue extracts of Babylonia spirata Linnaeus, 1758 (Mollusca: Gastropoda) from Thazhanguda, southeast coast of India  

PubMed Central

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

Periyasamy, N; Srinivasan, M; Balakrishnan, S

2012-01-01

436

Identification of protein components of egg masses indicates parental investment in immunoprotection of offspring by Biomphalaria glabrata (Gastropoda, Mollusca)  

PubMed Central

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 unknown 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

Hathaway, Jennifer J M; Adema, Coen M.; Stout, Barbara A.; Mobarak, Charlotte D; Loker, Eric S

2009-01-01

437

Isolation and characterization of the first microsatellite markers for the endangered relict mussel Hypanis colorata (Mollusca: Bivalvia: Cardiidae).  

PubMed

Hypanis colorata (Eichwald, 1829) (Cardiidae: Lymnocardiinae) is a bivalve relict species with a Ponto-Caspian distribution and is under strict protection in Romania, according to national regulations. While the species is depressed in the western Black Sea lagoons from Romania and Ukraine, it is also a successful invader in the middle Dniepr and Volga regions. Establishing a conservation strategy for this species or studying its invasion process requires knowledge about the genetic structure of the species populations. We have isolated and characterized nine polymorphic microsatellite markers in H. colorata. The number of alleles per locus ranged from 4 to 28 and the observed heterozygosity ranged from 0.613 to 1.000. The microsatellites developed in the present study are highly polymorphic and they should be useful for the assessment of genetic variation within this species. PMID:21339997

Popa, Oana Paula; Iorgu, Elena Iulia; Krapal, Ana Maria; Kelemen, Beatrice Simona; Murariu, Dumitru; Popa, Luis Ovidiu

2011-01-01

438

Growth estimation of mangrove cockle Anadara tuberculosa (Mollusca: Bivalvia): application and evaluation of length-based methods.  

PubMed

Growth is one of the key processes in the dynamic of exploited resources, since it provides part of the information required for structured population models. Growth of mangrove cockle, Anadara tuberculosa was estimated through length-based methods (ELEFAN I y NSLCA) and using diverse shell length intervals (SLI). The variability of L(infinity), k and phi prime (phi') estimates and the effect of each sample were quantified by jackknife techniques. Results showed the same L(infinity) estimates from ELEFAN I and NSLCA across each SLI used, and all L(infinity) were within the expected range. On the contrary, k estimates differed between methods. Jackknife estimations uncovered the tendency of ELEFAN I to overestimate k with increases in SLI, and allowed the identification of differences in uncertainty (PE and CV) between both methods. The average values of phi' derived from NSCLA1.5 and length-age sources were similar and corresponded to ranges reported by other authors. Estimates of L(infinity), k and (phi' from NSCLA1.5 were 85.97 mm, 0.124/year and 2.953 with jackknife and 86.36mm de L(infinity), 0.110/year de k and 2.914 de phi' without jackknife, respectively. Based on the observed evidence and according to the biology of the species, NSCLA is suggested to be used with jackknife and a SLI of 1.5 mm as an ad hoc approach to estimate the growth parameters of mangrove cockle. PMID:21513195

Flores, Luis A

2011-03-01

439

Distribution, biomass, recruitment and productivity of Anadara senilis (L.) (Mollusca: Bivalvia) on the banc d'Arguin, Mauritania  

NASA Astrophysics Data System (ADS)

Data on distribution, ecology, biomass, recruitment, growth, mortality and productivity of the West African bloody cockle Anadara senilis were collected at the Banc d'Aguuin, Mauritania, in early 1985 and 1986. Ash-free dry weight appeared to be correlated best with shell height. A. senilis was abundant on the tidal flats of landlocked coastal bays, but nearly absent on the tidal flats bordering the open sea. The average biomass for the entire area of tidal flats was estimated at 5.5 gm -2 ash-free dry weight. The A. senilis population appeared to consist mainly of 10 to 20-year-old individuals, showing a very slow growth and a production: biomass ratio of about 0.02 y -1. Recruitment appeared negligible and mortality was estimated to be about 10% per year. Oystercatchers ( Haematopus ostralegus), the gastropod Cymbium cymbium and unknown fish species were responsible for a large share of this. The distinction of annual growth marks permitted the assessment of year-class strength, which appeared to be correlated with the average discharge of the river Senegal. This may be explained by assuming that year-class strength and river discharge both are correlated with rainfall at the Banc d'Arguin.

Wolff, W. J.; Gueye, Abou; Meijboom, A.; Piersma, Th.; Alassane Sall, Mamadou

440

Assimilation of terrigenous organic matter via bacterial biomass as a food source for a brackish clam, Corbicula japonica (Mollusca: Bivalva)  

NASA Astrophysics Data System (ADS)

Corbicula japonica collected from the Kitakami River estuary, northeastern Japan, showed lower ?34S values in soft-body parts (+1.7 to +11.0) than the ambient seawater sulfate sulfur (+21), and this value gradually decreased at successive sites up to 15.8 km upstream from the river mouth. Previous study using carbon and nitrogen isotopes suggests that the bivalve nonselectively assimilates particulate organic matter of marine and terrestrial origin by filter feeding. This pattern in ?34S values may indicate a considerable contribution of a food source derived from terrigenous organic matter, which has low ?34S values close to 0, and the bivalve has been reported to have cellulase and hemicellulase activities. Unique fatty acids (iso 17:0 and anteiso 17:0 acids), both characteristic of sulfate-reducing bacteria, were observed in the salt-free, soft-body parts of the bivalve. The concentration of monounsaturated fatty acids, possibly derived from bacteria, was also high. Trace amounts of a polyunsaturated fatty acid (20:5?3) specific to dinoflagellates were detected. In Corbicula habitats, reductive sandy layers with ample sulfides that were sporadically intercalated into the oxidative sandy sediment were often observed. The stable isotopic signatures of sediment sulfides (acid-volatile sulfide) and associated pore-water sulfates were -8.9 to +8.6 and +22.4 to +26.3, respectively, indicating the existence of bacterial sulfate-reducing activity and thiobios biomass. These isotopic signatures of the sediment, with the fatty acid composition of the bivalve, confirm the importance of a food source derived from bacteria belonging to the thiobios in the substrate sediments via pedal feeding, rather than direct digestion of terrigenous organic matter, in this estuarine ecosystem.

Yamanaka, Toshiro; Mizota, Chitoshi; Maki, Yonosuke; Matsumasa, Masatoshi

2013-07-01

441

Characterization of nineteen microsatellite markers and development of multiplex PCRs for the wedge clam Donax trunculus (Mollusca: Bivalvia).  

PubMed

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

Nantn, Ana; Arias-Prez, Alberto; Mndez, Josefina; Freire, Ruth

2014-08-01

442

Polyplacophora (Mollusca) from the San Diego Formation: A remarkable assemblage of fossil chitons from the Pliocene of southern Califoria  

USGS Publications Warehouse

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.

Vendrasco, Michael J.; Eernisse, Douglas J.; Powell, Charles L.; Fernandez, Christine Z.

2012-01-01

443

Dopaminergic neurons in the brain and dopaminergic innervation of the albumen gland in mated and virgin helisoma duryi (mollusca: pulmonata)  

PubMed Central

Background Dopamine was shown to stimulate the perivitelline fluid secretion by the albumen gland. Even though the albumen gland has been shown to contain catecholaminergic fibers and its innervation has been studied, the type of catecholamines, distribution of fibers and the precise source of this neural innervation has not yet been deduced. This study was designed to address these issues and examine the correlation between dopamine concentration and the sexual status of snails. Results Dopaminergic neurons were found in all ganglia except the pleural and right parietal, and their axons in all ganglia and major nerves of the brain. In the albumen gland dopaminergic axons formed a nerve tract in the central region, and a uniform net in other areas. Neuronal cell bodies were present in the vicinity of the axons. Dopamine was a major catecholamine in the brain and the albumen gland. No significant difference in dopamine quantity was found when the brain and the albumen gland of randomly mating, virgin and first time mated snails were compared. Conclusions Our results represent the first detailed studies regarding the catecholamine innervation and quantitation of neurotransmitters in the albumen gland. In this study we localized catecholaminergic neurons and axons in the albumen gland and the brain, identified these neurons and axons as dopaminergic, reported monoamines present in the albumen gland and the brain, and compared the dopamine content in the brain and the albumen gland of randomly mating, virgin and first time mated snails. PMID:11513757

Kiehn, Lana; Saleuddin, Saber; Lange, Angela

2001-01-01

444

Alterations in the mantle epithelium during transition from hatching gland to adhesive organ of Idiosepius pygmaeus (Mollusca, Cephalopoda).  

PubMed

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

Cyran, Norbert; Klepal, Waltraud; Stdler, Yannick; Schnenberger, Jrg; von Byern, Janek

2015-02-01

445

Evolutionary Dynamics of rDNA Clusters in Chromosomes of Five Clam Species Belonging to the Family Veneridae (Mollusca, Bivalvia)  

PubMed Central

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

Prez-Garca, Concepcin; Hurtado, Ninoska S.; Morn, Paloma; Pasantes, Juan J.

2014-01-01

446

Ultrastructure of the mature spermatozoon of the bivalve Estellarca olivacea (Mollusca: Bivalvia: Arcidae) and its phylogenetic implications.  

PubMed

Ultrastructure of mature spermatozoa of Estellarca olivacea was studied by transmission electron microscopy and its phylogenetic implications are discussed for the first time in this paper. The mature spermatozoon is composed of a head which contains a cone-shaped acrosome, a round nucleus and a tail region. The subacrosomal space is less electron dense which contains a homogeneous material. No axial rod and a basal plate were observed in subacrosomal space. No anterior invagination exists in the nucleus, but an inverted shallow V-shaped posterior invagination is visible. Nuclear lacunae could be seen clearly although the nucleus is highly condensed. Within the mid-piece of the spermatozoon there exist five spherical mitochondria while the long whip-like end portion is composed of an axoneme with the typical 9+2 structure. The spermatozoon of Estellarca olivacea is a product of the evolution of the reproductive system of the family Arcidae. Whether the particular acrosome, subacrosomal space, or the highly condensed nucleus might be adaptations of high fertilization rate in the particular environment of this species is discussed. PMID:19378921

Zhu, Jun-Quan; Yang, Wan-Xi

2009-03-01

447

New insight in lymnaeid snails (Mollusca, Gastropoda) as intermediate hosts of Fasciola hepatica (Trematoda, Digenea) in Belgium and Luxembourg  

PubMed Central

Background The present study aims to assess the epidemiological role of different lymnaeid snails as intermediate hosts of the liver fluke Fasciola hepatica in Belgium and Luxembourg. Methods During summer 2008, 7103 lymnaeid snails were collected from 125 ponds distributed in 5 clusters each including 25 ponds. Each cluster was located in a different biogeographic area of Belgium and Luxembourg. In addition, snails were also collected in sixteen other biotopes considered as temporary wet areas. These snails were identified as Galba truncatula (n?=?2474) (the main intermediate host of F. hepatica in Europe) and Radix sp. (n?=?4629). Moreover, several biological and non-biological variables were also recorded from the different biotopes. DNA was extracted from each snail collected using Chelex technique. DNA samples were screened through a multiplex PCR that amplifies lymnaeid internal transcribed spacer 2 gene sequences (500600bp) (acting as an internal control) and a 124bp fragment of repetitive DNA from Fasciola sp. Results Lymnaeid snails were found in 75 biotopes (53.2%). Thirty individuals of G. truncatula (1.31%) and 7 of Radix sp. (0.16%) were found to be positive for Fasciola sp. The seven positive Radix sp. snails all belonged to the species R. balthica (Linnaeus, 1758). Classification and regression tree analysis were performed in order to better understand links and relative importance of the different recorded factors. One of the best explanatory variables for the presence/absence of the different snail species seems to be the geographic location, whereas for the infection status of the snails no obvious relationship was linked to the presence of cattle. Conclusions Epidemiological implications of these findings and particularly the role of R. balthica as an alternative intermediate host in Belgium and Luxembourg were discussed. PMID:24524623

2014-01-01

448

Annotated type catalogue of the Megaspiridae, Orthalicidae, and Simpulopsidae (Mollusca, Gastropoda, Orthalicoidea) in the Natural History Museum, London  

PubMed Central

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 dOrbigny, 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 (dOrbigny, 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

Breure, Abraham S. H.; Ablett, Jonathan D.

2015-01-01

449

A new genus and species of Thyasiridae (Mollusca, Bivalvia) from deep-water, Beaufort Sea, northern Alaska.  

PubMed

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

Valentich-Scott, Paul; Powell, Charles L; Ii; Lorenson, Thomas D; Edwards, Brian E

2014-01-01

450

[A metacercarial disease in the dogfish species Umbra limi (Teleostei) and a trematode infestation in a Physa sp. (Mollusca)].  

PubMed

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

Foersch, W; Reichenbach-Klinke, H H; Schaller, D; Schmidt, K

1984-01-01

451

Complete female mitochondrial genome of Anodonta anatina (Mollusca: Unionidae): confirmation of a novel protein-coding gene (F ORF).  

PubMed

Abstract Freshwater mussels are among animals having two different, gender-specific mitochondrial genomes. We sequenced complete female mitochondrial genomes from five individuals of Anodonta anatina, a bivalve species common in palearctic ecozone. The length of the genome was variable: 15,637-15,653?bp. This variation was almost entirely confined to the non-coding parts, which constituted approximately 5% of the genome. Nucleotide diversity was moderate, at 0.3%. Nucleotide composition was typically biased towards AT (66.0%). All genes normally seen in animal mtDNA were identified, as well as the ORF characteristic for unionid mitochondrial genomes, bringing the total number of genes present to 38. If this additional ORF does encode a protein, it must evolve under a very relaxed selection since all substitutions within this gene were non-synonymous. The gene order and structure of the genome were identical to those of all female mitochondrial genomes described in unionid bivalves except the Gonideini. PMID:24020999

Soroka, Marianna; Burzy?ski, Artur

2013-09-11

452

A cybertaxonomic revision of the micro-landsnail genus Plectostoma Adam (Mollusca, Caenogastropoda, Diplommatinidae), from Peninsular Malaysia, Sumatra and Indochina  

PubMed Central

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

Liew, Thor-Seng; Vermeulen, Jaap Jan; Marzuki, Mohammad Effendi bin; Schilthuizen, Menno

2014-01-01

453

Opisthobranchia (Mollusca, Gastropoda) - more than just slimy slugs. Shell reduction and its implications on defence and foraging.  

PubMed

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

Wgele, Heike; Klussmann-Kolb, Annette

2005-02-16

454

Opisthobranchia (Mollusca, Gastropoda) more than just slimy slugs. Shell reduction and its implications on defence and foraging  

Microsoft Academic Search

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,

Heike Wgele; Annette Klussmann-Kolb

2005-01-01

455

Growth of Argopecten purpuratus (Mollusca: Bivalvia) on a natural bank in Northern Chile: sclerochronological record and environmental controls  

Microsoft Academic Search

Daily striae on the shell of the scallop, Argopecten purpuratus, were used to investigate its growth in a protected population within La Rinconada Bay, near Antofagasta (2nd Region, Northern Chile), and to determine how environmental forcings control shell growth. This sclerochronological approach was useful to describe daily shell growth a posteriori. Mean shell growth rates were calculated daily between February

Julien Thbault; Grard Thouzeau; Laurent Chauvaud; Marcela Cantillnez; Miguel Avendao

2008-01-01

456

Diel variation of the RNA/DNA ratios in Crassostrea angulata (Lamarck) and Ruditapes decussatus (Linnaeus 1758) (Mollusca: Bivalvia).  

PubMed

The aim of this study was to investigate the effect of time of day on RNA/DNA ratios among fed and starved Crassostrea angulata and Ruditapes decussatus juveniles. Sampling to investigate the day and night condition of juveniles was carried out for 48 h. A highly sensitive method for nucleic acid quantification was applied to bivalves. The results suggest that there is some variation in nucleic acid quantities with the time of the day. For the two species analysed, the RNA/DNA ratio was particularly high during the night and was higher in the fed animals. The results seem to indicate that there is some endogenous rhythm in the production of RNA. If there are diel changes in RNA/DNA ratios, it follows that average RNA/DNA ratios can be unrepresentative if there is any day or night bias in sampling. PMID:11325380

Chcharo, L M.Z.; Chcharo, M A.; Alves, F; Amaral, A; Pereira, A; Regala, J

2001-04-30

457

Effects of food type, feeding frequency, and temperature on juvenile survival and growth of Marisa cornuarietis (Mollusca: Gastropoda)  

PubMed Central

The present experiments are part of a larger study designed to investigate the influence of husbandry parameters on the life history of the ramshorn snail, Marisa cornuarietis, in order to identify suitable husbandry conditions for maintaining multi-generation populations in the laboratory for use in ecotoxicological testing. In this paper we focus on the effects of a combination of food types and feeding frequencies (i.e., the frequency with which the snails were offered food) on juvenile growth and survival at different temperatures. Offspring produced in the laboratory by wild specimens of M. cornuarietis, from Puerto Rico, were used to test the effects of three types of food (lettuce, alginate with fish food, alginate with snail mix) fed at three frequencies (given ad libitum on 4/4, 2/4, or 1/4 d) on juvenile survival and growth. The 4-d feeding regimens were repeated four times, giving a total of 16 d for the experiments. The experiments were conducted at two temperatures (22 and 25C) under a 12 h light:12 h dark photoperiod. Juvenile growth rates increased with increasing feeding frequency for all food types. The most rapid growth rates occurred in the high-frequency lettuce treatments and the slowest growth rates in the low-frequency lettuce and alginate with snail mix treatments. Juvenile snails grew faster at 25 than at 22C, and mortality was about twice as high at the lower temperature. Growth rates were used to provide a rough estimate of time to maturity, which was determined to take about twice as long at 22 than at 25C. The results showed that lettuce is the best food if supplied in abundance, but effects on growth are very dependent on feeding frequency and temperature. We conclude that 25C is a more appropriate temperature for maintaining populations than 22C, that lettuce provides a suitable food source, and that food should be supplied continuously for husbandry and toxicity testing of populations of M. cornuarietis. PMID:19009044

Selck, Henriette; Aufderheide, John; Pounds, Nadine; Staples, Charles; Caspers, Norbert; Forbes, Valery

2006-01-01

458

A cybertaxonomic revision of the micro-landsnail genus Plectostoma Adam (Mollusca, Caenogastropoda, Diplommatinidae), from Peninsular Malaysia, Sumatra and Indochina.  

PubMed

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

Liew, Thor-Seng; Vermeulen, Jaap Jan; Marzuki, Mohammad Effendi Bin; Schilthuizen, Menno

2014-01-01

459

A novel structural class of toxins: the methionine-rich peptides from the venoms of turrid marine snails (Mollusca, Conoidea).  

PubMed

The objective of this investigation was to purify and characterize polypeptides from the venom ducts of the turrid snails Polystira albida and Gemmula periscelida (superfamily: Conoidea, family: Turridae), collected in Mexican waters. Venoms of other groups in the superfamily (family: Conidae, genus: Conus) have peptide toxins ('conotoxins'), but no venom components have been characterized from any turrid species. Crude venoms were fractionated using reversed-phase high performance liquid chromatography, and one major component from each venom was characterized. In contrast to most conotoxins, the polypeptides characterized contain a high proportion of Met, Tyr and Arg residues, and few, if any, Cys residues. The two peptides had some regions of homology, but were not significantly similar to other peptides. Both peptides are predicted to contain alpha-helical structures, and the peptide from P. albida is predicted to form a coiled-coil motif. This structural motif could provide conformational stability for these turrid venom components ("turritoxins"), which in the case of conotoxins is primarily achieved by disulfide bonds. Thus, the first turritoxins characterized are strikingly different from the conotoxins, suggesting divergent biochemical strategies in the venoms of different major groups included in the superfamily Conoidea. PMID:15051399

Lpez-Vera, Estuardo; Heimer de la Cotera, Edgar P; Maillo, Mara; Riesgo-Escovar, Juan R; Olivera, Baldomero M; Aguilar, Manuel B

2004-03-15

460

Marine Mollusca of isotope stages of the last 2 million years in New Zealand. Part 4. Gastropoda (Ptenoglossa, Neogastropoda, Heterobranchia)  

Microsoft Academic Search

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 Insolentia solitaria King, bathyal Nukumaruan, Palliser Bay. Xymene (sensu stricto; separated again from Axymene, Xymenella and Zeatrophon) is

AG Beu

2011-01-01

461

A novel structural class of toxins: the methionine-rich peptides from the venoms of turrid marine snails (Mollusca, Conoidea)  

Microsoft Academic Search

The objective of this investigation was to purify and characterize polypeptides from the venom ducts of the turrid snails Polystira albida and Gemmula periscelida (superfamily: Conoidea, family: Turridae), collected in Mexican waters. Venoms of other groups in the superfamily (family: Conidae, genus: Conus) have peptide toxins (conotoxins), but no venom components have been characterized from any turrid species. Crude venoms

Estuardo Lpez-Vera; Edgar P Heimer de la Cotera; Mar??a Maillo; Juan R Riesgo-Escovar; Baldomero M Olivera; Manuel B Aguilar

2004-01-01

462

The genetic dynamics of the rapid and recent colonization of Denmark by Arion lusitanicus (Mollusca, Pulmonata, Arionidae).  

PubMed

We describe the genetic dynamics of the recent establishment of the 'Iberian slug', Arion lusitanicus J. Mabille 1868, in Denmark and compare its population structure to two other members of the 'large 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 that: (1) None of the three taxa reproduce primarily by self-fertilization. Differences among loci and colonies in the pattern of deviation from Hardy-Weinberg equilibrium are most consistent with isolate mixing and perhaps with low amounts of selfing. (2) For both A. lusitanicus and A. a. rufus, gene diversity is lower in Danish colonies than in southern German colonies, implying population bottlenecks in the establishment of Danish colonies. (3) Significant linkage disequilibrium values usually involve the same three loci, viz. PGI, MDH-1 and MDH-2, suggesting physical linkage among these loci. (4) For both A. a. rufus and A. lusitanicus, the overall gene frequencies from Denmark and southern Germany are homogeneous, while variation among colonies within these regions ranges from around 15 to 28% for the three taxa. This indicates strong, local population genetic subdivision but with little restriction to gene flow from possible source areas. The heterogeneity in measures of diversity and differentiation indicates that population structure for all three taxa is dominated by ongoing founder effects, local extinction/colonisation dynamics, and genetic drift processes. PMID:21523466

Engelke, S; Kmpf, J; Jordaens, K; Tomiuk, J; Parker, E D

2011-06-01

463

A new species of small-eared shrew, genus Cryptotis (Insectivora: Soricidae), from Honduras.  

E-print Network

We describe a new species of small-eared shrew, Cryptotis hondurensis (Insectivora: Soricidae), from high elevation pine forest on the western slope of Cerro Uyuca, Francisco Morazn Province, southcentral Honduras. The new shrew is most similar...Resumen.--Se describe una nueva especie de musaraa, Cryptotis hondurensis (Insectivora: Soricidae), del bosque montanoso de la ladera occidental del Cerro Uyuca, Francisco Morazn, Honduras. Externamente, la nueva especie es similar a C. gracilis pero se diferencia de C. gracilis en caractersticas craniales y dentales; en particular, en la presencia de una mandbula mas corta y mas ancha y con un proceso coronoides que se junta con la rama mandibular en un ngulo de casi 90 grados. Adems, m3 presenta una talonida simple. El crneo de la nueva musaraa se semejante al de C. nigrescens merriami pero la nueve especie defiere de C. nigrescens merriami por su cola mas larga y en varias caractersticas craniales y dentales incluyendo M3 con una corona mas compleja. El holotipo de la nueva especie haba sido identificado como C. gracilis y este especimen era el nico representante de esta especie al norte de Costa Rica. El reconocimiento de este especimen como una especie distinta, limita la distribucin de C. gracilis a Costa Rica y Panam y la remueve de la fauna de Honduras. Las otras especies de Cryptotis que habitan en Honduras son C. nigrescens merriami y C. parva orophila....

Woodman, Neal; Timm, Robert M.

1992-03-01

464

INVERTEBRADOS 2014 Cronograma de Atividades -Diurno  

E-print Network

08 de abril 14:00 2ª AVALIA??O: Assunto da prova: de Mollusca até Lophophorata 20 de maio 14:00 3ª Platyhelminthes II 12 quarta Teórica Mollusca I 18 terça PROVA 1ª AVALIA??O (conteúdo até Platyheminthes) 19 quarta Teórica e Prática Mollusca II 25 terça Teórica e Prática Mollusca III 26 quarta Teórica e Prática

Morandini, Andre C.

465

INVERTEBRADOS 2014 Cronograma de Atividades -Noturno  

E-print Network

Platyheminthes 08 de abril 19:00 2ª AVALIA??O: Assunto da prova: de Mollusca até Lophophorata 20 de maio 19:00 3ª Platyhelminthes II 12 quarta Teórica Mollusca I 18 terça PROVA 1ª AVALIA??O (conteúdo até Platyheminthes) 19 quarta Teórica e Prática Mollusca II 25 terça Teórica e Prática Mollusca III 26 quarta Teórica e Prática

Morandini, Andre C.

466

Mar Biol (2007) 151:12151223 DOI 10.1007/s00227-006-0563-2  

E-print Network

belong to members of various phyla including Porifera, Cnidaria, Platyhelminthes, and Mollusca (Douglas to the well-studied cnidarians, symbiotic platyhelminth worms, and particularly acoelomorphs are the most

467

Actine,Apicomplexes, Bourgeonnement, Cil, Cilis, Complexe apical, Conjugaison, Cycle biologique de Plasmodium, Cytosquelette, Cytostome, Diffusion, Ectoplasme,  

E-print Network

Sarcomastigophora Ciliophora Arthropoda Mollusca Chordata Playhelminthes Nematoda Annelida Porifera Echinodermata Nematomorpha Nematoda Priapulida Kinorhyncha Loricifera Echinodermata Hemichordata Chordata ?vidence

Blouin-Demers, Gabriel

468

Su Nueva Vida en los Estados Unidos. (Your New Life in the United States).  

ERIC Educational Resources Information Center

An illustrated guide to aspects of life in the United States is presented in Spanish for recent Hispanic arrivals. The guidelines address such topics as resettlement agencies, community relations and national customs, the U.S. government, local and long distance transport, mail and telephone communication systems, employment practices, the

Escobar, Vivian; And Others

469

Darryl E. Jory Centro de Investigaciones Cientl'ficas. Universidad de Oriente. NLlcleo de Nueva Esparta  

E-print Network

Related to Burying Behavior in Queen Conch Strombus gigas Interest in queen conch Strombus ui1Jas. Information on survival, including predation rates during the period after larval conch have left, very few small conch « 1 year- old; "'5 em in length) have been found in nature (Robertson 1959

470

El Renacimiento de la Sociologa Consecuencias epistemolgicas de las metodologas informticas para una nueva sociologa contempornea  

Microsoft Academic Search

The potential of the computer methodologies for the sociology becomes more and more evident, as well as it is more and more evident that the same sociology is more and more immerse in a society of the knowledge whose main fuel is the information and its reflexive structuring and communicative. The investigation methodologies and production of sociological knowledge linked to

Gilson Lima

471

ANLISIS DE INCIDENCIA DEL GASTO PBLICO EN EDUCACIN SUPERIOR: NUEVAS APROXIMACIONES  

Microsoft Academic Search

Los estudios de incidencia del gasto se han contrastado de forma emprica fundamentalmente a travs de la metodologa de incidencia normativa del gasto, tcnica que cuenta con importantes limitaciones, algunas de ellas insalvables. Intentando ofrecer nuevos enfoques, existen lneas de investigacin que tratan de incluir comportamiento, y derivadas de stas, otras aproximaciones que intentan estudiar conjuntamente comportamiento e incidencia, aunque

Mara Gil Izquierdo

472

NUEVAS CITAS PARA LA FLORA ARGENTINA: COLLOMIA GRANDIFLORA (POLEMONIACEAE) Y POTENTILLA RECTA (ROSACEAE)  

Microsoft Academic Search

Puntieri, J. G. & Brion, C. A. M. 2005. New records for the Argentinian flora: Collomia grandiflora (Polemoniaceae) and Potentilla recta (Rosaceae). Hickenia 3(54): 227-232. The present study reports for the first time the presence of the North American annual herb Collomia grandiflora and the European perennial herb Potentilla recta in northern Patagonia. A population of Collomia grandiflora was found

JAVIER G. PUNTIERI; CECILIA A. M. BRION; CIENTFICAS Y TCNICAS

2005-01-01

473

Nuevas tecnologas e innovaciones en la educacin superior y el desarrollo regional  

Microsoft Academic Search

Segn la Academia de Finlandia y Tekes, la agencia finlandesa de financiacin de tecnologa e innovacin, existen dos fuerzas motrices que destacan dentro del entorno operativo global actual: la primera es la tendencia a una movilidad cada vez mayor y la segunda, la progresiva interdependencia de las diferentes partes del mundo, su paulatina interaccin y colaboracin en la economa, produccin,

Tapio Varis

2007-01-01

474

Nuevas fuentes de energa para un futuro sostenible. Petrleo caro o proteccin del medio?  

Microsoft Academic Search

Los medios de comunicacin no cesan de advertir sobre el creciente grado de emisiones de CO2 a la atmsfera y su responsabilidad directa en la creacin del efecto invernadero, que puede amenazar en un futuro no muy lejano la civilizacin actual. Tambin se sabe que no est garantizado que la extraccin de energas fsiles carbn, petrleo y gas- pueda continuar

Mercedes Arroyo Huguet

2008-01-01

475

EL TURISMO COMO NUEVA FUENTE DE INGRESOS PARA EL MEDIO RURAL DE CASTILLA Y LEN  

Microsoft Academic Search

The Autonomous Community of Castilla y Len represents one of the Spanish regions that more is investing in rural tourism as an economic activity that supplements or subs- titutes to the traditional agricultural activities in rural areas. The outstanding growth that experiences this activity of services in the last years, has been favored by the expansion of the demand of

Margarita Rico Gonzlez

476

Nuevas formas literarias para las ciencias sociales: el caso de la autoetnografa  

Microsoft Academic Search

Este es un trabajo sobre el momento de escribir en el proceso de la investigacin. Es decir sobre el poder de la escritura. La posmodernidad no ha pasado en vano por la psicologa social, ni por el resto de ciencias sociales. Ha aportado un debate crucial sobre las formas de expresin de la ciencia establecida y los efectos de poder

Joel Feliu i Samuel-Lajeunesse

2007-01-01

477

Movilidad de ingreso y trampas de pobreza : nueva evidencia para los pases del Cono Sur  

Microsoft Academic Search

This paper tests the existence of poverty traps in three Southern Cone countries: Argentina, Brazil and Uruguay. We apply the methodology developed by Antman and McKenzie (2005): based on pseudopanels, we model the income dynamics of households and analyze the existence of heterogeneity in their path and their reactions to recessions. We also focus in income trajectories for different educational

Rodrigo Arim; Matas Brum; Andrs Dean; Martn Leites; Gonzalo Salas

2010-01-01

478

LA NUEVA COMUNICACIN VIAJERA: BLOGS Y TURISMO 2.0 EN ESPAA  

E-print Network

fotografía de viajes y expertos en redes sociales y el marketing digital de nuestro país ofrecerán su la aparición y gran popularización en los últimos años de los blogs de viajes y los medios sociale