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Sample records for group anura leptodactylidae

  1. Cuidado parental em Leptodactylus natalensis (Amphibia, Anura, Leptodactylidae Parental care behaviour in Leptodactylus natalensis (Amphibia, Anura, Leptodactylidae

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    Ednilza Maranhão dos Santos

    Full Text Available O presente trabalho registra mais uma espécie pertencente à família Leptodactylidae apresentando cuidado parental, Leptodactylus natalensis Lutz, 1930. Fêmeas foram observadas em assistência a ovos e cardumes de girinos em duas poças temporárias na mata Atlântica do Estado de Pernambuco, Brasil.The present paper reports one more species of the family Leptodactylidae presenting parental care behaviour, Leptodactylus natalensis Lutz, 1930, in which females were observed attending eggs and schools of tadpoles in two temporary ponds in the Atlantic forest of the State of Pernambuco, Brazil.

  2. Environmental, land cover and land use constraints on the distributional patterns of anurans: Leptodacylus species (Anura, Leptodactylidae) from Dry Chaco.

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    Medina, Regina Gabriela; Ponssa, Maria Laura; Aráoz, Ezequiel

    2016-01-01

    Subtropical dry forests are among the most vulnerable biomes to land transformation at a global scale. Among them, the Dry Chaco suffers an accelerated change due to agriculture expansion and intensification. The Dry Chaco ecoregion is characterized by high levels of endemisms and species diversity, which are the result of a variety of climates and reliefs, allowing a wide variety of environments. The amphibian group exhibits a high richness in the Dry Chaco, which has been barely studied in relation to land cover changes. We used ecological niche models (ENMs) to assess the potential geographic distribution of 10 Leptodactylus species (Anura, Leptodactylidae), which are mainly distributed within the Dry Chaco. We characterized these distributions environmentally, analyzed their overlap with land cover classes, and assessed their diversity of ecoregions. Also, we evaluated how these species potential distribution is affected by the transformation of land, and quantified the proportional area of the potential distribution in protected areas. We found that temperature seasonality is the main constraint to the occurrence of the species studied, whose main habitats are savannas, grasslands and croplands. The main threats to these species are the effects of climate change over spatial patterns of seasonality, which could affect their breeding and reproduction mode; the loss of their natural habitat; the exposure to contaminants used by intensive agriculture and their underrepresentation in protected areas.

  3. Environmental, land cover and land use constraints on the distributional patterns of anurans: Leptodacylus species (Anura, Leptodactylidae from Dry Chaco

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    Regina Gabriela Medina

    2016-11-01

    Full Text Available Subtropical dry forests are among the most vulnerable biomes to land transformation at a global scale. Among them, the Dry Chaco suffers an accelerated change due to agriculture expansion and intensification. The Dry Chaco ecoregion is characterized by high levels of endemisms and species diversity, which are the result of a variety of climates and reliefs, allowing a wide variety of environments. The amphibian group exhibits a high richness in the Dry Chaco, which has been barely studied in relation to land cover changes. We used ecological niche models (ENMs to assess the potential geographic distribution of 10 Leptodactylus species (Anura, Leptodactylidae, which are mainly distributed within the Dry Chaco. We characterized these distributions environmentally, analyzed their overlap with land cover classes, and assessed their diversity of ecoregions. Also, we evaluated how these species potential distribution is affected by the transformation of land, and quantified the proportional area of the potential distribution in protected areas. We found that temperature seasonality is the main constraint to the occurrence of the species studied, whose main habitats are savannas, grasslands and croplands. The main threats to these species are the effects of climate change over spatial patterns of seasonality, which could affect their breeding and reproduction mode; the loss of their natural habitat; the exposure to contaminants used by intensive agriculture and their underrepresentation in protected areas.

  4. A new species of Aplectana (Nematoda: Cosmocercidae) parasite of Pleurodema nebulosum (Anura: Leptodactylidae) from the Monte desert, Argentina, with a key to Neotropical species of the genus Aplectana.

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    Gomez, Mauricio D Piñeiro; González, Cynthya E; Sanabria, Eduardo A

    2017-03-27

    Here we describe a new cosmocercid nematode, Aplectana nebulosa sp. nov., from the small and large intestines of Pleurodema nebulosum (Anura: Leptodactylidae), from the Monte desert of San Juan, Argentina. The new species belongs to the Aplectana group that possesses a gubernaculum and unpaired adcloacal papilla anteriorly to cloaca. It resembles A. membranosa, A. paraelenae and A. travassosi by the presence of four adcloacal papillae, but differs from those species by the following characters: number and arrangement of precloacal papillae; number and arrangement of postcloacal papillae; shape and size of spicules and gubernaculum, and by the presence of lateral alae in caudal region of males. The description of the new species is based on light microscopy and scanning electron microscopy (SEM) and we also provide a key to Neotropical species of Aplectana.

  5. A new species of Eleutherodactylus from Guiana (Leptodactylidae, Anura)

    NARCIS (Netherlands)

    Hoogmoed, M.S.; Lynch, J.D.; Lescure, J.

    1977-01-01

    Eleutherodactylus gutturalis nov. spec., belonging to the E. fitzingeri group and characterised by a black to grey throat with a median white stripe, a shagreened dorsum with larger tubercles interspersed, absence of digital webbing, relatively long legs, and uniformly coloured concealed parts of th

  6. First records of five species of the genus Eleutherodactylus Duméril and Bibron, 1841 (Anura, Leptodactylidae for Bolivia

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    De la Riva, Ignacio

    2004-12-01

    Full Text Available Five species of the genus Eleutherodactylus (Anura, Leptodactylidae are reported from Bolivia for the first time: E. altamazonicus from Departments Pando and La Paz; E. carvalhoi from Cochabamba; and E. ockendeni, E. skydmainos and E. zimmermanae from Pando. New departmental records are provided for other species: E. cruralis for Department Pando, E. danae for Beni and La Paz, E. platydactylus for Beni, E. toftae for Pando and La Paz and E. ventrimarmoratus for La Paz. Currently, 25 species of Eleutherodactylus are known in Bolivia. The taxonomic status of some species remains uncertain, new species are being described and others are still to be discovered. Therefore, the actual number of Bolivian Eleutherodactylus species is still unknown.En este trabajo se publican los primeros registros de cinco especies del género Eleutherodactylus (Anura, Leptodactylidae para Bolivia: E. altamazonicus en los Departamentos de Pando y La Paz; E. carvalhoi en Cochabamba; y E. ockendeni, E. skydmainos y E. zimmermanae en Pando. Además, se aportan las primeras citas de E. cruralis para el Departamento de Pando, de E. danae para Beni y La Paz, de E. platydactylus para Beni, de E. toftae para Pando y La Paz y de E. ventrimarmoratus para La Paz. La diversidad conocida de Eleutherodactylus en Bolivia es de 25 especies, aunque los problemas taxonómicos sin resolver, las especies en descripción y el alto número de especies aún no citadas que se considera probable encontrar, hacen que aún desconozcamos la verdadera diversidad de este género en Bolivia.

  7. The sperm of Hylodinae species (Anura, Leptodactylidae): Ultrastructural characteristics and their relevance to interspecific taxonomic relationships

    Indian Academy of Sciences (India)

    O Aguiar-Jr; A A Giaretta; S M Recco-Pimentel

    2006-09-01

    Hylodinae leptodactylids (sensu Lynch 1971) form a group of diurnal frogs, which is hypothesized on the basis of morphological traits to be the closest relatives of the dendrobatid frogs. Our study describes ultrastructural characteristics of sperm from three hylodine species (Hylodes phyllodes, Crossodactylus sp. n. and Megaelosia massarti) to reassess the intergeneric relationships within the Hylodinae, as well as the supposed relationship between the Hylodinae and Dendrobatidae. The ultrastructure of the sperm is very similar among the three species and is indicative of its conserved nature within the Hylodinae. The structure of the acrosomal complex was very similar to that of other leptodactylid species, to most of the remaining species included in the Bufonoidea lineage, and also to that observed in the dendrobatid species examined so far. Since such a structure has been considered a plesiomorphic trait, it contributes little to our understanding of the relationships between the Hylodinae and Dendrobatidae. The flagellar apparatus of Crossodactylus sp. n. is very similar to that of most leptodactylids. The sperm of Megaelosia massarti and Hylodes phyllodes display a distinctive condition in their axial and juxtaxonemal fibers. This distinctive flagellar condition expands the already known variability in sperm structure within the Leptodactylidae.

  8. Metamorfosis del aparato digestivo de larvas carnívoras de Ceratophrys cranwelli (Anura: Leptodactylidae

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    Ulloa Kreisel, Zandra E.

    2000-12-01

    Full Text Available Las larvas carnívoras de Ceratophrys cranwelli presentan un tubo digestivo más corto que la mayoría de las larvas de anuros, tiene 6 veces la longitud del cuerpo del renacuajo y se caracteriza también por tener un estómago larval. El presente trabajo tiene como objetivo el determinar el grado de transformaciones en la cavidad bucofaríngea y tubo digestivo en larvas de esta especie durante la metamorfosis y comparar las estructuras digestivas estudiadas en otras especies de Leptodactylidae de la subfamilia Ceratophryinae y especies con otros hábitos alimenticios. Carnivorous larvae from Ceratophrys cranwelli present a digestive tube shorter than most of the anuran larvae, have 6 times a tadpole’s body length and they are also characterized by the presence of a larval stomach. The aim of this work is determine the grade of transformations in the buccopharyngeal cavity and digestive tube during the metamorphosis in larvae of this species and compare the digestive structures studied in other species of Leptodactylidae of the subfamily Ceratophryinae and another species with different diets.

  9. Evaluation of the use of Leptodactylus ocellatus (Anura: Leptodactylidae) frog tissues as bioindicator of metal contamination in Contas River, Northeastern Brazil.

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    Correia, Lívia O; Siqueira Júnior, Sérgio; Carneiro, Paulo L S; Bezerra, Marcos A

    2014-12-01

    This paper presents a study on the viability of the use of tissues of the Leptodactylus ocellatus species (Anura Leptodactylidae) as a bioindicator of metal pollution. The study is based on the determination and correlation of the concentrations of manganese, chromium, zinc, nickel, copper and iron in sediments and tissues (skin, muscles and viscera) of the frog Leptodactylus ocellatus collected in the middle region of the Contas River in Bahia, Brazil. The highest levels of the metals studied were found in the viscera of this animal. In this tissue, a higher correlation of the concentration of these metals with those found in sediments was also observed. The concentrations of elements found in the skin and muscles of these amphibians have revealed no correlation with the sediment where they were collected. According to the results obtained, the viscera of the L. ocellatus species presents itself as a good bioindicator of contamination by the metals studied.

  10. Dieta de Leptodactylus ocellatus (Linnaeus, 1758 (Anura:Leptodactylidae en un humedal del oeste de Argentina

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    Eduardo A. Sanabria

    2013-05-01

    Full Text Available El presente trabajo estudia la dieta de una población de Leptodactylus ocellatus de los Humedales de Zonda, San Juan, al oeste de Argentina. Se analizaron 35 estómagos, las presas fueron clasificadas y los individuos se midieron en ancho y largo para calcular su volumen con la fórmula de la esfera elipsoide; además, se estimó la frecuencia de ocurrencia y abundancia. Se calcularon índices de diversidad, de similitud, amplitud de nicho e importancia relativa (IRI. Los presas mas importantes fueron: Hymenoptera, Anura, Coleoptera. Las presas con mayor porcentaje de presencia fueron los Hymenoptera Formicidae que representaron el 22,4%. No se encontró una relación significativa entre el ancho de la boca del depredador y el tamaño medio de la presa. La dieta observada en ambos sexos resultó similar.

  11. Dieta y parasitismo de Leptodactylus diptyx (Anura: Leptodactylidae del nordeste argentino Diet and parasitism of Leptodactylus diptyx (Anura: Leptodactylidae from Northeastern Argentina

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    Víctor Hugo Zaracho

    2012-12-01

    Full Text Available Diversos aspectos de la historia natural de especies del grupo Leptodactylus marmoratus son escasamente conocidos y la poca información existente aborda principalmente los de la biología reproductiva. El objetivo de este trabajo es aportar información acerca de la dieta y del parasitismo de poblaciones de Leptodactylus diptyx del nordeste argentino. Para el estudio trófico, se analizó el contenido estomacal e intestinal de 22 individuos adultos, mientras que para el estudio parasitario, se examinó el tubo digestivo de 40 individuos. Se registró un total de 91 presas, clasificadas en 17 categorías, entre los cuales los himenópteros formícidos fueron los más numerosos (45% y frecuentes (55%. Otras presas importantes fueron colémbolos, coleópteros y arañas. Los valores de diversidad de presas (índice de Shannon y amplitud del nicho (índice de Levins fueron 2.06 y 4.29, respectivamente. El 57.5% de los individuos examinados resultó positivo al examen de endoparásitos, entre los que se incluyen nematodos y acantocefalos. Leptodactylus diptyx representa un nuevo hospedador para los nematodos Cosmocerca sp. y Aplectana sp.The natural history of the Leptodactylus marmoratus species group is poorly known, and there is scarce available information mainly referred to aspects of the reproductive biology. The objective of this study was to contribute to the knowledge of the trophic biology and of the parasitism of Leptodactylus diptyx populations from Northeastern Argentina. The stomach and intestine contents of 22 adult individuals were analyzed for the trophic study, while the alimentary canal and body cavity of 40 individuals were examined for parasites. The diet consisted of 17 different prey items, including mainly Formicidae hymenopterans, collembolans, coleopterans, and spiders. The values of prey diversity calculated by Shannon's index (H' and niche amplitude by Levins's index were 2.06 and 4.29, respectively. The 57.5% of the

  12. Molecular phylogeny and karyotype differentiation in Paratelmatobius and Scythrophrys (Anura, Leptodactylidae).

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    Lourenço, L B; Bacci-Júnior, M; Martins, V G; Recco-Pimentel, S M; Haddad, C F B

    2008-03-01

    Paratelmatobius and Scythrophrys are leptodactylid frogs endemic to the Brazilian Atlantic forest and their close phylogenetic relationship was recently inferred in an analysis that included Paratelmatobius sp. and S. sawayae. To investigate the interspecific relationships among Paratelmatobius and Scythrophrys species, we analyzed a mitochondrial region (approximately 2.4 kb) that included the ribosomal genes 12S and 16S and the tRNAval in representatives of all known localities of these genera and in 54 other species. Maximum parsimony inferences were done using PAUP* and support for the clades was evaluated by bootstrapping. A cytogenetic analysis using Giemsa staining, C-banding and silver staining was also done for those populations of Paratelmatobius not included in previous cytogenetic studies of this genus in order to assess their karyotype differentiation. Our results suggested Paratelmatobius and Scythrophrys formed a clade strongly supported by bootstrapping, which corroborated their very close phylogenetic relationship. Among the Paratelmatobius species, two clades were identified and corroborated the groups P. mantiqueira and P. cardosoi previously proposed based on morphological characters. The karyotypes of Paratelmatobius sp. 2 and Paratelmatobius sp. 3 described here had diploid chromosome number 2n = 24 and showed many similarities with karyotypes of other Paratelmatobius representatives. The cytogenetic data and the phylogenetic analysis allowed the proposal/corroboration of several hypotheses for the karyotype differentiation within Paratelmatobius and Scythrophrys. Namely the telocentric pair No. 4 represented a synapomorphy of P. cardosoi and Paratelmatobius sp. 2, while chromosome pair No. 5 with interstitial C-bands could be interpreted as a synapomorphy of the P. cardosoi group. The NOR-bearing chromosome No. 10 in the karyotype of P. poecilogaster was considered homeologous to chromosome No. 10 in the karyotype of Scythrophrys sp

  13. Un nuevo Eleutherodactylus (Anura, Leptodactylidae de la Cordillera de Mérida, Andes de Venezuela

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    Chacón-Ortiz, A.

    2004-06-01

    Full Text Available A new frog of the genus Eleutherodactylus is described from the Cordillera de Mérida, Venezuelan Andes. The species is distinguished from others by its moderate size, first finger equal or shorter than second, basal webbing on toes, and dominant colour immaculate brown or with a few spots. The species is compared with the groups unistrigatus and conspicillatus, but not assigned to either of them. A distribution map and a sonogram (of the song are presented. Comments about current knowledge of frogs of the genus Eleutherodactylus in Venezuela are provided.Se describe una nueva rana del género Eleutherodactylus de la Cordillera de Mérida, Andes de Venezuela. La especie se distingue del resto de congéneres por su tamaño moderado, primer dedo de la mano igual o más corto que el segundo, palmeadura pedal basal, y color dominante marrón uniforme o con pocas manchas. Se compara la especie con los grupos unistrigatus y conspicillatus, pero no se asigna a ninguno de ellos. Se presenta un mapa de distribución y un sonograma del canto. Se comenta brevemente sobre el conocimiento actual de las ranas del género Eleutherodactylus en Venezuela.

  14. Helminth fauna of Leptodactylus syphax (Anura: Leptodactylidae) from Caatinga biome, northeastern Brazil.

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    Lins, Aline Gouveia de Souza; Aguiar, Aline; Morais, Drausio Honorio; Firmino da Silva, Lidiane Aparecida; Ávila, Robson Waldemar; Silva, Reinaldo José da

    2017-01-01

    Leptodactylus syphax is distributed in central, southeastern and northeastern Brazil, eastern Bolivia and southern Paraguay, occupying open areas and rock outcrops, in rock cavities and termite burrows. We collected 21 frogs from the Caatinga region of the state of Ceará, northeastern Brazil, and 7,021 helminths were recovered from 18 of these hosts (overall prevalence = 85.7%). Six helminth taxa were recovered, as follows: Aplectana membranosa (n = 3,756); Schrankiana formosula (n = 3,176); larvae of Physaloptera sp. (n = 43); unidentified nematode larvae (n = 7); digenean metacercariae of Lophosicyadiplostomum sp. (n = 2); and cystacanths of Acanthocephala (n = 37). The similarity of helminth composition between L. syphax from the Caatinga and other species of the L. fuscus group showed that some anurans were clustered according to parasite species and others according to geographic locality. This study presents new helminth records for the Neotropical region, thus helping in understanding the pattern of species distribution, and it increases the knowledge of parasites associated with amphibians.

  15. Metamorfosis del aparato digestivo de larvas carnívoras de Ceratophrys cranwelli (Anura: leptodactylidae)

    OpenAIRE

    Ulloa Kreisel, Zandra E.

    2001-01-01

    Las larvas carnívoras de Ceratophrys cranwelli presentan un tubo digestivo más corto que la mayoría de las larvas de anuros, tiene 6 veces la longitud del cuerpo del renacuajo y se caracteriza también por tener un estómago larval. El presente trabajo tiene como objetivo el determinar el grado de transformaciones en la cavidad bucofaríngea y tubo digestivo en larvas de esta especie durante la metamorfosis y comparar las estructuras digestivas estudiadas en otras especies de Leptodactylidae de ...

  16. Reproductive behavior of Leptodactylus mystacinus (Anura, Leptodactylidae with notes on courtship call of other Leptodactylus species Biologia reprodutiva de Leptodactylus mystacinus (Anura, Leptodactylidae com notas sobre o canto de corte de outras espécies de Leptodactylus

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    Júlio C. de Oliveira Filho

    2008-12-01

    Full Text Available Here we present data on the reproductive behavior of Leptodactylus mystacinus (Burmeister, 1861, including details on courtship behavior. We also describe and compared the courtship calls of L. mystacinus, L. furnarius Sazima & Bokermann, 1978 and Leptodactylus sp. (L. aff. andreae. Field works were conducted in Uberlândia (central Brazil. During courtship, a female approaches a calling male and is led to a previously excavated chamber; a female can approach a silent male that beat his hands and/or feet on the ground as well. The courtship call of L. mystacinus consists of one single arch-shaped note (duration = 0.04 s repeated 258 times per minute; the courtship calls of L. furnarius (0.06 s, 84 times per minute and Leptodactylus sp. (0.15 s, 5 times per minute also are arch-shaped. The courtship behavior of L. mystacinus is similar to that of other species of the L. fuscus (Schneider, 1799 group; unique to it is that males can beat his hands and/or feet on the ground while courting. The male behavior of conducting the female to a previously excavates chamber and the arch-shaped courtship call may represent other shared derived features of members of the L. fuscus group, including the former Adenomera species.Aqui apresentamos dados sobre o comportamento reprodutivo de Leptodactylus mystacinus (Burmeister, 1861, incluindo detalhes sobre o comportamento de corte; também descrevemos e comparamos o canto de corte de L. mystacinus, L. furnarius Sazima & Bokermann, 1978 e Leptodactylus sp. (L. aff. andreae. O trabalho de campo foi realizado em Uberlândia (Central Brasil. Durante a corte, a fêmea aproxima-se de um macho que vocaliza e é levada para uma câmara previamente escavada; uma fêmea pode se aproximar de um macho silente que bate as mãos e/ou pés no solo repetidamente. O canto de corte de L. mystacinus consiste de uma única nota em forma de arco (duração = 0.04 s repetida 258 vezes por minuto; os cantos de corte de L. furnarius (0

  17. Ultrastructure variation in the spermatozoa of Pseudopaludicola frogs (Amphibia, Anura, Leptodactylidae), with brief comments on its phylogenetic relevance.

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    dos Santos, Julio Sérgio; Introíni, Gisele Orlandi; Veiga-Menoncello, Ana Cristina Prado; Recco-Pimentel, Shirlei Maria

    2015-12-01

    The taxonomic history of the small frogs of the genus Pseudopaludicola from South America has been controversial. Phylogenetic inferences based on molecular data have identified four Pseudopaludicola clades, correlating with the known variation in karyotypes (2n = 22, 20, 18, and 16). In this study, the ultrastructure of the spermatozoa was analyzed in 12 species of the Pseudopaludicola, with the aim of describing their morphology and identifying characters that may contribute to a better understanding of the phylogenetic relationships. The spermatozoa presented marked differences in tail structures. The tails of the spermatozoa of the species with 2n = 22 chromosomes (Pseudopaludicola sp. 1 [P. pusilla group], Pseudopaludicola falcipes, P. mineira, and Pseudopaludicola saltica), as well as Pseudopaludicola ameghini and Pseudopaludicola ternetzi (2n=20), have juxta-axonemal fibers, undulating membranes and axial fibers. In contrast, in the species with 2n = 18 (P. facureae, P. giarettai, Pseudopaludicola canga, P. atragula, and Pseudopaludicola sp. 2) and 2n = 16 (Pseudopaludicola mystacalis), there are no evident axial or juxta-axonemal fibers, but a paraxonemal rod with a thick undulating membrane, which is shorter than that found among Pseudopaludicola species. The ultrastructural morphological differences observed in the spermatozoa of these species may be phylogenetically informative, given that they coincide with the consensus phylogeny of the group and appear to represent a progressive simplification of the spermatozoon.

  18. Intra-generic and interspecific karyotype patterns of Leptodactylus and Adenomera (Anura, Leptodactylidae) with inclusion of five species from Central Amazonia.

    Science.gov (United States)

    Coelho, Ana Carolina; de Mattos, Thais Lemos; Viana, Patrik; Terencio, Maria Leandra; Schneider, Carlos Henrique; Menin, Marcelo; Gross, Maria Claudia

    2016-02-01

    The genera Leptodactylus and Adenomera comprise 92 species distributed throughout the Neotropical region. These species have a modal diploid chromosome number 2n = 22. However, chromosome rearrangements are evident in the differentiation of five intra-generic groups in the genus Leptodactylus (L. fuscus, L. latrans, L. marmoratus (formally composed by the species of the genus Adenomera), L. melanonotus, L. pentadactylus), yet it is not clear if there is a karyotype pattern for each group. Aiming to understand the intra-generic and interspecific karyotype patterns of Leptodactylus and Adenomera, cytogenetic analyses were performed in A. andreae, L. macrosternum, L. pentadactylus, L. petersii, and L. riveroi using conventional staining, C-banding, nucleolus organizer region (NOR) and hybridization in situ fluorescent (FISH). The karyotype of Leptodactylus riveroi was described for the first time. Adenomera andreae had 2n = 26, while the remaining species 2n = 22. The NOR was found on pair No. 8 of A. andreae, L. macrosternum, L. pentadactylus, and L. riveroi, whereas L. petersii had it on pairs Nos. 6 and 10. These locations were confirmed by the FISH with 18S rDNA probe, except for pair No. 10 of L. petersii. The C-banding pattern was evident at the centromeres of chromosomes of all species and some interspecific variations were also observed. 2n = 22 was observed in the species of the L. latrans group, as well as in the intra-generic groups L. fuscus and L. pentadactylus; in the L. melanonotus group there were three diploid chromosome numbers 2n = 20, 22 and 24; and a larger variation in 2n was also evident in the L. marmoratus group.

  19. Redescripción de la morfología larval externa de dos especies del grupo de Leptodactylus fuscus (Anura, Leptodactylidae

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    José A. Langone

    2005-10-01

    Full Text Available The larvae of Leptodactylus gracilis (D’Orbigny y Bibron, 1840 and L. mystacinus Bumeister, 1861 are re-described and compared with previous descriptions noting intraspecific variation in oral disccharacteristics (arrangement of papillae and rows of cornified teeth. The external morphological analysis of larvae of the Leptodactylus fuscus group suggest that the lack of comparable descriptions among species, as well as the lack of analyses of theirintraspecific variation, limits the use of larval characteristics for diagnostic purposes.

  20. O osteocrânio de Proceratophrys boiei (Wied-Neuwied, P. appendiculata (Günther, P. melanopogon (Miranda-Ribeiro e P. laticeps Izecksohn & Peixoto (Anura, Leptodactylidae The osteocranium of Proceratophrys boiei (Wied-Neuwied, P. appendiculata (Günther, P. melanopogon (Miranda-Ribeiro, and P. laticeps Izecksohn & Peixoto, (Anura, Leptodactylidae

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    Eugenio Izecksohn

    2005-03-01

    Full Text Available Foram comparados alguns ossos do crânio de quatro espécies de Proceratophrys Miranda-Ribeiro, 1920 que compartilham longos apêndices palpebrais, como sejam: P. boiei (Wied-Neuwied, 1825, P. appendiculata (Günther, 1873, P. melanopogon (Miranda-Ribeiro, 1926 e P. laticeps Izecksohn & Peixoto, 1981. Com base na forma dos frontoparietais, (com cristas laterais elevadas, na posição dos cantos dos quadratojugais em relação ao plano vertical dos côndilos occipitais, na ornamentação das superfícies cranianas (com tubérculos e grânulos, e na presença de fossetas maxilares posteriores ventrais, P. boiei, P. appendiculata e P. melanopogon foram consideradas em um mesmo grupo. P. laticeps, entretanto, por apresentar arcadas temporais completas (semelhante a Ceratophrys Wied-Neuwied, 1824, cantos dos quadratojugais posteriores ao plano vertical dos côndilos occipitais, superfícies cranianas rugosas e ausência de fossetas maxilares posteriores ventrais, é considerada pertencente a um grupo separado.Skull bones of four Proceratophrys Miranda-Ribeiro, 1920 species sharing long dermal appendages on eyelids - P. boiei (Wied-Neuwied, 1825, P. appendiculata (Günther, 1873, P. melanopogon (Miranda-Ribeiro, 1926, and P. laticeps Izecksohn & Peixoto, 1981 - are herein studied. Proceratophrys boiei, P. appendiculata and P. melanopogon share higher lateral crests on the frontoparietals, quadratojugal corners similarly positioned in relation to the vertical level of the occipital condiles, cranial bones with granules and tubercles, and maxillaries with ventro-posterior pits, hence being considered members of a single group; P. laticeps, given the presence of temporal arcades (similar to Ceratophrys Wied-Neuwied, 1824, quadratojugal corners posterior to the vertical level of occipital condiles, wrinkled skull bones, and maxilaries without ventro-posterior pits, is nonetheless considered as a member of a distinct group.

  1. Reproductive biology of Pleurodema guayapae (Anura: Leptodactylidae: Leiuperinae

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    Julián Alonso Valetti

    2014-03-01

    Full Text Available Pleurodema guayapae is a species that inhabits saline environments and semidesert zones from central Argentina. To date, the knowledge about the reproductive biology of this species is very poor, and our aim is to contribute to its knowledge with the description of some important reproductive aspects. For this, field work was undertaken in an area near to Patquía, La Rioja province. Sampling was undertaken during three summer periods (2006-2007; 2007-2008; 2008-2009 in Chamical-Patquía area, where we could find reproductively active populations. We observed and described breeding sites, type of clutch, process of foam nest construction, clutch and egg number and sizes, and hatching time and stage. Behaviour observations were performed from the time that males began to call until the pairs ended up the foam nests building, and layed the eggs. Additionally, one amplected pair was observed and filmed in the process of foam nest construction, and four amplectant pairs were collected and separatelly placed in plastic containers, for nests observations in the laboratory. Hatching time was based on three different foam nests of known age. We found that P. guayapae populations were acoustically active only after a rainfall. Its breeding sites were represented by ephemeral ponds of fresh water, product of rains. The males emitted their calls inside or outside these ponds. A detailed description of the foam nest construction process by both females and males was made. The clutches were in dome-shaped foam nest type of 6-9cm in diameter and 1-3cm in height, some of which were in communal nests. The nests had an average of 1 137 pigmented eggs. This species showed a short hatching time. Our results allow us to conclude that this species should be considered an extreme explosive breeder. Our results are discussed with others obtained for related species.

  2. Cytogenetic analysis of Cycloramphus boraceiensis Heyer (Anura, Leptodactylidae

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    Ana Paula Zampieri Silva

    2001-03-01

    Full Text Available Cytogenetic studies on Cycloramphus boraceiensis Heyer, 1983 collected in Picinguaba, Ubatuba, State of São Paulo are presented. The species has 2n=26 karyotype formed by metacentrics, submetacentrics, and one telocentric pair which carries Ag-NORs. The C-banding patterns is also described.

  3. Helmintos parásitos de Telmatobius jelskii (Peters (Anura, Leptodactylidae de Lima, Perú Helminth parasites of Telmatobius jelskii (Peters (Anura, Leptodactylidae from Lima, Peru

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    José Iannacone

    2003-03-01

    Full Text Available A quantitative research of parasites of 67 endemic frog Telmatobius jelskii (Peters, 1863 collected from Laguna Tucto (76°46'11"W, 10°39'11"S where Pativilca River is originated was conducted, and was located in the Province of Oyon, high Andean area from the Department of Lima, Peru during September-October 2000. Of the frogs collected, 23 were females and 44 males. Male showed a length between 5.2 ± 0.5 cm (range = 4.0-6.4 cm and female between 5.5 ± 1 cm (range = 3.9-7.6 cm and were not found differences between both sexes. 86 specimens of parasite and three species in total during all the survey were collected. 28 hosts were infected (41.8%. twenty-five hosts (37.3% showed infection with one parasite species, and three (4.5% had two parasite species. Three parasite species were found: Gorgoderina parvicava Travassos, 1922 (Digenea: Gorgoderidae (Prevalence = 40.3%; mean Intensity = 3.1; mean abundance = 1.2, Cylindrotaenia americana Jewell, 1916 (Cestoda: Proteocephalidae (Prevalence = 3%; mean Intensity = 1; mean abundance = 0.02 and Aplectana hylambatis (Baylis, 1927 (Nematoda: Cosmocercidae (Prevalence = 3%; mean Intensity = 1; mean abundance = 0.02. G. parvicava had an overdispersed distribution and was the dominant species. An effect of sex and length with prevalence and mean abundance of infection of G. parvicava was not found. The relationship of helminthes parasites with T. jelskii is discussed. G. parvicava and C. americana are new records for T. jelskii.

  4. Hábitos alimentarios de infantiles de Pleurodema nebulosum (Anura: Leptodactylidae, en Matagusanos, San Juan, Argentina

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    Eduardo Sanabria

    2013-04-01

    Full Text Available Los hábitos alimentarios de Pleurodema nebulosum en el oeste de Argentina son desconocidos. El objetivo de este trabajo es analizar la dieta de una población de infantiles de P. nebulosum. Se analizaron 34 estómagos, se clasificaron taxonómicamente sus presas y se midieron (ancho y largo, se calculó su volumen con la fórmula de la esfera elipsoide, se estimó además la frecuencia de ocurrencia y abundancia. Los IRI más importantes fueron: Hemiptera (1867, Hymenoptera (hormigas (1431, Coleoptera (127, entre otros. Las presas que presentaron mayor porcentaje de frecuencia fueron los Hymenoptera (48,5%, Hemiptera (26,9% y Coleoptera (10,8%. El valor de diversidad media fue de 0.19 (SD=0,2 y la amplitud del nicho trófico fue de 3,17. Este valor indicaría una posible especialización y considerando la baja diversidad encontrada, podría estar reflejando la escasa disponibilidad de presas en ese momento.

  5. Description of a new species of the genus Adenomera (Amphibia, Anura, Leptodactylidae from French Guiana

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    Renaud Boistel

    2006-01-01

    Full Text Available We describe a new species of the genus Adenomera from French Guiana. Collecting conditions, details about the localities and microhabitats are given. The advertisement call was recorded and is herein analyzed and described. Morphological and bioacoustic comparisons are drawn with other species of the genus. The new species is readily distinguished from other taxa by its distinctive coloration pattern, the occurrence of dorsolateral ridges and inguinal glands, and by the longer duration of the notes of its advertisement call. The taxonomy of Adenomera is evaluated with regard to current available knowledge.

  6. Redescription of the advertisement call of Physalaemus albifrons (Spix, 1824) (Amphibia, Anura, Leptodactylidae).

    Science.gov (United States)

    Pederassi, Jonas; Lima, Mauro Sérgio Cruz Souza; Caramaschi, Ulisses; Souza, Patrícia Dos Santos; Santos, Mayra Caroliny De Oliveira; Silva, Islaíane Costa

    2015-08-03

    The genus Physalaemus Fitzinger, 1826 is composed by 46 species occurring from north to southern South America, east of the Andes (Frost 2015). Physalaemus albifrons is morphologically differentiated from the other species mainly due to the presence of a second tarsal tubercle located nearly the tibio-tarsal articulation (Bokermann 1966). Physalaemus albifrons occurs in Brazil from north of the State of Maranhão through the states of Piauí, Ceará, Bahia, Paraíba, Pernambuco, and Alagoas, being its more austral occurrence in the State of Minas Gerais (Frost 2015). The advertisement call of P. albifrons was described by Bokermann (1966); however, the description needs improvement by applying new technologies, which we provide herein.

  7. Atividade reprodutiva de Physalaemus signifer (Anura, Leptodactylidae em ambiente temporário

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    Wogel Henrique

    2002-01-01

    Full Text Available The breeding activity of Physalaemus signifer (Girard, 1853 was monitored from July 1999 to July 2000 in a temporary pond in Palmital, Municipality of Saquarema, State of Rio de Janeiro, Atlantic Rain Forest, Brazil. Males were sexually actives only in four nights, arriving at the pond on the early rainy season. Males in amplexus were larger and spent more nights in the reproductive aggregation than solitary ones. The number of nights was correlated with the mass of the males. Males adopted satellite behavior as alternative tactic for mate acquisition. Changes between calling and satellite tactics were observed in different nights. Calling males were not larger and heavier than satellite ones. Satellite behavior seemed to be related with the order of arrival on the pond. Size and mass of males did not influence the results of fights. Resident males won the majority of agonistics combats. Three types of vocalizations are described: advertisement, territorial, and encounter calls.

  8. Aspects of gene regulation in the diploid and tetraploid Odontophrynus americanus (Amphibia, Anura, Leptodactylidae

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    Cianciarullo Aurora M.

    2000-01-01

    Full Text Available Erythropoietic and hemoglobin DNA transcriptional activities were analyzed in the diploid and the tetraploid Odontophrynus americanus. Flow cytometric analyses of DNA, RNA and mitochondrial contents showed increased genic activity in both diploid and tetraploid animals during erythropoiesis in vivo elicited by pretreatment phenylhydrazine. Generally, higher values were seen in immature tetraploid erythroid cells. On the 10th day of recovery from anemia, large amounts of messenger RNA were found in both specimens. Based on the mitochondrial content, the tetraploid cells had more intense energy metabolism than the diploid cells. Diploid O. americanus had about three times more erythroid cells than tetraploid specimens, indicating that there were differences in the regulatory mechanisms of erythroid cells. Hematological parameters showed that tetraploid cells had 30% more hemoglobin than the diploid, suggesting a regulatory mechanism of hemoglobin synthesis at the transcriptional level. Cytoplasmic inclusions resembling Heinz bodies were found in both types of cells. In the tetraploid cells they were previously found associated with RNA or RNP, suggesting that other regulatory system which controls the accumulation of nontranslated RNA transcribed in excess must be present. These differences at the physiological and molecular levels during erythropoiesis reinforce the hypothesis that speciation is occurring between diploid and tetraploid O. americanus.

  9. Behavioural responses of Odontophrynus americanus tadpoles (Anura: Leptodactylidae to fish chemical cues

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    Scarabotti, Pablo A.

    2007-02-01

    Full Text Available Las larvas de muchas especies de anfibios viven en ambientes con vegetación y de aguas turbias, donde la visibilidad es muy limitada. En estos ambientes, la utilización de señales químicas para la detección de depredadores podría ser más confiable que la utilización de señales visuales. Las larvas de Odontophrynus americanus habitan en las lagunas del valle aluvial del río Paraná Medio, Argentina, donde normalmente se dan condiciones de baja visibilidad. La hipótesis de este trabajo fue que los renacuajos de esta especie pueden detectar a los depredadores y responder subsecuentemente con conducta antipredador ante la percepción de señales químicas de los depredadores. En el presente trabajo se llevaron a cabo tres experimentos de laboratorio para evaluar si los renacuajos de O. americanus responden conductualmente al estímulo químico del pez Astyanax fasciatus. Las respuestas conductuales fueron evaluadas observando cambios en actividad, utilización de refugio y distribución espacial de los renacuajos. En presencia del estímulo químico del pez, los renacuajos redujeron su actividad en un 27%, incrementaron cinco veces la utilización de refugios, pero no exhibieron una respuesta de elusión espacial al estímulo del depredador. Las respuestas conductuales de los renacuajos de esta especie podrían reducir las probabilidades de encuentro y ataque por parte de los depredadores. Many amphibian larvae live in turbid and vegetated habitats with very limited visibility. In these habitats, the use of chemical cues for predator detection may be more reliable than visual ones. Odontophrynus americanus tadpoles inhabit floodplain ponds of the middle Paraná River, Argentina, where they frequently encounter low visibility conditions. We hypothesize that tadpoles of this species can detect predators and subsequently respond with antipredator behaviour by means of chemical cues from predators. In the present work, we ran three separate laboratory experiments to evaluate whether O. americanus tadpoles respond behaviourally to a chemical stimulus of the characid fish Astyanax fasciatus. We evaluated behavioural responses by observing changes in activity level, refuge use and spatial distribution of the tadpoles. In the presence of the fish chemical stimulus, tadpoles reduced their activity by 27% and increased refuge use approximately five-fold, but they did not exhibit spatial avoidance from the predator stimulus. The behavioural responses of the tadpoles of this species may reduce the rate of encounter and attack by predators.

  10. Descripción del canto de encuentro en Physalaemus albonotatus (Anura: Leptodactylidae de Corrientes, Argentina

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    Duré, Marta Inés

    2003-11-01

    Full Text Available Durante la época de reproducción de Physalaemus albonotatus se observaron cantando agregaciones numerosas de machos de esta especie. En algunas oportunidades se presenciaron contactos agresivos entre éstos, los cuales eran precedidos por un canto diferente al nupcial típico. En este trabajo se describe el canto de encuentro de P. albonotatus y se lo compara con el canto nupcial del mismo en una población de la provincia de Corrientes, Argentina. Existen diferencias entre ambos tipos de llamadas las que se reflejan principalmente en el número de vocalizaciones por minuto y en el incremento de la complejidad de las notas emitidas. During the breeding time period it is frequent to observe males of Physalaemus albonotatus aggregated for calling. In several opportunities was observed aggressive contact between males preceeded by a different call than nuptial vocalization. In this paper we describe the encounter call of P. albonotatus from a population from Corrientes province, Argentina and compare it with the typical nuptial call of this species. Both types of vocalizations exhibit differences in the call number per minute and in the complexity of the emitted notes.

  11. A new species of semiarboreal toad of the Rhinella festae group (Anura, Bufonidae) from the Cordillera Azul National Park, Peru

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    Cusi, Juan C.; Moravec, Jiří; Lehr, Edgar; Gvoždík, Václav

    2017-01-01

    Abstract A new semiarboreal species of the Rhinella festae group is described from montane forests of the Cordillera Azul National Park between 1245 and 1280 m a.s.l. in the Cordillera Oriental, San Martín region, northern Peru. The new species is morphologically and genetically compared with members of the Rhinella acrolopha group (former genus Rhamphophryne) and members of the R. festae group. The new species is characterized by its large size (female SVL 47.1–58.3 mm, n = 4), eight presacral vertebrae, fusion of the sacrum and coccyx, long protuberant snout, snout directed slightly anteroventral in lateral view, cranial crests moderately developed, absence of occipital crest, presence of tympanic membrane, dorsolateral rows of small conical tubercles extending from parotoid gland to groin, hands and feet with long digits, fingers basally webbed and toes moderately webbed. Phylogenetically it is a member of the R. festae group which is most closely related to R. chavin and R. yanachaga from Peru. Morphologically the new species shares similarities with R. tenrec and R. truebae, members of the R. acrolopha group from Colombia. PMID:28769671

  12. A new species of the Rhinella margaritifera species group (Anura, Bufonidae) from the montane forest of the Selva Central, Peru.

    Science.gov (United States)

    Moravec, Jiří; Lehr, Edgar; Cusi, Juan Carlos; Córdova, Jesús H; Gvoždík, Václav

    2014-01-01

    We describe a new species of the bufonid toad genus Rhinella from transition montane forest of the buffer zones of the Yanachaga-Chemillén National Park and the Pui Pui Protected Forest (eastern slopes of Andes, Selva Central, Peru). The new species belongs to the Rhinella margaritifera species group (confirmed by mtDNA data) and differs from all its members by the absence of tympanic membrane and tympanic annulus. It is characterized by medium size (SVL 57.5-65.5 mm, n = 5), moderately developed cranial crests, absence of neural crest of vertebrae, absence of bone protrusion at angle of jaw, presence of lateral rows of enlarged tubercles, and absence of subgular vocal sac and vocal slits in males. In addition, based on the molecular phylogenetic analyses of selected Rhinella species we propose the monophylum containing R. chavin, R. festae, R. macrorhina, R. manu, R. nesiotes, R. rostrata, and R. yanachaga as a new species group under the name Rhinella festae species group.

  13. A new Dendropsophus Fitzinger, 1843 (Anura: Hylidae) of the parviceps group from the lowlands of the Guiana Shield.

    Science.gov (United States)

    Fouquet, Antoine; Orrico, Victor Goyannes Dill; Ernst, Raffael; Blanc, Michel; Martinez, Quentin; Vacher, Jean-Pierre; Rodrigues, Miguel Trefaut; Ouboter, Paul; Jairam, Rawien; Ron, Santiago

    2015-12-01

    Many Amazonian frog species that are considered widely distributed may actually represent polyspecific complexes.. A minute tree frog from the Guiana Shield originally assigned to the allegedly widely distributed Dendropsophus brevifrons proved to be a yet undescribed species within the D. parviceps group. We herein describe this new species and present a phylogeny for the D. parviceps group. The new species is diagnosed from other Dendropsophus of the parviceps group by its small body size (19.6-21.7 mm in males, 22.1-24.5 mm in females), thighs dorsally dark grey with cream blotches without bright yellow patch, absence of dorsolateral and canthal stripe, and an advertisement call comprising trills (length 0.30-0.35 s) composed of notes emitted at a rate of 131-144 notes/s, generally followed by click series of 2-3 notes. Its tadpole is also singular by having fused lateral marginal papillae and absence of both labial teeth and submarginal papillae. Genetic distances (p-distance) are >5.3% on the 12S and >9.3% on the 16S from D. brevifrons, its closest relative. This species occurs from the Brazilian state of Amapá, across French Guiana and Suriname to central Guyana and is likely to also occur in adjacent Brazilian states and eastern Venezuela. This species is not rare but is difficult to collect because of its arboreal habits and seasonal activity peaks.

  14. Osteology of Atelopus muisca (Anura, Bufonidae) from Colombia.

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    Hoyos, Julio Mario; Medina, Paola; Schoch, Paulette

    2015-01-09

    The first comprehensive description of the skeleton of Atelopus muisca Rueda-Almonacid & Hoyos, 1991 (Bufonidae, Anura) from the Chingaza Natural National Park (Colombia) is provided, and comparisons with some characters described for this species by Coloma and related frogs of the group A. ignescens are done. The humerus of male presenting more developed crista ventralis and crista lateralis, and the articulation of the frontoparietal bones showed the presence of sexual dimorphism. These are character not described for species of the genus Atelopus belonging to the group A. ignescens. A. ignescens. Among the other osteological characters we did not find unique feature for the species. 

  15. Taxonomic status of Leptodactylus ochraceus, a forgotten species (Anura: Leptodactylidae A posição taxonômica de Leptodactylus ochraceus, uma espécie esquecida (Anura: Leptodactylidae

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    Ulisses Caramaschi

    2008-09-01

    Full Text Available The taxonomic status of Leptodactylus ochraceus Lutz, 1930, a forgotten leptodactylid frog species, known only from the holotype, is reviewed. The holotype and the original color plate are described and the type locality is discussed and revised. The species is considered valid and distinct from all leptodactylids, leiuperids, cycloramphids, and ceratophrids occurring in Northeastern Brazil.A posição taxonômica de Leptodactylus ochraceus Lutz, 1930, uma espécie de anfíbio leptodactilídeo esquecida, conhecida apenas do holótipo, é revisada. O holótipo e a prancha colorida original são descritos e a localidade tipo é discutida e atualizada. A espécie é considerada válida e distinta de todos os leptodactilídeos, leiuperídeos, cicloranfídeos e ceratofrídeos que ocorrem no Nordeste do Brasil.

  16. Altered development, oxidative stress and DNA damage in Leptodactylus chaquensis (Anura: Leptodactylidae) larvae exposed to poultry litter.

    Science.gov (United States)

    Curi, L M; Peltzer, P M; Martinuzzi, C; Attademo, M A; Seib, S; Simoniello, M F; Lajmanovich, R C

    2017-09-01

    Poultry litter (PL), which is usually used as organic fertilizer, is a source of nutrients, metals, veterinary pharmaceuticals and bacterial pathogens, which, through runoff, may end up in the nearest aquatic ecosystems. In this study, Leptodactylus chaquensis at different development stages (eggs, larval stages 28 and 31 here referred to as stages I, II and III respectively) were exposed to PL test sediments as follows: 6.25% (T1), 12.5% (T2); 25% (T3); 50% (T4); 75% (T5); 100% PL (T6) and to dechlorinated water as control. Larval survival, development endpoints (growth rate -GR-, development rate -DR-, abnormalities), antioxidant enzyme activities (Catalase -CAT- and Glutathione-S-Transferase -GST-), and genotoxic effect (DNA damage index by the Comet assay) were analyzed at different times. In stage I, no egg eclosion was observed in treatments T3-T6, and 50% of embryo mortality was recorded after 24h of exposure to T2. In stages II and III, mortality in treatments T3-T6 reached 100% between 24 and 48h. In the three development stages evaluated, the DR and GR were higher in controls than in PL treatments (T1, T2), except for those T1-treated larvae of stage II. Larvae of stage I showed five types of morphological abnormalities, being diamond body shape and lateral displacement of the intestine the most prevalent in T1, whereas larvae of stages II and III presented lower prevalence of abnormalities. In stage I, CAT activity was similar to that of control (p>0.05), whereas it was higher in T1- and T2- treated larvae of stages II and III than controls (p0.05), whereas it was inhibited in T1-treated larvae of stage II (p<0.05). T1- and T2-treated larvae of stages II and III caused higher DNA damage respect to controls (p<0.05), varying from medium to severe damage (comet types II, III and IV). These results showed that PL treatments altered development and growth and induced oxidative stress and DNA damage, resulting ecotoxic for L. chaquensis larvae. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Hyla inermis (Peters), a species hitherto erroneously referred to the Leptodactylid genus Cyclorana (Anura, Hylidae/Leptodactylidae)

    NARCIS (Netherlands)

    Straughan, I.R.

    1969-01-01

    INTRODUCTION Extensive collections of frogs from Queensland (reported in detail, Straughan, 1966) failed to include the species Cyclorana inermis (Peters), although Slevin (1955) recorded it as abundant in central Queensland. However a widely ranging species of ground Hyla (undescribed in that genus

  18. Cytotoxic Activity and Antiproliferative Effects of Crude Skin Secretion from Physalaemus nattereri (Anura: Leptodactylidae on in vitro Melanoma Cells

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    Andréa Cruz e Carvalho

    2015-10-01

    Full Text Available Anuran secretions are rich sources of bioactive molecules, including antimicrobial and antitumoral compounds. The aims of this study were to investigate the therapeutic potential of Physalaemus nattereri skin secretion against skin cancer cells, and to assess its cytotoxic action mechanisms on the murine melanoma cell line B16F10. Our results demonstrated that the crude secretion reduced the viability of B16F10 cells, causing changes in cell morphology (e.g., round shape and structure shrinkage, reduction in mitochondrial membrane potential, increase in phosphatidylserine exposure, and cell cycle arrest in S-phase. Together, these changes suggest that tumor cells die by apoptosis. This skin secretion was also subjected to chromatographic fractioning using RP-HPLC, and eluted fractions were assayed for antiproliferative and antibacterial activities. Three active fractions showed molecular mass components in a range compatible with peptides. Although the specific mechanisms causing the reduced cell viability and cytotoxicity after the treatment with crude secretion are still unknown, it may be considered that molecules, such as the peptides found in the secretion, are effective against B16F10 tumor cells. Considering the growing need for new anticancer drugs, data presented in this study strongly reinforce the validity of P. nattereri crude secretion as a rich source of new anticancer molecules.

  19. Un nuevo y peculiar Odontophrynus de la sierra de Guasayán, Santiago del Estero, Argentina (Anura: Leptodactylidae

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    Cei, José M.

    1985-01-01

    Full Text Available Un examen crítico de la morfología y cariotipo de los Odontophrynus de las poblaciones de la Sierra de Guayasán, Santiago del Estero, Argentina, permite sustentar su estado específico, frente a las otras formas del conjunto diplo-tetradiploide del grupo americanus. La nueva especie diploide O. lavillai exhibe caracteres diferenciales significativos, somáticos, de estructura cutánea y de coloración. Se presentan datos ecológicos generales y una discusión de sus relaciones cariotípicas con las otras formas diplo-tetraploides del grupo.

  20. Una nueva especie de Batrachyla (Anura: Leptodactylidae: Telmatobiinae de Argentina. Relaciones filogenéticas interespecíficas

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    Basso, Néstor Guillermo

    1994-01-01

    Full Text Available A new species of telmatobiinae leptodactylid frog genus Batrachyla is described from the Nothofagus forest of Chubut province, Southern Argentina. Batrachyla fitzroya sp. nov. is more closely related to B. antartandica than to any other species of the genus. A cladistic analysis of the genus Batrachyla applying parsimony is presented using morphological and osteological characters. Polarity was based on the outgroup comparison method. The data were analysed using Farris's phylogenetic program Hennig86, using the implicit enumeration option. In the preferred phylogeny B. taeniata is the sister species of the clade B. leptopus-(B. antartandica-B. fitzroya.

  1. Una nueva especie de Batrachyla (Anura: Leptodactylidae: Telmatobiinae) de Argentina. Relaciones filogenéticas interespecíficas

    OpenAIRE

    Basso, Néstor Guillermo

    1994-01-01

    A new species of telmatobiinae leptodactylid frog genus Batrachyla is described from the Nothofagus forest of Chubut province, Southern Argentina. Batrachyla fitzroya sp. nov. is more closely related to B. antartandica than to any other species of the genus. A cladistic analysis of the genus Batrachyla applying parsimony is presented using morphological and osteological characters. Polarity was based on the outgroup comparison method. The data were analysed using Farris's phylogenetic pr...

  2. Ultrastructural Evidence of Serous Gland Polymorphism in the Skin of the Tungara Frog Engystomops pustulosus (Anura Leptodactylidae).

    Science.gov (United States)

    Delfino, Giovanni; Giachi, Filippo; Malentacchi, Cecilia; Nosi, Daniele

    2015-09-01

    Three types of serous products were detected in the syncytial cutaneous glands of the leptodactylid tungara frog, Engystomops pustulosus: type Ia, granules with wide halos and variable density cores; type Ib, high density granules without halos; and type II, vesicles containing a finely dispersed product. Ultrastructural evidence revealed that these products were manufactured by different serous gland types and excluded that they represented different steps in the secretory cycle of a single gland type. Indeed, secretory maturation affecting the products released by the Golgi apparatus proceeded through different mechanisms: confluence (vesicles), interactions between syncytium and secretory product (type Ib granules), and a combination of both processes (type Ia granules). In conclusion, this investigation of secretory maturation was shown to be a suitable approach for the identification of serous gland polymorphism and demonstrated that the tungara frog belongs to the minority of anuran species characterized by this peculiar morpho-functional trait.

  3. Toxicity of Bacillus thuringiensis var. israelensis in aqueous suspension on the South American common frog Leptodactylus latrans (Anura: Leptodactylidae) tadpoles

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    Lajmanovich, Rafael C., E-mail: lajmanovich@hotmail.com [National Council for Scientific and Technical Research (CONICET), Buenos Aires (Argentina); Faculty of Biochemistry and Biological Sciences (FBCB-UNL), Ciudad Universitaria Paraje el Pozo s/n, 3000 Santa Fe (Argentina); Junges, Celina M. [National Council for Scientific and Technical Research (CONICET), Buenos Aires (Argentina); Faculty of Biochemistry and Biological Sciences (FBCB-UNL), Ciudad Universitaria Paraje el Pozo s/n, 3000 Santa Fe (Argentina); Cabagna-Zenklusen, Mariana C. [Faculty of Biochemistry and Biological Sciences (FBCB-UNL), Ciudad Universitaria Paraje el Pozo s/n, 3000 Santa Fe (Argentina); Attademo, Andrés M.; Peltzer, Paola M. [National Council for Scientific and Technical Research (CONICET), Buenos Aires (Argentina); Faculty of Biochemistry and Biological Sciences (FBCB-UNL), Ciudad Universitaria Paraje el Pozo s/n, 3000 Santa Fe (Argentina); Maglianese, Mariana; Márquez, Vanina E.; Beccaria, Alejandro J. [Faculty of Biochemistry and Biological Sciences (FBCB-UNL), Ciudad Universitaria Paraje el Pozo s/n, 3000 Santa Fe (Argentina)

    2015-01-15

    The effects of commercial formulations of Bacillus thuringiensisvar.israelensis (Bti) on non-target organisms are still a matter of debate; in amphibians, the risks of Bti are little known. To evaluate the toxicity of a commercial liquid (aqueous suspension, AS) formulation of Bti (Introban{sup ®}) on Leptodactylus latrans tadpoles, including median lethal concentration (LC{sub 50}) and no-and lowest–observed-effect concentrations (NOEC and LOEC, respectively), as well as the possible effects of Bti on oxidative responses, erythrocytes genotoxicity, and histology of the intestines. In the laboratory, tadpoles were exposed to nominal concentrations of 0 (control), 2.5, 5, 10, 20 and 40 mg/L of formulated Bti-AS. Glutathione S-transferase (GST) and catalase (CAT) activities, as well as formation of erythrocyte nuclear abnormalities (ENAs), and histological effect were measured in tadpoles displaying survival rates >85%. L. latrans tadpoles were sensitive to exposure to Bti-AS, reaching 100% mortality after 48 h of exposure at the highest concentration. Bti-AS induced GST and CAT enzymes and genotoxicity (erythrocyte's nuclear abnormalities), and caused intestine's histopathology. Our results demonstrate that toxicity of Bti-AS is dose-dependent for L. latrans tadpoles and that sublethal exposure alters enzymes of oxidative stress, induces genotoxicity, and causes intestine damage. Further research is needed to evaluate the ecotoxicological risk of the massive use of Bti formulations on amphibian populations that commonly used suburban wastewater or urban waterbodies to reproduce and where this biopesticide is frequently applied. - Highlights: • An ecotoxicological evaluation of a Bti formulation on amphibian was conducted. • Toxicity of Bti-AS was dose-dependent for Leptodactylus latrans tadpoles. • Sublethal exposure altered the enzymes of oxidative stress (GST and CAT). • Bti-AS was genotoxic because increased MN frequencies (CO: 0.82–2.74‰). • Bti-AS caused the inflammatory infiltration in the lamina propria of intestine.

  4. Vocal repertoire of Scinax v-signatus (Lutz 1968 (Anura, Hylidae and comments on bioacoustical synapomorphies for Scinax perpusillus species group

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    Marco Antônio Peixoto

    2016-06-01

    Full Text Available Herein we describe the vocal repertoire of Scinax v-signatus, compare it to the other species belonging to the S. perpusillus species group and discuss the bioacoustical synapomorphies proposed for the group. We recorded an advertisement call and an aggressive call of S. v-signatus. The advertisement call is similar to the one described for others species of the Scinax perpusillus group. Similarly to Scinax cosenzai, the first note in the advertisement call of S. v-signatus is the longest. The aggressive call was preceded by a series of advertisement calls. We suggest that bioacoustical parameters proposed as synapomorphies for the Scinax perpusillus group are not valid, as they are also observed in species belonging to other groups within the genus.

  5. Porcentaje de catecolaminas adrenales como indicador filogenético en Leptodactylidae e Hylidae

    OpenAIRE

    Montero, Ricardo

    1986-01-01

    Se analizaron las proporciones de adrenalina y noradrenalina en las glándulas adrenales de trece especies de Leptodactylidae e Hylidae sudamericanas mediante espectrofluorimetría, encontrándose una gran auperpoblación de los valores de las distintas especies y entre las dos familias. Esto sugiere que esto no es un buen indicador filogenético y que quizá no sea conservativo desde el punto de vista evolutivo en las familias estudiadas, lo cual se contrapone a lo encontrado por Robinson y Tyler ...

  6. Porcentaje de catecolaminas adrenales como indicador filogenético en Leptodactylidae e Hylidae

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    Montero, Ricardo

    1986-01-01

    Full Text Available Se analizaron las proporciones de adrenalina y noradrenalina en las glándulas adrenales de trece especies de Leptodactylidae e Hylidae sudamericanas mediante espectrofluorimetría, encontrándose una gran superpoblación de los valores de las distintas especies y entre las dos familias. Esto sugiere que esto no es un buen indicador filogenético y que quizá no sea conservativo desde el punto de vista evolutivo en las familias estudiadas, lo cual se contrapone a lo encontrado por Robinson y Tyler (Comp. Gen. Pharmacol. 1972, 3:167-170 en Myobatrachidae y Pelodryadidae

  7. The karyotypes of five species of the Scinax perpusillus group (Amphibia, Anura, Hylidae) of southeastern Brazil show high levels of chromosomal stabilization in this taxon.

    Science.gov (United States)

    Peixoto, Marco Antônio Amorim; Lacerda, João Victor Andrade; Coelho-Augusto, Carolina; Feio, Renato Neves; Dergam, Jorge Abdala

    2015-12-01

    Based on morphological, bioacoustics, and morphological traits, the genus Scinax has been subdivided into two major clades: S. catharinae and S. ruber. The first clade includes S. catharinae and S. perpusillus groups, whereas the second clade includes S. rostratus and S. uruguayus groups. Chromosome morphology, NOR and C-banding patterns of variation support these clades. This study aims the cytogenetic characterization of five species currently included in the S. perpusillus group: Scinax sp. (gr. perpusillus), S. arduous, S. belloni, S. cosenzai, and S. v-signatus, including standard cytogenetic techniques and repetitive DNA FISH probes. All species had 2n = 24 chromosomes. Nucleolar organizing regions occurred in chromosome pair 6 in all species, but differed in their locations among some species, suggesting a putative synaponomastic character for the clade. In S. belloni, the first chromosome pair was a metacentric, contrasting with the submetacentric first pair reported in all other species of the genus. Scinax sp. (gr. perpusillus) and S. v-signatus had similar karyotypic formulae, suggesting they are related species. Scinax cosenzai had a divergent C-banding pattern. Repetitive DNA probes hybridized more frequently in chromosomal subtelomeric regions in all species indicating recent cladogenesis in these species. Karyotypic evidence indicates unreported high levels of stabilization within S. perpusillus and in S. catharinae clade, resulting in a wealth of characters potentially informative for higher phylogenetic analyses.

  8. Complete mitochondrial genome of Nanorana pleskei (Amphibia: Anura: Dicroglossidae) and evolutionary characteristics

    Institute of Scientific and Technical Information of China (English)

    Guiying CHEN; Bin WANG; Jiongyu LIU; Feng XIE; Jianping JIANG

    2011-01-01

    The complete mitochondrial genome of Nanorana pleskei from the Qinghai-Tibet Plateau was sequenced.It includes 17,660 base pairs,containing 13 protein-coding genes,two rRNAs and 23 tRNAs.A tandem duplication of tRNAMet gene was found in this mitochondrial genome,and the similarity between the two tRNAMet genes is 85.8%,being the highest in amphibian mitochondrial genomes sequenced thus far.Based on gene organization,24 types were found from 145 amphibian mitochondrial genomes.Type 1 was present in 108 species,type 11 in 11 species,types 5,16,17,and 20 each in two species,and the others each present in one species.Fifteen types were found in Anura,being the most diversity in three orders of the Lissamphibia.Our phylogenetic results using 11 protein-coding gene sequences of 145 amphibian mitochondrial genomes strongly support the monophyly of the Lissamphibia,as well as its three orders,the Gymnophiona,Caudata,and Anura,among which the relationships were ((Gymnophiona (Caudata,Anura)).Based on the phylogenetic trees,type 1 was recognized as the ancestral type for amphibians,and type 11 was the synapomorphic type for the Neobatrachia.Gene rearrangements among lineages provide meaningful phylogenetic information.The rearrangement of the LTPF tRNA gene cluster and the translocation of the ND5 gene only found in the Neobatrachia support the monophyly of this group; similarly,the tandem duplication of the tRNAMet genes only found in the Dicroglossidae support the monophyly of this family [Current Zoology 57 (6):785-805,2011].

  9. Landing on branches in the frog Trachycephalus resinifictrix (Anura: Hylidae).

    Science.gov (United States)

    Bijma, Nienke N; Gorb, Stanislav N; Kleinteich, Thomas

    2016-04-01

    Frogs (Lissamphibia: Anura) are famous for their saltatory or hopping locomotion, which is related to numerous anatomical specialisations that are characteristic for the group. However, while the biomechanics of take-off in frogs have been studied in detail, much less is known on how frogs land after a jump. Besides terrestrial and aquatic species, several lineages of frogs adopted an arboreal lifestyle and especially the biomechanics of landing on challenging, small, and unpredictable substrates, such as leaves or branches, are virtually unknown. Here we studied the landing kinematics of the arboreal frog Trachycephalus resinifictrix (Hylidae) on a wooden stick that was used to mimic a small tree branch. We observed two different landing behaviours: (1) landing on the abdomen and (2) attachment with the toes of either the forelimb or the hindlimb. In the latter case, the frogs performed a cartwheel around the stick, while they were only attached by their adhesive toe pads. We estimated the forces that act on the toes during this behaviour to be up to fourteen times the body weight of the animals. This behaviour demonstrates the remarkable adhesive capabilities of the toe pads and the body control of the frogs.

  10. Status Sistematico del Género Geobatrachus Ruthven 1915 (amphibia: Anura Status Sistematico del Género Geobatrachus Ruthven 1915 (amphibia: Anura

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    Ardila Robayo María Cristina

    1979-06-01

    expected a priori since the eggs are megalecythal and laid in reduced numbers in protected places, in accordance with the scare opportunities for aquatic larval development in mountain environments.  Each of the 68 used characters were codified according to their primitive or derived represented stages, following criteria adopted in the recent literature, with the aim of using principles of numeric taxonomy to at temp the reconstruction of the phylogeny. The possibility that Geobatrachus could belong to the Microhyloidea due to its firmisternal condition, was easily discarded, and the absence of intercalary skeletal pieces in the digits, prevent also any possible close relationship with the Centrolenidae, Hylidae and Pseudidae, although there are no characters (except for the absence of an accessory tendon in the M. glutaeus magnus, regarded as a secondary loss that might exclude the inclusion of Geobatrachus in the Bufonoidea. No particular characters allow the inclusion of the genus either in the Myobatrachidae or the Heleophrynidae.  The absence of Bidder's organ (which is the only diagnostic difference between the Leptodactylidae and the Bufonidae eliminate the family Bufonidae from any further consideration, a conclusion that is supported also by experimental cladograms. Distinctive features such as the morphology of the pectoral girdle and the presence of dorsal osteoderms, characteristic of the Brachycephalidae (sensu McDIARMID, 1969 also exclude this family from consideration.   The combinational analysis made through cladograms confirms the presumptive derivation of the Phyllobatinae (= Dendrobatidae from the Elosiini, and leads to the conclusion that this group might be better regarded as a subfamily of the Leptodactylidae than as a family of their own. Although, in particular the firmisternal condition might suggest affinities of Geobatrachus with the Phyllobatinae, neither this genus or Rhinoderma can be referred to this subfamily. The analysis of the

  11. Complete mitochondrial genome of Nanorana pleskei (Amphibia: Anura: Dicroglossidae and evolutionary characteristics of the amphibian mitochondrial genomes

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    Guiying CHEN, Bin WANG, Jiongyu LIU, Feng XIE, Jianping JIANG

    2011-12-01

    Full Text Available The complete mitochondrial genome of Nanorana pleskei from the Qinghai-Tibet Plateau was sequenced. It includes 17,660 base pairs, containing 13 protein-coding genes, two rRNAs and 23 tRNAs. A tandem duplication of tRNAMet gene was found in this mitochondrial genome, and the similarity between the two tRNAMet genes is 85.8%, being the highest in amphibian mitochondrial genomes sequenced thus far. Based on gene organization, 24 types were found from 145 amphibian mitochondrial genomes. Type 1 was present in 108 species, type 11 in 11 species, types 5, 16, 17, and 20 each in two species, and the others each present in one species. Fifteen types were found in Anura, being the most diversity in three orders of the Lissamphibia. Our phylogenetic results using 11 protein-coding gene sequences of 145 amphibian mitochondrial genomes strongly support the monophyly of the Lissamphibia, as well as its three orders, the Gymnophiona, Caudata, and Anura, among which the relationships were ((Gymnophiona (Caudata, Anura. Based on the phylogenetic trees, type 1 was recognized as the ancestral type for amphibians, and type 11 was the synapomorphic type for the Neobatrachia. Gene rearrangements among lineages provide meaningful phylogenetic information. The rearrangement of the LTPF tRNA gene cluster and the translocation of the ND5 gene only found in the Neobatrachia support the monophyly of this group; similarly, the tandem duplication of the tRNAMet genes only found in the Dicroglossidae support the monophyly of this family [Current Zoology 57 (6: 785–805, 2011].

  12. Population genetics of the Chilean frog Batrachyla Leptopus (Leptodactylidae

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    J.R. Formas

    2000-03-01

    Full Text Available Electrophoretic variation of proteins encoded by 14 loci was analyzed in eight (five continental and three insular populations of the Chilean leptodactylid frog Batrachyla leptopus. The overall proportion of polymorphic loci was estimated to be 18.7% and the average number of alleles per locus, 1.2, while observed and expected heterozygosities were 1.7 and 5.1%, respectively. The estimated coefficient of genetic identity was 0.940; the corresponding figure for genetic distance was 0.063. F-statistics analysis showed a total inbreeding coefficient (Fit of 0.855 and high levels of genetic subdivision (Fst = 0.596 as well as of inbreeding within populations (Fis = 0.640. However, there was only a moderate level of genetic differentiation (Fst = 0.181 between the insular group of populations and the continental group.A variação eletroforética de proteínas codificadas por 14 loci foi analisada em oito populações (5 continentais e 3 insulares da rã leptodactilídea chilena Batrachyla leptopus. A proporção geral de loci polimórficos foi estimada como sendo de 18,7% e o número médio de alelos por loco, 1,2, enquanto que as heterozigosidades observada e esperada foram 1,7 e 5,1%, respectivamente. O coeficiente esperado de identidade genética foi 0,940; o número correspondente para a distância genética foi 0,063. A análise estatística F mostrou um coeficiente de endogamia total (Fit de 0,855 e altos níveis de subdivisão genética (Fst = 0,596, assim como de endogamia dentro das populações (Fis = 0,640. Contudo, houve apenas um nível moderado de diferenciação genética (Fst = 0,181 entre o grupo insular de populações e o grupo continental.

  13. Dinámica trófica de juveniles de Leptodactylus ocellatus (Anura: Leptodactylidae, en una isla del Paraná, Santa Fe, Argentina

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    Lajmanovich, Rafael Carlos

    1996-01-01

    Full Text Available Se analiza la dieta de juveniles de Leptodactylus ocellatus, la relación entre el tamaño predador-presa así como la variación de la dieta con el crecimiento. Se cuantificó el espectro trófico y se calculó la diversidad y amplitud trófica del nicho, tamaño e índice de importancia relativa de las presas. L ocellatus presenta una dieta generalista, integrada principalmente por insectos y arácnidos. Se halló una correlación positiva entre el tamaño de las ranas con el de las presas y se observó la existencia de un mayor consumo de presas terrestres en la clase de mayor tamaño. Is paper concerns the diet of juvenile Leptodactylus ocellatus, the predator-prey size relationships, and the changes in diet as the frogs grow. The trophic spectrum was quantified, and niche diversity and amplitude, prey size, and index of relative importance were calculated. Results show that L. ocellatus has a generalist diet, consisting mainly of insects and arachnids. A positive correlation between size frogs and prey was found, and a change of diet with increasing body size.

  14. Feeding habits of the frog Pleurodema diplolistris (Anura, Leptodactylidae in Quaternary sand dunes of the Middle Rio São Francisco, Bahia, Brazil

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    José Wellington Alves dos Santos

    2003-12-01

    Full Text Available In this work, we investigate the feeding habits of Pleurodema diplolistris, the most abundant anuran species of the São Francisco sand dunes, during a period of slightly over one year. The fieldwork was undertaken during four excursions to a sand dune in the semiarid Caatinga, Brazil, and the analyses were based on stomach contents. Pleurodema diplolistris were not active during the dry season. The important food categories in diet were Isoptera (winged forms, Coleoptera, and Formicidae. Small and large animals had different food comsumption patterns: small frogs showed positive electivity for termites and large frogs, for ants. The pattern was strongly influenced by large male food electivity. High levels of termite comsumption ocurred during the days of greater capture success. The pattern of high comsumption of termites detected here is different from that described in another study on lizards from the same locality and sampled in the same periods. We discuss alternative hypotheses that could explain the observed patterns.

  15. Revisión sobre la distribución geográfica de Physalaemus albifrons (Spix, 1824 (Anura: Leptodactylidae

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    Langone, José A.

    2001-09-01

    Full Text Available Existen con frecuencia en la literatura neotropical, confusiones respecto a la distribución geográfica de las especies de anuros. En el caso de las confusiones del género Physalaemus fueron y son debidas a identificaciones erradas, producto de descripciones originales vagas y del difícil acceso o inexistencia de material tipo. La presente nota trata sobre una de estas confusiones.

  16. INTRASPECIFIC VARIATION IN ACOUSTIC TRAITS AND BODY SIZE, AND NEW DISTRIBUTIONAL RECORDS FOR PSEUDOPALUDICOLA GIARETTAI CARVALHO, 2012 (ANURA, LEPTODACTYLIDAE, LEIUPERINAE: IMPLICATIONS FOR ITS CONGENERIC DIAGNOSIS

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    THIAGO RIBEIRO DE CARVALHO

    2015-01-01

    Full Text Available In this paper, we provide an updated diagnosis for Pseudopaludicola giarettai based on the morphometric and acoustic variation observed with the assessment of new populations, plus an expansion of its distribution range. Our results support that all acoustic variation observed might be attributed to intraspecific variation. The variation in body size and dorsal stripe patterns observed for Pseudopaludicola giarettai reinforces that the distinctive whistling advertisement call pattern is the most reliable evidence line to diagnose it from its congeners, whereas morphological (robust body, glandular dorsum and morphometric (body size features vary considerably within and among populations so that they should no longer be employed as diagnostic features of Pseudopaludicola giarettai.

  17. Three new species of the genus Adelophryne (Amphibia: Anura: Leptodactylidae) from northeastern Brazil, with remarks on the other species of the genus

    NARCIS (Netherlands)

    Hoogmoed, M.S.; Borges, D.M.; Cascon, P.

    1994-01-01

    In the present paper three new species of the genus Adelophryne from the coastal Atlantic forest in Brazil are described. The species are separated from the two species formerly known from the Amazon forest by caatinga vegetation and a distance of at least 1600 km. A. pachydactylus from Bahia has a

  18. Thaulin-1: The first antimicrobial peptide isolated from the skin of a Patagonian frog Pleurodema thaul (Anura: Leptodactylidae: Leiuperinae) with activity against Escherichia coli.

    Science.gov (United States)

    Marani, Mariela M; Perez, Luis O; de Araujo, Alyne Rodrigues; Plácido, Alexandra; Sousa, Carla F; Quelemes, Patrick Veras; Oliveira, Mayara; Gomes-Alves, Ana G; Pueta, Mariana; Gameiro, Paula; Tomás, Ana M; Delerue-Matos, Cristina; Eaton, Peter; Camperi, Silvia A; Basso, Néstor G; de Souza de Almeida Leite, Jose Roberto

    2017-03-20

    Patagonia's biodiversity has been explored from many points of view, however, skin secretions of native amphibians have not been evaluated for antimicrobial peptide research until now. In this sense, Pleurodema thaul is the first amphibian specie to be studied from this large region of South America. Analysis of cDNA-encoding peptide in skin samples allowed identification of four new antimicrobial peptides. The predicted mature peptides were synthesized and all of them showed weak or null antimicrobial activity against Klebsiella pneumoniae, Staphylococcus aureus and Escherichia coli with the exception of thaulin-1, a cationic 26-residue linear, amphipathic, Gly- and Leu-rich peptide with moderate antimicrobial activity against E. coli (MIC of 24.7μM). AFM and SPR studies suggested a preferential interaction between these peptides and bacterial membranes. Cytotoxicity assays showed that thaulin peptides had minimal effects at MIC concentrations towards human and animal cells. These are the first peptides described for amphibians of the Pleurodema genus. These findings highlight the potential of the Patagonian region's unexplored biodiversity as a source for new molecule discovery.

  19. Cytogenetic analyses of eight species in the genus Leptodactylus Fitzinger, 1843 (Amphibia, Anura, Leptodactylidae, including a new diploid number and a karyotype with multiple translocations

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    Gazoni Thiago

    2012-12-01

    Full Text Available Abstract Background The karyotypes of Leptodactylus species usually consist of 22 bi-armed chromosomes, but morphological variations in some chromosomes and even differences in the 2n have been reported. To better understand the mechanisms responsible for these differences, eight species were analysed using classical and molecular cytogenetic techniques, including replication banding with BrdU incorporation. Results Distinct chromosome numbers were found: 2n = 22 in Leptodactylus chaquensis, L. labyrinthicus, L. pentadactylus, L. petersii, L. podicipinus, and L. rhodomystax; 2n = 20 in Leptodactylus sp. (aff. podicipinus; and 2n = 24 in L. marmoratus. Among the species with 2n = 22, only three had the same basic karyotype. Leptodactylus pentadactylus presented multiple translocations, L. petersii displayed chromosome morphological discrepancy, and L. podicipinus had four pairs of telocentric chromosomes. Replication banding was crucial for characterising this variability and for explaining the reduced 2n in Leptodactylus sp. (aff. podicipinus. Leptodactylus marmoratus had few chromosomes with a similar banding patterns to the 2n = 22 karyotypes. The majority of the species presented a single NOR-bearing pair, which was confirmed using Ag-impregnation and FISH with an rDNA probe. In general, the NOR-bearing chromosomes corresponded to chromosome 8, but NORs were found on chromosome 3 or 4 in some species. Leptodactylus marmoratus had NORs on chromosome pairs 6 and 8. The data from C-banding, fluorochrome staining, and FISH using the telomeric probe helped in characterising the repetitive sequences. Even though hybridisation did occur on the chromosome ends, telomere-like repetitive sequences outside of the telomere region were identified. Metaphase I cells from L. pentadactylus confirmed its complex karyotype constitution because 12 chromosomes appeared as ring-shaped chain in addition to five bivalents. Conclusions Species of Leptodactylus exhibited both major and minor karyotypic differences which were identified by classical and molecular cytogenetic techniques. Replication banding, which is a unique procedure that has been used to obtain longitudinal multiple band patterns in amphibian chromosomes, allowed us to outline the general mechanisms responsible for these karyotype differences. The findings also suggested that L. marmoratus, which was formerly included in the genus Adenomera, may have undergone great chromosomal repatterning.

  20. Descrição da larva de Scinax similis (Cochran com notas comparativas sobre o grupo "ruber" no sudeste do Brasil (Amphibia, Anura, Hylidae Description of the larva of Scinax similis (Cochran with comparative notes on the Scinax ruber group in Southeastern Brazil (Amphibia, Anura, Hylidae

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    Ana C.R Alves

    1999-06-01

    Full Text Available The larva of Scinax similis (Cochran, 1952 is described from Ilha do Fundão (Rio de Janeiro, Rio de Janeiro State, Brazil. Comparisons with other species of the group that occur in Southeastern Brazil are added. The larva of S. similis can be distinguished by the following diagnostic features: (1 eyes large in relation to body length (17,3%, body height (26,8%, and body width (29,7%, interocular distance three times larger than eye diameter; (2 lower beak with two transverse stripes, proximal half white and distal half black.

  1. Seasonality, age structure and reproduction of Leptodactylus (Lithodytes lineatus (Anura, Leptodactylidae in Rondônia state, southwestern Amazon, Brazil Sazonalidade, estrutura etária e reprodução de Leptodactylus (Lithodytes lineatus (Anura, Leptodactylidae no estado de Rondônia, Brasil

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    Paulo Sérgio Bernarde

    2009-12-01

    Full Text Available Leptodactylus(Lithodytes lineatus (Schneider, 1799 is an Amazonian leaf litter frog considered rare or uncommon in several studies on anuran communities. Despite being a widely distributed frog in Amazonian forests, knowledge of the biology and ecology of this species is relatively scarce. This species has been reported to live in association with leaf-cutter ant nests (Atta spp. during the breeding period. In this paper we present data on the seasonality of this species and some reproductive information gathered at a locality of Rondônia state, northwestern Brazil. Field work was carried out between April 2001 and March 2002, with the use of pitfall traps with drift fences as a survey method. Leptodactylus (L. lineatus had a higher capture frequency in this locality compared to that of other studies carried out in other Amazonian localities, possibly because this species has secretive habits, such as calling and breeding from nests of leaf-cutting ants, and are difficult to find during visual encounter surveys. The breeding period occurs between October and March. Calling males and egg-bearing females were found between September and February and juvenile recruitment occurred mainly from the end of the rainy season to the beginning of the dry season (February to June. Males and females show sexual dimorphism in SVL, females being significantly larger than males. The number of ovarian eggs per female varies from 110 to 328 and analyses indicate that there is a significant correlation with SVL.Leptodactylus(Lithodytes lineatus (Schneider, 1799 é uma espécie de anuro amazônico considerado raro ou incomum em diversos estudos de comunidades de anfíbios. Embora apresente ampla distribuição na Floresta Amazônica, conhecimento sobre a sua biologia e ecologia são escassos. Esta espécie tem sido relatada por viver em associação com ninhos de formigas cortadeiras (Atta spp. durante o período reprodutivo. Neste trabalho, nós apresentamos dados de sazonalidade e reprodução desta espécie em uma localidade do estado de Rondônia, noroeste do Brasil. Trabalhos de campo foram conduzidos de abril de 2001 a março de 2002, com o uso de armadilhas de queda com rede direcionadora. Leptodactylus (L. lineatus teve uma alta taxa de captura nesta localidade, quando comparada com outros estudos em outras localidades na Amazônia, possivelmente devido a esta espécie possuir hábitos crípticos, como vocalizar e reproduzir dentro de ninhos de formigas, e ser dificilmente encontrada durante procura visual ativa. O período reprodutivo ocorre entre outubro e março. Machos vocalizando e fêmeas ovuladas foram encontrados entre setembro e janeiro e o recrutamento de juvenis ocorreu principalmente no final do período chuvoso. Machos e fêmeas apresentaram dimorfismo sexual quanto ao comprimento rostro-cloacal (CRC, sendo as fêmeas maiores que os machos. O número de folículos ovarianos por fêmea variou de 110 a 328 e análises indicaram que existe uma correlação significativa entre este número e o CRC.

  2. Skeletal development and adult osteology of Hypsiboas pulchellus (Anura: Hylidae

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    Julio M. Hoyos

    2012-07-01

    Full Text Available Osteological and skeletal characters have long been proven to be particularly informative in taxonomic and systematic research. Furthermore, ossification sequences are assumed to be a potential tool to investigate developmental states and developmental modes of fossil and extant skeletal specimens. Herein, we provide a detailed account on adult osteology and skeletogenesis in the Montevideo treefrog, Hypsiboas pulchellus (Anura: Hylidae based on evaluation of a series of cleared and stained specimens. A consensus sequence of ossification, i.e., the order of appearance of mineralized elements until early metamorphosis could be determined as (parasphenoid, presacral vertebrae I-VII, frontoparietal, exoccipital – transverse processes of presacral vertebrae I-VIII – sacral vertebra – (humerus, radioulna, ilium, femur, tibiofibula, scapula – (cleithrum, clavicle, coracoids, metacarpals, tarsals, metatarsals, phalanges, hypochord – (prootic, angulosplenial, dentary, maxilla, premaxilla, squamosal. Comparing the state of mineralized elements in individual specimens, a number of skeletal elements, including the exoccipital, frontoparietal, parasphenoid and prootic, as well as elements of the shoulder and pelvic girdles, and the phalanges, were found to vary intraspecifically regarding the relative time of their ossification within the ossification sequence.

  3. Complete mitochondrial genome of the Ye's spiny-vented frog Yerana yei (Anura: Dicroglossidae).

    Science.gov (United States)

    Chen, Zhuo; Zhai, Xiaofei; Zhu, Yanjun; Chen, Xiaohong

    2015-06-01

    Yerana yei (Anura: Dicroglossidae) is the only one species in the genus Yerana and the taxonomy of the Y. yei remains unresolved and controversial. The complete mitochondrial genome of Yerana yei (Anura: Dicroglossidae) was sequenced in the present study, and it is a circular molecule of 17,072 bp in length and contains the 38 genes typically found in other anurans: 13 protein-coding genes, 2 ribosomal RNA genes and 23 transfer RNA genes (including an extra copy of tRNA(Met)). The order and orientation of the genes is the same as that found in other Paini species. The A + T content of the overall base composition of H-strand is 58% (T, 29.4%; C, 27.3%; A, 28.6%; G, 14.7%) and the length of control region is 1580 bp with 67% A + T content.

  4. Vocalizações de Hyla werneri (Anura, Hylidae) no sul do Brasil

    OpenAIRE

    Bastos,Rogério P; Lorena D. Guimarães; Rodrigo Lingnau

    2004-01-01

    Vocalizations of Hyla werneri (Anura, Hylidae) in southern Brazil.Herein, we describe the vocal repertoire of Hyla werneri. We found four distinct vocalizations: advertisement call, aggressive call, distress call, and a mixed call. The advertisement call was the most frequent vocalization, with one to 23 notes. Aggressive calls had only one note, but with longer duration than notes of advertisement calls. One individual emitted four distress calls, and these showed a great variation. The mixe...

  5. [Early stages of development of Trypanosoma rotatorium (Mayer, 1843) from peripheral blood and internal organs of Anurans Bufo bufo (Linnaeus) and Rana sp. (Anura)].

    Science.gov (United States)

    Malysheva, M N

    2014-01-01

    The data on the fauna of trypanosomes of Anura of the Leningrad Province are given. The initial development stages of Trypanosoma rotatorium in peripheral blood and internal organs of the frog are described for the first time.

  6. Diversidade cariotípica e molecular de Leptodactylus (Anura, Leptodactylidae) e obtenção de sondas cromossomo-específicas de anfíbio por citometria de fluxo

    OpenAIRE

    Gazoni, Thiago [UNESP

    2015-01-01

    The genus Leptodactylus currently has 74 recognized species in the Neotropical Region, of which 57 were reported in Brazil. Factors such as high morphological similarity, as well as the lack of diverse data from different populations, result in the confusing taxonomic status of some species in the genus. Advances in this matter were obtained by increasing studies involving mainly comparison of molecular data, but often are not examined specimens collected in the type localities, fundamental f...

  7. Descripción de una nueva especie de Pseudopaludicola (Anura: Leptodactylidae, redescripción de P. falcipes (Hensel, 1867 y P. saltica (Cope, 1887 y osteología de las tres especies

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    Lobo, Fernando

    1994-01-01

    Full Text Available Se describe una nueva especie de Pseudopaludicola de la Sierra de Cipó, Minas Gerais, Brasil. También en este trabajo se redescriben P. falcipes (Hensel, 1867 y P. saltica (Cope, 1887. P. falcipes se redescribe en base a material topotípico y se designa un lectotipo para P . saltica (uno de los sintipos de Cope. 1887. Se presentan datos sobre la distribución y osteología de las tres especies estudiadas y los resultados se comparan con otras especies consideradas en un trabajo anterior (Lobo, en prensa. Al final se presenta una clave para la identificación de las especies del género. A new frog is described from the Serra do Cipó, Minas Gerais, Brazil. Pseudopaludicola falcipes (Hensel, 1867 aud P. saltica (Cope, 1887 are redescribed. P. falcipes is redescribed using topotype material. It is designated a lectotype for P. saltica. Data on the distribution and osteology of these species are presented and the results are comparisoned to another species studied previously (Lobo, in press. A key for the identification ofilie species of the genus is also provided.

  8. Inclusión de Physalaemus riograndensis Milstead, 1960 en la batracofauna de Misiones, Argentina, y otros aportes para el conocimiento de su distribución (Amphibia: Anura: Leptodactylidae

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    Chebez, Juan C.

    1995-01-01

    Full Text Available Physalaemus riograndensis Milstead, 1960. Rep. ARGENTINA, PROV.DE MISIONES, Dpto. Candelaria, Campo San Juan, 27° 25' S, 55° 40' W. 1 ejemplar. MACN número 34.646. Colector: E. Krauczuck.

  9. Diversidad trófica de dos especies sintópicas del género Leptodactylus (Anura: Leptodactylidae del sudeste de la provincia de Córdoba, Argentina

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    Cuevas, María Fernanda

    2007-04-01

    Full Text Available Se estudió la diversidad trófica de Leptodactylus gracilis y Leptodactylus latinasus del sudeste de la provincia de Córdoba, Argentina, con la finalidad de describir la composición de la dieta y determinar sus preferencias alimentarias según sexo y tamaño, y comparar la diversidad trófica entre las dos especies sintópicas que comparten el mismo tiempo y espacio. Los muestreos fueron quincenales, desde abril de 1998 hasta junio de 2000. Se determinó que estas especies se alimentaron principalmente de isópodos, arañas y hormigas, siendo los isópodos los que aportaron aproximadamente, la mitad del volumen ingerido. El Índice de Morisita- Horn y la Prueba de Chi-Cuadrado Test de Independencia, mostraron que no existen diferencias significativas entre la selección trófica dentro y entre las especies. Se puede concluir que existe entre estas dos especies un extremado solapamiento trófico tanto entre ellas como entre sexos y tamaños de la misma especie. We studied the trophic diversity of Leptodactylus gracilis and Leptodactylus latinasus from the southeast of Córdoba, Argentina. With the purpose of describing their composition, determining their preference according to sex and size, and comparing the trophic diversity between these two syntopic species that share the same space and time. Biweekly samplings were carried out from April 1998 to June 2000. We determined that these species fed mainly on isopods, spiders and ants (Formicidae, with the Isopoda representing almost 50% of the total volume ingested. The Index of Morisita-Horn and the Chi-Square Test of Independence showed that no significant differences exist in trophic selection either within or between the species. It is possible to conclude that there is considerable trophic overlapping between the two species as well as between sexes and sizes of the same species.

  10. Three new species of Eleutherodactylus (Amphibia: Leptodactylidae from high elevations of the cordillera Central of Colombia

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    Lynch John D.

    1996-11-01

    Full Text Available A new species of the Eleutherodactylus orcesi group, the smallest member of the group, is described from the Páramo de los Valles (Tolima. It is very similar to E. slmoterus. From the same locality, a new species of dwarf Eleutherodactylus, lacking a tympanum, is described. It appears to be a member of the E. myersi group. Lastly, a new large black Eleutherodactylusis described from páramo and subpáramo habitats of the Cordillera Central. This species is distributed from Antioquia to Cauca. With these three species, fifteen species of Eleutherodactylus are known for páramo and subpáramo habitats of the Cordillera Central north of the Macizo de Pasto. These 15 species be long to tour species groups.Se describe una especie nueva del grupo de Eleutherodactylus orcesi del Páramo de los Valles (Tolima. Esta especie es muy parecida a E. simoterus pero se distingue por su tamaño (la especie nueva es la más pequeña del grupo. Se describe también una especie enanita del Páramo de los Valles que posiblemente es una especie del grupo de Eleutherodactylus myersl. La especie es muy distinta porque carece de tímpano. Finalmente, se describe una especie grande y negra que se encuentra desde Antioquia hacia Cauca en la Cordillera Central. Con estas especies, tenemos 15 especies de Eleutherodactylus conocidas de los páramos y subpáramos de la Cordillera Central al norte del Macizo de Pasto, que pertenecen a cuatro grupos de especies.

  11. Osteological differentiation among Iberian Pelodytes (Anura, Pelodytidae

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    Sánchez-Herráiz, M. J.

    2002-12-01

    Full Text Available The morphological differentiation among Pelodytes species is analysed based on a sample of disarticulated bones from the main osteological regions of the male adult skeleton. A set of 35 interspecifically diagnostic characters, analysed under different outgroup hypotheses, clearly shows that P. ibericus and P. punctatus are a sister-group with respect to P. caucasicus. The Caucasian species retains a very primitive morphology, with only 17-23 % derived character-states, while both living Iberian species reach percentages of derivation over 68 %. There is little difference between P. ibericus and P. punctatus in their relative degree of evolutionary transformation, and when using P. caucasicus as the outgroup the percentage of derived character-states is 45 and 60 % respectively. Differentiation rates are calculated in darwin units for several characters, and we show that the skull components have higher rates than the traits directly related with locomotion. Several adult growth trajectories, different between species, are described and identified as diverse allometric heterochronies. Three factors have been detected that might have grouped several characters as coevolutionary units. These factors are: a an ontogenetic factor, operating through heterochronic processes, expressed as a tendency to reduce ossification; b a functional morphological integration, detected in the elements involved in skull size and proportions; and c an ecomorphological factor, presumably an adaptive response, can be assumed for characters related to limb shape.Se analiza la diferenciación morfológica en Pelodytes mediante el análisis comparado de una muestra de elementos óseos desarticulados procedentes de las principales regiones del esqueleto macho adulto. Un conjunto de 35 rasgos interespecíficamente diferenciales, analizada bajo diversos grupos externos, permite inferir que P. ibericus y P. punctatus forman un grupo hermano frente a P. caucasicus. La especie

  12. Organização celular dos testículos em Hylidae e Leptodactylidae, no Pantanal (Estado do Mato Grosso do Sul, Brasil - DOI: 10.4025/actascibiolsci.v31i4.3332 Cellular organization of the testes in Hylidae and Leptodactylidae, in the Pantanal (Mato Grosso do Sul State, Brazil - DOI: 10.4025/actascibiolsci.v31i4.3332

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    Ana Barbara dos Santos Rosa

    2009-08-01

    Full Text Available O objetivo deste trabalho foi analisar e comparar a organização das células germinativas em diferentes estádios de diferenciação celular nos machos adultos de Dendropsophus nanus (Boulenger, 1889, Pseudis limellum (Cope, 1862, Pseudis paradoxa (Linnaeus, 1758 e Scinax acuminatus (Cope, 1862, pertencentes à família Hylidae, e de Leptodactylus chaquensis (Cei, 1950 e L. podicipinus (Cope, 1862, pertencentes à família Leptodactylidae, coletados no Pantanal e na serra da Bodoquena, no Estado do Mato Grosso do Sul, Brasil. Os testículos foram retirados, fixados, desidratados em uma série alcoólica e incluídos em resina plástica do tipo methacrilato glicol (Historesin Leica®; cortados a 3 µm, corados com azul de toluidina 1% e observados no microscópio de luz. Constatou-se que os indivíduos da família Hylidae apresentam, em todas as épocas do ano, presença de todas as células de linhagem germinativa da espermatogênese. Já os indivíduos da família Leptodactylidae apresentam todas as células da linhagem germinativa somente no período chuvoso. As variações das características na organização dos epitélios seminíferos, assim como da evidente diferença na quantidade de espermatozoides no interior dos túbulos, demonstram que os anuros estudados apresentam diferentes formas de desenvolvimento da espermatogênese ao longo do ano: de forma cíclica para os da família Hylidae e acíclica, com liberação explosiva de espermatozoides, para os da família LeptodactylidaeThe objective of this work was to make a comparative analysis of germ cell organization at different stages of cellular differentiation in adult males of Dendropsophus nanus (Boulenger, 1889, Pseudis limellum (Cope, 1862, P. paradoxa (Linnaeus, 1758, and Scinax acuminatus (Cope, 1862, belonging to the family Hylidae; and Leptodactylus chaquensis (Cei, 1950 and L. podicipinus (Cope, 1862, belonging to the family Leptodactylidae, collected in the Pantanal and in

  13. Complete mitochondrial genomes of two brown frogs, Rana dybowskii and Rana cf. chensinensis (Anura: Ranidae).

    Science.gov (United States)

    Li, Jiao; Lei, Guangchun; Fu, Cuizhang

    2016-01-01

    We first determined complete mitochondrial genomes of Rana dybowskii and Rana cf. chensinensis (Anura: Ranidae). The mitogenomic lengths of R. dybowskii and R. cf. chensinensis were 18,864 and 18,808 bp, respectively. The two mitogenomes have similar gene compositions including 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and a control region. Rana dybowskii and R. cf. chensinensis mitogenomes displayed same gene order arrangements and similar base compositions with an A + T bias. Mitogenomic data of the two species contributed to provide molecular marker for their conservative genetics and clarified their phylogenetic position under mitogenome-based phylogeny of the genus Rana.

  14. Foleyellides rhinellae sp. nov. (Nematoda, Onchocercidae) a new filaria parasitizing Rhinella marina (Anura, Bufonidae) in Mexico.

    Science.gov (United States)

    García-Prieto, Luis; Ruiz-Torres, Nallely; Osorio-Sarabia, David; Merlo-Serna, Aldo

    2014-09-01

    A new nematode species, Foleyellides rhinellae sp. nov. (Onchocercidae), is described from specimens found in the body cavity of the cane toad, Rhinella marina (Linnaeus) (Anura, Bufonidae), in the Laguna de Coyuca, Guerrero, in the Pacific slope of Mexico. The new species differs from the other nine species of Foleyellides by infecting bufonid anurans and by the number and arrangement of caudal papillae. Other distinguishing feature of the new species is the size of the left spicule (0.16-0.23 long), the smallest recorded among the species included in the genus. Foleyellides rhinellae sp. nov. is the second known species of the genus recorded from amphibians of Mexico.

  15. Morphological comparison of five species of poison dart frogs of the genus Ranitomeya (Anura: Dendrobatidae) including the skeleton, the muscle system and inner organs

    Science.gov (United States)

    Krings, Markus; Klein, Benjamin; Heneka, Markus J.

    2017-01-01

    The morphology of larvae stages of most amphibians are often completely different than in adults. Tadpole descriptions have historically been based on external characters like morphometrics, color pattern and oral disc structure. Other papers described anatomical details by the use of dissections. The increase in micro-CT scanning technology provides an opportunity to quantify and describe in detail internal characters like skeleton, musculature and organs. To date, no such tadpole descriptions exist for the well-studied Neotropical poison dart frog genus Ranitomeya (Anura: Dendrobatidae). Here we provide descriptions of the internal skeletal, musculature and organ structures of five Ranitomeya species and then provide morphological comparisons. Contrary to previous observations, closely related species display several morphological differences. For example, we observed considerable variation in chondrocranial characters, the extent of cranial ossifications, the appearance of some cranial muscles and the arrangement of inner organs. Further studies on the tadpole morphology of more species of Ranitomeya and other dendrobatid genera are needed to enable us to understand the complete morphological variation in this group. PMID:28235032

  16. TREMATODOFAUNA COMPLEXULUI PELOPHYLAX ESCULENTA (AMPHIBIA, ANURA DIN CODRII CENTRALI AI REPUBLICII MOLDOVA. 1. FAMILIILE PLAGIORCHIIDAE, CEPHALOGONIMIDAE

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    Dumitru ERHAN

    2015-12-01

    Full Text Available Lucrarea conţine date cu privire la infestarea cu trematode a amfibienilor din familia Ranidae (Amphibia, Anura care populează ecosistemele naturale şi antropizate ale Codrilor centrali din Republica Moldova. Cercetări helmintologice ale amfibienilor au fost efectuate pentru prima dată în Republica Moldova. Rezultatele obţinute atestă infestarea ranidelor verzi (Rana ridibunda, R. lessonae, R. esculenta cu trematode din familiile Gorgoderidae (Gorgodera varsoviensis Sinitzin, 1905, Diplodiscidae (Diplodiscus subclavatus Pallas, 1760, Plagiorchiidae (Opisthioglyphe ranae Frohlich, 1791, Haematoloechus variegatus Rudolphi, 1819, Cephalogonimidae (Cephalogonimus retusus Dujardin, 1845 şi Lecithodendriidae (Pleurogenes claviger Rudolphi, 1819, Pleurogenoides medians,Olsson, 1876, Prosotocus confusus Looss, 1894, Candidotrema loossi, Africa, 1930. În lucrare sunt expuse rezultatele ce atestă nivelul de infestare a complexului Pelophylax esculenta cu specii de trematode din familiile Plagiorchiidae şi Cephalogonimidae. Pentru fiecare specie au fost stabilite: încadrarea sistema-tică, sinonimele, gazdele, localizarea organică, răspândirea geografică, etiologia şi ciclul biologic. De asemenea, este specificat volumul materialului colectat, este dată descrierea morfologică a speciilor, indicat nivelul de infestare în funcţie de vârstă, gen şi ecosistem, acestea fiind însoţite de fotografii şi figuri originale. FAUNA OF TREMATODES OF COMPLEX PELOPHYLAX ESCULENTA (AMPHIBIA, ANURA FROM CENTRAL CODRI FOREST OF THE REPUBLIC OF MOLDOVA. 1. FAMILIES PLAGIORCHIIDAE, CEPHALOGONIMIDAEThe paper presents data on trematodes infestation in amphibians from family Ranidae (Amphibia, Anura in natural and anthropized ecosystems of Central Codri forest from the Republic of Moldova. The helminthological researches of amphibians were accomplished for the first time in the Republic of Moldova. As result the infestation of Ranidae family species

  17. A new species of Andean frog of the genus Bryophryne from southern Peru Anura: Craugastoridae) and its phylogenetic position, with notes on the diversity of the genus.

    Science.gov (United States)

    Chaparro, Juan C; Padial, José M; Gutiérrez, Roberto C; De La Riva, Ignacio

    2015-07-30

    We describe a new species of terrestrial frog of the genus Bryophryne (Anura: Craugastoridae) from the wet puna and elfin forests of the Amazonian versant of the Andes. The new species seems to be restricted to high altitude environments at elevations between 3506-3651 m in the area now protected by Megantoni National Sanctuary and Manu National Park (Distrito de Echarate, Provincia La Convención, Departamento Cusco, Peru). The new species is characterized by lacking vomerine processes of vomers, by having tympanic annulus and tympanic membrane not evident through the skin, smooth dorsal skin with scattered warts, conspicuous dorsolateral, middorsal, and occipital folds, warty flanks, areolate skin on ventral surfaces of the body, and by lacking finger and toe fringes and basal web on feet. In life, specimens have bright and highly variable dorsal coloration that ranges from olive-green to red with variable combinations of red or orange marks (red or orange in the green form and olive-green in the red form). Molecular phylogenetic analyses of mitochondrial and nuclear DNA place the new species within the genus Bryophryne and as sister group of B. cophites. Bryophryne bustamantei, also sequenced for this study, is found as the sister group of the clade formed by B. cophites and the new species. Bryophryne is found as sister group of Psychrophrynella in maximum likelihood analyses and as the sister group of a large clade of holoadenines in parsimony analyses. The genus Bryophryne now contains nine species, all of them distributed along the Cordillera Oriental of the Peruvian Andes, southeast of the Apurimac River valley.

  18. A new species of Megophrys (Amphibia: Anura: Megophry-idae from the northwestern Hunan Province, China

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    Xiaoyang MO, Youhui SHEN, Honghui LI, Xiushan WU

    2010-08-01

    Full Text Available A new species of Megophrys (Amphibia: Anura: Megophryidae, Megophrys tuberogranulatus Shen, Mo et Li, sp. nov. (Holotype HNUL 03080902, adult male, SVL: 38.2 mm, from Sangzhi County, Hunan Province, is described. Megophrys tuberogranulatus is closely related to both Megophrys kuatunensis and Megophrys minor. Characters of the new species that differentiate this species from close relatives are skin granulated with big tubercles on the dorsal sides of both thigh and tibia, the bigger inner metacarpal tubercle, upper eyelid wider than the interorbital space, hind limbs longer, overlapping of the left and right calcaneal parts. The type specimens are deposited in the Animal Museum of Life Sciences College of Hunan Normal University [Current Zoology 56 (4: 432–436, 2010].

  19. Complete mitochondrial genome of the green odorous frog Odorrana margaretae (Anura: Ranidae).

    Science.gov (United States)

    Chen, Zhuo; Zhang, Jie; Zhai, Xiaofei; Zhu, Yanjun; Chen, Xiaohong

    2015-06-01

    The complete mitochondrial genome (mitogenome) of the green odorous frog Odorrana margaretae (Anura: Ranidae) has been studied. The 17,903 bp circular genome contains the typical complement of 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and a control region. The AT content of the overall base compositon of H-strand is 56% and the length of control region is 2501 bp with 63.8% AT content. The arrangement of the protein-coding and ribosomal RNA genes was the same as that found in other anurans. The cluster of rearranged LTPF tRNA genes and the translocation of tRNA(His) gene into the D-loop region are observed.

  20. Phylogeography of the fanged dicroglossine frog, Limnonectes fujianensis (Anura, Ranidae), in Taiwan.

    Science.gov (United States)

    Jang-Liaw, Nian-Hong; Chou, Wen-Hao

    2011-04-01

    A phylogenetic analysis of Taiwanese fanged dicroglossine frog, Limnonectes fujianensis (Anura, Ranidae), was conducted to examine its genetic diversification using sequence data from a portion of the mitochondrial DNA (mtDNA) cytochrome b sequences. We collected genetic data from 200 individuals at 23 localities in Taiwan and three localities in China. A neighbor-joining tree of 39 haplotypes revealed two clades in Taiwan and a clade in China, each showing restricted geographical distribution. The pattern of geographical divergence suggests a single invasion into Taiwan. Divergence times between clades were inferred using molecular clock tests. The population relationship of L. fujianensis between Taiwan and mainland China, and the phylogenetic relationships with its congeners, e.g., L. bannaensis, L. fragilis and L. kuhlii, were obtained and discussed.

  1. Vocalizações de Hyla werneri (Anura, Hylidae no sul do Brasil

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    Rogério P. Bastos

    2004-12-01

    Full Text Available Vocalizations of Hyla werneri (Anura, Hylidae in southern Brazil.Herein, we describe the vocal repertoire of Hyla werneri. We found four distinct vocalizations: advertisement call, aggressive call, distress call, and a mixed call. The advertisement call was the most frequent vocalization, with one to 23 notes. Aggressive calls had only one note, but with longer duration than notes of advertisement calls. One individual emitted four distress calls, and these showed a great variation. The mixed calls are formed by the emission of an aggressive call followed by five to 23 notes similar to theadvertisement call, probably a strategy to partition the attractive and aggressive functions in different notes on the same call. We suggest that the mixed calls of H. werneri could be a graded aggressive call system, already found in other anurans, which allows males to gradually reduce the number of attractive elements whileincreasing the aggressiveness of the call.

  2. The King of the Dwarves: a new cryptic species of Dainty Frog (Anura: Pyxicephalidae: Cacosternum) from the eastern Great Escarpment of South Africa.

    Science.gov (United States)

    Conradie, Werner

    2014-04-04

    Phylogenetic reconstruction using the mitochondrial 16S marker shows the presence of a cryptic species of Cacosternum (Anura: Pyxicephalidae) from the eastern Great Escarpment of South Africa, supporting the Greater Maputaland-Pondoland-Albany region of vertebrate endemism. Bioacoustic and morphological characteristics, in conjunction with colouration differences, allow the description of this cryptic species. Tadpoles and details of life history are described.

  3. A new species of broad-headed eleutherodactylus from the cordillera occidental of Colombia (Amphibia, Leptodactylidae A new species of Broad-Headed Eleutherodactylus from the Cordillera Occidental of Colombia (Amphibia, Leptodactylidae

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    Lynch John D.

    1986-12-01

    Full Text Available The broad-headed eleutherodactyline frogs have been studied by Lynch(1975, 1981. Although frogs of this assembly are easily identified (Lynch,1975, 1976, 1981, the assembly is not a natural group (Lynch, 1986.Recently, Rivero (1984 described a new species, E. sernai, from westernAntioquia, Colombia. Although Rivero associated E. sernai with thebiporcatus group, the species appears to be a member of the sulcatus group(because it possesses the plesiornorphic condition of the mandibular musclesadductors and the trigeminal nerve mandibular ramus. However, this characteristicis not sufficient to place E. sernai within the sulcatus group; theassignment will be defended in a future paper on the osteology of the variousspecies of the group. For the moment, the sulcatus group contains thefollowing species: E. cerasies Lynch, E. cornutus (Jimenez de la Espada,E. helonotus (Lynch, E. ingeri (Cochran and Gain, E. ruizi Lynch, E.sernai Rivero, and E. sulcatus Se describe Eleutherodactylus cadenai sp. nov. de las selvas de la vertiente occidental de la Cordillera Occidental de Colombia (corregimiento .de Murrí, Municipio de Frontino, Antioquia.  La especie parece tener un ancestro común con Eleutherodactylus ingeri de los bosques nublados de la Cordillera Oriental de Colombia y las dos tienen parentescos con Eleutherodactylus ruizi de las cordilleras Central y Occidental de Colombia.

  4. Osteología, taxonomía y relaciones filogenéticas de las ranas del género Telmatobufo (Leptodactylidae Osteology, taxonomy and phylogenetic relationships of the frog genus Telmatobufo (Leptodactylidae

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    J. RAMÓN FORMAS

    2001-06-01

    distance and Rogers' genetic distance were employed to assess the morphological and the genetical similarities among the three Telmatobufo species. Employing mtRNA12S sequences, in combination with polarized allelic frequencies of structural genes, and morphological (external and osteological characters, a hypothesis on the phylogenetic relationships of the Telmatobufo species is proposed, worked on principles of maximum parsimony and maximum likelihood. Finally, a reconstruction of the evolutionary history and speciation process of this group of endemic frogs of the temperate central southern Chilean forests is proposed

  5. Reprodução de Pseudis minuta (Anura, Hylidae no sul do Brasil

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    Janaine Melchiors

    2004-09-01

    Full Text Available Reproduction of Pseudis minuta (Anura, Hylidae in southern Brazil.This study was based on individuals of Pseudis minuta captured or observed in the municipality of Candiota, Campanha region of the state of Rio Grande do Sul, southern Brazil. Sampling occurred along ten non-consecutive months in 2000, 2001 and 2002. The reproductive phases were characterized based on the gonadal development stage of39 males and 50 females, and on the observation, in nature, of the seasonal distribution of calling males, occurrence of amplectant pairs, and presence of larvae, juveniles and adults. Calls were recorded from August to April, amplectant pairs from October to February (except January, tadpoles from October to March (except February, and juveniles in all the sampled months (except January. Reproductive activity was not observed in late fall and early winter, even though females with post-vitellogenic oocytes and males with spermatozoa in the seminiferous tubules were recorded in allthe seasons. Mature females were statistically larger and heavier than mature males.The smallest female with post-vitellogenic oocytes had 32.0 mm of snout-vent length,and the smallest male with spermatozoa in its seminiferous tubules had 20.6 mm. The number of post-vitellogenic oocytes was directly proportional to the mass and to the snout-vent length of females, and the length of testis was directly proportional to the snout-vent length and to the mass of males.

  6. Variability of Structural and Biomechanical Parameters of Pelophylax Esculentus (Amphibia, Anura Limb Bones

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    Broshko Ye. O.

    2014-07-01

    Full Text Available Variability of Structural and Biomechanical Prameters of Pelophylax esculentus (Amphibia, Anura Limb Bones. Broshko Ye. O. — Structural and biomechanical parameters of Edible Frog, Pelophylax esculentus (Linnaeus, 1758, limb bones, namely, mass, linear dimensions, parameters of the shaft’s cross-sectional shape (cross-sectional area, moments of inertia, radiuses of inertia were investigated. Some coefficients were also estimated: diameters ratio (df/ds, cross-sectional index (ik, principal moments of inertia ratio (Imax/Imin.. Coefficients of variation of linear dimensions (11.9-20.0 % anrelative bone mass (22-35 % were established. Moments of inertia of various bones are more variable (CV = 41.67-56.35 % in relation to radii of inertia (CV = 9.68-14.67 %. Shaft’s cross-sectional shape is invariable in all cases. However, there is high individual variability of structural and biomechanical parameters of P. esculentus limb bones. Variability of parameters was limited by the certain range. We suggest the presence of stable norm in bone structure. Stylopodium bones have the primary biomechanical function among the elements of limb skeleton, because their parameters most clearly responsive to changes in body mass.

  7. Phylogeny and biogeography of South Chinese brown frogs (Ranidae, Anura).

    Science.gov (United States)

    Zhou, Yu; Wang, Sirui; Zhu, Hedan; Li, Pipeng; Yang, Baotian; Ma, Jianzhang

    2017-01-01

    Few studies have explored the role of Cenozoic tectonic evolution in shaping the patterns and processes of extant animal distributions in and around East Asia. In this study, we selected South Chinese brown frogs as a model to examine the phylogenetic and biogeographical consequences of Miocene tectonic events within South China and its margins. We used mitochondrial and nuclear molecular data to reconstruct phylogenetic interrelationships among Chinese brown frogs using Bayesian and maximum likelihood analyses. The phylogeny results show that there are four main clades of Chinese brown frogs. Excepting the three commonly known Chinese brown frog species groups, R. maoershanensis forms an independent clade nearest to the R. japonica group. Phylogeny and P-distance analyses confirmed R. maoershanensis as a valid species. Among South Chinese brown frogs, there are four subclades associated with four geographical areas: (I) R. maoershanensis; (II) R. japonica; (III) R. chaochiaoensis; and (IV) other species of the R. longicrus species group. Divergence times, estimated using mitochondrial sequences, place the vicariance events among the four subclades in the middle to late Miocene epoch. Our results suggest that (1) South Chinese brown frogs originated due to a vicariance event separating them from the R. chensinensis species group at the time of the Geological movement (~18 million years ago, Ma) in southern Tibet and the Himalayan region; (2) the separation and speciation of R. maoershanensis from the R. japonica group occurred due to the dry climate at approximately 16 Ma; (3) South Chinese brown frogs migrated from South China to Japan at the time (~10.8 Ma) that the global sea-level fell and the East China Sea Shelf Basin was swamp facies, when a land gallery may have formed across the sea to connect the two areas; and (4) R. chaochiaoensis separated from other species of the R. longicrus species group during the uplift of the Tibetan Plateau at approximately 9

  8. Osteological differentiation among Iberian Pelodytes (Anura, Pelodytidae)

    OpenAIRE

    2002-01-01

    The morphological differentiation among Pelodytes species is analysed based on a sample of disarticulated bones from the main osteological regions of the male adult skeleton. A set of 35 interspecifically diagnostic characters, analysed under different outgroup hypotheses, clearly shows that P. ibericus and P. punctatus are a sister-group with respect to P. caucasicus. The Caucasian species retains a very primitive morphology, with only 17-23 % derived character-states, while both living Iber...

  9. The advertisement call of Ameerega pulchripecta (Silverstone, 1976)(Anura, Dendrobatidae).

    Science.gov (United States)

    Costa-Campos, Carlos Eduardo; Lima, Albertina Pimentel; Amézquita, Adolfo

    2016-07-06

    The name Ameerega picta was once used to denote a lineage of poison frogs (Dendrobatidae) distributed throughout most of the Amazon basin (Silverstone 1976); more recently, to describe a phenetic group involving at least 18 species, Lötters et al. (2007) pointed out that some of the lineages were indeed derived from the former A. picta. Among them, the nominal species with the widest distribution is A. hahneli (Haddad & Martins 1994; Twomey & Brown 2008), also an alleged complex of poorly defined species (Grant et al. 2006; Fouquet et al. 2007; Roberts et al. 2007). The mate-recognition signal, the advertisement call, was part of the evidence used to revalidate A. hahneli as a different species from A. picta. Although the advertisement call has been described for one or few individuals of other species in the group (Haddad & Martins 1994; Costa et al. 2006; Twomey & Brown 2008; Lötters et al. 2009), namely A. flavopicta, A. braccata and A. boehmei, and A. hahneli, we still lack a formal description for A. pulchripecta, the sister taxon of A. hahneli (Twomey & Brown 2008). Its call has been qualitatively described as similar to A. hahneli's call, but "deeper-voiced" (Lötters et al. 2007).

  10. Vocal sac development and accelerated sexual maturity in the lesser swimming frog, Pseudis minuta (Anura, Hylidae).

    Science.gov (United States)

    Goldberg, Javier; Barrasso, Diego A; Agostini, M Gabriela; Quinzio, Silvia

    2016-12-01

    Sexual maturity involves the differentiation of the reproductive system, the maturation of germ cells, and the development of secondary sexual characteristics. Even though this topic has received much attention, little is known about the sequence of events that encompass reproductive maturation in anurans and what it could reveal about the developmental basis of life cycle evolution. The discovery of froglets of Pseudis minuta with incipient vocal sacs calling in breeding pools alongside several larger adult specimens with fully developed vocal sacs raised the question of the timing of sexual maturity in this species. Here we describe the sequence and timing of differentiation, development and maturation of the vocal sac apparatus and the testes in P. minuta (Anura, Hylidae), in order to establish a timeline of events leading to sexual maturity. Differentiation of the vocal sac apparatus begins at the final metamorphic stages, earlier than reported for other species, and the vocal sac acquires its final shape during the early postmetamorphic period. These modifications occur after gonadal differentiation, which begins early during the larval period and proceeds with a highly accelerated rate of development (e.g., secondary spermatids appear well before metamorphic climax), a situation reported previously for other anuran species only in the genus Pseudis. These results, together with a skeletochronological analysis showing that some calling specimens presented no lines of arrested growth, indicate acceleration in the timing of sexual maturity in Pseudis, and raise questions about the interdependence/decoupling during the development of the different components involved in reaching the adult stage. Copyright © 2016 Elsevier GmbH. All rights reserved.

  11. A new minute Andean Pristimantis (Anura: Strabomantidae from Venezuela

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    César L. Barrio-Amorós

    2012-12-01

    Full Text Available A new species of Pristimantis is described from the Venezuelan Andes. The new species is the smallest in its genus known in Venezuela and belongs to the Pristimantis unistrigatus Group. It differs from the rest of Venezuelan Andean congeners in body size (mean male SVL < 21.3 mm, female SVL < 26.3 mm, expanded discs on fingers and toes, absence of dorsolateral folds, and a distinctivecall consisting in 2–5 cricket-like short notes. The new species inhabits the southwestern part of the Cordillera de Mérida in Venezuela and the Venezuelan side of the Cordillera Oriental deColombia, and could be present on the Colombian portion of the cordillera as well.

  12. Miología pectoral de algunos Centrolenidae (Amphibia: Anura

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    Manzano, Adriana S.

    1999-11-01

    Full Text Available El estudio comparativo de la miología pectoral en dos géneros de Centrolenidae (Centrolene e Hyalinobatrachium que incluyen a cuatro especies (C. geckoideum, C. grandisonae, C. robledal y H. aureoguttatum, brinda una visión más completa de la morfología de la cintura pectoral en los anuros, ampliando la información disponible. Este estudio incorpora caracteres nuevos para el tratado de la familia, antecedente de importancia ya que los caracteres frecuentemente utilizados para definir al grupo son homoplásicos (Lynch, 1973; Duellman & Trueb, 1986; Ford & Cannatella, 1993 y ponen en duda la monofilia del grupo. Los resultados muestran la escasa variabilidad de la musculatura pectoral en los géneros de Centrolenidae. Al mismo tiempo resaltan variaciones con el género Hyalinobatrachium en relación con los músculos depressor mandibulae y pectoralis abdominalis. En general existe una tendencia a la duplicación de algunos músculos como el serratus inferioris, dorsal scapulae y depressor mandibulae (característica observada también en Hylidae; Manzano, 1996. The comparative study of pectoral myology in two genera of Centrolenidae (Centrolene and Hyalinobatrachium, including four species (C. geckoideum, C. grandisonae, C. robledoi y H. aureoguttatum, adds to our understanding of the pectoral girdle morphology of anurans, enlarging the available information. This study examines new characters for the family. Study of new characters is important because the most frequently used characters to define the group are homoplastic (Lynch, 1973; Duellman & Trueb, 1986; Ford & Cannatella, 1993 which produces a dubious monophyly of group. The results of this study show us the little variability of the pectoral musculature in Centrolenid genera. At the same time some variations between Centrolene and Hyalinobatrachium (related to the depressor mandibulae and pectoralis abdominalis muscles, are significant. In addition, a tendency to duplicate some

  13. [Bioacoustic of the advertisement call of Ceratophrys cranwelli (Anura: Ceratophryidae)].

    Science.gov (United States)

    Valetti, Julián Alonso; Salas, Nancy Edith; Martino, Adolfo Ludovico

    2013-03-01

    The advertisement call plays an important role in the life history of anuran amphibians, mainly during the breeding season. Call features represent an important character to discriminate species, and sound emissions are very effective to assure or reinforce genetic incompatibility, especially in the case of sibling species. Since frogs are ectotherms, acoustic properties of their calls will vary with temperature. In this study, we described the advertisement call of C. cranwelli, quantifying the temperature effect on its components. The acoustic emissions were recorded during 2007 using a DAT record Sony TCD-100 with stereo microphone ECM-MS907 Sony and tape TDK DAT-RGX 60. As males emit their calls floating in temporary ponds, water temperatures were registered after recording the advertisement calls with a digital thermometer TES 1300+/-0.1 degreeC. Altogether, 54 calls from 18 males were analyzed. The temporal variables of each advertisement call were measured using oscillograms and sonograms and the analyses of dominant frequency were performed using a spectrogram. Multiple correlation analysis was used to identify the temperature-dependent acoustic variables and the temperature effect on these variables was quantified using linear regression models. The advertisement call of C. cranwelli consists of a single pulse group. Call duration, Pulse duration and Pulse interval decreased with the temperature, whereas the Pulse rate increased with temperature. The temperature-dependent variables were standardized at 25 degreeC according to the linear regression model obtained. The acoustic variables that were correlated with the temperature are the variables which emissions depend on laryngeal muscles and the temperature constraints the contractile properties of muscles. Our results indicated that temperature explains an important fraction of the variability in some acoustic variables (79% in the Pulse rate), and demonstrated the importance of considering the effect of

  14. A new species of Melanophryniscus (Anura, Bufonidae from Uruguay Una nueva especie de Melanophryniscus (Anura, Bufonidae del Uruguay

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    Raúl Maneyro

    2008-06-01

    Full Text Available A new species of bufonid toad of the genus Melanophryniscus from northern Uruguay is described. It is included in the M. moreirae group and its external morphology is similar to Melanophryniscus sanmartini. Melanophryniscus sp. nov. is distinguished by having a light brown dorsal coloration with six darker longitudinal glandular ridges on the dorsal surface of the body and the gular region uniformly black.Se describe una nueva especie de anuro bufónido del género Melanophryniscus, procedente del norte de Uruguay. La nueva especie se incluye en el grupo M. moreirae y es similar, en cuanto a su morfología externa, con Melanophryniscus sanmartini. Melanophryniscus sp. nov. se distingue por presentar una coloración dorsal castaño clara con seis cordones glandulares longitudinales más oscuros en la superficie dorsal del cuerpo y la región gular de color negro uniforme.

  15. Redescrição de Ischnocnema holti (Amphibia: Anura: Brachycephalidae Redescription of Ischnocnema holti (Amphibia, Anura

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    Mariane Targino

    2008-12-01

    Full Text Available Ischnocnema holti (Cochran, 1948 foi descrito com base em apenas um único indivíduo coletado no início do século XX no alto da Serra do Itatiaia. Neste trabalho é apresentada uma redescrição dessa espécie, baseada em 25 exemplares (18 machos e sete fêmeas, coletados na localidade-tipo. Medições dos exemplares, descrição da coloração em vida e aspectos de sua biologia e reprodução, observados em campo são incluídos. Ischnocnema holti é uma espécie de porte médio (comprimento rostro-anal: 13,5 a 31,7mm, vista dorsal e lateral arredondada e discos adesivos dos dedos bem desenvolvidos, e muita plasticidade em relação a sua morfologia e coloração. Encontra-se no grupo de I. lactea (Miranda-Ribeiro, 1923 e é aqui comparada com alguns de seus componentes.Ischnocnema holti (Cochran, 1948 was described based on a single specimen collected in the beginning of 20th century at the Itatiaia mountain range. In this study, we present a redescription of the species based on 25 specimens (18 males and seven females collected at the type locality. Measurements of the specimens, description of its color pattern in life, as well as aspects of its biology and reproduction are presented. Ischnocnema holti is a medium-sized species (snout-vent length from 13.5 to 31.7mm, snout shape rounded in dorsal and lateral views and digital discs well developed. Ischnocnema holti presents considerable plasticity in its morphology and coloration. This study includes I. holti in the I. lactea (Miranda-Ribeiro, 1923 group and compares it with some of its components.

  16. Boletín de la AHA | Volumen 2 | Número 1-3

    OpenAIRE

    Asociación Herpetológica Argentina (AHA)

    1985-01-01

    - Resúmenes de los trabajos presentados en la II Reunión de Comunicaciones Herpetológicas: -- Un nuevo anfibio para la provincia de Mendoza (Argentina): Ceratophrys cranwelli Barrio (Anura, Leptodactylidae); Enrique Richard -- El cariotipo de Amphisbaena munoai y comentarios sobre la meiosis en los Amphisbaenidae; Gabriel Skuk -- Histología del tracto digestivo de Lilaemus multimaculatus (Dumeril y Bibron, 1837); Viviana C. Devincenti, Lía Goldemberg y José M. Chani -- Estudio...

  17. Diets of tadpoles from a temporary pond in southeastern Brazil (Amphibia, Anura

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    Denise de C. Rossa-Feres

    2004-12-01

    Full Text Available The diet of tadpoles of 13 anuran species was determined to verify whether food resource partitioning occurs and whether the degree of diet similarity is related to taxonomic affinity. Tadpoles of all species studied were mainly herbivorous, except for these of Leptodactylus fuscus (Schneider, 1799 which were mycophagous. Although some species had exclusive items in their diet, most tadpole species ingested the same items, but differed in the amount of each item consumed. Two guilds were found: tadpoles that feed on diatoms on the pond bottom, and tadpoles that feed on Oedogonium Link, 1820 algae in midwater. Diet similarity was related to the taxonomic relationship, microhabitat and feeding behavior of tadpoles indicating that the community organization is complex and resulting from the interaction of several parameters.Dieta dos girinos de um açude temporário no sudeste do Brasil (Amphibia, Anura. Determinou-se a dieta dos girinos de 13 espécies de anuros, com o objetivo de verificar se ocorre partilha de recursos alimentares e se o grau de similaridade na dieta é relacionado ao parentesco, inferido pela proximidade taxonômica. Os girinos de todas as espécies estudadas foram preponderantemente herbívoros, exceto os de Leptodactylus fuscus (Schneider, 1799 que foram micófagos. Embora algumas espécies tenham apresentado itens exclusivos em sua dieta, os girinos da maioria das espécies ingeriram os mesmos itens, diferindo na quantidade consumida de cada item. Duas guildas foram encontradas: girinos que se alimentam de diatomáceas no fundo do corpo d'água e girinos que se alimentam de algas do gênero Oedogonium Link, 1820 à meia-água. A similaridade na dieta foi relacionada à proximidade taxonômica, ao microhabitat e ao comportamento de alimentação, indicando que a organização desta comunidade é complexa e resultante da interação entre vários fatores.

  18. Ochoterenella esslingeri n. sp. (Nematoda: Onchocercidae: Waltonellinae) from Bokermannohyla luctuosa (Anura: Hylidae) in Minas Gerais, Brazil, with notes on Paraochoterenella Purnomo & Bangs, 1999

    Science.gov (United States)

    Souza Lima, S.; Marun, B.; Alves, P.V.; Bain, O.

    2012-01-01

    The waltonelline Ochoterenella esslingeri n. sp., a filarial parasite of the anuran Bokermannohyla luctuosa in Minas Gerais, Brazil is described. Several characters distinguish this new species from the 15 species presently included in the genus: the cuticular ornamentation of the female that is restricted to the posterior region of the body, the irregular arrangement of the small, rounded bosses, the postoesophageal vulva, the short glandular oesophagus, the size and shape of the microfilariae, the long left spicule and high spicular ratio. Irregularly arranged, tiny, rounded bosses are common in the monotypic genus Paraochoterenella from an Indonesian ranid, which is not well defined but likely valid. In the Neotropical Realm, the type hosts of the species of Ochoterenella are Hylidae (O. esslingeri n. sp.), Leptodactylidae (two species) and the remaining 13 species were described from the giant toad Rhinella marina (Bufonidae). PMID:23193518

  19. Distribution and Ecology of the Western Ecuador Frog Leptodactylus labrosus (Amphibia: Anura: Leptodactylidae)%厄瓜多尔西部新热带蛙(两栖纲: 无尾目:细趾蟾科)的分布特征及生态习性

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Leptodactylus labrosus is a terrestrial sit-and-wait predator; its diet includes ground-level, fossorial, and flying insects, and ants numerically predominate. Bothrops asper is recorded as a predator of L. labrosus. L. labrosus lives mainly in deciduous and semi-deciduous forests, where it is restricted to wet microhabitats, and occasionally in evergreen forests. L. labrosus inhabits northern, central, and southern regions of western coastal Ecuador and northern and central western coastal Peru up to 700 m, and into the dry interandean valleys of southern Ecuador and northern Peru up to 1 300 m. Its distribution encompasses moistly seasonally dry forest in coastal Ecuador and Peru. It also occupies moister areas towards the slopes of the Andes where it is sympatric with three other congeneric species, but at sites of sympatry the species show habitat segregation. The distribution pattern of L. labrosus is shared by several other range-restricted amphibians corresponding to the Tumbesian region, which should be recognized as an endemic Amphibian area. The zone between the Choco and Tumbesian regions, where L. labrosus gets in sympatry with other Leptodactylus species, possess ecological and climatic characteristics that have shaped a unique fauna, including several endemic taxa; and it should be recognized as the west Ecuadorian endemic region.%Leptodactylus labrosus属于陆地坐-等型的捕食者, 其食物包括地表的、掘地的及飞行昆虫, 其中蚂蚁数量最多. 曾有报道Bothrops asper是其天敌. L. labrosus主要栖息于落叶及半落叶林潮湿的环境中, 偶尔也栖息于常绿林中. L. labrosus分布于厄瓜多尔西海岸的北部、中部、南部; 秘鲁西海岸的北部、中部, 分布地海拔可达600 m; 及位于南厄瓜多尔和北秘鲁海拔高达1 300 m的干燥的安第斯山谷. 其分布地区包括了厄瓜多尔和秘鲁海岸的潮湿的、季节性干燥的森林. 在安第斯山脉斜坡的潮湿地带,L. labrosus与其他3种细趾蟾科的分布区重叠, 但表现为生境分离. 其分布特征与其他几种活动区域受限的两栖动物相似.Tumbesian地区应被认为是地方特有两栖动物的分布区. Choco和Tumbesian的中间区域是L.labrosus与其他细趾蟾科的生境分布重叠区, 其生态及气候特征使其形成了独特的动物区系, 包括几种地方特有物种. 因此该地区应被划为西厄瓜多尔地方种区域.

  20. DIET OF DIRECT-DEVELOPING FROGS (ANURA: CRAUGASTORIDAE: Pristimantis FROM THE ANDES OF WESTERN COLOMBIA

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    Juan Carlos GARCIA-R

    2014-05-01

    Full Text Available We studied the diet of 15 montane frog species of the genus Pristimantis (Craugastoridae from the Andes of Western Colombia to determine the diet range, breadth of niche and overlap among species.  We identified 499 prey items from stomach and intestinal contents of 154 specimens. Prey items were included in 74 different categories. The most common 15 prey categories accounted for 65 % of all frogs’ diet. The invertebrate families Isotomidae, Chironomidae, Formicidae, and Tipulidae were the most abundant categories and accounted for 32 % of the frogs’ diet. Ten of the 15 frog species were found with at least one item of Araneae. Coleoptera and Tipulidae were found in nine frog species, and Acari and Carabidae in eight frog species. In general, beetles were found in gastrointestinal tracts of all species examined, except for P. quantus, but interpretation needs caution because only one individual of this species was caught. Pristimantis hectus showed a specialized diet, consuming mainly dipterans of the family Chironomidae, while the remaining species showed a generalist diet. Pristimantis palmeri showed niche overlap with P. erythropleura (Фjk = 0.69, P. myops (Фjk = 0.64, and P. orpacobates (Фjk = 0.64. Our results suggest that most of the frogs species studied are generalist, foraging opportunistically on dipterans, arachnids, collembolans, coleopterans, and hymenopterans. Here, we report the diet of montane Pristimantis species and discuss the results in comparison with data on related species in montane and lowland regionsDieta de ranas de desarrollo directo (Anura: Craugastoridae: Pristimantis de los Andes occidentales de ColombiaEstudiamos la dieta de 15 especies de ranas montanas del género Pristimantis (Craugastoridae en la Cordillera Occidental de Colombia para determinar su variación, amplitud y traslape de nicho. En los contenidos estomacales e intestinales de 154 especímenes se identificaron 499 presas que fueron

  1. Fine scale gene flow and individual movements among subpopulations of Centrolene prosoblepon (Anura: Centrolenidae

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    Jeanne M Robertson

    2008-03-01

    Full Text Available Dispersal capabilities determine and maintain local gene flow, and this has implications for population persistence and/or recolonization following environmental perturbations (natural or anthropogenic, disease outbreaks, or other demographic collapses. To predict recolonization and understand dispersal capacity in a stream-breeding frog, we examined individual movement patterns and gene flow among four subpopulations of the Neotropical glassfrog, Centrolene prosoblepon, at a mid-elevation cloud forest site at El Copé, Panama. We measured male movement directly during a two year mark-recapture study, and indirectly with gene flow estimates from mitochondrial DNA sequences (mtDNA. Individuals of this species showed strong site fidelity: over two years, male frogs in all four headwater streams moved very little (mean = 2.33 m; mode = 0 m. Nine individuals changed streams within one or two years, moving 675-1 108 m. For those males moving more than 10 m, movement was biased upstream (p ST = 0.007, p = 0.325 but gene flow was more limited across greater distances (CT = 0.322, p = 0.065, even within the same drainage network. Lowland populations of C. prosoblepon potentially act as an important source of colonists for upland populations in this watershed. Rev. Biol. Trop. 56 (1: 13-26. Epub 2008 March 31.La capacidad de dispersión determina y mantiene el flujo genético local, y esto tiene implicaciones para la persistencia poblacional y/o la recolonización que sigue a perturbaciones ambientales. Examinamos patrones individuales de movimiento y flujo genético entre subpoblaciones de Centrolene prosoblepon (Anura: Centrolenidae en un sitio de elevación media en El Copé, Panamá. Medimos directamente el movimiento de los machos durante un estudio de marcado-recaptura, e indirectamente con estimaciones de flujo genético a partir de secuencias de ADN mitocondrial (mtDNA. Los individuos mostraron fuerte fidelidad a su lugar: por más de dos a

  2. Survey of helminths, ectoparasites, and chytrid fungus of an introduced population of cane toads, Rhinella marina (Anura: Bufonidae), from Grenada

    Science.gov (United States)

    Drake, Michael C.; Zieger, Ulrike; Groszkowski, Andrew; Gallardo, Bruce; Sages, Patti; Reavis, Roslyn; Faircloth, Leslie; Jacobson, Krystin; Lonce, Nicholas; Pinckney, Rhonda D.; Cole, Rebecca Ann

    2014-01-01

    One hundred specimens of Rhinella marina, (Anura: Bufonidae) collected in St. George's parish, Grenada, from September 2010 to August 2011, were examined for the presence of ectoparasites and helminths. Ninety-five (95%) were parasitized by 1 or more parasite species. Nine species of parasites were found: 1 digenean, 2 acanthocephalans, 4 nematodes, 1 arthropod and 1 pentastome. The endoparasites represented 98.9% of the total number of parasite specimens collected. Grenada represents a new locality record for Mesocoelium monas, Raillietiella frenatus, Pseudoacanthacephalus sp., Aplectana sp., Physocephalus sp., Acanthacephala cystacanth, and Physalopteridae larvae. The digenean M. monas occurred with the highest prevalence of 82%, contrasting many studies of R. marina where nematodes dominate the parasite infracommunity. Female toads were found to have a significantly higher prevalence of Amblyomma dissimile than male toads. Only 2 parasites exhibited a significant difference between wet and dry season with Parapharyngodon grenadensis prevalence highest in the wet season and A. dissimile prevalence highest during the dry season. Additionally, A. dissimilewas significantly more abundant during the dry season.

  3. Skeletal muscle-melanocyte association during tadpole tail resorption in a tropical frog, Clinotarsus curtipes Jerdon (Anura, Ranoidea).

    Science.gov (United States)

    Divya, Lekha; Beyo, Reston S; Sreejith, Parameswaran; Akbarsha, Mohammad A; Oommen, Oommen V

    2010-05-01

    We tested the hypothesis that melanin has a role as a molecule within the thyroid-mediated cascade. Light microscopic and ultrastructural changes in the skeletal muscle during tail resorption in tadpoles of the tropical frog Clinotarsus curtipes Jerdon (Anura: Ranoidea) were observed. Light microscopic analysis at metamorphic stage XVIII showed a melanized epidermis. A gradual migration of melanocytes from the epidermis to the dermis and filopodia of melanocytes pervading the skeletal muscle preceded tail resorption. The invasion of melanocytes into the muscle bundles coincided with the breakdown of the muscle bundles into sarcolytes and the arrival of macrophages at this site. This would suggest that the melanocyte-sarcolyte association signals the arrival of macrophages at these sites as metamorphosis progressed. Melanophages, macrophages with melanin granules, were observed at the climax stage of XXIII. The sarcolytes and the melanin granules were phagocytosed by macrophages so as to completely cleanse the exocytic muscle debris and the melanin granules. The presence of large melanomacrophage centers in the tadpole liver at metamorphic climax suggests that these phagocytic macrophages were further processed in the liver and, likely, in the spleen. It is proposed that melanin, a byzantine molecule, has a role in the cascade of events leading to tail resorption in anuran tadpoles.

  4. Phylogenetic relationships of Chilean leptodactylids: a molecular approach based on mitochondrial genes 12S and 16S Relaciones filogenéticas de los leptodactílidos chilenos: una aproximación molecular basada en los genes mitocondriales 12S y 16S

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    CLAUDIO CORREA

    2006-12-01

    Full Text Available Most Chilean amphibians belong to the subfamily Telmatobiinae (Anura, Leptodactylidae. Several phylogenetic studies of Leptodactylidae and Telmatobiinae, based principally on morphological characters, have implicitly suggested closer relationships of some species of the Telmatobiinae with members of other subfamilies of leptodactylids, including the leptodactyline genus Pleurodema which is present in Chile. Furthermore, a growing number of molecular studies suggest a non monophyletic status for Telmatobiinae, although none of these studies have investigated the phylogenetic relationships of this subfamily. We compared partial sequences of the ribosomal mitochondrial genes 12S and 16S to determine the phylogenetic relationships of Chilean leptodactylids and its position within the modern anurans (Neobatrachia. We included 22 species from nine of the 10 genera of telmatobiines present in Chile (Alsodes, Atelognathus, Batrachyla, Caudiverbera, Eupsophus, Hylorina, Insuetophrynus, Telmatobufo and Telmatobius, two species of the genus Pleurodema, and one species of Rhinodermatidae, which is considered a leptodactylid derivative family by some authors. We also included 51 species representing most of the families that compose Neobatrachia. Phylogenetic reconstructions were performed using the methods of maximum parsimony, maximum likelihood and Bayesian inference. The topologies obtained in all the analyses indicate that Telmatobiinae is a polyphyletic assemblage, composed by species belonging to Hyloidea (most of the genera and species more related to Australasian taxa (the clade Caudiverbera + Telmatobufo, defined as the tribe Calyptocephalellini. These molecular data support groups based on other kinds of evidence (Caudiverbera + Telmatobufo, Alsodes + Eupsophus and Batrachyla + Hylorina and raise new phylogenetic hypotheses for several genera of telmatobiines (Atelognathus with Batrachyla and Hylorina, Insuetophrynus + Rhinoderma. The phylogenetic

  5. morphology of kaloula rugifera and k.borealis tadpoles (anura:microhylidae:kaloula verrucosa group)in china

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    the external morphology and internal oral features of the tadpoles of kaloula rugifera and k.borealis are described in this paper.similarities between these two larvae include external morphology,oral disc,internal oral features (floor and roof),terminal mouth,lateral eyes,single midventral spiracle,absence of keratinized jaw sheaths and labial teeth,absence of lingual papillae and postnarial arena,while the body of k.rugifera is bigger than that of k.borealis at stages from 36 to 39 and the number of papillae in the buccal cavity is 12-19 and 9-16,respectively in the two species.all the similarities and differences of the two species illustrate that the tadpoles within the family microhylidae could be attributed to assistance in clarifying a certain taxonomic treatment in microhylidae.

  6. Revisión taxonómica de Alytes grandis Brunner (Amphibia, Anura

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    Sanchiz, B.

    1986-12-01

    Full Text Available The holotype and only existing remain referred to Alytes grandis Brunner, 1957, presumably a discoglossid frog from the German Pleistocene, is examined and compared with other living and fossil Palaearctic anurans. The analysis rejects its validity as an independent extinct species, as The material is clearly within the known variability of living Rana temporaria Linnaeus, 1758, of which it should be considered merely a sinonym.

    Se examina el holotipo y único resto atribuido de Alytes grandis Brunner, 1957, un supuesto discoglósido del Pleistoceno alemán, comparándose con otros anuros actuales y fósiles del Paleártico. El análisis permite desechar su pertenencia a una especie extinta independiente, siendo en cambio atribuible con toda claridad a la viviente Rana temporaria Linnaeus, 1758, de la que debe considerarse sinónimo.
    Zum systematischen Status von Alytes grandis Brunner, 1957 (Amphibia, Anura. Der bislang einzig bekannte und von Brunner (1957 beschriebene Rest zu Alytes grandis aus pleistozänen Ablagerungen der Breitenberghöhle bei Gössweinstein (Fränk, Alb wird beschrieben und aufgrund ausführlicher Vergleichsuntersuchungen der rezenten Art Rana temporaria Linnaeus, 1758, zugeordnet, Alytes grandis Brunner, 1957, ist somit als synonyrn zu Rana temporaria zu betrachten.

  7. Sarcophagidae and Calliphoridae related to Rhinella schneideri (Anura, Bufonidae, Bothrops moojeni (Reptilia, Serpentes and Mabuya frenata (Reptilia, Lacertilia carcasses in Brasília, Brazil

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    Roger Maia Dias Ledo

    2012-09-01

    Full Text Available Sarcophagidae and Calliphoridae related to Rhinella schneideri (Anura, Bufonidae, Bothrops moojeni (Reptilia, Serpentes and Mabuya frenata (Reptilia, Lacertilia carcasses in Brasília, Brazil. This paper presents a list of necrophagous insects associated with small size carrions of two reptiles and one amphibian, found in areas of riparian forests and Cerrado sensu stricto physiognomies in a Conservation Unit located in Brasilia, Distrito Federal. We found seven species of insects related to these carcasses, being five Sarcophagidae, one Calliphoridae and one Braconidae parasitoid wasp. Lucilia eximia and Peckia (Pattonella intermutans were the most abundant species in the study, corroborating with other studies that suggests that these species have specializations for colonization of small size animal carcasses.

  8. Archaeobatrachian paraphyly and pangaean diversification of crown-group frogs.

    Science.gov (United States)

    Roelants, Kim; Bossuyt, Franky

    2005-02-01

    Current models for the early diversification of living frogs inferred from morphological, ontogenetic, or DNA sequence data invoke very different scenarios of character evolution and biogeography. To explore central controversies on the phylogeny of Anura, we analyzed nearly 4000 base pairs of mitochondrial and nuclear DNA for the major frog lineages. Likelihood-based analyses of this data set are congruent with morphological evidence in supporting a paraphyletic arrangement of archaeobatrachian frogs, with an (Ascaphus + Leiopelma) clade as the sister-group of all other living anurans. The stability of this outcome is reinforced by screening for phylogenetic bias resulting from site-specific rate variation, homoplasy, or the obligatory use of distantly related outgroups. Twenty-one alternative branching and rooting hypotheses were evaluated using a nonparametric multicomparison test and parametric bootstrapping. Relaxed molecular clock estimates situate the emergence of crown-group anurans in the Triassic, approximately 55 million years prior to their first appearance in the fossil record. The existence of at least four extant frog lineages on the supercontinent Pangaea before its breakup gains support from the estimation that three early splits between Laurasia- and Gondwana-associated families coincide with the initial rifting of these landmasses. This observation outlines the potential significance of this breakup event in the formation of separate Mesozoic faunal assemblages in both hemispheres.

  9. catalogue of the type specimens of amphibians and reptiles in the herpetological museum of chengdu institute of biology,chinese academy of sciences:i.rhacophoridae (anura,amphibia)

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    in order to facilitate herpetological research for all the herpetologists both in and outside of china,we will report all the type specimens of amphibia and reptilia deposited in the herpetological museum of chengdu institute of biology (cib),chinese academy of sciences in series.this report focuses on the family rhacophoridae of anura in amphibia,including 13 species.the contents of the report include synonym lists and generic transfer of type species,measurements of type specimens,particularly for those with no previously published measurement data,and chromosomal data for each species.

  10. Riqueza de espécies, ambientes de reproduçáo e temporada da vocalizaçao da anurofauna em Três Barras do Paraná, Brasil (Amphibia: Anura

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    Bernarde, Paulo Sérgio

    2000-09-01

    Full Text Available Foi realizado um levantamento de espécies de anuros na região do Parque Estadual do Rio Guarani (25º25'S; 53º15'W, Município de Três Barras do Paraná, sudoeste do Estado do Paraná, Brasil. Os ambientes de reprodução e o período de vocalização foram registrados para a maioria das espécies. Foram encontradas 23 espécies pertencentes às seguintes famílias: Bufonidae (1, Centrolenidae (1, Hylidae (9, Leptodactylidae (10, Microhylidae (1 e Ranidae (1. A riqueza de espécies desta localidade foi mais similar com a anurofauna do Município de Londrina (Coeficiente de Semelhança Biogeográfica = 0,8, possivelmente porque ambas regiões apresentam o mesmo tipo de formação vegetal (Floresta Estacional Semidecídua e estão localizadas no terceiro planalto paranaense. A survey of anurans species were realized in the region of State Park Guarani River (25º25'S; 53º15'W, Municipality of Três Barras do Paraná, southwestern of Paraná State, Brazil. The breeding sites and vocalization period were registered from mostly of the species. Anuran fauna of the region is composed by 23 species, distributed in 6 families, namely: Bufonidae (1, Centrolenidae (1, Hylidae (9, Leptodactylidae (10, Microhylidae (1 and Ranidae (1. The species richness of this locality was more similar to the anuran fauna of Londrina Municipality (Coeficient of Biogeographic Resemblance = 0,8, possibly because both regions share the same vegetation composition (seasonal semi-deciduous forests and they are located in the third Paraná plateau.

  11. Sarcophagidae and Calliphoridae related to Rhinella schneideri (Anura, Bufonidae, Bothrops moojeni (Reptilia, Serpentes and Mabuya frenata (Reptilia, Lacertilia carcasses in Brasília, Brazil Sarcophagidae e Calliphoridae associados às carcaças de Rhinella schneideri (Anura, Bufonidae, Bothrops moojeni (Reptilia, Serpentes e Mabuya frenata (Reptilia, Lacertilia em Brasília, Distrito Federal, Brasil

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    Roger Maia Dias Ledo

    2012-09-01

    Full Text Available Sarcophagidae and Calliphoridae related to Rhinella schneideri (Anura, Bufonidae, Bothrops moojeni (Reptilia, Serpentes and Mabuya frenata (Reptilia, Lacertilia carcasses in Brasília, Brazil. This paper presents a list of necrophagous insects associated with small size carrions of two reptiles and one amphibian, found in areas of riparian forests and Cerrado sensu stricto physiognomies in a Conservation Unit located in Brasilia, Distrito Federal. We found seven species of insects related to these carcasses, being five Sarcophagidae, one Calliphoridae and one Braconidae parasitoid wasp. Lucilia eximia and Peckia (Pattonella intermutans were the most abundant species in the study, corroborating with other studies that suggests that these species have specializations for colonization of small size animal carcasses.Sarcophagidae e Calliphoridae associados às carcaças de Rhinella schneideri (Anura, Bufonidae, Bothrops moojeni (Reptilia, Serpentes e Mabuya frenata (Reptilia, Lacertilia em Brasília, Distrito Federal, Brasil. Este trabalho apresenta uma lista de insetos decompositores associados a carcaças de pequeno porte de dois répteis e de um anfíbio, encontrados em áreas de matas de galeria e de cerrado sensu stricto em unidades de conservação do Distrito Federal. Foram encontradas sete espécies de insetos associados a essas carcaças, sendo cinco sarcofagídeos, um califorídeo e uma vespa parasitóide Braconidae. Lucilia eximia e Peckia (Pattonella intermutans foram as espécies mais abundantes, corroborando com outros estudos que sugerem que estas espécies apresentam especializações para a colonização de carcaças menores.

  12. The tadpole of Hypsiboas atlanticus (Anura, Hylidae from northeastern Brazil O girino de Hypsiboas atlanticus (Anura, Hylidae do nordeste do Brasil

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    Filipe A. C. do Nascimento

    2009-12-01

    Full Text Available The tadpole of Hypsiboas atlanticus (Caramaschi & Velosa, 1996 is described from the municipality of Maceió, State of Alagoas, Brazil. At stage 36 the larvae have an overall elliptical body in lateral and dorsal views, oral disc anteroventral, spiracular tube sinistral, and labial tooth row formula 2(1,2/3(1. The oral disc is surrounded, almost completely (anterior medial gap present by a single row of marginal papillae. Described tadpoles of the H. punctatus species group can be differentiated by a combined disc oral features. Additional descriptions of H. punctatus (Schneider, 1799 tadpoles from populations throughout South America may be helpful in determining the status of these populations.O girino de Hypsiboas atlanticus (Caramaschi & Velosa, 1996 é descrito a partir de indivíduos coletados em Maceió, Estado de Alagoas, Brasil. No estágio 36 o corpo é elíptico em vistas lateral e dorsal, o disco oral é anteroventral e o espiráculo é sinistro. A fórmula dental é 2(1,2/3(1. O disco oral é rodeado por uma única fileira de papilas marginais, ausentes anteriormente. Os girinos do grupo de H. punctatus podem ser diferenciados por um conjunto de características do disco oral. Descrições adicionais de girinos de populações de H. punctatus (Schneider, 1799 em toda América do Sul poderá ser útil em determinar seus status.

  13. Los cromosomas meióticos de la rana arborícola Smilisca baudinii (Anura: Hylidae

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    Javier Hernández-Guzmán

    2011-03-01

    Full Text Available La rana arborícola mexicana Smilisca baudinii, es una especie de rana común en Centroamérica. Sin embargo, la biología y genética de la especie, es pobremente conocida a pesar de su importancia para mantener en equilibrio ecológico las selvas tropicales. Con el propósito de contribuir con el conocimiento biológico de esta especie, establecimos el cariotipo típico en meiosis en especímenes recolectados en Tabasco, México, mediante procedimientos citogenéticos estándares. El estudio, se fundamentó en el análisis de 131 dispersiones cromosómicas en estadio meiótico de dos adultos de la especie (una hembra y un macho. El análisis de las metafases, permitió establecer el número modal haploide de 1n=12 cromosomas bivalentes. La fórmula cromosómica del cariotipo haploide, se integró por 12 cromosomas birrámeos caracterizado por 12 pares de cromosomas bivalentes metacéntricos-submetacéntricos (msm. Los conteos en meiosis, hacen suponer como número diploide de cromosomas a un complemento integrado por 2n=24 cromosomas birrámeos. No fue posible observar presencia de cromosomas sexuales, entre las dispersiones meióticas del espécimen hembra y macho. Los resultados sugieren que la estructura cromosómica de S. baudinii, es compartida ampliamente entre las especies de la familia Hylidae y los cromosomas "B" son estructuras importantes en la diversificación de las especies.Meiotic chromosomes of the tree frog Smilisca baudinii (Anura: Hylidae. The Mexican tree frog Smilisca baudinii, is a very common frog in Central America. In spite their importance to keep the ecological equilibrium of the rainforest, its biology and genetics are poorly known. In order to contribute with its biological knowledge, we described the typical meiotic karyotype based in standard cytogenetic protocols to specimens collected in Tabasco, Mexico. The study was centered in the analysis of 131 chromosome spreads at meiotic stage from two adults of the

  14. Pathogenic fungus Batrachochytrium dendrobatidis in marbled water frog Telmatobius marmoratus: first record from Lake Titicaca, Bolivia.

    Science.gov (United States)

    Cossel, John; Lindquist, Erik; Craig, Heather; Luthman, Kyle

    2014-11-13

    The pathogenic fungus Batrachochytrium dendrobatidis (Bd) has been associated with amphibian declines worldwide but has not been well-studied among Critically Endangered amphibian species in Bolivia. We sampled free-living marbled water frogs Telmatobius marmoratus (Anura: Leptodactylidae) from Isla del Sol, Bolivia, for Bd using skin swabs and quantitative polymerase chain reactions. We detected Bd on 44% of T. marmoratus sampled. This is the first record of Bd in amphibians from waters associated with Lake Titicaca, Bolivia. These results further confirm the presence of Bd in Bolivia and substantiate the potential threat of this pathogen to the Critically Endangered, sympatric Titicaca water frog T. culeus and other Andean amphibians.

  15. Bioacústica del canto de advertencia de Ceratophrys cranwelli (Anura: Ceratophrydae Bioacoustic of the advertisement call of Ceratophrys cranwelli (Anura: Ceratophryidae

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    Julián Alonso Valetti

    2013-03-01

    using a DAT record Sony™ TCD-100 with stereo microphone ECM-MS907 Sony™ and tape TDK™ DAT-RGX 60. As males emit their calls floating in temporary ponds, water temperatures were registered after recording the advertisement calls with a digital thermometer TES 1 300±0.1°C. Altogether, 54 calls from 18 males were analyzed. The temporal variables of each advertisement call were measured using oscillograms and sonograms and the analyses of dominant frequency were performed using a spectrogram. Multiple correlation analysis was used to identify the temperature-dependent acoustic variables and the temperature effect on these variables was quantified using linear regression models. The advertisement call of C. cranwelli consists of a single pulse group. Call duration, Pulse duration and Pulse interval decreased with the temperature, whereas the Pulse rate increased with temperature. The temperature-dependent variables were standardized at 25°C according to the linear regression model obtained. The acoustic variables that were correlated with the temperature are the variables which emissions depend on laryngeal muscles and the temperature constraints the contractile properties of muscles. Our results indicated that temperature explains an important fraction of the variability in some acoustic variables (79% in the Pulse rate, and demonstrated the importance of considering the effect of temperature in acoustic components. The results suggest that acoustic variables show geographic variation to compare data with previous works.

  16. Tadpoles of the High-Andean Hyloxalus subpunctatus (Anura: Dendrobatidae with description of larval variation and species distinction by larval morphology

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    Marvin Anganoy-Criollo

    2013-01-01

    Full Text Available This study redescribes the tadpoles of Hyloxalus subpunctatus (Anura: Dendrobatidae based on larvae from the type locality and over most of its geographic range, including all stages of ontogenetic development. I describe tadpoles in the three developmental phases: (1 back-riding tadpoles, (2 free-swimming tadpoles, (3 froglets or individuals in metamorphosis. The larval morphology showed at least two types of variation: ontogenetic variation and variation within each developmental phase. In back-riding tadpoles, the variation in labial tooth rows suggests a pattern of the labial tooth row formation. In free-swimming tadpoles there is variation in the disposition of marginal papillae, i.e., in the number of rows on the margin of the lips, but this variation has no effect on the general aspect of the tadpoles. Moreover, I compared the tadpoles of H. subpunctatus with tadpoles of potential sympatric species and populations previously identified as H. subpunctatus. Interspecific differences and larval characters were found that were useful in delimiting those species.

  17. Uncovering the diversity in the Amazophrynella minuta complex: integrative taxonomy reveals a new species of Amazophrynella (Anura, Bufonidae) from southern Peru.

    Science.gov (United States)

    Rojas, Rommel R; Chaparro, Juan C; Carvalho, Vinícius Tadeu De; Ávila, Robson W; Farias, Izeni Pires; Hrbek, Tomas; Gordo, Marcelo

    2016-01-01

    A new species of the genus Amazophrynella (Anura, Bufonidae) is described from the departments of Madre de Dios, Cusco and Junin in Peru. An integrative taxonomy approach is used. A morphological diagnosis, morphometrics comparisons, description of the advertisement call, and the phylogenetic relationships of the new species are provided. Amazophrynella javierbustamantei sp. n. differs from other species of Amazophrynella by: intermediate body-size (snout-vent length 14.9 mm in males, n = 26 and 19.6 mm in females, n = 20), tuberculate skin texture of body, greatest hand length of the Amazophrynella spp. (3.6 mm in males, n = 26 and 4.6 mm in females, n = 20), venter coloration yellowish, tiny rounded black points covering the venter, and thirteen molecular autapomorphies in the 16S RNA gene. Its distribution varies from 215 to 708 m a.s.l. This discovery highlights the importance of the remnant forest in preserving the biodiversity in Peru, and increase in seven the species formally described in the genus Amazophrynella.

  18. Uncovering the diversity in the Amazophrynella minuta complex: integrative taxonomy reveals a new species of Amazophrynella (Anura, Bufonidae) from southern Peru

    Science.gov (United States)

    Rojas, Rommel R.; Chaparro, Juan C.; Carvalho, Vinícius Tadeu De; Ávila, Robson W.; Farias, Izeni Pires; Hrbek, Tomas; Gordo, Marcelo

    2016-01-01

    Abstract A new species of the genus Amazophrynella (Anura, Bufonidae) is described from the departments of Madre de Dios, Cusco and Junin in Peru. An integrative taxonomy approach is used. A morphological diagnosis, morphometrics comparisons, description of the advertisement call, and the phylogenetic relationships of the new species are provided. Amazophrynella javierbustamantei sp. n. differs from other species of Amazophrynella by: intermediate body-size (snout-vent length 14.9 mm in males, n = 26 and 19.6 mm in females, n = 20), tuberculate skin texture of body, greatest hand length of the Amazophrynella spp. (3.6 mm in males, n = 26 and 4.6 mm in females, n = 20), venter coloration yellowish, tiny rounded black points covering the venter, and thirteen molecular autapomorphies in the 16S RNA gene. Its distribution varies from 215 to 708 m a.s.l. This discovery highlights the importance of the remnant forest in preserving the biodiversity in Peru, and increase in seven the species formally described in the genus Amazophrynella. PMID:27047239

  19. Effects of nonylphenol on early embryonic development, pigmentation and 3,5,3'-triiodothyronine-induced metamorphosis in Bombina orientalis (Amphibia: Anura).

    Science.gov (United States)

    Park, Chan Jin; Kang, Han Seung; Gye, Myung Chan

    2010-11-01

    Nonylphenol (NP) is an estrogenic endocrine disruptor in many aquatic species. In an effort to highlight the developmental toxicity of NP in amphibians, we examined the effects of NP on the embryonic survival, tadpole growth, melanophore development and metamorphosis of a native Korean amphibian species, Bombina orientalis (Anura). When treated to fertilized eggs, 1 μM NP significantly decreased embryonic survival at 48 h post fertilization (p.f.), suggesting that 1 μM NP can exert systemic toxicity in B. orientalis embryos. In the surviving embryos, there were no significant differences in malformation rates between NP-treated embryos and controls at 240 h p.f., suggesting no or low teratogenicity of NP in B. orientalis embryos. Below LC(50) NP significantly decreased body growth and development of melanophores at 0.1 μM, suggesting that NP far below the LC(50) targets multiple developmental events in tadpoles of this frog species. In metamorphosis assay using the premetamorphic tadpoles (corresponding to Nieuwkoop Faber stage 53 in Xenopus laevis) exogenous 3,5,3'-triiodothyronine (T3)-induced tail resorption was significantly decreased by 1 μM NP. However, NP (0.1 and 1 μM)-only treatment did not affected total body T3 and T4 levels, suggesting that NP at tested concentrations inhibits thyroid hormones action but not the synthesis of hormones during metamorphosis.

  20. Morphological and genetic differentiation of Bufo toads: two cryptic species in Western Europe (Anura, Bufonidae)

    NARCIS (Netherlands)

    Arntzen, J.W.; McAtear, J.; Recuero, E.; Ziermann, J.M.; Ohler, A.; Alphen, van J.; Martínez-Solano, I.

    2013-01-01

    The Common toad Bufo bufo sensu lato is a widespread, morphologically conserved taxon. Recent studies have uncovered deep genetic differentiation between population groups, highlighting the need to revise the current taxonomy of the group and recognize additional species. Here we investigate

  1. Morphological evolution from aquatic to terrestrial in the genus Oreolalax (Amphibia, Anura, Megophryidae)

    Institute of Scientific and Technical Information of China (English)

    Gang Wei; Bin Wang; Ning Xu; Zizhong Li; Jianping Jiang

    2009-01-01

    A phylogeny of 17 species in the genus Oreolalax is reconstructed based on 21 morphological characters from adult specimens, skeleton specimens, tadpoles and eggs. Four species groups are recognized, of which the O. rugosus species group is the most primitive, the O. weigoldi species group is the second, the O. omeimontis species group is the third and the O. pingii species group is the most recently diversified. Based on the evolutional tendency of the morphological characters on the phylogenetic tree, it is proposed that the evolution of tympanum, tympanic annulus, columella, spoon-like cartilage and the web between toes reflect the habit changes from aquatic to terrestrial. Thus, Oreolalax is regarded as one important representative genus to study further the evolution of morphological characters from aquatic to terrestrial.

  2. Mitochondrial genes reveal cryptic diversity in plant-breeding frogs from Madagascar (Anura, Mantellidae, Guibemantis).

    Science.gov (United States)

    Lehtinen, Richard M; Nussbaum, Ronald A; Richards, Christina M; Cannatella, David C; Vences, Miguel

    2007-09-01

    One group of mantellid frogs from Madagascar (subgenus Pandanusicola of Guibemantis) includes species that complete larval development in the water-filled leaf axils of rainforest plants. This group consists of six described species: G. albolineatus, G. bicalcaratus, G. flavobrunneus, G. liber, G. pulcher, and G. punctatus. We sequenced the 12S and 16S mitochondrial rRNA genes ( approximately 1.8 kb) from multiple specimens (35 total) of all six species to assess phylogenetic relationships within this group. All reconstructions strongly supported G. liber as part of the Pandanusicola clade, even though this species does not breed in plant leaf axils. This result confirms a striking reversal of reproductive specialization. However, all analyses also indicated that specimens assigned to G. liber include genetically distinct allopatric forms that do not form a monophyletic group. Most other taxa that were adequately sampled (G. bicalcaratus, G. flavobrunneus, and G. pulcher) likewise consist of several genetically distinct lineages that do not form monophyletic groups. These results suggest that many of the recognized species in this group are complexes of cryptic species.

  3. Carbaryl-induced histopathologic alterations on testes of levantine frog, Pelophylax bedriagae (Anura: Ranidae).

    Science.gov (United States)

    Çakıcı, Özlem

    2013-07-01

    The aim of the study was to investigate for the first time histopathologic effects of carbaryl on the testes of adult frog, Pelophylax bedriagae. Frogs were exposed to carbaryl once by oral gavage in concentrations of 0.05, 0.1 and 0.2 mg/g. After 96 h, frogs were euthanized and dissected. Histopathological changes were more prominent in medium- (0.1 mg/g) and high-dose (0.2 mg/g) groups than in the low-dose (0.05 mg/g) group. In the low-dose group, shrinkage of some seminiferous tubules was observed. In the medium-dose group, an enlargement of interstitial spaces and germ cell necrosis were detected. In the high-dose group, prominent tubule deformation was determined. Germ cell necrosis in seminiferous tubules was frequently seen. In addition, congestion, hemorrhage, cellular infiltration and fibrosis were detected. According to these findings, it is clear that carbaryl affects male fertility in P. bedriagae.

  4. The first species of Aplastodiscus endemic to the Brazilian Cerrado (Anura, Hylidae)

    Science.gov (United States)

    Berneck, Bianca V. M.; Giaretta, Ariovaldo A.; Brandão, Reuber A.; Cruz, Carlos A. G.; Haddad, Célio F. B.

    2017-01-01

    Abstract The genus Aplastodiscus includes 14 nominal species in four monophyletic groups with occurrence in the Atlantic Forest and Brazilian Cerrado (Brazilian Savanna) of South America. A recent study reviewed the taxonomy and phylogenetic relationships of the genus and suggested a third species for the Aplastodiscus perviridis Group. Herein, on the basis of morphology and advertisement call, we describe this species and test its monophyly. The new species is the only Aplastodiscus with endemic occurrence in the Cerrado Biome. In addition, its geographical distribution and conservation status are discussed. PMID:28138301

  5. The phylogenetic position and diversity of the enigmatic mongrel frog Nothophryne Poynton, 1963 (Amphibia, Anura).

    Science.gov (United States)

    Bittencourt-Silva, Gabriela B; Conradie, Werner; Siu-Ting, Karen; Tolley, Krystal A; Channing, Alan; Cunningham, Michael; Farooq, Harith M; Menegon, Michele; Loader, Simon P

    2016-06-01

    The phylogenetic relationships of the African mongrel frog genus Nothophryne are poorly understood. We provide the first molecular assessment of the phylogenetic position of, and diversity within, this monotypic genus from across its range-the Afromontane regions of Malawi and Mozambique. Our analysis using a two-tiered phylogenetic approach allowed us to place the genus in Pyxicephalidae. Within the family, Nothophryne grouped with Tomopterna, a hypothesis judged significantly better than alternative hypotheses proposed based on morphology. Our analyses of populations across the range of Nothophryne suggest the presence of several cryptic species, at least one species per mountain. Formal recognition of these species is pending but there is a major conservation concern for these narrowly distributed populations in an area impacted by major habitat change. The phylogenetic tree of pyxicephalids is used to examine evolution of life history, ancestral habitat, and biogeography of this group. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. An elusive new species of Marsupial Frog (Anura: Hemiphractidae: Gastrotheca from the Andes of northern Peru

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    William E. Duellman

    2013-06-01

    Full Text Available A new species of marsupial frog, genus Gastrotheca, is described from high-elevation grasslands in the Andes in Región Amazonas in northernPeru, where even calling males are well hidden in deep moss. The new species is distinguished from all congeners by its unique color pattern that includes a narrow, blackbordered, yellow middorsal stripe. The species apparently belongs to the Gastrotheca plumbea Group, which ranges in the Andes from northern Colombia to northern Peru.

  7. Flutamide effects on morphology of reproductive organs and liver of Neotropical Anura, Rhinella schneideri.

    Science.gov (United States)

    de Gregorio, Lara S; Franco-Belussi, Lilian; Gomes, Fernando R; de Oliveira, Classius

    2016-07-01

    Water contamination is one of the factors influencing the decline of amphibians. Flutamide is an antiandrogenic medicine that occurs as water contaminant. This compound especially affects the reproductive organs, but it can also show hepatotoxic effects. The Bufonidae family has a peculiar organ named Bidder's organ, considered by some authors as a rudimentary ovary, but capable to respond to some external stimuli. This study investigated flutamide effects on testes and Bidder's organ germ cells, liver pigmentation, and sexual hormones levels in Rhinella schneideri males. We randomly divided 15 males in three groups (N=5): two groups were injected with flutamide, at 1 and 5mg/kg, while the control group received only mineral oil, for 7days. After euthanasia, blood samples were collected and the organs were sent to histological routine. In the testes, both treatments caused an increase in spermatogonia and spermatocytes, and a decrease in spermatozoa and locular area. In the Bidder's organ, the final diplotene oocytes increased, but the initial diplotene, degrading and atresic oocytes reduced in both treatments. The lipofuscin in the Bidder's organ was not affected. In the liver, melanin and lipofuscin increased only for the 1mg/kg flutamide treatment. The 5mg/kg treatment did not affect the liver. Serum testosterone and estradiol levels did not vary compared with the control group. This compound has antiandrogenic activity, which can affect the spermatogenetic process. The decrease in degrading and atresic Bidderian oocytes indicated that flutamide could stimulate the organ, retarding the degradation processes. The increase in liver melanin, which has protective role, and lipofuscin, a sign of degradation, indicates that flutamide cause hepatotoxic effects. So we conclude that flutamide negatively affects the testes, especially by reducing the sperm area, and the liver, inducing cell degradation and producing protective responses. Furthermore, the compound

  8. Toxic effects of carbaryl on the histology of testes of Bufotes variabilis (Anura: Bufonidae

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    Ozlem Cakici

    2015-06-01

    Full Text Available This study was designed to investigate histopathologic effects of carbaryl on the testes of adult toad, Bufotes variabilis. To that end, animals were exposed to carbaryl once by oral gavage (low dose: 50 µg/g, medium dose: 100 µg/g and high dose: 200 µg/g. After 96 h, toads were euthanized. In low-dose group, some seminiferous tubules lost their regular shape. Also, the enlargement of interstitial spaces among tubules and germ cell necrosis were determined. A weak hemorrhage was observed among some tubules. In medium-dose group, germ cell necrosis was detected in many seminiferous tubules. This time, a weak hemorrhage was detected within tubules. In the high dose group, an increase in the number of disorganized tubules were observed. Vacuolization and necrosis in germ cells of seminiferous tubules were frequently seen. According to these findings, carbaryl caused dose-related histopathological damage in testis of B. variabilis. Based on these findings, this study clearly shows that carbaryl affects male fertility in B. variabilis.

  9. The tadpole of Scinax melanodactylus (Lourenço, Luna & Pombal Jr, 2014) (Amphibia, Anura, Hylidae).

    Science.gov (United States)

    Abreu, Rafael Oliveira De; Napoli, Marcelo Felgueiras; Trevisan, Camila Costa; Camardelli, Milena; Dória, Thais Andrade Ferreira; Silva, Lucas Menezes

    2015-07-06

    Scinax melanodactylus is a small treefrog distributed within the Tropical Atlantic morphoclimatic domain (see Ab'Sáber 1977 for South American morphoclimatic domains), from northern Espírito Santo state to Sergipe state in Brazil (Lourenço et al. 2014). The species is usually found inhabiting herbaceous and shrubby xerophytic vegetation (e.g. terrestrial tank-bromeliads) from sandy plains of beach ridges known in Brazil as Restingas (see Rocha et al. 2007 for a Restinga definition), and also the edge of forest areas with temporary ponds and/or permanent lakes and streams near these environments (Bastazini et al. 2007, as Scinax agilis; Lourenço et al. 2014). Scinax melanodactylus is currently placed in the S. catharinae species group (Lourenço et al. 2014), which in turn is included in the S. catharinae clade (sensu Faivovich et al. 2005). The S. catharinae clade is currently comprised of 46 species, 33 placed in the catharinae group and 13 in the perpusillus group (Faivovich et al. 2010, Silva & Alves-da-Silva 2011, Lourenço et al. 2014, Frost 2015). From these, 32 species have tadpoles with external morphology and oral disc formerly described. Here, we describe the external morphology, oral disc and color patterns of the previously unknown tadpole of S. melanodactylus.

  10. Description of a new Allobates (Anura, Dendrobatidae from the eastern Andean piedmont, Venezuela

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    César Luis Barrio-Amorós

    2009-12-01

    Full Text Available We describe a new nurse frog in the genus Allobates (Dendrobatidae from Río Negro, Municipio Córdoba, Estado Táchira, in western Venezuela. This species is a leaflitter inhabitant of primary and secondary lowland rainforest at altitudes from 400 to 1000 m. The new species is similar to the species in the Allobates marchesianus group and is restricted to the slopes of the western Venezuelan Andes. It differs from its congeners by having an irregularly spotted dorsalpattern, diffuse oblique lateral stripe, ventrolateral stripe and yellowish belly on males.

  11. Karyological and flow cytometric evidence of triploid specimens in Bufo viridis (Amphibia Anura

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    D Cavallo

    2010-01-01

    Full Text Available Karyological and flow cytometric (FCM analyses were performed on a group of 14 green toads of the Bufo viridis species from seven Eurasian populations. Both approaches gave concordant results concerning the DNA ploidy level. All the populations examined were represented exclusively by diploid or tetraploid specimens, except one, where triploids were found. Results evidenced an interpopulation variability in DNA content against the same ploidy level, as well as an unusually high number of triploids in a particular reproductive place. The origin of polyploidy and the presence and persistence of a high number of triploids in a particular population are discussed.

  12. A new species of Andinobates (Amphibia: Anura: Dendrobatidae) from west central Panama.

    Science.gov (United States)

    Batista, Abel; Jaramillo, César A; Ponce, Marcos; Crawford, Andrew J

    2014-09-24

    Dendrobatid frogs are among the best known anurans in the world, mainly due to their toxicity and associated bright colors. A recently described dendrobatid genus, Andinobates, comprises frogs distributed among the Colombian Andes and Panama. During field work in the Distrito de Donoso, Colón province, Panama, we found a poison frog that we here describe as a new species. The new species belongs to the A. minutus species group and is described herein as Andinobates geminisae sp. nov. This new species differs from all other members of the group by having uniformly orange smooth skin over the entire body and a distinctive male advertisement call. The new species is smaller than other colorful dendrobatids present in the area, such as Oophaga pumilio and O. vicentei. We also provide molecular phylogenetic analyses of mitochondrial DNA sequences of dendrobatids and summarize genetic distances among Andinobates species. Andinobates geminisae occurs in Caribbean versant rainforest on the westernmost edge of the known distribution of A. minutus, and represents the fourth species within this genus in Panama. This is vulnerable to habitat loss and excessive harvesting and requires immediate conservation plans to preserve this species with a restricted geographic range.

  13. The genotoxic effects of the imidacloprid-based insecticide formulation Glacoxan Imida on Montevideo tree frog Hypsiboas pulchellus tadpoles (Anura, Hylidae).

    Science.gov (United States)

    Pérez-Iglesias, J M; Ruiz de Arcaute, C; Nikoloff, N; Dury, L; Soloneski, S; Natale, G S; Larramendy, M L

    2014-06-01

    The neonicotinoid insecticide imidacloprid (IMI) affects the insect central nervous system and is successfully applied to control pests for a variety of agricultural crops. In the current study, acute toxicity and genotoxicity of the IMI-containing commercial formulation insecticide Glacoxan Imida (35 percent IMI) was evaluated on Hypsiboas pulchellus (Anura: Hylidae) tadpoles exposed under laboratory conditions. A lethal effect was evaluated as the end point for lethality, whereas micronucleus (MN) frequency and DNA single-strand breaks evaluated by the single cell gel electrophoresis (SCGE) assay were employed as end points for genotoxicity. Sublethal end points were assayed within the 12.5-37.5mg/L IMI concentration range. Experiments were performed on tadpoles at stage 36 (range, 35-37) according to the classification proposed by Gosner. Lethality studies revealed an LC50 96h value of 52.622mg/L IMI. Increased frequency of MNs was only observed when 25.0mg/L was assayed for 96h, whereas no other nuclear abnormalities were induced. Increase of the genetic damage index was observed at 48h of treatment within the 12.5-37.5mg/L concentration range, whereas an increased frequency of DNA damage was observed only in tadpoles treated with 37.5mg/L IMI for 96h. This study represents the first evidence of the acute lethal and genotoxic effects exerted by IMI on tadpoles of an amphibian species native to Argentina under laboratory conditions. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Larval morphology and advertisement call of Phyllodytes acuminatus Bokermann, 1966 (Anura: Hylidae) from Northeastern Brazil.

    Science.gov (United States)

    Campos, Thamires F; De Lima, Marcelo G; Do Nascimento, Filipe Augusto C; Dos Santos, Ednilza M

    2014-03-13

    This paper describes the tadpole and advertisement call of Phyllodytes acuminatus, based on specimens from the Parque Nacional do Catimbau, in the municipality of Buíque, State of Pernambuco, Northeastern Brazil. The overall morphology of P. acuminatus tadpole is similar to that of most species of the genus. The presence of a double row of marginal papillae surrounding all the oral apparatus (except on most of the upper labium which has a dorsal gap) was a characteristic that differentiate P. acuminatus from the other species of the genus. Furthermore, the call structure of the species (unpulsed notes with harmonic structure) fits it in the group composed of P. kautskyi and P. melanomystax.

  15. Energy substrate utilization during nightly vocal activity in three species of Scinax (Anura/Hylidae).

    Science.gov (United States)

    Carvalho, José Eduardo; Gomes, Fernando Ribeiro; Navas, Carlos Arturo

    2008-05-01

    Anuran amphibians exhibit different patterns of energy substrate utilization that correlate with the intensity of vocal and locomotor activities. Given the remarkable differences among species in breeding and feeding strategies, and the different ways energy is used in the whole animal, the suggested correlations between calling and locomotor behavior and the level of energy substrates in the muscles responsible for such activities are more complex than previously reported. We explored the relationships between calling and locomotor behavior and energy supply to trunk and hindlimb muscles, respectively, within the ecologically diverse tree-frog genus Scinax. Specifically, we measured the relative amount of carbohydrates and lipids in these two groups of muscles, and in the liver of three species of Scinax that differ in vocal and locomotor performance, and compared our results with those of two other species for which comparable data are available. We also compared the contents of lipids and carbohydrates of conspecific males collected at the beginning and after 4 h of calling activity. The stomach content to potential feeding opportunities across species was also assessed in both groups of males. Scinax hiemalis and S. rizibilis exhibit comparatively low and episodic calling during long periods of activity whereas S. crospedospilus calls at higher rates over shorter periods. Male S. hiemalis had highest levels of trunk muscle glycogen followed by those of S. rizilbilis and S. crospedospilus, respectively. There was no correlation between total lipid content in trunk muscle and calling rate among different species, suggesting that other metabolic aspects may be responsible for the energetic support for vocal activity. The levels of lipids and carbohydrates in trunk and hindlimb muscles and liver of males collected at the beginning and 4 h into the calling period were similar across species, so the extent of energetic reserves does not appear to constrain vocal or

  16. Nest structure, incubation and and hatching in the trinidadian leaf-frog Phyllomedusa trinitatis (Anura: Hylidae

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    J. Roger Downie

    2013-06-01

    Full Text Available New findings on nesting and hatching are reported for the leaf-nesting tree frog Phyllomedusa trinitatis. Nest height and leaf cover(one or many leaves, well or poorly covered were very variable. Contrary to a previous report, egless jelly capsules we scattered amongst the eggs, with substancial jelly plugs located above and below the egg clutch. Plugs were composed of capsules embedded in a matrix of somewhat different composition. The upper plug acted as a barrier to water entry. Contrary to previous reports, isolated eggs could develop in aquatic media, the later stage on entry the better: Aeration and salt composition of the water influences this ability. Egg clutches developes equally well whether the covering leaves were alive or dead. Single eggs incubated in water hatched prematurely; when placed in water, eggs near hatching stage hatched within a short time; such eggs on a dry or damp substrate did not hatch till much later. The hatching of any embryo in a group appeared to act as a stimulus to neighbours to hatch. Observations ons nests with the covering leaves replaced by clingfilm showed that emergence is preceded by a lenghty period of hatching behavior, with individuals hatchins, wriggling and stimulating larger and larger groups to hatch, and releasing a frothy fluid wich leads to the dissolution of the lower jelly plug and emergence of the hatchlings. Contrary to a previous report, hatching gland cells were observable on the laterodorsal surface of the head. When hatchings emerged from the nest, they were mostly at Gosner stage 25 with gills fully resorbed. When earlier embryos were induced to hatch, they rapidly shortened their external gills. These findings are discussed in comparison with observations on the related genus Agalychnis.

  17. Caracterización de Hyla guentheri Boulenger 1886 (Amphibia, Anura, Hylidae

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    Langone, José A.

    1997-01-01

    Full Text Available Del análisis del holotipo de H. guentheri se concluye que esta es una especie válida y diferente de Hyla pulchella. Se verifica la identidad del holotipo y se descartan otros ejemplares asignados a la serie tipo de esta especie. Del estudio se deduce que H. guentheri es conocida de unas pocas localidades de los estados brasileños de Rio Grande do Sul y Santa Catarina. Sus relaciones filogenéticas no son claras y dependen de una definición formal de los grupos polytaenia y pulchella. Analysis of the holotype of H. guentheri indicates that it is a valid species and different from Hyla pulchella. The identity of the holotype is verified and other specimens incorrectly assigned to the type series of this species are rejected as syntypes. At present H. guentheri is known from the Brazilian States of Rio Grande do Sul and Santa Catharina. The phylogenetic relationships of this species are not clear and depend on a formal definition of the polytaenia and pulchella groups.

  18. Chromosome analysis of five Brazilian species of poison frogs (Anura: Dendrobatidae)

    Indian Academy of Sciences (India)

    Paula Camargo Rodrigues; Odair Aguiar; Flávia Serpieri; Albertina Pimentel Lima; Masao Uetanebaro; Shirlei Maria Recco-Pimentel

    2011-04-01

    Dendrobatid frogs have undergone an extensive systematic reorganization based on recent molecular findings. The present work describes karyotypes of the Brazilian species Adelphobates castaneoticus, A. quinquevittatus, Ameerega picta, A. galactonotus and Dendrobates tinctorius which were compared to each other and with previously described related species. All karyotypes consisted of $2n = 18$ chromosomes, except for A. picta which had $2n = 24$. The karyotypes of the Adelphobates and D. tinctorius species were highly similar to each other and to the other $2n = 18$ previously studied species, revealing conserved karyotypic characteristics in both genera. In recent phylogenetic studies, all Adelphobates species were grouped in a clade separated from the Dendrobates species. Thus, we hypothesized that their common karyotypic traits may have a distinct origin by chromosome rearrangements and mutations. In A. picta, with $2n = 24$, chromosome features of pairs from 1 to 8 are shared with other previously karyotyped species within this genus. Hence, the A. picta data reinforced that the C-banding pattern and the NOR location are species-specific traits in the genus Ameerega. Moreover, the Ameerega monophyletism proposed by previous phylogenetic studies indicates that the karyotypic differences among species in this genus result from a long divergence time.

  19. Una nueva especie del grupo Hyloscirtus larinopygion (Amphibia: Anura: Hylidae del suroccidente de Colombia

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    Jonh Jairo Mueses-Cisneros

    2008-01-01

    Full Text Available Se describe una nueva especie del grupo Hyloscirtus larinopygion del Nudo de los Pastos en el departamento de Nariño, Colombia. Hyloscirtus tigrinus sp. nov. puede ser distinguida fácilmente de sus especies similares por la presencia de un tubérculo calcar carnoso y prominente, además de su distintivo patrón de coloración. Se realizan algunos comentarios sobre la coloración de la garganta y coloración ventral en Hyloscirtus caucanus, H. larinopygion, H. lindae y H. tigrinus. La coloración de la garganta es altamente variable, por lo tanto no puede ser utilizada para diagnosticar a estas especies.A new species of the Hyloscirtus larinopygion group from Nudo de los Pastos, Nariño department, Colombia is described. Hyloscirtus tigrinus sp. nov. can be distinguished easily from similar species by the presence of a fleshy and prominent calcar tubercle and by its distinctive color pattern. Some remarks on throat and ventral coloration in Hyloscirtus caucanus, H. larinopygion, H. lindae and H. tigrinus are presented. The throat coloration is highly variable and cannot be used to diagnose any of these species.

  20. Three new species of Proceratophrys Miranda-Ribeiro 1920 from Brazilian Cerrado (Anura, Odontophrynidae).

    Science.gov (United States)

    Brandão, Reuber Albuquerque; Caramaschi, Ulisses; Vaz-Silva, Wilian; Campos, Leandro Ambrósio

    2013-12-20

    Based on the analyses of specimens collected at several areas in the Cerrado domain from Central Brazil and others housed in scientific collections and on specimens collected at the type-locality, herein we describe three new species belonging to the P. cristiceps group: Proceratophrys bagnoi sp. nov., from UHE Serra da Mesa power plant (13°49'47.5"S, 48°19'17"W; 570 m a.s.l.; WGS84 datum), Municipality of Minaçu, State of Goiás; Proceratophrys branti sp. nov., from Jalapão, Municipality of Mateiros (05o15'25"S, 48o12'00"W; 109 m a.s.l.; WGS84 datum), State of Tocantins; and Proceratophrys dibernardoi sp. nov., Municipality of Mineiros (17o33'52"S, 52o33'20"W; 803 m a.s.l.; WGS84 datum), State of Goiás. The diversity of Proceratophrys in Brazilian Cerrado is still underscored and several species will be described in the following years.

  1. Systematics of the Osteocephalus buckleyi species complex (Anura, Hylidae from Ecuador and Peru

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    Santiago Ron

    2012-10-01

    Full Text Available We present a new phylogeny, based on DNA sequences of mitochondrial and nuclear genes, for frogs of the genus Osteocephalus with emphasis in the Osteocephalus buckleyi species complex. Genetic, morphologic, and advertisement call data are combined to define species boundaries and describe new species. The phylogeny shows strong support for: (1 a basal position of O. taurinus + O. oophagus, (2 a clade containing phytotelmata breeding species, and (3 a clade that corresponds to the O. buckleyi species complex. Our results document a large proportion of hidden diversity within a set of populations that were previously treated as a single, widely distributed species, O. buckleyi. Individuals assignable to O. buckleyi formed a paraphyletic group relative to O. verruciger and O. cabrerai and contained four species, one of which is O. buckleyi sensu stricto and three are new. Two of the new species are shared between Ecuador and Peru (O. vilmae sp. n. and O. cannatellai sp. n. and one is distributed in the Amazon region of southern Peru (O. germani sp. n.. We discuss the difficulties of using morphological characters to define species boundaries and propose a hypothesis to explain them.

  2. The breeding behaviour, advertisement call and tadpole of Limnonectes dabanus (Anura: Dicroglossidae).

    Science.gov (United States)

    Rowley, Jodi J L; Le, Duong Thi Thuy; Hoang, Huy Duc; Altig, Ronald

    2014-11-04

    Fanged frogs (Limnonectes) are a group of dicroglossid frogs from Asia that often have reversed sexual dimorphism with larger males. Limnonectes dabanus is a poorly known species of fanged frog from forested habitats in southern Vietnam and eastern Cambodia. Adult males exhibit an extreme degree of megacephaly and possess bizarre head ornamentation. L. dabanus breeds in shallow, non-flowing or very slow-flowing pools, puddles, and drainage ditches. Eggs are laid as a widely spaced array, and the larvae have a morphology typical of pond-dwelling tadpoles. Although males of the species lack vocal sacs, they produce a low-pitched (0.4-0.6 kHz), single-note advertisement call that sounds like a drop of water falling into water. Given the spacing of calling males, presence of multiple females near breeding sites, and reversed sexual dimorphism, the mating system of L. dabanus may be an example of resource-defense polygyny, and the massive head of the male is likely used in male combat.

  3. The First Bromeligenous Species of Dendropsophus (Anura: Hylidae) from Brazil's Atlantic Forest

    Science.gov (United States)

    Ferreira, Rodrigo B.; Faivovich, Julián; Beard, Karen H.; Pombal, José P.

    2015-01-01

    We describe a new treefrog species of Dendropsophus collected on rocky outcrops in the Brazilian Atlantic Forest. Ecologically, the new species can be distinguished from all known congeners by having a larval phase associated with rainwater accumulated in bromeliad phytotelms instead of temporary or lentic water bodies. Phylogenetic analysis based on molecular data confirms that the new species is a member of Dendropsophus; our analysis does not assign it to any recognized species group in the genus. Morphologically, based on comparison with the 96 known congeners, the new species is diagnosed by its small size, framed dorsal color pattern, and short webbing between toes IV-V. The advertisement call is composed of a moderate-pitched two-note call (~5 kHz). The territorial call contains more notes and pulses than the advertisement call. Field observations suggest that this new bromeligenous species uses a variety of bromeliad species to breed in, and may be both territorial and exhibit male parental care. PMID:26650515

  4. Isolation and sequencing of the HMG domain of ten Sox genes from Odorrana schmackeri (Amphibia: Anura

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    Ning Wang

    2009-03-01

    Full Text Available Sox (SRY-related HMG-box genes encode a family of transcriptional regulators, which are characterized by a conserved 79-amino acid domain known as HMG-box. They play essential roles in a diverse range of processes including sex determination and the development of the central nervous system (CNS, neural crest and endoderm. In this paper, the HMG domain of ten distinct Sox gene family members (os-Sox2, os-Sox3a, os-Sox3b, os-Sox4, os-Sox11a, os-Sox11b, os-Sox14a, os-Sox14b, os-Sox21a, os-Sox21b were isolated from both male and female Odorrana schmackeri (Boettger, 1892 using PCR, and no sexual differences were found. Molecular phylogenetic analysis of the HMG domain suggested that these ten Sox genes are members of the SoxB and SoxC groups. In addition, sequence analysis suggested that four Sox genes (os-Sox3, os-Sox11, os-Sox14, os-Sox21 were duplicated. The duplication-degeneration-complementation model should be implied to explain the evolution and diversity of the Sox gene family in O. schmackeri.

  5. Leaping frogs (Anura: Ranixalidae of the Western Ghats of India: An integrated taxonomic review

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    Neelesh Dahanukar

    2016-09-01

    Full Text Available Leaping frogs of the family Ranixalidae are endemic to the Western Ghats of India and are currently placed in a single genus, Indirana.  Based on specimens collected from their entire range and a comprehensive study of type material defining all known species, we propose a revised taxonomy for the leaping frogs using an integrative approach including an analysis of the mitochondrial 16S rRNA and nuclear rhodopsin genes, as well as multivariate morphometrics. Both genetic and morphological analyses suggest that the genus Indirana is paraphyletic and a distinct monophyletic group, Walkerana gen. nov is described herein.  The new genus is separated from Indirana sensu stricto by an apomorphic character state of reduced webbing, with one phalange free on the first and second toe (vs. no free phalanges, two phalanges free on the third and fifth toe (vs. one free phalange, and three phalanges free on the fourth toe (vs. 2–2½ phalanges free.  This review includes (i identification of lectotypes and redescription of three species of the genus Walkerana; (ii identification of lectotypes for Indirana beddomii and I. semipalmata and their redescription; (iii redescription of I. brachytarsus and I. gundia; and (iv descriptions of four new species, namely, I. duboisi and I. tysoni from north of the Palghat gap, and I. yadera and I. sarojamma from south of the Palghat gap; and (iv a key to the genera and species in the family Ranixalidae. 

  6. Molecular and Morphological Study of Leaping Frogs (Anura, Ranixalidae) with Description of Two New Species

    Science.gov (United States)

    Garg, Sonali; Biju, S. D.

    2016-01-01

    The monotypic anuran family Ranixalidae is endemic to India, with a predominant distribution in the Western Ghats, a region that is home to several unique amphibian lineages. It is also one of the three ancient anuran families that diversified on the Indian landmass long before several larger radiations of extant frogs in this region. In recent years, ranixalids have been subjected to DNA barcoding and systematic studies. Nearly half of the presently recognized species in this family have been described over the last three years, along with recognition of a new genus to accommodate three previously known members. Our surveys in the Western Ghats further suggest the presence of undescribed diversity in this group, thereby increasing former diversity estimates. Based on rapid genetic identification using a mitochondrial gene, followed by phylogenetic analyses with an additional nuclear gene and detailed morphological studies including examination of museum specimens, new collections, and available literature, here we describe two new species belonging to the genus Indirana from the Western Ghats states of Karnataka and Kerala. We also provide new genetic and morphological data along with confirmed distribution records for all the species known prior to this study. This updated systematic revision of family Ranixalidae will facilitate future studies and provide vital information for conservation assessment of these relic frogs. PMID:27851823

  7. Two new species of fanged frogs from Peninsular Malaysia (Anura: Dicroglossidae).

    Science.gov (United States)

    Matsui, Masafumi; Belabut, Daicus M; Ahmad, Norhayati

    2014-11-03

    Taxonomic status of fanged frogs from the Peninsular Malaysia, previously assigned to Limnonectes kuhlii, is assessed using genetic and morphological approaches. Phylogenetic relationships inferred from sequences of the mitochondrial and nuclear genes revealed that the fanged frogs from the Peninsula form a monophyletic group and are clearly divergent from other species previously, or even now, assigned to L. kuhlii from Mainland Southeast Asia. In both mtDNA and nuDNA phylogeny, the Malay Peninsula clade diverges into two lineages, one from north (Larut Hill, Perak, and Hulu Terengganu, Terengganu) and another from south (Genting Highlands, Pahang, and Gombak, Selangor). These lineages are separated by large genetic distances, comparable with those observed between some other species of L. kuhlii-like frogs. Although the two lineages are very similar morphologically, they are distinguishable in several morphological traits and are considered heterospecific. We therefore describe them as L. utara sp. nov. and L. selatan sp. nov. These new species differ from all other species of kuhlii-like frogs from Mainland Southeast Asia by the surface of tibia, which is densely covered by large warts. 

  8. Light shines through the spindrift--phylogeny of African torrent frogs (Amphibia, Anura, Petropedetidae).

    Science.gov (United States)

    Barej, Michael F; Rödel, Mark-Oliver; Loader, Simon P; Menegon, Michele; Gonwouo, Nono L; Penner, Johannes; Gvoždík, Václav; Günther, Rainer; Bell, Rayna C; Nagel, Peter; Schmitz, Andreas

    2014-02-01

    Torrent frogs of the genus Petropedetes Reichenow, 1874 as currently understood have a disjunct distribution with species endemic to West, Central or East Africa. We herein present a phylogenetic analysis including all but one of the currently described 12 species of the genus. Maximum Likelihood and Bayesian analyses of combined nuclear (rag1, SIA, BDNF) and mitochondrial (16S, 12S, cytb) genes of more than 3500 base pairs, revealed clades corresponding to the three sub-Saharan regions. Molecular results are confirmed by morphological differences. Surprisingly, the three geographic clades do not form a monophyletic group with respect to closely related families Pyxicephalidae and Conrauidae and therefore require taxonomic changes. We resurrect Arthroleptides Nieden, 1911 for the East African taxa. The Central African taxa remain in the genus Petropedetes. The West African members are placed in the new genus Odontobatrachus gen. nov. The taxonomic position of the new genus remains incertae sedis as it was not assigned to any of the four families included in our analyses. Potential new species have been detected within all three major clades, pointing to a still not fully clarified diversity within African torrent frogs.

  9. A New Species of Frog (Anura: Dicroglossidae) Discovered from the Mega City of Dhaka.

    Science.gov (United States)

    Howlader, Mohammad Sajid Ali; Nair, Abhilash; Merilä, Juha

    2016-01-01

    We describe a new species of frog of the genus Zakerana discovered from the urban core of Dhaka, Bangladesh, one of the most densely populated cities in the world. Although the new species is morphologically similar to the geographically proximate congeners in the Bangladeshi cricket frog group, we show that it can be distinguished from all congeners on the basis of morphological characters, advertisement calls and variation in two mitochondrial DNA genes (12S rRNA and 16S rRNA). Apart from several diagnostic differences in body proportions, the new species differs from other Zakerana species in having a flattened snout (from ventral view) projecting over the lower jaw, and diagnostic trapezoid-shaped red markings on the vocal sac in males. Molecular genetic analyses show that the new species is highly divergent (3.1-20.1% sequence divergence) from all congeneric species, and forms a well-supported clade with its sister species, Zakerana asmati. The discovery of a new amphibian species from the urban core of Dhaka together with several recent descriptions of new amphibian species from Bangladesh may indicate that more amphibian species remain to be discovered from this country.

  10. A new species of Andean poison frog, Andinobates (Anura: Dendrobatidae), from the northwestern Andes of Colombia.

    Science.gov (United States)

    Amézquita, Adolfo; Márquez, Roberto; Medina, Ricardo; Mejía-Vargas, Daniel; Kahn, Ted R; Suárez, Gustavo; Mazariegos, Luis

    2013-01-01

    The poison frogs of the Colombian Andes, Pacific lowlands and Panama have been recently recognized as a new, monophyletic and well-supported genus: Andinobates. The species richness and distribution within Andinobates remain poorly understood due to the paucity of geographic, genetic and phenotypic data. Here we use a combination of molecular, bioacoustic and morphometric evidence to describe a new species of Andean poison frog: Andinobates cassidyhornae sp. nov. from the high elevation cloud forests of the Colombian Cordillera Occidental, in the northwestern Andes. The new species is associated to the bombetes group and characterized by a unique combination of ventral and dorsal color patterns. Data on 1119 bp from two mitochondrial markers allowed us to reject the null hypotheses that A. cassidyhornae sp. nov. is part of the phenotypically similar and geographically less distant species: A. opisthomelas, A. virolinensis or A. bombetes. The best available phylogenetic trees and the genetic distance to other Andinobates species further support this decision. Altogether, the advertisement call parameters unambiguously separated A. cassidyhornae sp. nov. calls from the calls of the three closest species. The new species adds to a poorly known and highly endangered genus of poison frogs that requires further studies and urgent conservation measures.

  11. Systematics of the Osteocephalus buckleyi species complex (Anura, Hylidae) from Ecuador and Peru

    Science.gov (United States)

    Ron, Santiago R.; Venegas, Pablo J.; Toral, Eduardo; Morley Read; Diego A. Ortiz; Manzano, Andrea L.

    2012-01-01

    Abstract We present a new phylogeny, based on DNA sequences of mitochondrial and nuclear genes, for frogs of the genus Osteocephalus with emphasis in the Osteocephalus buckleyi species complex. Genetic, morphologic, and advertisement call data are combined to define species boundaries and describe new species. The phylogeny shows strong support for: (1) a basal position of Osteocephalus taurinus + Osteocephalus oophagus, (2) a clade containing phytotelmata breeding species, and (3) a clade that corresponds to the Osteocephalus buckleyi species complex. Our results document a large proportion of hidden diversity within a set of populations that were previously treated as a single, widely distributed species, Osteocephalus buckleyi. Individuals assignable to Osteocephalus buckleyi formed a paraphyletic group relative to Osteocephalus verruciger and Osteocephalus cabrerai and contained four species, one of which is Osteocephalus buckleyi sensu stricto and three are new. Two of the new species are shared between Ecuador and Peru (Osteocephalus vilmae sp. n. and Osteocephalus cannatellai sp. n.) and one is distributed in the Amazon region of southern Peru (Osteocephalus germani sp. n.) We discuss the difficulties of using morphological characters to define species boundaries and propose a hypothesis to explain them. PMID:23166473

  12. The advertisement call, color patterns and distribution of Ischnocnema izecksohni (Caramaschi and Kisteumacher, 1989 (Anura, Brachycephalidae

    Directory of Open Access Journals (Sweden)

    Pedro P. G. Taucce

    2012-01-01

    Full Text Available Ischnocnema izecksohni inhabits the gallery forests from the Quadrilátero Ferrífero, Southern Espinhaço range, state of Minas Gerais, southeastern Brazil, and it is considered endemic to this region. Its closest related species is I. nasuta according to the original description. We describe the advertisement call of I. izecksohni based on specimens recorded and collected at the municipality of Nova Lima, state of Minas Gerais, distant about 10 km straight line from its type locality. The advertisement call consists of a group of notes emitted sporadically without a regular interval between the calls. Call duration (n = 36 calls in four individuals ranged from 1.03 to 1.85 s (= 1.52 ± 0.21 s and the call rise time from 0.66 to 1.52 s (= 1.16 ± 0.25 s, with 34-57 notes per call (= 47.42 ± 6.03. Peak frequency ranged from 2250 to 2625 Hz, the dominant frequency from 1317.8 to 3128.0 Hz and interval between notes from 22.00 to 41.00 ms (= 28.63 ± 0.03 ms. From the examination of herpetological collections, morphological and bioacoustical data we extended the species known distribution ca. 200 km eastward, to ten new localities, all of them outside the Quadrilátero Ferrífero region, at the Mantiqueira mountain range. We analyzed color patterns and we find some dorsal patterns not described at the original description of I. izecksohni. We also make some comments concerning the taxonomic status of I. izecksohni and I. nasuta.

  13. Molecular evidence for cryptic candidate species in Iberian Pelodytes (Anura, Pelodytidae).

    Science.gov (United States)

    Díaz-Rodríguez, Jesús; Gonçalves, Helena; Sequeira, Fernando; Sousa-Neves, Tiago; Tejedo, Miguel; Ferrand, Nuno; Martínez-Solano, Iñigo

    2015-02-01

    Species delineation is a central topic in evolutionary biology, with current efforts focused on developing efficient analytical tools to extract the most information from molecular data and provide objective and repeatable results. In this paper we use a multilocus dataset (mtDNA and two nuclear markers) in a geographically comprehensive population sample across Iberia and Western Europe to delineate candidate species in a morphologically cryptic species group, Parsley frogs (genus Pelodytes). Pelodytes is the sole extant representative of an ancient, historically widely distributed anuran clade that currently includes three species: P. caucasicus in the Caucasus; P. punctatus in Western Europe, from Portugal to North-Western Italy; and P. ibericus in Southern Iberia. Phylogenetic analyses recovered four major well-supported haplotype clades in Western Europe, corresponding to well demarcated geographical subdivisions and exhibiting contrasting demographic histories. Splitting times date back to the Plio-Pleistocene and are very close in time. Species-tree analyses recovered one of these species lineages, corresponding to P. ibericus (lineage B), as the sister taxon to the other three major species lineages, distributed respectively in: western Iberian Peninsula, along the Atlantic coast and part of central Portugal (lineage A); Central and Eastern Spain (lineage C); and North-eastern Spain, France and North-western Italy (lineage D). The latter is in turn subdivided into two sub-clades, one in SE France and NW Italy and the other one from NE Spain to NW France, suggesting the existence of a Mediterranean-Atlantic corridor along the Garonne river. An information theory-based validation approach implemented in SpedeSTEM supports an arrangement of four candidate species, suggesting the need for a taxonomic revision of Western European Pelodytes.

  14. New material of Beelzebufo, a hyperossified frog (Amphibia: Anura from the late cretaceous of Madagascar.

    Directory of Open Access Journals (Sweden)

    Susan E Evans

    Full Text Available The extant anuran fauna of Madagascar is exceptionally rich and almost completely endemic. In recent years, many new species have been described and understanding of the history and relationships of this fauna has been greatly advanced by molecular studies, but very little is known of the fossil history of frogs on the island. Beelzebufo ampinga, the first named pre-Holocene frog from Madagascar, was described in 2008 on the basis of numerous disarticulated cranial and postcranial elements from the Upper Cretaceous (Maastrichtian Maevarano Formation of Madagascar. These specimens documented the presence of a hyperossified taxon that differed strikingly from extant Malagasy frogs in its large size and heavy coarse cranial exostosis. Here we describe and analyse new, articulated, and more complete material of the skull, vertebral column, and hind limb, as well as additional isolated elements discovered since 2008. μCT scans allow a detailed understanding of both internal and external morphology and permit a more accurate reconstruction. The new material shows Beelzebufo to have been even more bizarre than originally interpreted, with large posterolateral skull flanges and sculptured vertebral spine tables. The apparent absence of a tympanic membrane, the strong cranial exostosis, and vertebral morphology suggest it may have burrowed during seasonally arid conditions, which have been interpreted for the Maevarano Formation from independent sedimentological and taphonomic evidence. New phylogenetic analyses, incorporating both morphological and molecular data, continue to place Beelzebufo with hyloid rather than ranoid frogs. Within Hyloidea, Beelzebufo still groups with the South American Ceratophryidae thus continuing to pose difficulties with both biogeographic interpretations and prior molecular divergence dates.

  15. Predação oportunista de Artibeus planirostris (Spix, 1823 e Carollia perspicillata (Linnaeus, 1758 (Chiroptera, Phyllostomidae por marsupiais e anuro na APA do Rio Curiaú, Amapá, Brasil Opportunistic predation of Artibeus planirostris (Spix, 1823 and Carollia perspicillata (Linnaeus, 1758 (Chiroptera, Phyllostomidae by marsupials and anuran in the APA do Rio Curiaú, Amapá State, Brazil

    Directory of Open Access Journals (Sweden)

    Isai Jorge de Castro

    2011-03-01

    Full Text Available Durante estudos com morcegos em floresta de várzea na APA do Rio Curiaú, Amapá, Brasil, observamos três casos de predações oportunistas de morcegos frugívoros capturados em redes de neblina. Duas destas predações ocorreram por marsupiais e uma por anuro. Artibeus planirostris (Spix, 1823 (Chiroptera, Phyllostomidae foi predado por Didelphis marsupialis Linnaeus, 1758 e Philander opossum (Linnaeus, 1758 (Didelphimorphia, Didelphidae. Carollia perspicillata (Linnaeus, 1758 (Chiroptera, Phyllostomidae foi predado por Leptodactylus pentadactylus (Laurenti, 1768 (Anura, Leptodactylidae. A vocalização dos morcegos provavelmente atraiu os marsupiais para a rede, onde estes os predaram aproveitando que estavam presos. Este tipo de interação pode ocorrer naturalmente, no entanto, com maior dificuldade de registro.We observed three occasional predations of bats captured in mist nets by marsupials and a frog during studies in a várzea forest in the Amapá state. Artibeus planirostris (Spix, 1823 (Chiroptera, Phyllostomidae was preyed upon by Didelphis marsupialis Linnaeus, 1758 and Philander opossum (Linnaeus, 1758 (Didelphimorphia, Didelphidae. Carollia perspicillata (Linnaeus, 1758 (Chiroptera, Phyllostomidae was preyed on by Leptodactylus pentadactylus (Laurenti, 1768 (Anura, Leptodactylidae. The bats vocalizations probably attracted the marsupials and a frog to the mist nets where they preyed. This interaction form can occur naturally, however, are more difficult to observed.

  16. Diversidad, distribución espacio-temporal y turnos de vocalización de anuros (Amphibia, Anura en un área ecotonal del nordeste de Argentina

    Directory of Open Access Journals (Sweden)

    Víctor H. Zaracho

    2015-06-01

    Full Text Available RESUMEN Estudios acerca de la diversidad e historia natural de comunidades de anuros son elementales para distinguir entre fluctuaciones naturales de aquellas causadas por impactos antrópicos (herramienta clave en programas de conservación, evaluar el papel que juegan en la dinámica de los ecosistemas y permitir comparaciones de gradientes de diversidad. En este contexto, se analiza la diversidad, la distribución temporal y espacial, y los turnos de vocalización de anuros de tres sitios de reproducción en los Esteros del Iberá, en el nordeste de Argentina. Los muestreos fueron mensuales entre julio de 2008 y junio de 2010. Se registraron 26 especies pertenecientes a cinco familias: Bufonidae (2, Hylidae (11, Leptodactylidae (11, Microhylidae (1, y Odontophrynidae (1. Se encontraron variaciones en la riqueza de especies por sitio, en el periodo, frecuencia y turno de vocalización y en la abundancia de machos vocalizadores. La riqueza es similar al de otros humedales similares, incluyendo un importante dominio de leptodactílidos e hílidos, patrón frecuente en ensambles neotropicales. La concentración de las especies en actividad de vocalización en los meses más cálidos y lluviosos estuvo asociada con los cambios en la temperatura y en las precipitaciones, las cuales fueron señaladas como algunos de los factores que inician la actividad reproductiva en ambientes estacionales.

  17. Group X

    Energy Technology Data Exchange (ETDEWEB)

    Fields, Susannah

    2007-08-16

    This project is currently under contract for research through the Department of Homeland Security until 2011. The group I was responsible for studying has to remain confidential so as not to affect the current project. All dates, reference links and authors, and other distinguishing characteristics of the original group have been removed from this report. All references to the name of this group or the individual splinter groups has been changed to 'Group X'. I have been collecting texts from a variety of sources intended for the use of recruiting and radicalizing members for Group X splinter groups for the purpose of researching the motivation and intent of leaders of those groups and their influence over the likelihood of group radicalization. This work included visiting many Group X websites to find information on splinter group leaders and finding their statements to new and old members. This proved difficult because the splinter groups of Group X are united in beliefs, but differ in public opinion. They are eager to tear each other down, prove their superiority, and yet remain anonymous. After a few weeks of intense searching, a list of eight recruiting texts and eight radicalizing texts from a variety of Group X leaders were compiled.

  18. [Feeding of two amphibian species (Anura: Hylidae) during the low temperatures season and its relationship with energy storage in Santa Fe, Argentina].

    Science.gov (United States)

    Antoniazzi, Carolina Elizabet; López, Javier Alejandro; Duré, Marta; Falico, Diego Alejandro

    2013-06-01

    Feeding of two amphibian species (Anura: Hylidae) during the low temperatures season and its relationship with energy storage in Santa Fe, Argentina. In environments with thermal and pluvial seasonality such as those of the Middle Paraná River floodplain (Province of Santa Fe, Argentina), most amphibian species reproduce during the warm season and drastically diminish their activity during winter. Even though, a few species remain active during the cold season, such as Hypsiboas pulchellus that has its reproductive peak during the autumn-winter period (and the consequent energy demand). The objective of this study was to analyze and compare the feeding and development of fat bodies during the low temperature season for H. pulchellus and Dendropsophus nanus. We analyzed entire gastrointestinal tract contents of both species (H. pulchellus = 110 specimens; D. nanus = 114 specimens) and applied an index (IRI%) that combines prey abundance, volume and frequency to describe frogs diets; we used fat bodies weights as indicators of stored energy reserves. We compared diet between species with a niche overlap index (Ojk: 0-1) and used null models to ascribe statistical significance to evaluate overlap; and we analyzed variation in empty guts proportions through months and between species. Also, using ANCOVAs we explored differences in fat bodies, number and volume of prey consumed along months, between species and sexes. The most important preys in H. pulchellus diet during the cold season were Araneae (IRI% = 34.96), Chironomidae (IRI% = 33.08), Tipulidae (IRI% = 11.44) and Gryllidae (IR1% = 7.31); while for D. nanus, Chironomidae (IR1% = 48.14), Tipulidae (IRI% = 18.41), Psychodidae (IRI% = 7.44) and Araneae (IRI% = 7.34). Diet overlap between species was elevated (Ojk=0.78) and higher than expected by chance (mean simulated indices: Ojk = 0.04; p[observed > or = expected]<0.01; p[observed < or = expected] = 1). In H. pulchellus there was a monthly variation in number

  19. Group morphology

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.

    2000-01-01

    In its original form, mathematical morphology is a theory of binary image transformations which are invariant under the group of Euclidean translations. This paper surveys and extends constructions of morphological operators which are invariant under a more general group TT, such as the motion group

  20. Group devaluation and group identification

    NARCIS (Netherlands)

    Leach, C.W.; Rodriguez Mosquera, P.M.; Vliek, M.L.W.; Hirt, E.

    2010-01-01

    In three studies, we showed that increased in-group identification after (perceived or actual) group devaluation is an assertion of a (preexisting) positive social identity that counters the negative social identity implied in societal devaluation. Two studies with real-world groups used order manip

  1. Three new species of Pristimantis (Lissamphibia, Anura from montane forests of the Cordillera Yanachaga in Central Peru

    Directory of Open Access Journals (Sweden)

    William E. Duellman

    2007-12-01

    Full Text Available We describe three additional new species of Pristimantis from the Cordillera Yanachaga, a part of the Andes in central Peru. Analyses of DNA sequences of the mitochondrial rRNA genes show that onespecies is a close relative of P. bipunctatus (P. conspicillatus Group, another is a close relative of P. stictogaster (P. peruvianus Group, and the third is related to several species in the P. unistrigatus Group. The first two species are morphologically similar to their closest relatives but occur at lower elevations. Twenty-nine species of Pristimantis and Phrynopus are known from the vicinity of the Cordillera Yanachaga. The number of species, especially of Pristimantis, is high in the humid montane forestin comparison with other sites in humid montane forests in Peru, but the number is lower than on the western slopes of the Andes in Ecuador.

  2. Algebraic Groups

    DEFF Research Database (Denmark)

    2007-01-01

    The workshop continued a series of Oberwolfach meetings on algebraic groups, started in 1971 by Tonny Springer and Jacques Tits who both attended the present conference. This time, the organizers were Michel Brion, Jens Carsten Jantzen, and Raphaël Rouquier. During the last years, the subject...... of algebraic groups (in a broad sense) has seen important developments in several directions, also related to representation theory and algebraic geometry. The workshop aimed at presenting some of these developments in order to make them accessible to a "general audience" of algebraic group......-theorists, and to stimulate contacts between participants. Each of the first four days was dedicated to one area of research that has recently seen decisive progress: \\begin{itemize} \\item structure and classification of wonderful varieties, \\item finite reductive groups and character sheaves, \\item quantum cohomology...

  3. Group Grammar

    Science.gov (United States)

    Adams, Karen

    2015-01-01

    In this article Karen Adams demonstrates how to incorporate group grammar techniques into a classroom activity. In the activity, students practice using the target grammar to do something they naturally enjoy: learning about each other.

  4. The advertisement call of Bokermannohyla flavopicta Leite, Pezzuti & Garcia, 2012 (Anura: Hylidae) from the mountains of Chapada Diamantina, Bahia, Brazil.

    Science.gov (United States)

    Rocha, Pedro Carvalho; Thompson, Julia Resende; Leite, Felipe Sá Fortes; Garcia, Paulo Christiano De Anchietta

    2016-01-07

    Bokermannohyla Faivovich, Haddad, Garcia, Frost, Campbell & Wheeler (2005) is a Brazilian treefrog genus currently composed of 32 species (Brandão et al. 2012; Leite et al. 2012; Frost 2015). The genus comprehends four, putatively monophyletic, species groups: B. circumdata, B. claresignata, B. martinsi, and B. pseudopseudis (sensu Faivovich et al. 2005). The B. pseudopseudis group includes nine species: B. alvarengai (Bokermann 1956), B. flavopicta Leite et al. 2012, B. ibitiguara (Cardoso 1983), B. itapoty Lugli & Haddad 2006a, B. oxente Lugli & Haddad 2006b, B. pseudopseudis (Miranda-Ribeiro 1937), B. sagarana Leite et al. 2011, B. sapiranga Brandão et al. 2012, and B. saxicola (Bokermann 1964).

  5. MUYANG GROUP

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ With its headquarters in the historic city of Yangzhou,Jiangsu Muyang Group Co.,Ltd has since its founding in 1967 grown into a well-known group corporation whose activities cover research&development.project design,manufacturing,installation and services in a multitude of industries including feed machinery and engineering,storage engineering,grain machinery and engineering,environmental protection,conveying equipment and automatic control systems.

  6. Abelian groups

    CERN Document Server

    Fuchs, László

    2015-01-01

    Written by one of the subject’s foremost experts, this book focuses on the central developments and modern methods of the advanced theory of abelian groups, while remaining accessible, as an introduction and reference, to the non-specialist. It provides a coherent source for results scattered throughout the research literature with lots of new proofs. The presentation highlights major trends that have radically changed the modern character of the subject, in particular, the use of homological methods in the structure theory of various classes of abelian groups, and the use of advanced set-theoretical methods in the study of undecidability problems. The treatment of the latter trend includes Shelah’s seminal work on the undecidability in ZFC of Whitehead’s Problem; while the treatment of the former trend includes an extensive (but non-exhaustive) study of p-groups, torsion-free groups, mixed groups, and important classes of groups arising from ring theory. To prepare the reader to tackle these topics, th...

  7. The status and relationships of some East African Earless Toads (Anura, Bufonidae) with a description of a new species

    NARCIS (Netherlands)

    Grandison, A.G.C.

    1972-01-01

    INTRODUCTION In comparing some small Ethiopian Bufo with the descriptions, types and other examples of numerous forms from East and Central African countries I became very much aware of the confusion that exists in the taxonomy and of the need for a revision of this group of dwarf toads. Most of the

  8. Reproductive ecology and behavior of Eleutherodactylus aureolineatus (Anura, Brachycephalidae in the canopy of the Upper Amazon Basin, Ecuador

    Directory of Open Access Journals (Sweden)

    Shawn F. McCracken

    2006-12-01

    Full Text Available Exploration and investigation of the anuran fauna in the canopies of the Upper Amazon Basin has led to the recent discoveries of new species of the genus Eleutherodactylus utilizing the microhabitat within bromeliads. Detailed information on the ecology and natural history of these communities are scarce due, in part, to the difficulty of accessing their habitat. New sampling methods for rainforest canopies have allowed for the collection and observation of the herpetofauna utilizing this habitat. Sexual size dimorphism in Eleutherodactylus aureolineatus, confirms placement in the E. unistrigatus species group and E. lacrimosus assemblage. The described microhabitat, vocalization characteristics, reproductive behavior and egg deposition of E. aureolineatus provides significant ecological background on this poorly documented group of frogs and their important “wetlands in the sky”. The data and observationsherein contribute to the overall understanding of the characters and ecological factors which define the E. lacrimosus assemblage.

  9. Advertisement call of Scinax littoralis and S. angrensis (Amphibia: Anura: Hylidae, with notes on the reproductive activity of S. littoralis

    Directory of Open Access Journals (Sweden)

    Michel V. Garey

    2012-12-01

    Full Text Available Scinax littoralis and S. angrensis are poorly known Atlantic forest endemic species from the Scinax catharinae group, which is known from southern and southeastern Brazil. Herein, we describe the advertisement calls of these two species and compare them to other species within the S. catharinae group. Additionally, we provide information on breeding sites, and calling activity in S. littoralis. Advertisement calls of S. angrensis and S. littoralis are composed of multi-pulsed notes with multiple frequency bands and frequency modulation. Scinax littoralis has a higher minimum and maximum frequency, and lower dominant frequency than S. angrensis, while Scinax littoralis has a longer call. Scinax littoralis appears to be a habitat generalist, occurring from secondary to mature forests, and breeding both in temporary and in permanent ponds. Male S. littoralis were usually observed calling perched on shrub stems, and displayed satellite behavior when the male density was high.

  10. Group Anonymity

    CERN Document Server

    Chertov, Oleg; 10.1007/978-3-642-14058-7_61

    2010-01-01

    In recent years the amount of digital data in the world has risen immensely. But, the more information exists, the greater is the possibility of its unwanted disclosure. Thus, the data privacy protection has become a pressing problem of the present time. The task of individual privacy-preserving is being thoroughly studied nowadays. At the same time, the problem of statistical disclosure control for collective (or group) data is still open. In this paper we propose an effective and relatively simple (wavelet-based) way to provide group anonymity in collective data. We also provide a real-life example to illustrate the method.

  11. Highly complex mitochondrial DNA genealogy in an endemic Japanese subterranean breeding brown frog Rana tagoi (Amphibia, Anura, Ranidae).

    Science.gov (United States)

    Eto, Koshiro; Matsui, Masafumi; Sugahara, Takahiro; Tanaka-Ueno, Tomoko

    2012-10-01

    The endemic Japanese frog Rana tagoi is unique among Holarctic brown frogs in that it breeds in small subterranean streams. Using mitochondrial 16S ribosomal RNA and NADH dehydrogenase subunit 1 genes, we investigated genealogical relationships among geographic samples of this species together with its relative R. sakuraii, which is also a unique stream breeder. These two species together form a monophyletic group, within which both are reciprocally paraphyletic. Rana tagoi is divided into two major clades (Clade A and B) that are composed of 14 genetic groups. Rana sakuraii is included in Clade A and split into two genetic groups, one of which forms a clade (Subclade A-2) with sympatric R. tagoi. This species-level paraphyly appears to be caused by incomplete taxonomy, in addition to introgressive hybridization and/or incomplete lineage sorting. Rana tagoi strongly differs from other Japanese anurans in its geographic pattern of genetic differentiation, most probably in relation to its unique reproductive habits. Taxonomically, R. tagoi surely includes many cryptic species.

  12. Systematics and biogeography of the Hylarana frog (Anura: Ranidae) radiation across tropical Australasia, Southeast Asia, and Africa.

    Science.gov (United States)

    Oliver, Lauren A; Prendini, Elizabeth; Kraus, Fred; Raxworthy, Christopher J

    2015-09-01

    We present an inclusive molecular phylogeny for Hylarana across its global distribution, utilizing two mitochondrial and four nuclear gene regions for 69 of the 97 currently described species. We use phylogenetic methods to test monophyly of Hylarana, determine relationships among ten putative subgenera, identify major clades, reconstruct biogeographic history, and estimate continental dispersal dates. Results support Hylarana as a monophyletic group originating approximately 26.9MYA and comprising eight clades that partly correspond to currently described subgenera plus two new groups. The African and Australasian species each form clades embedded within a paraphyletic Southeast Asian group. We estimate that Africa and Australasia were colonized by Hylarana s.l. from SE Asia approximately 18.7 and 10.8MYA, respectively. Biogeographic reconstructions also support three separate colonization events in India from Southeast Asia. Examination of museum specimens identified morphological characters useful for delineating subgenera and species. We herein elevate all supported subgenera to genus rank and formally describe two new genera to produce a revised taxonomy congruent with our new phylogenetic and biogeographic findings.

  13. Comparación ontogénica de la frecuencia de muda en Rhinella marina (Anura, Bufonidae Ontogenetic comparison of the molting frequency in Rhinella marina (Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    Teófila M. Triana

    2013-03-01

    Full Text Available La muda es un proceso de renovación de la capa externa de la epidermis (estrato corneo de los anfibios, la cual suministra protección contra daños, patógenos y pérdida de agua. Este trabajo evalúa la frecuencia de muda entre juveniles y adultos de Rhinella marina (Linnaeus, 1758 y la tasa de ocurrencia entre el día y la noche. Para esto, se realizaron dos observaciones diarias (7 am y 7 pm, entre Octubre de 2011 y Marzo de 2012, a tres grupos de individuos clasificados según su tamaño longitud rostro-cloaca, como adultos (promedio=80 mm, juveniles medianos (promedio=19 mm y juveniles pequeños (promedio=13 mm. Estos animales fueron colocados en terrarios en el laboratorio y marcados en el dorso a través de un punto hecho con un corrector de tinta. La muda se determinó por la pérdida total de la marca y una coloración brillante en el dorso. Se encontró una diferencia significativa (Kruskal-Wallis, H=19.84, pMolting is a process of constant renewal of the outer layer of epidermis (stratum corneum in amphibians, which provides a barrier against injury, pathogens and evaporative water loss. This paper evaluates the molting frequency between juveniles and adults of Rhinella marina (Linnaeus, 1758 and between the night and day time. Two daily observations, at 7 am and 7 pm, were made between October 2011 and March 2012 to three groups of individuals, classified by their size, snout vent length, as adults (mean=80 mm, medium juveniles (mean=19 mm and small juveniles (mean=13 mm. The animals were placed in terrariums in the laboratory and marked on their back with a spot of correction fluid. The molting was determined by the total loss of the mark and a bright color on the dorsal skin. We found a significant difference (Kruskal-Wallis, H=19.84, p<0.0001 in the molting frequency among the three groups: adults=7.5 days, medium juveniles=5.4 days, and small juveniles=5.3 days. Also, between the number of molting frogs during the night and day

  14. Informal groups

    NARCIS (Netherlands)

    E. van den Berg; P. van Houwelingen; J. de Hart

    2011-01-01

    Original title: Informele groepen Going out running with a group of friends, rather than joining an official sports club. Individuals who decide to take action themselves rather than giving money to good causes. Maintaining contact with others not as a member of an association, but through an Inter

  15. A new "Bat-Voiced" species of Dendropsophus Fitzinger, 1843 (Anura, Hylidae) from the Amazon Basin, Brazil.

    Science.gov (United States)

    Orrico, Victor G D; Peloso, Pedro L V; Sturaro, Marcelo J; Da Silva-Filho, Heriberto F; Neckel-Oliveira, Selvino; Gordo, Marcelo; Faivovich, Julián; Haddad, Célio F B

    2014-11-06

    We describe Dendropsophus ozzyi sp. nov., a new species of treefrog, tentatively included in the Dendropsophus microcephalus Group and most notably diagnosed by the presence of pointed fingers and an advertisement call with a very high dominant frequency. The new species is known from three localities in the Brazilian Amazon forest, two on western State of Pará and one (the type locality) in eastern State of Amazonas (03°56'50"S and 58°26'36"W, 45 m a.s.l.).

  16. A new small frog species of the genus Pristimantis (Anura: Craugastoridae) from the northern paramos of Colombia.

    Science.gov (United States)

    González-Durán, Gustavo A

    2016-01-18

    I describe a new species of a small-sized frog of the genus Pristimantis found in the paramo ecosystem (3700 masl) on the northern slope of Los Nevados National Park, Cordillera Central, department of Caldas, Colombia. This new species is assigned to the Pristimantis leptolophus species-group, given that Toe V is much longer than Toe III and extends to the distal edge of the distal subarticular tubercle on Toe IV. The new species differs from other taxa by its dorsal golden or yellowish color patterns, the absence of nuptial pads, lateral fringes on its fingers and toes, and the absence of vomerine odontophores. Discriminant analyses of morphometric characters of females of P. leptolophus, P. uranobates, and the new species separate the new species by snout-vent length, tibia length, eye diameter, eye-to-nostril distance, tympanum diameter, and length of toe III. Vomer terms frequently used to describe species are reviewed, such as the oblique keels of the vomer and the different forms of the dentigerous process. Species belonging to the high Andean Pristimantis leptolophus species-group are allopatric, suggesting vicariant speciation in different areas of the paramos.

  17. Carbaryl-induced histopathologic alterations in the digestive tract of the Levantine frog, Pelophylax bedriagae (Anura: Ranidae).

    Science.gov (United States)

    Çakici, Özlem

    2014-08-01

    In this study, histopathologic changes following carbaryl exposure for 96 hr were investigated in the digestive tract of Levantine frog, Pelophylax bedriagae. Adult frogs were exposed to carbaryl once by oral gavage in concentrations of 0.05, 0.1, and 0.2 mg/g. Histopathological changes were more prominent in medium- (0.1 mg/g) and high-dose (0.2 mg/g) groups than in the low-dose (0.05 mg/g) group. Esophageal cells showed vacuolization, cellular swelling, nuclear pyknosis, karyolysis, and necrosis. Additionally, esophageal glandular atrophy and infiltration of inflammatory cells around esophageal glands were observed at medium and high doses. In the stomach, there were prominent histopathologic defects such as cellular swelling and necrosis in gastric glands, necrotic cells within the interstitial spaces, separation of epithelial cell layer, congested vessels, and hemorrhage at medium and high doses. In the intestine, detachment of epithelial layer, epithelial cell disorganization, inflammation, and necrosis were detected at medium and high doses. The results of this study showed that carbaryl caused adverse effects on the digestive tract of the Levantine frog, P. bedriagae.

  18. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    The CMS Communications Group, established at the start of 2010, has been busy in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure There are now 55 CMS Centres worldwide that are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin, is the centre of the CMS offline and computing operations, hosting dedicated analysis efforts such as during the CMS Heavy Ion lead-lead running. With a majority of CMS sub-detectors now operating in a “shifterless” mode, many monitoring operations are now routinely performed from there, rather than in the main Control Room at P5. The CMS Communications Group, CERN IT and the EVO team are providing excellent videoconferencing support for the rapidly-increasing number of CMS meetings. In parallel, CERN IT and ...

  19. Lego Group

    DEFF Research Database (Denmark)

    Møller Larsen, Marcus; Pedersen, Torben; Slepniov, Dmitrij

    2010-01-01

    The last years’ rather adventurous journey from 2004 to 2009 had taught the fifth-largest toy-maker in the world - the LEGO Group - the importance of managing the global supply chain effectively. In order to survive the largest internal financial crisis in its roughly 70 years of existence......, the management had, among many initiatives, decided to offshore and outsource a major chunk of its production to Flextronics. In this pursuit of rapid cost-cutting sourcing advantages, the LEGO Group planned to license out as much as 80 per cent of its production besides closing down major parts...... of the production in high cost countries. Confident with the prospects of the new partnership, the company signed a long-term contract with Flextronics. This decision eventually proved itself to have been too hasty, however. Merely three years after the contracts were signed, LEGO management announced that it would...

  20. Group play

    DEFF Research Database (Denmark)

    Tychsen, Anders; Hitchens, Michael; Brolund, Thea

    2008-01-01

    of group dynamics, the influence of the fictional game characters and the comparative play experience between the two formats. The results indicate that group dynamics and the relationship between the players and their digital characters, are integral to the quality of the gaming experience in multiplayer......Role-playing games (RPGs) are a well-known game form, existing in a number of formats, including tabletop, live action, and various digital forms. Despite their popularity, empirical studies of these games are relatively rare. In particular there have been few examinations of the effects...... of the various formats used by RPGs on the gaming experience. This article presents the results of an empirical study, examining how multi-player tabletop RPGs are affected as they are ported to the digital medium. Issues examined include the use of disposition assessments to predict play experience, the effect...

  1. Ecología trófica en larvas de Rhinella arenarum (Anura: Bufonidae en agroecosistemas y sus posibles implicaciones para la conservación Trophic ecology in tadpoles of Rhinella arenarum (Anura: Bufonidae in agroecosystems and their possible implications for conservation

    Directory of Open Access Journals (Sweden)

    Clarisa Bionda

    2012-06-01

    Full Text Available El crecimiento de la agricultura produce perdida del habitat natural, con consecuencias para la biodiversidad de los anfibios. Se analizo la dieta y condición corporal de larvas de anuros de Rhinella arenarum que habitan agroecosistemas. Los muestreos fueron realizados en dos agroecosistemas y en un tercer sitio, no afectado por cultivos. Las larvas capturadas fueron anestesiadas, fijadas y preservadas en formaldehido, se realizaron medidas corporales y se analizo la dieta de las larvas. Se registro diversidad en la oferta alimenticia proporcionada por los distintos ambientes. La dieta tuvo una predominancia de algas Bacillarophyceae, seguidas por Cyanophyceae. Particularmente, los géneros Navicula, Nitzschia, Hantzschia y Gomphonema (clase Bacillarophyceae, fueron importantes en los agroecosistemas. Los géneros Osillatoria, Euglena y Strombomonas (clases Cyanophyceae y Euglenophyceae, predominaron en la dieta de las larvas de anuros en el sitio menos alterado. Las larvas de los sitios más alterados consumen menor cantidad de alimento y registran una menor condición corporal. La presencia de determinadas algas, indicarían un mayor grado de contaminación en los agroecosistemas. La eutrofización de lagunas podría alterar la disponibilidad de alimento para larvas de anuros que podría tener consecuencias poblacionales negativas. Se sugiere el análisis de dietas larvarias como un potencial bioindicador de salubridad ambiental.Trophic ecology in tadpoles of Rhinella arenarum (Anura: Bufonidae in agroecosystems and their possible implications for conservation. The progress of the agriculture border has led an important loss of natural habitats, with significant consequences for biodiversity. In this sense, the studies in anuran amphibian tadpoles inhabiting these environments are relevant, because the larval stage is a phase of population regulation. The aim of this study was to analyze the body condition and diet in Rhinella arenarum

  2. Molecular systematics of terraranas (Anura: Brachycephaloidea) with an assessment of the effects of alignment and optimality criteria.

    Science.gov (United States)

    Padial, José M; Grant, Taran; Frost, Darrel R

    2014-06-26

    Brachycephaloidea is a monophyletic group of frogs with more than 1000 species distributed throughout the New World tropics, subtropics, and Andean regions. Recently, the group has been the target of multiple molecular phylogenetic analyses, resulting in extensive changes in its taxonomy. Here, we test previous hypotheses of phylogenetic relationships for the group by combining available molecular evidence (sequences of 22 genes representing 431 ingroup and 25 outgroup terminals) and performing a tree-alignment analysis under the parsimony optimality criterion using the program POY. To elucidate the effects of alignment and optimality criterion on phylogenetic inferences, we also used the program MAFFT to obtain a similarity-alignment for analysis under both parsimony and maximum likelihood using the programs TNT and GARLI, respectively. Although all three analytical approaches agreed on numerous points, there was also extensive disagreement. Tree-alignment under parsimony supported the monophyly of the ingroup and the sister group relationship of the monophyletic marsupial frogs (Hemiphractidae), while maximum likelihood and parsimony analyses of the MAFFT similarity-alignment did not. All three methods differed with respect to the position of Ceuthomantis smaragdinus (Ceuthomantidae), with tree-alignment using parsimony recovering this species as the sister of Pristimantis + Yunganastes. All analyses rejected the monophyly of Strabomantidae and Strabomantinae as originally defined, and the tree-alignment analysis under parsimony further rejected the recently redefined Craugastoridae and Pristimantinae. Despite the greater emphasis in the systematics literature placed on the choice of optimality criterion for evaluating trees than on the choice of method for aligning DNA sequences, we found that the topological differences attributable to the alignment method were as great as those caused by the optimality criterion. Further, the optimal tree-alignment indicates

  3. Una nueva especie de Atelopus (Amphibia: Anura: Bufonidae del Páramo de Tama, Estado Apure, Venezuela Una nueva especie de Atelopus (Amphibia: Anura: Bufonidae del Páramo de Tama, Estado Apure, Venezuela

    Directory of Open Access Journals (Sweden)

    La Marca Enrique

    1989-09-01

    Full Text Available Se describe una especie nueva de rana, Atelopus tamaense, del páramo el Tama, en el Estado Apure, Venezuela. El taxon se distingue de todos los demás miembros del género por la combinación de extensivo ''webbing" y coloración distintiva. Se suministran datos sobre su morfología externa, piel, coloración, variación intraespecífica, dimorfismo sexual y ecología. Se incluye una clave para la identificación de las especies venezolanas de Atelopus y se hacen algunas comparaciones para diferenciar la especie nueva de las especies de Atelopus colombianas y venezolanas del grupo de A. ignescens al cual pertenece A. tamaense. A new species of frog, Atelopus tamaense, is described from Páramo El Tamá, Estado Apure, Venezuela. The taxon is distinguished from all other members of the genus by the combination of extensive webbing and distinctive coloration. Data are provided for external morphology, skin, coloration, intraspecific variation, sexual dimorphism, and ecology. A key is included to identify Venezuelan Atelopus and some comparisons are given to distinguish the new species from Colombian and Venezuelan species of Atelopus of the A. ignescens group, to which A. tamaense belongs.

  4. Neogene amphibians and reptiles (Caudata, Anura, Gekkota, Lacertilia, and Testudines) from the south of Western Siberia, Russia, and Northeastern Kazakhstan

    Science.gov (United States)

    Zazhigin, Vladimir S.

    2017-01-01

    Background The present-day amphibian and reptile fauna of Western Siberia are the least diverse of the Palaearctic Realm, as a consequence of the unfavourable climatic conditions that predominate in this region. The origin and emergence of these herpetofaunal groups are poorly understood. Aside from the better-explored European Neogene localities yielding amphibian and reptile fossil remains, the Neogene herpetofauna of Western Asia is understudied. The few available data need critical reviews and new interpretations, taking into account the more recent records of the European herpetofauna. The comparison of this previous data with that of European fossil records would provide data on palaeobiogeographic affiliations of the region as well as on the origin and emergence of the present-day fauna of Western Siberia. An overview of the earliest occurrences of certain amphibian lineages is still needed. In addition, studies that address such knowledge gaps can be useful for molecular biologists in their calibration of molecular clocks. Methods and Results In this study, we considered critically reviewed available data from amphibian and reptile fauna from over 40 Western Siberian, Russian and Northeastern Kazakhstan localities, ranging from the Middle Miocene to Early Pleistocene. Herein, we provided new interpretations that arose from our assessment of the previously published and new data. More than 50 amphibians and reptile taxa were identified belonging to families Hynobiidae, Cryptobranchidae, Salamandridae, Palaeobatrachidae, Bombinatoridae, Pelobatidae, Hylidae, Bufonidae, Ranidae, Gekkonidae, Lacertidae, and Emydidae. Palaeobiogeographic analyses were performed for these groups and palaeoprecipitation values were estimated for 12 localities, using the bioclimatic analysis of herpetofaunal assemblages. Conclusion The Neogene assemblage of Western Siberia was found to be dominated by groups of European affinities, such as Palaeobatrachidae, Bombina, Hyla, Bufo

  5. Group Connections: Whole Group Teaching.

    Science.gov (United States)

    Griffiths, Dorothy

    2002-01-01

    A learner-centered approach to adult group instruction involved learners in investigating 20th-century events. The approach allowed learners to concentrate on different activities according to their abilities and gave them opportunities to develop basic skills and practice teamwork. (SK)

  6. A new species of small tree frog, genus Dendropsophus (Anura: Hylidae) from the eastern Amazon lowlands of Ecuador.

    Science.gov (United States)

    Ortega-Andrade, H Mauricio; Ron, Santiago R

    2013-01-01

    We describe a new species of the hylid frog genus Dendropsophus from Amazonian Ecuador. The new species, Dendropsophus shiwiarum sp. nov., appears to be part of the D. microcephalus species group. Dendropsophus shiwiarum differs from its congeners by a combination of: (1) tympanic membrane non-differentiated and annulus evident only ventrally, (2) disc of Finger III and Toe IV with pointed tip, (3) dorsal surfaces of digital discs with a conical tubercle as result of projection of distal phalanx, and (4) small size (SVL < 19 mm). The new species is morphologically most similar to Dendropsophus riveroi. Examination of the type material of the latter suggests that some Ecuadorian populations reported as D. riveroi were misidentified and in fact belong to D. shiwiarum sp. nov.

  7. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    The CMS Communications Group has been busy in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure The 55 CMS Centres worldwide are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin, is the centre of the CMS Offline and Computing operations, and a number of subdetector shifts can now take place there, rather than in the main Control Room at P5. A new CMS meeting room has been equipped for videoconferencing in building 42, next to building 40. Our building 28 meeting room and the facilities at P5 will be refurbished soon and plans are underway to steadily upgrade the ageing equipment in all 15 CMS meeting rooms at CERN. The CMS evaluation of the Vidyo tool indicates that it is not yet ready to be considered as a potential replacement for EVO. The Communications Group provides the CMS-TV (web) cha...

  8. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2010-01-01

    The CMS Communications Group, established at the start of 2010, has been strengthening the activities in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure The Communications Group has invested a lot of effort to support the operations needs of CMS. Hence, the CMS Centres where physicists work on remote CMS shifts, Data Quality Monitoring, and Data Analysis are running very smoothly. There are now 55 CMS Centres worldwide, up from just 16 at the start of CMS data-taking. The latest to join are Imperial College London, the University of Iowa, and the Università di Napoli. The CMS Centre@CERN in Meyrin, which is now full repaired after the major flooding at the beginning of the year, has been at the centre of CMS offline and computing operations, most recently hosting a large fraction of the CMS Heavy Ion community during the lead-lead run. A number of sub-detector shifts can now take pla...

  9. The occurrence of amphibians in bromeliads from a southeastern Brazilian restinga habitat, with special reference to Aparasphenodon brunoi (Anura, Hylidae).

    Science.gov (United States)

    Teixeira, R L; Schineider, J A P; Almeida, G I

    2002-05-01

    Five species of anuran amphibians, all belonging to the family Hylidae, were collected at Praia das Neves, municipality of President Kennedy, southeastern Brazil. The species were represented by four genera: Scinax, Hyla, Aparasphenodon, and Trachycephalus. Four species (A. brunoi, Hyla albomarginata, Scinax altera, and S. cuspidatus) were found during the dry season (August 1999), and two (A. brunoi and Trachycephalus nigromaculatus) in the rainy season (February 2000). Aparasphenodon brunoi was the most abundant species in Praia das Neves. Some reproductive aspects and feeding habits of this hylid were investigated. Aparasphenodon brunoi was found mainly inside the bromeliad Aechmea lingulata, the largest plant analyzed. Fifteen specimens were collected during the dry season (August 1999) (11 males and 4 females). During the rainy season (February 2000), we collected 14 specimens (3 males, 10 females, and 1 juvenile). Sex-ratio was 1:1. Frogs ranged in snout-vent length from 31.2 to 69.3 mm. Females were larger than males. One female had 1,451 fully developed oocytes in her ovaries. The major groups of prey found in the stomachs were: Insecta, Myriapoda, and Arachnida. Blattodea, Orthoptera, Lepidoptera, and Hymenoptera (only ants) were the main food types in frequency, number, and weight. Aparasphenodon brunoi is a threatened species in many habitats of southeastern Brazil. Only natural vegetation protection may guarantee its survival during the immediate future.

  10. Phenotypic and molecular variation in the green and black poison-dart frog Dendrobates auratus (Anura: Dendrobatidae from Costa Rica

    Directory of Open Access Journals (Sweden)

    Lisa D Patrick

    2009-11-01

    Full Text Available The green and black poison-dart frog Dendrobates auratus exhibits high intraspecific variation in hue color and pattern throughout its range, making it a very popular species in the pet trade. We analyzed the correspondence between color variation and molecular variation of D. auratus from Costa Rica using RAPD analysis. Twenty-six random primers were analyzed for variation in 99 individuals from seven populations. Color pattern was scored from digital images of the dorsal and ventral views. In general, frogs from the Caribbean coast had significantly more light coloration than black color but cannot be grouped by population based only on hue pattern. Only 3 RAPD primers were found to be polymorphic, representing a total of 16 loci. Most of the molecular variation encountered here occurs within populations, thus making unclear the degree of population structure and differentiation. Further examination of COI mtDNA sequences from our samples also supports these results. Partial Mantel correlations suggested that the pattern of molecular variation is not congruent with the variation in color pattern in this species, an outcome that is discussed in terms of phenotypic evolution. Rev. Biol. Trop. 57 (Suppl. 1: 313-321. Epub 2009 November 30.

  11. Bioacoustic analysis of advertisement call in Hyla nana and Hyla sanborni (Anura, Hylidae in Botucatu, São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Martins I. A.

    2003-01-01

    Full Text Available Vocal communication traits of Hyla nana and Hyla sanborni, of the nana species group, were studied from August 1997 until June 1999 in two large permanent ponds located in an open field in Botucatu, São Paulo State. One hundred thirty-one individuals, 71 of H. nana and 58 of H. sanborni, were recorded in the beginning of their vocalization activity and during chorus vocalization. The rhythms of sound emission on the two occasions were different. An advertisement call consists in a consecutive series of simple notes in rapid succession. Both species have two types of notes in their advertisement calls, here named types A and B. Type A notes are introductory and have a longer and higher pulse number and are emitted more frequently in the beginning of vocalization activity. Introductory notes are the first to be emitted in chorus activity. Type B notes are secondary, of shorter duration and lower pulse number, and are emitted during chorus vocalization. The notes of both types differ significantly in their temporal structure. Both species present acoustic segregation in both spectral and temporal structure.

  12. Systematics of the Dendropsophus leucophyllatus species complex (Anura: Hylidae): Cryptic diversity and the description of two new species

    Science.gov (United States)

    Caminer, Marcel A.; Milá, Borja; Jansen, Martin; Fouquet, Antoine; Venegas, Pablo J.; Chávez, Germán; Lougheed, Stephen C.

    2017-01-01

    Genetic data in studies of systematics of Amazonian amphibians frequently reveal that purportedly widespread single species in reality comprise species complexes. This means that real species richness may be significantly higher than current estimates. Here we combine genetic, morphological, and bioacoustic data to assess the phylogenetic relationships and species boundaries of two Amazonian species of the Dendropsophus leucophyllatus species group: D. leucophyllatus and D. triangulum. Our results uncovered the existence of five confirmed and four unconfirmed candidate species. Among the confirmed candidate species, three have available names: Dendropsophus leucophyllatus, Dendropsophus triangulum, and Dendropsophus reticulatus, this last being removed from the synonymy of D. triangulum. A neotype of D. leucophyllatus is designated. We describe the remaining two confirmed candidate species, one from Bolivia and another from Peru. All confirmed candidate species are morphologically distinct and have much smaller geographic ranges than those previously reported for D. leucophyllatus and D. triangulum sensu lato. Dendropsophus leucophyllatus sensu stricto occurs in the Guianan region. Dendropsophus reticulatus comb. nov. corresponds to populations in the Amazon basin of Brazil, Ecuador, and Peru previously referred to as D. triangulum. Dendropsophus triangulum sensu stricto is the most widely distributed species; it occurs in Amazonian Ecuador, Peru and Brazil, reaching the state of Pará. We provide accounts for all described species including an assessment of their conservation status. PMID:28248998

  13. The occurrence of amphibians in bromeliads from a Southeastern Brazilian restinga habitat, with special reference to Aparasphenodon brunoi (Anura, Hylidae

    Directory of Open Access Journals (Sweden)

    TEIXEIRA R. L.

    2002-01-01

    Full Text Available Five species of anuran amphibians, all belonging to the family Hylidae, were collected at Praia das Neves, municipality of Presidente Kennedy, southeastern Brazil,. The species were represented by four genera: Scinax, Hyla, Aparasphenodon, and Trachycephalus. Four species (A. brunoi, Hyla albomarginata, Scinax altera, and S. cuspidatus were found during the dry season (August 1999, and two (A. brunoi and Trachycephalus nigromaculatus in the rainy season (February 2000. Aparasphenodon brunoi was the most abundant species in Praia das Neves. Some reproductive aspects and feeding habits of this hylid were investigated. Aparasphenodon brunoi was found mainly inside the bromeliad Aechmea lingulata, the largest plant analyzed. Fifteen specimens were collected during the dry season (August 1999 (11 males and 4 females. During the rainy season (February 2000, we collected 14 specimens (3 males, 10 females, and 1 juvenile. Sex-ratio was 1:1. Frogs ranged in snout-vent length from 31.2 to 69.3 mm. Females were larger than males. One female had 1,451 fully developed oocytes in her ovaries. The major groups of prey found in the stomachs were: Insecta, Myriapoda, and Arachnida. Blattodea, Orthoptera, Lepidoptera, and Hymenoptera (only ants were the main food types in frequency, number, and weight. Aparasphenodon brunoi is a threatened species in many habitats of southeastern Brazil. Only natural vegetation protection may guarantee its survival during the immediate future.

  14. The occurrence of amphibians in bromeliads from a Southeastern Brazilian restinga habitat, with special reference to Aparasphenodon brunoi (Anura, Hylidae

    Directory of Open Access Journals (Sweden)

    R. L. TEIXEIRA

    Full Text Available Five species of anuran amphibians, all belonging to the family Hylidae, were collected at Praia das Neves, municipality of Presidente Kennedy, southeastern Brazil,. The species were represented by four genera: Scinax, Hyla, Aparasphenodon, and Trachycephalus. Four species (A. brunoi, Hyla albomarginata, Scinax altera, and S. cuspidatus were found during the dry season (August 1999, and two (A. brunoi and Trachycephalus nigromaculatus in the rainy season (February 2000. Aparasphenodon brunoi was the most abundant species in Praia das Neves. Some reproductive aspects and feeding habits of this hylid were investigated. Aparasphenodon brunoi was found mainly inside the bromeliad Aechmea lingulata, the largest plant analyzed. Fifteen specimens were collected during the dry season (August 1999 (11 males and 4 females. During the rainy season (February 2000, we collected 14 specimens (3 males, 10 females, and 1 juvenile. Sex-ratio was 1:1. Frogs ranged in snout-vent length from 31.2 to 69.3 mm. Females were larger than males. One female had 1,451 fully developed oocytes in her ovaries. The major groups of prey found in the stomachs were: Insecta, Myriapoda, and Arachnida. Blattodea, Orthoptera, Lepidoptera, and Hymenoptera (only ants were the main food types in frequency, number, and weight. Aparasphenodon brunoi is a threatened species in many habitats of southeastern Brazil. Only natural vegetation protection may guarantee its survival during the immediate future.

  15. From Clinging to Digging: The Postembryonic Skeletal Ontogeny of the Indian Purple Frog, Nasikabatrachus sahyadrensis (Anura: Nasikabatrachidae.

    Directory of Open Access Journals (Sweden)

    Gayani Senevirathne

    Full Text Available The Indian Purple frog, Nasikabatrachus sahyadrensis, occupies a basal phylogenetic position among neobatrachian anurans and has a very unusual life history. Tadpoles have a large ventral oral sucker, which they use to cling to rocks in torrents, whereas metamorphs possess adaptations for life underground. The developmental changes that underlie these shifts in habits and habitats, and especially the internal remodeling of the cranial and postcranial skeleton, are unknown. Using a nearly complete metamorphic series from free-living larva to metamorph, we describe the postembryonic skeletal ontogeny of this ancient and unique monotypic lineage. The torrent-dwelling larva possesses a dorsoventrally flattened body and a head with tiny dorsal eyes, robust lower and upper jaw cartilages, well-developed trabecular horns, and a definable gap between the trabecular horns and the tip of the snout. Unlike tadpoles of many other frogs, those of Nasikabatrachus retain larval mouthparts into late metamorphic stages. This unusual feature enables the larvae to maintain their clinging habit until near the end of metamorphosis. The subsequent ontogenetic shift from clinging to digging is correlated with rapid morphological changes and behavioral modifications. Metamorphs are equipped with a shortened tibiafibula and ossified prehallical elements, which likely facilitate initial digging using the hind limbs. Subsequently, the frogs may shift to headfirst burrowing by using the wedge-shaped skull, anteriorly positioned pectoral girdle, well-developed humeral crests and spatula-shaped forelimbs. The transition from an aquatic life in torrents to a terrestrial life underground entails dramatic changes in skeletal morphology and function that represent an extreme in metamorphic remodeling. Our analysis enhances the scope for detailed comparative studies across anurans, a group renowned for the diversity of its life history strategies.

  16. Anomalías oculares en híbridos Bufo paranecmis ♂ x Bufo arenarum ♀ (Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    Rengel, Dora

    1994-01-01

    Full Text Available Los híbridos entre Bufo paracnemis x Bufo arenarum se encuadran en los llamados "híbridos vitales". Los resultados han evidenciado relevantes anomalías oculares que se manifiestan en un 90% de los casos. En algunas larvas falta el cristalino tanto en uno como en ambos ojos (20%; en otras larvas el cristalino se encuentra ubicado en posición opuesta al normal (25% o bien puede ocurrir que se forme un ojo normal y el otro de forma distinta (20%. El análisis histológico mostró anomalías en la zona retiniana, evidenciándose a partir de los estratos pigmentarios, repliegues y movimientos flexuosos (5%. También existen ojos replegados sobre sí mismos (5%. Las alteraciones más severas llevaron a procesos de anoftalmia (10%. En ocasiones (5% en lugar del ojo se evidencian grumos de pigmento. Se obtuvo un 10% con ojos normales. Los otros órganos presentan analogía con los de las larvas de Bufo paracnemis, inclusive la librea dorsal. The hybrids between Bufo paracnemis x Bufo arenarum are counted among tbe so called "vital hybrids". Our results have revealed relevant ocular anomalies in 90% of cases. In some larvae the lens is lacking in either one or both eyes (20%; in others the lens it is found in an opposite position to normal (25% or else one normal and one different eye is formed (20%. Histological analysis reveals anomalies in the retinal area, observing flexuous movements in the pigmentary strata (5%. Eyes folded over themselves were also observed (5%. The most severe alterations produced cases of anophtalmia (10%. On occasions (5%, groupings of pigments were found instead of the eyes. l0% of the larvae were normal. The other organs show analogies to those of the larvae of Bufo paracnemis, including the dorsal pattem.

  17. enriched diets and the growth, development and survival of litoria moorei (anura) tadpoles reared in captivity at low density

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    increasing numbers of amphibian species require conservation breeding programs for their survival.a major challenge is the efficient rearing of tadpoles,many of which require complex habitats and specialised diets.aquatic tadpoles of the west australian frog litoria moorei were kept at low density (1 tadpole per 1.95 litres water) in aquaria at 25℃.fed on a staple diet of boiled lettuce and leaf litter,group of diets were supplemented with either control,wardley(r) premium spirulina discs,seratm gvg-mix tropical fish food,or a combination of wardley(r) premium spirulina discs and seratm gvg-mix fish food.there was a relatively high loss (i.e.,found dead,euthanized due to scoliosis,or not found) of tadpoles fed with the lettuce/leaf litter alone,but this was increased significantly when supplemented with wardley(r) premium spirulina discs,either alone or with seratm gvg-mix fish food,and seratm gvg fish food alone.however,the survived tadpoles fed on the three supplements were all heavier after three weeks and at metamorphosis than those fed with lettuce/leaf litter alone,and reached metamorphosis quicker.it is concluded that any benefit of the food supplements in terms of increasing the rate of growth and development of the tadpoles is outweighed by greater mortality.there is now a need for the efficient rearing of tadpoles,many from novel species that need complex habitats.further studies of diet are required due to the current conservation crisis of amphibians.

  18. Integration of molecular, bioacoustical and morphological data reveals two new cryptic species of Pelodytes (Anura, Pelodytidae) from the Iberian Peninsula.

    Science.gov (United States)

    Díaz-Rodríguez, Jesús; Gehara, Marcelo; Márquez, Rafael; Vences, Miguel; Gonçalves, Helena; Sequeira, Fernando; Martínez-Solano, Iñigo; Tejedo, Miguel

    2017-03-13

    Parsley frogs (Pelodytes) comprise the only genus in the family Pelodytidae, an ancient anuran lineage that split from their closest relatives over 140 million years ago. Pelodytes is a Palearctic group restricted to Western Eurasia including three extant species: the eastern species P. caucasicus, endemic to the Caucasus area, and two closely related species inhabiting Western Europe: the Iberian endemic P. ibericus and the more widespread P. punctatus. Previous studies based on mitochondrial and nuclear DNA markers have revealed the existence of two additional lineages of Parsley frogs in the Iberian Peninsula, which have been flagged as candidate species. Here, we integrate novel molecular, morphological and bioacoustical data to assess the differentiation of the four western Parsley frog lineages. Species trees and Bayesian population assignment analyses based on nuclear markers confirm previous studies and concordantly delineate four parapatric lineages with narrow hybrid zones. Mitochondrial divergence is low (bioacoustical and morphological differentiation of these species is low, with no obvious and qualitative diagnostic characters allowing full species discrimination. Differences in the relative size of metacarpal tubercles exist but this character is variable. Pelodytes ibericus and Pelodytes atlanticus are smaller than the other two species, and P. ibericus has shorter limbs and various distinctive osteological characters. Bioacoustically, the pattern by which two different note types are combined in advertisement calls separates P. hespericus from the remaining species. Despite these differences, we emphasize that the taxonomic status of all four western Parsley frogs requires additional investigation, especially the patterns of genetic admixture across contact zones. While a status of separate species best conforms to the currently available data, alternative hypotheses are also discussed.

  19. Climate change and the distribution of neotropical red-bellied toads (Melanophryniscus, Anura, Amphibia): how to prioritize species and populations?

    Science.gov (United States)

    Zank, Caroline; Becker, Fernando Gertum; Abadie, Michelle; Baldo, Diego; Maneyro, Raúl; Borges-Martins, Márcio

    2014-01-01

    We used species distribution modeling to investigate the potential effects of climate change on 24 species of Neotropical anurans of the genus Melanophryniscus. These toads are small, have limited mobility, and a high percentage are endangered or present restricted geographical distributions. We looked at the changes in the size of suitable climatic regions and in the numbers of known occurrence sites within the distribution limits of all species. We used the MaxEnt algorithm to project current and future suitable climatic areas (a consensus of IPCC scenarios A2a and B2a for 2020 and 2080) for each species. 40% of the species may lose over 50% of their potential distribution area by 2080, whereas 28% of species may lose less than 10%. Four species had over 40% of the currently known occurrence sites outside the predicted 2080 areas. The effect of climate change (decrease in climatic suitable areas) did not differ according to the present distribution area, major habitat type or phylogenetic group of the studied species. We used the estimated decrease in specific suitable climatic range to set a conservation priority rank for Melanophryniscus species. Four species were set to high conservation priority: M. montevidensis, (100% of its original suitable range and all known occurrence points potentially lost by 2080), M. sp.2, M. cambaraensis, and M. tumifrons. Three species (M. spectabilis, M. stelzneri, and M. sp.3) were set between high to intermediate priority (more than 60% decrease in area predicted by 2080); nine species were ranked as intermediate priority, while eight species were ranked as low conservation priority. We suggest that monitoring and conservation actions should be focused primarily on those species and populations that are likely to lose the largest area of suitable climate and the largest number of known populations in the short-term.

  20. Climate change and the distribution of neotropical red-bellied toads (Melanophryniscus, Anura, Amphibia: how to prioritize species and populations?

    Directory of Open Access Journals (Sweden)

    Caroline Zank

    Full Text Available We used species distribution modeling to investigate the potential effects of climate change on 24 species of Neotropical anurans of the genus Melanophryniscus. These toads are small, have limited mobility, and a high percentage are endangered or present restricted geographical distributions. We looked at the changes in the size of suitable climatic regions and in the numbers of known occurrence sites within the distribution limits of all species. We used the MaxEnt algorithm to project current and future suitable climatic areas (a consensus of IPCC scenarios A2a and B2a for 2020 and 2080 for each species. 40% of the species may lose over 50% of their potential distribution area by 2080, whereas 28% of species may lose less than 10%. Four species had over 40% of the currently known occurrence sites outside the predicted 2080 areas. The effect of climate change (decrease in climatic suitable areas did not differ according to the present distribution area, major habitat type or phylogenetic group of the studied species. We used the estimated decrease in specific suitable climatic range to set a conservation priority rank for Melanophryniscus species. Four species were set to high conservation priority: M. montevidensis, (100% of its original suitable range and all known occurrence points potentially lost by 2080, M. sp.2, M. cambaraensis, and M. tumifrons. Three species (M. spectabilis, M. stelzneri, and M. sp.3 were set between high to intermediate priority (more than 60% decrease in area predicted by 2080; nine species were ranked as intermediate priority, while eight species were ranked as low conservation priority. We suggest that monitoring and conservation actions should be focused primarily on those species and populations that are likely to lose the largest area of suitable climate and the largest number of known populations in the short-term.

  1. From Clinging to Digging: The Postembryonic Skeletal Ontogeny of the Indian Purple Frog, Nasikabatrachus sahyadrensis (Anura: Nasikabatrachidae).

    Science.gov (United States)

    Senevirathne, Gayani; Thomas, Ashish; Kerney, Ryan; Hanken, James; Biju, S D; Meegaskumbura, Madhava

    2016-01-01

    The Indian Purple frog, Nasikabatrachus sahyadrensis, occupies a basal phylogenetic position among neobatrachian anurans and has a very unusual life history. Tadpoles have a large ventral oral sucker, which they use to cling to rocks in torrents, whereas metamorphs possess adaptations for life underground. The developmental changes that underlie these shifts in habits and habitats, and especially the internal remodeling of the cranial and postcranial skeleton, are unknown. Using a nearly complete metamorphic series from free-living larva to metamorph, we describe the postembryonic skeletal ontogeny of this ancient and unique monotypic lineage. The torrent-dwelling larva possesses a dorsoventrally flattened body and a head with tiny dorsal eyes, robust lower and upper jaw cartilages, well-developed trabecular horns, and a definable gap between the trabecular horns and the tip of the snout. Unlike tadpoles of many other frogs, those of Nasikabatrachus retain larval mouthparts into late metamorphic stages. This unusual feature enables the larvae to maintain their clinging habit until near the end of metamorphosis. The subsequent ontogenetic shift from clinging to digging is correlated with rapid morphological changes and behavioral modifications. Metamorphs are equipped with a shortened tibiafibula and ossified prehallical elements, which likely facilitate initial digging using the hind limbs. Subsequently, the frogs may shift to headfirst burrowing by using the wedge-shaped skull, anteriorly positioned pectoral girdle, well-developed humeral crests and spatula-shaped forelimbs. The transition from an aquatic life in torrents to a terrestrial life underground entails dramatic changes in skeletal morphology and function that represent an extreme in metamorphic remodeling. Our analysis enhances the scope for detailed comparative studies across anurans, a group renowned for the diversity of its life history strategies.

  2. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    Communications Infrastructure The 55 CMS Centres worldwide are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin is particularly busy at the moment, hosting about 50 physicists taking part in the heavy-ion data-taking and analysis. Three new CMS meeting room will be equipped for videoconferencing in early 2012: 40/5B-08, 42/R-031, and 28/S-029. The CMS-TV service showing LHC Page 1, CMS Page 1, etc. (http://cmsdoc.cern.ch/cmscc/projector/index.jsp) is now also available for mobile devices: http://cern.ch/mcmstv. Figure 12: Screenshots of CMS-TV for mobile devices Information Systems CMS has a new web site: (http://cern.ch/cms) using a modern web Content Management System to ensure content and links are managed and updated easily and coherently. It covers all CMS sub-projects and groups, replacing the iCMS internal pages. It also incorporates the existing CMS public web site (http:/...

  3. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2012-01-01

      Outreach and Education We are fortunate that our research has captured the public imagination, even though this inevitably puts us under the global media spotlight, as we saw with the Higgs seminar at CERN in December, which had 110,000 distinct webcast viewers. The media interest was huge with 71 media organisations registering to come to CERN to cover the Higgs seminar, which was followed by a press briefing with the DG and Spokespersons. This event resulted in about 2,000 generally positive stories in the global media. For this seminar, the CMS Communications Group prepared up-to-date news and public material, including links to the CMS results, animations and event displays [http://cern.ch/go/Ch8thttp://cern.ch/go/Ch8t]. There were 44,000 page-views on the CMS public website, with the Higgs news article being by far the most popular item. CMS event displays from iSpy are fast becoming the iconic media images, featuring on numerous major news outlets (BBC, CNN, MSN...) as well as in the sci...

  4. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2010-01-01

    The recently established CMS Communications Group, led by Lucas Taylor, has been busy in all three of its main are areas of responsibility: Communications Infrastructure, Information Systems, and Outreach and Education Communications Infrastructure The damage caused by the flooding of the CMS Centre@CERN on 21st December has been completely repaired and all systems are back in operation. Major repairs were made to the roofs, ceilings and one third of the floor had to be completely replaced. Throughout these works, the CMS Centre was kept operating and even hosted a major press event for first 7 TeV collisions, as described below. Incremental work behind the scenes is steadily improving the quality of the CMS communications infrastructure, particularly Webcasting, video conferencing, and meeting rooms at CERN. CERN/IT is also deploying a pilot service of a new videoconference tool called Vidyo, to assess whether it might provide an enhanced service at a lower cost, compared to the EVO tool currently in w...

  5. From mapping class groups to automorphism groups of free groups

    DEFF Research Database (Denmark)

    Wahl, Nathalie

    2005-01-01

    We show that the natural map from the mapping class groups of surfaces to the automorphism groups of free groups, induces an infinite loop map on the classifying spaces of the stable groups after plus construction. The proof uses automorphisms of free groups with boundaries which play the role...... of mapping class groups of surfaces with several boundary components....

  6. The evolution of jumping in frogs: morphological evidence for the basal anuran locomotor condition and the radiation of locomotor systems in crown group anurans.

    Science.gov (United States)

    Reilly, Stephen M; Jorgensen, Michael E

    2011-02-01

    Our understanding of the evolution of frog locomotion follows from the work of Emerson in which anurans are proposed to possess one of three different iliosacral configurations: 1) a lateral-bending system found in walking and hopping frogs; 2) a fore-aft sliding mechanism found in several locomotor modes; and 3) a sagittal-hinge-type pelvis posited to be related to long-distance jumping performance. The most basal living (Ascaphus) and fossil (Prosalirus) frogs are described as sagittal-hinge pelvic types, and it has been proposed that long-distance jumping with a sagittal-hinge pelvis arose early in frog evolution. We revisited osteological traits of the pelvic region to conduct a phylogenetic analysis of the relationships between pelvic systems and locomotor modes in frogs. Using two of Emerson's diagnostic traits from the sacrum and ilium and two new traits from the urostyle, we resampled the taxa originally studied by Emerson and key paleotaxa and conducted an analysis of ancestral-character state evolution in relation to locomotor mode. We present a new pattern for the evolution of pelvic systems and locomotor modes in frogs. Character analysis shows that the lateral-bender, walker/hopper condition is both basal and generally conserved across the Anura. Long-distance jumping frogs do not appear until well within the Neobatrachia. The sagittal-hinge morphology is correlated with long-distance jumping in terrestrial frogs; however, it evolved convergently multiple times in crown group anurans with the same four pelvic traits described herein. Arboreal jumping has appeared in multiple crown lineages as well, but with divergent patterns of evolution involving each of the three pelvic types. The fore-aft slider morph appears independently in three different locomotor modes and, thus, is a more complex system than previously thought. Finally, it appears that the advent of a bicondylar sacro-urostylic articulation was originally related to providing axial rigidity

  7. Diversidade e ocorrência temporal da anurofauna (Amphibia, Anura em São José dos Pinhais, Paraná, Brasil Diversity and seasonal occurrence of anurans in São José dos Pinhais, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Carlos E. Conte

    2006-03-01

    Full Text Available A Floresta Atlântica é o bioma com a maior diversidade e taxa de endemismo de anfíbios anuros do mundo. Entretanto, informações sobre a história natural e os padrões de ocorrência das espécies são, em grande parte, ainda desconhecidas para esse bioma. No presente estudo, a diversidade e a ocorrência temporal de espécies de anuros foram determinadas em área de ecótono entre Floresta Ombrófila Densa e Floresta Ombrófila Mista no estado do Paraná, sul do Brasil. No levantamento, realizado entre janeiro de 2003 e maio de 2004, foram registradas 34 espécies de cinco famílias: Bufonidae (duas espécies, Hylidae (17 espécies, Leptodactylidae (13 espécies, Microhylidae (uma espécie e Ranidae (uma espécie. A riqueza registrada é uma das maiores do Paraná e oito, dos nove hábitats amostrados, apresentaram alta diversidade de espécies. Isso pode ser decorrente do fato da área estudada estar localizada em região de ecótono, o que favoreceu a ocorrência de espécies típicas de cada formação vegetal. Além disso, uma hipótese adicional é a do distúrbio intermediário, decorrente do desmatamento ocorrido até trinta anos atrás, que possibilitou a ocorrência de algumas espécies típicas de áreas abertas. Machos da maioria das espécies (48% vocalizaram no período chuvoso e quente do ano, mas a proporção de espécies anuais (25% foi grande, semelhante à encontrada em regiões com clima tropical úmido (30%. A similaridade na composição de espécies de nove localidades no Paraná foi associada à fisionomia vegetal das áreas amostradas.The Atlantic Forest is the biome with the largest biodiversity and endemism rate of anuran amphibians in the world. However, information on natural history and patterns of occurrence are still unknown for most of the species that occur in this biome. In this study the diversity and the seasonal occurrence of anuran amphibians were determined in an ecotone area between Atlantic Forest

  8. Integrated Groups and Smooth Distribution Groups

    Institute of Scientific and Technical Information of China (English)

    Pedro J. MIANA

    2007-01-01

    In this paper, we prove directly that α-times integrated groups define algebra homo-morphisms. We also give a theorem of equivalence between smooth distribution groups and α-times integrated groups.

  9. Group typicality, group loyalty and cognitive development.

    Science.gov (United States)

    Patterson, Meagan M

    2014-09-01

    Over the course of childhood, children's thinking about social groups changes in a variety of ways. Developmental Subjective Group Dynamics (DSGD) theory emphasizes children's understanding of the importance of conforming to group norms. Abrams et al.'s study, which uses DSGD theory as a framework, demonstrates the social cognitive skills underlying young elementary school children's thinking about group norms. Future research on children's thinking about groups and group norms should explore additional elements of this topic, including aspects of typicality beyond loyalty.

  10. Which finite simple groups are unit groups?

    DEFF Research Database (Denmark)

    Davis, Christopher James; Occhipinti, Tommy

    2014-01-01

    We prove that if G is a finite simple group which is the unit group of a ring, then G is isomorphic to either (a) a cyclic group of order 2; (b) a cyclic group of prime order 2^k −1 for some k; or (c) a projective special linear group PSLn(F2) for some n ≥ 3. Moreover, these groups do all occur...

  11. Group Cohesion in Experiential Growth Groups

    Science.gov (United States)

    Steen, Sam; Vasserman-Stokes, Elaina; Vannatta, Rachel

    2014-01-01

    This article explores the effect of web-based journaling on changes in group cohesion within experiential growth groups. Master's students were divided into 2 groups. Both used a web-based platform to journal after each session; however, only 1 of the groups was able to read each other's journals. Quantitative data collected before and…

  12. Group Work Publication-1991.

    Science.gov (United States)

    Zimpfer, David G.

    1992-01-01

    Lists 21 new publications in group work, of which 9 are reviewed. Those discussed include publications on group counseling and psychotherapy, structured groups, support groups, psychodrama, and social group work. (Author/NB)

  13. Group theories: relevance to group safety studies.

    Science.gov (United States)

    Benevento, A L

    1998-01-01

    Promoting safety in the workplace has been attempted in a variety of ways. Increasingly, industries are using groups such as safety teams and quality circles to promote worker safety. Group influences on individual behavior and attitudes have long been studied in the social psychology literature, but the theories have not been commonly found outside the psychology arena. This paper describes the group theories of group polarization, risky shift, social loafing, groupthink and team think and attempts to apply these theories to existing studies that examine work group influences on safety. Interesting parallels were found but only one study examined group influences as their primary focus of research. Since groups are increasingly used for safety promotion, future research on safety that studies group influences with respect to current group theories is recommended.

  14. Hematología y citoquímica de las células sanguíneas de Rhinella fernandezae (Anura: Bufonidae en Espinal y Delta-Islas del río Paraná, Argentina

    Directory of Open Access Journals (Sweden)

    Mariana C Cabagna Zenklusen

    2011-03-01

    Full Text Available La descripción de la hematología de los anfibios anuros es escasa, habiéndose realizado la mayoría de los trabajos en especies de Norteamérica, Asia y Europa. Con el propósito de obtener datos hematológicos para Rhinella fernandezae, fueron estudiados 23 especímenes provenientes de zonas protegidas de las provincias de Santa Fe y Entre Ríos. Se les extrajo sangre por punción cardíaca y se realizaron hemogramas. En los extendidos sanguíneos, se efectuaron la descripción morfológica y citoquímica de las células sanguíneas y búsqueda de parásitos. Se observaron cinco tipos de leucocitos, donde predominaron los linfocitos pequeños. Heterófilos y eosinófilos resultaron positivos para PAS, Sudan B y peroxidasa; contrariamente, los eritrocitos y sus precursores fueron negativos. Los puntajes de las reacciones citoquímicas fueron variables para basófilos, linfocitos, monocitos y trombocitos. Las frecuencias de micronúcleos y de alteraciones nucleares fueron escasas. No se observaron diferencias significativas (p>0.05 entre sexos en el hemograma ni en la morfología sanguínea. Los únicos hemoparásitos encontrados fueron microfilarias (Nematoda: Filaroidea, cuya prevalencia e intensidad de infección fueron bajas. Las características hematológicas estudiadas fueron semejantes a los valores reportados para otros anfibios, pudiendo inferir que los individuos de R. fernandezae estudiados se encuentran en un buen estado nutricional e inmunológico.Hematology and blood cell cytochemistry of Rhinella fernandezae (Amphibia: Anura from Espinal and Delta-Islands of Paraná River, Argentina. The description of amphibian hematology is scarce and most of these studies have been done in species from North America, Asia and Europe. With the purpose to obtain basic hematological information of Rhinella fernandezae, 23 blood samples from Santa Fe and Entre Ríos natural reserves were studied. Blood of each individual was extracted by cardiac

  15. Magnetic translation groups as group extension

    OpenAIRE

    Florek, Wojciech

    1998-01-01

    Extensions of a direct product T of two cyclic groups Z_n1 and Z_n2 by an Abelian (gauge) group G with the trivial action of T on G are considered. All possible (nonequivalent) factor systems are determined using the Mac Lane method. Some of resulting groups describe magnetic translation groups. As examples extensions with G=U(1) and G=Z_n are considered and discussed.

  16. Group Dynamic Processes in Email Groups

    Science.gov (United States)

    Alpay, Esat

    2005-01-01

    Discussion is given on the relevance of group dynamic processes in promoting decision-making in email discussion groups. General theories on social facilitation and social loafing are considered in the context of email groups, as well as the applicability of psychodynamic and interaction-based models. It is argued that such theories may indeed…

  17. Interagency mechanical operations group numerical systems group

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    This report consists of the minutes of the May 20-21, 1971 meeting of the Interagency Mechanical Operations Group (IMOG) Numerical Systems Group. This group looks at issues related to numerical control in the machining industry. Items discussed related to the use of CAD and CAM, EIA standards, data links, and numerical control.

  18. AREVA group overview; Presentation du groupe AREVA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-02-08

    This document presents the Group Areva, a world nuclear industry leader, from a financial holding company to an industrial group, operating in two businesses: the nuclear energy and the components. The structure and the market of the group are discussed, as the financial assets. (A.L.B.)

  19. About group digital signatures

    National Research Council Canada - National Science Library

    Adriana Cristina Enache

    2012-01-01

    ...).A group digital signature is a digital signature with enhanced privacy features that allows members of a given group to anonymously sign messages on behalf of the group, producing a group signature...

  20. Introduction to Sporadic Groups

    Directory of Open Access Journals (Sweden)

    Luis J. Boya

    2011-01-01

    Full Text Available This is an introduction to finite simple groups, in particular sporadic groups, intended for physicists. After a short review of group theory, we enumerate the 1+1+16=18 families of finite simple groups, as an introduction to the sporadic groups. These are described next, in three levels of increasing complexity, plus the six isolated ''pariah'' groups. The (old five Mathieu groups make up the first, smallest order level. The seven groups related to the Leech lattice, including the three Conway groups, constitute the second level. The third and highest level contains the Monster group M, plus seven other related groups. Next a brief mention is made of the remaining six pariah groups, thus completing the 5+7+8+6=26 sporadic groups. The review ends up with a brief discussion of a few of physical applications of finite groups in physics, including a couple of recent examples which use sporadic groups.

  1. Group Work: How to Use Groups Effectively

    Science.gov (United States)

    Burke, Alison

    2011-01-01

    Many students cringe and groan when told that they will need to work in a group. However, group work has been found to be good for students and good for teachers. Employers want college graduates to have developed teamwork skills. Additionally, students who participate in collaborative learning get better grades, are more satisfied with their…

  2. Small Group Research

    Science.gov (United States)

    McGrath, Joseph E.

    1978-01-01

    Summarizes research on small group processes by giving a comprehensive account of the types of variables primarily studied in the laboratory. These include group structure, group composition, group size, and group relations. Considers effects of power, leadership, conformity to social norms, and role relationships. (Author/AV)

  3. Free Boolean Topological Groups

    Directory of Open Access Journals (Sweden)

    Ol’ga Sipacheva

    2015-11-01

    Full Text Available Known and new results on free Boolean topological groups are collected. An account of the properties that these groups share with free or free Abelian topological groups and properties specific to free Boolean groups is given. Special emphasis is placed on the application of set-theoretic methods to the study of Boolean topological groups.

  4. A new species of Hyla (Anura: Hylidae) from the Sierra Mixes, Oaxaca, Mexico, with comments on ontogenetic variation in the tadpoles

    Science.gov (United States)

    Ustach, P.C.; Mendelson, J.R.; McDiarmid, R.W.; Campbell, J.A.

    2000-01-01

    We describe a new species of Hyla that differs from the similar-loohng species H. pentheter by reaching a larger size, ha\\iing a smaller tympanum, more webbing on the feet, more extensive nuptial excrescences, and a different color pattern on the flanks. \\Ve tentatively place this new species in the phenetic assemblage commonly referred to as the H. bistincta group. \\Ve describe and illlistrate the tadpole and discuss ontogenetic variation among tadpoles, with reference to existing information on tadpoles of other species from the H. bistincta group.

  5. MSUD Family Support Group

    Science.gov (United States)

    ... Group The MSUD Family Support Group is a non-profit 501 (c)(3) organization for those with MSUD ... Family Support Group is a 501(c)(3) non-profit organization with no paid staff. Funds are needed ...

  6. Profinite graphs and groups

    CERN Document Server

    Ribes, Luis

    2017-01-01

    This book offers a detailed introduction to graph theoretic methods in profinite groups and applications to abstract groups. It is the first to provide a comprehensive treatment of the subject. The author begins by carefully developing relevant notions in topology, profinite groups and homology, including free products of profinite groups, cohomological methods in profinite groups, and fixed points of automorphisms of free pro-p groups. The final part of the book is dedicated to applications of the profinite theory to abstract groups, with sections on finitely generated subgroups of free groups, separability conditions in free and amalgamated products, and algorithms in free groups and finite monoids. Profinite Graphs and Groups will appeal to students and researchers interested in profinite groups, geometric group theory, graphs and connections with the theory of formal languages. A complete reference on the subject, the book includes historical and bibliographical notes as well as a discussion of open quest...

  7. Homomorphisms of quantum groups

    CERN Document Server

    Meyer, Ralf; Woronowicz, Stanisław Lech

    2010-01-01

    We introduce some equivalent notions of homomorphisms between quantum groups that behave well with respect to duality of quantum groups. Our equivalent definitions are based on bicharacters, coactions, and universal quantum groups, respectively.

  8. Food Groups Recipes

    OpenAIRE

    2012-01-01

    15 pages In 2011, My Plate replaced the Food Pyramid as a visual representation for the USDA Dietary Guidelines. This publication, a group of recipes based on this new division of food groups, reflects the effort of the USDA and other groups to translate science-based research into everyday practice for Americans. Fifteen recipes (3 from each food group) show ways to use foods from each food group. They are complete with basic nutritional analyses and food group amounts.

  9. On The Identity Of Some Toads Of The Genus Bufo From Ecuador, With Additional Remarks On Andinophryne Colomai Hoogmoed, 1985 (Amphibia: Anura: Bufonidae).

    NARCIS (Netherlands)

    Hoogmoed, M.S.

    1989-01-01

    Study of the type specimens of B. caeruleostictus Günther, 1859 and B. chanchanensis Fowler, 1913, and of fresh material showed that B. chanchanensis is a junior subjective synonym of B. caeruleostictus. Probably it is a member of the B. guttatus group. B. caeruleocellatus Fowler, 1913 is a junior s

  10. Locally minimal topological groups

    OpenAIRE

    Außenhofer, Lydia; Chasco, María Jesús; Dikranjan, Dikran; Domínguez, Xabier

    2009-01-01

    A Hausdorff topological group $(G,\\tau)$ is called locally minimal if there exists a neighborhood $U$ of 0 in $\\tau$ such that $U$ fails to be a neighborhood of zero in any Hausdorff group topology on $G$ which is strictly coarser than $\\tau.$ Examples of locally minimal groups are all subgroups of Banach-Lie groups, all locally compact groups and all minimal groups. Motivated by the fact that locally compact NSS groups are Lie groups, we study the connection between local minimality and the ...

  11. GROUP PROFILE Computer Technique

    Directory of Open Access Journals (Sweden)

    Andrey V. Sidorenkov

    2015-01-01

    Full Text Available This article contains a description of the structure, the software and functional capabilities, and the scope and purposes of application of the Group Profile (GP computer technique. This technique rests on a conceptual basis (the microgroup theory, includes 16 new and modified questionnaires, and a unique algorithm, tied to the questionnaires, for identification of informal groups. The GP yields a wide range of data about the group as a whole (47 indices, each informal group (43 indices, and each group member (16 indices. The GP technique can be used to study different types of groups: production (work groups, design teams, military units, etc., academic (school classes, student groups, and sports.

  12. Ordered groups and infinite permutation groups

    CERN Document Server

    1996-01-01

    The subjects of ordered groups and of infinite permutation groups have long en­ joyed a symbiotic relationship. Although the two subjects come from very different sources, they have in certain ways come together, and each has derived considerable benefit from the other. My own personal contact with this interaction began in 1961. I had done Ph. D. work on sequence convergence in totally ordered groups under the direction of Paul Conrad. In the process, I had encountered "pseudo-convergent" sequences in an ordered group G, which are like Cauchy sequences, except that the differences be­ tween terms of large index approach not 0 but a convex subgroup G of G. If G is normal, then such sequences are conveniently described as Cauchy sequences in the quotient ordered group GIG. If G is not normal, of course GIG has no group structure, though it is still a totally ordered set. The best that can be said is that the elements of G permute GIG in an order-preserving fashion. In independent investigations around that t...

  13. The advertisement and aggressive calls of Rhinella abei (Baldissera, Caramaschi, and Haddad, 2004) (Anura: Bufonidae) from Campo Largo, Paraná, Brazil.

    Science.gov (United States)

    Batista, Vinicius Guerra; Ramalho, Werther Pereira; Amaral, Diogo Ferreira Do; Maciel, Natan Medeiros; Bastos, Rogério Pereira

    2016-05-04

    Rhinella abei is a medium-sized species (snout-to-vent length 57.0-76.4 mm in males; 60.4-83.9 mm in females-Baldissera et al. 2004) of the Rhinella crucifer species group, distributed in the Brazilian Atlantic Rainforest, from the State of Paraná to northern Rio Grande do Sul (Frost 2016). It is recorded in forested areas (Conte & Rossa-Feres 2007), or while breeding along forest edges and open habitats. Information on advertisement calls of species in the R. crucifer group is available for R. casconi, R. crucifer, R. inopina and R. ornata (Andrade et al. 2015; Heyer et al. 1990; Oliveira et al. 2014; Roberto et al. 2014). Here we describe the advertisement and aggressive calls of R. abei recorded in the municipality of Campo Largo (25.507472° S, 49.376632° W, datum "WGS84"), southeast State of Paraná, Brazil.

  14. The advertisement call and comments on the distribution of Eleutherodactylus bilineatus Bokermann, 1975, an endemic frog of Bahia State, Brazil (Amphibia, Anura).

    Science.gov (United States)

    Dias, Iuri Ribeiro; de Mira-Mendes, Caio Vinicius; Souza-Costa, Carlos Augusto; Juncá, Flora Acuña; Solé, Mirco

    2017-01-01

    Advertisement calls can be used to aid solving taxonomic problems and understanding the evolution of certain groups. In this study, the advertisement call of Eleutherodactylus bilineatus is described. It is composed by two different notes with a total duration of 0.529-4.241 seconds and dominant frequency of 1.72-3.45 kHz. Additionally, new data is provided on the geographical distribution of Eleutherodactylus bilineatus and the most inland record for this species.

  15. Communication in Organizational Groups

    OpenAIRE

    Monica RADU

    2007-01-01

    Organizational group can be defined as some persons between who exist interactive connections (functional, communication, affective, normative type). Classification of these groups can reflect the dimension, type of relationship or type of rules included. Organizational groups and their influence over the individual efficiency and the efficiency of the entire group are interconnected. Spontaneous roles in these groups sustain the structure of the relationship, and the personality of each indi...

  16. The Great American Biotic Interchange in frogs: multiple and early colonization of Central America by the South American genus Pristimantis (Anura: Craugastoridae).

    Science.gov (United States)

    Pinto-Sánchez, Nelsy Rocío; Ibáñez, Roberto; Madriñán, Santiago; Sanjur, Oris I; Bermingham, Eldredge; Crawford, Andrew J

    2012-03-01

    The completion of the land bridge between North and South America approximately 3.5-3.1 million years ago (Ma) initiated a tremendous biogeographic event called the Great American Biotic Interchange (GABI), described principally from the mammalian fossil record. The history of biotic interchange between continents for taxonomic groups with poor fossil records, however, is not well understood. Molecular and fossil data suggest that a number of plant and animal lineages crossed the Isthmus of Panama well before 3.5 Ma, leading biologists to speculate about trans-oceanic dispersal mechanisms. Here we present a molecular phylogenetic analysis of the frog genus Pristimantis based on 189 individuals of 137 species, including 71 individuals of 31 species from Panama and Colombia. DNA sequence data were obtained from three mitochondrial (COI, 12S, 16S) and two nuclear (RAG-1 and Tyr) genes, for a total of 4074 base pairs. The resulting phylogenetic hypothesis showed statistically significant conflict with most recognized taxonomic groups within Pristimantis, supporting only the rubicundus Species Series, and the Pristimantis myersi and Pristimantis pardalis Species Groups as monophyletic. Inference of ancestral areas based on a likelihood model of geographic range evolution via dispersal, local extinction, and cladogenesis (DEC) suggested that the colonization of Central America by South American Pristimantis involved at least 11 independent events. Relaxed-clock analyses of divergence times suggested that at least eight of these invasions into Central America took place prior to 4 Ma, mainly in the Miocene. These findings contribute to a growing list of molecular-based biogeographic studies presenting apparent temporal conflicts with the traditional GABI model.

  17. The advertisement call and comments on the distribution of Eleutherodactylus bilineatus Bokermann, 1975, an endemic frog of Bahia State, Brazil (Amphibia, Anura

    Directory of Open Access Journals (Sweden)

    Iuri Ribeiro Dias

    2017-05-01

    Full Text Available Advertisement calls can be used to aid solving taxonomic problems and understanding the evolution of certain groups. In this study, the advertisement call of Eleutherodactylus bilineatus is described. It is composed by two different notes with a total duration of 0.529–4.241 seconds and dominant frequency of 1.72–3.45 kHz. Additionally, new data is provided on the geographical distribution of Eleutherodactylus bilineatus and the most inland record for this species.

  18. Group Psychotherapy in Iceland.

    Science.gov (United States)

    Ívarsson, Ómar

    2015-10-01

    In this overview of group psychotherapy in Iceland, an attempt will be made to describe how it is practiced today, give some glimpses into its earlier history, and clarify seven issues: (1) the standing of group psychotherapy in Iceland, its previous history, and the theoretical orientation of dynamic group therapy in the country; (2) the role of group therapy in the health care system; (3) how training in group therapy is organized; (4) the relationship between group psychotherapy research and clinical practice; (5) which issues/processes can be identified as unique to therapy groups in Iceland; and (6) how important are group-related issues within the social background of the country; and (7) what group work holds for the future.

  19. Locally minimal topological groups

    CERN Document Server

    enhofer, Lydia Au\\ss; Dikranjan, Dikran; Domínguez, Xabier

    2009-01-01

    A Hausdorff topological group $(G,\\tau)$ is called locally minimal if there exists a neighborhood $U$ of 0 in $\\tau$ such that $U$ fails to be a neighborhood of zero in any Hausdorff group topology on $G$ which is strictly coarser than $\\tau.$ Examples of locally minimal groups are all subgroups of Banach-Lie groups, all locally compact groups and all minimal groups. Motivated by the fact that locally compact NSS groups are Lie groups, we study the connection between local minimality and the NSS property, establishing that under certain conditions, locally minimal NSS groups are metrizable. A symmetric subset of an abelian group containing zero is said to be a GTG set if it generates a group topology in an analogous way as convex and symmetric subsets are unit balls for pseudonorms on a vector space. We consider topological groups which have a neighborhood basis at zero consisting of GTG sets. Examples of these locally GTG groups are: locally pseudo--convex spaces, groups uniformly free from small subgroups (...

  20. First evidence of the effects of agricultural activities on gonadal form and function in Rhinella fernandezae and Dendropsophus sanborni (Amphibia: Anura from Entre Ríos Province, Argentina

    Directory of Open Access Journals (Sweden)

    Laura C. Sanchez

    2014-06-01

    Full Text Available The relationship between male gonadal abnormalities and habitats with different degrees of agricultural activities was quantified in two anuran species, Rhinella fernandezae and Dendropsophus sanborni. The study sites were selected along a gradient of increasing agricultural land use in south-western Entre Ríos province (Argentina: an agroecosystem, a natural wetland (a non-agricultural site adjacent to monoculture zones, and a natural forest (not associated with agriculture. Rhinella fernandezae and D. sanborni were manually captured from each environment during field surveys. A scaled mass index (MI was evaluated for each animal. Specimens of R. fernandezae from the agroecosystem and the natural wetland site presented poorly developed seminiferous tubules, lower testicular volume, and a lower number of seminiferous tubules, primary spermatogonia, and spermatids than specimens from the natural forest site. Additionally, we observed fewer primary spermatocytes in the agroecosystem group than in the natural forest group. Individuals of D. sanborni from the agroecosystem and the natural wetland site presented poorly developed tubules, higher proportions of irregularly shaped testes, and a reduced number of primary and secondary spermatogonia compared with specimens from natural forest sites. Consequently, the affected anurans are likely to have reduced reproductive success. We suggest that agrochemical use may be associated with decreased testicular development and function in both R. fernandezae and D. sanborni occurring in agroecosystems and nearby environments. Buffer zones are needed to prevent contamination, preserve wildlife, and enhance the conservation value of pristine natural forests.

  1. A new red-eyed treefrog of Agalychnis (Anura: Hylidae: Phyllomedusinae) from middle Magdalena River valley of Colombia with comments on its phylogenetic position.

    Science.gov (United States)

    Rivera-Correa, Mauricio; Duarte-Cubides, Felipe; Rueda-Almonacid, José Vicente; Daza, Juan M

    2013-01-01

    We describe a new species of the charismatic red-eyed treefrogs (genus Agalychnis) from middle Magdalena River valley of Colombia (05°50'8.04"N, 74°50'16.55"W, 380 m a.s.l.). The new species is readily distinguished from all species members of the group by having orange flanks with small white warts. Phylogenetic analysis of DNA sequences of 16S rRNA gene recovered the new species as a member of the Agalychnis callidryas group. The presence of a red hue in the iris and a golden reticulated palpebral membrane, putative synapomorphies of the clade, support this hypothesis. Our analysis suggests that Agalychnis terranova sp. nov is closely related to A. callidryas from Central America and is proposed as its sister species with an uncorrected genetic distance of 5.69% between these taxa. The phylogenetic position and the geographic distribution of the new taxon add new lights to the presence of a biogeographic disjunction between Middle America lowlands, the Pacific region and Magdalena River valley of Colombia.

  2. Higher arithmetic Chow groups

    CERN Document Server

    Gil, J I Burgos

    2009-01-01

    We give a new construction of higher arithmetic Chow groups for quasi-projective arithmetic varieties over a field. Our definition agrees with the higher arithmetic Chow groups defined by Goncharov for projective arithmetic varieties over a field. These groups are the analogue, in the Arakelov context, of the higher algebraic Chow groups defined by Bloch. The degree zero group agrees with the arithmetic Chow groups of Burgos. Our new construction is shown to be a contravariant functor and is endowed with a product structure, which is commutative and associative.

  3. Working with Groups.

    Science.gov (United States)

    Morris, Joan, Ed.

    1984-01-01

    Describes nine Canadian programs for counseling groups of students. Topics include introducing computer-assisted guidance, future challenges for counselors, sociometry, sexuality, parent counseling, reluctant students, shyness, peer groups, education for living, and guidance advisory committees. (JAC)

  4. Gestalt Interactional Groups

    Science.gov (United States)

    Harman, Robert L.; Franklin, Richard W.

    1975-01-01

    Gestalt therapy in groups is not limited to individual work in the presence of an audience. Describes several ways to involve gestalt groups interactionally. Interactions described focus on learning by doing and discovering, and are noninterpretive. (Author/EJT)

  5. Group B streptococcus - pregnancy

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000511.htm Group B streptococcus - pregnancy To use the sharing features on this page, please enable JavaScript. Group B streptococcus (GBS) is a type of bacteria that ...

  6. Group Decision Process Support

    DEFF Research Database (Denmark)

    Gøtze, John; Hijikata, Masao

    1997-01-01

    Introducing the notion of Group Decision Process Support Systems (GDPSS) to traditional decision-support theorists.......Introducing the notion of Group Decision Process Support Systems (GDPSS) to traditional decision-support theorists....

  7. About group digital signatures

    Directory of Open Access Journals (Sweden)

    Adriana Cristina Enache

    2012-09-01

    Full Text Available

    Group signatures try to combine security (no framing, no cheating and privacy(anonymity, unlinkability.A group digital signature is a digital signature with enhanced privacy features that allows members of a given group to anonymously sign messages on behalf of the group, producing a group signature. However, in the case of dispute the identity of the signature's originator can be revealed by a designated entity (group manager. The present paper describes the main concepts about group signatures, along with a brief state of the art and shows a personal cryptographic library implemented in Java that includes two group signatures.

  8. Fast Overlapping Group Lasso

    CERN Document Server

    Liu, Jun

    2010-01-01

    The group Lasso is an extension of the Lasso for feature selection on (predefined) non-overlapping groups of features. The non-overlapping group structure limits its applicability in practice. There have been several recent attempts to study a more general formulation, where groups of features are given, potentially with overlaps between the groups. The resulting optimization is, however, much more challenging to solve due to the group overlaps. In this paper, we consider the efficient optimization of the overlapping group Lasso penalized problem. We reveal several key properties of the proximal operator associated with the overlapping group Lasso, and compute the proximal operator by solving the smooth and convex dual problem, which allows the use of the gradient descent type of algorithms for the optimization. We have performed empirical evaluations using the breast cancer gene expression data set, which consists of 8,141 genes organized into (overlapping) gene sets. Experimental results demonstrate the eff...

  9. The advertisement call and geographic distribution of Proceratophrys dibernardoi Brandão, Caramaschi, Vaz-Silva & Campos 2013 (Anura, Odontophrynidae).

    Science.gov (United States)

    Ferreira, Cláudia Márcia Marily; Sugai, José Luiz Massao Moreira; DE Souza, Franco Leandro; DE Andrade, Sheila Pereira; Vaz-Silva, Wilian; Bastos, Rogério Pereira; DE Morais, Alessandro Ribeiro

    2016-12-09

    Proceratophrys dibernardoi Brandão, Caramaschi, Vaz-Silva & Campos 2013 has recently been described and allocated into the P. cristiceps species group, but no information about its advertisement calls has been provided (Brandão et al. 2013). Here, we describe for the first time the advertisement calls of P. dibernardoi based on specimens from Central Brazil. We also expand P. dibernardoi´s geographic distribution by reporting a new population in the State of Mato Grosso do Sul, Brazil, constituting the westernmost record for this species, and extending its known range approximately 330 km westward of the municipality of Aporé, State of Goiás (P. dibernardoi´s former westernmost record).

  10. Advertisement call and morphological variation of the poorly known and endemic Bokermannohyla juiju Faivovich, Lugli, Lourenço and Haddad, 2009 (Anura: Hylidae) from Central Bahia, Brazil.

    Science.gov (United States)

    Taucce, Pedro P G; Pinheiro, Paulo D P; Leite, Felipe S F; Garcia, Paulo C A

    2015-02-02

    Bokermannohyla juiju is a member of the B. martinsi species group and it was described based on one male specimen. In order to enhance the knowledge about the species, we describe its advertisement call and morphological variation, including for the first time data on females. We also provide additional comments about its natural history, geographic distribution, and conservation. The advertisement call of B. juiju consists of a single note, non-pulsed, harmonic structured call emitted several times in a row. Four out of five males were found calling in bromeliads. The female, as it is common in many Bokermannohyla species, presents some morphological features not shared with the males, like a non-hypertrophied forearm and less developed prepollex. 

  11. Molecular phylogeny and genetic identification of populations of two species of Feirana frogs (Amphibia: Anura, Ranidae, Dicroglossinae, Paini) endemic to China.

    Science.gov (United States)

    Wang, Bin; Jiang, Jianping; Xie, Feng; Chen, Xiaohong; Dubois, Alain; Liang, Gang; Wagner, Steven

    2009-07-01

    Using mitochondrial 12S rRNA, 16S rRNA, and ND2 sequences, we investigated phylogenetic relationships among populations of two frog species endemic to China, both referred to the genus Feirana. A sister-group relationship between the two species was supported moderately in a maximum likelihood analysis and significantly in a Bayesian analysis, but not in a maximum parsimony analysis, of combined data for the three genes. Pending resolution of this incongruence, we provisionally maintain these species in the genus Feirana. Two major clades with a deep divergence are concordant with the species F. quadranus and "F." taihangnica. In the present work, some populations from the Qinling Mountains and all those from the Funiu and the Zhongtiao-southern Taihang Mountains are referred to "F." taihangnica rather than F. quadranus, whereas others are referred to F. quadranus. Consequently, the main body of the Qinling Mountains was identified as a large contact zone between these two species. On the basis of phylogenetic relationships and the distribution pattern of populations, we propose a hypothesis for the divergence of "F." taihangnica: the ancestral species might have inhabited the westernmost Qinling Mountains and dispersed to the main Qinling Mountains, and then to the Zhongtiao-southern Taihang and Funiu Mountains. In contrast, two alternative hypotheses are suggested for F. quadranus: if the two species are confirmed as sister groups, F. quadranus might have dispersed from the westernmost Qinling to the Longmen, Qinling, Daba, and northern Wuling Mountains; alternatively, F. quadranus might have come from the northern Wuling Mountains and then dispersed to the Daba, Qinling, and Longmen mountains.

  12. Histological microstructure of the claws of the African clawed frog, Xenopus laevis (Anura: Pipidae): implications for the evolution of claws in tetrapods.

    Science.gov (United States)

    Maddin, Hillary C; Musat-Marcu, Sorin; Reisz, Robert R

    2007-05-15

    Claws are consistent components of amniote anatomy and may thus be implicated in the success of the amniote invasion of land. However, the evolutionary origin of these structures in tetrapods is unclear. Claws are present in certain extant non-amniotes, such as Xenopus laevis, the African clawed frog. The histology of the soft tissue component of the claws of X. laevis is described and compared with the amniote condition in order to gain new information on the question of homology of claws in these two groups based on patterns of keratinization. The X. laevis claw sheath is composed of a localized thickening of the corneous region of the epidermis that envelops the terminal phalanx. Noted differences between the non-cornified layers of the epidermis of the claw and non-claw region are the overall grainier appearance of the cells and an increased abundance of desmosomes in the intermediate spinosus cells. The biochemical identity of the sheath keratin(s) is inferred to be different from that of non-claw region epidermis, based on histological differences and differences in stain affinity between the two regions. The microstructure of the frog claw differs from that of amniotes in several respects, including the lack of a specified zone of growth near the base of the claw. Amphibians and amniotes, therefore, have very different patterns of claw sheath growth. Observations do not support homology of claws on a structural level in these two groups; however, further experimental work may confirm a conserved pattern of cornification in these structures in tetrapods. (c) 2006 Wiley-Liss, Inc.

  13. Generalized Group Signature Scheme

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The concept of generalized group signature scheme will bepresent. Based on the generalized secret sharing scheme proposed by Lin and Ha rn, a non-interactive approach is designed for realizing such generalized group signature scheme. Using the new scheme, the authorized subsets of the group in w hich the group member can cooperate to produce the valid signature for any messa ge can be randomly specified

  14. Multicultural group work

    DEFF Research Database (Denmark)

    Hansen, Annette Skovsted

    2014-01-01

    Motivation for the activity I use this strategy for forming groups to ensure diverse/multicultural groups that combine a variety of different strengths and resources based on student's academic, disciplinary, linguistic, national, personal and work backgrounds.......Motivation for the activity I use this strategy for forming groups to ensure diverse/multicultural groups that combine a variety of different strengths and resources based on student's academic, disciplinary, linguistic, national, personal and work backgrounds....

  15. Groups, combinatorics and geometry

    CERN Document Server

    Ivanov, A A; Saxl, J

    2003-01-01

    Over the past 20 years, the theory of groups in particular simplegroups, finite and algebraic has influenced a number of diverseareas of mathematics. Such areas include topics where groups have beentraditionally applied, such as algebraic combinatorics, finitegeometries, Galois theory and permutation groups, as well as severalmore recent developments.

  16. Asymmetry within social groups

    DEFF Research Database (Denmark)

    Barker, Jessie; Loope, Kevin J.; Reeve, H. Kern

    2016-01-01

    Social animals vary in their ability to compete with group members over shared resources and also vary in their cooperative efforts to produce these resources. Competition among groups can promote within-group cooperation, but many existing models of intergroup cooperation do not explicitly account...

  17. Higher arithmetic Chow groups

    DEFF Research Database (Denmark)

    Gil, J. I. Burgos; Feliu, Elisenda

    2012-01-01

    We give a new construction of higher arithmetic Chow groups for quasi-projective arithmetic varieties over a field. Our definition agrees with the higher arithmetic Chow groups defined by Goncharov for projective arithmetic varieties over a field. These groups are the analogue, in the Arakelov co...

  18. Work group diversity.

    Science.gov (United States)

    van Knippenberg, Daan; Schippers, Michaéla C

    2007-01-01

    Work group diversity, the degree to which there are differences between group members, may affect group process and performance positively as well as negatively. Much is still unclear about the effects of diversity, however. We review the 1997-2005 literature on work group diversity to assess the state of the art and to identify key issues for future research. This review points to the need for more complex conceptualizations of diversity, as well as to the need for more empirical attention to the processes that are assumed to underlie the effects of diversity on group process and performance and to the contingency factors of these processes.

  19. Groups of Circle Diffeomorphisms

    CERN Document Server

    Navas, Andrés

    2011-01-01

    In recent years scholars from a variety of branches of mathematics have made several significant developments in the theory of group actions. Groups of Circle Diffeomorphisms systematically explores group actions on the simplest closed manifold, the circle. As the group of circle diffeomorphisms is an important subject in modern mathematics, this book will be of interest to those doing research in group theory, dynamical systems, low dimensional geometry and topology, and foliation theory. The book is mostly self-contained and also includes numerous complementary exercises, making it an excell

  20. On -nilpotent abelian groups

    Indian Academy of Sciences (India)

    Mohammad Mehdi Nasrabadi; Ali Gholamian

    2014-11-01

    Let be a group and $A = \\text{Aut}(G)$ be the group of automorphisms of . Then, the element $[g, ] = g^{-1}(g)$ is an autocommutator of $g \\in G$ and $ \\in A$. Hence, for any natural number the -th autocommutator subgroup of is defined as $K_{m}(G)=\\langle [g,_{1},\\ldots,_{m}]|g\\in G,_{1},\\ldots,_{m}\\in A\\rangle$, where $[g, _{1}, _{2},\\ldots, _{m}] = [[g,_{1},\\ldots,_{m−1}], _{m}]$. In this paper, we introduce the new notion of -nilpotent groups and classify all abelian groups which are -nilpotent groups.

  1. CHAOTIC GROUP ACTIONS

    Institute of Scientific and Technical Information of China (English)

    ShiEnhui; ZhouLizhen; ZhouYoucheng

    2003-01-01

    It is proved that there is no chaotic group actions on any topological space with free arc.In this paper the chaotic actions of the group like G×F,where F is a finite group,are studied.In particular,under a suitable assumption ,if F is a cyclic group,then the topological space which admits a chaotic action of Z×F must admit a chatotic homeomorphism.A topological space which admits a chaotic group action but admits no chaotic horneomorphism is constructed.

  2. Grouped exposed metal heaters

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J [Bellaire, TX; Coit, William George [Bellaire, TX; Griffin, Peter Terry [Brixham, GB; Hamilton, Paul Taylor [Houston, TX; Hsu, Chia-Fu [Granada Hills, CA; Mason, Stanley Leroy [Allen, TX; Samuel, Allan James [Kular Lumpar, ML; Watkins, Ronnie Wade [Cypress, TX

    2012-07-31

    A system for treating a hydrocarbon containing formation is described. The system includes two or more groups of elongated heaters. The group includes two or more heaters placed in two or more openings in the formation. The heaters in the group are electrically coupled below the surface of the formation. The openings include at least partially uncased wellbores in a hydrocarbon layer of the formation. The groups are electrically configured such that current flow through the formation between at least two groups is inhibited. The heaters are configured to provide heat to the formation.

  3. Grouped exposed metal heaters

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Coit, William George (Bellaire, TX); Griffin, Peter Terry (Brixham, GB); Hamilton, Paul Taylor (Houston, TX); Hsu, Chia-Fu (Granada Hills, CA); Mason, Stanley Leroy (Allen, TX); Samuel, Allan James (Kular Lumpar, MY); Watkins, Ronnie Wade (Cypress, TX)

    2010-11-09

    A system for treating a hydrocarbon containing formation is described. The system includes two or more groups of elongated heaters. The group includes two or more heaters placed in two or more openings in the formation. The heaters in the group are electrically coupled below the surface of the formation. The openings include at least partially uncased wellbores in a hydrocarbon layer of the formation. The groups are electrically configured such that current flow through the formation between at least two groups is inhibited. The heaters are configured to provide heat to the formation.

  4. Group I intron ribozymes

    DEFF Research Database (Denmark)

    Nielsen, Henrik

    2012-01-01

    Group I intron ribozymes constitute one of the main classes of ribozymes and have been a particularly important model in the discovery of key concepts in RNA biology as well as in the development of new methods. Compared to other ribozyme classes, group I intron ribozymes display considerable......, the intronic products of these pathways have the potential to integrate into targets and to form various types of circular RNA molecules. Thus, group I intron ribozymes and associated elements found within group I introns is a rich source of biological phenomena. This chapter provides a strategy and protocols...... for initial characterization of new group I intron ribozymes....

  5. Group theory I essentials

    CERN Document Server

    Milewski, Emil G

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Group Theory I includes sets and mapping, groupoids and semi-groups, groups, isomorphisms and homomorphisms, cyclic groups, the Sylow theorems, and finite p-groups.

  6. Correlations of cranial morphology, ecology, and evolution in Australian suctorial tadpoles of the genera Litoria and Nyctimystes (Amphibia: Anura: Hylidae: Pelodryadinae).

    Science.gov (United States)

    Haas, A; Richards, S J

    1998-11-01

    truei differs significantly from the neobatrachian suctorial species, indicating the influence of the historically distant separation of the two taxa. A novel modification of the upper jaw abduction mechanism has evolved in L. nannotis, L. rheocola, and N. dayi. It involves an adrostral cartilage as a pushing-rod element. This mechanism and unique structural similarities of the cartilago labialis superior gives support to the preliminary assumption that the nannotis species group is more closely related to the suctorial Nyctimystes dayi than it is to other Litoria species with pond-type larvae. Suctorial larvae presumably were present in the most recent common ancestor of the Litoria nannotis group and Nyctimystes dayi.

  7. E-groups training

    CERN Multimedia

    HR Department

    2012-01-01

    There will be an e-groups training course on 16 March 2012 which will cover the main e-groups functionalities i.e.: creating and managing e-groups, difference between static and dynamic e-groups, configuring posting restrictions and archives, examples of where e-groups can be used in daily work. Even if you have already worked with e-groups, this may be a good opportunity to learn about the best practices and security related recommendations when using e-groups. You can find more details as well as enrolment form for the training (it’s free) here. The number of places is limited, so enrolling early is recommended.   Technical Training Tel. 72844

  8. Lectures on Chevalley groups

    CERN Document Server

    Steinberg, Robert

    2016-01-01

    Robert Steinberg's Lectures on Chevalley Groups were delivered and written during the author's sabbatical visit to Yale University in the 1967-1968 academic year. The work presents the status of the theory of Chevalley groups as it was in the mid-1960s. Much of this material was instrumental in many areas of mathematics, in particular in the theory of algebraic groups and in the subsequent classification of finite groups. This posthumous edition incorporates additions and corrections prepared by the author during his retirement, including a new introductory chapter. A bibliography and editorial notes have also been added. This is a great unsurpassed introduction to the subject of Chevalley groups that influenced generations of mathematicians. I would recommend it to anybody whose interests include group theory. -Efim Zelmanov, University of California, San Diego Robert Steinberg's lectures on Chevalley groups were given at Yale University in 1967. The notes for the lectures contain a wonderful exposition of ...

  9. Acute toxicity of the synthetic pyrethroid alpha-cypermethrin on the tadpoles of variable green toad, Bufotes variabilis (Amphibia:Anura

    Directory of Open Access Journals (Sweden)

    Mert Gürkan

    2016-11-01

    Full Text Available In this study, acute toxic effects of alpha-cypermethrin were investigated in the tadpoles of Bufotes variabilis (Pallas, 1769. Tadpoles at Gosner stage 19 were exposed to 0, 0.1, 5 and 10 µgl-1 of alpha-cypermethrin concentrations for 96 hours. Mortality, the changes in some morphological measurements (snout-vent length, body width, tail length, and wet weight, morphological anomalies and behavioral changes were evaluated at the end of the experiment. The 96 hours LC50 value was calculated as 15.62 µgl-1. Such morphological changes as axial anomaly, visceral edema, deformation of the mouth, and tail deformation were observed in 83% and 95% of the tadpoles in the groups treated with 5 and 10 µgl-1 of alpha-cypermethrin. Behavioral changes such as shortening of the swimming distance and immobility were recorded in all tadpoles exposed to alpha-cypermethrin. When all findings were evaluated totally, it was concluded that alpha-cypermethrin had negative effects on the development of the tadpoles of B. variabilis

  10. Systematics of treefrogs of the Hypsiboas calcaratus and Hypsiboas fasciatus species complex (Anura, Hylidae with the description of four new species

    Directory of Open Access Journals (Sweden)

    Marcel Caminer

    2014-01-01

    Full Text Available We review the systematics of the Hypsiboas calcaratus species complex, a group of widely distributed Amazonian hylid frogs. A comprehensive analysis of genetic, morphological, and bioacoustic datasets uncovered the existence of eleven candidate species, six of which are confirmed. Two of them correspond to Hypsiboas fasciatus and Hypsiboas calcaratus and the remaining four are new species that we describe here. Hypsiboas fasciatus sensu stricto has a geographic range restricted to the eastern Andean foothills of southern Ecuador while Hypsiboas calcaratus sensu stricto has a wide distribution in the Amazon basin. Hypsiboas almendarizae sp. n. occurs at elevations between 500 and 1950 m in central and northern Ecuador; the other new species (H. maculateralis sp. n., H. alfaroi sp. n., and H. tetete sp. n. occur at elevations below 500 m in Amazonian Ecuador and Peru. The new species differ from H. calcaratus and H. fasciatus in morphology, advertisement calls, and mitochondrial and nuclear DNA sequences. Five candidate species from the Guianan region, Peru, and Bolivia are left as unconfirmed. Examination of the type material of Hyla steinbachi, from Bolivia, shows that it is not conspecific with H. fasciatus and thus is removed from its synonymy.

  11. Una nueva especie de rana de cristal del género Hyalinobatrachium (Anura: Centrolenidae del Delta del Río Orinoco, Venezuela

    Directory of Open Access Journals (Sweden)

    J. Celsa Señaris

    2001-12-01

    Full Text Available Se describe una nueva especie de Hyalinobatrachium del grupo fleischmanni, H. mondolfii, de las planicies inundables del delta del río Orinoco, Venezuela. Hyalinobatrachium mondolfii se distingue del resto de las especies del grupo por la siguiente combinación de caracteres: peritoneo parietal translúcido, pericardio y peritoneos visceral y hepático blancos, coloración dorsal en vida verde claro con diminutos puntos amarillos y en preservativo crema uniforme con diminutos melanóforos oscuros (visibles solo bajo magnificación, huesos blancos en vida, palmeadura de manos y pies extensa, cabeza redondeada en vista dorsal e inclinada en vista lateral, piel dorsal granular y un canto con frecuencia fundamental superior a los 5 000 HzA new species of Hyalinobatrachium of the fleischmanni group, H. mondolfii, is described from the Orinoco delta floodplains in Venezuela. This new species can be distinguished from other congeners by the following combination of characters: parietal peritoneum clear, pericardium white, visceral and hepatic peritoneum white, color in life pale green with diminute yellow spots and, in preservative, cream with small dark melanophores (visible only under magnification, bones white in life, extense webbing, snout round in dorsal view and inclinate in lateral view, dorsal skin granulate and a advertisement call with a fundamental frequency greater than 5000 Hz

  12. Group Psychotherapy in Italy.

    Science.gov (United States)

    Giannone, Francesca; Giordano, Cecilia; Di Blasi, Maria

    2015-10-01

    This article describes the history and the prevailing orientations of group psychotherapy in Italy (psychoanalytically oriented, psychodrama, CBT groups) and particularly group analysis. Provided free of charge by the Italian health system, group psychotherapy is growing, but its expansion is patchy. The main pathways of Italian training in the different group psychotherapy orientations are also presented. Clinical-theoretical elaboration on self development, psychopathology related to group experiences, and the methodological attention paid to objectives and methods in different clinical groups are issues related to group therapy in Italy. Difficulties in the relationship between research and clinical practice are discussed, as well as the empirical research network that tries to bridge the gap between research and clinical work in group psychotherapy. The economic crisis in Italy has led to massive cuts in health care and to an increasing demand for some forms of psychological treatment. For these reasons, and because of its positive cost-benefit ratio, group psychotherapy is now considered an important tool in the national health care system to expand the clinical response to different forms of psychological distress.

  13. Morphological variation, advertisement call, and tadpoles of Bokermannohyla nanuzae (Bokermann, 1973), and taxonomic status of B. feioi (Napoli & Caramaschi, 2004) (Anura, Hylidae, Cophomantini).

    Science.gov (United States)

    Walker, Marina; Lourenço, Ana Carolina Calijorne; Pimenta, Bruno V S; Nascimento, Luciana Barreto

    2015-03-24

    Bokermannohyla nanuzae (Bokermann & Sazima 1973) and B. feioi (Napoli & Caramaschi 2004) belong to the B. cir-cumdata species group. The type locality of the former is Serra do Cipó, Espinhaço mountain range, and of the latter is Parque Estadual do Ibitipoca, Mantiqueira mountain range, both in Minas Gerais State, Brazil. Differences on dorsal draw-ing pattern of adults, oral disc morphology of tadpoles, and temporal properties of calls were proposed to distinguish these two species. However, several specimens found between the two type localities remain unidentified because diagnostic characters and states occur in all of these populations. Thus, in order to assess these characters variations, we performed an analysis of the morphology and morphometry of adults, vocalization, and morphology of tadpoles. Specimens were divided into three operational taxonomic units (OTUs): B. nanuzae (Serra do Cipó and northwards, Espinhaço mountain range), B. cf. nanuzae (Quadrilátero Ferrífero, Espinhaço mountain range, south of Serra do Cipó), and B. feioi (Serra do Ibitipoca, Mantiqueira mountain range). Drawing patterns of the dorsum and limbs show clinal variation and the three units are morphometrically very similar. Temporal and spectral properties of calls overlap in these three units. The diagnostic differences originally proposed for tadpoles are intrapopulational variations and occur in specimens from all of the locations analyzed. We found that these three units are morphologically indistinguishable. Therefore, we designate Bok-ermannohyla feioi (Napoli & Caramaschi 2004) as a junior synonym of Bokermannohyla nanuzae (Bokermann & Sazima 1973), extending its geographical distribution to the Mantiqueira mountain range.

  14. A new species of limestone karst inhabiting forest frog, genus Platymantis (Amphibia: Anura: Ceratobatrachidae: subgenus Lupacolus) from southern Luzon Island, Philippines.

    Science.gov (United States)

    Brown, Rafe M; De Layola, Louise Abigail; Lorenzo, Antonio; Diesmos, Mae Lowe L; Diesmos, Arvin C

    2015-11-25

    We describe a new species of limestone karst dwelling forest frog of the genus Platymantis from the Quezon Protected Landscape in southeastern Luzon Island, Philippines. We assign Platymantis quezoni, sp. nov., to the diverse assemblage of terrestrial species in the Platymantis dorsalis Group, subgenus Lupacolus on the basis of its body size and proportions, only slightly expanded terminal discs of the fingers and toes, and its terrestrial microhabitat. The new species is distinguished from these and all other Philippine congeners by features of its external morphology, its restriction to a distinctive limestone karst microhabitat, and its advertisement call, which is unique among frogs of the family Ceratobatrachidae. Several distinguishing morphological characters include its moderate body size (22.1-33.9 mm SVL for 16 adult males and 32.4-39.7 mm SVL for five adult females), slightly expanded terminal discs of the fingers and toes, smooth skin with limited dermal tuberculation, and a dorsal color pattern of mottled tan to dark brown with black blotches. The new species is the sixth Philippine Platymantis known to occur exclusively on limestone karst substrates (previously known karst-obligate species include: P. bayani, P. biak, P. insulatus, P. paengi, and P. speleaus). Recently accelerated discovery of limestone karst anurans across the Philippines suggests that numerous additional species may await discovery on the hundreds of scattered karst formations throughout the archipelago. This possibility suggests that a major conservation priority in coming years will be to study, characterize, describe, and preserve the endemic species supported by this patchy, unique and imperiled type of forest ecosystem in the Philippines.

  15. The first taxonomic revaluation of the Iranian water frogs of the genus Pelophylax (Anura: Ranidae) using sequences of the mitochondrial genome.

    Science.gov (United States)

    Pesarakloo, Alireza; Rastegar-Pouyani, Eskandar; Rastegar-Pouyani, Nasrollah; Kami, Hajigholi; Najibzadeh, Masoumeh; Khosravani, Azar; Oraie, Hamzeh

    2017-05-01

    The Eurasian water frog species and their geographic ranges have undergone considerable changes in the last four decades, but the Iranian populations have largely remained unknown. All the Iranian populations of water frogs, despite their vast distribution range have attributed to a single species: Rana ridibunda. In order to understand the phylogenetic relationships and taxonomic status of water frogs of Iran, we collected samples from many populations across the country and used the mitochondrial DNA sequence variation. A data set with a final sequence length of 616 nucleotides was generated for Cyt b from 70 individuals of Pelophylax in which there are 422 invariable sites, 174 variable sites of which 123 were parsimony informative. In total, 43 haplotypes were found (Hd: 0.9752). The result demonstrated that, two major clades with strong support can be identified within the Iranian water frogs. One of these clades that include north western and southwestern populations forms a monophyletic group along with P. bedriagae samples from Turkey. The second clade consists of water frog populations of north and northeastern parts of Iran which in turn is subdivided into two subclades. Inclusion of water frog samples from adjacent areas showed that the second clade of our study is, most likely, a distinct taxonomic entity at species rank with its two subclades indicating two diagnosable subspecies for the clade. In conclusion, we suggest that two distinct species, P. bedriagae and Pelophylax sp., with its two subspecies, should be identified as water frogs of Iran. In Addition, another traditionally reported water frog of Iran, P.ridibundus, most likely should be excluded from the Iranian water frog's checklist.

  16. Systematics of the Rhinella margaritifera complex (Anura, Bufonidae) from western Ecuador and Panama with insights in the biogeography of Rhinella alata

    Science.gov (United States)

    dos Santos, Sueny P.; Ibáñez, Roberto; Ron, Santiago R.

    2015-01-01

    Abstract The Rhinella margaritifera species group consists of 17 species of toads distributed in tropical and subtropical South America and eastern Central America. The identity of some of its species is poorly understood and there are numerous undescribed cryptic species. Among them, the status of Rhinella margaritifera is one of the most problematic. Its range includes lowland rainforests separated by the Andes, the Chocoan rainforest to the west and the Amazonian rainforest to the east. This distribution is puzzling because the Andes are an old and formidable barrier to gene flow and therefore should generate vicariant speciation between disjunct lowland populations. Herein we clarify the taxonomy of populations of the Rhinella margaritifera complex from Central America and the Chocó region of South America. The morphological and genetic variation of Rhinella margaritifera was examined from 39 populations from Chocó, 24 from the upper Amazon region of Ecuador, and 37 from Panama, including the holotype of the Panamanian Rhinella alata. Phylogenetic analyses were performed based on mitochondrial genes 12S rRNA, 16S rRNA, and cytochrome c oxidase I (COI) and the nuclear gene Tyrosinase (Tyr). The genetic and morphological data show that Panamanian and Chocoan populations are conspecific. In the phylogeny, populations from Chocó and Panama form a well-supported clade. The morphology of the holotype of Rhinella alata falls within the variation range of Panamanian and Chocoan populations. Based on all this evidence, we assign the populations from western Ecuador and Panama to Rhinella alata and demonstrate that the unusual distribution pattern of “Rhinella margaritifera” on both sides of the Andes was an artifact of incorrectly defined species boundaries. PMID:25987881

  17. Blood groups systems

    Directory of Open Access Journals (Sweden)

    Ranadhir Mitra

    2014-01-01

    Full Text Available International Society of Blood Transfusion has recently recognized 33 blood group systems. Apart from ABO and Rhesus system, many other types of antigens have been noticed on the red cell membranes. Blood grouping and cross-matching is one of the few important tests that the anaesthesiologist orders during perioperative period. Hence, a proper understanding of the blood group system, their clinical significance, typing and cross-matching tests, and current perspective are of paramount importance to prevent transfusion-related complications. Nonetheless, the knowledge on blood group system is necessary to approach blood group-linked diseases which are still at the stage of research. This review addresses all these aspects of the blood groups system.

  18. Stochastic Lie group integrators

    CERN Document Server

    Malham, Simon J A

    2007-01-01

    We present Lie group integrators for nonlinear stochastic differential equations with non-commutative vector fields whose solution evolves on a smooth finite dimensional manifold. Given a Lie group action that generates transport along the manifold, we pull back the stochastic flow on the manifold to the Lie group via the action, and subsequently pull back the flow to the corresponding Lie algebra via the exponential map. We construct an approximation to the stochastic flow in the Lie algebra via closed operations and then push back to the Lie group and then to the manifold, thus ensuring our approximation lies in the manifold. We call such schemes stochastic Munthe-Kaas methods after their deterministic counterparts. We also present stochastic Lie group integration schemes based on Castell--Gaines methods. These involve using an underlying ordinary differential integrator to approximate the flow generated by a truncated stochastic exponential Lie series. They become stochastic Lie group integrator schemes if...

  19. Geometric group theory

    CERN Document Server

    Bestvina, Mladen; Vogtmann, Karen

    2014-01-01

    Geometric group theory refers to the study of discrete groups using tools from topology, geometry, dynamics and analysis. The field is evolving very rapidly and the present volume provides an introduction to and overview of various topics which have played critical roles in this evolution. The book contains lecture notes from courses given at the Park City Math Institute on Geometric Group Theory. The institute consists of a set of intensive short courses offered by leaders in the field, designed to introduce students to exciting, current research in mathematics. These lectures do not duplicate standard courses available elsewhere. The courses begin at an introductory level suitable for graduate students and lead up to currently active topics of research. The articles in this volume include introductions to CAT(0) cube complexes and groups, to modern small cancellation theory, to isometry groups of general CAT(0) spaces, and a discussion of nilpotent genus in the context of mapping class groups and CAT(0) gro...

  20. Quantum isometry groups

    CERN Document Server

    Goswami, Debashish

    2016-01-01

    This book offers an up-to-date overview of the recently proposed theory of quantum isometry groups. Written by the founders, it is the first book to present the research on the “quantum isometry group”, highlighting the interaction of noncommutative geometry and quantum groups, which is a noncommutative generalization of the notion of group of isometry of a classical Riemannian manifold. The motivation for this generalization is the importance of isometry groups in both mathematics and physics. The framework consists of Alain Connes’ “noncommutative geometry” and the operator-algebraic theory of “quantum groups”. The authors prove the existence of quantum isometry group for noncommutative manifolds given by spectral triples under mild conditions and discuss a number of methods for computing them. One of the most striking and profound findings is the non-existence of non-classical quantum isometry groups for arbitrary classical connected compact manifolds and, by using this, the authors explicitl...

  1. Presentations of groups

    CERN Document Server

    Johnson, D L

    1997-01-01

    The aim of this book is to provide an introduction to combinatorial group theory. Any reader who has completed first courses in linear algebra, group theory and ring theory will find this book accessible. The emphasis is on computational techniques but rigorous proofs of all theorems are supplied. This new edition has been revised throughout, including new exercises and an additional chapter on proving that certain groups are infinite.

  2. Semisimple Metacyclic Group Algebras

    Indian Academy of Sciences (India)

    Gurmeet K Bakshi; Shalini Gupta; Inder Bir S Passi

    2011-11-01

    Given a group of order $p_1p_2$, where $p_1,p_2$ are primes, and $\\mathbb{F}_q$, a finite field of order coprime to $p_1p_2$, the object of this paper is to compute a complete set of primitive central idempotents of the semisimple group algebra $\\mathbb{F}_q[G]$. As a consequence, we obtain the structure of $\\mathbb{F}_q[G]$ and its group of automorphisms.

  3. Definably amenable NIP groups

    OpenAIRE

    Chernikov, Artem; Simon, Pierre

    2015-01-01

    We study definably amenable NIP groups. We develop a theory of generics, showing that various definitions considered previously coincide, and study invariant measures. Applications include: characterization of regular ergodic measures, a proof of the conjecture of Petrykowski connecting existence of bounded orbits with definable amenability in the NIP case, and the Ellis group conjecture of Newelski and Pillay connecting the model-theoretic connected component of an NIP group with the ideal s...

  4. Group Problem Solving

    CERN Document Server

    Laughlin, Patrick R

    2011-01-01

    Experimental research by social and cognitive psychologists has established that cooperative groups solve a wide range of problems better than individuals. Cooperative problem solving groups of scientific researchers, auditors, financial analysts, air crash investigators, and forensic art experts are increasingly important in our complex and interdependent society. This comprehensive textbook--the first of its kind in decades--presents important theories and experimental research about group problem solving. The book focuses on tasks that have demonstrably correct solutions within mathematical

  5. E-Group Arrangements

    Science.gov (United States)

    Aylesworth, Grant R.

    Group E at Uaxactún has long been considered an ancient Maya observatory in which an observer could see the sun rise along architectural alignments at the solstices and equinoxes. E-Groups named for the architectural complex list identified in Group E at Uaxactún, typically consist of a large radial pyramid on their west side and three temples on a raised platform on their east side.

  6. Explosive Technology Group

    Data.gov (United States)

    Federal Laboratory Consortium — The Explosive Technology Group (ETG) provides diverse technical expertise and an agile, integrated approach to solve complex challenges for all classes of energetic...

  7. CLASSIFICATION OF CRIMINAL GROUPS

    Directory of Open Access Journals (Sweden)

    Natalia Romanova

    2013-06-01

    Full Text Available New types of criminal groups are emerging in modern society.  These types have their special criminal subculture. The research objective is to develop new parameters of classification of modern criminal groups, create a new typology of criminal groups and identify some features of their subculture. Research methodology is based on the system approach that includes using the method of analysis of documentary sources (materials of a criminal case, method of conversations with themembers of the criminal group, method of testing the members of the criminal group and method of observation. As a result of the conducted research, we have created a new classification of criminal groups. The first type is a lawful group in its form and criminal according to its content (i.e., its target is criminal enrichment. The second type is a criminal organization which is run by so-called "white-collars" that "remain in the shadow". The third type is traditional criminal groups.  The fourth type is the criminal group, which openly demonstrates its criminal activity.

  8. Trajectory grouping structure

    Directory of Open Access Journals (Sweden)

    Maike Buchin

    2015-03-01

    Full Text Available The collective motion of a set of moving entities like people, birds, or other animals, is characterized by groups arising, merging, splitting, and ending. Given the trajectories of these entities, we define and model a structure that captures all of such changes using the Reeb graph, a concept from topology. The trajectory grouping structure has three natural parameters that allow more global views of the data in group size, group duration, and entity inter-distance. We prove complexity bounds on the maximum number of maximal groups that can be present, and give algorithms to compute the grouping structure efficiently. We also study how the trajectory grouping structure can be made robust, that is, how brief interruptions of groups can be disregarded in the global structure, adding a notion of persistence to the structure. Furthermore, we showcase the results of experiments using data generated by the NetLogo flocking model and from the Starkey project. The Starkey data describe the movement of elk, deer, and cattle. Although there is no ground truth for the grouping structure in this data, the experiments show that the trajectory grouping structure is plausible and has the desired effects when changing the essential parameters. Our research provides the first complete study of trajectory group evolvement, including combinatorial,algorithmic, and experimental results.

  9. Groups as moral anchors

    NARCIS (Netherlands)

    Ellemers, N.; van der Toorn, J

    2015-01-01

    Morality indicates what is the ‘right’ and the ‘wrong’ way to behave. However, what people see as moral can shift, depending on defining norms and distinctive features of the groups to which they belong. Acting in ways that are considered ‘moral’ by the group secures inclusion and elicits respect

  10. Study Groups in Denmark

    DEFF Research Database (Denmark)

    Hjorth, Poul G.

    2007-01-01

    Since 1998 European Study Groups have been held in Denmark, and Danish companies from LEGO and NOVO to very small high-tech firms have participated. I briefly describe the history, the organisation and the format of the Danish Study Groups, and highlight a few problem solutions....

  11. Fairness and Ability Grouping.

    Science.gov (United States)

    Strike, Kenneth A.

    1983-01-01

    A recent controversy regarding ability grouping is that it is often perceived as a means whereby racial or class bias can be subtly transformed into mechanisms of discrimination which exhibit the appearance of fairness and objectivity. This article addresses the question of fairness in ability grouping. (CJB)

  12. Group Work. Research Brief

    Science.gov (United States)

    Walker, Karen

    2010-01-01

    According to Johnson and Johnson, group work helps increase student retention and satisfaction, develops strong oral communication and social skills, as well as higher self-esteem (University of Minnesota, n.d.). Group work, when planned and implemented deliberately and thoughtfully helps students develop cognitive and leadership skills as well as…

  13. Democratic Group Work

    Science.gov (United States)

    Laursen, Erik K.; Tate, Thomas F.

    2012-01-01

    For a century, democratic values have called for abandoning coercive approaches and teaching children and youth to be responsible citizens. The authors explore strategies for creating respectful environments and positive group cultures with challenging youth. They offer suggestions to adult group facilitators to support youth in developing…

  14. Small Group Inquiry.

    Science.gov (United States)

    Koller, Martin M.

    Learning in small groups is a practical way to bring about behavior change. The inquiry learning process is perceived to be the most natural and scientific way of learning. Skills developed include those of problem-solving task analysis, decision-making, value formation and adaptability. The art of small group interaction is developed. Factual…

  15. CHINA INTERNATIONAL PUBLISHING GROUP

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The China International Publishing Group (CIPG) specializes in international communications. Its operationsencompass reporting, editing, translation, publishing, printing, distribution, and the Internet. It incorporates sevenpublishing companies, five magazines and 19 periodicals, published in over 20 languages. The ChinaInternational Book Trading Corporation, another group facet, distributes all of these to over 180 countries and

  16. Isotropy in group cohomology

    DEFF Research Database (Denmark)

    Ben David, Nir; Ginosar, Yuval; Meir, Ehud

    2014-01-01

    The analog of Lagrangians for symplectic forms over finite groups is studied, motivated by the fact that symplectic G  -forms with a normal Lagrangian N◃G  are in one-to-one correspondence, up to inflation, with bijective 1-cocycle data on the quotients G/N  . This yields a method to construct...... groups of central type from such quotients, known as Involutive Yang–Baxter groups. Another motivation for the search of normal Lagrangians comes from a non-commutative generalization of Heisenberg liftings that require normality. Although it is true that symplectic forms over finite nilpotent groups...... always admit Lagrangians, we exhibit an example where none of these subgroups is normal. However, we prove that symplectic forms over nilpotent groups always admit normal Lagrangians if all their p  -Sylow subgroups are of order less than p 8   ....

  17. Ordered groups and topology

    CERN Document Server

    Clay, Adam

    2016-01-01

    This book deals with the connections between topology and ordered groups. It begins with a self-contained introduction to orderable groups and from there explores the interactions between orderability and objects in low-dimensional topology, such as knot theory, braid groups, and 3-manifolds, as well as groups of homeomorphisms and other topological structures. The book also addresses recent applications of orderability in the studies of codimension-one foliations and Heegaard-Floer homology. The use of topological methods in proving algebraic results is another feature of the book. The book was written to serve both as a textbook for graduate students, containing many exercises, and as a reference for researchers in topology, algebra, and dynamical systems. A basic background in group theory and topology is the only prerequisite for the reader.

  18. Supervision and group dynamics

    DEFF Research Database (Denmark)

    Hansen, Søren; Jensen, Lars Peter

    2004-01-01

    as well as at Aalborg University. The first visible result has been participating supervisors telling us that the course has inspired them to try supervising group dynamics in the future. This paper will explore some aspects of supervising group dynamics as well as, how to develop the Aalborg model...... An important aspect of the problem based and project organized study at Aalborg University is the supervision of the project groups. At the basic education (first year) it is stated in the curriculum that part of the supervisors' job is to deal with group dynamics. This is due to the experience...... that many students are having difficulties with practical issues such as collaboration, communication, and project management. Most supervisors either ignore this demand, because they do not find it important or they find it frustrating, because they do not know, how to supervise group dynamics...

  19. Automorphism groups of Quandles

    CERN Document Server

    Elhamdadi, M; Restrepo, R

    2010-01-01

    We prove that the automorphism group of the dihedral quandle with n elements is isomorphic to the affine group of the integers mod n, and also obtain the inner automorphism group of this quandle. In [9], automorphism groups of quandles (up to isomorphisms) of order less than or equal to 5 were given. With the help of the software Maple, we compute the inner and automorphism groups of all seventy three quandles of order six listed in the appendix of [4]. Since computations of automorphisms of quandles relates to the problem of classification of quandles, we also describe an algorithm implemented in C for computing all quandles (up to isomorphism) of order less than or equal to nine.

  20. Perceiving persons and groups.

    Science.gov (United States)

    Hamilton, D L; Sherman, S J

    1996-04-01

    This article analyzes the similarities and differences in forming impressions of individuals and in developing conceptions of groups. In both cases, the perceiver develops a mental conception of the target (individual or group) on the basis of available information and uses that information to make judgments about that person or group. However, a review of existing evidence reveals differences in the outcomes of impressions formed of individual and group targets, even when those impressions are based on the very same behavioral information. A model is proposed to account for these differences. The model emphasizes the role of differing expectancies of unity and coherence in individual and group targets, which in turn engage different mechanisms for processing information and making judgments. Implications of the model are discussed.

  1. Impedance group summary

    Science.gov (United States)

    Blaskiewicz, M.; Dooling, J.; Dyachkov, M.; Fedotov, A.; Gluckstern, R.; Hahn, H.; Huang, H.; Kurennoy, S.; Linnecar, T.; Shaposhnikova, E.; Stupakov, G.; Toyama, T.; Wang, J. G.; Weng, W. T.; Zhang, S. Y.; Zotter, B.

    1999-12-01

    The impedance working group was charged to reply to the following 8 questions relevant to the design of high-intensity proton machines such as the SNS or the FNAL driver. These questions were first discussed one by one in the whole group, then each ne of them assigned to one member to summarize. On the lst morning these contributions were publicly read, re-discussed and re-written where required—hence they are not the opinion of a particular person, but rather the averaged opinion of all members of the working group. (AIP)

  2. Group key management

    Energy Technology Data Exchange (ETDEWEB)

    Dunigan, T.; Cao, C.

    1997-08-01

    This report describes an architecture and implementation for doing group key management over a data communications network. The architecture describes a protocol for establishing a shared encryption key among an authenticated and authorized collection of network entities. Group access requires one or more authorization certificates. The implementation includes a simple public key and certificate infrastructure. Multicast is used for some of the key management messages. An application programming interface multiplexes key management and user application messages. An implementation using the new IP security protocols is postulated. The architecture is compared with other group key management proposals, and the performance and the limitations of the implementation are described.

  3. Groups and Violence

    Science.gov (United States)

    Bhavnani, Ravi; Miodownik, Dan; Riolo, Rick

    Violence can take place along a multitude of cleavages, e.g., (1) between political groups like the Kach Movement, pitting West Bank settlers against Israeli governments supporting the land-for-peace agenda; (2) between religious groups, such as Christians and Muslims in the Nigerian cities of Jos and Kaduna; (3) along class lines, as in India between Dalits and members of the Brahminical upper castes, upwardly mobile intermediate castes, and even other backward castes such as the Thevars; and (4) between ethnic groups such as the Hutu and Tutsi, both within and across state boundaries in Rwanda and neighboring Burundi.

  4. Creativity and group innovation

    NARCIS (Netherlands)

    Nijstad, B.A.; de Dreu, C.K.W.

    2002-01-01

    Comments on M. West's article regarding the validity of an integrative model of creativity and innovation implementation in work groups. Variables affecting the level of team innovation; Relationship between predictors and team innovation; Promotion of constructive conflict.

  5. Groups – Additive Notation

    Directory of Open Access Journals (Sweden)

    Coghetto Roland

    2015-06-01

    Full Text Available We translate the articles covering group theory already available in the Mizar Mathematical Library from multiplicative into additive notation. We adapt the works of Wojciech A. Trybulec [41, 42, 43] and Artur Korniłowicz [25].

  6. Homogeneous group, research, institution

    Directory of Open Access Journals (Sweden)

    Francesca Natascia Vasta

    2014-09-01

    Full Text Available The work outlines the complex connection among empiric research, therapeutic programs and host institution. It is considered the current research state in Italy. Italian research field is analyzed and critic data are outlined: lack of results regarding both the therapeutic processes and the effectiveness of eating disorders group analytic treatment. The work investigates on an eating disorders homogeneous group, led into an eating disorder outpatient service. First we present the methodological steps the research is based on including the strong connection among theory and clinical tools. Secondly clinical tools are described and the results commented. Finally, our results suggest the necessity of validating some more specifical hypothesis: verifying the relationship between clinical improvement (sense of exclusion and painful emotions reduction and specific group therapeutic processes; verifying the relationship between depressive feelings, relapses and transition trough a more differentiated groupal field.Keywords: Homogeneous group; Eating disorders; Institutional field; Therapeutic outcome

  7. Language and Group Identity.

    Science.gov (United States)

    Milroy, Leslie

    1982-01-01

    Explores the tension between the manner in which intergroup language differences are used to symbolize group membership and the manner in which they mirror and reinforce social class and power distinctions. (EKN)

  8. Homogenous finitary symmetric groups

    Directory of Open Access Journals (Sweden)

    Otto‎. ‎H‎. Kegel

    2015-03-01

    Full Text Available We characterize strictly diagonal type of embeddings of finitary symmetric groups in terms of cardinality and the characteristic. Namely, we prove the following. Let kappa be an infinite cardinal. If G=underseti=1stackrelinftybigcupG i , where G i =FSym(kappan i , (H=underseti=1stackrelinftybigcupH i , where H i =Alt(kappan i , is a group of strictly diagonal type and xi=(p 1 ,p 2 ,ldots is an infinite sequence of primes, then G is isomorphic to the homogenous finitary symmetric group FSym(kappa(xi (H is isomorphic to the homogenous alternating group Alt(kappa(xi , where n 0 =1,n i =p 1 p 2 ldotsp i .

  9. Building Bunk Group Buddies.

    Science.gov (United States)

    Nelson, Denise Cabrero

    2000-01-01

    Describes how camp counselors can foster camaraderie among campers through participative decision making, name games, listening, adventure courses, storytelling, spending time in nature, decorating cabins, avoiding favoritism, setting rules, admitting faults, setting group goals, and praising sincere efforts. (TD)

  10. Singular Renormalization Group Equations

    OpenAIRE

    Minoru, HIRAYAMA; Department of Physics, Toyama University

    1984-01-01

    The possible behaviour of the effective charge is discussed in Oehme and Zimmermann's scheme of the renormalization group equation. The effective charge in an example considered oscillates so violently in the ultraviolet limit that the bare charge becomes indefinable.

  11. Toleration, Groups, and Multiculturalism

    DEFF Research Database (Denmark)

    Lægaard, Sune

    2014-01-01

    to the political and social relationship between the subject and the objects of toleration. Finally, toleration is often argued to be a normative requirement on the basis of the way it affects the object or receiver of toleration, e.g. on the basis of the good of or right to freedom from non-interference which......The chapter considers how groups might be relevant as objects of policies of toleration and the different senses 'group' might have in relation to questions of toleration. The chapter argues that groups can be relevant to toleration in several different ways as objects of toleration. Toleration...... is routinely defined as involving an objection component, a power requirement and an acceptance component. The objection and acceptance components refer to reasons or dispositions of the subjects of toleration, e.g. public authorities deciding how to act in relation to groups. The power condition refers...

  12. Radiation Protection Group

    CERN Multimedia

    2006-01-01

    The Radioactive Waste Section of the Radiation Protection Group wishes to inform you that the Radioactive Waste Treatment Centre will be closed on the afternoon of Tuesday 19 December 2006. Thank-you for your understanding.

  13. Parton Distributions Working Group

    Energy Technology Data Exchange (ETDEWEB)

    de Barbaro, L.; Keller, S. A.; Kuhlmann, S.; Schellman, H.; Tung, W.-K.

    2000-07-20

    This report summarizes the activities of the Parton Distributions Working Group of the QCD and Weak Boson Physics workshop held in preparation for Run II at the Fermilab Tevatron. The main focus of this working group was to investigate the different issues associated with the development of quantitative tools to estimate parton distribution functions uncertainties. In the conclusion, the authors introduce a Manifesto that describes an optimal method for reporting data.

  14. Fuzzy Soft Topological Groups

    Directory of Open Access Journals (Sweden)

    S. Nazmul

    2014-03-01

    Full Text Available Notions of Lowen type fuzzy soft topological space are introduced and some of their properties are established in the present paper. Besides this, a combined structure of a fuzzy soft topological space and a fuzzy soft group, which is termed here as fuzzy soft topological group is introduced. Homomorphic images and preimages are also examined. Finally, some definitions and results on fuzzy soft set are studied.

  15. Networks and Small Groups

    OpenAIRE

    Kadushin, Charles

    2005-01-01

    Homans' insights that interaction and sentiment are in a feedback loop that includes clique formation, social ranking and leadership are formalized and derived from a set of limited assumptions and propositions. Freeman's model of groups is used to detect pure informal groups, those that are not consequential upon anything else than sheer hanging around. It produces a system of cliques and rankings based purely on the rates of transitive triads that may include a third who is only weakly conn...

  16. Groups, rings, modules

    CERN Document Server

    Auslander, Maurice

    2014-01-01

    This classic monograph is geared toward advanced undergraduates and graduate students. The treatment presupposes some familiarity with sets, groups, rings, and vector spaces. The four-part approach begins with examinations of sets and maps, monoids and groups, categories, and rings. The second part explores unique factorization domains, general module theory, semisimple rings and modules, and Artinian rings. Part three's topics include localization and tensor products, principal ideal domains, and applications of fundamental theorem. The fourth and final part covers algebraic field extensions

  17. N-ary Groups

    CERN Document Server

    Gal'mak, Alexander M

    2011-01-01

    The book "N-ary Groups" (in Russian) consists of two Parts. It is intended on the one hand as an initial introduction to the theory of n-ary groups, and on the other hand it contains the published results by the author on this subject. At present, the theory of n-ary groups developing but slowly from group theory. Nonetheless, ternary and n-ary structures have recently been applied to modern models of elementary particle physics. One of the author's goals in this book is to draw the attention of mathematicians and theoretical physicists to the theory of n-ary groups, to some of its distinguishing features, and to details relevant to its further development and application. Part I: Theorems of Post and Gluskin-Hosszu. 1.1. Classical definitions of n-ary groups. Examples. 1.2. Analogies of identity and inverse elements. 1.3. Equivalent sequences. 1.4. Post's coset theorem. 1.5. Theorem of Gluskin-Hosszu. 1.6. Connection between the Post's coset theorem and theorem of Gluskin-Hosszu. Addition and comments. Part ...

  18. Coordinating Group report

    Energy Technology Data Exchange (ETDEWEB)

    1994-01-01

    In December 1992, western governors and four federal agencies established a Federal Advisory Committee to Develop On-site Innovative Technologies for Environmental Restoration and Waste Management (the DOIT Committee). The purpose of the Committee is to advise the federal government on ways to improve waste cleanup technology development and the cleanup of federal sites in the West. The Committee directed in January 1993 that information be collected from a wide range of potential stakeholders and that innovative technology candidate projects be identified, organized, set in motion, and evaluated to test new partnerships, regulatory approaches, and technologies which will lead to improve site cleanup. Five working groups were organized, one to develop broad project selection and evaluation criteria and four to focus on specific contaminant problems. A Coordinating Group comprised of working group spokesmen and federal and state representatives, was set up to plan and organize the routine functioning of these working groups. The working groups were charged with defining particular contaminant problems; identifying shortcomings in technology development, stakeholder involvement, regulatory review, and commercialization which impede the resolution of these problems; and identifying candidate sites or technologies which could serve as regional innovative demonstration projects to test new approaches to overcome the shortcomings. This report from the Coordinating Group to the DOIT Committee highlights the key findings and opportunities uncovered by these fact-finding working groups. It provides a basis from which recommendations from the DOIT Committee to the federal government can be made. It also includes observations from two public roundtables, one on commercialization and another on regulatory and institutional barriers impeding technology development and cleanup.

  19. Facilities removal working group

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    This working group`s first objective is to identify major economic, technical, and regulatory constraints on operator practices and decisions relevant to offshore facilities removal. Then, the group will try to make recommendations as to regulatory and policy adjustments, additional research, or process improvements and/or technological advances, that may be needed to improve the efficiency and effectiveness of the removal process. The working group will focus primarily on issues dealing with Gulf of Mexico platform abandonments. In order to make the working group sessions as productive as possible, the Facilities Removal Working Group will focus on three topics that address a majority of the concerns and/or constraints relevant to facilities removal. The three areas are: (1) Explosive Severing and its Impact on Marine Life, (2) Pile and Conductor Severing, and (3) Deep Water Abandonments This paper will outline the current state of practice in the offshore industry, identifying current regulations and specific issues encountered when addressing each of the three main topics above. The intent of the paper is to highlight potential issues for panel discussion, not to provide a detailed review of all data relevant to the topic. Before each panel discussion, key speakers will review data and information to facilitate development and discussion of the main issues of each topic. Please refer to the attached agenda for the workshop format, key speakers, presentation topics, and panel participants. The goal of the panel discussions is to identify key issues for each of the three topics above. The working group will also make recommendations on how to proceed on these key issues.

  20. The Skull of Phyllomedusa sauvagii (Anura, Hylidae).

    Science.gov (United States)

    Ruiz-Monachesi, Mario R; Lavilla, Esteban O; Montero, Ricardo

    2016-05-01

    The hylid genus Phyllomedusa comprises charismatic frogs commonly known as monkey, leaf or green frogs, and is the most diverse genus of the subfamily Phyllomedusinae, including about 31 species. Although there is some information about the anatomy of these frogs, little is known about the osteology. Here the adult skull of Phyllomedusa sauvagii, both articulated and disarticulated, is described and the intraspecific variation is reported. Additionally, cartilage associated with the adult skull, such as the nasal capsules, auditory apparatus, and hyobranchial apparatus, are included in the analysis. Further examination of disarticulated bones reveals their remarkable complexity, specifically in the sphenethmoid and of the oocipital region. The description of disarticulated bones is useful for the identification of fossil remains as well as providing morphological characteristics that are phylogenetically informative. When comparing the skull morphology with the available information of other species of the genus, Phyllomesusa sauvagii skull resembles more that of P. vaillantii and P. venusta than P. atelopoides.

  1. Osteological differentiation among Iberian Pelodytes (Anura, Pelodytidae).

    OpenAIRE

    2002-01-01

    Se analiza la diferenciación morfológica en Pelodytes mediante el análisis comparado de una muestra de elementos óseos desarticulados procedentes de las principales regiones del esqueleto macho adulto. Un conjunto de 35 rasgos interespecíficamente diferenciales, analizada bajo diversos grupos externos, permite inferir que P. ibericus y P. punctatus forman un grupo hermano frente a P. caucasicus. La especie caucásica mantiene una morfología muy primitiva, con sólo 17-23% de estados derivados, ...

  2. Melanophryniscus montevidensis (Philippi, 1902) (Anura: Bufonidae)

    OpenAIRE

    Tedros,Marcelo; Kolenc, Francisco; Borteiro, Claudio

    2001-01-01

    Brasil, Estado de Rio Grande do Sul, Alvorada, Barra do Chui, 33°45'S 53°16' W. Febrero de 1989. Colector: M. Tedros. (Colección de Batracios de la Secci ón Zoología Vertebrados de la Facultad de Ciencias de la Universidad de la República, Uruguay ZVCB 7276, ZVCB 7277 y ZVCB 7278).

  3. Melanophryniscus montevidensis (Philippi, 1902 (Anura: Bufonidae

    Directory of Open Access Journals (Sweden)

    Tedros, Marcelo

    2001-01-01

    Full Text Available Brasil, Estado de Rio Grande do Sul, Alvorada, Barra do Chui, 33°45'S 53°16' W. Febrero de 1989. Colector: M. Tedros. (Colección de Batracios de la Secci ón Zoología Vertebrados de la Facultad de Ciencias de la Universidad de la República, Uruguay ZVCB 7276, ZVCB 7277 y ZVCB 7278.

  4. Linear algebraic groups

    CERN Document Server

    Springer, T A

    1998-01-01

    "[The first] ten chapters...are an efficient, accessible, and self-contained introduction to affine algebraic groups over an algebraically closed field. The author includes exercises and the book is certainly usable by graduate students as a text or for self-study...the author [has a] student-friendly style… [The following] seven chapters... would also be a good introduction to rationality issues for algebraic groups. A number of results from the literature…appear for the first time in a text." –Mathematical Reviews (Review of the Second Edition) "This book is a completely new version of the first edition. The aim of the old book was to present the theory of linear algebraic groups over an algebraically closed field. Reading that book, many people entered the research field of linear algebraic groups. The present book has a wider scope. Its aim is to treat the theory of linear algebraic groups over arbitrary fields. Again, the author keeps the treatment of prerequisites self-contained. The material of t...

  5. Matrix groups for undergraduates

    CERN Document Server

    Tapp, Kristopher

    2016-01-01

    Matrix groups touch an enormous spectrum of the mathematical arena. This textbook brings them into the undergraduate curriculum. It makes an excellent one-semester course for students familiar with linear and abstract algebra and prepares them for a graduate course on Lie groups. Matrix Groups for Undergraduates is concrete and example-driven, with geometric motivation and rigorous proofs. The story begins and ends with the rotations of a globe. In between, the author combines rigor and intuition to describe the basic objects of Lie theory: Lie algebras, matrix exponentiation, Lie brackets, maximal tori, homogeneous spaces, and roots. This second edition includes two new chapters that allow for an easier transition to the general theory of Lie groups. From reviews of the First Edition: This book could be used as an excellent textbook for a one semester course at university and it will prepare students for a graduate course on Lie groups, Lie algebras, etc. … The book combines an intuitive style of writing w...

  6. Illinois Wind Workers Group

    Energy Technology Data Exchange (ETDEWEB)

    David G. Loomis

    2012-05-28

    The Illinois Wind Working Group (IWWG) was founded in 2006 with about 15 members. It has grown to over 200 members today representing all aspects of the wind industry across the State of Illinois. In 2008, the IWWG developed a strategic plan to give direction to the group and its activities. The strategic plan identifies ways to address critical market barriers to the further penetration of wind. The key to addressing these market barriers is public education and outreach. Since Illinois has a restructured electricity market, utilities no longer have a strong control over the addition of new capacity within the state. Instead, market acceptance depends on willing landowners to lease land and willing county officials to site wind farms. Many times these groups are uninformed about the benefits of wind energy and unfamiliar with the process. Therefore, many of the project objectives focus on conferences, forum, databases and research that will allow these stakeholders to make well-educated decisions.

  7. Transitive conformal holonomy groups

    CERN Document Server

    Alt, Jesse

    2011-01-01

    For $(M,[g])$ a conformal manifold of signature $(p,q)$ and dimension at least three, the conformal holonomy group $\\mathrm{Hol}(M,[g]) \\subset O(p+1,q+1)$ is an invariant induced by the canonical Cartan geometry of $(M,[g])$. We give a description of all possible connected conformal holonomy groups which act transitively on the M\\"obius sphere $S^{p,q}$, the homogeneous model space for conformal structures of signature $(p,q)$. The main part of this description is a list of all such groups which also act irreducibly on $\\R^{p+1,q+1}$. For the rest, we show that they must be compact and act decomposably on $\\R^{p+1,q+1}$, in particular, by known facts about conformal holonomy the conformal class $[g]$ must contain a metric which is locally isometric to a so-called special Einstein product.

  8. Quantum threshold group signature

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In most situations, the signer is generally a single person. However, when the message is written on behalf of an organization, a valid message may require the approval or consent of several persons. Threshold signature is a solution to this problem. Generally speaking, as an authority which can be trusted by all members does not exist, a threshold signature scheme without a trusted party appears more attractive. Following some ideas of the classical Shamir’s threshold signature scheme, a quantum threshold group signature one is proposed. In the proposed scheme, only t or more of n persons in the group can generate the group signature and any t-1 or fewer ones cannot do that. In the verification phase, any t or more of n signature receivers can verify the message and any t-1 or fewer receivers cannot verify the validity of the signature.

  9. Focus group discussions

    CERN Document Server

    Hennink, Monique M

    2014-01-01

    The Understanding Research series focuses on the process of writing up social research. The series is broken down into three categories: Understanding Statistics, Understanding Measurement, and Understanding Qualitative Research. The books provide researchers with guides to understanding, writing, and evaluating social research. Each volume demonstrates how research should be represented, including how to write up the methodology as well as the research findings. Each volume also reviews how to appropriately evaluate published research. Focus Group Discussions addresses the challenges associated with conducting and writing focus group research. It provides detailed guidance on the practical and theoretical considerations in conducting focus group discussions including: designing the discussion guide, recruiting participants, training a field team, moderating techniques and ethical considerations. Monique Hennink describes how a methodology section is read and evaluated by others, such as journal reviewers or ...

  10. Hierarchies in student groups

    OpenAIRE

    Güntert, Manuel

    2008-01-01

    This is a research about hierarchies in student groups. It shows how they are built und what sense they have. The position of a student in his student peer group is evaluated. The influence of the look, the style, the behaviour of the other sex, the gender, the origin, the prehistory, the appearance, achievement and their effect on hierarchies is analysed and the impact of charisma and organisation are compared. The meaning of this research is to indicate how a student must be to get the lead...

  11. Fourier Analysis on Groups

    CERN Document Server

    Rudin, Walter

    2011-01-01

    In the late 1950s, many of the more refined aspects of Fourier analysis were transferred from their original settings (the unit circle, the integers, the real line) to arbitrary locally compact abelian (LCA) groups. Rudin's book, published in 1962, was the first to give a systematic account of these developments and has come to be regarded as a classic in the field. The basic facts concerning Fourier analysis and the structure of LCA groups are proved in the opening chapters, in order to make the treatment relatively self-contained.

  12. Upgraded Coal Interest Group

    Energy Technology Data Exchange (ETDEWEB)

    Evan Hughes

    2009-01-08

    The Upgraded Coal Interest Group (UCIG) is an EPRI 'users group' that focuses on clean, low-cost options for coal-based power generation. The UCIG covers topics that involve (1) pre-combustion processes, (2) co-firing systems and fuels, and (3) reburn using coal-derived or biomass-derived fuels. The UCIG mission is to preserve and expand the economic use of coal for energy. By reducing the fuel costs and environmental impacts of coal-fired power generation, existing units become more cost effective and thus new units utilizing advanced combustion technologies are more likely to be coal-fired.

  13. Group theory and chemistry

    CERN Document Server

    Bishop, David M

    1993-01-01

    Group theoretical principles are an integral part of modern chemistry. Not only do they help account for a wide variety of chemical phenomena, they simplify quantum chemical calculations. Indeed, knowledge of their application to chemical problems is essential for students of chemistry. This complete, self-contained study, written for advanced undergraduate-level and graduate-level chemistry students, clearly and concisely introduces the subject of group theory and demonstrates its application to chemical problems.To assist chemistry students with the mathematics involved, Professor Bishop ha

  14. GroupFinder

    DEFF Research Database (Denmark)

    Bøgh, Kenneth Sejdenfaden; Skovsgaard, Anders; Jensen, Christian S.

    2013-01-01

    of PoIs relevant to a user's intent has became a problem of automated spatio-textual information retrieval. Over the last several years, substantial research has gone into the invention of functionality and efficient implementations for retrieving nearby PoIs. However, with a couple of exceptions....... Such groups are relevant to users who wish to conveniently explore several options before making a decision such as to purchase a specific product. Specifically, we demonstrate a practical proposal for finding top-k PoI groups in response to a query. We show how problem parameter settings can be mapped...

  15. Homomorphisms between Kaehler groups

    CERN Document Server

    Arapura, Donu

    2009-01-01

    This is partly a survey and partly a research article. Some known results and open problems about Kaehler groups (fundamental groups of compact Kaehler manifolds) are discussed. A new notion of Kaehler homomorphism is introduced. This is a homomorphism induced by a holomorphic map between these types of manifolds. Some obstructions for a homomorphism to be Kaehler are discussed. Among these is the main result on the vanishing of a certain cohomology class associated to such map. This is reduced to the decomposition theorem for perverse sheaves suitably extended to Kaehler orbifolds.

  16. Group Based Interference Alignment

    CERN Document Server

    Ma, Yanjun; Chen, Rui; Yao, Junliang

    2010-01-01

    in $K$-user single-input single-output (SISO) frequency selective fading interference channels, it is shown that the achievable multiplexing gain is almost surely $K/2$ by using interference alignment (IA). However when the signaling dimensions is limited, allocating all the resource to all the users simultaneously is not optimal. According to this problem, a group based interference alignment (GIA) scheme is proposed and a search algorithm is designed to get the group patterns and the resource allocation among them. Analysis results show that our proposed scheme achieves a higher multiplexing gain when the resource is limited.

  17. The Multiplication Group of an AG-group

    OpenAIRE

    Shah, Muhammad; Ali, Asif; Ahmad, Imtiaz; Sorge, Volker

    2014-01-01

    We investigate the multiplication group of a special class of quasigroup called AG-group. We prove some interesting results such as: the multiplication group of an AG-group of order n is non-abelian group of order 2n and its left section is an abelian group of order n. The inner mapping group of an AG-group of any order is a cyclic group of order 2.

  18. Lacunarity for compact groups.

    Science.gov (United States)

    Edwards, R E; Hewitt, E; Ross, K A

    1971-01-01

    Let G be a compact Abelian group with character group X. A subset Delta of X is called a [unk](q) set (1 < q < infinity) if for all trigonometric polynomials f = [unk](k=1) (n) alpha(k)chi(k) (chi(1),...,chi(n) [unk] Delta) an inequality parallelf parallel(q) [unk] [unk] parallelf parallel(1) obtains, where [unk] is a positive constant depending only on Delta. The subset Delta is called a Sidon set if every bounded function on Delta can be matched by a Fourier-Stieltjes transform. It is known that every Sidon set is a [unk](q) set for all q. For G = T, X = Z, Rudin (J. Math. Mech., 9, 203 (1960)) has found a set that is [unk](q) for all q but not Sidon. We extend this result to all infinite compact Abelian groups G: the character group X contains a subset Delta that is [unk](q) for all q, 1 < q < infinity, but Delta is not a Sidon set.

  19. FAW Group Gorporation

    Institute of Scientific and Technical Information of China (English)

    Yan Feng

    2007-01-01

    @@ As the founder of China's automobile industry, FAW Group Corporation (FAW) has maintained a dominant position in the automotive industry since its founding in 1953 in terms of its total assets, Production capacity, domestic and international sales, market share, and brand recognition.

  20. Working Group Report: Neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    de Gouvea, A.; Pitts, K.; Scholberg, K.; Zeller, G. P. [et al.

    2013-10-16

    This document represents the response of the Intensity Frontier Neutrino Working Group to the Snowmass charge. We summarize the current status of neutrino physics and identify many exciting future opportunities for studying the properties of neutrinos and for addressing important physics and astrophysics questions with neutrinos.

  1. Parton Distributions Working Group

    CERN Document Server

    de Barbaro, Lucy; Brock, R.; Casey, D.; Demina, R.; Giele, W.T.; Hirosky, R.; Huston, J.; Kalk, J.; Keller, S.A.; Klasen, M.; Kosower, D.A.; Kramer, M.; Kretzer, S.; Kuhlmann, S.; Martin, R.; Olness, Fredrick I.; Plehn, T.; Pumplin, J.; Scalise, R.J.; Schellman, H.; Smith, J.; Soper, D.E.; Sterman, George F.; Stump, D.; Tung, W.K.; Varelas, N.; Vogelsang, W.; Yang, Un-Ki

    2000-01-01

    The main focus of this working group was to investigate the different issues associated with the development of quantitative tools to estimate parton distribution functions uncertainties. In the conclusion, we introduce a "Manifesto" that describes an optimal method for reporting data.

  2. An Intergenerational Women's Group.

    Science.gov (United States)

    Fogler, Janet

    1989-01-01

    Discusses the Intergenerational Women's Group, formed to provide social support and an interchange of ideas between women of different generations. Provides a model for such a program that may be offered in geriatric medical clinics. Discusses the impact of intergenerational support for both the old and the young. (Author/BHK)

  3. Group B Streptococcus

    Directory of Open Access Journals (Sweden)

    Albert H. Adriaanse

    1995-01-01

    Full Text Available Objective: Group B streptococcus (GBS, Streptococcus agalactiae is an important cause of neonatal sepsis. Prevention is possible by intrapartum screening for maternal GBS carriership and antimicrobial treatment of colonized women with risk factors during labor. The conflicting results of diagnostic performance are reported both for the newly developed rapid GBS antigen tests and Gram's stain.

  4. Unclonable Group Identification

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Dupont, Kasper; Pedersen, Michael Østergaard

    2006-01-01

    We introduce and motivate the concept of unclonable group identification, that provides maximal protection against sharing of identities while still protecting the anonymity of users. We prove that the notion can be realized from any one-way function and suggest a more efficient implementation...

  5. Anaphylaxis vulnerable groups

    African Journals Online (AJOL)

    Ehab

    Professor of Pediatric Allergy and Immunology, Ain Shams University, Cairo, Egypt. Age groups ... fever, emotional stress, travel or other disruption of routine ... Anaphylaxis following immunization is a rare event ... estimated.15,16 An estimate of 1 per 100 000 after. MMR ... pregnancy include low back pain, uterine cramps,.

  6. GROUPS IN PEPTIDE SYNTHESIS

    African Journals Online (AJOL)

    asparagine amino acid residues and other amino acids having amide groups at ... Amines were reacted with Boc-Asp-on-OBzl in the presence of DCC to give .... systems chloroform-ethyl acetate (321 iv/v) (A) and chloroform-methanol-glacial acetic ... three 12 mL portions of 5% aqueous sodium bicarbonate, and five 15 mL ...

  7. Grouping Illumination Frameworks

    Science.gov (United States)

    Zdravkovic, Suncica; Economou, Elias; Gilchrist, Alan

    2012-01-01

    According to Koffka (1935), the lightness of a target surface is determined by the relationship between the target and the illumination frame of reference to which it belongs. However, each scene contains numerous illumination frames, and judging each one separately would lead to an enormous amount of computing. Grouping those frames that are in…

  8. Convolution Operators on Groups

    CERN Document Server

    Derighetti, Antoine

    2011-01-01

    This volume is devoted to a systematic study of the Banach algebra of the convolution operators of a locally compact group. Inspired by classical Fourier analysis we consider operators on Lp spaces, arriving at a description of these operators and Lp versions of the theorems of Wiener and Kaplansky-Helson.

  9. With the Radiobiology Group

    CERN Multimedia

    1980-01-01

    The Radiobiology Group carries out experiments to study the effect of radiation on living cells. The photo shows the apparatus for growing broad beans which have been irradiated by 250 GeV protons. The roots are immersed in a tank of running water (CERN Weekly Bulletin 26 January 1981 and Annual Report 1980 p. 160). Karen Panman, Marilena Streit-Bianchi, Roger Paris.

  10. Leukosis/Sarcoma Group

    Science.gov (United States)

    The leukosis/sarcoma (L/S) group of diseases designates a variety of transmissible benign and malignant neoplasms of chickens caused by members that belong to the family Retroviridae. Because the expansion of the literature on this disease, it is no longer feasible to cite all relevant publications ...

  11. Group theory in physics

    CERN Document Server

    Cornwell, J F

    1989-01-01

    Recent devopments, particularly in high-energy physics, have projected group theory and symmetry consideration into a central position in theoretical physics. These developments have taken physicists increasingly deeper into the fascinating world of pure mathematics. This work presents important mathematical developments of the last fifteen years in a form that is easy to comprehend and appreciate.

  12. Dimensions of Group Interaction

    Science.gov (United States)

    Dawidowicz, Paula

    2008-01-01

    The correlation between positive and negative group interactions and one or another of individuals' attitudes or characteristics--moral development, critical thinking, resilience, and self efficacy--has been examined previously. However, no systemic examination of individuals' development of patterns of these characteristics and those patterns'…

  13. Abandoning wells working group

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The primary objective of this working group is to identify major technical, regulatory, and environmental issues that are relevant to the abandonment of offshore wellbores. Once the issues have been identified, the working group also has the objective of making recommendations or providing potential solutions for consideration. Areas for process improvement will be identified and {open_quotes}best practices{close_quotes} will be discussed and compared to {open_quotes}minimum standards.{close_quotes} The working group will primarily focus on wellbore abandonment in the Gulf of Mexico. However, workshop participants are encouraged to discuss international issues which may be relevant to wellbore abandonment practices in the Gulf of Mexico. The Abandoning Wells Group has identified several major areas for discussion that have concerns related to both operators and service companies performing wellbore abandonments in the Gulf of Mexico. The following broad topics were selected for the agenda: (1) MMS minimum requirements and state regulations. (2) Co-existence of best practices, new technology, and P & A economics. (3) Liability and environmental issues relating to wellbore abandonment.

  14. Oviduct modifications in foam-nesting frogs, with emphasis on the genus Leptodactylus (Amphibia, Leptodactylidae)

    Science.gov (United States)

    Furness, Andrew I.; McDiarmid, Roy W.; Heyer, W. Ronald; Zug, George R.

    2010-01-01

    Various species of frogs produce foam nests that hold their eggs during development. We examined the external morphology and histology of structures associated with foam nest production in frogs of the genus Leptodactylus and a few other taxa. We found that the posterior convolutions of the oviducts in all mature female foam-nesting frogs that we examined were enlarged and compressed into globular structures. This organ-like portion of the oviduct has been called a "foam gland" and these structures almost certainly produce the secretion that is beaten by rhythmic limb movements into foam that forms the nest. However, the label "foam gland" is a misnomer because the structures are simply enlarged and tightly folded regions of the pars convoluta of the oviduct, rather than a separate structure; we suggest the name pars convoluta dilata (PCD) for this feature. Although all the foam-nesters we examined had a pars convoluta dilata, its size and shape showed considerable interspecific variation. Some of this variation likely reflects differences in the breeding behaviors among species and in the size, type, and placement of their foam nests. Other variation, particularly in size, may be associated with the physiological periodicity and reproductive state of the female, her age, and/or the number of times she has laid eggs.

  15. Lueheia inscripta (Westrumb, 1821 (Acanthocephala: Plagiorhynchidae in anurans (Leptodactylidae: Bufonidae from Mexico

    Directory of Open Access Journals (Sweden)

    Salgado-Maldonado G.

    2010-06-01

    Full Text Available Juveniles of Lueheia inscripta (Westrumb, 1821 Travassos, 1919 (Acanthocephala: Plagiorhynchidae, an acanthocephalan with six lemnisci, are reported and described from mesenteries of frogs Leptodactylus fragilis Brochi, 1877 and a toad Bufo marinus (Linnaeus, 1758 from Morelos state, Mexico. These are new host records extending the known geographical distribution of this species from Brazil and Puerto Rico to Mexico.

  16. Temporal selectivity by single neurons in the torus semicircularis of Batrachyla antartandica (Amphibia: Leptodactylidae).

    Science.gov (United States)

    Penna, M; Lin, W Y; Feng, A S

    2001-12-01

    We investigated the response selectivities of single auditory neurons in the torus semicircularis of Batrachyla antartandica (a leptodactylid from southern Chile) to synthetic stimuli having diverse temporal structures. The advertisement call for this species is characterized by a long sequence of brief sound pulses having a dominant frequency of about 2000 Hz. We constructed five different series of synthetic stimuli in which the following acoustic parameters were systematically modified, one at a time: pulse rate, pulse duration, pulse rise time, pulse fall time, and train duration. The carrier frequency of these stimuli was fixed at the characteristic frequency of the units under study (n=44). Response patterns of TS units to these synthetic call variants revealed different degrees of selectivity for each of the temporal variables. A substantial number of neurons showed preference for pulse rates below 2 pulses s(-1), approximating the values found in natural advertisement calls. Tonic neurons generally showed preferences for long pulse durations, long rise and fall times, and long train durations. In contrast, phasic and phasic-burst neurons preferred stimuli with short duration, short rise and fall times and short train durations.

  17. Plasma retinoids concentration in Leptodactylus chaquensis (Amphibia: Leptodactylidae) from rice agroecosystems, Santa Fe province, Argentina.

    Science.gov (United States)

    Teglia, Carla M; Attademo, Andrés M; Peltzer, Paola M; Goicoechea, Héctor C; Lajmanovich, Rafael C

    2015-09-01

    Retinoids are known to regulate important processes such as differentiation, development, and embryogenesis of vertebrates: Alteration in endogenous retinoids concentration is linked with teratogenic effects. Retinol (ROH), retinoid acid (RA), and isoform 13-Cis-retinoic acid (13-Cis-RA), in plasma of a native adults frog, Leptodactylus chaquensis from a rice field (RF) and a forest (reference site; RS) were measured. ROH did not vary between treatment sites. RA and 13-Cis-RA activities were higher (93.7±8.6 μg mL(-1) and 131.7±11.4 μg mL(-1), respectively) in individuals collected from RF than in those from RS (65.5±8.6 μg mL(-1) and 92.2±10.2 μg mL(-1), respectively). The ratios retinoic acid-retinol (RA/ROH) and 13-Cis-RA/ROH revealed significantly higher values in RF than in RS. RA and 13-Cis-RA concentrations in plasma on wild amphibian's species such as L. chaquensis would be suitable biomarkers of pesticide exposure in field monitoring. Finally, the mechanism of alteration in retinoid metabolites alteration should be further explored both in larvae and adult, considering that the potential exposition and uptake contaminants vary between the double lives of these vertebrates. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Communication from ST Group

    CERN Multimedia

    TS Department

    2008-01-01

    Please note that owing the preparations for the Open Days, the FM Group will not able to handle specific requests for waste collection from 2nd to 6th of April, nor removal or PC transport requests between the 31 March and 11 April. We kindly ask you to plan the collection of all types of waste and any urgent transport of office furniture or PCs before 31 March. Waste collection requests must be made by contacting FM Support on 77777 or at the e-mail address mailto:Fm.Support@cern.ch; removal of office furniture or PC transport requests must be made using the EDH ‘Transport request’ form (select "Removals" or "PC transport" from the drop-down menu). For any question concerning the sorting of waste, please consult the following web site: http://dechets-waste.web.cern.ch/dechets-waste/ Thank you for your understanding and collaboration. TS/FM Group

  19. Group and representation theory

    CERN Document Server

    Vergados, J D

    2017-01-01

    This volume goes beyond the understanding of symmetries and exploits them in the study of the behavior of both classical and quantum physical systems. Thus it is important to study the symmetries described by continuous (Lie) groups of transformations. We then discuss how we get operators that form a Lie algebra. Of particular interest to physics is the representation of the elements of the algebra and the group in terms of matrices and, in particular, the irreducible representations. These representations can be identified with physical observables. This leads to the study of the classical Lie algebras, associated with unitary, unimodular, orthogonal and symplectic transformations. We also discuss some special algebras in some detail. The discussion proceeds along the lines of the Cartan-Weyl theory via the root vectors and root diagrams and, in particular, the Dynkin representation of the roots. Thus the representations are expressed in terms of weights, which are generated by the application of the elemen...

  20. Mindfulness for group facilitation

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine; Krohn, Simon

    2014-01-01

    In this paper, we argue that mindfulness techniques can be used for enhancing the outcome of group performance. The word mindfulness has different connotations in the academic literature. Broadly speaking there is ‘mindfulness without meditation’ or ‘Western’ mindfulness which involves active...... thinking and ‘Eastern’ mindfulness which refers to an open, accepting state of mind, as intended with Buddhist-inspired techniques such as meditation. In this paper, we are interested in the latter type of mindfulness and demonstrate how Eastern mindfulness techniques can be used as a tool for facilitation....... A brief introduction to the physiology and philosophy of Eastern mindfulness constitutes the basis for the arguments of the effect of mindfulness techniques. The use of mindfulness techniques for group facilitation is novel as it changes the focus from individuals’ mindfulness practice...

  1. Gravitation Gauge Group

    CERN Document Server

    Ter-Kazarian, G T

    1997-01-01

    Suggested theory involves a drastic revision of a role of local internal symmetries in physical concept of curved geometry. Under the reflection of fields and their dynamics from Minkowski to Riemannian space a standard gauge principle of local internal symmetries is generalized. The gravitation gauge group is proposed, which is generated by hidden local internal symmetries. The developed mechanism enables one to infer Einstein's equation of gravitation, but only with strong difference from Einstein's theory at the vital point of well-defined energy-momentum tensor of gravitational field and conservation laws. The gravitational interaction as well as general distortion of manifold G(2.2.3) with hidden group U(1) was considered.

  2. Group Leaders Optimization Algorithm

    CERN Document Server

    Daskin, Anmer

    2010-01-01

    Complexity of global optimization algorithms makes implementation of the algorithms difficult and leads the algorithms to require more computer resources for the optimization process. The ability to explore the whole solution space without increasing the complexity of algorithms has a great importance to not only get reliable results but so also make the implementation of these algorithms more convenient for higher dimensional and complex-real world problems in science and engineering. In this paper, we present a new global optimization algorithm in which the influence of the leaders in social groups is used as an inspiration for the evolutionary technique that is designed into a group architecture similar to the architecture of Cooperative Coevolutionary Algorithms. Therefore, we present the implementation method and the experimental results for the single and multidimensional optimization test problems and a scientific real world problem, the energies and the geometric structures of Lennard-Jones clusters.

  3. Group Formation in Economics

    Science.gov (United States)

    Demange, Gabrielle; Wooders, Myrna

    2005-01-01

    Broad and diverse ranges of activities are conducted within and by organized groups of individuals, including political, economic and social activities. These activities have recently become a subject of intense interest in economics and game theory. Some of the topics investigated in this collection are models of networks of power and privilege, trade networks, co-authorship networks, buyer-seller networks with differentiated products, and networks of medical innovation and the adaptation of new information. Other topics are social norms on punctuality, clubs and the provision of club goods and public goods, research and development and collusive alliances among corporations, and international alliances and trading agreements. While relatively recent, the literature on game theoretic studies of group formation in economics is already vast. This volume provides an introduction to this important literature on game-theoretic treatments of situations with networks, clubs, and coalitions, including some applications.

  4. The Ombudperson Initiative Group

    CERN Document Server

    Laura Stewart

    Following many discussions that took place at some of the ATLAS Women's Network lunch gatherings, a few ATLAS women joined forces with similarly concerned CERN staff women to form a small group last Fall to discuss the need for a CERN-wide Ombudsperson. This has since evolved into the Ombudsperson Initiative Group (OIG) currently composed of the following members: Barbro Asman, Stockholm University; Pierre Charrue, CERN AB; Anna Cook, CERN IT; Catherine Delamare, CERN and IT Ombudsperson; Paula Eerola, Lund University; Pauline Gagnon, Indiana University; Eugenia Hatziangeli, CERN AB; Doreen Klem, CERN IT; Bertrand Nicquevert, CERN TS and Laura Stewart, CERN AT. On June 12, members of the OIG met with representatives of Human Resources (HR) and the Equal Opportunity Advisory Panel (EOAP) to discuss the proposal drafted by the OIG. The meeting was very positive. Everybody agreed that the current procedures at CERN applicable in the event of conflict required a thorough review, and that a professionnally trai...

  5. Multibunch working group

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The goal of this working group was to foment discussions about the use and limitations of multi-bunch, representatives from most operating or in-project synchrotron radiation sources (ALS, SPEAR, BESSY-2, SPRING-8, ANKA, DELTA, PEP-2, DIAMOND, ESRF...) have presented their experience. The discussions have been led around 3 topics: 1) resistive wall instabilities and ion instabilities, 2) higher harmonic cavities, and 3) multibunch feedback systems.

  6. Formal groups and applications

    CERN Document Server

    Hazewinkel, Michiel

    2012-01-01

    This book is a comprehensive treatment of the theory of formal groups and its numerous applications in several areas of mathematics. The seven chapters of the book present basics and main results of the theory, as well as very important applications in algebraic topology, number theory, and algebraic geometry. Each chapter ends with several pages of historical and bibliographic summary. One prerequisite for reading the book is an introductory graduate algebra course, including certain familiarity with category theory.

  7. Summaries of group discussions

    Science.gov (United States)

    Jensen, L. D.

    1972-01-01

    Group discussions following the presentations of reports on the remote sensing of Chesapeake Bay resources are presented. The parameters to be investigated by the remote sensors and the specifications of the sensors are described. Specific sensors for obtaining data on various aspects of the ecology are identified. Recommendations for establishing a data bank and additional efforts to obtain increased understanding of the ecology are submitted.

  8. Group Size and Conformity

    OpenAIRE

    Bond, Rod

    2005-01-01

    Abstract This paper reviews theory and research on the relationship between group size and conformity and presents a meta-analysis of 125 Asch-type conformity studies. It questions the assumption of a single function made in formal models of social influence and proposes instead that the function will vary depending on which social influence process predominates. It is argued that normative influence is lik...

  9. Combinatorial group theory

    CERN Document Server

    Lyndon, Roger C

    2001-01-01

    From the reviews: "This book (...) defines the boundaries of the subject now called combinatorial group theory. (...)it is a considerable achievement to have concentrated a survey of the subject into 339 pages. This includes a substantial and useful bibliography; (over 1100 ÄitemsÜ). ...the book is a valuable and welcome addition to the literature, containing many results not previously available in a book. It will undoubtedly become a standard reference." Mathematical Reviews, AMS, 1979.

  10. Group Variables and Gaming Success.

    Science.gov (United States)

    Norris, Dwight R.; Niebuhr, Robert E.

    1980-01-01

    Describes a study designed to determine the effects of group cohesiveness on group performance in a management game and, to examine the effects voluntary v assigned group membership has on the cohesiveness of the group. (Author/LLS)

  11. STEAM GENERATOR GROUP PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Clark, R. A.; Lewis, M

    1985-09-01

    This report is a summary of progress in the Surry Steam Generator Group Project for 1984. Information is presented on the analysis of two baseline eddy current inspections of the generator. Round robin series of tests using standard in-service inspection techniques are described along with some preliminary results. Observations are reported of degradation found on tubing specimens removed from the generator, and on support plates characterized in-situ. Residual stresses measured on a tubing specimen are reported. Two steam generator repair demonstrations are described; one for antivibration bar replacement, and one on tube repair methods. Chemical analyses are shown for sludge samples removed from above the tube sheet.

  12. Groups and symmetry

    CERN Document Server

    Farmer, David W

    1995-01-01

    In most mathematics textbooks, the most exciting part of mathematics-the process of invention and discovery-is completely hidden from the reader. The aim of Groups and Symmetry is to change all that. By means of a series of carefully selected tasks, this book leads readers to discover some real mathematics. There are no formulas to memorize; no procedures to follow. The book is a guide: Its job is to start you in the right direction and to bring you back if you stray too far. Discovery is left to you. Suitable for a one-semester course at the beginning undergraduate level, there are no prerequ

  13. Grouping Notes Through Nodes

    DEFF Research Database (Denmark)

    Dove, Graham; Abildgaard, Sille Julie Jøhnk; Biskjær, Michael Mose

    The Post-ItTM note is a frequently used, and yet seldom studied, design material. We investigate the functions Post-ItTM notes serve when providing cognitive support for creative design team practice. Our investigation considers the ways in which Post-ItTM notes function as design externalisations......, both individually and when grouped, and their role in categorisation in semantic long-term memory. To do this, we adopt a multimodal analytical approach focusing on interaction between humans, and between humans and artefacts, alongside language. We discuss in detail examples of four different...

  14. Social group utility maximization

    CERN Document Server

    Gong, Xiaowen; Yang, Lei; Zhang, Junshan

    2014-01-01

    This SpringerBrief explains how to leverage mobile users' social relationships to improve the interactions of mobile devices in mobile networks. It develops a social group utility maximization (SGUM) framework that captures diverse social ties of mobile users and diverse physical coupling of mobile devices. Key topics include random access control, power control, spectrum access, and location privacy.This brief also investigates SGUM-based power control game and random access control game, for which it establishes the socially-aware Nash equilibrium (SNE). It then examines the critical SGUM-b

  15. Statistical Group Comparison

    CERN Document Server

    Liao, Tim Futing

    2011-01-01

    An incomparably useful examination of statistical methods for comparisonThe nature of doing science, be it natural or social, inevitably calls for comparison. Statistical methods are at the heart of such comparison, for they not only help us gain understanding of the world around us but often define how our research is to be carried out. The need to compare between groups is best exemplified by experiments, which have clearly defined statistical methods. However, true experiments are not always possible. What complicates the matter more is a great deal of diversity in factors that are not inde

  16. Notes on quantum groups

    Energy Technology Data Exchange (ETDEWEB)

    Pressley, A.; Chari, V. (King' s Coll., London (UK). Dept. of Mathematics Tata Inst. of Fundamental Research, Bombay (India). School of Mathematics)

    1990-12-01

    The authors presents an introduction to quantum groups defined as a deformation of the universal enveloping algebra of a Lie algebra. After the description of Hopf algebras with some examples the approach of Drinfel'd and Jimbo is described, where the quantization of a Lie algebra represents a Hopf algebra, defined over the algebra of formal power series in an indetermined h. The authors show that this approach arises from a r-matrix, which satisfies the classical Yang-Baxter equation. As example quantum sl{sub 2} is considered. Furthermore the approaches of Manin and Woroniwicz and the R-matrix approach are described. (HSI).

  17. Applications of Quantum Groups

    Science.gov (United States)

    Chryssomalakos, Chryssomalis

    The main theme of this thesis is the search for applications of Quantum Group and Hopf algebraic concepts and techniques in Physics. We investigate in particular the possibilities that exist in deforming, in a self consistent way, the symmetry structure of physical theories with the hope that the resulting scheme will be of relevance in the description of physical reality. Our choice of topics reflects this motivation: we discuss deformations of rotations and Lorentz boosts, search for integrals on the quantum plane and attempt to Fourier transform functions of non -commuting coordinates. Along the way, more formal considerations prompt us to revisit integration on finite dimensional Hopf algebras, explore the interconnections between various descriptions of the quantum double and derive the algebraic structure of the quantum plane from that of the underlying deformed symmetry group. The material is structured as follows. Chapter 1 introduces the language, basic concepts and notation employed throughout this thesis. Chapter 2 focuses on Hopf algebras viewed as universal envelopes of deformed Lie algebras and their duals. Bicovariant generators enter the discussion as analogues of the classical Lie algebra generators and some of their properties are given. We comment on the geometrical interpretation of the algebraic formulation and introduce computational tools. In chapter 3 we take a close look at the quantum Lorentz Hopf algebra. The basics of complex quantum groups are presented and applied in the derivation of the algebra of the quantum Lorentz generators and its Hopf and involutive structures. We point also to isomorphisms with previous related constructions. The subject of quantum integration is explored in chapter 4. We derive a formula for the integral on a finite dimensional Hopf algebra and show its equivalence to the formulation in terms of the trace of the square of the antipode. Integration on the quantum plane is also examined and a Fourier transform

  18. Finite Symplectic Matrix Groups

    OpenAIRE

    2011-01-01

    The finite subgroups of GL(m, Q) are those subgroups that fix a full lattice in Q^m together with some positive definite symmetric form. A subgroup of GL(m, Q) is called symplectic, if it fixes a nondegenerate skewsymmetric form. Such groups only exist if m is even. A symplectic subgroup of GL(2n, Q) is called maximal finite symplectic if it is not properly contained in some finite symplectic subgroup of GL(2n, Q). This thesis classifies all conjugacy classes of maximal finite symplectic subg...

  19. Finite groups with transitive semipermutability

    Institute of Scientific and Technical Information of China (English)

    Lifang WANG; Yanming WANG

    2008-01-01

    A group G is said to be a T-group (resp. PT-group, PST-group), if normality (resp. permutability, S-permutability) is a transitive relation. In this paper, we get the characterization of finite solvable PST-groups. We also give a new characterization of finite solvable PT-groups.

  20. Communication from ST Group

    CERN Multimedia

    TS Department

    2008-01-01

    In order to prepare the organization of the Open Days, please note that FM Group will not able to take into account either specific requests for waste collection from 2nd to 6th of April, either removal or PC transport requests between the 31st and the 11th of March. We kindly ask you to plan the collection of any type of waste and the urgent transport of office furniture or PC before the 31st of March. Waste collection requests shall be formulated contacting FM Support at 77777 or at the email address mailto:Fm.Support@cern.ch; removal of office furniture or PC transport requests must be made using the EDH ‘Transport request’ form selecting the "Removals" or the "PC transport" category from the drop-down menu. For any question concerning the waste sorting, please consult the following web address: http://dechets-waste.web.cern.ch/dechets-waste/. Thank you for your understanding and collaboration. TS/FM Group

  1. AO Group Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Olivier, S

    2005-10-04

    The Adaptive Optics (AO) Group in I Division develops and tests a broad range of advanced wavefront control technologies. Current applications focus on: Remote sensing, High power lasers, Astronomy, and Human vision. In the area of remote sensing, the AO Group leads a collaborative effort with LLNL's Nonproliferation, Arms Control & International Security (NAI) Directorate on Enhanced Surveillance Imaging. The ability to detect and identify individual people or vehicles from long-range is an important requirement for proliferation detection and homeland security. High-resolution imaging along horizontal paths through the atmosphere is limited by turbulence, which blurs and distorts the image. For ranges over {approx}one km, visible image resolution can be reduced by over an order of magnitude. We have developed an approach based on speckle imaging that can correct the turbulence-induced blurring and provide high resolution imagery. The system records a series of short exposure images which freeze the atmospheric effects. We can then estimate the image magnitude and phase using a bispectral estimation algorithm which cancels the atmospheric effects while maintaining object information at the diffraction limit of the imaging system.

  2. Communication from ST Group

    CERN Multimedia

    TS Department

    2008-01-01

    In order to prepare the organization of the Open Days, please note that FM Group will not able to take into account either specific requests for waste collection from 2nd to 6th of April, either removal or PC transport requests between the 31st and the 11th of March. We kindly ask you to plan the collection of any type of waste and the urgent transport of office furniture or PC before the 31st of March. Waste collection requests shall be formulated contacting FM Support at 77777 or at the email address mailto:Fm.Support@cern.ch; removal of office furniture or PC transport requests must be made using the EDH ‘Transport request’ form selecting the "Removals" or the "PC transport" category from the drop-down menu. For any question concerning the waste sorting, please consult the following web address: http://dechets-waste.web.cern.ch/dechets-waste/. Thank you for your understanding and collaboration. TS/FM Group

  3. Gravitation gauge group

    Energy Technology Data Exchange (ETDEWEB)

    Ter-Kazarian, G. T. [Byurakan Astrophysical Observatory (Armenia)

    1997-06-01

    The suggested theory involves a drastic revision of the role of local internal symmetries in the physical concept of curved geometry. Under the reflection of fields and their dynamics from Minkowski to Riemannian space a standard gauge principle of local internal symmetries has been generalized. A gravitation gauge group is proposed, which is generated by hidden local internal symmetries. In all circumstances, it seemed to be of the greatest importance for the understanding of the physical nature of gravity. The most promising aspect in their approach so far is the fact that the energy-momentum conservation laws of gravitational interacting fields are formulated quite naturally by exploiting all the advantages of auxiliary shadow fields on flat shadow space. The mechanism developed here enables one to infer Einstein`s equation of gravitation, but only with a strong difference from Einstein`s theory at the vital point of well-defined energy-momentum tensor of gravitational field and conservation laws. The gravitational interaction as well as the general distortion of the manifold G(2.2.3) with hidden group U{sup loc} (1) has been considered.

  4. Social group and mobbing

    Directory of Open Access Journals (Sweden)

    Baltezarević Vesna

    2009-01-01

    Full Text Available Our reality, having been subject to the numerous social crises during the last decades of the 20th century, is characterized by frequent incidences of powerlessness and alienation. The man is more frequently a subject to loneliness and overcomes the feeling of worthlessness, no matter whether he considers himself an individual or a part of a whole larger social. Such an environment leads to development of aggression in all fields of ones life. This paper has as an objective the pointing out of the mental harassment that is manifested in the working environment. There is a prevalence of mobbing cases, as a mode of pathological communication. The result of this is that a person, subjected to this kind of abuse, is soon faced with social isolation. This research also aspires to initiate the need for social groups self-organization of which victims are part of. The reaction modality of a social group directly conditions the outcome of the deliberate social drama, one is subjected to it as a result of mobbing.

  5. Group Life Insurance

    CERN Multimedia

    2013-01-01

    The CERN Administration would like to remind you that staff members and fellows have the possibility to take out a life insurance contract on favourable terms through a Group Life Insurance.   This insurance is provided by the company Helvetia and is available to you on a voluntary basis. The premium, which varies depending on the age and gender of the person insured, is calculated on the basis of the amount of the death benefit chosen by the staff member/fellow and can be purchased in slices of 10,000 CHF.    The contract normally ends at the retirement age (65/67 years) or when the staff member/fellow leaves the Organization. The premium is deducted monthly from the payroll.   Upon retirement, the staff member can opt to maintain his membership under certain conditions.   More information about Group Life Insurance can be found at: Regulations (in French) Table of premiums The Pension Fund Benefit Service &...

  6. ATLAS Detector Interface Group

    CERN Multimedia

    Mapelli, L

    Originally organised as a sub-system in the DAQ/EF-1 Prototype Project, the Detector Interface Group (DIG) was an information exchange channel between the Detector systems and the Data Acquisition to provide critical detector information for prototype design and detector integration. After the reorganisation of the Trigger/DAQ Project and of Technical Coordination, the necessity to provide an adequate context for integration of detectors with the Trigger and DAQ lead to organisation of the DIG as one of the activities of Technical Coordination. Such an organisation emphasises the ATLAS wide coordination of the Trigger and DAQ exploitation aspects, which go beyond the domain of the Trigger/DAQ project itself. As part of Technical Coordination, the DIG provides the natural environment for the common work of Trigger/DAQ and detector experts. A DIG forum for a wide discussion of all the detector and Trigger/DAQ integration issues. A more restricted DIG group for the practical organisation and implementation o...

  7. Outer automorphism groups of certain 1-relator groups

    Institute of Scientific and Technical Information of China (English)

    KIM; Goansu

    2010-01-01

    Grossman first showed that outer automorphism groups of 1-relator groups given by orientable surface groups are residually finite,whence mapping class groups of orientable surfaces are residually finite.Allenby,Kim and Tang showed that outer automorphism groups of cyclically pinched 1-relator groups are residually finite,whence mapping class groups of orientable and non-orientable surfaces are residually finite.In this paper we show that outer automorphism groups of certain conjugacy separable 1-relator groups are residually finite.

  8. Are balanced groups better? : Belbin roles in collaborative learning groups

    NARCIS (Netherlands)

    Meslec, M.N.; Curseu, P.L.

    2015-01-01

    In a sample of 459 students organized in 84 groups this study tests the impact of group role balance on teamwork quality and three performance indicators in collaborative learning groups (group cognitive complexity, perceived performance and objective performance). The results show that group role

  9. Emotional collectives : How groups shape emotions and emotions shape groups

    NARCIS (Netherlands)

    van Kleef, G.A.; Fischer, A.H.

    2016-01-01

    Group settings are epicentres of emotional activity. Yet, the role of emotions in groups is poorly understood. How do group-level phenomena shape group members’ emotional experience and expression? How are emotional expressions recognised, interpreted and shared in group settings? And how do such ex

  10. Group life insurance

    CERN Multimedia

    2013-01-01

    The CERN Administration wishes to inform staff members and fellows having taken out optional life insurance under the group contract signed by CERN that the following changes to the rules and regulations entered into force on 1 January 2013:   The maximum age for an active member has been extended from 65 to 67 years. The beneficiary clause now allows insured persons to designate one or more persons of their choice to be their beneficiary(-ies), either at the time of taking out the insurance or at a later date, in which case the membership/modification form must be updated accordingly. Beneficiaries must be clearly identified (name, first name, date of birth, address).   The membership/modification form is available on the FP website: http://fp.web.cern.ch/helvetia-life-insurance For further information, please contact: Valentina Clavel (Tel. 73904) Peggy Pithioud (Tel. 72736)

  11. Grouping Synonyms by Definitions

    CERN Document Server

    Falk, Ingrid; Jacquey, Evelyne; Venant, Fabienne

    2009-01-01

    We present a method for grouping the synonyms of a lemma according to its dictionary senses. The senses are defined by a large machine readable dictionary for French, the TLFi (Tr\\'esor de la langue fran\\c{c}aise informatis\\'e) and the synonyms are given by 5 synonym dictionaries (also for French). To evaluate the proposed method, we manually constructed a gold standard where for each (word, definition) pair and given the set of synonyms defined for that word by the 5 synonym dictionaries, 4 lexicographers specified the set of synonyms they judge adequate. While inter-annotator agreement ranges on that task from 67% to at best 88% depending on the annotator pair and on the synonym dictionary being considered, the automatic procedure we propose scores a precision of 67% and a recall of 71%. The proposed method is compared with related work namely, word sense disambiguation, synonym lexicon acquisition and WordNet construction.

  12. Renormalization Group Therapy

    CERN Document Server

    Tomboulis, E T

    2007-01-01

    We point out a general problem with the procedures commonly used to obtain improved actions from MCRG decimated configurations. Straightforward measurement of the couplings from the decimated configurations, by one of the known methods, can result into actions that do not correctly reproduce the physics on the undecimated lattice. This is because the decimated configurations are generally not representative of the equilibrium configurations of the assumed form of the effective action at the measured couplings. Curing this involves fine-tuning of the chosen MCRG decimation procedure, which is also dependent on the form assumed for the effective action. We illustrate this in decimation studies of the SU(2) LGT using Swendsen and Double Smeared Blocking decimation procedures. A single-plaquette improved action involving five group representations and free of this pathology is given.

  13. NOSS science working group

    Science.gov (United States)

    The members of the NOSS Science Working Group are John Apel, Pacific Marine Environmental Laboratories/NOAA; Tim Barnett, Scripps Institution of Oceanography; Francis Bretherton (chairman), National Center for Atmospheric Research; Otis Brown, University of Miami; Joost Businger, University of Washington; Garrett Campbell, NCAR; Mark Cane, Massachusetts Institute of Technology; Robert Edwards, National Marine Fisheries Service/NOAA; James Mueller, Naval Postgraduate School; Peter Niiler, Oregon State University; James J. O'Brien, Florida State University; Norman Phillips, National Meteorological Center/NOAA; Owen Phillips, The Johns Hopkins University; Stephen Piacsek, NSTL Station, NORDA; Trevor Platt, Bedford Institute of Oceanography; Stephen Pond, University of British Columbia; Stanley Ruttenberg (executive secretary), NCAR; William Schmitz, Woods Hole Oceanographic Institution; Jerry Schubel, State University of New York; Robert Stewart, Scripps; Norbert Untersteiner, NOAA; and Alan Weinstein, Naval Environmental Prediction Research Facility.

  14. Graphs, groups and surfaces

    CERN Document Server

    White, AT

    1985-01-01

    The field of topological graph theory has expanded greatly in the ten years since the first edition of this book appeared. The original nine chapters of this classic work have therefore been revised and updated. Six new chapters have been added, dealing with: voltage graphs, non-orientable imbeddings, block designs associated with graph imbeddings, hypergraph imbeddings, map automorphism groups and change ringing.Thirty-two new problems have been added to this new edition, so that there are now 181 in all; 22 of these have been designated as ``difficult'''' and 9 as ``unsolved''''. Three of the four unsolved problems from the first edition have been solved in the ten years between editions; they are now marked as ``difficult''''.

  15. Gutzwiller renormalization group

    Science.gov (United States)

    Lanatà, Nicola; Yao, Yong-Xin; Deng, Xiaoyu; Wang, Cai-Zhuang; Ho, Kai-Ming; Kotliar, Gabriel

    2016-01-01

    We develop a variational scheme called the "Gutzwiller renormalization group" (GRG), which enables us to calculate the ground state of Anderson impurity models (AIM) with arbitrary numerical precision. Our method exploits the low-entanglement property of the ground state of local Hamiltonians in combination with the framework of the Gutzwiller wave function and indicates that the ground state of the AIM has a very simple structure, which can be represented very accurately in terms of a surprisingly small number of variational parameters. We perform benchmark calculations of the single-band AIM that validate our theory and suggest that the GRG might enable us to study complex systems beyond the reach of the other methods presently available and pave the way to interesting generalizations, e.g., to nonequilibrium transport in nanostructures.

  16. Renormalization Group Tutorial

    Science.gov (United States)

    Bell, Thomas L.

    2004-01-01

    Complex physical systems sometimes have statistical behavior characterized by power- law dependence on the parameters of the system and spatial variability with no particular characteristic scale as the parameters approach critical values. The renormalization group (RG) approach was developed in the fields of statistical mechanics and quantum field theory to derive quantitative predictions of such behavior in cases where conventional methods of analysis fail. Techniques based on these ideas have since been extended to treat problems in many different fields, and in particular, the behavior of turbulent fluids. This lecture will describe a relatively simple but nontrivial example of the RG approach applied to the diffusion of photons out of a stellar medium when the photons have wavelengths near that of an emission line of atoms in the medium.

  17. Working Group Report: Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Artuso, M.; et al.,

    2013-10-18

    Sensors play a key role in detecting both charged particles and photons for all three frontiers in Particle Physics. The signals from an individual sensor that can be used include ionization deposited, phonons created, or light emitted from excitations of the material. The individual sensors are then typically arrayed for detection of individual particles or groups of particles. Mounting of new, ever higher performance experiments, often depend on advances in sensors in a range of performance characteristics. These performance metrics can include position resolution for passing particles, time resolution on particles impacting the sensor, and overall rate capabilities. In addition the feasible detector area and cost frequently provides a limit to what can be built and therefore is often another area where improvements are important. Finally, radiation tolerance is becoming a requirement in a broad array of devices. We present a status report on a broad category of sensors, including challenges for the future and work in progress to solve those challenges.

  18. New species of Haematoloechus (Digenea: Plagiorchidae in the lung of the foothill yellow-legged frog Rana boylii (Anura, from Humboldt County, California, USA Especie nueva de Haematoloechus (Digenea: Plagiorchidae del pulmón de la rana de patas amarillas Rana boylii (Anura, de Humboldt County, California, Estados Unidos de América

    Directory of Open Access Journals (Sweden)

    David Zamparo

    2011-06-01

    Full Text Available A new species of Haematoloechus is described from the lungs of Rana boylii from Humboldt County, California. The new species is similar to Haematoloechus buttensis, Haematoloechus kernensis, and Haematoloechus complexus in general course of the uterus and gonad shape. It is similar to H. buttensis by having a cirrus sac terminating midway between the posterior margin of the pharynx and the anterior margin of the ovary, and having a smaller oral/ventral sucker ratio; to H. complexus by having the genital pore ventral to the pharynx, and it is similar to H. kernensis by having a larger oral sucker to pharynx width ratio. The new species is unique by lacking an extra-cecal longitudinal uterine loop from the hind-body. Molecularly, the new species differs 1.04-1.15% in partial 28S sequence with respect to H. complexus, and a monophyletic grouping of these specimens in a phylogenetic analysis of all available sequence data consistent with the species-specific status proposed herein. Evidence is also presented to suggest that specimens identified as H. buttensis in Rana pretiosa from British Columbia, Canada represents a new, but still undescribed species. The importance of conducting biological inventories of helminths, along with continued monitoring of populations, and collections based taxonomy are related.Una especie nueva de Haematoloechus es descrita de los pulmones de Rana boylii de Humboldt County, California. La especie nueva guarda semejanza con Haematoloechus buttensis, Haematoloechus kernensis, y Haematoloechus complexus en la disposición general del útero y en la forma de las gónadas. Es similar a H. buttensis en que la bolsa del cirro finaliza entre el margen posterior de la faringe y el margen anterior del ovario, y en presentar una relación menor entre la ventosa oral y el acetábulo; a H. complexus por tener el poro genital ventral a la faringe, y a H. kernensis por tener una relación mayor del ancho de la ventosa oral contra la

  19. Representation Theory of Algebraic Groups and Quantum Groups

    CERN Document Server

    Gyoja, A; Shinoda, K-I; Shoji, T; Tanisaki, Toshiyuki

    2010-01-01

    Invited articles by top notch expertsFocus is on topics in representation theory of algebraic groups and quantum groupsOf interest to graduate students and researchers in representation theory, group theory, algebraic geometry, quantum theory and math physics

  20. Relationship between the genetic structure of the Andean toad Rhinella spinulosa (Anura: Bufonidae and the northern Chile landscape (21°- 24° S Relación entre la estructura genética del sapo andino Rhinella spinulosa (Anura: Bufonidae y el paisaje del norte de Chile (21°- 24° S

    Directory of Open Access Journals (Sweden)

    CAROLINA E GALLARDO

    2011-09-01

    Full Text Available We analyzed the relationship of landscape and environmental features on the genetic differentiation of Rhinella spinulosa (Wiegmann, 1834 in the Altiplano of Antofagasta (Chile. We performed three types of analyses at different spatial scales: (1 Considering all populations; (2 Grouping populations by watershed and by sub-watershed; and (3 Using the results of a spatial analysis of molecular variation (SAMOVA. Landscape features were incorporated using Geographic Information Systems, with three hypothetical dispersal models: (1 Euclidean distance (null model; (2 Least cost based on wetland locations; and (3 Least cost based on least slopes. We also included differences in temperature, precipitation and altitude among localities. The Akaike information criterion was used to select the best model and the relative importance of each variable in the model was estimated with partial regressions. We found a high genetic differentiation among populations (Fst = 0.693 and isolation by distance (r = 0.767. AMOVA showed that the watersheds explained 8.67 % of the genetic variance and sub-watersheds 35.99 %. At the largest spatial scale, considering all populations, the model that best explained genetic differentiation included Euclidean distance, altitude and annual precipitation. At a smaller scale, in two of three sub-watersheds (Río San Pedro and Salar de Atacama the genetic differentiation was best explained by landscape variables (principally temperature and altitude. At the smallest scale, considering those populations that have diverged recently detected by SAMOVA, the genetic differentiation was best explained by the wetland-based route and annual precipitation. This approach revealed the importance of landscape features in the colonization of R. spinulosa in this zone.Se evaluó la relación entre las características del paisaje y ambientales y la diferenciación genética de Rhinella spinulosa en el altiplano de la Región de Antofagasta

  1. Development of new group members' in-group and out-group stereotypes: changes in perceived group variability and ethnocentrism.

    Science.gov (United States)

    Ryan, C S; Bogart, L M

    1997-10-01

    Changes in new members' in-group and out-group stereotypes were examined, distinguishing among three stereotype components: stereotypicality, dispersion, and ethnocentrism. Pledges in 4 sororities judged their in-group and out-groups 4 times during their 8-month induction. Overall, out-groups were judged more stereotypically than in-groups at every wave. Although out-groups were initially perceived as more dispersed than in-groups, decreased out-group dispersion resulted in a shift toward out-group homogeneity. Ethnocentrism was present at every wave but decreased because of decreased in-group positivity. The authors discuss implications of these results for existing explanations of stereotype development. It is suggested that other aspects of group socialization (R.L. Moreland & J.M. Levine, 1982) are needed to explain fully the development of intergroup perceptions for new group members.

  2. Cluster functional renormalization group

    Science.gov (United States)

    Reuther, Johannes; Thomale, Ronny

    2014-01-01

    Functional renormalization group (FRG) has become a diverse and powerful tool to derive effective low-energy scattering vertices of interacting many-body systems. Starting from a free expansion point of the action, the flow of the RG parameter Λ allows us to trace the evolution of the effective one- and two-particle vertices towards low energies by taking into account the vertex corrections between all parquet channels in an unbiased fashion. In this work, we generalize the expansion point at which the diagrammatic resummation procedure is initiated from a free UV limit to a cluster product state. We formulate a cluster FRG scheme where the noninteracting building blocks (i.e., decoupled spin clusters) are treated exactly, and the intercluster couplings are addressed via RG. As a benchmark study, we apply our cluster FRG scheme to the spin-1/2 bilayer Heisenberg model (BHM) on a square lattice where the neighboring sites in the two layers form the individual two-site clusters. Comparing with existing numerical evidence for the BHM, we obtain reasonable findings for the spin susceptibility, the spin-triplet excitation energy, and quasiparticle weight even in coupling regimes close to antiferromagnetic order. The concept of cluster FRG promises applications to a large class of interacting electron systems.

  3. The analytic renormalization group

    Science.gov (United States)

    Ferrari, Frank

    2016-08-01

    Finite temperature Euclidean two-point functions in quantum mechanics or quantum field theory are characterized by a discrete set of Fourier coefficients Gk, k ∈ Z, associated with the Matsubara frequencies νk = 2 πk / β. We show that analyticity implies that the coefficients Gk must satisfy an infinite number of model-independent linear equations that we write down explicitly. In particular, we construct "Analytic Renormalization Group" linear maps Aμ which, for any choice of cut-off μ, allow to express the low energy Fourier coefficients for |νk | < μ (with the possible exception of the zero mode G0), together with the real-time correlators and spectral functions, in terms of the high energy Fourier coefficients for |νk | ≥ μ. Operating a simple numerical algorithm, we show that the exact universal linear constraints on Gk can be used to systematically improve any random approximate data set obtained, for example, from Monte-Carlo simulations. Our results are illustrated on several explicit examples.

  4. Group Milieu in systemic and psychodynamic group therapy

    DEFF Research Database (Denmark)

    Lau, Marianne Engelbrecht

    in a randomized study of systemic versus psychodynamic group therapy, that the short-term outcome for patients who received systemic group psychotherapy was significantly better than the outcome for patients who received psychodynamic group psychotherapy. The current study assessed the group milieu in both groups....... Methods: This randomized prospective study included 106 women: 52 assigned to psychodynamic group psychotherapy and 54 assigned to systemic group psychotherapy. The Group Environment Scale (GES) was filled in the mid phase of therapy and analysed in three dimensions and 10 subscales. Results: The systemic...... group was characterized by statistically significant highest scores on Relationship (ES = 1.27) and System Maintenance / Change Dimension (ES= 1.28), while the scores for Personal Growth Dimension were comparable in the two groups. Group S had statistically significant higher scores on the following...

  5. Introduction to complex reflection groups and their braid groups

    CERN Document Server

    Broué, Michel

    2010-01-01

    Weyl groups are particular cases of complex reflection groups, i.e. finite subgroups of GLr(C) generated by (pseudo)reflections. These are groups whose polynomial ring of invariants is a polynomial algebra. It has recently been discovered that complex reflection groups play a key role in the theory of finite reductive groups, giving rise as they do to braid groups and generalized Hecke algebras which govern the representation theory of finite reductive groups. It is now also broadly agreed upon that many of the known properties of Weyl groups can be generalized to complex reflection groups. The purpose of this work is to present a fairly extensive treatment of many basic properties of complex reflection groups (characterization, Steinberg theorem, Gutkin-Opdam matrices, Solomon theorem and applications, etc.) including the basic findings of Springer theory on eigenspaces. In doing so, we also introduce basic definitions and properties of the associated braid groups, as well as a quick introduction to Bessis' ...

  6. The Automorphism Groups of the Groups of Order 32p

    CERN Document Server

    Becker, Elaine W

    2009-01-01

    The results of computer computations determining the automorphism groups of the groups of order 32$p$ for $p \\geq 3$ are given in several tables. Presentations for the automorphism groups of the groups of order 32, which in many cases appear as direct product factors in the automorphism groups of order $32p$, are also presented for completeness. Many of the groups of order 32$p$ with a normal sylow $p$-subgroup have automorphism groups of the form: Hol($C_p$)$ \\times $Invariant Factor. A suggestion is made as to how one might determine this invariant factor using only information on the automorphism group of the 2-group associated with the group of order 32$p$, and the normal subgroup of the 2-group associated with the extension of the group of order $32p$. Some general comments on the groups of order $32p^2$ and their automorphism groups are made. A few explicit calculations for the groups of order $32p^2$ are reported here. Knowing the automorphism groups for the groups of order $32p$ enables us to explicit...

  7. Fermilab Steering Group Report

    Energy Technology Data Exchange (ETDEWEB)

    Steering Group, Fermilab; /Fermilab

    2007-12-01

    The Fermilab Steering Group has developed a plan to keep U.S. accelerator-based particle physics on the pathway to discovery, both at the Terascale with the LHC and the ILC and in the domain of neutrinos and precision physics with a high-intensity accelerator. The plan puts discovering Terascale physics with the LHC and the ILC as Fermilab's highest priority. While supporting ILC development, the plan creates opportunities for exciting science at the intensity frontier. If the ILC remains near the Global Design Effort's technically driven timeline, Fermilab would continue neutrino science with the NOvA experiment, using the NuMI (Neutrinos at the Main Injector) proton plan, scheduled to begin operating in 2011. If ILC construction must wait somewhat longer, Fermilab's plan proposes SNuMI, an upgrade of NuMI to create a more powerful neutrino beam. If the ILC start is postponed significantly, a central feature of the proposed Fermilab plan calls for building an intense proton facility, Project X, consisting of a linear accelerator with the currently planned characteristics of the ILC combined with Fermilab's existing Recycler Ring and the Main Injector accelerator. The major component of Project X is the linac. Cryomodules, radio-frequency distribution, cryogenics and instrumentation for the linac are the same as or similar to those used in the ILC at a scale of about one percent of a full ILC linac. Project X's intense proton beams would open a path to discovery in neutrino science and in precision physics with charged leptons and quarks. World-leading experiments would allow physicists to address key questions of the Quantum Universe: How did the universe come to be? Are there undiscovered principles of nature: new symmetries, new physical laws? Do all the particles and forces become one? What happened to the antimatter? Building Project X's ILC-like linac would offer substantial support for ILC development by accelerating the

  8. Fermilab Steering Group Report

    Energy Technology Data Exchange (ETDEWEB)

    Beier, Eugene; /Pennsylvania U.; Butler, Joel; /Fermilab; Dawson, Sally; /Brookhaven; Edwards, Helen; /Fermilab; Himel, Thomas; /SLAC; Holmes, Stephen; /Fermilab; Kim, Young-Kee; /Fermilab /Chicago U.; Lankford, Andrew; /UC, Irvine; McGinnis, David; /Fermilab; Nagaitsev, Sergei; /Fermilab; Raubenheimer, Tor; /SLAC /Fermilab

    2007-01-01

    The Fermilab Steering Group has developed a plan to keep U.S. accelerator-based particle physics on the pathway to discovery, both at the Terascale with the LHC and the ILC and in the domain of neutrinos and precision physics with a high-intensity accelerator. The plan puts discovering Terascale physics with the LHC and the ILC as Fermilab's highest priority. While supporting ILC development, the plan creates opportunities for exciting science at the intensity frontier. If the ILC remains near the Global Design Effort's technically driven timeline, Fermilab would continue neutrino science with the NOVA experiment, using the NuMI (Neutrinos at the Main Injector) proton plan, scheduled to begin operating in 2011. If ILC construction must wait somewhat longer, Fermilab's plan proposes SNuMI, an upgrade of NuMI to create a more powerful neutrino beam. If the ILC start is postponed significantly, a central feature of the proposed Fermilab plan calls for building an intense proton facility, Project X, consisting of a linear accelerator with the currently planned characteristics of the ILC combined with Fermilab's existing Recycler Ring and the Main Injector accelerator. The major component of Project X is the linac. Cryomodules, radio-frequency distribution, cryogenics and instrumentation for the linac are the same as or similar to those used in the ILC at a scale of about one percent of a full ILC linac. Project X's intense proton beams would open a path to discovery in neutrino science and in precision physics with charged leptons and quarks. World-leading experiments would allow physicists to address key questions of the Quantum Universe: How did the universe come to be? Are there undiscovered principles of nature: new symmetries, new physical laws? Do all the particles and forces become one? What happened to the antimatter? Building Project X's ILC-like linac would offer substantial support for ILC development by accelerating the

  9. Group B Streptococcus and Pregnancy

    Science.gov (United States)

    ... B Strep and Pregnancy • What is group B streptococcus (GBS)? • What does it mean to be colonized ... planned cesarean birth? •Glossary What is group B streptococcus (GBS)? Group B streptococcus is one of the ...

  10. Harmonic Analysis and Group Representation

    CERN Document Server

    Figa-Talamanca, Alessandro

    2011-01-01

    This title includes: Lectures - A. Auslander, R. Tolimeri - Nilpotent groups and abelian varieties, M Cowling - Unitary and uniformly bounded representations of some simple Lie groups, M. Duflo - Construction de representations unitaires d'un groupe de Lie, R. Howe - On a notion of rank for unitary representations of the classical groups, V.S. Varadarajan - Eigenfunction expansions of semisimple Lie groups, and R. Zimmer - Ergodic theory, group representations and rigidity; and, Seminars - A. Koranyi - Some applications of Gelfand pairs in classical analysis.

  11. Post-Disaster Social Justice Group Work and Group Supervision

    Science.gov (United States)

    Bemak, Fred; Chung, Rita Chi-Ying

    2011-01-01

    This article discusses post-disaster group counseling and group supervision using a social justice orientation for working with post-disaster survivors from underserved populations. The Disaster Cross-Cultural Counseling model is a culturally responsive group counseling model that infuses social justice into post-disaster group counseling and…

  12. Group Leader Development: Effects of Personal Growth and Psychoeducational Groups

    Science.gov (United States)

    Ohrt, Jonathan H.; Robinson, E. H., III; Hagedorn, W. Bryce

    2013-01-01

    The purpose of this quasi-experimental study was to compare the effects of personal growth groups and psychoeducational groups on counselor education students' (n = 74) empathy and group leader self-efficacy. Additionally, we compared the degree to which participants in each group valued: (a) cohesion, (b) catharsis, and (c) insight. There were no…

  13. A Comparison of Workplace Groups with Groups in Education.

    Science.gov (United States)

    Jacobs, George M.; James, Joyce E.

    The use of groups in both the workplace and schools has been increasing. In the workplace, groups reflective of a growing trend toward worker participation in management have been variously referred to as self-managing work teams, self-directed work groups, quality circles, autonomous work groups, and cross-functional teams. Schools have used many…

  14. On the Central Automorphism Groups of Finite p-Groups

    Institute of Scientific and Technical Information of China (English)

    Ali-Reza Jamali; Hamid Mousavi

    2002-01-01

    Using the concept of isoclinism, we study closely the center of the group Autc(G) of central automorphisms for a certain class of finite p-groups G.We also give some necessary and sufficient conditions on a finite purely non-abelian p-group G of class 2 (p odd) for the group Autc(G) to be elementary abelian.

  15. Interagency Advanced Power Group -- Steering group meeting minutes

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-18

    This document contains the draft meeting minutes of the Steering Group of the Interagency Advanced Power Group. Included are the discussions resulting from the presentation of working group reports and the results of a discussion of IAPG policies and procedures. In the appendix are the reports of the following working groups: Electrical, Mechanical, Solar, and Systems.

  16. Abstract Lie groups and locally compact topological groups

    Directory of Open Access Journals (Sweden)

    Jacek Lech

    2004-05-01

    Full Text Available We introduce a notion of abstract Lie group by means of the mapping which plays the role of the evolution operator. We show some basic properties of such groups very similar to the fundamentals of the infinite dimensional Lie theory. Next we give remarkable examples of abstract Lie groups which are not necessarily usual Lie groups. In particular, by making use of Yamabe theorem we prove that any locally compact topological group admits the structure of abstract Lie group and that the Lie algebra and the exponential mapping of it coincide with those determined by the Lie group structure.

  17. Emotional collectives: How groups shape emotions and emotions shape groups.

    Science.gov (United States)

    van Kleef, Gerben A; Fischer, Agneta H

    2016-01-01

    Group settings are epicentres of emotional activity. Yet, the role of emotions in groups is poorly understood. How do group-level phenomena shape group members' emotional experience and expression? How are emotional expressions recognised, interpreted and shared in group settings? And how do such expressions influence the emotions, cognitions and behaviours of fellow group members and outside observers? To answer these and other questions, we draw on relevant theoretical perspectives (e.g., intergroup emotions theory, social appraisal theory and emotions as social information theory) and recent empirical findings regarding the role of emotions in groups. We organise our review according to two overarching themes: how groups shape emotions and how emotions shape groups. We show how novel empirical approaches break important new ground in uncovering the role of emotions in groups. Research on emotional collectives is thriving and constitutes a key to understanding the social nature of emotions.

  18. ON COLEMAN OUTER AUTOMORPHISM GROUPS OF FINITE GROUPS

    Institute of Scientific and Technical Information of China (English)

    海进科; 李正兴

    2014-01-01

    Let G be a finite group and OutCol(G) the Coleman outer automorphism group of G(for the definition, see below). The question whether OutCol(G) is a p′-group naturally arises from the study of the normalizer problem for integral group rings, where p is a prime. In this article, some sufficient conditions for OutCol(G) to be a p′-group are obtained. Our results generalize some well-known theorems.

  19. Chromosomes of South American Bufonidae (Amphibia, Anura Chromosomes of South American Bufonidae (Amphibia, Anura

    Directory of Open Access Journals (Sweden)

    Brum Zorrilla N.

    1973-09-01

    Full Text Available Karyotypes of eight of South American Bufonidae were studied: B.ictericus, B. spinulosus spinulosus, B. arenarum, B. g. fernandezae, B. g. d'orbignyi, B. crucifer, B. paracnemis and B. marinus. In all species 2n = 22 chromosomes were found. Neither heteromorphic pairs of chromosomes nor bivalents with characteristic morphology and behavior of sex chromosomesduring male meiosis were observed in any species.Karyotypes of eight of South American Bufonidae were studied: B.ictericus, B. spinulosus spinulosus, B. arenarum, B. g. fernandezae, B. g. d'orbignyi, B. crucifer, B. paracnemis and B. marinus. In all species 2n = 22 chromosomes were found. Neither heteromorphic pairs of chromosomes nor bivalents with characteristic morphology and behavior of sex chromosomesduring male meiosis were observed in any species.

  20. Anomaly-safe discrete groups

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mu-Chun, E-mail: muchunc@uci.edu [Department of Physics and Astronomy, University of California, Irvine, CA 92697-4575 (United States); Fallbacher, Maximilian, E-mail: m.fallbacher@tum.de [Physik–Department T30, Technische Universität München, James–Franck–Straße 1, 85748 Garching (Germany); Ratz, Michael, E-mail: michael.ratz@tum.de [Physik–Department T30, Technische Universität München, James–Franck–Straße 1, 85748 Garching (Germany); Trautner, Andreas, E-mail: andreas.trautner@tum.de [Physik–Department T30, Technische Universität München, James–Franck–Straße 1, 85748 Garching (Germany); Excellence Cluster Universe, Boltzmannstraße 2, 85748 Garching (Germany); Vaudrevange, Patrick K.S., E-mail: patrick.vaudrevange@tum.de [Excellence Cluster Universe, Boltzmannstraße 2, 85748 Garching (Germany); TUM Institute for Advanced Study, Lichtenbergstraße 2a, 85748 Garching (Germany); Arnold Sommerfeld Center for Theoretical Physics, Ludwig–Maximilians–Universität München, Theresienstraße 37, 80333 München (Germany)

    2015-07-30

    We show that there is a class of finite groups, the so-called perfect groups, which cannot exhibit anomalies. This implies that all non-Abelian finite simple groups are anomaly-free. On the other hand, non-perfect groups generically suffer from anomalies. We present two different ways that allow one to understand these statements.

  1. Anomaly-safe discrete groups

    Directory of Open Access Journals (Sweden)

    Mu-Chun Chen

    2015-07-01

    Full Text Available We show that there is a class of finite groups, the so-called perfect groups, which cannot exhibit anomalies. This implies that all non-Abelian finite simple groups are anomaly-free. On the other hand, non-perfect groups generically suffer from anomalies. We present two different ways that allow one to understand these statements.

  2. 2010 Chemical Working Group Status

    Science.gov (United States)

    Reid, Concha M.

    2010-01-01

    The Steering Group for the Interagency Advanced Power Group (IAPG) held their business meeting on November 30-December 1st in McLean, Virginia. Status reports were presented from each of the IAPG's Working Groups. These charts contain a brief summary of the IAPG Chemical Working Group's activities during 2010 and its plans for 2011.

  3. About Hebei Jianxin Construction Group

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Hebei Jianxin Construction (Group) Ltd. was incorporated in August 1984. As the holding company, Hebei Jianxin Construction (Group)Ltd. along with five companies under its holding, such as Baoding New Generation Real Estate Development Co., Ltd. and Baoding New Generation Property Management Co., Ltd., formed Hebei Jianxin Architectural Group (hereafter, the Group).

  4. Short Conjugators in Solvable Groups

    CERN Document Server

    Sale, Andrew W

    2011-01-01

    We give an upper bound on the size of short conjugators in certain solvable groups. Diestel-Leader graphs, which are a horocyclic product of trees, are discussed briefly and used to study the lamplighter groups. The other solvable groups we look at can be recognised in a similar vein, as groups which act on a horocyclic product of well known spaces. These include the Baumslag-Solitar groups BS(1,q) and semidirect products of Z^n with Z^k. Results can also be applied to the conjugacy of parabolic elements in Hilbert modular groups and to elements in 3-manifold groups.

  5. Maximal subgroups of finite groups

    Directory of Open Access Journals (Sweden)

    S. Srinivasan

    1990-01-01

    Full Text Available In finite groups maximal subgroups play a very important role. Results in the literature show that if the maximal subgroup has a very small index in the whole group then it influences the structure of the group itself. In this paper we study the case when the index of the maximal subgroups of the groups have a special type of relation with the Fitting subgroup of the group.

  6. Interrelation of group, micro-group and interpersonal identities of employees in production groups

    Directory of Open Access Journals (Sweden)

    Sidorenkov A.V.

    2016-12-01

    Full Text Available The article represents the results of mathematical and statistical analysis of the links between the levels of the identity of employees (group, micro-group and interpersonal by three components (cognitive, affective and behavioral in 37 industrial groups with expertise in different fields. The significant linear relationship between micro-group and interpersonal identity (for all components, high linear relationship between group identity and micro-group identity (only for affective component and the lack of linear relationship between the components of inter- personal and group identity are revealed. Higher influence of group identity on micro-group (for all components and interpersonal identity (for cognitive and behavioral components is found out in the totality of intercorrelation between group, micro-group and interpersonal identities. Non-linear relationship between group and micro-group identity for all components is revealed. This non-linear relation indicates that increase in expressiveness of one of the components of group iden- tity leads to decrease in expressiveness of the respective component of micro-group identity. This effect occurs until definite moment, after which, on the contrary, further reinforcement of the components of group identity leads to the increase in expressiveness of micro-group identity. These established consistent patterns are interpreted in the article.

  7. Does group efficacy increase group identification? Resolving their paradoxical relationship

    NARCIS (Netherlands)

    van Zomeren, Martijn; Leach, Colin Wayne; Spears, Russell

    2010-01-01

    Although group identification and group efficacy are both important predictors of collective action against collective disadvantage, there is mixed evidence for their (causal) relationship. Meta-analytic and correlational evidence suggests an overall positive relationship that has been interpreted a

  8. Groups possessing extensive hierarchical decompositions

    CERN Document Server

    Januszkiewicz, T; Leary, I J

    2009-01-01

    Kropholler's class of groups is the smallest class of groups which contains all finite groups and is closed under the following operator: whenever $G$ admits a finite-dimensional contractible $G$-CW-complex in which all stabilizer groups are in the class, then $G$ is itself in the class. Kropholler's class admits a hierarchical structure, i.e., a natural filtration indexed by the ordinals. For example, stage 0 of the hierarchy is the class of all finite groups, and stage 1 contains all groups of finite virtual cohomological dimension. We show that for each countable ordinal $\\alpha$, there is a countable group that is in Kropholler's class which does not appear until the $\\alpha+1$st stage of the hierarchy. Previously this was known only for $\\alpha= 0$, 1 and 2. The groups that we construct contain torsion. We also review the construction of a torsion-free group that lies in the third stage of the hierarchy.

  9. Secure Group Communications for Large Dynamic Multicast Group

    Institute of Scientific and Technical Information of China (English)

    Liu Jing; Zhou Mingtian

    2003-01-01

    As the major problem in multicast security, the group key management has been the focus of research But few results are satisfactory. In this paper, the problems of group key management and access control for large dynamic multicast group have been researched and a solution based on SubGroup Secure Controllers (SGSCs) is presented, which solves many problems in IOLUS system and WGL scheme.

  10. Growth of Automorphism Groups of Relatively Free Groups

    Institute of Scientific and Technical Information of China (English)

    V. Drensky; A.I. Papistas

    2001-01-01

    We introduce a new growth function for automorphism groups of residually nilpotent relatively free groups Fn(V) and study its behavior. We prove that, under some natural restrictions, the growth of the group of tame automorphisms of Fn(V) is equal to the growth of the automorphism group of Fn(V), and coincides with the growth of the Lie algebra over Q associated with Fn (V). Applications of our techniques are given.

  11. Intensifying the Group Member's Experience Using the Group Log.

    Science.gov (United States)

    Valine, Warren J.

    1983-01-01

    Presents the use of a group log in which members analyze the content and process of each session using a suggested format. The log promotes dialogue between the leader and each group member and involves members more fully in the group process. Feedback indicates the log is valuable. (JAC)

  12. Re-Examining Group Development in Adventure Therapy Groups.

    Science.gov (United States)

    DeGraaf, Don; Ashby, Jeff

    1998-01-01

    Small-group development is an important aspect of adventure therapy. Supplementing knowledge of sequential stages of group development with knowledge concerning within-stage nonsequential development yields a richer understanding of groups. Integrating elements of the individual counseling relationship (working alliance, transference, and real…

  13. How Much "Group" Is There in Online Group Work?

    Science.gov (United States)

    Lowes, Susan

    2014-01-01

    The ability to work in groups across time and space has become a frequent requirement for the workplace and is increasingly common in higher education, but there is a surprising lack of research on how online groups work. This research applies analytic approaches used in studies of face-to-face classroom "talk" to multiple groups in two…

  14. The influence of ethnic group composition on focus group discussions

    National Research Council Canada - National Science Library

    Greenwood, Nan; Ellmers, Theresa; Holley, Jess

    2014-01-01

    ... of importance to them in their own words [2]. They are particularly useful for gaining insight from minority ethnic groups [1, 3] because of their sensitivity to cultural variables [2, 4]. One of the main differences between focus groups and one-to-one interviews is the interaction between participants. Focus group participants can...

  15. An Exploration of Group and Member Development in Experiential Groups

    Science.gov (United States)

    Ohrt, Jonathan H.; Prochenko, Yulia; Stulmaker, Hayley; Huffman, David; Fernando, Delini; Swan, Karrie

    2014-01-01

    In this phenomenological study, we explored 52 group members' development in experiential groups. Specifically, participants completed 10 weekly journal reflections about their experiences as members and also reflected on the group's overall development. Four overall themes--exploration, transition, working, closure--as well as multiple subthemes…

  16. Saving Face and Group Identity

    DEFF Research Database (Denmark)

    Eriksson, Tor; Mao, Lei; Villeval, Marie-Claire

    2015-01-01

    their self- but also other group members' image. This behavior is frequent even in the absence of group identity. When group identity is more salient, individuals help regardless of whether the least performer is an in-group or an out-group. This suggests that saving others' face is a strong social norm.......Are people willing to sacrifice resources to save one's and others' face? In a laboratory experiment, we study whether individuals forego resources to avoid the public exposure of the least performer in their group. We show that a majority of individuals are willing to pay to preserve not only...

  17. Group analysis of differential equations

    CERN Document Server

    Ovsiannikov, L V

    1982-01-01

    Group Analysis of Differential Equations provides a systematic exposition of the theory of Lie groups and Lie algebras and its application to creating algorithms for solving the problems of the group analysis of differential equations.This text is organized into eight chapters. Chapters I to III describe the one-parameter group with its tangential field of vectors. The nonstandard treatment of the Banach Lie groups is reviewed in Chapter IV, including a discussion of the complete theory of Lie group transformations. Chapters V and VI cover the construction of partial solution classes for the g

  18. Quantization on nilpotent Lie groups

    CERN Document Server

    Fischer, Veronique

    2016-01-01

    This book presents a consistent development of the Kohn-Nirenberg type global quantization theory in the setting of graded nilpotent Lie groups in terms of their representations. It contains a detailed exposition of related background topics on homogeneous Lie groups, nilpotent Lie groups, and the analysis of Rockland operators on graded Lie groups together with their associated Sobolev spaces. For the specific example of the Heisenberg group the theory is illustrated in detail. In addition, the book features a brief account of the corresponding quantization theory in the setting of compact Lie groups. The monograph is the winner of the 2014 Ferran Sunyer i Balaguer Prize.

  19. Group Lasso with Overlaps: the Latent Group Lasso approach

    CERN Document Server

    Obozinski, Guillaume; Vert, Jean-Philippe

    2011-01-01

    We study a norm for structured sparsity which leads to sparse linear predictors whose supports are unions of prede ned overlapping groups of variables. We call the obtained formulation latent group Lasso, since it is based on applying the usual group Lasso penalty on a set of latent variables. A detailed analysis of the norm and its properties is presented and we characterize conditions under which the set of groups associated with latent variables are correctly identi ed. We motivate and discuss the delicate choice of weights associated to each group, and illustrate this approach on simulated data and on the problem of breast cancer prognosis from gene expression data.

  20. Riemannian means on special euclidean group and unipotent matrices group.

    Science.gov (United States)

    Duan, Xiaomin; Sun, Huafei; Peng, Linyu

    2013-01-01

    Among the noncompact matrix Lie groups, the special Euclidean group and the unipotent matrix group play important roles in both theoretic and applied studies. The Riemannian means of a finite set of the given points on the two matrix groups are investigated, respectively. Based on the left invariant metric on the matrix Lie groups, the geodesic between any two points is gotten. And the sum of the geodesic distances is taken as the cost function, whose minimizer is the Riemannian mean. Moreover, a Riemannian gradient algorithm for computing the Riemannian mean on the special Euclidean group and an iterative formula for that on the unipotent matrix group are proposed, respectively. Finally, several numerical simulations in the 3-dimensional case are given to illustrate our results.

  1. Group performance and decision making.

    Science.gov (United States)

    Kerr, Norbert L; Tindale, R Scott

    2004-01-01

    Theory and research on small group performance and decision making is reviewed. Recent trends in group performance research have found that process gains as well as losses are possible, and both are frequently explained by situational and procedural contexts that differentially affect motivation and resource coordination. Research has continued on classic topics (e.g., brainstorming, group goal setting, stress, and group performance) and relatively new areas (e.g., collective induction). Group decision making research has focused on preference combination for continuous response distributions and group information processing. New approaches (e.g., group-level signal detection) and traditional topics (e.g., groupthink) are discussed. New directions, such as nonlinear dynamic systems, evolutionary adaptation, and technological advances, should keep small group research vigorous well into the future.

  2. Group discussion improves lie detection

    National Research Council Canada - National Science Library

    Nadav Klein; Nicholas Epley

    2015-01-01

    ... identify when a person is lying. These experiments demonstrate that the group advantage in lie detection comes through the process of group discussion, and is not a product of aggregating individual opinions...

  3. Neutral Hydrogen in Galaxy Groups

    CERN Document Server

    McKay, N P F; Brough, S; Forbes, D A; Barnes, D G

    2002-01-01

    We present preliminary results from a study of the neutral hydrogen (HI) properties of an X-ray selected sample of nearby loose galaxy groups. This forms part of a multi-wavelength investigation (X-ray, optical and radio) of the formation and evolution of galaxies within a group environment. Some initial findings of an ATNF Parkes Multibeam wide-area neutral hydrogen imaging survey of 17 nearby galaxy groups include two new, potentially isolated clouds of HI in the NGC 1052 and NGC 5044 groups and significant amounts of HI within the group virial radii of groups NGC 3557 and IC 1459 - two groups with complex X-ray structures that suggest they may still be in the act of virialisation. Here we present ATCA high-resolution synthesis-imaging follow-up observations of the distribution and kinematics of HI in these four groups.

  4. Differential calculi on finite groups

    CERN Document Server

    Castellani, L

    1999-01-01

    A brief review of bicovariant differential calculi on finite groups is given, with some new developments on diffeomorphisms and integration. We illustrate the general theory with the example of the nonabelian finite group S_3.

  5. On -supersolvability of finite groups

    Indian Academy of Sciences (India)

    Izabela Agata Malinowska

    2015-05-01

    A number of authors have studied the structure of a group under the assumption that some subgroups of are well located in . We will obtain some new criteria of -supersolvability and -nilpotency of groups.

  6. PRICE DISCRIMINATION THROUGH GROUP BUYING

    OpenAIRE

    2016-01-01

    This paper argues that when consumers are heterogeneous in group-buying costs, a monopolist seller may practice price discrimination through inducing certain consumers to participate in group buying. In contrast to the standard model, the optimal quantity/quality level for low valuation consumers without group buying is further distorted downward, whereas the levels for other consumers are socially optimal. Inducing group buying is more favorable when the proportion of high valuation consumer...

  7. Lie groups and automorphic forms

    CERN Document Server

    Ji, Lizhen; Xu, H W; Yau, Shing-Tung

    2006-01-01

    Lie groups are fundamental objects in mathematics. They occur naturally in differential geometry, algebraic geometry, representation theory, number theory, and other areas. Closely related are arithmetic subgroups, locally symmetric spaces and the spectral theory of automorphic forms. This book consists of five chapters which give comprehensive introductions to Lie groups, Lie algebras, arithmetic groups and reduction theories, cohomology of arithmetic groups, and the Petersson and Kuznetsov trace formulas.

  8. On The Harmonic Oscillator Group

    CERN Document Server

    Lopez, Raquel M; Vega-Guzman, Jose M

    2011-01-01

    We discuss the maximum kinematical invariance group of the quantum harmonic oscillator from a view point of the Ermakov-type system. The invariance group of generalized driven harmonic oscillator is shown to be isomorphic to the corresponding Schroedinger group of the free particle.

  9. Designing for informed group formation

    DEFF Research Database (Denmark)

    Nicolajsen, Hanne Westh; Juel Jacobsen, Alice; Riis, Marianne

    2012-01-01

    A new design ―project preparation‖ preparing for the group formation in problem based project work is proposed and investigated. The main problem is to overcome group formation based on existing relations. The hypothesis is that theme development and group formation are somewhat counterproductive...

  10. The Variety of Group Learning

    Institute of Scientific and Technical Information of China (English)

    HaoYanyan; YuZhihao

    2004-01-01

    With the rapid enrollment expansion in the recent years,the author feels it urgent to reform the traditional group work,and therefore to form a new and more effective pattern of group learning. The new of group word is based on the principles of cooperation and that of the task with the more flexible marking system.

  11. Group Cooperation in Outdoor Education

    Science.gov (United States)

    Matthews, Bruce E.

    1978-01-01

    Utilizing the Beatles' Yellow Submarine fantasy (e.g., the Blue Meanies), this outdoor education program is designed for sixth graders and special education students. Activities developed at the Cortland Resident Outdoor Education Camp include a series of group stress/challenge activities to be accomplished by everyone in the group, as a group.…

  12. Group Assessment and Structured Learning.

    Science.gov (United States)

    Lambert, Warren; And Others

    1980-01-01

    Two new techniques that were used with a group of seven blind, multiply handicapped young adults in a half-way house are described. Structured learning therapy is a social skills training technique and group assessment is a method of averaging psychological data on a group of clients to facilitate program planning based on client needs.…

  13. Internal communication in corporate groups

    OpenAIRE

    Grzesik, Katarzyna

    2015-01-01

    This chapter is dedicated to internal communication in corporate groups. It discusses internal communication systems operating in the explored corporate groups and their significance for effective human resources management in those organisations. The chapter presents both the theoretical analysis based on the results of literature studies, and empirical research carried out in the explored groups. Narodowe Centrum Nauki Katarzyna Grzesik

  14. Gestation group housing of sows

    NARCIS (Netherlands)

    Spoolder, H.A.M.; Vermeer, H.M.

    2015-01-01

    Group housing of gestating sows is currently replacing individual housing systems around the world. Modern group housing systems allow performance in groups to be equal to that in individual housing systems. A crucial element in the success of a housing system is the way in which it deals with

  15. Strategies for Successful Group Work

    Science.gov (United States)

    Nipp, Mary Beth; Palenque, Stephanie Maher

    The thought of group work, or CLC Groups often strikes fear and loathing in the hearts and minds of both students and instructors. According to Swan, Shen, and Hiltz (2006) collaborative work presents the possibilities of many difficulties including a largely unequal contribution of group participants, an inability of the students to manage the…

  16. Empowering Groups that Enable Play

    Science.gov (United States)

    Wilson, David Sloan; Marshall, Danielle; Iserhott, Hindi

    2011-01-01

    Creating play environments for children usually requires groups of adults working together. An extensive scientific literature describes how groups function to achieve shared goals in general terms, and groups attempting to empower play may find this literature useful. Design principles for managing natural resources, identified by Elinor Ostrom…

  17. group

    African Journals Online (AJOL)

    Results: The Suri have an old tradition of practicing child spacing. The reasons for .... to closely spaced births as in Bangladesh (11), and the constant threat of violence and ... increasing population and labor migration to urban areas, that often ...

  18. Locally minimal topological groups 1

    OpenAIRE

    Chasco, María Jesús; Dikranjan, Dikran N.; Außenhofer, Lydia; Domínguez, Xabier

    2015-01-01

    The aim of this paper is to go deeper into the study of local minimality and its connection to some naturally related properties. A Hausdorff topological group ▫$(G,tau)$▫ is called locally minimal if there exists a neighborhood ▫$U$▫ of 0 in ▫$tau$▫ such that ▫$U$▫ fails to be a neighborhood of zero in any Hausdorff group topology on ▫$G$▫ which is strictly coarser than ▫$tau$▫. Examples of locally minimal groups are all subgroups of Banach-Lie groups, all locally compact groups and all mini...

  19. Defining and Classifying Interest Groups

    DEFF Research Database (Denmark)

    Baroni, Laura; Carroll, Brendan; Chalmers, Adam;

    2014-01-01

    The interest group concept is defined in many different ways in the existing literature and a range of different classification schemes are employed. This complicates comparisons between different studies and their findings. One of the important tasks faced by interest group scholars engaged...... in large-N studies is therefore to define the concept of an interest group and to determine which classification scheme to use for different group types. After reviewing the existing literature, this article sets out to compare different approaches to defining and classifying interest groups with a sample...

  20. Stereotypes of Norwegian social groups.

    Science.gov (United States)

    Bye, Hege H; Herrebrøden, Henrik; Hjetland, Gunnhild J; Røyset, Guro Ø; Westby, Linda L

    2014-10-01

    We present a pilot study and two main studies that address the nature of stereotypes of social groups in Norway within the framework of the Stereotype Content Model (SCM). The first study focused on stereotypes of a wide range of groups across categories such as gender, age, religious conviction, socioeconomic and health status. The second study focused on stereotypes of immigrant groups. Participants (n = 244 and n = 63, respectively) rated the groups on perceived warmth, competence, status, and competition. Results from both studies support the applicability of the SCM in Norway and provides a unique insight into stereotypes of Norwegian social groups.

  1. Little Groups of Preon Branes

    CERN Document Server

    Mkrtchyan, H G

    2003-01-01

    Little groups for preon branes (i.e. configurations of branes with maximal (n-1)/n fraction of survived supersymmetry) for dimensions d=2,3,...,11 are calculated for all massless, and partially for massive orbits. For massless orbits little groups are semidirect product of d-2 translational group $T_{d-2}$ on a subgroup of (SO(d-2) $\\times$ R-invariance) group. E.g. at d=9 the subgroup is exceptional $G_2$ group. It is also argued, that 11d Majorana spinor invariants, which distinguish orbits, are actually invariant under d=2+10 Lorentz group. Possible applications of these results include construction of field theories in generalized space-times with brane charges coordinates, different problems of group's representations decompositions, spin-statistics issues.

  2. Little Groups of Preon Branes

    Science.gov (United States)

    MKRTCHYAN, H.; MKRTCHYAN, R.

    Little groups for preon branes (i.e. configurations of branes with maximal (n-1)/n fraction of survived supersymmetry) for dimensions d=2,3,…,11 are calculated for all massless, and partially for massive orbits. For massless orbits little groups are semidirect product of d-2 translational group Td-2 on a subgroup of (SO(d-2) × R-invariance) group. E.g. at d=9 the subgroup is exceptional G2 group. It is also argued, that 11D Majorana spinor invariants, which distinguish orbits, are actually invariant under d=2+10 Lorentz group. Possible applications of these results include construction of field theories in generalized spacetimes with brane charges coordinates, different problems of group's representations decompositions, spin-statistics issues.

  3. The "group" in obstetric psychoprophylaxis.

    Science.gov (United States)

    Volpe, B; Tenaglia, F; Fede, T; Cerutti, R

    1983-01-01

    In the practice of obstetric psychoprophylaxis every method employed considered always the group both from a psychological and a pedagogic point of view. Today the group of pregnant women (or couples) is considered under various aspects: - psychological: the group as a support for members with regard to maternal and parental emotional feelings; - anthropological: the group fills up an empty vital space and becomes a "rite de passage" from a state of social identity to another one; - social: the group is a significative cultural intermediary between health services and the women-patient. The knowledge of these aspects becomes an important methodological support for group conductors. We present an analysis of our experience with groups and how this has affected the Psychoprophylaxis in the last years.

  4. Ethnic Group Identification and Group Evaluation Among Minority and Majority Groups : Testing the Multiculturalism Hypothesis

    NARCIS (Netherlands)

    Verkuyten, Maykel J. A. M.

    2005-01-01

    Following social identity theory, the author hypothesized that members of minority groups are more likely than majority group members to endorse multiculturalism more strongly and assimilationist thinking less strongly. In addition, the multiculturalism hypothesis proposes that the more minority gro

  5. Ethnic group identification and group evaluation among minority and majority groups: testing the multiculturalism hypothesis.

    Science.gov (United States)

    Verkuyten, Maykel

    2005-01-01

    Following social identity theory, the author hypothesized that members of minority groups are more likely than majority group members to endorse multiculturalism more strongly and assimilationist thinking less strongly. In addition, the multiculturalism hypothesis proposes that the more minority groups endorse the ideology of multiculturalism (or assimilationism), the more (or less) likely they will be to identify with their ethnic in-group and to show positive in-group evaluation. In contrast, the more majority group members endorse multiculturalism (or assimilationism), the less (or more) likely they are to identify with their ethnic group and to show negative out-group evaluation. Results from 4 studies (correlational and experimental) provide support for this hypothesis among Dutch and Turkish participants living in the Netherlands.

  6. Terrorist Group Brands: Understanding Terrorist Group Strategies Through Brand Exposure

    Science.gov (United States)

    2016-06-01

    in the same 24-hour period, thereby making brand exposure a percentage of the global news market-share. The percentage is important because the... BRANDS : UNDERSTANDING TERRORIST GROUP STRATEGIES THROUGH BRAND EXPOSURE by Bradley S. Greaver June 2016 Thesis Advisor: Camber Warren...REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE TERRORIST GROUP BRANDS : UNDERSTANDING TERRORIST GROUP STRATEGIES THROUGH BRAND

  7. Finite Groups with Its Power Automorphism Groups Having Small Indices

    Institute of Scientific and Technical Information of China (English)

    Jun Xin WANG; Xiu Yun GUO

    2009-01-01

    In this paper,a finite group G with|Aut(G) : P(G)| = p or pq is determined,where P(G)is the power automorphism group of G,and p,q are distinct primes.Especially,we prove that a finite group G satisfies |Aut(G) : P(G)| = pq if and only if Aut(G)/P(G) (≈)S3.Also,some other classes of finite groups are investigated and classified,which are necessary for the proof of our main results.

  8. In-Group Versus Out-Group Source Memory.

    Science.gov (United States)

    Greenstein, Michael; Franklin, Nancy; Klug, Jessica

    2016-06-01

    A common finding in the source monitoring literature is that greater similarity impairs source discriminability. Experiments traditionally manipulate similarity overtly by describing or showing sources with explicitly differentiable features. However, people may also infer source characteristics themselves, which should also affect discriminability. Two studies examined inferred source characteristics by capitalizing on the out-group homogeneity effect, whereby in-group members are conceptualized as more diverse than out-group members. Participants learned about two sources who were described only as members of an in-group or an out-group and whose actions did not have higher a priori association with either group. Source memory was superior when participants believed the sources to be in-group members. This demonstrates that people spontaneously include inferred features with source representations and can capitalize on these features during source monitoring. Interestingly, information suggesting membership in one's in-group improved performance even for sources who had previously been considered out-group members (Experiment 2).

  9. Small group discussion: Students perspectives.

    Science.gov (United States)

    Annamalai, Nachal; Manivel, Rajajeyakumar; Palanisamy, Rajendran

    2015-08-01

    Various alternative methods are being used in many medical colleges to reinforce didactic lectures in physiology. Small group teaching can take on a variety of different tasks such as problem-solving, role play, discussions, brainstorming, and debate. Research has demonstrated that group discussion promotes greater synthesis and retention of materials. The aims of this study were to adopt a problem-solving approach by relating basic sciences with the clinical scenario through self-learning. To develop soft skills, to understand principles of group dynamics, and adopt a new teaching learning methodology. Experimental study design was conducted in Phase I 1(st) year medical students of 2014-2015 batch (n = 120). On the day of the session, the students were grouped into small groups (15 each). The session started with the facilitator starting off the discussion. Feedback forms from five students in each group was taken (n = 40). A five point Likert scale was used ranging from strongly agree to strongly disagree. Data were analyzed using IBM SPSS Statistics for Windows, Version 21.0. Armonk, NY: IBM Corp. Our results show that 70% of the students opined that small group discussion were interactive, friendly, innovative, built interaction between teacher and student. Small group discussion increased their thought process and helped them in better communication. The small group discussion was interactive, friendly, and bridged the gap between the teacher and student. The student's communication skills are also improved. In conclusion, small group discussion is more effective than the traditional teaching methods.

  10. Duality group actions on fermions

    Science.gov (United States)

    Pantev, Tony; Sharpe, Eric

    2016-11-01

    In this short paper we look at the action of T-duality and string duality groups on fermions, in maximally-supersymmetric theories and related theories. Briefly, we argue that typical duality groups such as SL(2 , ℤ) have sign ambiguities in their actions on fermions, and propose that pertinent duality groups be extended by ℤ2, to groups such as the metaplectic group. Specifically, we look at duality groups arising from mapping class groups of tori in M theory compactifications, T-duality, ten-dimensional type IIB S-duality, and (briefly) four-dimensional N = 4 super Yang-Mills, and in each case, propose that the full duality group is a nontrivial ℤ2 extension of the duality group acting on bosonic degrees of freedom, to more accurately describe possible actions on fermions. We also walk through U-duality groups for toroidal compactifications to nine, eight, and seven dimensions, which enables us to perform cross-consistency tests of these proposals.

  11. [Group cohesion: a concept analysis].

    Science.gov (United States)

    Lin, Yen-Ru; Chen, Yu-Jung; Tzeng, Wen-Chii; Chou, Kuei-Ru

    2007-10-01

    Group cohesion is considered an essential condition for achieving a successful treatment team. High cohesion groups more readily reach their goals, with group members also feeling more secure about their functions and contributions. In clinical practice, nurses use group teaching and group therapy to help patient and family members gain knowledge and skills related to illness treatment and recuperation. Effective group leadership helps minimize non-productive time and manpower and enhance interpersonal interaction. A further advantage of group cohesion is that the more effective administration of nursing programs that results can raise the profession level of staffs and reduce turnover. Walker and Avant (1995) employ concept analysis to use defining attributes in order to apply the same definition and communication to the same profession. The purpose of this paper was to apply this methodology to an analysis of group cohesion. Steps used include a review of the literature on conceptual definitions of group cohesion, a determination of defining attributes, model construction, identification of borderline, contrary, and related cases, and identification of antecedents and consequences and empirical tools. It is hoped that this analysis can help nursing staff to gain a better understanding of the concept of group cohesion and to apply such to clinical practice and nursing administration.

  12. Duality group actions on fermions

    CERN Document Server

    Pantev, T

    2016-01-01

    In this short paper we look at the action of T-duality and string duality groups on fermions, in maximally-supersymmetric theories and related theories. Briefly, we argue that typical duality groups such as SL(2,Z) have sign ambiguities in their actions on fermions, and propose that pertinent duality groups be extended by Z_2, to groups such as the metaplectic group. Specifically, we look at duality groups arising from mapping class groups of tori in M theory compactifications, T-duality, ten-dimensional type IIB S-duality, and (briefly) four-dimensional N=4 super Yang-Mills, and in each case, propose that the full duality group is a nontrivial Z_2 extension of the duality group acting on bosonic degrees of freedom, to more accurately describe possible actions on fermions. We also walk through U-duality groups for toroidal compactifications to nine, eight, and seven dimensions, which enables us to perform cross-consistency tests of these proposals.

  13. Group lending and the role of the group leader

    NARCIS (Netherlands)

    van Eijkel, R.; Hermes, C.L.M.; Lensink, B.W.

    2011-01-01

    This paper investigates strategic monitoring behavior within group lending. We show that monitoring efforts of group members differ in equilibrium due to the asymmetry between members in terms of future profits. In particular, we show that the entrepreneur with the highest future profits also puts i

  14. Logspace Computations in Coxeter Groups and Graph Groups

    CERN Document Server

    Diekert, Volker; Lohrey, Markus

    2012-01-01

    Computing normal forms in groups (or monoids) is in general harder than solving the word problem (equality testing). However, normal form computation has a much wider range of applications. It is therefore interesting to investigate the complexity of computing normal forms for important classes of groups. For Coxeter groups we show that the following algorithmic tasks can be solved by a deterministic Turing machine using logarithmic work space, only: 1. Compute the length of any geodesic normal form. 2. Compute the set of letters occurring in any geodesic normal form. 3. Compute the Parikh-image of any geodesic normal form in case that all defining relations have even length (i.e., in even Coxeter groups.) 4. For right-angled Coxeter groups we can do actually compute the short length normal form in logspace. (Note that short length normal forms are geodesic.) Next, we apply the results to right-angled Artin groups. They are also known as free partially commutative groups or as graph groups. As a consequence o...

  15. Good for the group? Explaining apparent group-level selection

    NARCIS (Netherlands)

    Smallegange, I.M.; Egas, M.

    2015-01-01

    The idea that group selection can explain adaptive trait evolution is still controversial. Recent empirical work proposes evidence for group-level adaptation in a social spider, but the findings can also be explained from an individual-level perspective. The challenge remains to identify situations

  16. Group reports. The recommendations proposed by the seven discussion groups

    NARCIS (Netherlands)

    NN,

    1989-01-01

    GROUP 1 — Discussion leader S.H. Sohmer — Organization and the ideal format of a large Flora (over 10,000 species) The Working Group first recognized that there are really two major categories of Flora projects serving quite different needs in the Malesian region: the local/national projects that

  17. The Local Group and other neighboring galaxy groups

    CERN Document Server

    Karachentsev, I D

    2004-01-01

    Over the last few years, rapid progress has been made in distance measurements for nearby galaxies based on the magnitude of the tip of red giant branch stars. Current CCD surveys with HST and large ground- based telescopes bring $\\sim$10%-accurate distances for roughly a hundred galaxies within 5 Mpc. The new data on distances to galaxies situated in (and around) the nearest groups: the Local Group, M81 group, CenA/M83 group, IC342/Maffei group, Sculptor filament, and Canes Venatici cloud allowed us to determine their total mass from the radius of the zero- velocity surface, $R_0$, which separates a group as bound against the homogeneous cosmic expansion. The values of $R_0$ for the virialized groups turn out to be close each other, in the range of 0.9 -- 1.3 Mpc. As a result, the total masses of the groups are close to each other, too, yielding total mass-to-blue luminosity ratios of 10 -- 40 $M_{\\sun}/L_{\\sun}$. The new total mass estimates are 3 -- 5 times lower than old virial mass estimates of these gro...

  18. Group Journaling: A Tool for Reflection, Fun and Group Development

    Science.gov (United States)

    Asfeldt, Morten

    2012-01-01

    Personal journaling is common practice in outdoor programs and is an important means of reflection and meaning-making. For over 20 years the author has used group journals to promote reflection and understanding, raise important questions, explore difficult issues, develop writing and speaking skills, and enhance group development. In this…

  19. Group theory and its applications

    CERN Document Server

    Thapa, Ram Kumar

    2019-01-01

    Every molecule possesses symmetry and hence has symmetry operations and symmetry elements. From symmetry properties of a system we can deduce its significant physical results. Consequently it is essential to operations of a system forms a group. Group theory is an abstract mathematical tool that underlies the study of symmetry and invariance. By using the concepts of symmetry and group theory, it is possible to obtain the members of complete set of known basis functions of the various irreducible representations of the group. I practice this is achieved by applying the projection operators to linear combinations of atomic orbital (LCAO) when the valence electrons are tightly bound to the ions, to orthogonalized plane waves (OPW) when valence electrons are nearly free and to the other given functions that are judged to the particular system under consideration. In solid state physics the group theory is indispensable in the context of finding the energy bands of electrons in solids. Group theory can be applied...

  20. Non-Abelian Pseudocompact Groups

    Directory of Open Access Journals (Sweden)

    W. W. Comfort

    2016-01-01

    Full Text Available Here are three recently-established theorems from the literature. (A (2006 Every non-metrizable compact abelian group K has 2|K| -many proper dense pseudocompact subgroups. (B (2003 Every non-metrizable compact abelian group K admits 22|K| -many strictly finer pseudocompact topological group refinements. (C (2007 Every non-metrizable pseudocompact abelian group has a proper dense pseudocompact subgroup and a strictly finer pseudocompact topological group refinement. (Theorems (A, (B and (C become false if the non-metrizable hypothesis is omitted. With a detailed view toward the relevant literature, the present authors ask: What happens to (A, (B, (C and to similar known facts about pseudocompact abelian groups if the abelian hypothesis is omitted? Are the resulting statements true, false, true under certain natural additional hypotheses, etc.? Several new results responding in part to these questions are given, and several specific additional questions are posed.

  1. Countably determined compact abelian groups

    CERN Document Server

    Dikranjan, Dikran

    2008-01-01

    For an abelian topological group G let G^* be the dual group of all continuous characters endowed with the compact open topology. A subgroup D of G determines G if the restriction homomorphism G^* --> D^* of the dual groups is a topological isomorphism. Given a scattered compact subset X of an infinite compact abelian group G such that |X|group, we show that the set of all characters which send X into U has the same size as G^*. (Here w(G) denotes the weight of G.) As an application, we prove that a compact abelian group determined by its countable subgroup must be metrizable. This gives a negative answer to questions of Comfort, Hernandez, Macario, Raczkowski and Trigos-Arrieta, as well as provides short proofs of main results established in three manuscripts by these authors.

  2. Group discussion improves lie detection.

    Science.gov (United States)

    Klein, Nadav; Epley, Nicholas

    2015-06-16

    Groups of individuals can sometimes make more accurate judgments than the average individual could make alone. We tested whether this group advantage extends to lie detection, an exceptionally challenging judgment with accuracy rates rarely exceeding chance. In four experiments, we find that groups are consistently more accurate than individuals in distinguishing truths from lies, an effect that comes primarily from an increased ability to correctly identify when a person is lying. These experiments demonstrate that the group advantage in lie detection comes through the process of group discussion, and is not a product of aggregating individual opinions (a "wisdom-of-crowds" effect) or of altering response biases (such as reducing the "truth bias"). Interventions to improve lie detection typically focus on improving individual judgment, a costly and generally ineffective endeavor. Our findings suggest a cheap and simple synergistic approach of enabling group discussion before rendering a judgment.

  3. Modelling group dynamic animal movement

    DEFF Research Database (Denmark)

    Langrock, Roland; Hopcraft, J. Grant C.; Blackwell, Paul G.

    2014-01-01

    Group dynamic movement is a fundamental aspect of many species' movements. The need to adequately model individuals' interactions with other group members has been recognised, particularly in order to differentiate the role of social forces in individual movement from environmental factors. However......, to date, practical statistical methods which can include group dynamics in animal movement models have been lacking. We consider a flexible modelling framework that distinguishes a group-level model, describing the movement of the group's centre, and an individual-level model, such that each individual...... makes its movement decisions relative to the group centroid. The basic idea is framed within the flexible class of hidden Markov models, extending previous work on modelling animal movement by means of multi-state random walks. While in simulation experiments parameter estimators exhibit some bias...

  4. Groups, graphs and random walks

    CERN Document Server

    Salvatori, Maura; Sava-Huss, Ecaterina

    2017-01-01

    An accessible and panoramic account of the theory of random walks on groups and graphs, stressing the strong connections of the theory with other branches of mathematics, including geometric and combinatorial group theory, potential analysis, and theoretical computer science. This volume brings together original surveys and research-expository papers from renowned and leading experts, many of whom spoke at the workshop 'Groups, Graphs and Random Walks' celebrating the sixtieth birthday of Wolfgang Woess in Cortona, Italy. Topics include: growth and amenability of groups; Schrödinger operators and symbolic dynamics; ergodic theorems; Thompson's group F; Poisson boundaries; probability theory on buildings and groups of Lie type; structure trees for edge cuts in networks; and mathematical crystallography. In what is currently a fast-growing area of mathematics, this book provides an up-to-date and valuable reference for both researchers and graduate students, from which future research activities will undoubted...

  5. Designing for informed group formation

    DEFF Research Database (Denmark)

    Nicolajsen, Hanne Westh; Juel Jacobsen, Alice; Riis, Marianne

    2012-01-01

    A new design ―project preparation‖ preparing for the group formation in problem based project work is proposed and investigated. The main problem is to overcome group formation based on existing relations. The hypothesis is that theme development and group formation are somewhat counterproductive....... Following research based design methodology an experiment separating the two was initiated.This was to provide for more openness and creativity in contrast to a design in which existing relations seem predominant.......A new design ―project preparation‖ preparing for the group formation in problem based project work is proposed and investigated. The main problem is to overcome group formation based on existing relations. The hypothesis is that theme development and group formation are somewhat counterproductive...

  6. Group supervision for general practitioners

    DEFF Research Database (Denmark)

    Galina Nielsen, Helena; Sofie Davidsen, Annette; Dalsted, Rikke;

    2013-01-01

    AIM: Group supervision is a sparsely researched method for professional development in general practice. The aim of this study was to explore general practitioners' (GPs') experiences of the benefits of group supervision for improving the treatment of mental disorders. METHODS: One long...... considered important prerequisites for disclosing and discussing professional problems. CONCLUSION: The results of this study indicate that participation in a supervision group can be beneficial for maintaining and developing GPs' skills in dealing with patients with mental health problems. Group supervision......-established supervision group was studied closely for six months by observing the group sessions, and by interviewing GPs and their supervisors, individually and collectively. The interviews were recorded digitally and transcribed verbatim. The data were analysed using systematic text condensation. RESULTS: The GPs found...

  7. All finitely presentable groups from link complements and Kleinian groups

    CERN Document Server

    Aitchison, Iain R

    2010-01-01

    We prove that every finitely presentable group G arises as the fundamental group of an orientable 3-complex obtained from a hyperbolic link complement, by coning each boundary torus of the link exterior to a distinct point. We define the closed-link-genus, clg(G), of any finitely presentable group G, which completely characterizes fundamental groups of closed orientable 3-manifolds: clg(G)=0 if and only if G is the fundamental group of a closed orientable 3-manifold. Moreover clg(G) gives an upper bound for the concept `genus(G)' of genus defined earlier by Aitchison and Reeves, and in turn is bounded by the minimal number of relations among all finite presentations of G.

  8. Taxonomy Working Group Final Report

    Science.gov (United States)

    Parsons, Vickie S.; Beil, Robert J.; Terrone, Mark; Barth, Timothy S.; Panontin, Tina L.; Wales, Roxana; Rackley, Michael W.; Milne, James S.; McPherson, John W.; Dutra, Jayne E.; Shaw, Larry C.

    2009-01-01

    The purpose of the Taxonomy Working Group was to develop a proposal for a common taxonomy to be used by all NASA projects in the classifying of nonconformances, anomalies, and problems. Specifically, the group developed a recommended list of data elements along with general suggestions for the development of a problem reporting system to better serve NASA's need for managing, reporting, and trending project aberrant events. The Group's recommendations are reported in this document.

  9. Cascade Product of Permutation Groups

    OpenAIRE

    Egri-Nagy, Attila; Nehaniv, Chrystopher L.

    2013-01-01

    We define the cascade product of permutation groups as an external product, an explicit construction of substructures of the iterated wreath product that are much smaller than the full wreath product. This construction is essential for computational implementations of algebraic hierarchical decompositions of finite automata. We show how direct, semidirect, and wreath products and group extensions can all be expressed as cascade products, and analyse examples of groups that can be constructed ...

  10. Group Connectivity and Group Colorings of Graphs - A Survey

    Institute of Scientific and Technical Information of China (English)

    Hong-Jian LAI; Xiangwen LI; Yehong SHAO; Mingquan ZHAN

    2011-01-01

    In 1950s, Tutte introduced the theory of nowhere-zero flows as a tool to investigate the coloring problem of maps, together with his most fascinating conjectures on nowhere-zero flows. These have been extended by Jaeger et al. In 1992 to group connectivity, the nonhomogeneous form of nowhere-zero flows. Let G be a 2-edge-connected undirected graph, A be an (additive) abelian group and A* = A - {0}. The graph G is A-connected if G has an orientation D(G) such that for every each vertex v ∈ V(G), the total amount of f-values on the edges directed out from v minus the total amount of f-values on the edges directed into v is equal to b(v). The group coloring of a graph arises from the dual concept of group connectivity. There have been lots of investigations on these subjects.This survey provides a summary of researches on group connectivity and group colorings of graphs. It contains the following sections.1. Nowhere-zero Flows and Group Connectivity of Graphs 2. Complete Families and A-reductions 3. Reductions with Edge-deletions, Vertex-deletions and Vertex-splitting 4. Group Colorings as a Dual Concept of Group Connectivity 5. Brooks Theorem, Its Variations and Dual Forms 6. Planar Graphs 7. Group Connectivity of Graphs 7.1 Highly Connected Graphs and Collapsible Graphs 7.2 Degrees Conditions 7.3 Complementary Graphs 7.4 Products of Graphs 7.5 Graphs with Diameter at Most 2 7.6 Line Graphs and Claw-Free Graphs 7.7 Triangular Graphs 7.8 Claw-decompositions and All Tutte-orientations

  11. Group decision-making: Factors that affect group effectiveness

    Directory of Open Access Journals (Sweden)

    Juliana Osmani

    2016-03-01

    Full Text Available Organizations are operating in a dynamic and turbulent environment. In these conditions, they have to make decisions for new problems or situations. Most of decisions are therefore non-programmed and unstructured, accompanied by risk and uncertainty. Moreover, the problems and situations are complex. All organizations are oriented towards group decisionmaking processes, as useful tools to cope with uncertainty and complexity. Apart from the necessity, companies are turning towards participatory processes also to benefit from the important advantages that these processes offer. Organizations have realized the importance of group decision-making processes to contribute to the creation of sustainable competitive advantages. Main objective of this paper is to show that group decision-making processes do not offer guarantee for good decisions, because the effectiveness of group is affected by many factors. So, the first thing done in this paper is discussing about the benefits and limitations that accompany the use of groups with decision-making purpose. Afterwards, we stop on the different factors that influence the group’s ability to make good decisions. The aim is to emphasize that regardless of the many advantages of groups, some factors as group size, type of communication within the group, leadership style, the norms, the differentiation of roles and statuses, cohesion and compliance degree should be the main elements to keep into consideration because they affect the effectiveness of group. In this regard, is discussed how such factors influence the quality of decision and then we try to draw some conclusions that can improve and make better and easier group decision-making processes.

  12. Strategic Groups and Banks’ Performance

    Directory of Open Access Journals (Sweden)

    Gregorz Halaj

    2009-06-01

    Full Text Available The theory of strategic groups predicts the existence of stable groups of companies that adopt similar business strategies. The theory also predicts that groups will differ in performance and in their reaction to external shocks. We use cluster analysis to identify strategic groups in the Polish banking sector. We find stable groups in the Polish banking sector constituted after the year 2000 following the major privatisation and ownership changes connected with transition to the mostly-privately-owned banking sector in the late 90s. Using panel regression methods we show that the allocation of banks to groups is statistically significant in explaining the profitability of banks. Thus, breaking down the banks into strategic groups and allowing for the different reaction of the groups to external shocks helps in a more accurate explanation of profits of the banking sector as a whole.Therefore, a more precise ex ante assessment of the loss absorption capabilities of banks is possible, which is crucial for an analysis of banking sector stability. However, we did not find evidence of the usefulness of strategic groups in explaining the quality of bank portfolios as measured by irregular loans over total loans, which is a more direct way to assess risks to financial stability.

  13. Bosonization and Lie Group Structure

    CERN Document Server

    Ha, Yuan K

    2015-01-01

    We introduce a concise quantum operator formula for bosonization in which the Lie group structure appears in a natural way. The connection between fermions and bosons is found to be exactly the connection between Lie group elements and the group parameters. Bosonization is an extraordinary way of expressing the equation of motion of a complex fermion field in terms of a real scalar boson in two dimensions. All the properties of the fermion field theory are known to be preserved under this remarkable transformation with substantial simplification and elucidation of the original theory, much like Lie groups can be studied by their Lie algebras.

  14. Automorphism groups of some algebras

    Institute of Scientific and Technical Information of China (English)

    PARK; Hong; Goo; LEE; Jeongsig; CHOI; Seul; Hee; NAM; Ki-Bong

    2009-01-01

    The automorphism groups of algebras are found in many papers. Using auto-invariance, we find the automorphism groups of the Laurent extension of the polynomial ring and the quantum n-plane (respectively, twisting polynomial ring) in this work. As an application of the results of this work, we can find the automorphism group of a twisting algebra. We define a generalized Weyl algebra and show that the generalized Weyl algebra is simple. We also find the automorphism group of a generalized Weyl algebra. We show that the generalized Weyl algebra Am,m+n is the universal enveloping algebra of the generalized Witt algebra W(m,m + n).

  15. Twisted conjugacy in braid groups

    CERN Document Server

    González-Meneses, Juan

    2011-01-01

    In this note we solve the twisted conjugacy problem for braid groups, i.e. we propose an algorithm which, given two braids $u,v\\in B_n$ and an automorphism $\\phi \\in Aut (B_n)$, decides whether $v=(\\phi (x))^{-1}ux$ for some $x\\in B_n$. As a corollary, we deduce that each group of the form $B_n \\rtimes H$, a semidirect product of the braid group $B_n$ by a torsion-free hyperbolic group $H$, has solvable conjugacy problem.

  16. Character theory of finite groups

    CERN Document Server

    Isaacs, I Martin

    2006-01-01

    Character theory is a powerful tool for understanding finite groups. In particular, the theory has been a key ingredient in the classification of finite simple groups. Characters are also of interest in their own right, and their properties are closely related to properties of the structure of the underlying group. The book begins by developing the module theory of complex group algebras. After the module-theoretic foundations are laid in the first chapter, the focus is primarily on characters. This enhances the accessibility of the material for students, which was a major consideration in the

  17. Visual Grouping by Neural Oscillators

    CERN Document Server

    Yu, Guoshen

    2008-01-01

    Distributed synchronization is known to occur at several scales in the brain, and has been suggested as playing a key functional role in perceptual grouping. State-of-the-art visual grouping algorithms, however, seem to give comparatively little attention to neural synchronization analogies. Based on the framework of concurrent synchronization of dynamic systems, simple networks of neural oscillators coupled with diffusive connections are proposed to solve visual grouping problems. Multi-layer algorithms and feedback mechanisms are also studied. The same algorithm is shown to achieve promising results on several classical visual grouping problems, including point clustering, contour integration and image segmentation.

  18. Abstract commensurators of braid groups

    OpenAIRE

    Leininger, Christopher J; Margalit, Dan

    2005-01-01

    Let B_n be the braid group on n strands, with n at least 4, and let Mod(S) be the extended mapping class group of the sphere with n+1 punctures. We show that the abstract commensurator of B_n is isomorphic to a semidirect product of Mod(S) with a group we refer to as the transvection subgroup, Tv(B_n). We also show that Tv(B_n) is itself isomorphic to a semidirect product of an infinite dimensional rational vector space with the multiplicative group of nonzero rational numbers.

  19. Automorphism groups of some algebras

    Institute of Scientific and Technical Information of China (English)

    PARK Hong Goo; LEE Jeongsig; CHOI Seul Hee; CHEN XueQing; NAM Ki-Bong

    2009-01-01

    The automorphism groups of algebras are found in many papers. Using auto-invariance, we find the automorphism groups of the Laurent extension of the polynomial ring and the quantum n-plane (respectively, twisting polynomial ring) in this work. As an application of the results of this work, we can find the automorphism group of a twisting algebra. We define a generalized Weyl algebra and show that the generalized Weyl algebra is simple. We also find the automorphism group of a generalized Weyl algebra. We show that the generalized Weyl algebra Am,m+n is the universal enveloping algebra of the generalized Witt algebra W(m, m+n).

  20. Membership Rules - LHCRRB Scrutiny Group

    CERN Document Server

    2017-01-01

    The LHC Resources Scrutiny Group was created in 2001 to review and scrutinize the M&O cost estimates of the LHC Collaborations. The Scrutiny Group first met on 23 August 2001 and reported to the RRBs at its 13th Plenary meeting, in October 2001 (RRB-D-2001-8). The Scrutiny Group operates according to the procedures set out in Annex 12 of the MoUs for the M&O of the LHC experiments. This document lists the Rules of Procedure that apply to the M&O Scrutiny Group