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Sample records for atta sexdens rubropilosa

  1. Population genetics of atta sexdens rubropilosa (hymenoptera: formicidae)

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    Belizário Cantagalli, Liriana; Aparecida Mangolin, Claudete; Colla Ruvolo Takasusuki, Maria Claudia

    2013-01-01

    The genetic variability of Atta sexdens rubropilosa leaf-cutting ants collected from five brazilian localities was evaluated with PCR-RAPD technique. We used 15 primers producing 148 fragments of which 123 (83,11 %) contained polymorphisms. The estimated Shannon index was 0.3836 ± 0.2335 showing that these ants possess high genetic diversity. The GST value was 0,2372 and PT = 0,184, indicating that the analyzed populations are moderately differentiated and 82 % of the variation obtained occur...

  2. Genética de poplaciones de Atta sexdens rubropilosa (Hymenoptera: Formicidae) POPULATION GENETICS OF Atta sexdens rubropilosa (HYMENOPTERA: FORMICIDAE)

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    LIRIANA BELIZÁRIO CANTAGALLI; CLAUDETE APARECIDA MANGOLIN; MARIA CLAUDIA COLLA RUVOLO TAKASUSUKI

    2013-01-01

    La variabilidad genética de las hormigas Atta sexdens rubropilosa colectadas en cinco lugares distintos de Brasil fueron evaluados por la técnica PCR-RAPD. Un total de 15 primers produjeron 148 fragmentos, de los cuales 123 fueron polimórficos, lo que corresponden al 83,11 %. La estimación de la diversidad genética por el índice de Shannon fue 0,3836 y el desviación estándar fue de ± 0,2335. Estos valores demuestran una alta diversidad genética. El valor de G ST fue 0,2372 y ΦPT = 0,184 l...

  3. Genética de poplaciones de Atta sexdens rubropilosa (Hymenoptera: Formicidae POPULATION GENETICS OF Atta sexdens rubropilosa (HYMENOPTERA: FORMICIDAE

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    LIRIANA BELIZÁRIO CANTAGALLI

    2013-04-01

    Full Text Available La variabilidad genética de las hormigas Atta sexdens rubropilosa colectadas en cinco lugares distintos de Brasil fueron evaluados por la técnica PCR-RAPD. Un total de 15 primers produjeron 148 fragmentos, de los cuales 123 fueron polimórficos, lo que corresponden al 83,11 %. La estimación de la diversidad genética por el índice de Shannon fue 0,3836 y el desviación estándar fue de ± 0,2335. Estos valores demuestran una alta diversidad genética. El valor de G ST fue 0,2372 y ΦPT = 0,184 lo que indica que las poblaciones están moderadamente diferenciadas y que el 82 % de la variación obtenida se produce dentro de las poblaciones. Aunque la prueba de Mantel ha demostrado una correlación entre la distancia genética y geográfica se observó que Ivatuba e Itambé (33,8 km tiene una pequeña distancia geográfica y la mayor distancia genética. La distancia inferior genética fue estimada para Maringá e Ivatuba pero estas localidades cuentan con una distancia geográfica pequeña (42,3 km, lo que indica que no hay barreras para el apareamiento entre los reproductores en estas poblaciones. El alto valor de polimorfismo (83,11 % y la capacidad de emparejamiento entre las poblaciones presentes en las regiones estudiadas, indican que esta especie de hormiga cortadora está bien adaptada a la región, y deben ser desarrollados programas integrados de control si se convierten en plagas.The genetic variability of Atta sexdens rubropilosa leaf-cutting ants collected from five brazilian localities was evaluated with PCR-RAPD technique. We used 15 primers producing 148 fragments of which 123 (83.11 % contained polymorphisms. The estimated Shannon index was 0.3836 ± 0.2335 showing that these ants possess high genetic diversity. The G ST value was 0.2372 and ΦPT = 0.184, indicating that the analyzed populations are moderately differentiated and 82 % of the variation obtained occur within populations. Although Mantel's test had shown correlation

  4. Eficiência de isca formicida aplicada sobre o monte de terra solta de ninhos de Atta sexdens rubropilosa (Hymenoptera: Formicidae Efficiency of a granulated bait applied over the nests of Atta sexdens rubropilosa (Hymenoptera: Formicidae

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    Ronald Zanetti

    2003-06-01

    Full Text Available Avaliou-se a eficiência de uma isca granulada à base de sulfluramida (0,3% aplicada em olheiros situados sobre o monte de terra solta, em comparação com o sistema convencional de aplicação nos olheiros fora desses montes, no combate a Atta sexdens rubropilosa Forel, 1908 (Hymenoptera: Formicidae. Os tratamentos consistiram da aplicação de uma isca granulada à base de sulfluramida (0,3%, a 8 g/m² do formigueiro aparente, em olheiros situados sobre ou fora do monte de terra solta. Foram utilizados 192 formigueiros de A. sexdens rubropilosa, distribuídos nesses dois tratamentos. Foram avaliadas a porcentagem de carregamento e de devolução dessa isca, aos dois dias após sua aplicação, e a eficiência do combate, aos 150 dias após, por sondagem (uma a cada metro quadrado de fomigueiro. A porcentagem de carregamento da isca granulada foi maior quando aplicada fora do monte de terra solta (100,00% do que sobre ele (89,58%, porém a eficiência de controle foi semelhante, com 89,58% para o primeiro e 90,27% para o segundo tratamento, respectivamente. Por isto, em razão do menor custo e facilidade, recomenda-se aplicar esta isca sobre os montes de terra solta de formigueiros de A. sexdens rubropilosa.The efficiency of a granulated bait formulated with sulfluramid (0.3% for the control of Atta sexdens rubropilosa Forel, 1908 (Hymenoptera: Formicidae was evaluated. Treatments consisted of applying this bait at a dose of 8g/m² from the ant nest. This bait was applied near entrances over ant nests (treatment T1 or near those outside these nests (treatment T2. A total of 192 ant nests of A. sexdens rubropilosa were used in the two treatments. Percentage of transport and devolution of the bait by A. sexdens rubropilosa was evaluated two days after its application and control efficiency, 150 days after application. Percentage of bait transport was higher when applied outside the ant nest (100.00% than over it (89.5%. However, control

  5. Atratividade de Atta sexdens rubropilosa por plantas de eucalipto atacadas previamente ou não por Thyrinteina arnobia Atta sexdens rubropilosa attractiveness to eucalyptus plants previously attacked or not by Thyrinteina arnobia

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    Hamilton Gomes de Oliveira

    2004-03-01

    Full Text Available O sistema de defesa induzido das plantas é ativado após a ocorrência do dano provocado por um herbívoro. O objetivo deste trabalho foi avaliar se plantas de eucalipto (Eucalyptus grandis atacadas previamente por lagartas de Thyrinteina arnobia tornam-se resistentes ao corte de operárias de Atta sexdens rubropilosa. Não houve diferença significativa no tempo gasto por operárias dessa formiga em iniciar o corte em plantas atacadas ou não. Porém, houve diferença significativa no tamanho de fragmentos cortados. Concluiu-se que plantas previamente atacadas tornam-se menos atrativas para A. sexdens rubropilosa devido à ativação do seu sistema de defesa induzido.The induced defense system of plants is activated after the occurrence of damage by a herbivore. The objective of this work was to evaluate whether plants of Eucalyptus grandis previously attacked by larvae of Thyrinteina arnobia become resistant to cutting by the leaf-cutting ant Atta sexdens rubropilosa. There was no significant difference in the lapse of time spent by the workers of this ant before they started cutting plants previously attacked or not. There was significant reduction in the size of leaf fragments cut by the ants. It was concluded that plants previously attacked were less attractive to the leaf cutter due to the activation of their induced defense system.

  6. Ricinus communis and Jatropha curcas (Euphorbiaceae) seed oil toxicity against Atta sexdens rubropilosa (Hymenoptera: Formicidae).

    Science.gov (United States)

    Alonso, E C; Santos, D Y A C

    2013-04-01

    Leaf-cutting ants are the main herbivores in the New World tropics. Although the toxicity of seed oils against these ants has been poorly investigated, previous results revealed that seed oils exert considerable toxic activity against these insects. This paper analyzes the toxic action and deterrent properties of castor oil, Ricinus communis L., and physic nut oil, Jatropha curcas L., against workers of the leaf-cutting ant Atta sexdens rubropilosa reared in laboratory. Toxic effect was analyzed by feeding insects artificial diets supplemented with different oil concentrations and direct contact with the two oils. Deterrent activity was assessed by measuring the frequency of attendance to diets during the first 48 h of the ingestion bioassay. Castor oil at 10 and 30 mg/ml and physic nut oil at 5, 10, and 30 mg/ml were toxic by ingestion. In the direct contact bioassay, toxicity was observed for physic nut oil at 0.1 and 0.2 mg/ml, whereas castor oil exerted toxic effects only when the highest concentration was applied. Also, castor oil had a more pronounced deterrent effect against the leaf-cutting ant, compared with physic nut oil. Methods to apply these oils to control these insects are discussed. PMID:23786062

  7. Seleção de isolados de Metarhizium anisopliae e Beauveria bassiana patogênicos a soldados de Atta bisphaerica e Atta sexdens rubropilosa em condições de laboratório Selection of Metarhizium anisopliae and Beauveria bassiana isolates pathogenic to Atta bisphaerica and Atta sexdens rubropilosa soldiers under laboratory conditions

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    Alzimiro Marcelo Conteiro Castilho; Marcelo Elias Fraga; Elen de Lima Aguiar-Menezes; Carlos Alberto da Rocha Rosa

    2010-01-01

    As formigas do gênero Atta são pragas importantes de diversas culturas agrícolas, pastagens e reflorestamentos. Os fungos entomopatogênicos estão entre os fatores naturais de mortalidade dessas formigas e por isso apresentam potencial para serem usados no controle biológico dessa praga. O presente trabalho teve como objetivo selecionar isolados de Metarhizium anisopliae e Beauveria bassiana patogênicos a soldados de Atta bisphaerica e Atta sexdens rubropilosa em condições de laboratório. Para...

  8. Influence of physical and chemical factors during foraging and culture of the symbiont fungus in Atta sexdens rubropilosa (Hymenoptera: Formicidae)

    Institute of Scientific and Technical Information of China (English)

    SANDRA S. VERZA; LUIZ C. FORTI; JULIANE F. S. LOPES; ROBERTO S.CAMARGO; CARLOS A. O. MATOS

    2007-01-01

    The aim of this paper is to investigate the influence of physical and chemical factors on transport and use of substrate for Atta sexdens rubropilosa workers. Three types of rectangular fragments were used to study the physical influence factors: filter paper with paraffin, filter paper without paraffin and polyester film. To study the chemical factors, some fragments were impregnated with organic extract of orange albedo, others were soaked with soybean oil and for the remaining ones nothing was applied. The following parameters were evaluated: (i) attractiveness of substrate for transport and number of loading workers per treatment; (ii) foraged material incorporation; (iii) rejection by numbers of fragments deposited in the garbage or beside the fungus garden. All the polyester film fragments carried out to the fungus garden were subsequently rejected. We verified that chemical factors of the substrate were more quickly detected by the workers, whereas physical factors were used as a criterion in the decision-making to reject or accept the substrate collected:

  9. Forrageamento por Atta sexdens rubropilosa Forel, 1908 (hymenoptera: formicidae a campo em mudas de eucalipto pulverizadas ou imersas em soluções de extrato pirolenhoso Cutting activity by Atta sexdens rubropilosa Forel, 1908 (hymenoptera: formicidae on eucalyptus seedlings treated by irrigation or immersion with solutions of liquid pyroligneous

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    Alan Souza-Silva

    2007-08-01

    Full Text Available Bioensaios foram realizados a campo no Município de Olhos D'Água, Minas Gerais, para verificar a ação indireta do extrato pirolenhoso sobre Atta sexdens rubropilosa Forel, 1908 (Hymenoptera: Formicidae. Mudas de eucalipto prontas para o plantio foram pulverizadas ou imersas em soluções de água e extrato pirolenhoso, nas concentrações de 0,1; 0,2; 0,5; 1,0 ou 2,0%, sendo a testemunha constituída por água. Essas mudas foram plantadas a 10 cm de distância de uma trilha ativa de A. sexdens rubropilosa, próxima ao formigueiro-sede, e oferecidas em bioensaios com ou sem chance de escolha. Foi avaliada a porcentagem de forrageamento de A. sexdens rubropilosa, a cada 24 horas, durante duas semanas; e a cada 15 dias, até três meses. Foi, também, avaliada a longevidade das mudas a campo a cada 15 dias, por um período de três meses. O extrato pirolenhoso, entre 0,1 e 2%, favorece entre 57,67 e 100% o forrageamento de A. sexdens rubropilosa por mudas de eucalipto tratadas via irrigação ou imersão. A longevidade das mudas varia entre seis e 45 dias. A dosagem de adubação influencia o forrageamento de formigas-cortadeiras, pois mudas tratadas com 100% da adubação recomendada sofrem maior atividade de corte, entre 80 e 100%, por A. sexdens rubropilosa, do que mudas tratadas com metade da adubação. A. sexdens rubropilosa é capaz de reconhecer diferentes substratos, selecionando os que podem suprir as deficiências nutricionais da sua colônia.The effect of liquid pyroligneous on eucalyptus seedling cutting by Atta sexdens rubropilosa Forel, 1908 (Hymenoptera: Formicidae was evaluated in field conditions in Olhos D'Água, Minas Gerais, Brazil. Seedlings of 45 days of age received concentrated fertilization and the pyroligneous extract by irrigation or immersion in different concentrations (0%, 0,1%; 0,2%; 0,5%; 1% or 2%. Treated seedlings were planted 10 cm from active trails of A. sexdens rubropilosa, being offered in bioassays with

  10. CUSTO COMPARATIVO DE CONTROLE À FORMIGA CORTADEIRA Atta sexdens rubropilosa Forel 1908, EMPREGANDO-SE ISCAS GRANULADAS COMERCIAIS E UMA ISCA EXPERIMENTAL COMPARATIVE COST CONTROL OF Atta sexdens rubropilosa FOREL 1908 USING COMMERCIAL GRAIN BAITS AND AN EXPERIMENTAL BAIT

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    Antônio Lopes da Silva

    2007-09-01

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    Realizou-se um experimento de controle à formiga cortadeira Atta sexdens rubropilosa FOREL 1908, nos campos da Universidade Federal de Goiás (dezembro de 1972, com a finalidade de comparar o custo de controle por sauveiro, utilizando-se uma isca granulada experimental “EAV-041-A” idealizada pelo autor, com outras iscas existentes no mercado. Foram realizados 4 tratamentos (Mirex, Isca Shell, EAV-041-A e Agroceres na base de 10 g de cada isca por m² de sauveiro, em 5 repetições, constando cada parcela de 3 formigueiros, perfazendo um total de 60. O delineamento foi inteiramente ao acaso. Para a análise econômica dos resultados, foram utilizados os fatores: custo da isca, sua eficiência percentual e o valor da mão-de-obra requerida, para se determinar o custo médio de controle de um sauveiro extinto. Pelos valores calculados, como resultado, obteve-se o custo médio por sauveiro extinto na seguinte ordem: com a isca “EAV-04l-A” custou Cr$ 2,27; com a “Isca Shell” Cr$ 3,41; com “Agroceres” Cr$ 4,29 e com “Mirex” Cr$ 5,44, evidenciando a economia em favor da "EAV-041-A", tendo em vista o seu menor custo por quilograma (Na época em que os cálculos foram realizados, o valor cambial do Dólar era de Cr$ 6,00.

    An Experiment was conducted using a clorimated experimental bait called EAV-041-A. This experiment was conducted to determine the efficiency of EAV-041-A using the leaf-cutting ant Atta sexdens rubropilosa as the test. The experiment was executed in Goiânia, Goiás, comparing it with the commercial baits: Mirex, Isca Shell and Agroceres AG-005. Results obtained showed Mirex was superior giving 93.30% control of the nests, EAV-041-A 80.00% and Isca Shell and Agroceres both qave 73.30% control. Total cost of application was calculated based on price of the bait on

  11. Características químicas do lixo de formigueiros de Atta sexdens rubropilosa (Hymenoptera: Formicidae mantidos com diferentes substratos Chemical characteristics of nest refuse of Atta sexdens rubropilosa (Hymenoptera: Formicidae reared with different substrates

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    Marcelo Braga Bueno Guerra

    2007-10-01

    Full Text Available As saúvas (Atta spp. estão amplamente distribuídas pelo continente Sul-Americano e são consideradas importantes componentes do ecossistema neotropical. Diversos estudos têm demonstrado o efeito de formigueiros no enriquecimento do solo e na facilitação ao estabelecimento de espécies vegetais. Possivelmente o enriquecimento do solo seja devido ao acúmulo de matéria orgânica decomposta em câmaras de descarte (lixo no interior das colônias. Entretanto, pouco se sabe sobre a composição química do lixo de formigas cortadeiras. O objetivo do presente trabalho foi comparar os teores de nutrientes do lixo produzido por colônias de Atta sexdens rubropilosa Forel (Hymenoptera: Formicidae, em laboratório, mantidas com folhas de duas espécies de plantas. Os tratamentos foram dois tipos de substrato (Acalypha sp. ou Bauhinia sp., repetidos quatro vezes. Oito colônias foram divididas em dois grupos (n = 4, e cada grupo foi mantido com apenas um tratamento. Após 30 dias de experimento, as amostras de folhas e lixo foram secas em estufa (70 ºC e submetidas à digestão ácida, para determinação das concentrações de N, P, K, S, Ca e Mg. Diferenças nas concentrações dos macronutrientes entre os tratamentos (lixo ou folha foram comparadas por meio de ANOVA e teste T. As concentrações de nutrientes no lixo foram sempre maiores do que nas folhas, independentemente da espécie cortada. Folhas de Acalypha sp. apresentaram concentrações significativamente maiores do que folhas de Bauhinia sp. com relação aos teores de P, Ca, Mg e S; entretanto, as concentrações do lixo em todos os formigueiros foram muito próximas, indicando incorporação adicional de nutrientes por meio do fungo, excreções e, ou, cadáveres no lixo. Esses resultados indicam que, independentemente do substrato cortado, o lixo produzido apresenta maiores concentrações de nutrientes do que as folhas, sendo importante locus de reciclagem de nutrientes no

  12. Desenvolvimento in vitro do fungo simbionte de Atta sexdens rubropilosa Forel, 1908 (Hymenoptera: Formicidae) em meio de cultura com diferentes extratos vegetais Development in vitro of the symbiotic fungus of Atta sexdens rubropilosa Forel, 1908 (Hymenoptera: Formicidae) in culture medium with different plant extracts

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    Marcelo Dias de Souza; Otávio Peres Filho; Sidney Fernando Caldeira; Alberto Dorval; Nilton José Sousa

    2012-01-01

    O objetivo deste estudo foi avaliar o desenvolvimento in vitro de Leucoagaricus gongylophorus, fungo simbionte de Atta sexdens rubropilosa, em meio de cultura acrescido com extratos de 24 espécies vegetais. O fungo foi inoculado no meio BDA, acrescido com os extratos vegetais, além de quatro controles, em placas de Petri. As placas foram mantidas em câmaras climatizadas à temperatura de 25±1°C no escuro, por um período de 42 dias. O crescimento do fungo foi avaliado semanalmente através do di...

  13. Seleção de isolados de Metarhizium anisopliae e Beauveria bassiana patogênicos a soldados de Atta bisphaerica e Atta sexdens rubropilosa em condições de laboratório Selection of Metarhizium anisopliae and Beauveria bassiana isolates pathogenic to Atta bisphaerica and Atta sexdens rubropilosa soldiers under laboratory conditions

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    Alzimiro Marcelo Conteiro Castilho

    2010-06-01

    Full Text Available As formigas do gênero Atta são pragas importantes de diversas culturas agrícolas, pastagens e reflorestamentos. Os fungos entomopatogênicos estão entre os fatores naturais de mortalidade dessas formigas e por isso apresentam potencial para serem usados no controle biológico dessa praga. O presente trabalho teve como objetivo selecionar isolados de Metarhizium anisopliae e Beauveria bassiana patogênicos a soldados de Atta bisphaerica e Atta sexdens rubropilosa em condições de laboratório. Para a avaliação da patogenicidade, foram utilizados oito isolados de M. anisopliae e seis de B. bassiana. O experimento foi conduzido em DIC, sendo a parcela composta por um grupo de 10 soldados por espécie de formiga, sendo utilizadas três repetições por tratamento. Para cada isolado, três grupos de soldados foram pulverizados com suspensão de 1,0 x 10(8 conídios ml-1 e mantidos em câmara úmida (25±1°C, 80±1% de UR e no escuro sem alimentação, sendo a mortalidade verificada diariamente. Dos 14 isolados testados, quatro de M. anisopliae e quatro de B. bassiana foram patogênicos aos soldados de ambas as espécies de formigas. A virulência foi avaliada para os isolados que causaram mortalidade igual ou maior a 50%. Para cada isolado, suspensões contendo 1,0 x 10(6 a 1,0 x 10(11 conídios ml-1 foram pulverizadas sobre três grupos de 10 soldados e igualmente acondicionados como no teste de patogenicidade. A porcentagem de mortalidade foi calculada a cada 24 horas para determinação do TL50. O isolado ENA04 de M. anisopliae foi mais patogênico, causando mais de 80% de mortalidade nos primeiros três dias após a inoculação, apresentou maior capacidade de esporular nos cadáveres dos soldados e foi o mais virulento para os soldados de A. bisphaerica, com um TL50 de 1,15 dias. Todos os isolados patogênicos aos soldados de A. sexdens rubropilosa foram igualmente virulentos.The ants of the genus Atta are important pests of several

  14. Forrageamento por Atta sexdens rubropilosa Forel, 1908 (hymenoptera: formicidae) a campo em mudas de eucalipto pulverizadas ou imersas em soluções de extrato pirolenhoso Cutting activity by Atta sexdens rubropilosa Forel, 1908 (hymenoptera: formicidae) on eucalyptus seedlings treated by irrigation or immersion with solutions of liquid pyroligneous

    OpenAIRE

    Alan Souza-Silva; Ronald Zanetti

    2007-01-01

    Bioensaios foram realizados a campo no Município de Olhos D'Água, Minas Gerais, para verificar a ação indireta do extrato pirolenhoso sobre Atta sexdens rubropilosa Forel, 1908 (Hymenoptera: Formicidae). Mudas de eucalipto prontas para o plantio foram pulverizadas ou imersas em soluções de água e extrato pirolenhoso, nas concentrações de 0,1; 0,2; 0,5; 1,0 ou 2,0%, sendo a testemunha constituída por água. Essas mudas foram plantadas a 10 cm de distância de uma trilha ativa de A. sexdens rubro...

  15. Determinação do fator de conversão em colônias de Atta sexdens rubropilosa (Hymenoptera: Formicidae e sua relação com a qualidade do material vegetal cortado Determination of the conversion factor in colonies of Atta sexdens rubropilosa (Hymenoptera: Formicidae and its relationship with the quality of harvested leaf substrate

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    Leandro Sousa-Sou

    2007-02-01

    Full Text Available As formigas cortadeiras (Atta e Acromyrmex são consideradas importantes pragas na agricultura e silvicultura, mas pouco se sabe sobre os reais danos dessas espécies. Uma forma bastante difundida de avaliação do dano é por meio do cálculo da taxa de conversão, dividindo-se o peso do material cortado pelo peso de lixo produzido pelas colônias. Foi levantada a hipótese de que a qualidade do substrato cortado pode influenciar no forrageamento das operárias, alterando a taxa de conversão e dificultando as estimativas de dano. A taxa de conversão de oito colônias de Atta sexdens rubropilosa Forel (Hymenoptera: Formicidae foi calculada com duas espécies vegetais com diferentes concentrações de lignina e celulose, para testar essa hipótese. Colônias mantidas com folhas de baixa qualidade (razão lignina/celulose elevada tiveram maior forrageamento e produziram mais lixo. Entretanto, a taxa de conversão das colônias foi semelhante com essas duas plantas (média = 1,54. Esse valor está dentro da variação encontrada para outras espécies no campo (1,5-1,8, indicando um fator semelhante de conversão entre os gêneros Atta e Acromyrmex. O consumo médio de material vegetal, em termos de pesos seco e fresco, de uma colônia de A. sexdens rubropilosa com 4.500 operárias, foi estimado em 520 e 1.100 g/ano, respectivamente.Leaf-cutting ants (Atta and Acromyrmex are important pests in agriculture and forestry, although few data exist on the actual damage caused by these species. A model used to evaluate damage by leaf-cutting ants are estimates of the conversion factor, which is the ratio between the weight of material cut by the ants and the refuse produced by the colonies. The hypothesis that substrate quality influences foraging by workers, modifying the conversion factor and impairing damage estimates was put forward. To test this hypothesis, the conversion factor was calculated for eight colonies of Atta sexdens rubropilosa Forel

  16. Lipid and energy contents in the bodies of queens of Atta sexdens rubropilosa Forel (Hymenoptera, Formicidae: pre-and post-nuptial flight

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    Ricardo Toshio Fujihara

    2012-03-01

    Full Text Available The nuptial flight allows males and females to meet and copulate and both need energy to perform this activity. Before leaving the nest, males and females are well nourished and ready to mate. However, little is known about the lipid and energy contents in females before the nuptial flight (virgins and after it (mated females. In this work we measured lipid concentrations in relation to body weight in these individuals. Our results showed that 16.82% of the bodies of young virgin females one month before mating flight are composed of lipids, contrasting with the 32.62% lipid content in mated females who had not excavated their nest yet, and 32.88% in those who had. The energy content measured for virgin females was 2942.63 J, contrasting with 6110.01 J for queens before excavating the nest and 5677.51 J after excavation. Based on our results, we conclude that the body mass, and therefore the lipid and energy contents in the bodies of Atta sexdens rubropilosa queens double during the last month before the nuptial flight. This energy resource is fundamental to the activities required during the nuptial flight, digging the nest and the founding of the colony.

  17. Características biológicas e comportamentais de Neodohrniphora elongata Brown (Diptera, Phoridae, um parasitóide da saúva Atta sexdens rubropilosa Forel (Hymenoptera, Formicidae Biological and behavioral characteristics of Neodohrniphora elongata Brown (Diptera, Phoridae, a parasitic fly of the leaf-cutting ant Atta sexdens rubropilosa Forel (Hymenoptera, Formicidae

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    Marcos A. L. Bragança

    2009-12-01

    Full Text Available Foram investigadas as características da biologia e comportamento do forídeo Neodohrniphora elongata Brown, 2001 em relação às operárias do hospedeiro Atta sexdens rubropilosa Forel, 1908. Vinte e quatro fêmeas de N. elongata coletadas no campo foram liberadas, uma por vez, em uma cuba de observação interposta entre um ninho de A. sexdens rubropilosa e uma arena de forrageamento. As moscas realizaram de quatro a cinco vezes mais investidas sem sucesso contra as formigas do que ataques efetivos, quando elas ovipositaram na cabeça das operárias. Houve ataques em 426 operárias e desenvolvimento da larva do parasitóide na cápsula cefálica de 63,8% delas, sendo que emergiram 218 moscas. N. elongata ovipositou nas maiores operárias, ou seja, naquelas com largura da cápsula cefálica de 2,9 ± 0,4 mm, o que parece ser importante para o desenvolvimento do parasitóide, pois o fracasso na formação de pupas ou a não emergência do adulto ocorreram principalmente em formigas com largura da cápsula inferior a 2,9 mm. As moscas que emergiram em laboratório tiveram maior longevidade quando alimentadas com solução de mel 10% do que com solução de mel 50% ou somente água destilada. As fêmeas que emergiram no laboratório exibiram os mesmos comportamentos de voo e ataque das fêmeas do campo, mas não foi possível obter parasitóides de segunda geração. Estudos adicionais devem ser realizados para investigar a adequação de fontes naturais de carboidratos e proteínas sobre a longevidade e reprodução de N. elongata, visando à multiplicação deste e de outros forídeos de saúvas em laboratório.Characteristics of the biology and behavior of the phorid Neodohrniphora elongata Brown, 2001 in relation to workers of the host Atta sexdens rubropilosa Forel, 1908 were studied. Twenty-four field-collected females of N. elongata were released singly inside an observation chamber placed between a nest of A. sexdens rubropilosa and a

  18. Preferência de saúva limão, Atta sexdens rubropilosa Forel, 1908 (Hymenoptera, formicidae a diferentes espécies florestais, em condições de laboratório.

    Directory of Open Access Journals (Sweden)

    Otávio Peres Filho

    2010-08-01

    Full Text Available Avaliou-se a preferência de saúva limão, Atta sexdens rubropilosa Forel, 1908, para 41 espécies florestais nativas e exóticas, em condições de laboratório. As espécies mais transportadas foram gmelina (Gmelina arborea, leucena (Leucaena leucocephala, pau-ferro (Caesalpinia ferrea, albizia (Albizia lebbeck e orelha-de-negro (Enterolobium contortisiliquum e as menos transportadas foram eucalipto (Eucalyptus grandis, jequitibá (Cariniana strellensis e mutamba (Guazuma tomentosa.

  19. Preferência de saúva limão, Atta sexdens rubropilosa Forel, 1908 (Hymenoptera, formicidae) a diferentes espécies florestais, em condições de laboratório.

    OpenAIRE

    Otávio Peres Filho; Alberto Dorval; Evônio Berti Filho

    2010-01-01

    Avaliou-se a preferência de saúva limão, Atta sexdens rubropilosa Forel, 1908, para 41 espécies florestais nativas e exóticas, em condições de laboratório. As espécies mais transportadas foram gmelina (Gmelina arborea), leucena (Leucaena leucocephala), pau-ferro (Caesalpinia ferrea), albizia (Albizia lebbeck) e orelha-de-negro (Enterolobium contortisiliquum) e as menos transportadas foram eucalipto (Eucalyptus grandis), jequitibá (Cariniana strellensis) e mutamba (Guazuma tomentosa).

  20. PREFERÊNCIA DE SAÚVA LIMÃO, Atta sexdens rubropilosa Forel, 1908 (HYMENOPTERA, FORMICIDAE) A DIFERENTES ESPÉCIES FLORESTAIS, EM CONDIÇÕES DE LABORATÓRIO

    OpenAIRE

    Otávio Peres Filho; Alberto Dorval; Evônio Berti Filho

    2002-01-01

    Avaliou-se a preferência de saúva limão, Atta sexdens rubropilosa Forel, 1908, para 41 espécies florestais nativas e exóticas, em condições de laboratório. As espécies mais transportadas foram gmelina (Gmelina arborea), leucena (Leucaena leucocephala), pau-ferro (Caesalpinia ferrea), albizia (Albizia lebbeck) e orelha-de-negro (Enterolobium contortisiliquum) e as menos transportadas foram eucalipto (Eucalyptus grandis), jequitibá (Cariniana strellensis) e mutamba (Guazuma tomentosa ).

  1. PREFERÊNCIA DE SAÚVA LIMÃO, Atta sexdens rubropilosa Forel, 1908 (HYMENOPTERA, FORMICIDAE A DIFERENTES ESPÉCIES FLORESTAIS, EM CONDIÇÕES DE LABORATÓRIO

    Directory of Open Access Journals (Sweden)

    Otávio Peres Filho

    2002-08-01

    Full Text Available Avaliou-se a preferência de saúva limão, Atta sexdens rubropilosa Forel, 1908, para 41 espécies florestais nativas e exóticas, em condições de laboratório. As espécies mais transportadas foram gmelina (Gmelina arborea, leucena (Leucaena leucocephala, pau-ferro (Caesalpinia ferrea, albizia (Albizia lebbeck e orelha-de-negro (Enterolobium contortisiliquum e as menos transportadas foram eucalipto (Eucalyptus grandis, jequitibá (Cariniana strellensis e mutamba (Guazuma tomentosa .

  2. Lipid and energy contents in the bodies of queens of Atta sexdens rubropilosa Forel (Hymenoptera, Formicidae: pre-and post-nuptial flight

    Directory of Open Access Journals (Sweden)

    Ricardo Toshio Fujihara

    2012-03-01

    Full Text Available The nuptial flight allows males and females to meet and copulate and both need energy to perform this activity. Before leaving the nest, males and females are well nourished and ready to mate. However, little is known about the lipid and energy contents in females before the nuptial flight (virgins and after it (mated females. In this work we measured lipid concentrations in relation to body weight in these individuals. Our results showed that 16.82% of the bodies of young virgin females one month before mating flight are composed of lipids, contrasting with the 32.62% lipid content in mated females who had not excavated their nest yet, and 32.88% in those who had. The energy content measured for virgin females was 2942.63 J, contrasting with 6110.01 J for queens before excavating the nest and 5677.51 J after excavation. Based on our results, we conclude that the body mass, and therefore the lipid and energy contents in the bodies of Atta sexdens rubropilosa queens double during the last month before the nuptial flight. This energy resource is fundamental to the activities required during the nuptial flight, digging the nest and the founding of the colony.O vôo nupcial permite que machos e fêmeas se encontrem e copulem. Para isso, tanto o macho quanto a fêmea precisam de energia para efetuar tal atividade. Antes de partir do ninho de origem, machos e fêmeas estão bem nutridos e prontos para o acasalamento. Mas pouco se conhece sobre o teor de lipídeos e conteúdo energético pré-vôo nupcial (fêmeas virgens e pós-vôo nupcial (fêmeas acasaladas. Nossos resultados indicam que as fêmeas virgens apresentaram 16,82% de lipídeos em seu corpo, enquanto as rainhas (fêmeas acasaladas que não escavaram 32,62%, e as que escavaram 32,88%. O conteúdo energético foi de 2942,63 J para as fêmeas virgens, 6110,01 J para rainhas sem escavação e 5677,51 J para aquelas que escavaram. Com base nos resultados obtidos, concluí-se que as rainhas de

  3. Desenvolvimento in vitro do fungo simbionte de Atta sexdens rubropilosa Forel, 1908 (Hymenoptera: Formicidae em meio de cultura com diferentes extratos vegetais Development in vitro of the symbiotic fungus of Atta sexdens rubropilosa Forel, 1908 (Hymenoptera: Formicidae in culture medium with different plant extracts

    Directory of Open Access Journals (Sweden)

    Marcelo Dias de Souza

    2012-09-01

    Full Text Available O objetivo deste estudo foi avaliar o desenvolvimento in vitro de Leucoagaricus gongylophorus, fungo simbionte de Atta sexdens rubropilosa, em meio de cultura acrescido com extratos de 24 espécies vegetais. O fungo foi inoculado no meio BDA, acrescido com os extratos vegetais, além de quatro controles, em placas de Petri. As placas foram mantidas em câmaras climatizadas à temperatura de 25±1°C no escuro, por um período de 42 dias. O crescimento do fungo foi avaliado semanalmente através do diâmetro da colônia. Os resultados mostraram que o fungo simbionte dessas formigas apresenta um crescimento diferenciado em relação aos extratos fornecidos nas placas, sendo que o meio acrescido com os extratos de arica (Physocalymma scaberrimum, cerejeira (Amburana acreana, cedro (Cedrela fissilis, timbó (Magonia pubescens, leucena (Leucaena leucocephala e mogno (Swietenia macrophylla prejudicaram o desenvolvimento. No entanto, os extratos de genipapo (Genipa americana, seringueira (Heveaa brasiliensis, ingá (Inga edulis e cambará (Vochysia divergens apresentaram melhores condições de desenvolvimento para o fungo simbionte.The objective of this study was to evaluate the in vitro development of Leucoagaricus gongylophorus, the symbiotic fungus of Atta sexdens rubropilosa in culture medium added with extracts of 24 plant species. The fungus was inoculated in PDA added with vegetables extracts and four controls, in Petri dishes. The dishes were maintained in climate chambers at temperature of 25±1°C in the dark, to period of 42 days. The fungal growth was evaluated weekly by diameter of the colony. The results showed that the symbiotic fungus of these ants has differentiated growth when compared to the extracts provided in the dishes, and the medium supplemented with extracts of aricá (Physocalymma scaberrimum, cerejeira (Amburana acreana, cedro (Cedrela fissilis, timbó (Magonia pubescens, leucena (Leucaena leucocephala e mogno (Swietenia

  4. Energetic cost of digging behavior in workers of the leaf-cutting ant Atta sexdens (Fabricius)

    OpenAIRE

    Roberto da Silva Camargo; Juliane F. S. Lopes; Luiz Carlos Forti

    2013-01-01

    Energetic cost of digging behavior in workers of the leaf-cutting ant Atta sexdens (Fabricius). During nest excavation, leaf-cutting ant workers undergo reduction in their body reserve, particularly carbohydrates. In order to estimate the energetic cost of digging, groups of 30 workers of the leaf-cutting ant Atta sexdens were sealed in a hermetic chamber for 24, 48 and 72 hours, with and without soil for digging, and had the CO2 concentration measured using respirometric chambers as well as ...

  5. Fungos Filamentosos Associados às Espécies Atta sexdens (Linnaeus e Atta laevigata (F. Smith (Hymenoptera: Formicidae

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    Aline Dornelas

    2016-04-01

    Abstract. Leaf-cutting ants, Atta and Acromyrmex genera, are considered major pests in a neotropical agroforestry system because they cut plant material that will serve as food for the symbiotic fungus cultivated by them. Several fungi naturally occurring in the soil can be found associated with leaf-cutting ants, many of them are demonstrably entomopathogenic. However, these agents have not been used as biological control of leaf-cutting ants. The aim of this study was to isolate and to identify filamentous fungi associated with forage workers of Atta sexdens (Linnaeus and Atta laevigata (F. Smith and to test their pathogenicity against workers from laboratory colonies. To isolate filamentous fungi, it was collected a total of 180 forage workers (30 in each colony in six field colonies, 90 of A. sexdens and 90 workers of A. laevigata. Six fungi species from A. sexdens were isolated and identified: Metarhizium anisopliae (Metchnikoff Sorokin, Aspergillus flavus Link, Acremonium sp. 1, Aspergillus sp. 1, Colletotrichum sp. and Acremonium sp. 2. In A. laevigata, it was found four species: Mucor sp., Aspergillus flavus, Fusarium solani (Martius Saccardo, Aspergillus niger van Tieghem. Three of these fungi were selected for pathogenicity tests against workers of the leaf-cutting ant A. sexdens: A. flavus, A. niger and M. anisopliae. The LT50 (time to cause 50% mortality of workers in tests with A. niger and M. anisopliae were five days and significantly lower than the control group. Therefore, further tests should proceed with those isolates to demonstrate their potential use in the biological control of leaf-cutting ants.

  6. Patogenicidade de isolados de três fungos entomopatogênicos a soldados de Atta sexdens sexdens (Linnaeus, 1758 (Hymenoptera : Formicidae Pathogenicity of isolates of three entomopathogenic fungi against soldiers of Atta sexdens sexdens (Linnaeus, 1758 (Hymenoptera : Formicidae

    Directory of Open Access Journals (Sweden)

    Elisângela de Souza Loureiro

    2005-08-01

    Full Text Available As formigas cortadeiras atacam diversas culturas agrícolas, pastagens e os reflorestamentos, atuando sobre muitas espécies vegetais. O presente trabalho teve por objetivo avaliar a patogenicidade dos fungos Beauveria bassiana (isolados AM 9 e JAB 06, Metarhizium anisopliae (isolados E 9 e AL e Paecilomyces farinosus (isolados CG 189 e CG 195 a soldados de Atta sexdens sexdens, em condições de laboratório. Após a coleta em formigueiro isento de produtos fitossanitários, exemplares de soldados foram cuidadosamente separados em grupos de oito indivíduos e, a seguir, banhados em suspensões contendo 1,0 x 10(6, 1,0 x 10(7, 1,0 x 10(8 e 1,0 x 10(9 conídios/mL de cada isolado. Em seguida, cada grupo de formigas foi transferido para unidades de câmara úmida e mantido, sem alimentação, a 27 ± 1 ºC. A mortalidade foi verificada diariamente. Os três fungos se mostraram eficientes patógenos, pois provocaram alta mortalidade, matando mais que 80% dos soldados nos quatro primeiros dias após a inoculação. Os melhores isolados foram JAB 06 e AL, na concentração de 1,0 x 10(9 con./mL. Os isolados JAB 06, AL, CG 195 apresentaram maior capacidade de esporular nos cadáveres das formigas e os tempos letais decresceram com o aumento da concentração de conídios usada.Leaf-cutting ants attack several crops, pastures and the planted forests, acting on numerous vegetable species. The present work aimed to evaluate the pathogenicity of the fungi Beauveria bassiana (isolates AM 9 and JAB 06, Metarhizium anisopliae (isolates E 9 and Al and Paecilomyces farinosus (isolates CG 189 and CG 195 against soldiers of Atta sexdens sexdens, in laboratory conditions. These fungi were inoculated on soldiers after collection in nests without pesticides application. Specimens of soldiers were separated in groups of eight insects, which were bathed in suspensions containing 1.0 x 10(6, 1.0 x 10(7, 1.0 x 10(8 and 1.0 x 10(9 conidia/ml. Following the bath, each

  7. Energetic cost of digging behavior in workers of the leaf-cutting ant Atta sexdens (Fabricius

    Directory of Open Access Journals (Sweden)

    Roberto da Silva Camargo

    2013-12-01

    Full Text Available Energetic cost of digging behavior in workers of the leaf-cutting ant Atta sexdens (Fabricius. During nest excavation, leaf-cutting ant workers undergo reduction in their body reserve, particularly carbohydrates. In order to estimate the energetic cost of digging, groups of 30 workers of the leaf-cutting ant Atta sexdens were sealed in a hermetic chamber for 24, 48 and 72 hours, with and without soil for digging, and had the CO2 concentration measured using respirometric chambers as well as volume of soil excavated (g. As expected, the worker groups that carried out soil excavation expelled more carbon dioxide than the groups that did not excavate. Therefore, a worker with body mass of 9.65 ± 1.50 mg dug in average 0.85 ± 0.27 g of soil for 24 hours, consuming ca. 0.58 ± 0.23 J. In this study, we calculate that the energetic cost of excavation per worker per day in the experimental set-up was ca. 0.58 J.

  8. Ultrastructure and physiology of the CO2 sensitive sensillum ampullaceum in the leaf-cutting ant Atta sexdens

    OpenAIRE

    Kleineidam, Christoph; Romani, Roberto; Tautz, Jürgen; Isidoro, Nunzio

    2000-01-01

    The sensilla ampullacea on the apical antennomere of the leaf cutting ant Atta sexdens were investigated regarding both their responses to CO2 and their ultrastructure. By staining the sensillum during recording, we confirmed that the sensilla ampullacea are responsible for CO2 perception. We showed that the sensory neurons of the sensilla ampullacea are continuously active without adaptation during stimulation with CO2 (test duration: 1 h). This feature should enable ants to assess the absol...

  9. Atta sexdens (L.) (Hymenoptera: Formicidae) demography in the Colombian Amazon: an evaluation of the palatable forage hypothesis.

    Science.gov (United States)

    van Gils, Heike A J A; Gómez, Lilliam E; Gaigl, Andreas

    2011-08-01

    This study tested expectations of the palatable forage hypothesis for Atta sexdens (L.). Literature records on Atta and Acromyrmex nest density in the Neotropics were analyzed and A. sexdens demographical aspects were studied in six transects located along the Colombian Amazon River. Literature research results did not show that Atta and Acromyrmex nest densities are consistently higher in disturbed habitats. In transects, 56 active and 182 inactive nests were found in 2008. Higher active nest numbers and densities were determined for 1992, 1999, and 2006. Nests were present in old forest, in agricultural plot and grassland secondary forest, and absent from open spaces around houses, grasslands, agricultural plots, and a particular sector of old forest. Nest densities were higher in secondary forest. Between 1992 and 2008, the size of disturbed areas increased, whereas nest numbers and densities diminished. Average nest age was higher in secondary forest, but maximum nest age was comparable in the three habitats. On average, nests were superficially larger in old forest. Nests were mostly established in old forest, at sites without fallen trees. Almost all of those currently present in secondary forest were established in old forest before any disturbance occurred. In disturbed habitats, nest inactivity was slightly higher and possibly affected by human control efforts. This study suggested that the palatable forage hypothesis alone did not explain observed demographic patterns. Soil physiochemical variables or microclimatic conditions also are thought to play important roles in determining A. sexdens demography. PMID:22251676

  10. Fungos Filamentosos Associados às Espécies Atta sexdens (Linnaeus) e Atta laevigata (F. Smith) (Hymenoptera: Formicidae)

    OpenAIRE

    Aline Dornelas; Renato Sarmento; Gil dos Santos; Mariela Nascimento; Danival de Souza

    2016-01-01

    Resumo. As formigas-cortadeiras, Atta e Acromyrmex, são consideradas as principais pragas no sistema agroflorestal da Região Neotropical. Isso porque cortam material vegetal que servirá de alimento ao fungo simbionte que elas cultivam. Diversos fungos, que ocorrem em condições naturais no solo, podem ser encontrados associados às formigas-cortadeiras, muitos deles comprovadamente entomopatogênicos. No entanto, esses agentes não têm sido usados em programa de controle biológico des...

  11. Los factores ambientales en relación con la hormiga arriera (Atta sexdens) en el sur del trapecio amazónico, Colombia / The environmental factors related to the leafcutter ant (Atta sexdens) in the south of the Amazon trapezium, Colombia

    OpenAIRE

    Van Gils, Heike Antonia Johanna Anna

    2011-01-01

    La hormiga arriera (Atta y Acromyrmex spp.) juega un papel ecológico importante en la zona neotropical como herbívoro dominante e ingeniero de ecosistemas. Sin embargo, aún poco se entienden los mecanismos fundamentales que determinan la distribución y la densidad de los nidos. Este estudio tuvo como objetivo conocer algunos aspectos demograficos de Atta sexdens en la orilla colombiana del río Amazonas y comprobar que, aparte de la vegetación, existen otros factores ambientales que también lo...

  12. Comparative morpho-physiology of the metapleural glands of two Atta leaf-cutting ant queens nesting in clayish and organic soils.

    Science.gov (United States)

    Vieira, Alexsandro Santana; Camargo-Mathias, Maria Izabel; Roces, Flavio

    2015-09-01

    Queens of leaf-cutting ants found their nests singly, each consisting of a vertical tunnel and a final horizontal chamber. Because of the claustral mode of nest founding, the queen and/or her initial fungus garden are exposed to threats imposed by several soil pathogens, and the antibiotic secretions produced by their metapleural glands are considered a main adaptation to deal with them. Nests of two Atta leaf-cutting ant species, Atta vollenweideri and Atta sexdens rubropilosa, occur in different soil types, alfisols and oxisols. Their queens are known to excavate the initial nest in different soil horizons, clayish and organic, respectively, which differ in their fertility and associated microbiota. The aim of the present study was to comparatively investigate the morpho-physiology of the metapleural glands in queens of A. vollenweideri and A. sexdens rubropilosa, addressing the question whether the distinct selective pressure imposed by the microbiota in the two different soil types led to morpho-physiological differences in the metapleural glands that were consistent with their antiseptic function. The results revealed that metapleural glands of A. sexdens rubropilosa have a larger number of secretory cells, and consequently a higher production of antibiotic secretions, which may have been selected to allow nest founding at the superficial horizon of oxisols rich in organic matter and microorganisms. Glands of A. vollenweideri, on the contrary, presented fewer secretory cells, suggesting less production of antibiotic secretions. We argue that the excavation of deep founding nests in A. vollenweideri was primarily selected for during evolution to avoid the risk posed by flooding, and further hypothesize that a reduced number of cells in their metapleural glands occurred because of a weak pathogen-driven selective pressure at the preferred soil depth. PMID:26145506

  13. Lipid and energy contents in the bodies of queens of Atta sexdens rubropilosa Forel (Hymenoptera, Formicidae): pre-and post-nuptial flight

    OpenAIRE

    Ricardo Toshio Fujihara; Roberto da Silva Camargo; Luiz Carlos Forti

    2012-01-01

    The nuptial flight allows males and females to meet and copulate and both need energy to perform this activity. Before leaving the nest, males and females are well nourished and ready to mate. However, little is known about the lipid and energy contents in females before the nuptial flight (virgins) and after it (mated females). In this work we measured lipid concentrations in relation to body weight in these individuals. Our results showed that 16.82% of the bodies of young virgin females on...

  14. Dealing with water deficit in Atta ant colonies: large ants scout for water while small ants transport it

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Da-Silva

    2012-07-01

    Leafcutter ants (Atta sexdens rubropilosa (Forel 1908 have an elaborate social organization, complete with caste divisions. Activities carried out by specialist groups contribute to the overall success and survival of the colony when it is confronted with environmental challenges such as dehydration. Ants detect variations in humidity inside the nest and react by activating several types of behavior that enhance water uptake and decrease water loss, but it is not clear whether or not a single caste collects water regardless of the cost of bringing this resource back to the colony. Accordingly, we investigated water collection activities in three colonies of Atta sexdens rubropilosa experimentally exposed to water stress. Specifically, we analyzed whether or not the same ant caste foraged for water, regardless of the absolute energetic cost (distance of transporting this resource back to the colony. Our experimental design offered water sources at 0 m, 1 m and 10 m from the nest. We studied the body size of ants near the water sources from the initial offer of water (time  =  0 to 120 min, and tested for specialization. We observed a reduction in the average size and variance of ants that corroborated the specialization hypothesis. Although the temporal course of specialization changed with distance, the final outcome was similar among distances. Thus, we conclude that, for this species, a specialist (our use of the word “specialist” does not mean exclusive task force is responsible for collecting water, regardless of the cost of transporting water back to the colony.

  15. Are workers of Atta leafcutter ants capable of reproduction?

    DEFF Research Database (Denmark)

    Dijkstra, Michiel Bendert; Boomsma, Jacobus Jan

    2006-01-01

    ovaries. Workers of Atta leafcutter ants only lay trophic eggs in queenright colonies. Although Atta colonies are commonly kept at universities, museums, and zoos, no reports of worker sons in orphaned colonies exist, suggesting that Atta workers are infertile. To explicitly test this, we created eleven...... orphaned laboratory nests of Atta cephalotes, A. sexdens, and A. colombica, and maintained them for 3-6 months after queen loss. Eight colonies did not produce any brood, but three nests produced 1-4 worker-derived male larvae and pupae. Microsatellite genotyping indicated that these were worker sons...... fertility is low compared to the sister genus Acromyrmex, where workers routinely produce normally-size males after queen loss in the laboratory. We hypothesize that worker reproduction in orphaned Atta field colonies is almost never successful because the last workers die before their sons can be raised to...

  16. Does Diatomaceous Earth Control Leaf-Cutter Ants (Hymenoptera: Formicidae) in the Eucalyptus Plantations?

    Science.gov (United States)

    Ferreira-Filho, Pedro J; Wilcken, Carlos F; Neves, Daniela A; Pogetto, Mario H F A D; Carmo, Janaina B; Guerreiro, Julio C; Serrão, José E; Zanuncio, José C

    2015-06-01

    Genus Atta includes some of the most important Formicidae leaf cutter ants which cause extensive damage to the eucalyptus plantations. Atta sexdens rubropilosa Forel, one of the chief pests in Brazilian reforestation, can restrict and reduce forest productivity by its intense and constant leaf-cutting activities on plants at all stages. Therefore, the demand for new products to control A. sexdens rubropilosa indicates the study of the utilization of the dry powder formulation of diatomaceous earth (DE) against this pest in the eucalyptus cultivars. The study was conducted using 120 colonies of A. sexdens rubropilosa in Eucalyptus grandis Hill ex. Maiden x Eucalyptus urophylla Blake (Myrtaceae) (urograndis) stand. The randomized block experimental design was used with six treatments (1, 10, 25, and 50 g/m2 of DE, 6.0 g/m2 sulfluramid bait per square meter of loose soil, and the control) with five replications, each with four colonies of this ant. Diatomaceous earth was applied to the active A. sexdens rubropilosa ant holes, and the sulfluramid bait was applied in bulk in a localized manner. The control efficacy of A. sexdens rubropilosa with DE was low, showing values similar to that of the control, and, for this reason, it cannot be used to control this ant. The bait with sulfluramid showed higher efficacy than those of the other treatments. PMID:26470237

  17. Cassava leaf methanolic extract as an alternative to control of fall armyworm and leaf cutter ants

    OpenAIRE

    Mírian Aparecida Isidro Santos; Angelita Duarte Corrêa; Ana Paula de Carvalho Alves; Anderson Assaid Simão; Dejane Santos Alves; Rodrigo Lopes de Oliveira; Adelir Aparecida Saczk; Geraldo Andrade Carvalho

    2013-01-01

    The objective of this study was to characterize phenolic compounds and evaluate the effect, under laboratory conditions, of the cassava leaf powder methanol extract on the development of fall armyworm Spodoptera frugiperda and of leaf-cutting ant Atta sexdens rubropilosa. The extract was incorporated into an artificial diet, to which the armyworm was exposed, at concentrations of 250, 500, 1,000 and 1,500 mg kg-1, in order to evaluate biological characteristics. Soon after the insects emergen...

  18. Limonoids from andiroba oil and Cedrela fissilis and their insecticidal activity

    Energy Technology Data Exchange (ETDEWEB)

    Ambrozin, Alessandra R.P.; Leite, Ana C.; Vieira, Paulo C.; Fernandes, Joao B.; Silva, M. Fatima das G. Fernandes da [Sao Carlos Univ., SP (Brazil). Dept. de Quimica]. E-mail: paulo@dq.ufscar.br; Bueno, Fabiana C.; Bueno, Odair C.; Pagnocca, Fernando C.; Hebling, Jose A.; Bacci Junior, Mauricio [UNESP, Rio Claro, SP (Brazil). Centro de Estudos de Insetos Sociais

    2006-05-15

    Nine limonoids were isolated from Carapa guianensis and Cedrela fissilis. Among them, 1,2-dihydro-3{beta}-hydroxy-7-deacetoxy-7-oxogedunin is a new compound. Moreover, the assignments of some chemical shifts of xyloccensin k have been corrected and {sup 1}H NMR data of 7-deacetylgedunin have been assigned for the first time. These isolated limonoids were assayed on Atta sexdens rubropilosa workers showing moderate insecticidal activities. (author)

  19. Limonoids from andiroba oil and Cedrela fissilis and their insecticidal activity

    International Nuclear Information System (INIS)

    Nine limonoids were isolated from Carapa guianensis and Cedrela fissilis. Among them, 1,2-dihydro-3β-hydroxy-7-deacetoxy-7-oxogedunin is a new compound. Moreover, the assignments of some chemical shifts of xyloccensin k have been corrected and 1H NMR data of 7-deacetylgedunin have been assigned for the first time. These isolated limonoids were assayed on Atta sexdens rubropilosa workers showing moderate insecticidal activities. (author)

  20. Professor Atta invited to attend WSIS as `eminent scientist'

    CERN Multimedia

    2003-01-01

    Ministry of Science and Technology Prof. Atta-ur-Rahman has been nominated as an "eminent scientist" to attend the roundtables during "World Summit on the Information Society (WSIS)" on December 12 (1 paragraph).

  1. Activities of extracts and compounds from Spiranthera odoratissima St. Hil. (Rutaceae) in leaf-cutting ants and their symbiotic fungus

    International Nuclear Information System (INIS)

    The study of the Spiranthera odoratissima St. Hil (Rutaceae) branches extracts led to the isolation of the furoquinoline (dictamine, γ-fagarine and skimmianine) and 2-arylquinoli-4-one (1-methyl-2-phenylquinoline-4-one) alkaloids and limonoids (limonexic acid and limonin). The compounds 1-methyl-2-phenylquinoline-4-one and limonexic acid were isolated for the first time from the Spiranthera. These furoquinoline and 2-arylquinoli-4-one alkaloids and limonoids showed insecticidal and/or fungicidal activity in the nest of the Atta sexdens rubropilosa. (author)

  2. Activities of extracts and compounds from Spiranthera odoratissima St. Hil. (Rutaceae) in leaf-cutting ants and their symbiotic fungus

    Energy Technology Data Exchange (ETDEWEB)

    Terezan, Ana Paula; Fernandes, Joao B.; Silva, M. Fatima das Gracas Fernandes da; Vieira, Paulo C. [Universidade Federal de Sao Carlos (UFSCAR), Sao Carlos, SP (Brazil). Dept. de Quimica; Rossi, Raquel Andrade; Almeida, Roberta N.A.; Freitas, Tais Garcia; Bueno, Odair C.; Pagnocca, Fernando C. [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil). Centro de Estudos de Insetos Sociais; Pirani, Jose R., E-mail: djbf@power.ufscar.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Biociencias. Dept. de Botanica

    2010-07-01

    The study of the Spiranthera odoratissima St. Hil (Rutaceae) branches extracts led to the isolation of the furoquinoline (dictamine, gamma-fagarine and skimmianine) and 2-arylquinoli-4-one (1-methyl-2-phenylquinoline-4-one) alkaloids and limonoids (limonexic acid and limonin). The compounds 1-methyl-2-phenylquinoline-4-one and limonexic acid were isolated for the first time from the Spiranthera. These furoquinoline and 2-arylquinoli-4-one alkaloids and limonoids showed insecticidal and/or fungicidal activity in the nest of the Atta sexdens rubropilosa. (author)

  3. Extrações de óleos de sementes de citros e suas atividades sobre a formiga cortadeira Atta sexdens e seu fungo simbionte

    OpenAIRE

    Fernandes João B.; David Valmir; Facchini Patrícia H.; Silva M. Fátima das G. F. da; Rodrigues Filho Edson; Vieira Paulo C.; Galhiane Mário S.; Pagnocca Fernando C.; Bueno Odair C.; Hebling M. José; Victor Sandra R.; Santos Ana Maria Rodrigues dos

    2002-01-01

    Seeds Citrus oils (C. sinensis, C. limon and C. reticulata) extraction with hexane in a soxhlet apparatus and through supercritical fluid (CO2) were done. Besides triglycerides, the oils obtained with hexane comprised volatile compounds such as terpenes and fatty alcohols, esters, and aldehydes. However, the oils obtained by extraction with supercritical fluid presented only triglycerides. These results indicate that the extraction using supercritical fluid presents better selectivity. The ac...

  4. Cassava leaf methanolic extract as an alternative to control of fall armyworm and leaf cutter ants

    Directory of Open Access Journals (Sweden)

    Mírian Aparecida Isidro Santos

    2013-12-01

    Full Text Available The objective of this study was to characterize phenolic compounds and evaluate the effect, under laboratory conditions, of the cassava leaf powder methanol extract on the development of fall armyworm Spodoptera frugiperda and of leaf-cutting ant Atta sexdens rubropilosa. The extract was incorporated into an artificial diet, to which the armyworm was exposed, at concentrations of 250, 500, 1,000 and 1,500 mg kg-1, in order to evaluate biological characteristics. Soon after the insects emergence, another experiment was conducted to verify the possible sub lethal activity of the extract; therefore, S. frugiperda couples were isolated in cages and eggs were collected and counted. The Manihot esculenta Crantz extract caused a reduction in the percentage of armyworm survival, as well as in the eggs number. Then, the same extract was solubilized in 10% ethanol and applied to ants; mortality was observed, compared to the control. It is possible to conclude that the M. esculenta Crantz leaf powder methanolic extract, containing gallic acid and catechin, is a promising alternative to control S. frugiperda and Atta sexdens rubropilosa.

  5. Extrações de óleos de sementes de citros e suas atividades sobre a formiga cortadeira Atta sexdens e seu fungo simbionte Citrus seed oils extractions and their activity against leaf cutting ant Atta sexdens and its symbiotic fungus

    Directory of Open Access Journals (Sweden)

    João B. Fernandes

    2002-12-01

    Full Text Available Seeds Citrus oils (C. sinensis, C. limon and C. reticulata extraction with hexane in a soxhlet apparatus and through supercritical fluid (CO2 were done. Besides triglycerides, the oils obtained with hexane comprised volatile compounds such as terpenes and fatty alcohols, esters, and aldehydes. However, the oils obtained by extraction with supercritical fluid presented only triglycerides. These results indicate that the extraction using supercritical fluid presents better selectivity. The activity of the oils on the development of the ant symbiotic fungus, Leucoagaricus gongylophorus, showed week activity and the topic insecticide assay showed better activity for the tangerine seed oil.

  6. Extrações de óleos de sementes de citros e suas atividades sobre a formiga cortadeira Atta sexdens e seu fungo simbionte Citrus seed oils extractions and their activity against leaf cutting ant Atta sexdens and its symbiotic fungus

    OpenAIRE

    João B Fernandes; Valmir David; Patrícia H. Facchini; M. Fátima das G. F. da Silva; Edson Rodrigues Filho; Paulo C. Vieira; Mário S. Galhiane; Pagnocca, Fernando C.; Odair C. Bueno; M. José Hebling; Sandra R. Victor; Ana Maria Rodrigues dos Santos

    2002-01-01

    Seeds Citrus oils (C. sinensis, C. limon and C. reticulata) extraction with hexane in a soxhlet apparatus and through supercritical fluid (CO2) were done. Besides triglycerides, the oils obtained with hexane comprised volatile compounds such as terpenes and fatty alcohols, esters, and aldehydes. However, the oils obtained by extraction with supercritical fluid presented only triglycerides. These results indicate that the extraction using supercritical fluid presents better selectivity. The ac...

  7. Leaf-cutting ants toxicity of limonexic acid and degraded limonoids from Raulinoa echinata: X-ray structure of epoxy-fraxinellone

    International Nuclear Information System (INIS)

    Phytochemical survey of roots extracts of the South Brazilian endemic plant Raulinoa echinata Cowan, Rutaceae led to the isolation of known degraded limonoids: fraxinellone, fraxinellonone and epoxy-fraxinellone. The latter was previously isolated also from the stems, but the relative configuration could not be solved by NMR experiments. This paper deals with the X-ray diffraction analysis of epoxy-fraxinellone and its toxicity to leaf-cutting ants, describes the isolation of fraxinellonone and fraxinellone for the first time in Raulinoa. Epoxy-fraxinellone showed no toxicity to the leaf-cutting ants (Atta sexdens rubropilosa). The limonoid limonexic acid, isolated from stems, presented high toxicity to the leaf-cutting ants, diminishing considerably their longevity. (author)

  8. Leaf-cutting ants toxicity of limonexic acid and degraded limonoids from Raulinoa echinata: X-ray structure of epoxy-fraxinellone

    Energy Technology Data Exchange (ETDEWEB)

    Biavatti, Maique W.; Westerlon, Rosangela [Universidade do Vale do Itajai, SC (Brazil). Programa de Pos-Graduacao em Ciencias Farmaceuticas]. E-mail: maique@univali.br; Vieira, Paulo C.; Silva, M. Fatima G.F. da; Fernandes, Joao B. [Sao Carlos Univ., SP (Brazil). Dept. de Quimica; Penaflor, M. Fernanda G.V.; Bueno, Odair C. [UNESP, Rio Claro, SP (Brazil). Centro de Estudos de Insetos Sociais; Ellena, Javier [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica

    2005-11-15

    Phytochemical survey of roots extracts of the South Brazilian endemic plant Raulinoa echinata Cowan, Rutaceae led to the isolation of known degraded limonoids: fraxinellone, fraxinellonone and epoxy-fraxinellone. The latter was previously isolated also from the stems, but the relative configuration could not be solved by NMR experiments. This paper deals with the X-ray diffraction analysis of epoxy-fraxinellone and its toxicity to leaf-cutting ants, describes the isolation of fraxinellonone and fraxinellone for the first time in Raulinoa. Epoxy-fraxinellone showed no toxicity to the leaf-cutting ants (Atta sexdens rubropilosa). The limonoid limonexic acid, isolated from stems, presented high toxicity to the leaf-cutting ants, diminishing considerably their longevity. (author)

  9. Attractiveness of copperleaf-based bait to leaf-cutting ants Atratividade de iscas à base de acalifa para formigas cortadeiras

    Directory of Open Access Journals (Sweden)

    Nilson Satoru Nagamoto

    2011-06-01

    Full Text Available Leaves of copperleaf (Acalypha spp. are greatly accepted by leaf-cutting ants and therefore used to maintain colonies in the laboratory. In order to determine the attractive potential of granulated bait of Acalypha wilkesiana leaves versus citrus pulp, currently used in commercial baits, an evaluation was performed, by using the leaf-cutting ant Atta sexdens rubropilosa as model. The handmade non-toxic baits contained powder (90% w/w of either citrus pulp or A. wilkesiana were offered simultaneously in the foraging arena until the total loading of one of them. Results showed that copperleaf baits are less attractive than the citrus ones, which invalidates the viability of the substitution.Folhas de acalifa (Acalypha spp. são de grande aceitação pelas formigas cortadeiras e, por isso, utilizadas na manutenção de colônias em laboratório. Baseado nesses fatos, procedeu-se a uma avaliação da atratividade de isca granulada feita com folhas de Acalypha wilkesiana, usando a formiga cortadeira Atta sexdens rubropilosa como modelo, com o objetivo de determinar o seu potencial atrativo frente ao citros, atualmente utilizado na formulação comercial de iscas formicidas. Foram formuladas artesanalmente iscas atóxicas, contendo pó (90% p/p de polpa cítrica ou de A. wilkesiana. As iscas foram colocadas simultaneamente em uma arena de forrageamento até o carregamento total de uma delas. Os resultados mostram que a isca de acalifa é menos atrativa que a de citros, o que inviabiliza a substituição.

  10. Technical Manual for Attitudes Towards Teaching All Students (ATTAS-mm) Instrument

    Science.gov (United States)

    Gregory, Jess L.; Noto, Lori A.

    2012-01-01

    The general education teacher has the greatest influence on a student's success in school, and a teacher's attitude towards inclusion is a major factor in determining whether inclusion will be successful. The ATTAS-mm is a 9-item scale with strong reliability and validity. The three subscales: believing all students can succeed in general…

  11. Influências de Atta spp. (Hymenoptera: Formicidae na recuperação da vegetação pós-fogo em floresta de transição amazônica Influences of leafcutter ant Atta spp. (Hymenoptera: Formicidae on vegetation recovery after fire in Amazonian transitional forest

    Directory of Open Access Journals (Sweden)

    Karine Santana Carvalho

    2012-03-01

    Full Text Available Este estudo investigou o papel das saúvas na recuperação da vegetação pós-fogo. Foi hipotetizado que a perturbação do fogo aumenta a abundância de ninhos de saúva (1 e as atividades de remoção de sementes (2 e desfolha (3, especialmente no ambiente de borda. Os ninhos de saúva foram inventariados e mapeados e após 17 meses, checados para o registro de sua atividade e de novas colônias emergindo na área. Realizou-se experimentos comparativos de remoção de sementes e desfolha de plântulas em duas parcelas de 50 ha, uma submetida a fogo anual (tratamento e outra sem fogo (controle. A abundância de ninhos de saúva foi maior na parcela tratamento que na parcela controle, especialmente na borda da floresta. As espécies encontradas foram: Atta cephalotes, A. laevigata e A. sexdens , sendo esta última a espécie mais abundante e que mostrou aumento em número de colônias ativas após 17 meses. O aumento na abundância de ninhos na parcela tratamento foi acompanhado por um aumento na atividade dessas formigas. Enquanto mais de duas folhas foram arrancadas por plântula nessa parcela, menos de uma foi registrada na parcela controle. Também a abundância média de galhos desfolhados e de sementes removidas por saúvas foi maior na parcela tratamento que na parcela controle. As saúvas tanto podem diminuir ou retardar o processo de regeneração florestal pós-fogo, quanto acelerá-lo, devido à elevada predação seletiva que favorece as espécies menos palatáveis. Desta forma, suas atividades podem modificador apenas a composição da vegetação recuperando-se do fogo.In this study we investigated the role of leaf-cutting ants in the post-fire vegetation recovery. We hypothesized that a forest plot submitted to annual fire presents: (1 higher abundance of leaf-cutting ant nests; (2 higher removal of seeds; and (3 higher herbivory rates of leaf-cutting ants, when compared to the forest plots without fire (control. The leaf

  12. Mating biology of the leaf-cutting ants Atta colombica and A. cephalotes

    DEFF Research Database (Denmark)

    Baer, Boris; Boomsma, Jacobus J

    2006-01-01

    Copulation behavior has often been shaped by sexually selected sperm competition or cryptic female choice. However, manipulation of previously deposited ejaculates is unknown in the social Hymenoptera and the degree to which sperm competes after insemination or is actively selected by females has...... remained ambiguous. We studied the mating process in the leaf-cutting ants Atta colombica and A. cephalotes, which belong to one of the few derived social insect lineages where obligate multiple mating has evolved. As copulations often occur at night and in remote places, direct observations were...... impossible, so we had to reconstruct the sequential copulation events by morphological analysis of the male and female genitalia and by tracking the process of sperm transfer and sperm storage. We show that Atta male genitalia have two external rows of spiny teeth, which fit into a specialized pouch organ in...

  13. Effect of Tithonia diversifolia Mulch on Atta cephalotes (Hymenoptera: Formicidae) Nests

    OpenAIRE

    Rodríguez, Jonathan; Montoya-Lerma, James; Calle, Zoraida

    2015-01-01

    Recent studies have shown an insecticidal effect of Tithonia diversifolia (Hemsl.) Gray (Asterales: Asteraceae) foliage on workers of Atta cephalotes L. and inhibitory effects of this plant on the growth of the symbiotic fungus Leucoagaricus gongylophorus (A. Müler) Singer. To evaluate the potential of T. diversifolia as a biological control treatment of this important pest, we assessed the effect of green manure (mulch) of this plant on natural nests of A. cephalotes, in Cali, Colombia. Thre...

  14. Hormigas zompopas (Atta cephalotes) influyen positivamente en la biodiversidad vegetal de bosques húmedos tropicales

    OpenAIRE

    Javier Ruiz

    2010-01-01

    REALIZAMOS OBSERVACIONES DE LA HISTORIA NATURAL DE LA HORMIGA ZOMPOPA (Atta cephalotes) en el período de 1995 a 2010. Monitoreamos una población de hormigas zompopas en 2003 y realizamos experimentos de campo en 2006 en el bosque húmedo tropical de la Estación Biológica La Unión en Nicaragua. Los nidos de hormiga zompopa fueron mapeados dentro de una parcela permanente de 6.5 hectáreas. Se estimó lacomposición de especies vegetales en el área del nido de la hormiga, y se realizó un conteo de ...

  15. Self-restraint and sterility in workers of Acromyrmex and Atta leafcutter ants

    DEFF Research Database (Denmark)

    Dijkstra, Michiel Bendert; Nash, David Richard; Boomsma, Jacobus Jan

    2005-01-01

    large workers) lay eggs that are similar in size to queen-laid eggs, but mostly with a reduced amount of yolk. Trophic eggs appear to be an important source of food for larvae in Acromyrmex (especially in Ac. echinatior), but not in Atta. Five (0.8) of 616 dissected Ac. echinatior workers but no Ac...

  16. Avaliação de sauveiros externos em eucaliptais de Minas Gerais

    Directory of Open Access Journals (Sweden)

    Iris Cristiane Magistrali

    2011-06-01

    Full Text Available Existe uma grande dificuldade em aperfeiçoar as técnicas de manejo de formigas cortadeiras, sobretudo no que diz respeito aos sauveiros externos localizados próximos a plantios florestais. Por causa disso, o presente trabalho teve por objetivo caracterizar aspectos como tamanho e distância de sauveiros externos em plantações de eucaliptos. A avaliação foi realizada em aceiros externos de três fazendas localizadas nos municípios de João Pinheiro e Buritizeiro, em Minas Gerais, seis meses após ser realizado o combate convencional às formigas cortadeiras. Foram encontrados nove sauveiros externos, com área média de terra solta de 62,5 ± 11,1 m2, localizados a uma distância média de 33,94 ± 8,68 metros entre a margem do plantio e o local do formigueiro. Constatou-se que tais características podem ser úteis no ajuste da largura da faixa de segurança de combate, a qual deve ser igual a 50 m. O gênero Trachymyrmex e as espécies Atta laevigata e Atta sexdens rubropilosa foram registrados como ocorrências novas no município de Buritizeiro, e o gênero Acromyrmex como uma nova ocorrência nos dois municípios.

  17. Parasitoids of the endangered leafcutter ant Atta robusta Borgmeier in urban and natural areas

    Directory of Open Access Journals (Sweden)

    Diego S. Gomes

    2013-09-01

    Full Text Available Parasitoids of the endangered leafcutter ant Atta robusta Borgmeier in urban and natural areas. Hosts of parasitoids in urban areas may suffer from a double threat of habitat destruction by urbanization and parasitism pressure. Moreover, the parasitoids themselves might be at risk if they are specialists. Here, we studied whether Atta robusta (Hymenoptera, Formicidae, which is on the red list of Brazilian threatened species, suffers from higher parasitism pressure in an urban area compared to a natural one. In addition, we determined whether their specialist parasitoids, Eibesfeldtphora breviloba and Myrmosicarius exrobusta (Diptera, Phoridae, are in risk and evaluated whether they are influenced by habitat structure, temperature, humidity, ant traffic, and time of the day. The study was carried out in an urban park and in a natural protected area in the city of Rio de Janeiro. In each site we chose an open area and a closed area (forest and sampled nine nests in each area. We found that parasitism pressure was similar in urban and natural areas, with the same two parasitoid species present in both areas. The main difference was related to habitat structure, since M. exrobusta was mainly present in open areas while E. breviloba was almost exclusively found in closed areas. Myrmosicarius exrobusta was not present during the hottest midday times, and its abundance was negatively correlated to vapor pressure deficit. These results suggest that green areas can be an important component in efforts to conserve diversity in urban areas. However, the complexity of the habitats in those areas is a fundamental issue in designing urban parks.

  18. Internalisasi Konsep Ta’dîb Al-Attas dalam Pengembangan Karakter Peserta Didik

    Directory of Open Access Journals (Sweden)

    M. Arfan Mu’ammar

    2013-11-01

    Full Text Available The ‘character building’ topic starts as the top topics in discussion latterly. Various training holds sporadically for the executives, teachers, and employer’s company in outbound form or workshop. Those activities are good definitely, but it’s not enough to build a character. We have to combine our efforts systematically and integrated, so the character building as we want can be effective, learnable and known by the others. That’s all because the intellectualities and cognitive capability cannot guarantee for someone to be able to erase his mentality of corruption, collusion and nepotism, etc. In the other side, awkward’s morality can override the student’s intellectualities. Al-Attas as a Muslim scholar, offers a concept of Ta’dib that has been offered and nominated in the first time at the First Islamic Conference at Mecca in 1977. Al-Attas has a notion that everyone who learned is good man and the term ‘good’ here is a behavior that includes of someone’s spiritual life and material, who try to implants kindliness that he accepted it. The good man is a human being who has characters and polite. The internalization concept of Ta’dib inside of Character building is a requirement than we need, especially this times that we have to face some thoughtfulness phenomena’s degradation of moral. This Ta’dib concept leads someone to be able to put something in its place. So, we can create some condition which the structuralist’s fungsional called as well regulated society. If this society does not reflects the well regulate society, then this society still uncultured.

  19. Diversity of Fungi Associated with Atta bisphaerica (Hymenoptera: Formicidae: The Activity of Aspergillus ochraceus and Beauveria bassiana

    Directory of Open Access Journals (Sweden)

    Myriam M. R. Ribeiro

    2012-01-01

    Full Text Available The grass-cutting ant Atta bisphaerica is one of the most serious pests in several pastures and crops in Brazil. Fungal diseases are a constant threat to these large societies composed of millions of closely related individuals. We investigated the occurrence of filamentous fungi associated with the ant A. bisphaerica in a pasture area of Viçosa, Minas Gerais State, Brazil. Several fungi species were isolated from forager ants, and two of them, known as entomopathogenic, Beauveria bassiana and Aspergillus ochraceus, were tested against worker ants in the laboratory. The two species were highly virulent, achieving 50 percent worker mortality within 4-5 days. It is the first time A. ochraceus, a commonly found fungal species, is reported to infect Atta species at a high prevalence. Possible uses for the fungus within biological control are discussed.

  20. Diversity of Fungi Associated with Atta bisphaerica (Hymenoptera: Formicidae): The Activity of Aspergillus ochraceus and Beauveria bassiana

    OpenAIRE

    Ribeiro, Myriam M. R.; Karina D. Amaral; Vanessa E. Seide; Souza, Bressane M. R.; Della Lucia, Terezinha M. C.; Maria Catarina M. Kasuya; Danival J. de Souza

    2012-01-01

    The grass-cutting ant Atta bisphaerica is one of the most serious pests in several pastures and crops in Brazil. Fungal diseases are a constant threat to these large societies composed of millions of closely related individuals. We investigated the occurrence of filamentous fungi associated with the ant A. bisphaerica in a pasture area of Viçosa, Minas Gerais State, Brazil. Several fungi species were isolated from forager ants, and two of them, known as entomopathogenic, Beauveria bassiana an...

  1. Hormigas zompopas (Atta cephalotes influyen positivamente en la biodiversidad vegetal de bosques húmedos tropicales

    Directory of Open Access Journals (Sweden)

    Javier Ruiz

    2010-08-01

    Full Text Available REALIZAMOS OBSERVACIONES DE LA HISTORIA NATURAL DE LA HORMIGA ZOMPOPA (Atta cephalotes en el período de 1995 a 2010. Monitoreamos una población de hormigas zompopas en 2003 y realizamos experimentos de campo en 2006 en el bosque húmedo tropical de la Estación Biológica La Unión en Nicaragua. Los nidos de hormiga zompopa fueron mapeados dentro de una parcela permanente de 6.5 hectáreas. Se estimó lacomposición de especies vegetales en el área del nido de la hormiga, y se realizó un conteo de plántulas dicotiledóneas y plántulas de palmas (monocotiledóneas. Los resultados indican que las hormigas zompopas prefieren defoliar plántulas de especies dicotiledóneas,favoreciendo la regeneración de palmas sobre el nido de las hormigas. Las zompopas favorecen la regeneración de palmas en áreas donde ellas establecen el montículo principal de sus nidos. En el artículo se discuten las implicaciones de estos resultados para la dinámicade la regeneración en bosques húmedos tropicales.

  2. Effect of Tithonia diversifolia mulch on Atta cephalotes (Hymenoptera: Formicidae) nests.

    Science.gov (United States)

    Rodríguez, Jonathan; Montoya-Lerma, James; Calle, Zoraida

    2015-01-01

    Recent studies have shown an insecticidal effect of Tithonia diversifolia (Hemsl.) Gray (Asterales: Asteraceae) foliage on workers of Atta cephalotes L. and inhibitory effects of this plant on the growth of the symbiotic fungus Leucoagaricus gongylophorus (A. Müler) Singer. To evaluate the potential of T. diversifolia as a biological control treatment of this important pest, we assessed the effect of green manure (mulch) of this plant on natural nests of A. cephalotes, in Cali, Colombia. Three treatments were randomly assigned to 30 nests: 1) green mulch of T. diversifolia, 2) green mulch of Miconia sp., Ruiz & Pav. and 3) unmulched control. Every 2 wk for 6 mo, the surface of the nests was completely covered with leaves. Physical and chemical parameters of nest soil were assessed before the first and after the last application of the mulch. Ant foraging in T. diversifolia-treated nests decreased by 60% after the initial applications of the mulch, while nest surface area decreased by 40%. When the nests covered with T. diversifolia were opened, it was observed that the superficial fungus chambers had been relocated at a greater depth. In addition, microbial activity and soil pH increased by 84% and 12%, respectively, in nests covered with plant residues. In conclusion, the continued use of T. diversifolia mulch reduces foraging activity and negatively affects the internal conditions of the colonies, thereby inducing the ants to relocate the fungus chambers within the nests. PMID:25843585

  3. Stress induced ordering due interstitials in Nb-4.7 at.%Ta

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, L.H. de [USP, Instituto de Fisica de Sao Carlos, 13560-970 Sao Carlos, SP (Brazil); UNESP, Grupo de Relaxacoes Anelasticas, 17033-360 Bauru, SP (Brazil); Grandini, C.R. [UNESP, Grupo de Relaxacoes Anelasticas, 17033-360 Bauru, SP (Brazil)]. E-mail: betog@fc.unesp.br; Machado, J.P.B. [FAENQUIL, Departamento de Engenharia de Materiais, 12600-000 Lorena, SP (Brazil); Rodrigues, D. [FAENQUIL, Departamento de Engenharia de Materiais, 12600-000 Lorena, SP (Brazil)

    2005-12-05

    The presence of interstitial elements in metals cause strong changes in their physical, chemical or mechanical properties. These interstitial impurities interact with the metallic matrix atoms by a relaxation process known as stress induced ordering. Relaxation processes give rise to a peak in the internal friction spectrum, known as Snoek effect. The presence of substitutional solutes has a strong influence on Snoek effect, particularly if the substitutional solute element is the one, which interacts with the interstitial element. Anelastic spectroscopy measurements provide information of the behavior of these impurities in the metallic matrix. In this paper, polycrystalline samples of Nb-4.7 at.%Ta alloy have been analyzed in the as-received condition. Measurements of anelastic spectroscopy were carried out using an inverted torsion pendulum, operating with frequency of 2.0-30.0 Hz and in a temperature range between 300 and 700 K. It was observed the presence of a relaxation structure that have been attributed to stress induced ordering due to interstitial atoms around atoms of the metallic matrix. The relaxation structure have been decomposed in its constituent peaks, what it allowed to identify the following relaxation processes: Ta-O, Nb-O and Nb-N.

  4. Stress induced ordering due interstitials in Nb-4.7 at.%Ta

    International Nuclear Information System (INIS)

    The presence of interstitial elements in metals cause strong changes in their physical, chemical or mechanical properties. These interstitial impurities interact with the metallic matrix atoms by a relaxation process known as stress induced ordering. Relaxation processes give rise to a peak in the internal friction spectrum, known as Snoek effect. The presence of substitutional solutes has a strong influence on Snoek effect, particularly if the substitutional solute element is the one, which interacts with the interstitial element. Anelastic spectroscopy measurements provide information of the behavior of these impurities in the metallic matrix. In this paper, polycrystalline samples of Nb-4.7 at.%Ta alloy have been analyzed in the as-received condition. Measurements of anelastic spectroscopy were carried out using an inverted torsion pendulum, operating with frequency of 2.0-30.0 Hz and in a temperature range between 300 and 700 K. It was observed the presence of a relaxation structure that have been attributed to stress induced ordering due to interstitial atoms around atoms of the metallic matrix. The relaxation structure have been decomposed in its constituent peaks, what it allowed to identify the following relaxation processes: Ta-O, Nb-O and Nb-N

  5. Expressed sequence tags from Atta laevigata and identification of candidate genes for the control of pest leaf-cutting ants

    Directory of Open Access Journals (Sweden)

    Henrique-Silva Flávio

    2011-06-01

    Full Text Available Abstract Background Leafcutters are the highest evolved within Neotropical ants in the tribe Attini and model systems for studying caste formation, labor division and symbiosis with microorganisms. Some species of leafcutters are agricultural pests controlled by chemicals which affect other animals and accumulate in the environment. Aiming to provide genetic basis for the study of leafcutters and for the development of more specific and environmentally friendly methods for the control of pest leafcutters, we generated expressed sequence tag data from Atta laevigata, one of the pest ants with broad geographic distribution in South America. Results The analysis of the expressed sequence tags allowed us to characterize 2,006 unique sequences in Atta laevigata. Sixteen of these genes had a high number of transcripts and are likely positively selected for high level of gene expression, being responsible for three basic biological functions: energy conservation through redox reactions in mitochondria; cytoskeleton and muscle structuring; regulation of gene expression and metabolism. Based on leafcutters lifestyle and reports of genes involved in key processes of other social insects, we identified 146 sequences potential targets for controlling pest leafcutters. The targets are responsible for antixenobiosis, development and longevity, immunity, resistance to pathogens, pheromone function, cell signaling, behavior, polysaccharide metabolism and arginine kynase activity. Conclusion The generation and analysis of expressed sequence tags from Atta laevigata have provided important genetic basis for future studies on the biology of leaf-cutting ants and may contribute to the development of a more specific and environmentally friendly method for the control of agricultural pest leafcutters.

  6. Optimal conditions to rear phorid parasitoids (Diptera: Phoridae) of Atta vollenweideri and Acromyrmex lundii (Hymenoptera: Formicidae).

    Science.gov (United States)

    Guillade, Andrea C; Folgarait, Patricia J

    2014-04-01

    Phorid flies have been considered viable options for biological control of leaf-cutter ants because they are highly specific to these hosts, producing direct mortality and also affecting the normal functioning of colonies. Designing protocols for mass rearing of these insects requires knowing the temperature and humidity conditions that optimize their development in terms of duration, survivorship and longevity of adults. We reared Apocephalus setitarsus Brown, Eibesfeldtphora trilobata Disney, and Myrmosicarius brandaoi Disney, which are specific leaf-cutter ant parasitoids of Atta vollenweideri Forel, and Apocephalus neivai Borgmeier and Myrmosicarius catharinensis Borgmeier, which are parasitoids of Acromyrmex lundii Guérin-Méneville. Phorids were maintained under one of five different rearing conditions, 20°C high humidity (20HH), 24°C low and high humidity (24LH and 24HH), and 28°C low and high humidity (28LH and 28HH). Flies from all species could complete their development under all the conditions tested. As expected, the 20HH treatment significantly lengthened all developmental periods in all species, whereas the shortest duration was achieved under 28HH. Although pupal survivorship was highest at 24HH, the greatest longevity of adults was achieved at 20HH. Percentage of pupae obtained and pupal survivorship also exhibited the highest values at 24HH. The rearing efficiency index was highest for all species at 24HH. Therefore, we suggest this temperature and humidity combination as the most suitable for rearing these species, whereas the 20HH treatment is ideal for maintaining adults for longer periods, which would be advantageous for synchronizing matings and mass releases of adults in the field. PMID:24565267

  7. Variation in male body size and reproductive allocation in the leafcutter ant Atta colombica

    DEFF Research Database (Denmark)

    Stürup, M.; den Boer, S. P. A.; Nash, David Richard;

    2011-01-01

    Remarkably little is known about the traits that determine reproductive success of males in eusocial insects. Their window for mate choice decisions is very short, the actual mating process is very difficult to observe, and their small body sizes have likely prevented systematic studies in many...... species. In 2008 and 2009, we revisited a Panamanian population of Atta colombica leafcutter ants to partially repeat and complement a study of more than 15 years ago. We compared within- and between-colony variation in male body size (mass and width of head, mesosoma and gaster) and sperm characteristics...

  8. Eficiência de produtos termonebulígenos no controle de Atta laevigata (Hymenoptera: Formicidae em plantio de eucalipto Efficiency of products for thermonebulization on the control of Atta laevigata (Hymenoptera: Formicidae in eucalypus plantations

    Directory of Open Access Journals (Sweden)

    Ronald Zanetti

    2008-08-01

    Full Text Available Avaliou-se a eficiência de produtos termonebulígenos, a base de clorpirifós ou de extratos vegetais, comparativamente ao uso de isca formicida, a base de sulfluramida, no controle de Atta laevigata (F. Smith, 1858 (Hymenoptera: Formicidae. Foi avaliada a percentagem de paralisação das atividades de corte de folhas e de movimentação de formigas de A. laevigata aos três, 12, 36, 63 e 86 dias após a aplicação dos tratamentos. Na última avaliação, os formigueiros foram abertos para a verificação da eficiência de controle. Todos os produtos testados apresentaram alta percentagem de paralisação das atividades de corte e de movimentação das formigas aos três e 12 dias após a aplicação, respectivamente. Os produtos a base de clorpirifós e um a base de extratos vegetais apresentaram alta eficiência no controle de A. laevigata, sendo mais efetivos que a isca formicida testada.The efficiency of products formulated with chlorpyrifos or plants extracts in thermonebuzation was evaluated and compared to the use of the granulated bait formulated with sulfluramid in the control of Atta laevigata (F. Smith, 1858 (Hymenoptera: Formicidae. The cutting activity and the movement of ants on the colonies were evaluated at three, 12, 36, 63 and 86 days after the application of the treatments. The colonies of these ants were excavated in the last evaluation to obtain the efficiency of each product. All products stopped the cutting activity and movements of the individuals of A. laevigata three and 12 days after their application, respectively. Products formulated with chlorpyrifos and one with plant extracts were more efficient than granulated bait.

  9. Fungus gardens of the leafcutter ant Atta colombica function as egg nurseries for the snake Leptodeira annulata

    DEFF Research Database (Denmark)

    Baer, Boris; Den Boer, Susanne Petronella A; Kronauer, Daniel; Nash, David Richard; Boomsma, Jacobus Jan

    2009-01-01

    Attine ants are well known for their mutualistic symbiosis with fungus gardens, but many other symbionts and commensals have been described. Here, we report the discovery of two clusters of large snake eggs in neighboring fungus gardens of a mature Atta colombica colony. The eggs were completely...... embedded within the fungus garden and were ignored by the host ants, even when we placed them into another, freshly excavated fungus garden of the same colony. All five eggs contained embryos and two snakes eventually hatched, which we identified as being banded cat eyed snakes Leptodeira annulata L. Ant...... fungus gardens are likely to provide ideal climatic conditions for developing snake eggs and almost complete protection from egg predation. Our observations therefore indicate that mature banded cat eyed snakes are able to enter and oviposit in large and well defended Atta colonies without being attacked...

  10. Soil Moisture and Excavation Behaviour in the Chaco Leaf-Cutting Ant (Atta vollenweideri): Digging Performance and Prevention of Water Inflow into the Nest

    OpenAIRE

    Steffen Pielström; Flavio Roces

    2014-01-01

    The Chaco leaf-cutting ant Atta vollenweideri is native to the clay-heavy soils of the Gran Chaco region in South America. Because of seasonal floods, colonies are regularly exposed to varying moisture across the soil profile, a factor that not only strongly influences workers' digging performance during nest building, but also determines the suitability of the soil for the rearing of the colony's symbiotic fungus. In this study, we investigated the effects of varying soil moisture on behavio...

  11. Metarhizium anisopliae and Trichoderma viride control colonies of Atta cephalotes in field better than a chemical insecticide

    Directory of Open Access Journals (Sweden)

    Elkin López Arismendy

    2011-12-01

    Full Text Available The leaf-cutting ant Atta cephalotes is an economically important pest in agriculture. These ants use the material they cut to cultivate a fungus from which they fed. In this study, baits prepared with the entomopathogenic fungus Metarhizium anisopliae strain M-137, Trichoderma viride strain T-26, antagonist of the symbiont fungus of A. cephaloies, and a combination of both fungi were applied in order to control A. cephalotes colonies under field conditions. In addition, the insecticide activity of the baits was compared to a chemical product, Pirimifos Metil, which was applied with an air pump. The ants did not detect the fungal agents contained in the baits, and introduced then into their nests without awakening defensive behaviors. The mortality of the bait-treated nests was higher than 80% while the treatment with Pirimifos Metil was effective in only 60% of the nests. Additionally, a week after the application of these treatments, changes in the insects' behavior were observed, reflected mainly in the absence of foraging activity. In conclusion, M. anisopliae was effective in controlling A. cephalotes colonies, and superior to the chemical product Pirimifos Metil. 

  12. Paleodistributions and comparative molecular phylogeography of leafcutter ants (Atta spp. provide new insight into the origins of Amazonian diversity.

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    Scott E Solomon

    Full Text Available The evolutionary basis for high species diversity in tropical regions of the world remains unresolved. Much research has focused on the biogeography of speciation in the Amazon Basin, which harbors the greatest diversity of terrestrial life. The leading hypotheses on allopatric diversification of Amazonian taxa are the Pleistocene refugia, marine incursion, and riverine barrier hypotheses. Recent advances in the fields of phylogeography and species-distribution modeling permit a modern re-evaluation of these hypotheses. Our approach combines comparative, molecular phylogeographic analyses using mitochondrial DNA sequence data with paleodistribution modeling of species ranges at the last glacial maximum (LGM to test these hypotheses for three co-distributed species of leafcutter ants (Atta spp.. The cumulative results of all tests reject every prediction of the riverine barrier hypothesis, but are unable to reject several predictions of the Pleistocene refugia and marine incursion hypotheses. Coalescent dating analyses suggest that population structure formed recently (Pleistocene-Pliocene, but are unable to reject the possibility that Miocene events may be responsible for structuring populations in two of the three species examined. The available data therefore suggest that either marine incursions in the Miocene or climate changes during the Pleistocene--or both--have shaped the population structure of the three species examined. Our results also reconceptualize the traditional Pleistocene refugia hypothesis, and offer a novel framework for future research into the area.

  13. Controle de Atta laevigata (Hymenoptera: Formicidae com a isca Landrin-F, em área anteriormente coberta com Eucalyptus Control of Atta laevigata (Hymenoptera: Formicidae, with Landrin-F bait, in areas previously covered with Eucalyptus

    Directory of Open Access Journals (Sweden)

    José Cola Zanuncio

    1999-12-01

    Full Text Available Embora muitos produtos tenham sido testados como princípio ativo de iscas formicidas, o mercado predominantemente utilizava produtos à base de dodecacloro. Com a proibição deste último composto, surgiram as iscas à base de sulfluramida ou de clorpirifós, constituindo, atualmente, dois dos princípios ativos de iscas formicidas, disponíveis no mercado. Este trabalho objetivou testar a isca Landrin-F (clorpirifós 0,45% no controle da formiga cortadeira Atta laevigata (F. Smith (Hymenoptera: Formicidae, comparado à isca Mirex-S (sulfluramida 0,3%. Foram utilizados tratamentos com a aplicação de 30 a 120 gramas da isca Landrin-F por olheiro; aplicação de 8g/m² de formigueiro da isca Landrin-F; aplicação de 8 g/m² de formigueiro da isca Mirex-S e; testemunha, sem aplicação de isca formicida. Após 24 e 48 horas, avaliaram-se o transporte e/ou devolução das iscas, e aos 7, 15, 30, 60, 90, 120, 150, 180 e 210 dias, a atividade dos formigueiros, os quais foram sondados e escavados, aos 180 dias, e feita a avaliação final de atividade aos 210 dias. A utilização da metodologia de aplicação da isca Landrin-F por olheiro ativo aumentou consideravelmente a quantidade de isca aplicada, em relação à metodologia de aplicação por metro quadrado de formigueiro. Como a isca Landrin-F mostrou eficiência semelhante nas duas metodologias de aplicação, recomenda-se que a mesma seja aplicada na dosagem de 8g/m² de formigueiro para o controle de A. laevigata.Although many insecticides have been tested as baits against leaf cutting ants, the market was dominated by those with dodecachlor. This compound was banned and the new baits for these pests have either sulfluramid or chlorpirifos. The objective of this work was to test the Landrin-F (chlorpirifos 0.45% bait against the leaf cutting ant Atta laevigata (F. Smith, 1858 (Hymenoptera: Formicidae compared to Mirex-S (sulfluramid 0.3% bait. Treatments used were: application of 30 to

  14. Spatio-Temporal Dynamics of Foraging Networks in the Grass-Cutting Ant Atta bisphaerica Forel, 1908 (Formicidae, Attini).

    Science.gov (United States)

    Lopes, Juliane F S; Brugger, Mariana S; Menezes, Regys B; Camargo, Roberto S; Forti, Luiz Carlos; Fourcassié, Vincent

    2016-01-01

    Foraging networks are a key element for ant colonies because they facilitate the flow of resources from the environment to the nest and they allow the sharing of information among individuals. Here we report the results of an 8-month survey, extending from November 2009 to June 2010, of the foraging networks of four mature colonies of Atta bisphaerica, a species of grass-cutting ant which is considered as a pest in Brazil. We found that the distribution of foraging effort was strongly influenced by the landscape features around the nests, in particular by the permanently wet parts of the pasture in which the nests were located. The foraging networks consisted of underground tunnels which opened on average at 21.5m from the nests and of above-ground physical trails that reached on average 4.70m in length. The use of the foraging networks was highly dynamic, with few sections of the networks used for long periods of time. Three different phases, which could be linked to the seasonal change in the local rainfall regime, could be identified in the construction and use of the foraging networks. The first phase corresponded to the beginning of the rainy season and was characterized by a low foraging activity, as well as a low excavation and physical trail construction effort. The second phase, which began in February and extended up to the end of the humid season at the end of March, was characterized by an intense excavation and trail construction effort, resulting in an expansion of the foraging networks. Finally, in the third phase, which corresponded to the beginning of the dry season, the excavation and trail construction effort leveled off or decreased while foraging activity kept increasing. Our hypothesis is that ants could benefit from the underground tunnels and physical trails built during the humid season to maintain their foraging activity at a high level. PMID:26752413

  15. Spatio-Temporal Dynamics of Foraging Networks in the Grass-Cutting Ant Atta bisphaerica Forel, 1908 (Formicidae, Attini.

    Directory of Open Access Journals (Sweden)

    Juliane F S Lopes

    Full Text Available Foraging networks are a key element for ant colonies because they facilitate the flow of resources from the environment to the nest and they allow the sharing of information among individuals. Here we report the results of an 8-month survey, extending from November 2009 to June 2010, of the foraging networks of four mature colonies of Atta bisphaerica, a species of grass-cutting ant which is considered as a pest in Brazil. We found that the distribution of foraging effort was strongly influenced by the landscape features around the nests, in particular by the permanently wet parts of the pasture in which the nests were located. The foraging networks consisted of underground tunnels which opened on average at 21.5m from the nests and of above-ground physical trails that reached on average 4.70m in length. The use of the foraging networks was highly dynamic, with few sections of the networks used for long periods of time. Three different phases, which could be linked to the seasonal change in the local rainfall regime, could be identified in the construction and use of the foraging networks. The first phase corresponded to the beginning of the rainy season and was characterized by a low foraging activity, as well as a low excavation and physical trail construction effort. The second phase, which began in February and extended up to the end of the humid season at the end of March, was characterized by an intense excavation and trail construction effort, resulting in an expansion of the foraging networks. Finally, in the third phase, which corresponded to the beginning of the dry season, the excavation and trail construction effort leveled off or decreased while foraging activity kept increasing. Our hypothesis is that ants could benefit from the underground tunnels and physical trails built during the humid season to maintain their foraging activity at a high level.

  16. The genome sequence of the leaf-cutter ant Atta cephalotes reveals insights into its obligate symbiotic lifestyle.

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    Garret Suen

    Full Text Available Leaf-cutter ants are one of the most important herbivorous insects in the Neotropics, harvesting vast quantities of fresh leaf material. The ants use leaves to cultivate a fungus that serves as the colony's primary food source. This obligate ant-fungus mutualism is one of the few occurrences of farming by non-humans and likely facilitated the formation of their massive colonies. Mature leaf-cutter ant colonies contain millions of workers ranging in size from small garden tenders to large soldiers, resulting in one of the most complex polymorphic caste systems within ants. To begin uncovering the genomic underpinnings of this system, we sequenced the genome of Atta cephalotes using 454 pyrosequencing. One prediction from this ant's lifestyle is that it has undergone genetic modifications that reflect its obligate dependence on the fungus for nutrients. Analysis of this genome sequence is consistent with this hypothesis, as we find evidence for reductions in genes related to nutrient acquisition. These include extensive reductions in serine proteases (which are likely unnecessary because proteolysis is not a primary mechanism used to process nutrients obtained from the fungus, a loss of genes involved in arginine biosynthesis (suggesting that this amino acid is obtained from the fungus, and the absence of a hexamerin (which sequesters amino acids during larval development in other insects. Following recent reports of genome sequences from other insects that engage in symbioses with beneficial microbes, the A. cephalotes genome provides new insights into the symbiotic lifestyle of this ant and advances our understanding of host-microbe symbioses.

  17. Magnetic anisotropy and organization of nanoparticles in heads and antennae of neotropical leaf-cutter ants, Atta colombica

    International Nuclear Information System (INIS)

    Oriented magnetic nanoparticles have been suggested as a good candidate for a magnetic sensor in ants. Behavioural evidence for a magnetic compass in neotropical leaf-cutter ants, Atta colombica (Formicidae: Attini), motivated a study of the arrangement of magnetic particles in the ants’ four major body parts by measuring the angular dependence of the ferromagnetic resonance spectra at room temperature. Spectra of the thoraces and those of the abdomens showed no significant angular dependence, while those of the antennae and those of the heads exhibited a periodic dependence relative to the magnetic field. Fitting of the angular dependence of the resonant field resulted in an unexpected magnetic anisotropy with uniaxial symmetry. High values of the first order anisotropy constant were observed for the magnetic material in antennae (−2.9  ×  105 erg cm−3) and heads (−1  ×  106 erg cm−3) as compared to body parts of other social insects. In addition, the magnitude of the anisotropy in the heads was comparable to that observed in magnetite nanoparticles of 4–5 nm diameter. For the antennae, the mean angle of the particles’ easy magnetization axis (EA) was estimated to be 41° relative to the straightened antenna’s long axis. For the heads, EA was approximately 60° relative to the head’s axis running from midway between the spines to the clypeus. These physical characteristics indicate organized magnetic nanoparticles with a potential for directional sensitivity, which is an important feature of magnetic compasses. (paper)

  18. Response of the grass-cutting ant Atta capiguara Gonçalves, 1944 (Hymenoptera: Formicidae to sugars and artificial sweeteners

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    Boaretto Maria Aparecida Castellani

    2003-01-01

    Full Text Available Using of toxic baits made of dehydrated citric pulp to control grass-cutting ants can lead to unsatisfactory results because of the low attractiveness of the substrate to worker ants. This work aimed to identify attractive substances, with potential for incorporation in a matrix of granulated baits for grass-cutting ants, among several kinds of sugars and substances used in artificial sweeteners. Experiments were carried out in mature nests of Atta capiguara (Hym.: Formicidae set in pasture. Studied substances were sucrose, fructose, soluble starch, raffinose, maltose, lactose, sorbose, cellobiose, arabinose, xylose, glucose, galactose, rhamnose, arabinose, melezitose, saccharine and cyclamate (at 5.0% w/v. Later, on maltose, xylose, sucrose, fructose and glucose solutions were included at 5.0%, 7.5%, 10.0% and 20.0% w/v, respectively. Cellulose rectangles were used as vehicle and number of rectangles carried into the colonies was evaluated. Carrying rates were very low with maximum means of 9.6% for lactose and 6.0% for arabinose and cyclamate, at the 5.0% concentration. No differences (P > 0.05 were observed relatively to the control (distilled water. No effects were detected for solution, concentration and for the interaction of these factors. Sugars and artificial sweeteners studied were not attractive to Atta capiguara workers, turning their inclusion as attractants in toxic ant baits not viable.

  19. Spatially Heterogeneous Nest-Clearing Behavior Coincides with Rain Event in the Leaf-Cutting Ant Atta cephalotes (L.) (Hymenoptera: Formicidae).

    Science.gov (United States)

    Stephan, J G; Wirth, R; Leal, I R; Meyer, S T

    2015-04-01

    Leaf-cutting ants of the genus Atta construct the probably largest nests among ants and are ecosystem engineers because they alter light and nutrient availability at nest sites. Besides creating canopy gaps in the forest, workers remove all vegetation from atop their nest mounds. Here, we examined the extent and spatial distribution of this nest-clearing behavior by transplanting Licania tomentosa seedlings on Atta cephalotes (Linnaeus) nest mounds in the Atlantic forest in northeast Brazil and documented defoliation patterns by the workers. Within 9 days, workers removed around 53% of the total leaf area planted per colony. All colonies showed a synchronized start of defoliation after a rain event in the fifth night after the seedlings had been transplanted. Defoliation increased with time elapsed since transplanting and with the number of entrances surrounding each seedling. In addition, workers started defoliation on the top of the mound. In contrast, the distance to the next entrance and the size of the seedling did not affect the defoliation pattern. Defoliation was not part of the colony foraging activities but was identified as an element of nest maintenance. Possible cues triggering nest-clearing behavior and the potential link between nest-clearing activities and the control of microclimate of ant nests are discussed. PMID:26013129

  20. Morpho-physiological Differences of the Spermatheca of Attini Ants (Hymenoptera: Myrmicinae

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    Gabriela Ortiz

    2006-01-01

    Full Text Available The insect's spermatheca store the spermatozoa from the time of copulation until the fertilization of the eggs and consists of a sac, usually associated to glands. The ant species Atta laevigata, Atta sexdens sexdens, Atta sexdens piriventris, Acromyrmex coronatus and Cyphomyrmex muelleri are considered pests, as they cause economics losses to several crops. The spermatheca of these species were examined by scanning electron microscopy, histological and histochemical techniques. Their morphology resembled that of a bilobular pouch partially jointed in the central portion. In A. coronatus and C. muelleri it is flatter in shape than those of other species. The external spermathecal gland, groups of secretory cells, was located at the joining point of the two spermathecal lobes of the reservoir. This was observed in A. laevigata, A. s. sexdens and A. coronatus, like a group of cells, while in C. muelleri, like filaments. An external associated gland was not observed in A. s. piriventris, instead secretory cells were arranged in a simple prismatic epithelium internally lining the spermathecal lumen. This epithelium was also observed in A. s. sexdens, although it was restricted to the joining point of the spermathecal lobes. The presence of an internal secretory epithelium in A. s. piriventris and A. s. sexdens suggests that their physiology for the maintenance of spermatozoa in viable conditions for egg fertilization might differ from A. laevigata, A. coronatus and C. muelleri, in which only an external spermathecal gland was observed.

  1. Rapid shifts in Atta cephalotes fungus-garden enzyme activity after a change in fungal substrate (Attini, Formicidae)

    DEFF Research Database (Denmark)

    Kooij, P W; Schiøtt, M; Boomsma, J J;

    2011-01-01

    Fungus gardens of the basidiomycete Leucocoprinus gongylophorus sustain large colonies of leaf-cutting ants by degrading the plant material collected by the ants. Recent studies have shown that enzyme activity in these gardens is primarily targeted toward starch, proteins and the pectin matrix......, we measured the changes in enzyme activity after a controlled shift in fungal substrate offered to six laboratory colonies of Atta cephalotes. An ant diet consisting exclusively of grains of parboiled rice rapidly increased the activity of endo-proteinases and some of the pectinases attacking the...... associated with cell walls, rather than toward structural cell wall components such as cellulose and hemicelluloses. Substrate constituents are also known to be sequentially degraded in different sections of the fungus garden. To test the plasticity in the extracellular expression of fungus-garden enzymes...

  2. Islamization of Knowledge: A Comparative Analysis of the Conceptions of AI-Attas and AI- Fārūqī

    Directory of Open Access Journals (Sweden)

    Rosnani Hashim

    2000-06-01

    Full Text Available There has been a lot of discussion and debate on the issue of Islamization of Contemporary Knowledge among Muslim intellectuals. Two Muslim thinkers, namely al-Attas and al-Fārūqī were foremost in the attempt to conceptualise the problem of the Muslim Ummah and the issue of Islamization of knowledge as an epistemological and socio-political solution. This article aims to examine, compare and analyse the ideas of both scholars with respect to the various interpretations of the concept of Islamization of knowledge their definition of the concept, their philosophical framework, and their methodology for achieving the goals of Islamization. It aims at understanding the similarities and differences and the strengths and weaknesses of their conceptions, philosophical framework and methodology. This paper also explores the possibility of reconciliation between their ideas in the hope of further advancing the cause of Islamization of knowledge.

  3. The Postpharyngeal Gland: Specialized Organ for Lipid Nutrition in Leaf-Cutting Ants.

    Science.gov (United States)

    Decio, Pâmela; Vieira, Alexsandro Santana; Dias, Nathalia Baptista; Palma, Mario Sergio; Bueno, Odair Correa

    2016-01-01

    There are several hypotheses about the possible functions of the postpharyngeal gland (PPG) in ants. The proposed functions include roles as cephalic or gastric caeca and diverticulum of the digestive tract, mixing of hydrocarbons, nestmate recognition, feeding larvae, and the accumulation of lipids inside this gland, whose origin is contradictory. The current study aimed to investigate the functions of these glands by examining the protein expression profile of the PPGs of Atta sexdens rubropilosa (Hymenoptera, Formicidae). Mated females received lipid supplementation and their glands were extracted and analyzed using a proteomic approach. The protocol used combined two-dimensional electrophoresis and shotgun strategies, followed by mass spectrometry. We also detected lipid β-oxidation by immunofluorescent marking of acyl-CoA dehydrogenase. Supplying ants with lipids elicited responses in the glandular cells of the PPG; these included increased expression of proteins related to defense mechanisms and signal transduction and reorganization of the cytoskeleton due to cell expansion. In addition, some proteins in PPG were overexpressed, especially those involved in lipid and energy metabolism. Part of the lipids may be reduced, used for the synthesis of fatty alcohol, transported to the hemolymph, or may be used as substrate for the synthesis of acetyl-CoA, which is oxidized to form molecules that drive oxidative phosphorylation and produce energy for cellular metabolic processes. These findings suggest that this organ is specialized for lipid nutrition of adult leaf-cutting ants and characterized like a of diverticulum foregut, with the ability to absorb, store, metabolize, and mobilize lipids to the hemolymph. However, we do not rule out that the PPG may have other functions in other species of ants. PMID:27149618

  4. Ants can learn to forage on one-way trails.

    Directory of Open Access Journals (Sweden)

    Pedro Leite Ribeiro

    Full Text Available The trails formed by many ant species between nest and food source are two-way roads on which outgoing and returning workers meet and touch each other all along. The way to get back home, after grasping a food load, is to take the same route on which they have arrived from the nest. In many species such trails are chemically marked by pheromones providing orientation cues for the ants to find their way. Other species rely on their vision and use landmarks as cues. We have developed a method to stop foraging ants from shuttling on two-way trails. The only way to forage is to take two separate roads, as they cannot go back on their steps after arriving at the food or at the nest. The condition qualifies as a problem because all their orientation cues -- chemical, visual or any other -- are disrupted, as all of them cannot but lead the ants back to the route on which they arrived. We have found that workers of the leaf-cutting ant Atta sexdens rubropilosa can solve the problem. They could not only find the alternative way, but also used the unidirectional traffic system to forage effectively. We suggest that their ability is an evolutionary consequence of the need to deal with environmental irregularities that cannot be negotiated by means of excessively stereotyped behavior, and that it is but an example of a widespread phenomenon. We also suggest that our method can be adapted to other species, invertebrate and vertebrate, in the study of orientation, memory, perception, learning and communication.

  5. The Postpharyngeal Gland: Specialized Organ for Lipid Nutrition in Leaf-Cutting Ants

    Science.gov (United States)

    Decio, Pâmela; Vieira, Alexsandro Santana; Dias, Nathalia Baptista; Palma, Mario Sergio; Bueno, Odair Correa

    2016-01-01

    There are several hypotheses about the possible functions of the postpharyngeal gland (PPG) in ants. The proposed functions include roles as cephalic or gastric caeca and diverticulum of the digestive tract, mixing of hydrocarbons, nestmate recognition, feeding larvae, and the accumulation of lipids inside this gland, whose origin is contradictory. The current study aimed to investigate the functions of these glands by examining the protein expression profile of the PPGs of Atta sexdens rubropilosa (Hymenoptera, Formicidae). Mated females received lipid supplementation and their glands were extracted and analyzed using a proteomic approach. The protocol used combined two-dimensional electrophoresis and shotgun strategies, followed by mass spectrometry. We also detected lipid β-oxidation by immunofluorescent marking of acyl-CoA dehydrogenase. Supplying ants with lipids elicited responses in the glandular cells of the PPG; these included increased expression of proteins related to defense mechanisms and signal transduction and reorganization of the cytoskeleton due to cell expansion. In addition, some proteins in PPG were overexpressed, especially those involved in lipid and energy metabolism. Part of the lipids may be reduced, used for the synthesis of fatty alcohol, transported to the hemolymph, or may be used as substrate for the synthesis of acetyl-CoA, which is oxidized to form molecules that drive oxidative phosphorylation and produce energy for cellular metabolic processes. These findings suggest that this organ is specialized for lipid nutrition of adult leaf-cutting ants and characterized like a of diverticulum foregut, with the ability to absorb, store, metabolize, and mobilize lipids to the hemolymph. However, we do not rule out that the PPG may have other functions in other species of ants. PMID:27149618

  6. Cellulose-Enriched Microbial Communities from Leaf-Cutter Ant (Atta colombica) Refuse Dumps Vary in Taxonomic Composition and Degradation Ability.

    Science.gov (United States)

    Lewin, Gina R; Johnson, Amanda L; Soto, Rolando D Moreira; Perry, Kailene; Book, Adam J; Horn, Heidi A; Pinto-Tomás, Adrián A; Currie, Cameron R

    2016-01-01

    Deconstruction of the cellulose in plant cell walls is critical for carbon flow through ecosystems and for the production of sustainable cellulosic biofuels. Our understanding of cellulose deconstruction is largely limited to the study of microbes in isolation, but in nature, this process is driven by microbes within complex communities. In Neotropical forests, microbes in leaf-cutter ant refuse dumps are important for carbon turnover. These dumps consist of decaying plant material and a diverse bacterial community, as shown here by electron microscopy. To study the portion of the community capable of cellulose degradation, we performed enrichments on cellulose using material from five Atta colombica refuse dumps. The ability of enriched communities to degrade cellulose varied significantly across refuse dumps. 16S rRNA gene amplicon sequencing of enriched samples identified that the community structure correlated with refuse dump and with degradation ability. Overall, samples were dominated by Bacteroidetes, Gammaproteobacteria, and Betaproteobacteria. Half of abundant operational taxonomic units (OTUs) across samples were classified within genera containing known cellulose degraders, including Acidovorax, the most abundant OTU detected across samples, which was positively correlated with cellulolytic ability. A representative Acidovorax strain was isolated, but did not grow on cellulose alone. Phenotypic and compositional analyses of enrichment cultures, such as those presented here, help link community composition with cellulolytic ability and provide insight into the complexity of community-based cellulose degradation. PMID:26999749

  7. Cellulose-Enriched Microbial Communities from Leaf-Cutter Ant (Atta colombica) Refuse Dumps Vary in Taxonomic Composition and Degradation Ability

    Science.gov (United States)

    Lewin, Gina R.; Johnson, Amanda L.; Soto, Rolando D. Moreira; Perry, Kailene; Book, Adam J.; Horn, Heidi A.; Pinto-Tomás, Adrián A.; Currie, Cameron R.

    2016-01-01

    Deconstruction of the cellulose in plant cell walls is critical for carbon flow through ecosystems and for the production of sustainable cellulosic biofuels. Our understanding of cellulose deconstruction is largely limited to the study of microbes in isolation, but in nature, this process is driven by microbes within complex communities. In Neotropical forests, microbes in leaf-cutter ant refuse dumps are important for carbon turnover. These dumps consist of decaying plant material and a diverse bacterial community, as shown here by electron microscopy. To study the portion of the community capable of cellulose degradation, we performed enrichments on cellulose using material from five Atta colombica refuse dumps. The ability of enriched communities to degrade cellulose varied significantly across refuse dumps. 16S rRNA gene amplicon sequencing of enriched samples identified that the community structure correlated with refuse dump and with degradation ability. Overall, samples were dominated by Bacteroidetes, Gammaproteobacteria, and Betaproteobacteria. Half of abundant operational taxonomic units (OTUs) across samples were classified within genera containing known cellulose degraders, including Acidovorax, the most abundant OTU detected across samples, which was positively correlated with cellulolytic ability. A representative Acidovorax strain was isolated, but did not grow on cellulose alone. Phenotypic and compositional analyses of enrichment cultures, such as those presented here, help link community composition with cellulolytic ability and provide insight into the complexity of community-based cellulose degradation. PMID:26999749

  8. Cellulose-Enriched Microbial Communities from Leaf-Cutter Ant (Atta colombica Refuse Dumps Vary in Taxonomic Composition and Degradation Ability.

    Directory of Open Access Journals (Sweden)

    Gina R Lewin

    Full Text Available Deconstruction of the cellulose in plant cell walls is critical for carbon flow through ecosystems and for the production of sustainable cellulosic biofuels. Our understanding of cellulose deconstruction is largely limited to the study of microbes in isolation, but in nature, this process is driven by microbes within complex communities. In Neotropical forests, microbes in leaf-cutter ant refuse dumps are important for carbon turnover. These dumps consist of decaying plant material and a diverse bacterial community, as shown here by electron microscopy. To study the portion of the community capable of cellulose degradation, we performed enrichments on cellulose using material from five Atta colombica refuse dumps. The ability of enriched communities to degrade cellulose varied significantly across refuse dumps. 16S rRNA gene amplicon sequencing of enriched samples identified that the community structure correlated with refuse dump and with degradation ability. Overall, samples were dominated by Bacteroidetes, Gammaproteobacteria, and Betaproteobacteria. Half of abundant operational taxonomic units (OTUs across samples were classified within genera containing known cellulose degraders, including Acidovorax, the most abundant OTU detected across samples, which was positively correlated with cellulolytic ability. A representative Acidovorax strain was isolated, but did not grow on cellulose alone. Phenotypic and compositional analyses of enrichment cultures, such as those presented here, help link community composition with cellulolytic ability and provide insight into the complexity of community-based cellulose degradation.

  9. [Occurrence and biological characteristics of parasitoid phorids (Diptera: Phoridae) of the leaf-cutting ant Atta laevigata (Smith) (Hymenoptera: Formicidae) in Porto Nacional, TO, Brazil].

    Science.gov (United States)

    Bragança, Marcos A L; Medeiros, Zodja C S

    2006-01-01

    The purpose of this study was to verify the occurrence of parasitism in Atta laevigata (Smith) by phorids in Porto Nacional, Tocantins, Brazil and to evaluate some biological characteristics of those flies. From October/2002 to September/2003, at 15-day intervals, 22 samplings were carried out (149.5 +/- 82.9 workers each) comprising 3,704 ants. In the laboratory, the ants were distributed in groups of five individuals per petri dish and maintained at temperature of 25 +/- 1 masculineC and 80 +/- 5% of RH. They were fed daily with a 50% honey solution until death. The total of 106 workers (2.8%), collected with or without load (plant fragment), were parasitized by phorids: 72 workers (68%) were parasitized by Apocephalus vicosae Disney, 28 individuals (26.4%) by Neodohrniphora erthali Brown, and six (5.6%) by Apocephalus attophilus Borgmeier. The higher parasitism rates by A. vicosae (3.9-5.4%) were observed during the dry season (June-August), while the parasitism by N. erthali was lower than 2.3% throughout the year. The bigger workers were parasitized by bigger parasitoid N. erthali or by parasitoid with larger number of larvae A. attophilus. The occurrence of three phorid species in Tocantins broadens the distribution of these flies in Brazil. The development of A. vicosae larva within the thorax of the host as well as the rupture between the ant pronotum and propleuron so that the emergence of the fly can take place are characteristics not yet described on parasitism of leaf-cutting ants by phorids. PMID:18575704

  10. Soil moisture and excavation behaviour in the Chaco leaf-cutting ant (Atta vollenweideri: digging performance and prevention of water inflow into the nest.

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    Steffen Pielström

    Full Text Available The Chaco leaf-cutting ant Atta vollenweideri is native to the clay-heavy soils of the Gran Chaco region in South America. Because of seasonal floods, colonies are regularly exposed to varying moisture across the soil profile, a factor that not only strongly influences workers' digging performance during nest building, but also determines the suitability of the soil for the rearing of the colony's symbiotic fungus. In this study, we investigated the effects of varying soil moisture on behaviours associated with underground nest building in A. vollenweideri. This was done in a series of laboratory experiments using standardised, plastic clay-water mixtures with gravimetric water contents ranging from relatively brittle material to mixtures close to the liquid limit. Our experiments showed that preference and group-level digging rate increased with increasing water content, but then dropped considerably for extremely moist materials. The production of vibrational recruitment signals during digging showed, on the contrary, a slightly negative linear correlation with soil moisture. Workers formed and carried clay pellets at higher rates in moist clay, even at the highest water content tested. Hence, their weak preference and low group-level excavation rate observed for that mixture cannot be explained by any inability to work with the material. More likely, extremely high moistures may indicate locations unsuitable for nest building. To test this hypothesis, we simulated a situation in which workers excavated an upward tunnel below accumulated surface water. The ants stopped digging about 12 mm below the interface soil/water, a behaviour representing a possible adaptation to the threat of water inflow field colonies are exposed to while digging under seasonally flooded soils. Possible roles of soil water in the temporal and spatial pattern of nest growth are discussed.

  11. Branch Width and Height Influence the Incorporation of Branches into Foraging Trails and Travel Speed in Leafcutter Ants Atta cephalotes (L.) (Hymenoptera: Formicidae).

    Science.gov (United States)

    Freeman, B M; Chaves-Campos, J

    2016-06-01

    Fallen branches are often incorporated into Atta cephalotes (L.) foraging trails to optimize leaf tissue transport rates and economize trail maintenance. Recent studies in lowlands show laden A. cephalotes travel faster across fallen branches than on ground, but more slowly ascending or descending a branch. The latter is likely because (1) it is difficult to travel up or downhill and (2) bottlenecks occur when branches are narrower than preceding trail. Hence, both branch height and width should determine whether branches decrease net travel times, but no study has evaluated it yet. Laden A. cephalotes were timed in relation to branch width and height across segments preceding, accessing, across, and departing a fallen branch in the highlands of Costa Rica. Ants traveled faster on branches than on cleared segments of trunk-trail, but accelerated when ascending or descending the branch-likely because of the absence of bottlenecks during the day in the highlands. Branch size did not affect ant speed in observed branches; the majority of which (22/24) varied from 11 to 120 mm in both height and width (average 66 mm in both cases). To determine whether ants exclude branches outside this range, ants were offered the choice between branches within this range and branches that were taller/wider than 120 mm. Ants strongly preferred the former. Our results indicate that A. cephalotes can adjust their speed to compensate for the difficulty of traveling on branch slopes. More generally, branch size should be considered when studying ant foraging efficiency. PMID:26830434

  12. Energy substrate used by workers of leaf-cutting ants during nest excavation

    OpenAIRE

    Roberto S. Camargo; Juliane F. S. Lopes; Luiz C. Forti; Somera, Alexandre F.; Mauricio Bacci Jr

    2013-01-01

    Energy substrate used by workers of leaf-cutting ants during nest excavation. In this study we aimed to ascertain whether leaf-cutting ant workers lose body reserves (fat or sugars) as a function of nest excavation. For each treatment, we isolated 10 workers of Atta sexdens into two experimental groups, Control (C- without excavation) and Soil (S- with excavation), which were kept for different time intervals (0, 24, 48 or 72 hours), totaling 700 tested workers. We then determined the concent...

  13. Atratividade da isca granulada de polpa de fruto do jatobá para saúva-limão, no campo Attractiveness of the granulated bait of jatobá's fruit pulp to the leaf- cutting ant, in the field

    Directory of Open Access Journals (Sweden)

    Maria Lucia França Teixeira

    2008-08-01

    Full Text Available A atratividade da polpa do fruto de jatobá para saúva-limão foi avaliada tendo como parâmetro comparativo a polpa cítrica desidratada, utilizada como veículo por diversas marcas comerciais. O experimento foi conduzido em quatro formigueiros de saúva-limão em canteiros gramados com espécies arbóreas. As iscas de jatobá e de polpa cítrica desidratada, ambas sem princípio ativo, foram confeccionadas em grânulos com formato e diâmetro semelhantes aos das iscas granuladas comerciais. As iscas de jatobá foram mais atrativas para as operárias de saúva-limão, que fizeram o primeiro contato aos 17s, em contraste com os 29s gastos para o primeiro contato com as iscas de polpa cítrica. As iscas de jatobá também começaram a ser carregadas mais cedo, aos 26s, sendo que as iscas de polpa cítrica foram carregadas 48s mais tarde. A grande aceitação do jatobá foi reforçada pelo menor tempo para o encerramento dos testes, 5min 39s, contrastando com os 11min 17s necessários para o encerramento do teste com a polpa cítrica. A polpa do fruto do jatobá foi mais atrativa para saúva-limão do que a polpa cítrica desidratada.Attractiveness of the leaf-cutting ant, Atta sexdens rubropilosa to jatobá's fruit pulp was evaluated, having the dehydrated citrus pulp as comparative parameter, used as vehicle by several commercial brands. The experiment was conducted on four nests of leaf-cutting ants on lawns with arboreal species. Jatobá baits and dehydrated citric pulp both without active principle were made into granules with form and diameter similar to the commercial granulated baits. Jatobá baits were more attractive to the laborers of leaf-cutting ants which made the first contact after 17s, contrasting with 29s before the first contact with citric pulp baits. Jatobá baits were also carried earlier, after 26s, while citric pulp baits were carried 48s later. The great acceptance of jatobá baits was strengthened by the short time to

  14. Secondary seed dispersal of Ricinus communis Linnaeus (Euphorbiaceae) by ants in secondary growth vegetation in Minas Gerais Dispersão secundária de sementes de Ricinus communis Linnaeus (Euphorbiaceae) por formigas em vegetação secundária em Minas Gerais

    OpenAIRE

    Mário Marcos do Espírito Santo

    2007-01-01

    In this study, I tested the efficacy of ants as secondary seed dispersers of Ricinus communis in southeastern Brazil. In a natural population of 143 individuals, I determined the ballistic dispersal distance for 62 seeds and 100 additional seeds were experimentally offered to ants in groups of ten seeds along a transect of 50 m. Fifty-three seeds were removed by ants, mainly by the leafcutter Atta sexdens (90.4%). The dispersal distance by ants was high, compared to the global average (4.38 m...

  15. Growth of symbiont fungi of some higher attine ants in mineral medium Crescimento do fungo simbionte de alguns attine superiores em meio mineral

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    Alci Enimar Loeck

    2004-02-01

    Full Text Available Bioassays were conducted to verify the possibility of culturing the symbiont fungus of some higher attine in mineral medium and finding out the optimum pH value for their satisfactory mycelial growth. Three organic media and one mineral medium were inoculated with isolates from Atta sexdens piriventris and Acromyrmex heyeri. In mineral medium different values of pH (4.0, 5.0, 6.0 and 7.0 were tested with isolates from A. laevigata and A. laticeps. The behavior of isolates (colony diameter was different in the mineral medium. However, even the one which grew the least of all provided enough mycelial for RAPD analysis. The best range of pH for fungal growth in mineral medium was between 4.0 and 5.0Foram conduzidos bioensaios para verificar a possibilidade de cultivar o fungo simbionte de alguns attine superiores em meio mineral e obter um valor de pH ótimo para o seu crescimento micelial. Três meios orgânicos e um meio mineral foram testados, avaliando-se o crescimento (diâmetro da colônia de isolados de fungos de Atta sexdens piriventris e Acromyrmex heyeri. No meio mineral, diferentes valores de pH (4,0, 5,0, 6,0 and 7,0 foram avaliados, por meio do mesmo parâmetro anterior, com isolados de fungos de A. laevigata e A. laticeps. No meio mineral, os isolados testados apresentaram crescimento diferenciado, entretanto mesmo aquele que menos cresceu, forneceu material suficiente para as análises de RAPD. No mesmo meio, verificou-se que a melhor faixa de pH para o crescimento micelial está entre 4,0 e 5,0.

  16. Seminal fluid enhances sperm viability in the leafcutter ant Atta colombica

    DEFF Research Database (Denmark)

    Den Boer, Susanne Petronella A; Boomsma, Jacobus Jan; Baer, Boris

    2008-01-01

    in life, although they may live and produce fertilized eggs for several decades. The mating biology and life history of these ants therefore suggests that the major function of seminal fluid is to maximize sperm viability during copulation, sperm transfer, and initial sperm storage. We tested this...

  17. Secondary seed dispersal of Ricinus communis Linnaeus (Euphorbiaceae by ants in secondary growth vegetation in Minas Gerais Dispersão secundária de sementes de Ricinus communis Linnaeus (Euphorbiaceae por formigas em vegetação secundária em Minas Gerais

    Directory of Open Access Journals (Sweden)

    Mário Marcos do Espírito Santo

    2007-12-01

    Full Text Available In this study, I tested the efficacy of ants as secondary seed dispersers of Ricinus communis in southeastern Brazil. In a natural population of 143 individuals, I determined the ballistic dispersal distance for 62 seeds and 100 additional seeds were experimentally offered to ants in groups of ten seeds along a transect of 50 m. Fifty-three seeds were removed by ants, mainly by the leafcutter Atta sexdens (90.4%. The dispersal distance by ants was high, compared to the global average (4.38 m ± 0.74 m vs. 0.96 m, but was lower than the ballistic distance (7.27 m ± 0.13 m. Ants increased the total dispersal distance (8.66 m ± 0.60 m, but the main benefit for the plant was the directed dispersal, with seed deposition on the enriched soil of ant nests.Este estudo testou a eficiência de formigas como dispersores secundários de Ricinus communis no Brasil. Em uma população natural de 143 indivíduos, a distância de dispersão balística foi determinada para 62 sementes. Além disso, 100 sementes adicionais foram oferecidas a formigas em grupos de 10, ao longo de um transecto de 50 m. Cinqüenta e três sementes foram removidas por formigas, principalmente pela formiga-cortadeira Atta sexdens (90,4%. A distância de dispersão por formigas foi alta se comparada à média global (4,38m ± 0,74 m vs. 0,96 m, porém menor que a distância de dispersão balística (7,27 m ± 0,13 m. As formigas aumentaram a distância de dispersão total (8,66 m ± 0,60 m, mas o principal benefício para a planta foi a dispersão direcionada, com a deposição das sementes no solo enriquecido encontrado nos ninhos das formigas.

  18. Why are there few seedlings beneath the myrmecophyte Triplaris americana?

    Science.gov (United States)

    Larrea-Alcázar, Daniel M.; Simonetti, Javier A.

    2007-07-01

    We compared the relative importance of chemical alellopathy, pruning behaviour of resident ants and other non-related agents to ant-plant mutualism for seedling establishment beneath Triplaris americana L. (Polygonaceae), a myrmecophyte plant. We also included a preliminary analysis of effects of fragmentation on these ecological processes. Seeds and seedlings of Theobroma cacao L. (Sterculiaceae) were used as the target species in all experiments. Leaf-tissue extracts of the myrmecophyte plant did not inhibit germination of cacao seeds. Resident Pseudomyrmex triplarinus Weddell (Pseudomyrmecinae) ants did not remove seeds under the canopy of their host plants. The main seed consumer was the leaf-cutting ant Atta sexdens L. (Myrmicinae). Leaves of cacao seedlings were partially or totally pruned by Pseudomyrmex ants mainly in forest fragments studied. We offer evidence pointing to the possibility that the absence of seedlings beneath Triplaris may result from effects of both ant species. We discuss the benefits of pruning behaviour for the resident ant colony and the effects of ant-ant interactions on seedling establishment beneath this ant-plant system.

  19. Identification and expression of capa gene in the fire ant, Solenopsis invicta.

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    Man-Yeon Choi

    Full Text Available Recent genome analyses suggested the absence of a number of neuropeptide genes in ants. One of the apparently missing genes was the capa gene. Capa gene expression in insects is typically associated with the neuroendocrine system of abdominal ganglia; mature CAPA peptides are known to regulate diuresis and visceral muscle contraction. The apparent absence of the capa gene raised questions about possible compensation of these functions. In this study, we re-examined this controversial issue and searched for a potentially unrecognized capa gene in the fire ant, Solenopsis invicta. We employed a combination of data mining and a traditional PCR-based strategy using degenerate primers designed from conserved amino acid sequences of insect capa genes. Our findings demonstrate that ants possess and express a capa gene. As shown by MALDI-TOF mass spectrometry, processed products of the S. invicta capa gene include three CAPA periviscerokinins and low amounts of a pyrokinin which does not have the C-terminal WFGPRLa motif typical of CAPA pyrokinins in other insects. The capa gene was found with two alternative transcripts in the CNS. Within the ventral nerve cord, two capa neurons were immunostained in abdominal neuromeres 2-5, respectively, and projected into ventrally located abdominal perisympathetic organs (PSOs, which are the major hormone release sites of abdominal ganglia. The ventral location of these PSOs is a characteristic feature and was also found in another ant, Atta sexdens.

  20. Ethnopharmacological survey among migrants living in the Southeast Atlantic Forest of Diadema, São Paulo, Brazil

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    Rodrigues Eliana

    2010-10-01

    Full Text Available Abstract Background Understanding how people of diverse cultural backgrounds have traditionally used plants and animals as medicinal substances during displacements is one of the most important objectives of ethnopharmacological studies. An ethnopharmacological survey conducted among migrants living in the Southeast Atlantic Forest remnants (Diadema, São Paulo, Brazil is presented herein. Methods Ethnographical methods were used to select and interview the migrants, and botanical and zoological techniques were employed to collect the indicated resources. Results We interviewed five migrants who described knowledge on 12 animals and 85 plants. Only 78 plants were present in Diadema, they belong to 37 taxonomic families; 68 were used exclusively for medicinal purposes, whereas 10 were reported to be toxic and/or presented some restriction of use. These taxa were grouped into 12 therapeutic categories (e.g., gastrointestinal disturbances, inflammatory processes or respiratory problems based on the 41 individual complaints cited by the migrants. While the twelve animal species were used by the migrants to treat nine complaints; these were divided into six categories, the largest of which related to respiratory problems. None of the animal species and only 57 of the 78 plant species analysed in the present study were previously reported in the pharmacological literature; the popular knowledge concurred with academic findings for 30 of the plants. The seven plants [Impatiens hawkeri W. Bull., Artemisia canphorata Vill., Equisetum arvensis L., Senna pendula (Humb. & Bonpl. ex Willd. H.S. Irwin & Barneby, Zea mays L., Fevillea passiflora Vell. and Croton fuscescens Spreng] and the two animals (Atta sexdens and Periplaneta americana that showed maintenance of use among migrants during their displacement in Brazilian territory, have not been studied by pharmacologists yet. Conclusions Thus, they should be highlighted and focused in further pharmacology

  1. Protein content of leaf-cutting ant queens before the nuptial flight and during the post-claustral phase

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    Edypo Jacob Silva

    2014-12-01

    Full Text Available Protein content of leaf-cutting ant queens before the nuptial flight and during the post-claustral phase. This study evaluated the crude protein content of queens of Atta sexdens before the nuptial flight and after the claustral phase in laboratory and field colonies. The hypothesis was that protein is used for survival of the queen and for early colony growth during the claustral phase. Additionally, the nest morphology, live biomass and adult population of field colonies were evaluated. Crude protein was determined by digestion of the organic material with sulfuric acid at high temperatures. The mean crude protein content was 123.23 ± 11.20 mg for females before the nuptial flight and 70.44 ± 12.21 mg for laboratory-reared queens after the claustral phase. The post-claustral crude protein content of field-collected queen was 55.90 ± 9.18 mg. With respect to the loss of crude protein as a function of duration of the claustral phase, laboratory-reared queens lost 52.79 mg and field-collected queens lost 67.33 mg compared to females before the nuptial flight. A positive linear correlation was observed between the weight of field-collected queens (256.4 ± 36.3 mg and colony biomass (13.02 ± 9.12 g, but there was no correlation between biomass and nest depth (13.11 ± 3.82 cm. As expected, the present results support the hypothesis that protein is used for survival of the queen and for early colony growth, as demonstrated by the reduction in crude protein content as a function of duration of the claustral phase. To our knowledge, this is the first study to provide data of the dynamics of protein reserves in leaf-cutting ant queens during the claustral phase.

  2. Considerations for assessing maximum critical temperatures in small ectothermic animals: insights from leaf-cutting ants.

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    Pedro Leite Ribeiro

    Full Text Available The thermal limits of individual animals were originally proposed as a link between animal physiology and thermal ecology. Although this link is valid in theory, the evaluation of physiological tolerances involves some problems that are the focus of this study. One rationale was that heating rates shall influence upper critical limits, so that ecological thermal limits need to consider experimental heating rates. In addition, if thermal limits are not surpassed in experiments, subsequent tests of the same individual should yield similar results or produce evidence of hardening. Finally, several non-controlled variables such as time under experimental conditions and procedures may affect results. To analyze these issues we conducted an integrative study of upper critical temperatures in a single species, the ant Atta sexdens rubropiosa, an animal model providing large numbers of individuals of diverse sizes but similar genetic makeup. Our specific aims were to test the 1 influence of heating rates in the experimental evaluation of upper critical temperature, 2 assumptions of absence of physical damage and reproducibility, and 3 sources of variance often overlooked in the thermal-limits literature; and 4 to introduce some experimental approaches that may help researchers to separate physiological and methodological issues. The upper thermal limits were influenced by both heating rates and body mass. In the latter case, the effect was physiological rather than methodological. The critical temperature decreased during subsequent tests performed on the same individual ants, even one week after the initial test. Accordingly, upper thermal limits may have been overestimated by our (and typical protocols. Heating rates, body mass, procedures independent of temperature and other variables may affect the estimation of upper critical temperatures. Therefore, based on our data, we offer suggestions to enhance the quality of measurements, and offer

  3. Energy substrate used by workers of leaf-cutting ants during nest excavation

    Directory of Open Access Journals (Sweden)

    Roberto S. Camargo

    2013-12-01

    Full Text Available Energy substrate used by workers of leaf-cutting ants during nest excavation. In this study we aimed to ascertain whether leaf-cutting ant workers lose body reserves (fat or sugars as a function of nest excavation. For each treatment, we isolated 10 workers of Atta sexdens into two experimental groups, Control (C- without excavation and Soil (S- with excavation, which were kept for different time intervals (0, 24, 48 or 72 hours, totaling 700 tested workers. We then determined the concentration of soluble carbohydrates and total lipid content in them. The total carbohydrates were determined colorimetrically, based on the reaction between carbohydrates and sulfuric acid-phenol. For determination of lipids, the insects were immersed in organic solvent until they reached a constant weight. Our results showed that carbohydrates are consumed during nest excavation activities. In the experimental groups S24, S48 and S72, there was an average reduction of 5.82 (20.42%, 14.31 (44.96% and 13.27 (43.96% µ.mg-1 in soluble sugar when compared with the experimental groups that did not excavate. Furthermore, the lipids were not used during this activity. With respect to dry mass of the workers, their values were C0 = 8%, C24 = 10.4%, C48 = 9.2%, C72 = 10%, S24 = 9.2%, S48 = 8.7% and S72 = 8.5%. Our results show experimentally that the source of energy for nest excavation is carbohydrates, whereas lipids are conserved for other activities.

  4. Are ant assemblages of Brazilian veredas characterised by location or habitat type?

    Science.gov (United States)

    Costa-Milanez, C B; Lourenço-Silva, G; Castro, P T A; Majer, J D; Ribeiro, S P

    2014-02-01

    Wetland areas in the Brazilian Cerrado, known as "veredas", represent ecosystems formed on sandy soils with high concentrations of peat, and are responsible for the recharge of aquiferous reservoirs. They are currently under threat by various human activities, most notably the clearing of vegetation for Eucalyptus plantations. Despite their ecological importance and high conservation value, little is known about the actual effects of human disturbance on the animal community. To assess how habitat within different veredas, and plantations surrounding them affect ant assemblages, we selected four independent vereda locations, two being impacted by Eucalyptus monoculture (one younger and one mature plantation) and two controls, where the wetland was surrounded by cerrado vegetation. Ant sampling was conducted in May 2010 (dry season) using three complementary methods, namely baits, pitfall traps, and hand collection, in the wetland and in the surrounding habitats. A total of 7,575 ants were sampled, belonging to seven subfamilies, 32 genera and 124 species. Ant species richness and abundance did not differ between vereda locations, but did between the habitats. When impacted by the monoculture, ant species richness and abundance decreased in wetlands, but were less affected in the cerrado habitat. Ant species composition differed between the three habitats and between vereda locations. Eucalyptus plantations had an ant species composition defined by high dominance of Pheidole sp. and Solenopsis invicta, while natural habitats were defined by Camponotus and Crematogaster species. Atta sexdens was strictly confined to native habitats of non-impacted "veredas". Eucalyptus monocultures require high quantities of water in the early stages, which may have caused a decrease in groundwater level in the wetland, allowing hypogeic ants such as Labidus praedator to colonise this habitat. PMID:25055090

  5. Random sperm use and genetic effects on worker caste fate in Atta colombica leaf-cutting ants

    DEFF Research Database (Denmark)

    Holman, Luke; Stürup, Marlene; Trontti, Kalevi; Boomsma, Jacobus J

    2011-01-01

    genotyping revealed how sperm number translated into paternity of eggs and adult workers. We demonstrate that fertilization success is directly related to sperm numbers, that stored sperm are well-mixed and that egg paternity is constant over time. Moreover, worker size was found to have a considerable...

  6. Specificity in chemical profiles of workers, brood and mutualistic fungi in Atta, Acromyrmex, and Sericomyrmex fungus-growing ants

    DEFF Research Database (Denmark)

    Richard, Freddie-Jeanne; Poulsen, Michael; Drijfhout, Falko; Jones, Graeme; Boomsma, Jacobus Jan

    2007-01-01

    , acetates, acids, and esters. The chemical profiles in all three species are likely to be sufficiently different to allow discrimination at the species and colony level and sufficiently similar within colonies to generate a relatively constant colony-specific chemical gestalt. The relative likelihood of...

  7. Distorsión local de campo magnético terrestre como una propuesta de manejo de una especie de hormiga arriera atta spp. (hymenoptera: formicidae)

    OpenAIRE

    Paz Penagos, Hernán; Vargas Rodríguez, Mauricio Alexander; Forero Bermúdez, Oscar; Pabón Caviativa, Juan Francisco; Plaza Martínez, Jovan

    2012-01-01

    Los estudios sobre la orientación espacial de los insectos sociales (abejas, termitas y hormigas) en situaciones de búsqueda, recolección y transporte de alimento han recibido considerable atención en los últimos años. Los propósitos han sido aprender acerca de ellos para aplicarlos a la robótica (multiagentes) y al control ecológico de plagas. Sin embargo, aún se conoce poco sobre los tipos de mecanismos de orientación y su integración en dichos insectos. En este artículo se describen alguno...

  8. Local distortion of the earth’s magnetic field as a proposal for handling the leafcutter ant species Atta spp. (Hymenoptera: Formicidae)

    OpenAIRE

    Hernán Paz Penagos; Mauricio Alexander Vargas Rodríguez; Oscar Forero Bermúdez; Juan Francisco Pabón Caviativa; Jovan Plaza Martínez

    2012-01-01

    Studies regarding the spatial orientation of social insects (bees, termites and ants) concerning their search for food, foraging and transporting it have received considerable attention during the last few years. Such studies have been aimed at learning so as to apply it to robotics (multiagents) and ecological pest control. However, little is known about the types of orientation mechanism and their integration in such insects. This article presents some geomagnetic field detection studies de...

  9. Local distortion of the earth’s magnetic field as a proposal for handling the leafcutter ant species Atta spp. (Hymenoptera: Formicidae

    Directory of Open Access Journals (Sweden)

    Hernán Paz Penagos

    2012-08-01

    Full Text Available Studies regarding the spatial orientation of social insects (bees, termites and ants concerning their search for food, foraging and transporting it have received considerable attention during the last few years. Such studies have been aimed at learning so as to apply it to robotics (multiagents and ecological pest control. However, little is known about the types of orientation mechanism and their integration in such insects. This article presents some geomagnetic field detection studies dealing with controlling them by magnetotaxis or orientation experiments in Sasaima (Cundinamarca to formulate an ecological management proposal for ants from this species which greatly affect Colombian agriculture.

  10. Fóridos (Díptera: Phoridae) asociados al hábitat de hormigas cortadoras de hojas (Atta cephalotes y Acromyrmex octospinosus) y sus patrones de localización en un bosque seco tropical andino

    OpenAIRE

    Uribe Celis, Soraya

    2013-01-01

    Resumen:Siempre que se escucha hablar de las moscas viene a la mente de las personas las desagradables moscas domesticas o las perturbadoras moscas del establo. Sin embargo existe un grupo de moscas casi imperceptibles por su pequeño tamaño, conocidas como fóridos o moscas jorobadas, este interesante grupo ha sido poco estudiado. La información que se posee sobre éste nos muestra que son de gran importancia ecológica ya que su historia natural es muy variada ésta va desde individuos saprófago...

  11. A colony-level response to disease control in a leaf-cutting ant

    OpenAIRE

    Brown, Mark

    2002-01-01

    PUBLISHED Parasites and pathogens often impose significant costs on their hosts. This is particularly true for social organisms, where the genetic structure of groups and the accumulation of contaminated waste facilitate disease transmission. In response, hosts have evolved many mechanisms of defence against parasites. Here we present evidence that Atta colombica, a leaf-cutting ant, may combat Escovopsis, a dangerous parasite of Atta?s garden fungus, through a colony-level behavioural res...

  12. Differences in forage-acquisition and fungal enzyme activity contribute to niche segregation in Panamanian leaf-cutting ants

    DEFF Research Database (Denmark)

    Kooij, Pepijn Wilhelmus; Liberti, Joanito; Giampoudakis, Konstantinos;

    2014-01-01

    activities of twelve fungus garden decomposition enzymes, belonging to the amylases, cellulases, hemicellulases, pectinases and proteinases, and show that average enzyme activity per unit of fungal mass in Atta gardens is lower than in Acromyrmex gardens. Expression profiles of fungal enzymes in Atta also...... decomposition enzymes....

  13. Dicty_cDB: VHH618 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ATTA sequence update 2002.10.25 Translated Amino Acid sequence if*ppyfhthkiqininis...MKVLDTEIAKKLAGQSVTSAEFTPKQATLVKEY DI Translated Amino Acid sequence (All Frames) ...Frame A: if*ppyfhthkiqininisiifiyiyf*tlfflynnkifiylfnfnnnn*KMIEGSGSKT PKRNSDEISVKSLSIHEANTLSSEHEHESGNEELTLSQ

  14. Functional role of phenylacetic acid from metapleural gland secretions in controlling fungal pathogens in evolutionarily derived leaf-cutting ants

    OpenAIRE

    Fernández-Marín, Hermógenes; Nash, David R.; Higginbotham, Sarah; Estrada, Catalina; Jelle S van Zweden; D'Ettorre, Patrizia; Wcislo, William T.; Boomsma, Jacobus J.

    2015-01-01

    Fungus-farming ant colonies vary four to five orders of magnitude in size. They employ compounds from actinomycete bacteria and exocrine glands as antimicrobial agents. Atta colonies have millions of ants and are particularly relevant for understanding hygienic strategies as they have abandoned their ancestors' prime dependence on antibiotic-based biological control in favour of using metapleural gland (MG) chemical secretions. Atta MGs are unique in synthesizing large quantities of phenylace...

  15. Identificación de las feromonas de trilla de hormigas cortadoras (formicidae: attini1

    Directory of Open Access Journals (Sweden)

    Oscar Marino Mosquera

    2010-05-01

    Full Text Available Del extracto en diclorometano de las glándulas de veneno de las hormigas cortadoras: Atta laevigata, Atta bisphaerica, Acromyrmex subterraneus molestans. Fueron analizados por CG y CG-EM e identificados el 4-metilpirrol-2-carboxilato de metilo y el 3-etil-2,5-dimetilpirazina como los compuestos principales de la feromona de trilla (marcación de camino.

  16. TANGR2015 Heidelberg. Second international workshop on tracer applications of noble gas radionuclides in the geosciences

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-07-01

    TANGR2015 is a workshop on the progress in the technique and application of Atom Trap Trace Analyis (ATTA). It is a follow-up to the first TANGR workshop, TANGR2012, which was held at the Argonne National Laboratory, Argonne, USA, in June 2012. It is organized in response to recent technical advances and new applications of Atom Trap Trace Analysis (ATTA), an analytical method for measuring the isotopes {sup 81}Kr, {sup 85}Kr, and {sup 39}Ar. The primary aim of the workshop is to discuss the technical progress of ATTA and thereby enable innovative and timely applications of the noble gas radionuclides to important scientific problems in earth and environmental sciences, e.g. in the fields of groundwater hydrology, glaciology, oceanography, and paleoclimatology.

  17. TANGR2015 Heidelberg. Second international workshop on tracer applications of noble gas radionuclides in the geosciences

    International Nuclear Information System (INIS)

    TANGR2015 is a workshop on the progress in the technique and application of Atom Trap Trace Analyis (ATTA). It is a follow-up to the first TANGR workshop, TANGR2012, which was held at the Argonne National Laboratory, Argonne, USA, in June 2012. It is organized in response to recent technical advances and new applications of Atom Trap Trace Analysis (ATTA), an analytical method for measuring the isotopes 81Kr, 85Kr, and 39Ar. The primary aim of the workshop is to discuss the technical progress of ATTA and thereby enable innovative and timely applications of the noble gas radionuclides to important scientific problems in earth and environmental sciences, e.g. in the fields of groundwater hydrology, glaciology, oceanography, and paleoclimatology.

  18. A colony-level response to disease control in a leaf-cutting ant

    Science.gov (United States)

    Hart, Adam; Bot, A. N. M.; Brown, Mark

    2002-03-01

    Parasites and pathogens often impose significant costs on their hosts. This is particularly true for social organisms, where the genetic structure of groups and the accumulation of contaminated waste facilitate disease transmission. In response, hosts have evolved many mechanisms of defence against parasites. Here we present evidence that Atta colombica, a leaf-cutting ant, may combat Escovopsis, a dangerous parasite of Atta's garden fungus, through a colony-level behavioural response. In A. colombica, garden waste is removed from within the colony and transported to the midden - an external waste dump - where it is processed by a group of midden workers. We found that colonies infected with Escovopsis have higher numbers of workers on the midden, where Escovopsis is deposited. Further, midden workers are highly effective in dispersing newly deposited waste away from the dumping site. Thus, the colony-level task allocation strategies of the Atta superorganism may change in response to the threat of disease to a third, essential party.

  19. Differences in forage-acquisition and fungal enzyme activity contribute to niche segregation in Panamanian leaf-cutting ants.

    Directory of Open Access Journals (Sweden)

    Pepijn W Kooij

    Full Text Available The genera Atta and Acromyrmex are often grouped as leaf-cutting ants for pest management assessments and ecological surveys, although their mature colony sizes and foraging niches may differ substantially. Few studies have addressed such interspecific differences at the same site, which prompted us to conduct a comparative study across six sympatric leaf-cutting ant species in Central Panama. We show that foraging rates during the transition between dry and wet season differ about 60 fold between genera, but are relatively constant across species within genera. These differences appear to match overall differences in colony size, especially when Atta workers that return to their nests without leaves are assumed to carry liquid food. We confirm that Panamanian Atta specialize primarily on tree-leaves whereas Acromyrmex focus on collecting flowers and herbal leaves and that species within genera are similar in these overall foraging strategies. Species within genera tended to be spaced out over the three habitat categories that we distinguished (forest, forest edge, open grassland, but each of these habitats normally had only a single predominant Atta and Acromyrmex species. We measured activities of twelve fungus garden decomposition enzymes, belonging to the amylases, cellulases, hemicellulases, pectinases and proteinases, and show that average enzyme activity per unit of fungal mass in Atta gardens is lower than in Acromyrmex gardens. Expression profiles of fungal enzymes in Atta also appeared to be more specialized than in Acromyrmex, possibly reflecting variation in forage material. Our results suggest that species- and genus-level identities of leaf-cutting ants and habitat-specific foraging profiles may give predictable differences in the expression of fungal genes coding for decomposition enzymes.

  20. Differences in forage-acquisition and fungal enzyme activity contribute to niche segregation in Panamanian leaf-cutting ants.

    Science.gov (United States)

    Kooij, Pepijn W; Liberti, Joanito; Giampoudakis, Konstantinos; Schiøtt, Morten; Boomsma, Jacobus J

    2014-01-01

    The genera Atta and Acromyrmex are often grouped as leaf-cutting ants for pest management assessments and ecological surveys, although their mature colony sizes and foraging niches may differ substantially. Few studies have addressed such interspecific differences at the same site, which prompted us to conduct a comparative study across six sympatric leaf-cutting ant species in Central Panama. We show that foraging rates during the transition between dry and wet season differ about 60 fold between genera, but are relatively constant across species within genera. These differences appear to match overall differences in colony size, especially when Atta workers that return to their nests without leaves are assumed to carry liquid food. We confirm that Panamanian Atta specialize primarily on tree-leaves whereas Acromyrmex focus on collecting flowers and herbal leaves and that species within genera are similar in these overall foraging strategies. Species within genera tended to be spaced out over the three habitat categories that we distinguished (forest, forest edge, open grassland), but each of these habitats normally had only a single predominant Atta and Acromyrmex species. We measured activities of twelve fungus garden decomposition enzymes, belonging to the amylases, cellulases, hemicellulases, pectinases and proteinases, and show that average enzyme activity per unit of fungal mass in Atta gardens is lower than in Acromyrmex gardens. Expression profiles of fungal enzymes in Atta also appeared to be more specialized than in Acromyrmex, possibly reflecting variation in forage material. Our results suggest that species- and genus-level identities of leaf-cutting ants and habitat-specific foraging profiles may give predictable differences in the expression of fungal genes coding for decomposition enzymes. PMID:24718261

  1. An Evaluation of the Practicum Course of Pre-School Teacher Education Program in North Cyprus

    OpenAIRE

    ÖZDER, HASAN; Serdal IŞIKTAŞ; İSKİFOĞLU, Gökhan; ERDOĞAN, Fatoş

    2014-01-01

    The purpose of this study is to evaluate the practicum course of the pre-school teacher education programs across Atatürk Teacher Training Academy (ATTA) and Girne American University (GAU). The participants of this study were composed of senior level fourth grader pre-service teachers who were enrolled in the pre-school teacher education programs of ATTA and GAU during the 2012-2013 academic years. In the research, a curriculum assessment approach was implemented. This approach is based on p...

  2. Diploid male production in a leaf-cutting ant

    DEFF Research Database (Denmark)

    Armitage, S.; Boomsma, J.; Baer, Boris

    2010-01-01

    1. In haplodiploid social insects where males are haploid and females are diploid, inbreeding depression is expressed as the production of diploid males when homozygosity at the sex-determining locus results in the production of diploid individuals with a male phenotype. Diploid males are often...... success would be reduced compared with haploid males if they were able to copulate. 5. We conclude that diploid male production is likely to affect the fitness of A. sexdens queens with a matched mating, as these males are produced at the cost of workers and, if the colony survives to reach mature size...

  3. Automated analysis of security requirements through risk-based argumentation

    NARCIS (Netherlands)

    Yu, Yijun; Franqueira, Virginia N.L.; Tun, Thein Tan; Wieringa, Roel J.; Nuseibeh, Bashar

    2015-01-01

    Computer-based systems are increasingly being exposed to evolving security threats, which often reveal new vulnerabilities. A formal analysis of the evolving threats is difficult due to a number of practical considerations such as incomplete knowledge about the design, limited information about atta

  4. Assessment of crop growth and water productivity for five C3 species in semi-arid Inner Mongolia

    NARCIS (Netherlands)

    Yuan, M.; Zhang, L.; Gou, F.; Su, Z.; Spiertz, J.H.J.; Werf, van der W.

    2013-01-01

    Water availability is a key biophysical factor determining agricultural production potential. The FAO crop water response model AquaCrop was developed to estimate crop production under water limiting conditions. This model uses the normalized water productivity, WP* (g m-2 d-1), to estimate the atta

  5. Medium-dose riboflavin as a prophylactic agent in children with migraine: A preliminary placebo-controlled, randomised, double-blind, cross-over trial

    NARCIS (Netherlands)

    J.K.J. Bruijn (Jacques); H.J. Duivenvoorden (Hugo); J. Passchier (Jan); H. Locher (Heiko); N. Dijkstra (Natascha); W.F.M. Arts (Willem Frans)

    2010-01-01

    textabstractBackground: Riboflavin seems to have a promising effect on migraine in adults. The present study examines whether riboflavin has a prophylactic effect on migraine in children. Objective: To investigate whether riboflavin in a dosage of 50 mg/day has a prophylactic effect on migraine atta

  6. Contribution of image analysis to the detection of endolithic microbial communities in limestones used in cultural heritage.

    OpenAIRE

    Rogerio Candelera, Miguel A.; Miller, A. Z.; Sáiz-Jiménez, Cesáreo

    2009-01-01

    Terrestrial and aquatic environments are inhabited by phototrophic microorganisms that include cyanobacteria, green algae and diatoms. These microorganisms have a global significance in the deterioration of cultural heritage stone materials emphasized by their photoautotrophic nature, which permits them to be primary colonizers of lithobiontic ecological niche (Golubic et al. 1981). They develop forming phototrophic biofilms which can be described as surface atta...

  7. Thymidine Phosphorylase Inhibitors

    Czech Academy of Sciences Publication Activity Database

    Nencka, Radim

    Karachi : Bentham Science Publishers, 2011 - (Atta-ur-Rahman, F.; Choudhary, M.), s. 116-147 ISBN 978-1-60805-162-5 R&D Projects: GA MŠk 1M0508; GA AV ČR 1QS400550501 Institutional research plan: CEZ:AV0Z40550506 Keywords : thymidine phosphorylase inhibitors * angiogenesis * cancer chemotherapy Subject RIV: CC - Organic Chemistry

  8. ClEST cluster :Clmt_contig0003 [ClEST

    Lifescience Database Archive (English)

    Full Text Available C lmt_c ontig0003 c ytoc hrome c ... oxidase subunit iii mitoc hondrial gene 804 ATGAAAC AAGAC AAAAACC ACCC A ... TATC ATATAGTAGATTAC AGCCC TTGGCC TTTAAC TGGATC AATTGGAGC ATTAA C ATTAACC TTC GGAATAGTTATTTGATTTC ATAAAAAAGAAAGAATATTAATAATATT ... AGGAATAGTTATTATTATTTTAAC TATATTTC AATGATGAC GAGATATTATTC GAGAAAGAAC ATATC AAGGAC A ... TC ATAC ATTAAAAGTC GCC AAAGGAATTAAAATAGGAATAATC TTATTC ATTA ...

  9. Has substrate-dependent co-evolution of enzyme function occured in the attine ant-fungus symbiosis

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    The conspicuous leaf-cutter ants in the genus Atta build huge nests displacing several cubic meters of soil, whereas lower attine genera such as Cyphomyrmex have small nests with a fungus garden the size of a table-tennis ball. Only the leaf-cutter ants are specialized on using fresh leaves as...

  10. Los estados inmaduros de Coelosis biloba (Coleoptera: Melolonthidae: Dynastinae y notas sobre su biología Immature stages of Coelosis biloba (Coleoptera: Melolonthidae: Dynastinae with notes on their biology

    Directory of Open Access Journals (Sweden)

    Luis Carlos Pardo-Locarno

    2006-12-01

    Full Text Available Se describen la larva de tercer estadio y las pupas de macho y hembra de Coelosis biloba (Linné 1767 con ejemplares recolectados en Colombia (Cauca y Valle y en México (Veracruz asociados con los hormigueros de Atta cephalotes (Linné 1750. Se incluyen ilustraciones de las estructuras diagnósticas, una clave para separar las larvas de tercer estadio hasta ahora conocidas de la tribu Oryctini en América, y observaciones sobre la biología de C. biloba como inquilino de los nidos de hormigas.The larva of third instar, male and female pupae of Coelosis biloba obtained inside ant nests of Atta cephalotes in Colombia (Cauca, Valle and Mexico (Veracruz are described. Drawings of diagnostic structures, a key to the known third instar larvae of American Oryctini, and observations on the biology of C. biloba as inquiline of ant nests, are included.

  11. A New Method of Measuring 81Kr and 85Kr Abundances in Environmental Samples

    CERN Document Server

    Du, X; Bailey, K; Lehmann, B E; Lorenzo, R; Lu, Z T; Müller, P; O'Connor, T P; Sturchio, N C; Young, L

    2003-01-01

    We demonstrate a new method for determining the 81Kr/Kr ratio in environmental samples based upon two measurements: the 85Kr/81Kr ratio measured by Atom Trap Trace Analysis (ATTA) and the 85Kr/Kr ratio measured by Low-Level Counting (LLC). This method can be used to determine the mean residence time of groundwater in the range of 10^5 - 10^6 a. It requires a sample of 100 micro-l STP of Kr extracted from approximately two tons of water. With modern atmospheric Kr samples, we demonstrate that the ratios measured by ATTA and LLC are directly proportional to each other within the measurement error of +/- 10%; we calibrate the 81Kr/Kr ratio of modern air measured using this method; and we show that the 81Kr/Kr ratios of samples extracted from air before and after the development of the nuclear industry are identical within the measurement error.

  12. Laboratory for Radiokrypton Dating

    Science.gov (United States)

    Zappala, J. C.; Jiang, W.; Bailey, K. G.; Lu, Z. T.; Mueller, P.; O'Connor, T. P.

    2015-12-01

    Due to its simple production and transport in the terrestrial environment, 81Kr (half-life = 230,000 yr) is the ideal tracer for old water and ice with mean residence times in the range of 105-106 years, a range beyond the reach of 14C. 81Kr-dating is now available to the earth science community at large thanks to the development of an efficient and selective atom counter based on the Atom Trap Trace Analysis (ATTA) method. ATTA is a laser-based atom counting method where individual neutral atoms of the desired isotope are selectively captured by laser beams, and their fluorescence detected via a CCD camera. ATTA is unique among trace analysis techniques in that it is free of interferences from any other isotopes, isobars, atomic or molecular species. The ATTA instrument at Argonne's Laboratory for Radiokrypton Dating is capable of measuring both 81Kr/Kr and 85Kr/Kr ratios of environmental samples in the range of 10-14-10-10. For 81Kr-dating in the age range of 150 kyr - 1500 kyr, the required sample size is 5 micro-L STP of krypton gas, which can be extracted from approximately 100 kg of water or 40 kg of ice. For 85Kr/Kr analysis, the sample size can be smaller by an order of magnitude. We are continually developing the method towards higher counting efficiency, smaller sample sizes requirements, and higher sample throughput rates. In the past four years, we have performed radiokrypton analysis of over 150 groundwater and ice samples extracted by collaborators from all seven continents. Sample collection and purification was performed by groups including the University of Chicago, the University of Illinois at Chicago, the University of Bern, and the International Atomic Energy Agency. This work is supported by the U.S. DOE, Office of Nuclear Physics, under contract DE-AC02-06CH11357.

  13. Mandarin and mandarin hybrid genetic transformation for resistance to Candidatus Liberibacter asiaticus

    OpenAIRE

    Soriano, L; Tavano, E. C.R.; R. Harakava; MOURÃO FILHO F.A.A.; B.M.J. Mendes

    2014-01-01

    Brazil is one of the largest producers and exporters of citrus. Currently, Huanglongbing disease (HLB) associated to Candidatus Liberibacter asiaticus (CLas) is the main threat to the citrus industry. The aim of this work is to study the genetic transformation of mandarin/mandarin hybrid 'Thomas' (Citrus reticulata Blanco) and 'Fremont' (C. clementina hort. ex Tanaka x C. reticulata Blanco) with the gene that encodes an attacin antibacterial peptide (attA) driven by phloem-specific promoters....

  14. Patterns of diversity and abundance of fungus-growing ants (Formicidae: Attini) in areas of the Brazilian Cerrado Padrões de diversidade e abundância de formigas cultivadoras de fungo (Formicidade: Attini) em áreas do Cerrado Brasileiro

    OpenAIRE

    Heraldo L. Vasconcelos; Bruna B. Araújo; Antonio J. Mayhé-Nunes

    2008-01-01

    Fungus-growing ants (tribe Attini) are characteristic elements of the New World fauna. However, there is little information on the patterns of diversity, abundance, and distribution of attine species in their native ecosystems, especially for the so-called "lower" genera of the tribe. A survey of attine ant nests (excluding Atta Fabricus, 1804 and Acromyrmex Mayr, 1865) was conducted in a variety of savanna and forest habitats of the Cerrado biome near Uberlândia, Brazil. In total, 314 nests ...

  15. Attachment and Psychotherapy

    OpenAIRE

    McKay, J.M.

    2010-01-01

    The aim of this study was to explore the relationship between therapy outcome, the therapeutic alliance and both patient and therapist attachment styles. 14 therapists and 27 patients participated. 78.57% (n = 11) therapists and 29.63% (n = 8) patients were classified as securely attached by self-report measures. It was predicted that more patients of secure therapists would show clinically significant improvement as determined by CORE-OM scores. However, 21.05% of patients with a secure atta...

  16. DIAGNOSIS OF MALARIA BY MAGNETIC DEPOSITION MICROSCOPY

    OpenAIRE

    Zimmerman, Peter A.; Thomson, Jodi M.; Fujioka, Hisashi; Collins, William E.; Zborowski, Maciej

    2006-01-01

    Although malaria contributes to a significant public health burden, malaria diagnosis relies heavily on either non-specific clinical symptoms or blood smear microscopy methods developed in the 1930s. These approaches severely misrepresent the number of infected individuals and the reservoir of parasites in malaria-endemic communities and undermine efforts to control disease. Limitations of conventional microscopy-based diagnosis center on time required to examine slides, time required to atta...

  17. An Overview of Integrated Management of Leaf-Cutting Ants (Hymenoptera: Formicidae) in Brazilian Forest Plantations

    OpenAIRE

    Ronald Zanetti; José Cola Zanuncio; Juliana Cristina Santos; Willian Lucas Paiva da Silva; Genésio Tamara Ribeiro; Pedro Guilherme Lemes

    2014-01-01

    Brazilian forest producers have developed integrated management programs to increase the effectiveness of the control of leaf-cutting ants of the genera Atta and Acromyrmex. These measures reduced the costs and quantity of insecticides used in the plantations. Such integrated management programs are based on monitoring the ant nests, as well as the need and timing of the control methods. Chemical control employing baits is the most commonly used method, however, biological, mechanical and cul...

  18. Leaf-Cutter Ant Parasitoids: Current Knowledge

    OpenAIRE

    Patricia J. Folgarait

    2013-01-01

    This review updates and summarizes the current knowledge about the interaction of leaf-cutter ants and their parasitoids by providing comparable data for Acromyrmex and Atta ants. First, an overview of the relevant aspects of the biology and taxonomy of leaf cutters and of their parasitoids is provided. Second, I show the peculiarities of the parasitoids attacking behaviors towards their host as well as the responses or ant defenses against the phorids exhibited by their hosts. Third, I discu...

  19. HIERARCHICAL DESIGN BASED INTRUSION DETECTION SYSTEM FOR WIRELESS AD HOC SENSOR NETWORK

    OpenAIRE

    Mohammad Saiful Islam Mamun; A.F.M. Sultanul Kabir

    2010-01-01

    In recent years, wireless ad hoc sensor network becomes popular both in civil and military jobs.However, security is one of the significant challenges for sensor network because of their deploymentin open and unprotected environment. As cryptographic mechanism is not enough to protect sensornetwork from external attacks, intrusion detection system needs to be introduced. Though intrusionprevention mechanism is one of the major and efficient methods against attacks, but there might besome atta...

  20. A modified device for intraoral radiography to assess the distal osseous defects of mandibular second molar after impacted third molar surgery

    OpenAIRE

    Ana, Faria-Inocencio; Mercedes, Gallas-Torreira

    2011-01-01

    Purpose This article is to describe a modified device for intraoral radiography which was developed to obtain reproducible radiographic images for assessment of distal osseous defects of the mandibular second molar (2 Mm) after impacted third molar (3 Mm) surgery. Materials and Methods A commercial available alignment system for posterior region was modified by adding a reference gauge pin (millimetric) and threading a hollow acrylic cylinder at the ring of the radiographic positioner to atta...

  1. Discovery of Defense- and Neuropeptides in Social Ants by Genome-Mining

    OpenAIRE

    Gruber, Christian W.; Markus Muttenthaler

    2012-01-01

    Natural peptides of great number and diversity occur in all organisms, but analyzing their peptidome is often difficult. With natural product drug discovery in mind, we devised a genome-mining approach to identify defense- and neuropeptides in the genomes of social ants from Atta cephalotes (leaf-cutter ant), Camponotus floridanus (carpenter ant) and Harpegnathos saltator (basal genus). Numerous peptide-encoding genes of defense peptides, in particular defensins, and neuropeptides or regulato...

  2. New insights into the reaction of Schistosoma mansoni cercaria to the human complement system

    OpenAIRE

    Da'dara, Akram A.; KRAUTZ-PETERSON, GREICE

    2014-01-01

    Schistosomes are parasitic worms that have a complex life cycle. The larval stage cercaria, infectious to mammals, is described as highly susceptible to the complement system, largely due to the glycocalyx that covers the cercarial membrane. In an attempt to have a more complete understanding of cercaria reaction to the complement system, three different approaches were used. Live cercariae exposed to normal human serum (NHS) as source of complement factors were assessed for: i) Membrane Atta...

  3. Menjajaki Kemungkinan Islamisasi Sosiologi Pengetahuan

    OpenAIRE

    Muhammad Imdad

    2015-01-01

    In the discussion of epistemology, the study of objectivity led to the disciplines of sociology. The principal thesis of the sociology is that there are modes of thought which cannot be adequately understood as long as their social origins are obscure. In its association with the project of Islamization of contemporary knowledge initiated by Syed Muhammad Naquib al-Attas, sociology turns out supporting one of the basic assumptions of this project; whereas science has their own value (value la...

  4. Genetic and Environmental Transactions Underlying Educational Attainment

    OpenAIRE

    Johnson, Wendy; Deary, Ian J.; IACONO, WILLIAM G.

    2009-01-01

    This report used a population-representative longitudinal twin study with two birth cohorts to explore the association between intelligence and education by understanding how genetic and environmental influences on intelligence moderate genetic and environmental influences on school grades and educational attainment. Non-shared environmental influences on grades were strong when IQ was low, but decreased across the range of IQ. Shared environmental influences common to age 24 educational atta...

  5. A GENERAL APPROACH TO VALUING COMMODITY-LINKED BONDS

    OpenAIRE

    Jin, Yufei; Turvey, Calum G.

    2004-01-01

    The purpose of this paper is to develop a general approach to valuing commodity-linked bonds (CLBs) based on the Heath-Jarrow-Morton (HJM) framework. The model deals with four dimensions of uncertainty: prices of the underlying commodity, the value of firm that issues bonds, interest rates, and convenience yields. A mathematical formula for the price of a commodity-linked bond is derived. The previous results in Black and Scholes (1973), Merton (1973), Schwartz (1982), and Atta-Mensah (1992) ...

  6. PERCEPTIONS OF WARMTH & COMPETENCE IN ONLINE NETWORKING: AN EXPERIMENTAL ANALYSIS OF A COMPANY LAUNCH

    OpenAIRE

    Andrei, Andreia Gabriela; Adriana ZAIŢ

    2014-01-01

    Our interdisciplinary research examines consumer perceptions and behavioral tendencies generated by these perceptions. The study is placed in the context of online networking and it uses marketing, branding and psychology literature, especially the theory of warmth and competence from social cognition and Aaker et al.'s research results about firm stereotyping: 'for-profits' as high in competence vs. 'non-profits' as high in warmth. We used an experimental approach to investigate ways to atta...

  7. Gene : CBRC-RMAC-03-0051 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-RMAC-03-0051 3 A Opsins OPSB_PANTR 0.0 96% ref|XP_001091869.1| PREDICTED: opsin 1 (cone pig ... ments), short-wave-sensitive (color ... blindness, tritan) [Macaca mulatta] 0.0 100% gnl|U ... atta opsin 1 (cone pigments), long-wave-sensitive (color ... blindness, protan) (OPN1LW), mRNA /gb=XR_010866 /g ...

  8. Evolution of cold-tolerant fungal symbionts permits winter fungiculture by leafcutter ants at the northern frontier of a tropical ant–fungus symbiosis

    OpenAIRE

    Mueller, Ulrich G.; Mikheyev, Alexander S.; Hong, Eunki; Sen, Ruchira; Warren, Dan L.; Solomon, Scott E.; Ishak, Heather D.; Cooper, Mike; Miller, Jessica L.; Shaffer, Kimberly A.; Juenger, Thomas E.

    2011-01-01

    The obligate mutualism between leafcutter ants and their Attamyces fungi originated 8 to 12 million years ago in the tropics, but extends today also into temperate regions in South and North America. The northernmost leafcutter ant Atta texana sustains fungiculture during winter temperatures that would harm the cold-sensitive Attamyces cultivars of tropical leafcutter ants. Cold-tolerance of Attamyces cultivars increases with winter harshness along a south-to-north temperature gradient across...

  9. The Political Paradox of Finance Capitalism: Interests, Preferences, and Center-Left Party Politics in Corporate Governance Reform

    OpenAIRE

    Cioffi, J.; Höpner, M.

    2006-01-01

    A striking paradox underlies corporate governance reform during the past fifteen years: center-left political parties have pushed for pro-shareholder corporate governance reforms, while the historically pro-business right has generally resisted them to protect established forms of organized capitalism, concentrated corporate stock ownership, and managerialism. Case studies of Germany, France, Italy, and the United States reveal that center-left parties used corporate governance reform to atta...

  10. Progressive Collapse Analysis of Two Existing Steel Buildings Using Linear Static Procedure

    OpenAIRE

    Larijani, Reza Jalali

    2012-01-01

    ABSTRACT: There are numerous threats which could cause progressive collapse in a structure that may lead to fatality. After the incident in Oklahoma Murrah building and the recent terrorist attacks, such as WTC (World Trade Center) in 2001, it became more important to do assessment towards preventing the progressive collapse. Although, there have been many researches carried out on progressive collapse, the increase in terrorist attacks, especially loss of lives (nearly 3000 died in the atta...

  11. Sequential Soil Transport and Its Influence on the Spatial Organisation of Collective Digging in Leaf-Cutting Ants

    OpenAIRE

    Steffen Pielström; Flavio Roces

    2013-01-01

    The Chaco leaf-cutting ant Atta vollenweideri (Forel) inhabits large and deep subterranean nests composed of a large number of fungus and refuse chambers. The ants dispose of the excavated soil by forming small pellets that are carried to the surface. For ants in general, the organisation of underground soil transport during nest building remains completely unknown. In the laboratory, we investigated how soil pellets are formed and transported, and whether their occurrence influences the spat...

  12. Development and Validation of a Simulator based on a First-Principle Flotation Model

    OpenAIRE

    Soni, Gaurav

    2013-01-01

    A first-principle flotation model was derived at Virginia Tech from the basic mechanisms involved in the bubble-particle and bubble-bubble interactions occurring in a flotation cell (Yoon and Mao, 1996; Sherrell and Yoon, 2005; Do, H, 2010). The model consists of a series of analytical equations for bubble generation, bubble-particle collision, attachment, detachment, and froth phase recovery. The process of bubble-particle attachment has been modelled on the premise that bubble-particle atta...

  13. Attachment of Giardia lamblia trophozoites to a cultured human intestinal cell line.

    OpenAIRE

    Katelaris, P H; Naeem, A; Farthing, M J

    1995-01-01

    Attachment of Giardia lamblia trophozoites to enterocytes is essential for colonisation of the small intestine and is considered a prerequisite for giardia induced enterocyte damage. The precise mechanisms involved are still being debated and some earlier work has been performed in models of uncertain biological relevance. In this study, co-incubation of giardia with enterocyte-like differentiated Caco-2 cells was used as a model to study the influence of physical and chemical factors on atta...

  14. Differences in Forage-Acquisition and Fungal Enzyme Activity Contribute to Niche Segregation in Panamanian Leaf-Cutting Ants

    OpenAIRE

    Kooij, Pepijn W.; Joanito Liberti; Konstantinos Giampoudakis; Morten Schiøtt; Boomsma, Jacobus J.

    2014-01-01

    The genera Atta and Acromyrmex are often grouped as leaf-cutting ants for pest management assessments and ecological surveys, although their mature colony sizes and foraging niches may differ substantially. Few studies have addressed such interspecific differences at the same site, which prompted us to conduct a comparative study across six sympatric leaf- cutting ant species in Central Panama. We show that foraging rates during the transition between dry and wet season differ about 60 fold b...

  15. An Examination of the Critical Factors of Store Brand Purchase Intentions

    OpenAIRE

    Zhao, XiaoQian

    2011-01-01

    Consumer behaviour is very complex interaction of affect, cognition, behaviour and environment activities, which deals with how and why individuals conduct the exchange events of products and service. Brand, as a signal of quality assurance and sometimes a symbol of identity, plays a significant role in consumer decision making process. Thus build up brand assets and improve brand equity is important in brand management. As a main source of consumer packaged goods, store brands should be atta...

  16. Non-Mulberry and Mulberry Silk Protein Sericins as Potential Media Supplement for Animal Cell Culture

    OpenAIRE

    Sahu, Neety; Pal, Shilpa; Sapru, Sunaina; Kundu, Joydip; Talukdar, Sarmistha; Singh, N. Ibotambi; Yao, Juming; Kundu, Subhas C.

    2016-01-01

    Silk protein sericins, in the recent years, find application in cosmetics and pharmaceuticals and as biomaterials. We investigate the potential of sericin, extracted from both mulberry Bombyx mori and different non-mulberry sources, namely, tropical tasar, Antheraea mylitta; muga, Antheraea assama; and eri, Samia ricini, as growth supplement in serum-free culture medium. Sericin supplemented media containing different concentrations of sericins from the different species are examined for atta...

  17. Values Following a Major Terrorist Incident: Finnish Adolescent and Student Values Before and After September 11, 2001

    OpenAIRE

    Goodwin, R; Verkasalo, M.; Bezmenova, I

    2006-01-01

    The horrific terrorist attacks on the United States on September 11, 2001, left an indelible mark on perceptions of security and threat across the world. This paper uses Schwartz’s (1992) value circumplex model to examine value change across matched high school and university student samples in Finland, questioned before and after the World Trade Center (WTC) and associated attacks. In Study 1 (N5419), security values of adolescents were higher the day following the WTC atta...

  18. Generation of Nutrients and Detoxification: Possible Roles of Yeasts in Leaf-Cutting Ant Nests

    OpenAIRE

    Pagnocca, Fernando C.; Ifeloju Dayo-Owoyemi; Marson, Fernando A L; Mendes, Thais D.; André Rodrigues

    2012-01-01

    The possible roles played by yeasts in attine ant nests are mostly unknown. Here we present our investigations on the plant polysaccharide degradation profile of 82 yeasts isolated from fungus gardens of Atta and Acromyrmex species to demonstrate that yeasts found in ant nests may play the role of making nutrients readily available throughout the garden and detoxification of compounds that may be deleterious to the ants and their fungal cultivar. Among the yeasts screened, 65% exhibited cellu...

  19. Dual MMP7-Proximity-Activated and Folate Receptor-Targeted Nanoparticles for siRNA Delivery

    OpenAIRE

    Li, Hongmei; Miteva, Martina; Kirkbride, Kellye C; Cheng, Ming J.; Nelson, Christopher E.; Elaine M Simpson; Gupta, Mukesh K; Duvall, Craig L.; Giorgio, Todd D.

    2014-01-01

    A dual-targeted siRNA nanocarrier has been synthesized and validated that is selectively activated in environments where there is colocalization of two breast cancer hallmarks, elevated matrix metalloproteinase (MMP) activity and folate receptor overexpression. This siRNA nanocarrier is self-assembled from two polymers containing the same pH-responsive, endosomolytic core-forming block but varying hydrophilic, corona-forming blocks. The corona block of one polymer consists of a 2 kDa PEG atta...

  20. Belgium, Canada and Switzerland: are there differences in the contributions of selected variables on self-reported property-related and violent delinquency?

    OpenAIRE

    Egli, Nicole; Vettenburg, Nicole; Savoie, Josée; Lucia, Sonia

    2010-01-01

    Three countries with different sociodemographic characteristics and different school and criminal justice systems are compared using data from Belgium, Switzerland, and Canada with respect to juvenile delinquency as measured by the International Self-Reported Delinquency questionnaire (ISRD-2). Following a brief presentation of descriptive statistics of the different samples, multivariate analyses including basic variables such as gender, age, family composition, immigrant status, school atta...

  1. Improving existing computer codes by interactive computer graphics: HAREA: an interactive program to derive resonance parameters by area analysis of neutron transmission data

    International Nuclear Information System (INIS)

    An arrangement of programs is described providing interactive computer graphics assistance to improve the operation of an existing fitting program. The particular example is the well-known 'Atta-Harvey' code used in resonance area analysis of neutron transmission data. This report is intended both as a manual for running the area analysis programs and as a practical example of program improvement by interactive programming methods. (U.K.)

  2. Dramatic intraspecific differences in migratory routes, stopover sites and wintering areas, revealed using light-level geolocators

    OpenAIRE

    Delmore, Kira E.; Fox, James W.; Irwin, Darren E

    2012-01-01

    Migratory divides are contact zones between breeding populations that use divergent migratory routes and have been described in a variety of species. These divides are of major importance to evolution, ecology and conservation but have been identified using limited band recovery data and/or indirect methods. Data from band recoveries and mitochondrial haplotypes suggested that inland and coastal Swainson's thrushes (Catharus ustulatus) form a migratory divide in western North America. We atta...

  3. Treatment Resistant Bipolar Disorder

    OpenAIRE

    Elvan Ozalp; Ersin Hatice Karslioglu

    2015-01-01

    Many patients diagnosed with bipolar disorder respond incompletely or unsatisfactorily to available treatments. Defining refractoriness in bipolar disorder is a complex issue and should concern and include either every phase and pole or the disorder as a whole. There are only limited and sometimes confusing data on the treatment of refractory bipolar patients. The objective of this paper was to review the evidence for treatment options in treatment resistant patients on depressive, manic atta...

  4. Kidney function and mortality post-liver transplant in the Model for End-Stage Liver Disease era

    OpenAIRE

    Sethi A; Estrella MM; Ugarte R; Atta MG

    2011-01-01

    Aastha Sethi1, Michelle M Estrella1, Richard Ugarte2, Mohamed G Atta1 1Johns Hopkins University School of Medicine, Department of Medicine, Baltimore, MD, USA; 2University of Maryland Medical Center, Department of Medicine, Baltimore, MD, USA Abstract: The Model for End-Stage Liver Disease (MELD) score incorporates serum creatinine and was introduced to facilitate allocation of orthotopic liver transplantation (LT). The objective is to determine the impact of MELD and kidney function on all-...

  5. The use of alarm pheromones to enhance bait harvest by grass-cutting ants.

    Science.gov (United States)

    Hughes, W O H; Goulson, D

    2002-06-01

    The enhancement of bait for the control of grass-cutting ants was investigated using two species of grass-cutting ant, Atta bisphaerica (Forel) and Atta capiguara (Gonçalves) (Hymenoptera: Formicidae). Bait was applied in loose piles to obtain a direct relationship between ant attraction and bait harvest. Enhancement with alarm pheromone compounds significantly increased the attractiveness and harvest of bait under certain conditions. A large proportion of the ants attracted to the enhanced bait were minor workers. These ants rarely transport bait because of their small size, and so it may be possible to increase the effect of bait enhancement by using smaller bait granules. Foragers of A. capiguara were less inclined to transport citrus-pulp bait than were those of Atta laevigata (Fr. Smith), a species that also harvests dicotyledonous plants. This emphasizes the importance of developing a bait matrix that is more acceptable to grass-cutting species. Nevertheless, the results suggest that alarm pheromone compounds have significant potential to improve the efficacy of baits for the control of grass-cutting ants. PMID:12088538

  6. Functional role of phenylacetic acid from metapleural gland secretions in controlling fungal pathogens in evolutionarily derived leaf-cutting ants.

    Science.gov (United States)

    Fernández-Marín, Hermógenes; Nash, David R; Higginbotham, Sarah; Estrada, Catalina; van Zweden, Jelle S; d'Ettorre, Patrizia; Wcislo, William T; Boomsma, Jacobus J

    2015-05-22

    Fungus-farming ant colonies vary four to five orders of magnitude in size. They employ compounds from actinomycete bacteria and exocrine glands as antimicrobial agents. Atta colonies have millions of ants and are particularly relevant for understanding hygienic strategies as they have abandoned their ancestors' prime dependence on antibiotic-based biological control in favour of using metapleural gland (MG) chemical secretions. Atta MGs are unique in synthesizing large quantities of phenylacetic acid (PAA), a known but little investigated antimicrobial agent. We show that particularly the smallest workers greatly reduce germination rates of Escovopsis and Metarhizium spores after actively applying PAA to experimental infection targets in garden fragments and transferring the spores to the ants' infrabuccal cavities. In vitro assays further indicated that Escovopsis strains isolated from evolutionarily derived leaf-cutting ants are less sensitive to PAA than strains from phylogenetically more basal fungus-farming ants, consistent with the dynamics of an evolutionary arms race between virulence and control for Escovopsis, but not Metarhizium. Atta ants form larger colonies with more extreme caste differentiation relative to other attines, in societies characterized by an almost complete absence of reproductive conflicts. We hypothesize that these changes are associated with unique evolutionary innovations in chemical pest management that appear robust against selection pressure for resistance by specialized mycopathogens. PMID:25925100

  7. Grain size stabilization of nanocrystalline copper at high temperatures by alloying with tantalum

    International Nuclear Information System (INIS)

    Highlights: •A mean grain size of 167 nm is retained after annealing at 97% of the melting point. •Hardness surpasses conventional pure nanocrystalline Cu by 2.5 GPa. •Extreme stability is attributed to both thermodynamic and kinetic stabilization. -- Abstract: Nanocrystalline Cu–Ta alloys belong to an emerging class of immiscible materials with potential for high-temperature applications. Differential scanning calorimetry (DSC), Vickers microhardness, transmission and scanning electron microscopy (TEM/SEM), and atomistic simulations have been applied to study the structural evolution in high-energy cryogenically alloyed nanocrystalline Cu–10 at.%Ta. The thermally induced coarsening of the as-milled microstructure was investigated and it was found that the onset of grain growth occurs at temperatures higher than that for pure nanocrystalline Cu. The total heat release associated with grain growth was 0.553 kJ/mol. Interestingly, nanocrystalline Cu–10 at.%Ta maintains a mean grain size (GS) of 167 nm after annealing at 97% of its melting point. The increased microstructural stability is attributed to a combination of thermodynamic and kinetic stabilization effects which, in turn, appear to be controlled by segregation and diffusion of Ta solute atoms along grain boundaries (GBs). The as-milled nanocrystalline Cu–10 at.%Ta exhibits Vickers microhardness values near 5 GPa surpassing the microhardness of conventional pure nanocrystalline Cu by ∼2.5 GPa

  8. Tracer Applications of Noble Gas Radionuclides in the Geosciences

    CERN Document Server

    Lu, Z -T; Smethie, W M; Sturchio, N C; Fischer, T P; Kennedy, B M; Purtschert, R; Severinghaus, J P; Solomon, D K; Tanhua, T; Yokochi, R

    2013-01-01

    The noble gas radionuclides, including 81Kr (half-life = 229,000 yr), 85Kr (11 yr), and 39Ar (269 yr), possess nearly ideal chemical and physical properties for studies of earth and environmental processes. Recent advances in Atom Trap Trace Analysis (ATTA), a laser-based atom counting method, have enabled routine measurements of the radiokrypton isotopes, as well as the demonstration of the ability to measure 39Ar in environmental samples. Here we provide an overview of the ATTA technique, and a survey of recent progress made in several laboratories worldwide. We review the application of noble gas radionuclides in the geosciences and discuss how ATTA can help advance these fields, specifically determination of groundwater residence times using 81Kr, 85Kr, and 39Ar; dating old glacial ice using 81Kr; and an 39Ar survey of the main water masses of the oceans, to study circulation pathways and estimate mean residence times. Other scientific questions involving deeper circulation of fluids in the Earth's crust ...

  9. Metagenomic and metaproteomic insights into bacterial communities in leaf-cutter ant fungus gardens

    Energy Technology Data Exchange (ETDEWEB)

    Aylward, Frank O.; Burnum, Kristin E.; Scott, Jarrod J.; Suen, Garret; Tringe, Susannah G.; Adams, Sandra M.; Barry, Kerrie W.; Nicora, Carrie D.; Piehowski, Paul D.; Purvine, Samuel O.; Starrett, Gabriel J.; Goodwin, Lynne A.; Smith, Richard D.; Lipton, Mary S.; Currie, Cameron R.

    2012-09-01

    Herbivores gain access to nutrients stored in plant biomass largely by harnessing the metabolic activities of microbes. Leaf-cutter ants of the genus Atta are a hallmark example; these dominant Neotropical herbivores cultivate symbiotic fungus gardens on massive quantities of fresh plant forage. As the external digestive system of the ants, fungus gardens facilitate the production and sustenance of millions of workers in mature Atta colonies. Here we use metagenomic, and metaproteomic techniques to characterize the bacterial diversity and overall physiological potential of fungus gardens from two species of Atta. Our analysis of over 1.2 Gbp of community metagenomic sequence and three 16S pyrotag libraries reveals that, in addition to harboring the dominant fungal crop, these ecosystems contain abundant populations of Enterobacteriaceae, including the genera Enterobacter, Pantoea, Klebsiella, Citrobacter, and Escherichia. We show that these bacterial communities possess genes commonly associated with lignocellulose degradation, and likely participate in the processing of plant biomass. Additionally, we demonstrate that bacteria in these environments encode a diverse suite of biosynthetic pathways, and that they may enrich the nitrogen-poor forage of the ants with B-vitamins, amino acids, and proteins. These results are consistent with the hypothesis that fungus gardens are highly-specialized fungus-bacteria communities that efficiently convert plant material into usable energy for their ant hosts. Together with recent investigations into the microbial symbionts of vertebrates, our work underscores the importance of microbial communities to the ecology and evolution of herbivorous metazoans.

  10. Extended-Range Passive RFID and Sensor Tags

    Science.gov (United States)

    Fink, Patrick W.; Kennedy, Timothy F.; Lin, Gregory Y.; Barton, Richard

    2012-01-01

    Extended-range passive radio-frequency identification (RFID) tags and related sensor tags are undergoing development. A tag of this type incorporates a retroreflective antenna array, so that it reflects significantly more signal power back toward an interrogating radio transceiver than does a comparable passive RFID tag of prior design, which does not incorporate a retroreflective antenna array. Therefore, for a given amount of power radiated by the transmitter in the interrogating transceiver, a tag of this type can be interrogated at a distance greater than that of the comparable passive RFID or sensor tag of prior design. The retroreflective antenna array is, more specifically, a Van Atta array, named after its inventor and first published in a patent issued in 1959. In its simplest form, a Van Atta array comprises two antenna elements connected by a transmission line so that the signal received by each antenna element is reradiated by the other antenna element (see Figure 1). The phase relationships among the received and reradiated signals are such as to produce constructive interference of the reradiated signals; that is, to concentrate the reradiated signal power in a direction back toward the source. Hence, an RFID tag equipped with a Van Atta antenna array automatically tracks the interrogating transceiver. The effective gain of a Van Atta array is the same as that of a traditional phased antenna array having the same number of antenna elements. Additional pairs of antenna elements connected by equal-length transmission lines can be incorporated into a Van Atta array to increase its directionality. Like some RFID tags here-to-fore commercially available, an RFID or sensor tag of the present developmental type includes one-port surface-acoustic-wave (SAW) devices. In simplified terms, the mode of operation of a basic one-port SAW device as used heretofore in an RFID device is the following: An interrogating radio signal is converted, at an input end, from

  11. Monoculture of leafcutter ant gardens.

    Directory of Open Access Journals (Sweden)

    Ulrich G Mueller

    Full Text Available BACKGROUND: Leafcutter ants depend on the cultivation of symbiotic Attamyces fungi for food, which are thought to be grown by the ants in single-strain, clonal monoculture throughout the hundreds to thousands of gardens within a leafcutter nest. Monoculture eliminates cultivar-cultivar competition that would select for competitive fungal traits that are detrimental to the ants, whereas polyculture of several fungi could increase nutritional diversity and disease resistance of genetically variable gardens. METHODOLOGY/PRINCIPAL FINDINGS: Using three experimental approaches, we assessed cultivar diversity within nests of Atta leafcutter ants, which are most likely among all fungus-growing ants to cultivate distinct cultivar genotypes per nest because of the nests' enormous sizes (up to 5000 gardens and extended lifespans (10-20 years. In Atta texana and in A. cephalotes, we resampled nests over a 5-year period to test for persistence of resident cultivar genotypes within each nest, and we tested for genetic differences between fungi from different nest sectors accessed through excavation. In A. texana, we also determined the number of Attamyces cells carried as a starter inoculum by a dispersing queens (minimally several thousand Attamyces cells, and we tested for genetic differences between Attamyces carried by sister queens dispersing from the same nest. Except for mutational variation arising during clonal Attamyces propagation, DNA fingerprinting revealed no evidence for fungal polyculture and no genotype turnover during the 5-year surveys. CONCLUSIONS/SIGNIFICANCE: Atta leafcutter ants can achieve stable, fungal monoculture over many years. Mutational variation emerging within an Attamyces monoculture could provide genetic diversity for symbiont choice (gardening biases of the ants favoring specific mutational variants, an analog of artificial selection.

  12. Effect of migraine attacks on paracetamol absorption.

    OpenAIRE

    Tokola, R A; Neuvonen, P J

    1984-01-01

    The absorption of effervescent paracetamol (1000 mg) was investigated in nine female patients during a migraine attack and in the same patients when headache free. Migraine attack decreased (P less than 0.05) the areas under the serum paracetamol concentration-time curves (AUC) of 0-2 h, 0-4 h and 0-6 h and the peak serum concentration. The severity of nausea correlated significantly with the decrease in the AUC values. Our results support findings of delayed gastric emptying in migraine atta...

  13. Possibilities to use retrodirective antennas in radar systems

    Directory of Open Access Journals (Sweden)

    Aleksandar M. Pavić

    2012-04-01

    Full Text Available Possibilities to use retrodirective antennas in modern radar systems are presented in this paper. The basics of retrodirective theory, practical realizations of retrodirective arrays using corner reflectors, Van-Atta and heterodyne elements are considered. A model of a retrodirective radar for automatic target tracking is presented as well as the differences between commonly used phase arrays and retrodirective arrays with simpler, cheaper signal processors and faster target detection, as mayor advantages of this technology. Its advantages and disadvantages are explained. In the end, some possibilities for this technology application are discussed as well as further research trends.

  14. Cartography past, present and future

    CERN Document Server

    Rhind, DW

    2013-01-01

    Making maps dates back at least four thousand years and it is widely recognised that many maps are of great historical value and present a skilled method of summarising the real world on a sheet of paper. Less well known is the judgement involved in the selection and simplification of features, the complex transformation of space and the exacting standards which are needed in cartography. This book is primarily a tribute to Professor F.J. Ormeling, former President and Secretary/Treasurer of the ICA and gives a wide ranging review of the current status of cartography, how this status was atta

  15. Solubility enhancement of simvastatin by arginine: thermodynamics, solute–solvent interactions, and spectral analysis

    OpenAIRE

    Meor Mohd Affandi MMR; Tripathy M; Shah SAA; Majeed ABA

    2016-01-01

    MMR Meor Mohd Affandi,1,2 Minaketan Tripathy,1,3 Syed Adnan Ali Shah,3,4 ABA Majeed1,3 1Laboratory of Fundamental Pharmaceutics, Faculty of Pharmacy, Universiti Teknologi MARA (UiTM), Bandar Puncak Alam, Selangor, Malaysia; 2DDH Core, Universiti Teknologi MARA (UiTM), Shah Alam, Selangor Darul Ehsan, Malaysia; 3Pharmaceutical and Life Sciences Core, Universiti Teknologi MARA (UiTM), Shah Alam, Selangor Darul Ehsan, Malaysia; 4Atta-ur-Rahman Institute for Natural Products Discovery (AuRIns), ...

  16. An Overview of Integrated Management of Leaf-Cutting Ants (Hymenoptera: Formicidae in Brazilian Forest Plantations

    Directory of Open Access Journals (Sweden)

    Ronald Zanetti

    2014-03-01

    Full Text Available Brazilian forest producers have developed integrated management programs to increase the effectiveness of the control of leaf-cutting ants of the genera Atta and Acromyrmex. These measures reduced the costs and quantity of insecticides used in the plantations. Such integrated management programs are based on monitoring the ant nests, as well as the need and timing of the control methods. Chemical control employing baits is the most commonly used method, however, biological, mechanical and cultural control methods, besides plant resistance, can reduce the quantity of chemicals applied in the plantations.

  17. Dinâmica populacional e ecologia do forrageamento de Acromyrmex Mayr, 1865 (hymenoptera: Formicidae)

    OpenAIRE

    Nickele, Mariane Aparecida

    2013-01-01

    Resumo: A tribo Attini (Hymenoptera: Formicidae) compreende 14 gêneros de formigas que estão envolvidas em um mutualismo obrigatório com fungos. As formigas cortadeiras, Atta e Acromyrmex, são consideradas as principais pragas de florestas plantadas de Pinus e Eucalyptus, no entanto, na região sul do Brasil, as espécies de Acromyrmex são mais comuns. O objetivo geral deste estudo foi avaliar a dinâmica populacional de formigas cortadeiras do gênero Acromyrmex em plantios de Pinus taeda e estu...

  18. Extended Range Passive Wireless Tag System and Method

    Science.gov (United States)

    Fink, Patrick W. (Inventor); Kennedy, Timothy F. (Inventor); Lin, Gregory Y. (Inventor)

    2013-01-01

    A passive wireless tag assembly comprises a plurality of antennas and transmission lines interconnected with circuitry and constructed and arranged in a Van Atta array or configuration to reflect an interrogator signal in the direction from where it came. The circuitry may comprise at least one surface acoustic wave (SAW)-based circuit that functions as a signal reflector and is operatively connected with an information circuit. In another embodiment, at least one delay circuit and/or at least one passive modulation circuit(s) are utilized. In yet another embodiment, antennas connected to SAW-based devices are mounted to at least one of the orthogonal surfaces of a corner reflector.

  19. Effects of Protein Kinase C on the L-Type Ca2+ Channel in Single Rabbit Sino-Atrial Nodal Cells : Analysis by Patch-Clamp Technique

    OpenAIRE

    Satoh, Hiroyasu; 佐藤, 広康

    1994-01-01

    Efects of phorbol esters (stimulator of protein kinase C) on the L-type Ca^2+ current in isolated single rabbit sino-atrial (SA) nodal cells were examined. In whole-cell voltage-clamp experiments, 12-0-tetradecanoylphorbo1-13-acetate (TPA) at 10^-7 M inhibited the L-type Ca^2+ current. Pretreatment with H-7 (10^-5 M), an antagonist of protein kinase C (PK-C), did not modify the TPA-induced depression. The time course of inactivation process for the L-type Ca^2 current was slowed. In cell-atta...

  20. Education and research aimed to public health outcomes: strategies to fight the lack of nourishment in Colombia

    Directory of Open Access Journals (Sweden)

    Edwar Javier Manrique Corredor

    2013-12-01

    Full Text Available The following article provides an overview of the nutritional status of children in Colombia, and the implications it has on the economic, social, cultural and political development; addresses two strategies that allow from the Primary Health Care more understanding of malnutrition and household food insecurity in Colombia: the health Education and health Outcomes Research, recently discussed and developed strategies in political and health of Colombia, which has also led to a misapplication of primary care, focusing their best efforts on hospital care and leaving aside the levels of prevention, health promotion and participation as stated in Alma Atta in 1978.

  1. PSO Based Optimized Security Scheme for Image Authentication and Tamper Proofing

    Directory of Open Access Journals (Sweden)

    K. Kuppusamy

    2013-05-01

    Full Text Available The hash function offers an authentication and an i ntegrity to digital images. In this paper an innovative optimized security scheme based on Parti cle swarm optimization (PSO for image authentication and tamper proofing is proposed. Thi s scheme provide solutions to the issues such as robustness, security and tamper detection with precise localization. The features are extracted in Daubechies4 wavelet transform domain w ith help of PSO to generate the image hash. This scheme is moderately robust against atta cks and to detect and locate the tampered areas in an image. The experimental results are pre sented to exhibit the effectiveness of the proposed scheme.

  2. Functional role of phenylacetic acid from metapleural gland secretions in controlling fungal pathogens in evolutionarily derived leaf-cutting ants

    DEFF Research Database (Denmark)

    Fernández-Marín, Hermógenes; Nash, David Richard; Higginbotham, Sarah;

    2015-01-01

    derived leaf-cutting ants are less sensitive to PAA than strains from phylogenetically more basal fungus-farming ants, consistent with the dynamics of an evolutionary arms race between virulence and control for Escovopsis, but not Metarhizium. Atta ants form larger colonies with more extreme caste...... differentiation relative to other attines, in societies characterized by an almost complete absence of reproductive conflicts.We hypothesize that these changes are associatedwith unique evolutionary innovations in chemical pest management that appear robust against selection pressure for resistance by specialized...

  3. Development of Genome-wide Simple Sequence Repeat Markers Using Whole-genome Shotgun Sequences of Sorghum (Sorghum bicolor (L.) Moench)

    OpenAIRE

    Yonemaru, Jun-ichi; Ando, Tsuyu; Mizubayashi, Tatsumi; Kasuga, Shigemitsu; Matsumoto, Takashi; Yano, Masahiro

    2009-01-01

    Simple sequence repeat (SSR) markers with a high degree of polymorphism contribute to the molecular dissection of agriculturally important traits in sorghum (Sorghum bicolor (L.) Moench). We designed 5599 non-redundant SSR markers, including regions flanking the SSRs, in whole-genome shotgun sequences of sorghum line ATx623. (AT/TA) n repeats constituted 26.1% of all SSRs, followed by (AG/TC) n at 20.5%, (AC/TG) n at 13.7% and (CG/GC) n at 11.8%. The chromosomal locations of 5012 SSR markers ...

  4. Leafcutter Ant Nests Inhibit Low-Intensity Fire Spread in the Understory of Transitional Forests at the Amazon's Forest-Savanna Boundary

    OpenAIRE

    Karine S. Carvalho; Ane Alencar; Jennifer Balch; Paulo Moutinho

    2012-01-01

    Leaf-cutter ants (Atta spp.) remove leaf litter and woody debris—potential fuels—in and around their nests and foraging trails. We conducted single and three annual experimental fires to determine the effects of this leaf-cutter ant activity on the behavior of low-intensity, slow-moving fires. In a transitional forest, where the southern Amazon forest meets the Brazilian savanna, we tested whether leaf-cutter ant nests and trails (i) inhibit fire spread due to a lack of fuels, and (ii), there...

  5. Radiometric 81Kr dating identifies 120,000 year old ice at Taylor Glacier, Antarctica

    OpenAIRE

    Buizert, Christo; Baggenstos, Daniel; Jiang, Wei; Purtschert, Roland; Petrenko, Vasilii V.; Lu, Zheng-Tian; Müller, Peter; Kuhl, Tanner; Lee, James; Severinghaus, Jeffrey P.; Brook, Edward J.

    2014-01-01

    We present the first successful 81Kr-Kr radiometric dating of ancient polar ice. Krypton was extracted from the air bubbles in four ~350 kg polar ice samples from Taylor Glacier in the McMurdo Dry Valleys, Antarctica, and dated using Atom Trap Trace Analysis (ATTA). The 81Kr radiometric ages agree with independent age estimates obtained from stratigraphic dating techniques with a mean absolute age offset of 6 +/- 2.5 ka. Our experimental methods and sampling strategy are validated by 1) 85Kr ...

  6. The ejaculatory biology of leafcutter ants

    DEFF Research Database (Denmark)

    den Boer, Susanne; Stürup, Marlene; Boomsma, Jacobus Jan;

    2015-01-01

    The eusocial ants are unique in that females (queens) acquire and store sperm on a single mating flight early in adult life. This event largely determines the size (possibly millions of workers), longevity (possibly decades) and genetic variation of the colonies that queens found, but our...... understanding of the fundamental biology of ejaculate production, transfer and physiological function remains extremely limited. We studied the ejaculation process in the leafcutter ant Atta colombica and found that it starts with the appearance of a clear pre-ejaculatory fluid (PEF) at the tip of the...

  7. Al-Yawahir Al-Saniyya Fi Sarh-Al-Yarrumiyya, de Al-Ta c Alibi (s.VII-XIV)

    OpenAIRE

    Bellachehab, Ahmed

    1994-01-01

    Edición critica, realizada sobre varios manuscritos, de una interesante fuente gramatical magrebi, del siglo VIII de la hégira XIV de nuestra era. Estudio sobre el autor, at-ta alibi, típico gramático tardío del norte de África, y estudio sobre su producción escrita, en general y en concreto sobre este al-yawahir al-saniyya que es un interesante comentario de la celebre yarrumiyya, comentario hasta hoy inédito que representa un hito en la tradición de estudios gramaticales del occidente islám...

  8. NCBI nr-aa BLAST: CBRC-SARA-01-1167 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-SARA-01-1167 ref|XP_001105680.1| PREDICTED: similar to adiponectin receptor 1 ...isoform 3 [Macaca mulatta] ref|XP_001105751.1| PREDICTED: similar to adiponectin receptor 1 isoform 4 [Macac...a mulatta] ref|XP_001105805.1| PREDICTED: similar to adiponectin receptor 1 isoform 5 [Macaca mulatta] ref|X...P_001105878.1| PREDICTED: similar to adiponectin receptor 1 isoform 6 [Macaca mul...atta] ref|XP_001105957.1| PREDICTED: similar to adiponectin receptor 1 isoform 7 [Macaca mulatta] XP_001105680.1 1e-138 67% ...

  9. NCBI nr-aa BLAST: CBRC-OGAR-01-1050 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OGAR-01-1050 ref|XP_001105680.1| PREDICTED: similar to adiponectin receptor 1 ...isoform 3 [Macaca mulatta] ref|XP_001105751.1| PREDICTED: similar to adiponectin receptor 1 isoform 4 [Macac...a mulatta] ref|XP_001105805.1| PREDICTED: similar to adiponectin receptor 1 isoform 5 [Macaca mulatta] ref|X...P_001105878.1| PREDICTED: similar to adiponectin receptor 1 isoform 6 [Macaca mul...atta] ref|XP_001105957.1| PREDICTED: similar to adiponectin receptor 1 isoform 7 [Macaca mulatta] XP_001105680.1 0.0 92% ...

  10. NCBI nr-aa BLAST: CBRC-MLUC-01-1082 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-MLUC-01-1082 ref|XP_001105680.1| PREDICTED: similar to adiponectin receptor 1 ...isoform 3 [Macaca mulatta] ref|XP_001105751.1| PREDICTED: similar to adiponectin receptor 1 isoform 4 [Macac...a mulatta] ref|XP_001105805.1| PREDICTED: similar to adiponectin receptor 1 isoform 5 [Macaca mulatta] ref|X...P_001105878.1| PREDICTED: similar to adiponectin receptor 1 isoform 6 [Macaca mul...atta] ref|XP_001105957.1| PREDICTED: similar to adiponectin receptor 1 isoform 7 [Macaca mulatta] dbj|BAG16753.1| adiponectin receptor1 [Macaca fuscata] XP_001105680.1 0.0 87% ...

  11. Comportamento e dieta alimentar de uma espécie de Latrodectus do grupo Mactans (Araneae, Theridiidae em cativeiro Behavior and diet supply of Latrodectus group Mactans (Araneae, Theridiidae in captivity

    Directory of Open Access Journals (Sweden)

    Maria de Fátima da Rocha Dias

    1999-01-01

    Full Text Available Latrodectus gr. mactans is responsible for 28% of ali accidents provoked by spiders in state of Bahia, Brazil (1980-1990, which makes necessary the study of its manejament. The spiders were captured in Ondina, Salvador, and in Baxio, Esplanada (Bahia, Brazil; they were mantained in captivity, with food supply weekly (Atta sp., larva of Tenebrio sp. and Drosophila melanogaster with three hours/ offers observation time, during march/95 to april/96. In captivity, the spiders accepted two kinds of food: Atta sp., which seems to be the major item of its diet in natural conditions, and larva of Tenebrio sp., which is not available in natural conditions. Drosophila melanogaster was systematically rejected. The feeding behavior iscomposed by four distinct steps: (1 imrnobilization, (2 inoculation, (3 second immobilization and (4 ingestion. Two kinds of social alimentary behavior are descri-bed. The results indicated that larvae of Tenebrio sp. can be an alternative supply for successfull maintenance of this specie in captivity.

  12. Field evaluation of potential of alarm pheromone compounds to enhance baits for control of grass-cutting ants (Hymenoptera: Formicidae).

    Science.gov (United States)

    Hughes, William O H; Howse, Philip E; Vilela, Evaldo F; Knapp, Jenny J; Goulson, Dave

    2002-06-01

    Leaf-cutting ants are important economic pests of the Neotropics, and the most common method of control involves the use of insecticidal baits. Baits that are currently available exhibit low attractiveness to grass-cutting species, thus there is a need to develop improved baits. The potential for using alarm pheromone compounds to enhance the attractiveness and subsequent harvest of baits was examined for two economically important species of grass-cutting ant, Atta bisphaerica (Forel) and Atta capiguara (Goncalves). Compounds of the alarm pheromone were applied to rubber septa that were then sealed inside plastic sachets together with citrus pulp-based bait. The best candidate compound for bait enhancement was 4-methyl-3-heptanone. This compound significantly increased the attractiveness of bait sachets to both species. It also appeared to improve the discovery of nearby unenhanced sachets. However, 4-methyl-3-heptanone resulted in only a slight and non-significant improvement in bait harvest. Enhanced and unenhanced bait sachets were applied at a number of positions to obtain an improvement in harvest, but without success. The possible reasons for the lack of an enhancement of harvest and the potential for using alarm pheromone compounds as leaf-cutting ant bait enhancers are discussed. PMID:12075997

  13. Low host-pathogen specificity in the leaf-cutting ant-microbe symbiosis.

    Science.gov (United States)

    Taerum, Stephen J; Cafaro, Matías J; Little, Ainslie E F; Schultz, Ted R; Currie, Cameron R

    2007-08-22

    Host-parasite associations are shaped by coevolutionary dynamics. One example is the complex fungus-growing ant-microbe symbiosis, which includes ancient host-parasite coevolution. Fungus-growing ants and the fungi they cultivate for food have an antagonistic symbiosis with Escovopsis, a specialized microfungus that infects the ants' fungus gardens. The evolutionary histories of the ant, cultivar and Escovopsis are highly congruent at the deepest phylogenetic levels, with specific parasite lineages exclusively associating with corresponding groups of ants and cultivar. Here, we examine host-parasite specificity at finer phylogenetic levels, within the most derived clade of fungus-growing ants, the leaf-cutters (Atta spp. and Acromyrmex spp.). Our molecular phylogeny of Escovopsis isolates from the leaf-cutter ant-microbe symbiosis confirms specificity at the broad phylogenetic level, but reveals frequent host-switching events between species and genera of leaf-cutter ants. Escovopsis strains isolated from Acromyrmex and Atta gardens occur together in the same clades, and very closely related strains can even infect the gardens of both ant genera. Experimental evidence supports low host-parasite specificity, with phylogenetically diverse strains of Escovopsis being capable of overgrowing all leaf-cutter cultivars examined. Thus, our findings indicate that this host-pathogen association is shaped by the farming ants having to protect their cultivated fungus from phylogenetically diverse Escovopsis garden pathogens. PMID:17550881

  14. Islam sebagai Agama dan Peradaban

    Directory of Open Access Journals (Sweden)

    Qosim Nursheha Dzulhadi

    2015-10-01

    Full Text Available Islam and civilization can not be separated. Since its presence, Islam has brought the concept and mission of civilization that is inherent in it. Islamic civilization sourced from dîn (religion which came from the revelation of Allah. That is why the civilization well known as tamaddun or madaniyyah, because it comes from that dîn . Then the high expression tamaddun Islam in the history of human civilization got its place in Yathrib wich later turned into Medina. So, Medina is the place where tamaddun was proclaimed to the whole world as described by Syed Muhammad Naquib al-Attas. And madaniyyah, according to Muhammad ‘Abduh is more appropriately used to refer to Islamic civilization, because the spiritual aroma-religion (al-dîn is more pronounced and prominent. Departing from this, this article will break down the details of the meaning and concept of civilization, in which the comparison will be made between the concepts of Western civilization with Islamic civilization.This is necessary in order to provide a clearer distinction of the two concepts of civilization.This article will also review the nature of Islam as dîn and tamaddun-madaniyyah with based on the views of the two great Muslim thinkers, Muhammad ‘Abduh and Syed Muhammad Naquib al-Attas. In addition will include also a critique of modern Western civilization, which is currently hegemonic civilization.

  15. Predatory Behavior of Canthon virens (Coleoptera: Scarabaeidae: A Predator of Leafcutter Ants

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Forti

    2012-01-01

    Full Text Available We present a detailed description of the predatory behavior of the beetle Canthon virens Mannerheim, 1829, on the leafcutter ant Atta sp. We observed 51 acts of predation, which were also recorded on film and subjected to behavioral analysis. Canthon virens exhibited 28 behaviors while predating upon Atta sp. queens. Adult beetles search for queens while flying in a zigzag pattern, 15 to 20 cm above the ground. After catching a queen, the predator stands on its back and starts cutting the queen cervix. Once the prey is decapitated, the predator rolls it until an insurmountable obstacle is reached. The distance from the site of predation to the obstacle can vary widely and is unpredictable. The beetle rolling the queen also buries it in a very peculiar way: first, it digs a small hole and pulls the queen inside, while another beetle is attached to the prey. The burial process takes many hours (up to 12 and may depend on the hardness of the soil and the presence of obstacles. In general, one or two beetles are found in a chamber with the queen after it is buried. They make the brood balls, which serve as food for the offspring. This study contributes to the knowledge of the predatory behavior of Canthon virens, a predator poorly studied in Brazil and widespread in the country.

  16. Automated Sampling and Extraction of Krypton from Small Air Samples for Kr-85 Measurement Using Atom Trap Trace Analysis

    International Nuclear Information System (INIS)

    Atom-Trap-Trace-Analysis (ATTA) provides the capability of measuring the Krypton-85 concentration in microlitre amounts of krypton extracted from air samples of about 1 litre. This sample size is sufficiently small to allow for a range of applications, including on-site spot sampling and continuous sampling over periods of several hours. All samples can be easily handled and transported to an off-site laboratory for ATTA measurement, or stored and analyzed on demand. Bayesian sampling methodologies can be applied by blending samples for bulk measurement and performing in-depth analysis as required. Prerequisite for measurement is the extraction of a pure krypton fraction from the sample. This paper introduces an extraction unit able to isolate the krypton in small ambient air samples with high speed, high efficiency and in a fully automated manner using a combination of cryogenic distillation and gas chromatography. Air samples are collected using an automated smart sampler developed in-house to achieve a constant sampling rate over adjustable time periods ranging from 5 minutes to 3 hours per sample. The smart sampler can be deployed in the field and operate on battery for one week to take up to 60 air samples. This high flexibility of sampling and the fast, robust sample preparation are a valuable tool for research and the application of Kr-85 measurements to novel Safeguards procedures. (author)

  17. A chimeric protein of aluminum-activated malate transporter generated from wheat and Arabidopsis shows enhanced response to trivalent cations.

    Science.gov (United States)

    Sasaki, Takayuki; Tsuchiya, Yoshiyuki; Ariyoshi, Michiyo; Ryan, Peter R; Yamamoto, Yoko

    2016-07-01

    TaALMT1 from wheat (Triticum aestivum) and AtALMT1 from Arabidopsis thaliana encode aluminum (Al)-activated malate transporters, which confer acid-soil tolerance by releasing malate from roots. Chimeric proteins from TaALMT1 and AtALMT1 (Ta::At, At::Ta) were previously analyzed in Xenopus laevis oocytes. Those studies showed that Al could activate malate efflux from the Ta::At chimera but not from At::Ta. Here, functions of TaALMT1, AtALMT1 and the chimeric protein Ta::At were compared in cultured tobacco BY-2 cells. We focused on the sensitivity and specificity of their activation by trivalent cations. The activation of malate efflux by Al was at least two-fold greater in the chimera than the native proteins. All proteins were also activated by lanthanides (erbium, ytterbium, gadolinium, and lanthanum), but the chimera again released more malate than TaALMT1 or AtALMT1. In Xenopus oocytes, Al, ytterbium, and erbium activated inward currents from the native TaALMT1 and the chimeric protein, but gadolinium only activated currents from the chimera. Lanthanum inhibited currents from both proteins. These results demonstrated that function of the chimera protein was altered compared to the native proteins and was more responsive to a range of trivalent cations when expressed in plant cells. PMID:27039280

  18. Prevalence of the genus Cladosporium on the integument of leaf-cutting ants characterized by 454 pyrosequencing.

    Science.gov (United States)

    Duarte, A P M; Ferro, M; Rodrigues, A; Bacci, M; Nagamoto, N S; Forti, L C; Pagnocca, F C

    2016-09-01

    The relationship of attine ants with their mutualistic fungus and other microorganisms has been studied during the last two centuries. However, previous studies about the diversity of fungi in the ants' microenvironment are based mostly on culture-dependent approaches, lacking a broad characterization of the fungal ant-associated community. Here, we analysed the fungal diversity found on the integument of Atta capiguara and Atta laevigata alate ants using 454 pyrosequencing. We obtained 35,453 ITS reads grouped into 99 molecular operational taxonomic units (MOTUs). Data analysis revealed that A. capiguara drones had the highest diversity of MOTUs. Besides the occurrence of several uncultured fungi, the mycobiota analysis revealed that the most abundant taxa were the Cladosporium-complex, Cryptococcus laurentii and Epicoccum sp. Taxa in the genus Cladosporium were predominant in all samples, comprising 67.9 % of all reads. The remarkable presence of the genus Cladosporium on the integument of leaf-cutting ants alates from distinct ant species suggests that this fungus is favored in this microenvironment. PMID:27307255

  19. Laboratory for Radiokrypton Dating

    Science.gov (United States)

    Lu, Z.; Bailey, K.; Jiang, W.; Müller, P.; O'Connor, T. P.; Zappala, J. C.

    2013-12-01

    Due to its simple production and transport processes in the terrestrial environment, the long-lived noble-gas isotope 81Kr (half-life = 230 kyr) is the ideal tracer for studying old water and ice in the age range of 10^5-10^6 years, a range beyond the reach of 14C. 81Kr dating, a concept pursued in the past four decades by numerous laboratories employing a variety of techniques, is now available for the first time to the earth science community at large. This is made possible by the development of ATTA-3 (Jiang et al., GCA 91, 1-6; 2012), an efficient and selective atom counter based on the Atom Trap Trace Analysis method (Chen et al., Science 286, 1139-1141; 1999). The instrument is capable of measuring both 81Kr/Kr and 85Kr/Kr ratios of environmental samples in the range of 10^-14-10^-10. For 81Kr-dating in the age range of 150 - 1,500 kyr, the required sample size is 5 - 10 micro-L STP of krypton gas, which can be extracted from approximately 100 - 200 kg of water or 40 - 80 kg of ice. For 85Kr/Kr analysis, the required sample size is generally smaller by an order of magnitude because of the isotope's higher initial abundance in the atmosphere. The Laboratory for Radiokrypton Dating is currently equipped to analyze up to 120 samples per year. With future equipment upgrades, this limit can be increased as demand grows. In the period since November 2011, the Laboratory has measured both 81Kr/Kr and 85Kr/Kr ratios in over 50 samples that had been extracted by collaborators from six different continents. The samples were from groundwater wells in the Great Artesian Basin (Australia), Guarani Aquifer (Brazil), and Locust Grove (Maryland); from brine wells of the Waste Isolation Pilot Plant (New Mexico); from geothermal steam vents in Yellowstone National Park; from near-surface ice at Taylor Glacier, Antarctica; and from deep mines in South Africa. Sample collection and purification was performed by groups including the University of Illinois at Chicago, University

  20. Preparation of a novel colorimetric luminescence sensor strip for the detection of indole-3-acetic acid.

    Science.gov (United States)

    Liu, Yan; Dong, Haitao; Zhang, Wenzhu; Ye, Zhiqiang; Wang, Guilan; Yuan, Jingli

    2010-06-15

    A novel colorimetric luminescence sensor strip for the detection of indole-3-acetic acid (IAA) has been fabricated by using green emissive quantum dots of cadmium telluride (CdTe QDs) as a background layer and a red emissive europium chelate, [4'-(9-anthryl)-2,2':6',2''-terpyridine-6,6''-diyl]bis(methylenenitrilo) tetrakis(acetate)-Eu(3+) (ATTA-Eu(3+)), as a specific sensing layer coated on the surface of glass slide, respectively. The luminescence response of the sensor strip is given by the dramatic changes in emission colors from green to red at different IAA concentrations. This approach provides a simple, rapid, sensitive and accurate method for the detection of IAA without using any special scientific instruments. PMID:20353890

  1. Structure of Stacked Dimers of N-Methylated Watson–Crick Adenine–Thymine Base Pairs

    Directory of Open Access Journals (Sweden)

    Sándor Suhai

    2003-09-01

    Full Text Available Abstract: The structure of two isomeric stacked dimers of Watson-Crick 9-methyladenine-1-methylthymine pairs was fully optimized using an approximate density functional theory (DFT method augmented with an empirical dispersion interaction. The results of the calculations reveal that head-to-tail (AT-TA and head-to-head (AT-AT dimers possess a significantly different geometry. The structure of both complexes is stabilized by vertical CH…O and C-H…N hydrogen bonds with the participation of the hydrogen atoms of the methyl groups. The energy of hydrogen bonding and stacking interactions was additionally calculated using the MP2/6-31G*(0.25 method. Differences in the mutual arrangement of the base pairs in two isomeric dimers lead to significant changes of intra and interstrand stacking interaction energies.

  2. Novel fungal disease in complex leaf-cutting ant societies

    DEFF Research Database (Denmark)

    Hughes, David Peter; Evans, Harry C.; Hywel-Jones, Nigel;

    2009-01-01

    1. The leaf-cutting ants practise an advanced system of mycophagy where they grow a fungus as a food source. As a consequence of parasite threats to their crops, they have evolved a system of morphological, behavioural, and chemical defences, particularly against fungal pathogens (mycopathogens). 2....... Specific fungal diseases of the leaf-cutting ants themselves have not been described, possibly because broad spectrum anti-fungal defences against mycopathogens have reduced their susceptibility to entomopathogens. 3. Using morphological and molecular tools, the present study documents three rare infection...... events of Acromyrmex and Atta leaf-cutting ants by Ophiocordyceps fungi, agenus of entomopathogens that is normally highly specific in its host choice. 4. As leaf-cutting ants have been intensively studied, the absence of prior records of Ophiocordyceps suggests that these infections may be a novel event...

  3. Sperm storage induces an immunity cost in ants

    DEFF Research Database (Denmark)

    Baer, Boris; Armitage, Sophie A O; Boomsma, Jacobus J

    2006-01-01

    Ant queens are among the most long-lived insects known. They mate early in adult life and maintain millions of viable sperm in their sperm storage organ until they die many years later. Because they never re-mate, the reproductive success of queens is ultimately sperm-limited, but it is not known...... what selective forces determine the upper limit to sperm storage. Here we show that sperm storage carries a significant cost of reduced immunity during colony founding. Newly mated queens of the leaf-cutting ant Atta colombica upregulate their immune response shortly after completing their nest burrow......, probably as an adaptive response to a greater exposure to pathogens in the absence of grooming workers. However, the immune response nine days after colony founding is negatively correlated with the amount of sperm in the sperm storage organ, indicating that short-term survival is traded off against long...

  4. Dicty_cDB: Contig-U15907-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available atta Major Histocompatibility Complex B... 56 0.005 1 ( AC148668 ) Macaca mulatta Major Histocompatibility...1297( CP000879 |pid:none) Petrotoga mobilis SJ95, complet... 149 6e-53 CP000382_9...1e-54 CP000117_3001( CP000117 |pid:none) Anabaena variabilis ATCC 29413,... 167 1e-54 BA000039_961( BA000039 |pid:none) Thermo...DQ157431_1( DQ157431 |pid:none) Canis lupus familiaris ATP-binding... 150 1e-60 BC042531_1( BC042531 |pid:none) Homo sapiens ATP-bi...e-55 CP000557_469( CP000557 |pid:none) Geobacillus thermodenitrificans ... 162 1e-55 AL022197_18( AL022197 |pid:none) Arabi

  5. Trace analyses at the single particle level with Atom Trap Trace Analysis for 39Ar

    International Nuclear Information System (INIS)

    Atom optics has found many applications in different fields of physics. In the context of environmental physics the method of Atom Trap Trace Analysis (ATTA) has opened a new level of dating of water in the regime of very old water (millions of years) with 81Kr and recent water of the last 1000 years with 39Ar. The latter is the topic of this seminar revealing the challenges and experimental solutions to work with 39Ar concentrations in Ar as small as 1:1016. After the detailed discussion of the experimental techniques I will present the first results on dating of water with this method [1] and discuss the potential for samples as small as 1 liter. Being able to date such small samples we will open up a route for detecting the age distribution of the oceans. (author)

  6. Identifying the transition between single and multiple mating of queens in fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Murakami, Takahiro; Schultz, Ted R;

    2002-01-01

    Obligate mating of females (queens) with multiple males has evolved only rarely in social Hymenoptera (ants, social bees, social wasps) and for reasons that are fundamentally different from those underlying multiple mating in other animals. The monophyletic tribe of ('attine') fungus-growing ants...... is known to include evolutionarily derived genera with obligate multiple mating (the Acromyrmex and Atta leafcutter ants) as well as phylogenetically basal genera with exclusively single mating (e.g. Apterostigma, Cyphomyrmex, Myrmicocrypta). All attine genera share the unique characteristic of...... obligate dependence on symbiotic fungus gardens for food, but the sophistication of this symbiosis differs considerably across genera. The lower attine genera generally have small, short-lived colonies and relatively non-specialized fungal symbionts (capable of living independently of their ant hosts...

  7. Faunistic analysis of Formicidae (Hymenoptera: Apocrita in degraded ecosystems of Chapecó town, Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    Flávio Roberto Mello Garcia

    2005-11-01

    Full Text Available Seeking to investigate the ant fauna in degraded environments and to comprehend how this group behaves in such ecosystems, faunistic analysis was initially conducted with the ants collected in an area in Chapecó town that had been subjected to flooding in function of the construction of the mouth of a dam on the Chapecó River (a branch of the larger Uruguay River. The collections were carried out between October 2001 and September 2002. We used pit-fall traps, sweeping nets, entomologic umbrellas and leaf litter collections for fragments covered by bushes and grass. The fauna was characterized through the constancy and dominancy indexes. A number of 34.642 specimens of ants, belonging to 32 species, 19 genera and six subfamilies, were collected. The species Labidus sp., Atta sp. and Ectatomma edentatum stood out as being either accessory or both constant and dominant.

  8. Tracing Noble Gas Radionuclides in the Environment

    CERN Document Server

    Collon, P; Lu, Z T

    2004-01-01

    Trace analysis of radionuclides is an essential and versatile tool in modern science and technology. Due to their ideal geophysical and geochemical properties, long-lived noble gas radionuclides, in particular, 39Ar (t1/2 = 269 yr), 81Kr (t1/2 = 2.3x10^5 yr) and 85Kr (t1/2 = 10.8 yr), have long been recognized to have a wide range of important applications in Earth sciences. In recent years, significant progress has been made in the development of practical analytical methods, and has led to applications of these isotopes in the hydrosphere (tracing the flow of groundwater and ocean water). In this article, we introduce the applications of these isotopes and review three leading analytical methods: Low-Level Counting (LLC), Accelerator Mass Spectrometry (AMS) and Atom Trap Trace Analysis (ATTA).

  9. Insetos em presépios e as "formigas vestidas" de Jules Martin (1832-1906: uma curiosa manufatura paulistana do final do século XIX

    Directory of Open Access Journals (Sweden)

    Dante Martins Teixeira

    2008-01-01

    Full Text Available Present in Brazil since the beginning of Portuguese colonization, crèche nativity scenes were soon adapted to local reality, a propitious circumstance for the appearance of heterodox conceptions and the use of exotic elements of the fauna and flora peculiar to each region. As records about insects are very uncommon, it is noteworthy that females of leaf-cutting ants, Atta sp. (Hymenoptera, Formicidae, were used to compose crèche nativity scenes in São Paulo State. Having subsisted at least up to the decade of 1960, the "ant crèches" of cities such as Embu das Artes could be related to the then famous "dressed ants" created by Jules Martin, a curious manufacture of the city of São Paulo in the last quarter of the 19th century.

  10. Dicty_cDB: Contig-U14831-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 2_509( CP001102 |pid:none) Candidatus Amoebophilus asiaticu... 53 2e-05 CP000115_2724( CP000115 |pid:none) Nitrobacter winogra...M_Contig/Contig-U14831-1Q.Seq.d Length = 1069 Score = 1741 bits (878), Expect = 0.0 Identities = 878/878 (100%) Stra... 1055 Score = 32.2 bits (16), Expect = 1.2 Identities = 16/16 (100%) Strand = Plus / Minus Query: 2 ttattaat...ntig-U11587-1Q.Seq.d Length = 2537 Score = 42.1 bits (21), Expect = 0.001 Identities = 21/21 (100%) Stra...h = 254 Score = 42.1 bits (21), Expect = 0.001 Identities = 21/21 (100%) Strand = Plus / Minus Query: 1 atta

  11. Raise your defence: a baseline for security

    CERN Multimedia

    Computer Security Team

    2011-01-01

    It is an unfair imbalance: the (computer) security of a system/service is only as strong as the weakest link in the chain of protection. This provides attackers with an incredible advantage: they can choose when to attack, where and with which means. The defence side is permanently under pressure: they must defend at all times all assets against all eventualities. For computer security, this means that every computer system, every account, every web site and every service must be properly protected --- always.   In particular, at CERN, those services visible to the Internet are permanently probed. Web sites and servers are permanently scanned by adversaries for vulnerabilities; attackers repeatedly try to guess user passwords on our remote access gateways like LXPLUS or CERNTS; computing services, e.g. for Grid computing, are analysed again and again by malicious attackers for weaknesses which can be exploited. Thanks to the vigilance of the corresponding system and service experts, these atta...

  12. On the topologic structure of economic complex networks: Empirical evidence from large scale payment network of Estonia

    CERN Document Server

    de la Torre, Stephanie Rendón; Kitt, Robert; Engelbrecht, Jüri

    2016-01-01

    This paper presents the first topological analysis of the economic structure of an entire country based on payments data obtained from Swedbank. This data set is exclusive in its kind because around 80% of Estonia's bank transactions are done through Swedbank, hence, the economic structure of the country can be reconstructed. Scale-free networks are commonly observed in a wide array of different contexts such as nature and society. In this paper, the nodes are comprised by customers of the bank (legal entities) and the links are established by payments between these nodes. We study the scaling-free and structural properties of this network. We also describe its topology, components and behaviors. We show that this network shares typical structural characteristics known in other complex networks: degree distributions follow a power law, low clustering coefficient and low average shortest path length. We identify the key nodes of the network and perform simulations of resiliency against random and targeted atta...

  13. Uninformed sacrifice: Evidence against long-range alarm transmission in foraging ants exposed to localized abduction

    Science.gov (United States)

    Tejera, F.; Reyes, A.; Altshuler, E.

    2016-07-01

    It is well established that danger information can be transmitted by ants through relatively small distances, provoking either a state of alarm when they move away from potentially dangerous stimulus, or charge toward it aggressively. There is almost no knowledge if danger information can be transmitted along large distances. In this paper, we abduct leaf cutting ants of the species Atta insularis while they forage in their natural environment at a certain point of the foraging line, so ants make a "U" turn to escape from the danger zone and go back to the nest. Our results strongly suggest that those ants do not transmit "danger information" to other nestmates marching towards the abduction area. The individualistic behavior of the ants returning from the danger zone results in a depression of the foraging activity due to the systematic sacrifice of non-informed individuals.

  14. Simple cellular automata to mimic foraging ants submitted to abduction

    CERN Document Server

    Tejera, F

    2015-01-01

    Many species of ants forage by building up two files: an outbound one moving from the nest to the foraging area, and a nestbound one, returning from it to the nest. Those files are eventually submitted to different threats. If the danger is concentrated at one point of the file, one might expect that ants returning to the nest will pass danger information to their nestmates moving in the opposite direction towards the danger area. In this paper, we construct simple cellular automata models for foraging ants submitted to localized abduction, were danger information is transmitted using different protocols, including the possibility of no transmission. The parameters we have used in the simulations have been estimated from actual experiments under natural conditions. So, it would be easy to test our information-transmission hypothese in real experiments. Preliminary experimental results published elsewhere suggest that the behavior of foraging ants of the species Atta insularis is best described using the hypot...

  15. The conversion of SO{sub 2} to SO{sub 3} in gas turbine engines

    Energy Technology Data Exchange (ETDEWEB)

    Miake-Lye, R.C.; Anderson, M.R.; Brown, R.C.; Kolb, C.E. [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics; Sorokin, A.A.; Buriko, Y.I. [Scientific Research Center `Ecolen`, Moscow (Russian Federation)

    1997-12-31

    The oxidation of fuel sulfur to S(6) (SO{sub 3}+H{sub 2}SO{sub 4}) in a supersonic (Concorde) and a subsonic (ATTAS) aircraft engine is estimated numerically. The results indicate between 2% and 10% of the fuel sulfur is emitted as S(6). It is also shown that conversion in the turbine is limited by the level of atomic oxygen at the combustor exit, resulting in a higher oxidation efficiency as the sulfur mass loading is decreased. SO{sub 2} and SO{sub 3} are the primary sulfur oxidation products, with less than 1% of fuel sulfur converted to H{sub 2}SO{sub 4}. For the Concorde, H{sub 2}SO{sub 4} was primarily formed during the supersonic expansion through the divergent nozzle. (author) 20 refs.

  16. Analysis of SSR in Citrus Sequences from EMBL Database

    Institute of Scientific and Technical Information of China (English)

    MENG Hai-jun; CAO Qing-qin; HU Zhi-yong; LIU Gao-ping; CHENG Yun-jiang; DENG Xiu-xin

    2005-01-01

    Abundance of simple sequence repeat (SSR) in Citrus sequences from EMBL database was investigated by using computer program MISA (MIcroSAtellite), which aimed to provide useful information for the development of SSR markers.Among 32 896 sequences of Citrus, 4987 SSRs were found in 4167 sequences and the average distance between SSRs was approximately 3.5 kb. Mononucleotide repeats (50.6%) were the most abundant repeats. And di-, tri-, tetra-, penta- and hexa-nucleotide repeats were 22.8, 25.2, 1, 0.08, and 0.36%, respectively. The most abundant motif was A/T followed in descending order by AG/CT, AC/GT, AT/TA. AAT/ATT, AAG/CTT, AGC/CGT, ACG/CTG and C/G. They comprised about90% of all microsatellites. Ten primer pairs were designed, and three of them produced clear visible bands among Citrus and its related genera.

  17. Recent developments on field gas extraction and sample preparation methods for radiokrypton dating of groundwater

    Science.gov (United States)

    Yokochi, Reika

    2016-09-01

    Current and foreseen population growths will lead to an increased demand in freshwater, large quantities of which is stored as groundwater. The ventilation age is crucial to the assessment of groundwater resources, complementing the hydrological model approach based on hydrogeological parameters. Ultra-trace radioactive isotopes of Kr (81 Kr and 85 Kr) possess the ideal physical and chemical properties for groundwater dating. The recent advent of atom trap trace analyses (ATTA) has enabled determination of ultra-trace noble gas radioisotope abundances using 5-10 μ L of pure Kr. Anticipated developments will enable ATTA to analyze radiokrypton isotope abundances at high sample throughput, which necessitates simple and efficient sample preparation techniques that are adaptable to various sample chemistries. Recent developments of field gas extraction devices and simple and rapid Kr separation method at the University of Chicago are presented herein. Two field gas extraction devices optimized for different sampling conditions were recently designed and constructed, aiming at operational simplicity and portability. A newly developed Kr purification system enriches Kr by flowing a sample gas through a moderately cooled (138 K) activated charcoal column, followed by a gentle fractionating desorption. This simple process uses a single adsorbent and separates 99% of the bulk atmospheric gases from Kr without significant loss. The subsequent two stages of gas chromatographic separation and a hot Ti sponge getter further purify the Kr-enriched gas. Abundant CH4 necessitates multiple passages through one of the gas chromatographic separation columns. The presented Kr separation system has a demonstrated capability of extracting Kr with > 90% yield and 99% purity within 75 min from 1.2 to 26.8 L STP of atmospheric air with various concentrations of CH4. The apparatuses have successfully been deployed for sampling in the field and purification of groundwater samples.

  18. Exposure of Workers of Ectatomma brunneum Smith (Hymenoptera: Formicidae: Ectatomminae to ant Baits Containing Different Active Ingredients under Laboratory Conditions

    Directory of Open Access Journals (Sweden)

    Viviane Tofolo

    2015-03-01

    Resumo. Este trabalho avaliou a mortalidade a curto prazo de operárias de Ectatomma brunneum Smith expostas a iscas formicidas em laboratório, a fim de verificar se a capacidade de atração desta espécie não-alvo a formicidas destinadas ao controle de formigas cortadeiras (alvo pode ser prejudicial para a população estudada. As operárias foram expostas em laboratório por 48 horas a iscas formicidas utilizadas em pastagens para controlar as formigas cortadeiras Atta capiguara Gonçalves (Formicidae: Attini e Atta bisphaerica Forel (Formicidae: Attini, as principais espécies que causam danos às pastagens. Foram utilizados os seguintes ingredientes ativos: sulfluramida 0,3%, fipronil 0,003% e clorpirifos 0,45%. O experimento foi composto por grupos de 30 operárias expostas a 10g de formicidas, usando três repetições. Foi realizado o acompanhamento diário da mortalidade durante 20 dias, registrando-se o número de operárias mortas e intoxicadas. O grupo controle recebeu apenas 10g de polpa cítrica umedecida. A partir de resultados obtidos, as curvas de sobrevivência em função do tempo de observação foram plotadas usando o método de Kaplan-Meier, e comparadas com aplicação do Logrank test (teste não-paramétrico em nível de significância de 5%. Os resultados revelaram que os três ingredientes ativos testados foram tóxicos e a população reduzida em 35.56% no tratamento com clorpirifós, 31,11% com sulfluramida e 30% com fipronil.

  19. Representation of thermal information in the antennal lobe of leaf-cutting ants

    Directory of Open Access Journals (Sweden)

    Markus eRuchty

    2010-11-01

    Full Text Available Insects are equipped with various types of antennal sensilla, which house thermosensitive neurons adapted to receive different parameters of the thermal environment for a variety of temperature-guided behaviors. In the leaf-cutting ant Atta vollenweideri, the physiology and the morphology of the thermosensitive sensillum coeloconicum (Sc has been thoroughly investigated. However, the central projections of its receptor neurons are unknown. Here we selectively stained the three neurons found in single Sc and tracked their axons into the brain of Atta vollenweideri workers. Each of the three axons terminates in a single glomerulus of the antennal lobe (Sc-glomeruli. Two of the innervated glomeruli are adjacent to each other and are located laterally, while the third one is clearly separated and located medially in the antennal lobe. Using two-photon Ca2+ imaging of antennal lobe projection neurons, we studied where in the antennal lobe thermal information is represented. In the 11 investigated antennal lobes, we found up to 10 different glomeruli in a single specimen responding to temperature stimulation. Both, warm- and cold-sensitive glomeruli could be identified. The thermosensitive glomeruli were mainly located in the medial part of the antennal lobe. Based on the general representation of thermal information in the antennal lobe and functional data on the Sc-glomeruli we conclude that temperature stimuli received by Sc are processed in the medial of the three target glomeruli. The present study reveals an important role of the antennal lobe in temperature processing and links a specific thermosensitive neuron to its central target glomerulus.

  20. Evolution Analysis of Simple Sequence Repeats in Plant Genome.

    Directory of Open Access Journals (Sweden)

    Zhen Qin

    Full Text Available Simple sequence repeats (SSRs are widespread units on genome sequences, and play many important roles in plants. In order to reveal the evolution of plant genomes, we investigated the evolutionary regularities of SSRs during the evolution of plant species and the plant kingdom by analysis of twelve sequenced plant genome sequences. First, in the twelve studied plant genomes, the main SSRs were those which contain repeats of 1-3 nucleotides combination. Second, in mononucleotide SSRs, the A/T percentage gradually increased along with the evolution of plants (except for P. patens. With the increase of SSRs repeat number the percentage of A/T in C. reinhardtii had no significant change, while the percentage of A/T in terrestrial plants species gradually declined. Third, in dinucleotide SSRs, the percentage of AT/TA increased along with the evolution of plant kingdom and the repeat number increased in terrestrial plants species. This trend was more obvious in dicotyledon than monocotyledon. The percentage of CG/GC showed the opposite pattern to the AT/TA. Forth, in trinucleotide SSRs, the percentages of combinations including two or three A/T were in a rising trend along with the evolution of plant kingdom; meanwhile with the increase of SSRs repeat number in plants species, different species chose different combinations as dominant SSRs. SSRs in C. reinhardtii, P. patens, Z. mays and A. thaliana showed their specific patterns related to evolutionary position or specific changes of genome sequences. The results showed that, SSRs not only had the general pattern in the evolution of plant kingdom, but also were associated with the evolution of the specific genome sequence. The study of the evolutionary regularities of SSRs provided new insights for the analysis of the plant genome evolution.

  1. Method for purification of Kr from environmental samples for analysis of radiokrypton isotopes

    Science.gov (United States)

    Yokochi, R.; Heraty, L. J.; Sturchio, N. C.

    2008-12-01

    Two extremely low-abundance radioactive isotopes of Kr ((81Kr and (85Kr) are produced by cosmic-ray induced spallation (81Kr /Kr = 10-12, t½ = 229,000 yr) and by a nuclear fission (85Kr /Kr = 10-11, t½ = 10.8 yr). Radiokrypton chronologies are potentially important in diverse studies of hydrology and paleoclimate and the inertness of Kr, being a noble gas, makes radiokrypton-based chronometers superior to other hydrological tracers for many such applications (e.g., 3H-He, 14C, 36Cl, CFCs, SF6). The analysis of 81Kr in naturally occurring gases of interest, e.g. dissolved gases in hydrological reservoirs, using Atom Trap Trace Analysis (ATTA) requires an extraction of ppm-level Kr from chemically air-like bulk gas. A newly developed Kr purification system is based on conventional cryogenic distillation and gas chromatography to which continuous monitoring of gas effluent composition using quadrupole mass spectrometer brings significant advantages. Simple cryogenic distillation is controlled based on the evolution of N2/Ar ratio that is relatively constant in naturally occurring, inorganic gas. Gas chromatographic separation of ppmv-level Kr from up to a few liter of bulk gas can be achieved by concentrating the Kr under the tails of major components. The system described here is capable of extracting Kr from 5-125 lSTP of bulk gas with >90% yield within several hours. Gas samples have been taken at several hydrological and geological settings: shallow groundwater at Locust Grove, MD, gas emanation from Cheaspeake Crater, VA, mid-continental saline groundwater (KS, MO), deep and shallow groundwater from northern Chile (Atacama desert), and the hydrothermal system at Yellowstone National Park, WY. Our new method was used successfully to purify microliter amounts of Kr from all of these samples, an important step en route to routine application of ATTA in hydrological studies. This work was supported by the Camille and Henry Dreyfus Postdoctoral Program in

  2. Variation in genomic landscape of clear cell renal cell carcinoma across Europe.

    Science.gov (United States)

    Scelo, Ghislaine; Riazalhosseini, Yasser; Greger, Liliana; Letourneau, Louis; Gonzàlez-Porta, Mar; Wozniak, Magdalena B; Bourgey, Mathieu; Harnden, Patricia; Egevad, Lars; Jackson, Sharon M; Karimzadeh, Mehran; Arseneault, Madeleine; Lepage, Pierre; How-Kit, Alexandre; Daunay, Antoine; Renault, Victor; Blanché, Hélène; Tubacher, Emmanuel; Sehmoun, Jeremy; Viksna, Juris; Celms, Edgars; Opmanis, Martins; Zarins, Andris; Vasudev, Naveen S; Seywright, Morag; Abedi-Ardekani, Behnoush; Carreira, Christine; Selby, Peter J; Cartledge, Jon J; Byrnes, Graham; Zavadil, Jiri; Su, Jing; Holcatova, Ivana; Brisuda, Antonin; Zaridze, David; Moukeria, Anush; Foretova, Lenka; Navratilova, Marie; Mates, Dana; Jinga, Viorel; Artemov, Artem; Nedoluzhko, Artem; Mazur, Alexander; Rastorguev, Sergey; Boulygina, Eugenia; Heath, Simon; Gut, Marta; Bihoreau, Marie-Therese; Lechner, Doris; Foglio, Mario; Gut, Ivo G; Skryabin, Konstantin; Prokhortchouk, Egor; Cambon-Thomsen, Anne; Rung, Johan; Bourque, Guillaume; Brennan, Paul; Tost, Jörg; Banks, Rosamonde E; Brazma, Alvis; Lathrop, G Mark

    2014-01-01

    The incidence of renal cell carcinoma (RCC) is increasing worldwide, and its prevalence is particularly high in some parts of Central Europe. Here we undertake whole-genome and transcriptome sequencing of clear cell RCC (ccRCC), the most common form of the disease, in patients from four different European countries with contrasting disease incidence to explore the underlying genomic architecture of RCC. Our findings support previous reports on frequent aberrations in the epigenetic machinery and PI3K/mTOR signalling, and uncover novel pathways and genes affected by recurrent mutations and abnormal transcriptome patterns including focal adhesion, components of extracellular matrix (ECM) and genes encoding FAT cadherins. Furthermore, a large majority of patients from Romania have an unexpected high frequency of A:T>T:A transversions, consistent with exposure to aristolochic acid (AA). These results show that the processes underlying ccRCC tumorigenesis may vary in different populations and suggest that AA may be an important ccRCC carcinogen in Romania, a finding with major public health implications. PMID:25351205

  3. Ultra-High Strength and Ductile Lamellar-Structured Powder Metallurgy Binary Ti-Ta Alloys

    Science.gov (United States)

    Liu, Yong; Xu, Shenghang; Wang, Xin; Li, Kaiyang; Liu, Bin; Wu, Hong; Tang, Huiping

    2016-03-01

    Ultra-high strength and ductile powder metallurgy (PM) binary Ti-20at.%Ta alloy has been fabricated via sintering from elemental Ti and Ta powders and subsequent hot swaging and annealing. The microstructural evolution and mechanical properties in each stage were evaluated. Results show that inhomogeneous microstructures with Ti-rich and Ta-rich areas formed in the as-sintered Ti-Ta alloys due to limited diffusion of Ta. In addition, Kirkendall porosity was observed as a result of the insufficient diffusion of Ta. Annealing at 1000°C for up to 24 h failed to eliminate the pores. Hot swaging eliminated the residual sintering porosity and created a lamellar microstructure, consisting of aligned Ta-enriched and Ti-enriched phases. The hot-swaged and annealed PM Ti-20Ta alloy achieved an ultimate tensile strength of 1600 MPa and tensile elongation of more than 25%, due to its unique lamellar microstructure including the high toughness of Ta-enriched phases, the formation of α phase in the β matrix and the refined lamellae.

  4. Isolation and molecular characterization of symbiotic fungus from Acromyrmex ambiguus and Acromyrmex heyeri ants of Rio Grande do Sul State, Brazil

    Directory of Open Access Journals (Sweden)

    Daniela Isabel Brayer Pereira

    2015-07-01

    Full Text Available Leaf-cutting ants of the genera Atta and Acromyrmex determine serious agricultural problems and live on symbiosis with Leucoagaricus gongylophorus. The aim of this study is to identify morphological and molecularly, as well as to verify the genotypic variability of the symbiotic fungus cultivated by A. heyeri and A. ambiguus from three different regions of the state of Rio Grande do Sul, Brazil. Fungus gardens were collected and fragments of mycelia were grown in selective medium. Total DNA was extracted and amplification of the ITS region was performed by PCR using universal primers. After DNA sequencing, the chromatograms were assembled and phylogenetic analyzes were performed by the Neighbor-Joining method. A total of six isolates of L. gongylophorus were obtained and their identities were confirmed by molecular analyses. Phylogenetic analysis of the ITS region showed a tree with two distinct groups regarding the fungus isolates from A. heiyeri and A. ambiguous. In this study, it was verified that A. heyeri and A. ambiguous, cultivate the same fungus. Additionally, the molecular marker used in this study showed variations in L. gongylophorus, evidencing two distinct branches in the phylogenetic tree, according to the ant species that cultivate L. gongylophorus. However, other studies involving the inclusion of a great number of isolates of L. gongylophorus, as well as the use of other molecular markers to validate the possible variations in the phylogenetic relationship of this symbiotic fungus are required.

  5. Minimal subspace rotation on the Stiefel manifold for stabilization and enhancement of projection-based reduced order models for the compressible Navier-Stokes equations

    CERN Document Server

    Balajewicz, Maciej; Dowell, Earl

    2015-01-01

    For a projection-based reduced order model (ROM) to be stable and accurate, the dynamics of the truncated subspace must be taken into account. This paper proposes an approach for stabilizing and enhancing projection-based fluid ROMs in which truncated modes are accounted for \\textit{a priori} via a minimal rotation of the projection subspace. Attention is focused on the full non-linear compressible Navier-Stokes equations in specific volume form as a step toward a more general formulation for problems with generic non-linearities. Unlike traditional approaches, no empirical turbulence modeling terms are required, and consistency between the ROM and the full order model from which the ROM is derived is maintained. Mathematically, the approach is formulated as a quadratic matrix program on the Stiefel manifold. The reproductive as well as predictive capabilities of the method are evaluated on several compressible flow problems, including a problem involving laminar flow over an airfoil with a high angle of atta...

  6. Radiometric 81Kr dating identifies 120,000 year old ice at Taylor Glacier, Antarctica

    CERN Document Server

    Buizert, Christo; Jiang, Wei; Purtschert, Roland; Petrenko, Vasilii V; Lu, Zheng-Tian; Mueller, Peter; Kuhl, Tanner; Lee, James; Severinghaus, Jeffrey P; Brook, Edward J

    2014-01-01

    We present the first successful 81Kr-Kr radiometric dating of ancient polar ice. Krypton was extracted from the air bubbles in four ~350 kg polar ice samples from Taylor Glacier in the McMurdo Dry Valleys, Antarctica, and dated using Atom Trap Trace Analysis (ATTA). The 81Kr radiometric ages agree with independent age estimates obtained from stratigraphic dating techniques with a mean absolute age offset of 6 +/- 2.5 ka. Our experimental methods and sampling strategy are validated by 1) 85Kr and 39Ar analyses that show the samples to be free of modern air contamination, and 2) air content measurements that show the ice did not experience gas loss. We estimate the error in the 81Kr ages due to past geomagnetic variability to be below 3 ka. We show that ice from the previous interglacial period (MIS 5e, 130-115 ka before present) can be found in abundance near the surface of Taylor Glacier. Our study paves the way for reliable radiometric dating of ancient ice in blue ice areas and margin sites where large samp...

  7. Influences of Pr and Ta doping concentration on the characteristic features of FTO thin film deposited by spray pyrolysis

    Institute of Scientific and Technical Information of China (English)

    G ¨uven Turgut; Adem Koc¸ yi˘git; Erdal S ¨onmez

    2015-01-01

    The Pr and Ta separately doped FTO (10 at.%F incorporated SnO2) films are fabricated via spray pyrolysis. The mi-crostructural, topographic, optical, and electrical features of fl uorine-doped TO (FTO) films are investigated as functions of Pr and Ta dopant concentrations. The x-ray diffraction (XRD) measurements reveal that all deposited films show polycrys-talline tin oxide crystal property. FTO film has (200) preferential orientation, but this orientation changes to (211) direction with Pr and Ta doping ratio increasing. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) anal-yses show that all films have uniform and homogenous nanoparticle distributions. Furthermore, morphologies of the films depend on the ratio between Pr and Ta dopants. From ultraviolet-visible (UV-Vis) spectrophotometer measurements, it is shown that the transmittance value of FTO film decreases with Pr and Ta doping elements increasing. The band gap value of FTO film increases only at 1 at.%Ta doping level, it drops off with Pr and Ta doping ratio increasing at other doped FTO films. The electrical measurements indicate that the sheet resistance value of FTO film initially decreases with Pr and Ta doping ratio decreasing and then it increases with Pr and Ta doping ratio increasing. The highest value of figure of merit is obtained for 1 at.%Ta-and Pr-doped FTO film. These results suggest that Pr-and Ta-doped FTO films may be appealing candidates for TCO applications.

  8. CONTINUING EDUCATION AND SCHOOL INCLUSION: POTENTIALITIES FOR THE CONSTRUCTION OF NEW POSTURES AND PRACTICES OF EDUCATORS FROM THE MUNICIPAL TEACHING NETWORK OF PRESIDENTE PRUDENTE

    Directory of Open Access Journals (Sweden)

    Simone Maria Carlos Gakiya

    2013-07-01

    Full Text Available The present work is a part of a research master's concerns continued training of teachers and school enrollment and consisted in analyzing the manifestations of educators articipating in the Continuing Education Course in Assistive Technology (AT-TA about their understandings, attitudes and practices regarding school inclusion of people with disabilities in municipal schools of Presidente Prudente/SP. The methodology adopted for data acquisition involved the reading of the documents produced by participants in the virtual learning environment (VLE-AVA TelEduc, because it is a course conducted through the modality of Distance Education (DE-EaD, and the application questionnaire and interview. The results revealed the personal dilemmas experienced with the process of inclusion expressed by feelings of insecurity, distrust, lack of professional training, fear of the new, the different, the influence of cultural, social and historical in conceptions, beliefs, values and pedagogical relationships; initial training that did not include the dilemmas experienced in the classroom; Public Policies, laws, guidelines not mobilized the occurrence of new attitudes and practices. In this study we sought to highlight the potential for the occurrence of the formation of new attitudes of educators face in the process of school inclusion.

  9. Antagonistic interactions between garden yeasts and microfungal garden pathogens of leaf-cutting ants.

    Science.gov (United States)

    Rodrigues, Andre; Cable, Rachel N; Mueller, Ulrich G; Bacci, Maurício; Pagnocca, Fernando C

    2009-10-01

    We investigate the diversity of yeasts isolated in gardens of the leafcutter ant Atta texana. Repeated sampling of gardens from four nests over a 1-year time period showed that gardens contain a diverse assemblage of yeasts. The yeast community in gardens consisted mostly of yeasts associated with plants or soil, but community composition changed between sampling periods. In order to understand the potential disease-suppressing roles of the garden yeasts, we screened isolates for antagonistic effects against known microfungal garden contaminants. In vitro assays revealed that yeasts inhibited the mycelial growth of two strains of Escovopsis (a specialized attine garden parasite), Syncephalastrum racemosum (a fungus often growing in gardens of leafcutter lab nests), and the insect pathogen Beauveria bassiana. These garden yeasts add to the growing list of disease-suppressing microbes in attine nests that may contribute synergistically, together with actinomycetes and Burkholderia bacteria, to protect the gardens and the ants against diseases. Additionally, we suggest that garden immunity against problem fungi may therefore derive not only from the presence of disease-suppressing Pseudonocardia actinomycetes, but from an enrichment of multiple disease-suppressing microorganisms in the garden matrix. PMID:19449210

  10. Broad Escovopsis-inhibition activity of Pseudonocardia associated with Trachymyrmex ants.

    Science.gov (United States)

    Meirelles, Lucas A; Mendes, Thaís D; Solomon, Scott E; Bueno, Odair C; Pagnocca, Fernando C; Rodrigues, Andre

    2014-08-01

    Attine ants maintain an association with antibiotic-producing Actinobacteria found on their integuments. Evidence supports these bacteria as auxiliary symbionts that help ants to defend the fungus gardens against pathogens. Using Pseudonocardia strains isolated from Trachymyrmex ants, we tested whether the inhibitory capabilities of such strains are restricted to Escovopsis parasites that infect gardens of this ant genus. Twelve Pseudonocardia strains were tested in in vitro bioassays against Escovopsis strains derived from fungus gardens of Trachymyrmex (n = 1) and leaf-cutting ants (n = 3). Overall, significant differences were observed in the mycelial growth among each Escovopsis strain in the presence of Pseudonocardia. Particularly, Escovopsis from Acromyrmex and Trachymyrmex were the most inhibited strains in comparison to Escovopsis isolated from Atta. This result suggests that Pseudonocardia isolated from Trachymyrmex possibly secrete antimicrobial compounds effective against diverse Escovopsis strains. The fact that Trachymyrmex ants harbour Pseudonocardia strains with broad spectrum of activity and its defensive role on attine gardens are discussed. PMID:24992532

  11. Enrichment and Broad Representation of Plant Biomass-Degrading Enzymes in the Specialized Hyphal Swellings of Leucoagaricus gongylophorus, the Fungal Symbiont of Leaf-Cutter Ants

    Energy Technology Data Exchange (ETDEWEB)

    Aylward, Frank O.; Khadempour, Lily; Tremmel, Daniel; McDonald, Bradon R.; Nicora, Carrie D.; Wu, Si; Moore, Ronald J.; Orton, Daniel J.; Monroe, Matthew E.; Piehowski, Paul D.; Purvine, Samuel O.; Smith, Richard D.; Lipton, Mary S.; Burnum-Johnson, Kristin E.; Currie, Cameron R.

    2015-08-28

    Leaf-cutter ants are prolific and conspicuous Neotropical herbivores that derive energy from specialized fungus gardens they cultivate using foliar biomass. The basidiomycetous cultivar of the ants, Leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. Gongylidia also contain lignocellulases that become concentrated in ant digestive tracts and are deposited within fecal droplets onto fresh foliar material as it is foraged by the ants. Although the enzymes concentrated by L. gongylophorus within gongylidia are thought to be critical to the initial degradation of plant biomass, only a few enzymes present in these hyphal swellings have been identified. Here we use proteomic methods to identify proteins present in the gongylidia of three Atta cephalotes colonies. Our results demonstrate that a diverse but consistent set of enzymes is present in gongylidia, including numerous lignocellulases likely involved in the degradation of polysaccharides, plant toxins, and proteins. Overall, gongylidia contained over three-quarters of all lignocellulases identified in the L. gongylophorus genome, demonstrating that the majority of the enzymes produced by this fungus for biomass breakdown are ingested by the ants. We also identify a set of 23 lignocellulases enriched in gongylidia compared to whole fungus garden samples, suggesting that certain enzymes may be particularly important in the initial degradation of foliar material. Our work sheds light on the complex interplay between leaf-cutter ants and their fungal symbiont that allows for the host insects to occupy an herbivorous niche by indirectly deriving energy from plant biomass.

  12. Leucoagaricus gongylophorus Produces Diverse Enzymes for the Degradation of Recalcitrant Plant Polymers in Leaf-Cutter Ant Fungus Gardens

    Energy Technology Data Exchange (ETDEWEB)

    Aylward, Frank O. [Univ. of Wisconsin, Madison, WI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burnum-Johnson, Kristin E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tringe, Susannah G. [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Teiling, Clotilde [Roche Diagnostics, Indianapolis, IN (United States); Tremmel, Daniel [Univ. of Wisconsin, Madison, WI (United States); Moeller, Joseph [Univ. of Wisconsin, Madison, WI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Scott, Jarrod J. [Univ. of Wisconsin, Madison, WI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Barry, Kerrie W. [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Piehowski, Paul D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nicora, Carrie D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Malfatti, Stephanie [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Monroe, Matthew E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Purvine, Samuel O. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Goodwin, Lynne A. [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Smith, Richard D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weinstock, George [Washington Univ. School of Medicine, St. Louis, MS (United States); Gerardo, Nicole [Emory Univ., Atlanta, GA (United States); Suen, Garret [Dept. of Energy Joint Genome Inst., Walnut Creek, CA (United States); Lipton, Mary S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Currie, Cameron R. [Univ. of Wisconsin, Madison, WI (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smothsonian Tropical Research Inst., Balboa (Panama)

    2013-06-12

    Plants represent a large reservoir of organic carbon comprised largely of recalcitrant polymers that most metazoans are unable to deconstruct. Many herbivores gain access to nutrients in this material indirectly by associating with microbial symbionts, and leaf-cutter ants are a paradigmatic example. These ants use fresh foliar biomass as manure to cultivate fungus gardens composed primarily of Leucoagaricus gongylophorus, a basidiomycetous symbiont that produces specialized hyphal swellings that serve as a food source for the host ant colony. Although leaf-cutter ants are conspicuous herbivores that contribute substantially to carbon turnover in Neotropical ecosystems, the process through which plant biomass is degraded in their fungus gardens is not well understood. Here we present the first draft genome of L. gongylophorus, and using genomic, metaproteomic, and phylogenetic tools we investigate its role in lignocellulose degradation in the fungus gardens of both Atta cephalotes and Acromyrmex echinatior leaf-cutter ants. We show that L. gongylophorus produces a diversity of lignocellulases in fungus gardens, and is likely the primary driver of plant biomass degradation in these ecosystems. We also show that this fungus produces distinct sets of lignocellulases throughout the different stages of biomass degradation, including numerous cellulases and laccases that may be playing an important but previously uncharacterized role in lignocellulose degradation. Our study provides a comprehensive analysis of plant biomass degradation in leaf-cutter ant fungus gardens and provides insight into the molecular dynamics underlying the symbiosis between these dominant herbivores and their obligate fungal cultivar.

  13. Discovery of defense- and neuropeptides in social ants by genome-mining.

    Directory of Open Access Journals (Sweden)

    Christian W Gruber

    Full Text Available Natural peptides of great number and diversity occur in all organisms, but analyzing their peptidome is often difficult. With natural product drug discovery in mind, we devised a genome-mining approach to identify defense- and neuropeptides in the genomes of social ants from Atta cephalotes (leaf-cutter ant, Camponotus floridanus (carpenter ant and Harpegnathos saltator (basal genus. Numerous peptide-encoding genes of defense peptides, in particular defensins, and neuropeptides or regulatory peptide hormones, such as allatostatins and tachykinins, were identified and analyzed. Most interestingly we annotated genes that encode oxytocin/vasopressin-related peptides (inotocins and their putative receptors. This is the first piece of evidence for the existence of this nonapeptide hormone system in ants (Formicidae and supports recent findings in Tribolium castaneum (red flour beetle and Nasonia vitripennis (parasitoid wasp, and therefore its confinement to some basal holometabolous insects. By contrast, the absence of the inotocin hormone system in Apis mellifera (honeybee, another closely-related member of the eusocial Hymenoptera clade, establishes the basis for future studies on the molecular evolution and physiological function of oxytocin/vasopressin-related peptides (vasotocin nonapeptide family and their receptors in social insects. Particularly the identification of ant inotocin and defensin peptide sequences will provide a basis for future pharmacological characterization in the quest for potent and selective lead compounds of therapeutic value.

  14. Discovery of defense- and neuropeptides in social ants by genome-mining.

    Science.gov (United States)

    Gruber, Christian W; Muttenthaler, Markus

    2012-01-01

    Natural peptides of great number and diversity occur in all organisms, but analyzing their peptidome is often difficult. With natural product drug discovery in mind, we devised a genome-mining approach to identify defense- and neuropeptides in the genomes of social ants from Atta cephalotes (leaf-cutter ant), Camponotus floridanus (carpenter ant) and Harpegnathos saltator (basal genus). Numerous peptide-encoding genes of defense peptides, in particular defensins, and neuropeptides or regulatory peptide hormones, such as allatostatins and tachykinins, were identified and analyzed. Most interestingly we annotated genes that encode oxytocin/vasopressin-related peptides (inotocins) and their putative receptors. This is the first piece of evidence for the existence of this nonapeptide hormone system in ants (Formicidae) and supports recent findings in Tribolium castaneum (red flour beetle) and Nasonia vitripennis (parasitoid wasp), and therefore its confinement to some basal holometabolous insects. By contrast, the absence of the inotocin hormone system in Apis mellifera (honeybee), another closely-related member of the eusocial Hymenoptera clade, establishes the basis for future studies on the molecular evolution and physiological function of oxytocin/vasopressin-related peptides (vasotocin nonapeptide family) and their receptors in social insects. Particularly the identification of ant inotocin and defensin peptide sequences will provide a basis for future pharmacological characterization in the quest for potent and selective lead compounds of therapeutic value. PMID:22448224

  15. Electrochemistry on binary valve metal combinatorial libraries: niobium-tantalum thin films

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • A Nb-Ta wide spread (89 at.%) co-sputtered thin film library was characterized. • Microstructure and crystallography of Nb-Ta alloys were mapped along the composition. • Scanning droplet cell microscopy was used for mapping of electrochemical properties. • Oxide growth (<2.6 nm/V) and dielectric constants (<50) were analyzed for each alloy. • Type n semiconducting behavior was found and mixed oxide composition was analyzed. - Abstract: A Nb-Ta thin film compositional spread obtained from a co-sputtering process was analysed. The microstructure and crystallographic investigations revealed the presence of a compositional threshold at Nb-60 at.%Ta where the change from tetragonal to cubic symmetry was evidenced by a mixed tetragonal-cubic phase. The electrochemical properties of the anodic oxides were studied via cyclic voltammetry and the oxide formation factors were mapped along the entire compositional spread. Values ranging from 1.8 nm·V−1 at the Ta-rich side to 2.6 nm·V−1 at the Nb-rich side of the library were measured. All Nb-Ta mixed anodic oxides were found to exhibit a type-n semiconducting behaviour as evidenced by Mott-Schottky analysis. The chemical composition of the surface anodic oxides differed from the composition of the parent metal alloys and no clear trend could be identified regarding their mismatch

  16. Konsep Ilmu dalam Islam

    Directory of Open Access Journals (Sweden)

    Achmad Reza Hutama al-Faruqi

    2015-12-01

    Full Text Available Concept of science in Islam has its own universal dimension, metaphysic and empiric, and diffenrent from sciences came from Western worldview which limited in empiric dimension. It will be in the case that the concept of science in Islam is one of integral part of Islamic worldview; so that it has its own characteristics differed from another concept of science in other civilizations. Science according to Islamic worldview is not only cover substance of knowledge, but becomes important element in civilization as well. Related to the important of position of science, number of scholar such as Ibnu Khaldun, Imam al Ghazali, or Syed Muhammad Naquib al-Attas gave several features of science to know which one has higher priority, to be associated with how the concept of science in Islam decided later. From the discussion offered by the scholars, it will be understood that science in Islam not only encompasses theology and law, but also there is a row of other sciences such as physics, biology, and so forth need to be studied. The acquisition method of each branch of sciences have their own approach, both of internal and external sense, khabar s}a>diq, and the third is intellect. A Muslim should solidly hold the Islamic tradition and not too impressed with the tradition of Western scholarly even it looks more attractive.

  17. Methodology for the insecticide potential evaluation of forest species

    International Nuclear Information System (INIS)

    The flora diversity of Colombia has an enormous potential in the rational use of its forest resources. Trees with biocides effects to pest control and diseases need to be investigated. The objective of this research was to develop a methodology with low costs, easy application and quick results. The methodology employed was as follows: selection of tree species based on bibliography, ancestral reports and personal observations. The process was as follows: field collection of plants, preparation of plants extracts, and test with Artemia Salina, leach to detect biological activity of the extracts using LC50. Bioassays with those extract more promising (LC50 less than 1000 ppm). The methodology was employed with 5 forest tree species: Guarea guidonia (L.) Sleumer and Trichia hirta L. (Meliaceae), machaerium moritzianum Benth. (Fabaceae), Swinglea glutinosa Merrill. (Rutaceae) and Mammea americana L. (Clusiaceae). Using Artemia salina Leach as indicator of biocidal potential, two species were selected as the most promising, those were: Swinglea glutinosa Merril and Machaerium moritzianum Benth. In addition bioassays were made to evaluate fagoinhibition on Atta cephalotes (L.) and control of Alconeura. This methodology is recommended for this kind of research

  18. Methodology to evaluate the insecticide potential of forest tree species

    International Nuclear Information System (INIS)

    The flora diversity of Colombia has an enormous potential in the rational use of its forest resources. Trees with biocidal effects to control pests and diseases need to be investigated. The objective of this research was to develop a methodology with low costs, easy application and quick results. The methodology employed was as follows: selection of tree species based on bibliography, ancestral reports and personal observations. The process was as follows: field collection of plants, preparation of plants extracts and test with Artemia salina Leach to detect biological activity of the extracts using LC50. Bioassays with those extract more promising (LC50 less than 1000 ppm) Determination of active compounds. The methodology was employed with 5 forest tree species: guarea guidonia (L) Sleumer and trichia hirta L. (Meliaceae), Machaerium Moritzianum Benth. (Fabaceae), Swinglea glutinosa Merrill (rutaceae) and Mammea americana L. (Clusiaceae). Using Artemia salina Leach as indicator of biocidal potential, two species were selected as the most promising, those were: Swinglea glutinosa Merril and Machaerium moritzianum Benth. In addition bioassays were made to evaluate fagoinhibition on Atta cephalotes (L.) (Hym: Formicidae) and control of Alconeura. This methodology is recommended for this kind of research

  19. Insects associated with tropical foliage produced in the coffee growing region of Colombia

    Directory of Open Access Journals (Sweden)

    Luis F. Aristizábal

    2013-09-01

    Full Text Available We conducted a survey of insects and pest management practices on 34 farms growing ornamental tropical foliage plants in the central coffee region of Colombia over two years. Tropical foliage provided habitat for a diverse range of insects. In total, phytophagous or detritivorous insects from six orders, 40 families and 62 genera were collected. The most common were Hemiptera (29 genera from 16 families, followed by Coleoptera (17 genera from 4 families, Diptera (5 genera from 5 families, Lepidoptera (5 genera from 4 families, Hymenoptera (3 genera from 2 families and Orthoptera (2 genera from 2 families. The most common phytophagous species were leaf cutting ants (Atta and Acromyrmex spp., leaf beetles (Chrysomelidae, leafhoppers (Cicadellidae, stinkbugs (Pentatomidae, squash bugs (Coreidae, tree hoppers (Membracidae and plant hoppers (Fulgoridae. Beneficial insects identified from tropical foliage included predators and parasitoids amongst 5 orders, 12 families and 22 genera. The most abundant were predators among the Coccinellidae, Chrysopidae, Reduviidae, Lycidae and Formicidae but only low numbers of parasitoids (Ichneumonidae, Braconidae and Tachinidae were collected. A pest management questionnaire given to growers revealed a preponderance of reliance on broad spectrum insecticides with a smaller number of growers (approximately one third also using some biological control methods. Our survey contributes basic information regarding diversity of Neotropical insects associated with ornamental foliage plants.

  20. Recognition of base pair inversions in duplex by chimeric (alpha,beta) triplex-forming oligonucleotides.

    Science.gov (United States)

    Timofeev, Edward N; Goryaeva, Baira V; Florentiev, Vladimir L

    2006-10-01

    DNA recognition by triplex-forming oligonucleotides (TFOs) is usually limited by homopurine-homopyrimidine sequence in duplexes. Modifications of the third strand may overcome this limitation. Chimeric alpha-beta TFOs are expected to form triplex DNA upon binding to non-regular sequence duplexes. In the present study we describe binding properties of chimeric alpha-beta oligodeoxynucleotides in the respect to short DNA duplexes with one, three, and five base pair inversions. Non-natural chimeric TFO's contained alpha-thymidine residues inside (GT) or (GA) core sequences. Modified residues were addressed to AT/TA inversions in duplexes. It was found in the non-denaturing gel-electrophoresis experiments that single or five adjacent base pair inversions in duplexes may be recognized by chimeric alpha-beta TFO's at 10 degrees C and pH 7.8. Three dispersed base pair inversions in the double stranded DNA prevented triplex formation by either (GT) or (GA) chimeras. Estimation of thermal stability of chimeric alpha-beta triplexes showed decrease in T(m) values as compared with unmodified complexes. PMID:16928141

  1. La cour et les sciences : naissance des politiques scientifiques dans les cours européennes aux XVIIe et XVIIIe siècles

    OpenAIRE

    Aillagon, Jean-Jacques; Blay, Michel; Sergei S. Demidov; Fouilleron, Thomas; Godfroy-de Borms, Marion F.; Gołąbek, Marta; Grell, Chantal; Halleux, Robert; Knobloch, Eberhard Heinrich; Leitão, Henrique; Le Flem, Jean-Paul; McClellan III, James E.; Montègre, Gilles; Mormiche, Pascale; Nicolaïdis, Efthymios

    2011-01-01

    La cour, siège du pou­voir et lieu de concen­tra­tion des capi­taux, a tou­jours sou­tenu la recher­che scien­ti­fi­que tan­dis que cette der­nière devait ser­vir les inté­rêts géné­raux du pays et la gloire de son sou­ve­rain. Dans ce col­lo­que, il s’agira essen­tiel­le­ment d’étudier les poli­ti­ques scien­ti­fi­ques volon­ta­ris­tes ou non des États euro­péens sous l’Ancien Régime en s’atta­chant par­ti­cu­liè­re­ment à la recher­che « fon­da­men­tale » et à la recher­che « utile » (amé­l...

  2. The EAGLE project: Simulating the evolution and assembly of galaxies and their environments

    CERN Document Server

    Schaye, Joop; Bower, Richard G; Furlong, Michelle; Schaller, Matthieu; Theuns, Tom; Vecchia, Claudio Dalla; Frenk, Carlos S; McCarthy, I G; Helly, John C; Jenkins, Adrian; Rosas-Guevara, Y M; White, Simon D M; Baes, Maarten; Booth, C M; Camps, Peter; Navarro, Julio F; Qu, Yan; Rahmati, Alireza; Sawala, Till; Thomas, Peter A; Trayford, James

    2014-01-01

    We introduce the Virgo Consortium's EAGLE project, a suite of hydrodynamical simulations that follow the formation of galaxies and black holes in representative volumes. We discuss the limitations of such simulations in light of their finite resolution and poorly constrained subgrid physics, and how these affect their predictive power. One major improvement is our treatment of feedback from massive stars and AGN in which thermal energy is injected into the gas without the need to turn off cooling or hydrodynamical forces, allowing winds to develop without predetermined speed or mass loading factors. Because the feedback efficiencies cannot be predicted from first principles, we calibrate them to the z~0 galaxy stellar mass function and the amplitude of the galaxy-central black hole mass relation, also taking galaxy sizes into account. The observed galaxy mass function is reproduced to $\\lesssim 0.2$ dex over the full mass range, $10^8 < M_*/M_\\odot \\lesssim 10^{11}$, a level of agreement close to that atta...

  3. Evolution of cold-tolerant fungal symbionts permits winter fungiculture by leafcutter ants at the northern frontier of a tropical ant-fungus symbiosis.

    Science.gov (United States)

    Mueller, Ulrich G; Mikheyev, Alexander S; Hong, Eunki; Sen, Ruchira; Warren, Dan L; Solomon, Scott E; Ishak, Heather D; Cooper, Mike; Miller, Jessica L; Shaffer, Kimberly A; Juenger, Thomas E

    2011-03-01

    The obligate mutualism between leafcutter ants and their Attamyces fungi originated 8 to 12 million years ago in the tropics, but extends today also into temperate regions in South and North America. The northernmost leafcutter ant Atta texana sustains fungiculture during winter temperatures that would harm the cold-sensitive Attamyces cultivars of tropical leafcutter ants. Cold-tolerance of Attamyces cultivars increases with winter harshness along a south-to-north temperature gradient across the range of A. texana, indicating selection for cold-tolerant Attamyces variants along the temperature cline. Ecological niche modeling corroborates winter temperature as a key range-limiting factor impeding northward expansion of A. texana. The northernmost A. texana populations are able to sustain fungiculture throughout winter because of their cold-adapted fungi and because of seasonal, vertical garden relocation (maintaining gardens deep in the ground in winter to protect them from extreme cold, then moving gardens to warmer, shallow depths in spring). Although the origin of leafcutter fungiculture was an evolutionary breakthrough that revolutionized the food niche of tropical fungus-growing ants, the original adaptations of this host-microbe symbiosis to tropical temperatures and the dependence on cold-sensitive fungal symbionts eventually constrained expansion into temperate habitats. Evolution of cold-tolerant fungi within the symbiosis relaxed constraints on winter fungiculture at the northern frontier of the leafcutter ant distribution, thereby expanding the ecological niche of an obligate host-microbe symbiosis. PMID:21368106

  4. KONTRIBUSI PEMIKIRAN ISLAM KONTEMPORER BAGI PENGEMBANGAN FILSAFAT ILMU-ILMU KEISLAMAN

    Directory of Open Access Journals (Sweden)

    Fuad Ramly

    2014-12-01

    Full Text Available Pengembangan Filsafat Ilmu-ilmu Keislaman dapat dilakukan dengan merumuskan kembali landasan ontologis, landasan epistemologis, dan landasan aksiologis ilmu yang bersumber dari kontribusi pemikiran Nasr, al-Attas, dan Sardar. Landasan ontologis tersebut menentukan wilayah objek kajian Ilmu-ilmu Keislaman, yang meliputi aspek-aspek metafisika dan empiris. Landasan epistemologis mengakomodir keragaman (pluralitas metodologis (berbagai prosedur atau cara mengkaji ilmu, sesuai dengan kebutuhan intelektual masyarakat Islam. Landasan aksiologis mengarahkan dan menuntun pemahaman ontologis dan epistemologis tersebut sesuai dengan nilai-nilaidasar Islam. Berdasarkan ketiga landasan tersebut, pengembangan Filsafat Ilmu-ilmu Keislaman dapat dilakukan secara terpadu (integratif, tidak hanya dengan menumbuhkan kesadaran historis untuk menggali khazanah kemajuan intelektual Islam masa lalu, tetapi sekaligus juga dengan merespon kemajuan-kemajuan metodologi masa kini yang relevan dengan nilai-nilai intelektual Islam yang kekal dan universal.Kata kunci: Pemikiran Islam Kontemporer; landasan filosofis; Filsafat Ilmu-ilmu Keislaman.

  5. Correlation between virulence and genetic structure of Escovopsis strains from leaf-cutting ant colonies in Costa Rica.

    Science.gov (United States)

    Wallace, Diego E Elizondo; Asensio, Juan G Vargas; Tomás, Adrián A Pinto

    2014-08-01

    Leaf-cutting ants (genera Atta and Acromyrmex) cultivate a specialized fungus for food in underground chambers employing cut plant material as substrate. Parasitism occurs in this agricultural system and plays an important role in colony fitness. The microfungi Escovopsis, a specialized mycoparasite of the fungal cultivar, is highly prevalent among colonies. In this study, we tested the antagonistic activity of several Escovopsis strains from different geographical areas in Costa Rica. We employed a combination of laboratory tests to evaluate virulence, including pure culture challenges, toxicity to fungus garden pieces and subcolony bioassays. We also performed a phylogenetic analysis of these strains in order to correlate their virulence with the genetic structure of this population. The bioassays yielded results consistent between each other and showed significant differences in antagonistic activity among the parasites evaluated. However, no significant differences were found when comparing the results of the bioassays according to the source of the ants' fungal cultivar. The phylogenetic analyses were consistent with these results: whilst the fungal cultivar phylogeny showed a single clade with limited molecular variation, the Escovopsis phylogeny yielded several clades with the most virulent isolates grouping in the same well-supported clade. These results indicate that there are Escovopsis strains better suited to establish their antagonistic effect, whilst the genetic homogeneity of the fungal cultivars limits their ability to modulate Escovopsis antagonism. These findings should be taken into consideration when evaluating the potential of Escovopsis isolates as biocontrol agents for this important agricultural pest in the Neotropics. PMID:24836623

  6. Emission of ions and charged soot particles by aircraft engines

    Directory of Open Access Journals (Sweden)

    A. Sorokin

    2003-01-01

    Full Text Available In this article, a model which examines the formation and evolution of chemiions in an aircraft engine is proposed. This model which includes chemiionisation, electron thermo-emission, electron attachment to soot particles and to neutral molecules, electron-ion and ion-ion recombination, ion-soot interaction, allows the determination of the ion concentration at the exit of the combustor and at the nozzle exit of the engine. It also allows the determination of the charge of the soot particles. For the engine considered, the upper limit for the ion emission index EIi is of the order of (2-5 x1016 ions/kg-fuel if ion-soot interactions are ignored and the introduction of ion-soot interactions lead about to a 50% reduction. The results also show that most of the soot particles are either positively or negatively charged, the remaining neutral particles representing approximately 20% of the total particles. A comparison of the model results with the available ground-based experimental data obtained on the ATTAS research aircraft engines during the SULFUR experiments (Schumann, 2002 shows an excellent agreement.

  7. Synergistic effects of three Piper amides on generalist and specialist herbivores.

    Science.gov (United States)

    Dyer, L A; Dodson, C D; Stireman, J O; Tobler, M A; Smilanich, A M; Fincher, R M; Letourneau, D K

    2003-11-01

    The tropical rainforest shrub Piper cenocladum, which is normally defended against herbivores by a mutualistic ant, contains three amides that have various defensive functions. While the ants are effective primarily against specialist herbivores, we hypothesized that these secondary compounds would be effective against a wider range of insects, thus providing a broad array of defenses against herbivores. We also tested whether a mixture of amides would be more effective against herbivores than individual amides. Diets spiked with amides were offered to five herbivores: a naïve generalist caterpillar (Spodoptera frugiperda), two caterpillar species that are monophagous on P. cenocladum (Eois spp.), leaf-cutting ants (Atta cephalotes), and an omnivorous ant (Paraponera clavata). Amides had negative effects on all insects, whether they were naïve, experienced, generalized, or specialized feeders. For Spodoptera, amide mixtures caused decreased pupal weights and survivorship and increased development times. Eois pupal weights, larval mass gain, and development times were affected by additions of individual amides, but increased parasitism and lower survivorship were caused only by the amide mixture. Amide mixtures also deterred feeding by the two ant species, and crude plant extracts were strongly deterrent to P. clavata. The mixture of all three amides had the most dramatic deterrent and toxic effects across experiments, with the effects usually surpassing expected additive responses, indicating that these compounds can act synergistically against a wide array of herbivores. PMID:14682530

  8. Krypton-81 case study: the Nubian aquifer, Egypt. Chapter 14

    International Nuclear Information System (INIS)

    The Nubian aquifer of north-east Africa is one of the world’s largest fresh groundwater resources (∼150 000 km3). An area in the Western Desert of Egypt, for which a number of earlier studies provided sufficient background data on the Nubian aquifer, was selected for the first application of the atom trap trace analysis (ATTA) method (Section 5.4.3) for measurement of 81Kr in groundwater. This area has relatively simple geology, potential for containing very old groundwater, and favourable characteristics for comparison of the 81Kr and 36Cl methods (Sturchio et al. (2004)). Before this work, little evidence regarding absolute groundwater residence time in the N ubian aquifer was available. Estimates of groundwater age in the range of 0.54 × 106–1.58 × 106 a had been obtained from He/Ar ratios (Himida (1967) [729]). A large number of 14C data had been obtained for the Nubian aquifer waters in Egypt (Fröhlich et al. (2007) [730]; Sonntag et al. (1979) [731]). Chlorine-36 data indicated possible residence times of up to ∼9 × 105 a (unpublished data).

  9. 3ynamic Adsorption of Microwave Modified Attapulgite on Micro-polluted Phenol Wastewater

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    [Objective] The paper was to study the dynamic adsorption of microwave modified attapulgite on micro-polluted phenol wastewater. [Method] Cetyl trimethyl ammonium bromide (CATB) modified attapulgite was used to modify attapulgite, and conducted dynamic test on micro-polluted phenol wastewater. The dynamic charac- teristics of phenol removal were also studied. [Result] Attapulgite modified by CATB has strong adsorption ability on phenol in micro-polluted water, the phenol removal rate increased with the decrease of flow rate of wastewater. When pH value was 6- 8, phenol concentration in wastewater was 17.74 mg/L, flow rate was 2 m/s and ad- sorption time was 25 rain, the removal rate reached 93.07%. The modified atta- pulgite could be regenerated with alkali, and its adsorption ability after regeneration had no obvious decline. The dynamic adsorption process of phenol accorded with the first-order kinetic equation. [Conclusion] The study provided basis for further study on "organic matter removal in wastewater.

  10. Aircraft exhaust aerosol formation and growth

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.C.; Miake-Lye, R.C.; Anderson, M.R.; Kolb, C.E. [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics

    1997-12-31

    Aerosol formation and growth in the exhaust plume of the ATTAS aircraft at an altitude of approximately 9 km, burning fuels with 2 ppmm sulfur (`low`) and 266 ppmm (`high`) sulfur has been modeled using an aerosol dynamics model for nucleation, vapor condensation and coagulation, coupled to a 2-dimensional, axisymmetric flow code to treat plume dilution and turbulent mixing. For both the `low` and `high` sulfur fuels, approximately 60% of the available water had condensed within the first 200 m downstream of the exhaust exit. The contrail particle diameters ranged between 0.4 to 1.6 {mu}m. However, the size distributions as a function of radial position for the `low` sulfur plume were broader than the corresponding distributions for the `high` sulfur plume. The model results indicate for a fuel sulfur mass loading of 2 ppmm, sulfuric acid remains a viable activating agent and that the differences in the contrail particle size distributions for sulfur mass loadings between 2 ppmm and 260 ppmm would be difficult to detect. (author) 12 refs.

  11. Research on Students’ Condition and Measures of Developing Students’ Employment Competence of Applied Undergraduate Colleges---Take Longdong University as an Example%应用型本科院校生源状况与就业能力培养路径分析--以陇东学院为例

    Institute of Scientific and Technical Information of China (English)

    张婷婷

    2015-01-01

    Take the example of Longdong University , this thesis analyses the background of the students who attend applied undergraduate colleges as well as their studies at the school , their job in turn it atta-ches importance to college general education which is the foundation of education .It also stresses the im-portance of implementing early career planing in classrooms from different dimensions .It proposes that more cognitive courses on majors and relevant occupations should be offered at the college and the focus of the school should be on improving students'ability within their professional studies .%以陇东学院为例分析应用型本科院校的生源状况、就业现状以及就业诉求等,对人才培养理念及教学过程中存在的不足进行分析,倡导重视通识教育的基础作用,有效提升职业生涯规划教育的效果,增设专业和职业认知教育环节,描绘以能力培养为主线的专业教育等培养思路。

  12. Turbulent mixing driven by mean-flow shear and internal gravity waves in oceans and atmospheres

    CERN Document Server

    Baumert, Helmut Z

    2012-01-01

    This study starts with balances deduced by Baumert and Peters (2004, 2005) from results of stratified-shear experiments made in channels and wind tunnels by Itsweire (1984) and Rohr and Van Atta (1987), and of free-decay experiments in a resting stratified tank by Dickey and Mellor (1980). Using a modification of Canuto's (2002) ideas on turbulence and waves, these balances are merged with an (internal) gravity-wave energy balance presented for the open ocean by Gregg (1989), without mean-flow shear. The latter was augmented by a linear (viscous) friction term. Gregg's wave-energy source is interpreted on its long-wave spectral end as internal tides, topography, large-scale wind, and atmospheric low-pressure actions. In addition, internal eigen waves, generated by mean-flow shear, and the aging of the wave field from a virginal (linear) into a saturated state are taken into account. Wave packets and turbulence are treated as particles (vortices, packets) by ensemble kinetics so that the loss terms in all thre...

  13. Analýza a demonstrace vybraných L2 útoků

    OpenAIRE

    Lomnický, Marek

    2009-01-01

    Tato diplomová práce se zabývá principy, praktickou proveditelností a zabezpečením proti čtyřem v současnosti používaným útokům v LAN sítích: CAM Table Overflow sloužícího k odchytu dat v přepínaných sítích, ARP Man-in-the-Middle schopného přesměrovat a modifikovat data a dvěma variantám útoku VLAN Hopping dovolujícího útočníkovi zasílat a odchytávat data z VLAN, ke kterým nemá oficiálně přístup. This MSc Thesis focuses on principles, practical performability and security against four atta...

  14. Identificação de microssatélites para o mamoeiro por meio da exploração do banco de dados de DNA Identification of microsatellites for papaya by DNA data bank exploration

    Directory of Open Access Journals (Sweden)

    Eder Jorge de Oliveira

    2008-09-01

    Full Text Available Os marcadores microssatélites são ferramentas úteis em diversas análises genéticas em plantas. No caso do mamoeiro (Carica papaya L., poucos locos de microssatélites foram descritos até o momento. Assim, o objetivo deste trabalho foi explorar a base de dados do GenBank / NCBI (National Center of Biotechnoloy Information à procura de microssatélites de mamoeiro, visando a seu futuro uso em estudos genéticos e moleculares aplicados ao melhoramento genético. As seqüências foram obtidas no GenBank / NCBI, no formato FASTA, e analisadas para a presença de microssatélites com um mínimo de 20; 7 e 5 repetições dos motivos de mono-, di- e trinucleotídeos, respectivamente, e acima de 4 repetições para tetra- e pentanucleotídeos. Seqüências com mais de 90% de similaridade foram consideradas redundantes e, portanto, eliminadas das análises. Foram analisadas 44.591 seqüências, das quais 3.180 foram não-redundantes e apresentaram 3.947 microssatélites. Desse total, 3.587 foram classificados como microssatélites perfeitos, 8 imperfeitos, 65 interrompidos, 239 compostos-perfeitos, 8 compostos-imperfeitos e 40 compostos-interrompidos. As repetições de di- e trinucleotídeos representaram 65,7 e 14,4% do total de seqüências analisadas, respectivamente. Somente os motivos do tipo AT/TA representaram 44,1% dos microssatélites encontrados. Os motivos mais comuns de tri-, tetra- e pentanucleotídeos foram AAT, AATT e TTTAA, respectivamente. Observou-se que, nas seqüências disponíveis, o genoma do mamoeiro apresenta, em média, um microssatélite a cada 5,65 kb.Microsatellites markers are a useful tool in much plant genetic analysis. Currently, few microsatellites loci have been reported in Carica papaya L.. Therefore, the objective of this study was accomplishing a search for microsatellites in the public available - GenBank / NCBI (National Center of Biotechnology Information, aiming the future use in molecular and genetic

  15. Patterns of diversity and abundance of fungus-growing ants (Formicidae: Attini in areas of the Brazilian Cerrado Padrões de diversidade e abundância de formigas cultivadoras de fungo (Formicidade: Attini em áreas do Cerrado Brasileiro

    Directory of Open Access Journals (Sweden)

    Heraldo L. Vasconcelos

    2008-09-01

    Full Text Available Fungus-growing ants (tribe Attini are characteristic elements of the New World fauna. However, there is little information on the patterns of diversity, abundance, and distribution of attine species in their native ecosystems, especially for the so-called "lower" genera of the tribe. A survey of attine ant nests (excluding Atta Fabricus, 1804 and Acromyrmex Mayr, 1865 was conducted in a variety of savanna and forest habitats of the Cerrado biome near Uberlândia, Brazil. In total, 314 nests from 21 species of nine genera were found. Trachymyrmex Forel, 1893 was the most diverse genus with 10 species. Eighteen species were found in the savannas, including Mycetagroicus cerradensis Brandão & Mayhé-Nunes, 2001, a species from a recently-described genus of Attini, whereas in the forests only 12 species were found. Forest and savannas support relatively distinct faunas, each with a number of unique species; the species present in the forest habitats did not represent a nested subset of the species found in the savannas. Furthermore, although many species were common to both types of vegetation, their abundances were quite different. The density of attine nests is relatively high at some sites, exceeding an estimated 4,000 nests per hectare. In this sense, attine ants can be regarded as prevalent invertebrate taxa in the Brazilian Cerrado.As formigas cultivadoras de fungos (tribo Attini são exclusivas da fauna do Novo Mundo. Entretanto, existem poucas informações sobre os padrões de diversidade, abundância e distribuição das espécies de Attini em seus ecossistemas nativos, em especial para os gêneros menos derivados desta tribo. Um levantamento de ninhos de Attini (excluindo Atta Fabricius, 1804 e Acromyrmex Mayr, 1865 foi realizado em diversos ambientes savânicos e de floresta do bioma Cerrado próximos à Uberlândia, Brasil. Encontramos 314 ninhos de 21 espécies pertencentes a nove gêneros da tribo. Trachymyrmex Forel, 1893 foi o g

  16. O jardim de fungo atua como um molde para a construção das câmaras em formigas cortadeiras? Fungus garden acts as a template for the construction of chambers in ants?

    Directory of Open Access Journals (Sweden)

    Roberto da Silva Camargo

    2013-04-01

    Full Text Available Os ninhos adultos das formigas cortadeiras (gênero Atta e Acromyrmex são compostos de milhares de câmaras subterrâneas, as quais abrigam o jardim de fungo, lixo e a população desses insetos. Entretanto, como as câmaras são construídas? Para responder essa questão, nós hipotetizamos que o jardim de fungo atua como um molde para a construção das câmaras. Assim, foram utilizadas 20 colônias de 6 meses de idade, divididas em quatro séries experimentais: padrão (quantidade normal de jardim de fungo; metade de jardim de fungo; dobro de jardim de fungo e sem jardim de fungo (Testemunha. As variáveis estudadas foram: parâmetros morfológicos das estruturas (túneis e câmara formada; fluxo das atividades das operárias; volume de solo escavado. Como se esperava, o jardim de fungo atua como um molde para a construção das câmaras em formigas cortadeiras. Os resultados foram: o tratamento sem jardim de fungo não apresentou nenhuma câmara, apenas túneis, em contraposição às demais séries experimentais que apresentaram no mínimo 2 câmaras, com dimensões similares; o fluxo das operárias carregando pellet de solo por minuto durante as 72 horas diferiu estatisticamente entre as séries experimentais e, finalmente, o volume do solo escavado foi resultado da taxa de escavação das operárias, diferindo estatisticamente entre as séries experimentais. Os resultados corroboram a hipótese de que o jardim de fungo atua como um molde para a construção da câmara. A ausência de uma estrutura funcional como uma câmara, quando o jardim de fungo está ausente, comprova a hipótese.Adult nests of leaf cutting ants (genus Atta and Acromyrmex are composed of thousands of underground chambers, which harbor the fungus garden, garbage and their population. However, how the chambers are constructed? To answer this question, we hypothesized that the fungus garden acts as a template for the chambers construction. Thus, we used 20 colonies of

  17. 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

    Directory of Open Access Journals (Sweden)

    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

  18. Combate sistemático de formigas-cortadeiras com iscas granuladas, em eucaliptais com cultivo mínimo Systematic control of leaf-cutting ants in areas with eucalyptus stands under minimum cultivation system

    Directory of Open Access Journals (Sweden)

    Ronald Zanetti

    2003-06-01

    Full Text Available Avaliou-se a eficiência do combate sistemático de formigas-cortadeiras em áreas de reforma de eucalipto com cultivo mínimo, na Celulose Nipo-Brasileira S.A., em Belo Oriente, Minas Gerais, de setembro a dezembro de 1996. Os tratamentos consistiram na aplicação de uma isca granulada com sulfluramida (0,3% de forma sistemática, a granel ou com microporta-iscas, na dosagem de 5 g a cada 6 m² e 10 g a cada 12 m², respectivamente. A mortalidade das colônias de formigas-cortadeiras foi avaliada 30 dias após a aplicação da isca. Foram encontradas até 396,3, 285,2, 59,3, 55,6, 29,6 e 14,8 colônias de Mycocepurus goeldii, Sericomyrmex sp., Acromyrmex subterraneus molestans, Atta spp., Acromyrmex balzani e Acromyrmex niger (Hymenoptera: Formicidae por hectare, respectivamente. A eficiência da isca granulada no combate sistemático variou com o método empregado e com a espécie de formiga-cortadeira. A maior eficiência foi obtida para A. subterraneus molestans, com 69,2% de suas colônias mortas com a isca aplicada a granel e 62,5% com microporta-iscas, o que indica que a distribuição entre dois pontos com isca nos plantios de eucalipto foi maior que a área de forrageamento das formigas-cortadeiras encontradas e, ou, que a dosagem aplicada por ponto foi insuficiente.The efficiency of a systematic application of baits against leaf-cutting ants was evaluated in a eucalypus plantation under a minimum cultivation system, in areas owned by Celulose Nipo-Brasileira S.A. (CENIBRA, in Belo Oriente, Minas Gerais, Brazil, from September to December 1996. Treatments consisted of applying a granulated bait with sulfluramide (0.3% in a systematic manner in bulk and plastic bags at a dose of five grams every 6 m² (T1 and 10 grams at each 12 m² (T2. Mortality of colonies of leaf-cutting ants was evaluated 30 days after bait application. A. maximum of 396.3; 285.2; 59.3; 55.6; 29.6 and 14.8 colonies of Mycocepurus goeldii, Sericomyrmex sp

  19. Clinical significance of vascular endothelial growth factor in hepatitis C related hepatocellular carcinoma in Egyptian patients

    Directory of Open Access Journals (Sweden)

    Atta MM

    2016-06-01

    Full Text Available Mohamed Magdi El-Sadek Ali Atta,1,2 Hazem Mahmoud Atta,3,4 Magdy Abdel-Mawgoud Gad,2 Laila Ahmad Rashed,4 Ebada M Said,2 Sharaf El-Sayed Ali Hassanien,2 Ahmed O Kaseb5 1Department of Medicine, Rabigh Faculty of Medicine, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia; 2Department of Hepatology, Gastroenterology and Infectious Diseases, Faculty of Medicine, Benha University, Benha, Egypt; 3Department of Clinical Biochemistry, Rabigh Faculty of Medicine, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia; 4Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Cairo University, Cairo, Egypt; 5Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA Background and aims: Several angiogenic factors are involved in the development and progression of hepatocellular carcinoma (HCC, a hypervascular tumor. Vascular endothelial growth factor (VEGF is a primary driving force for angiogenesis, and its overexpression has been reported in HCC. However, the significance of plasma and tissue VEGF levels in HCC in Egyptian patients with chronic hepatitis C (CHC infection is understudied. The aim of this study was to evaluate the role of VEGF (measured in plasma and liver tissue in patients with hepatitis C virus-related HCC and to assess its significance in the diagnosis and prognosis of HCC. Materials and methods: A total of 90 subjects were studied. Among 90 subjects, 60 with CHC were examined and were subdivided into two groups: 30 patients with CHC-related HCC (HCC group and 30 patients with CHC without HCC (non-HCC group. Thirty apparently healthy subjects served as the control group. VEGF was estimated in plasma by enzyme-linked immunosorbent assay and its expression in liver tissue was evaluated by real-time polymerase chain reaction. VEGF expression level and its relationship to tumor parameters, patients' liver function profile, and patients' clinical

  20. Krypton-81 in groundwater of the Culebra Dolomite near the Waste Isolation Pilot Plant, New Mexico.

    Science.gov (United States)

    Sturchio, Neil C; Kuhlman, Kristopher L; Yokochi, Reika; Probst, Peter C; Jiang, Wei; Lu, Zheng-Tian; Mueller, Peter; Yang, Guo-Min

    2014-05-01

    The Waste Isolation Pilot Plant (WIPP) in New Mexico is the first geologic repository for disposal of transuranic nuclear waste from defense-related programs of the US Department of Energy. It is constructed within halite beds of the Permian-age Salado Formation. The Culebra Dolomite, confined within Rustler Formation evaporites overlying the Salado Formation, is a potential pathway for radionuclide transport from the repository to the accessible environment in the human-disturbed repository scenario. Although extensive subsurface characterization and numerical flow modeling of groundwater has been done in the vicinity of the WIPP, few studies have used natural isotopic tracers to validate the flow models and to better understand solute transport at this site. The advent of Atom-Trap Trace Analysis (ATTA) has enabled routine measurement of cosmogenic (81)Kr (half-life 229,000 yr), a near-ideal tracer for long-term groundwater transport. We measured (81)Kr in saline groundwater sampled from two Culebra Dolomite monitoring wells near the WIPP site, and compared (81)Kr model ages with reverse particle-tracking results of well-calibrated flow models. The (81)Kr model ages are ~130,000 and ~330,000 yr for high-transmissivity and low-transmissivity portions of the formation, respectively. Compared with flow model results which indicate a relatively young mean hydraulic age (~32,000 yr), the (81)Kr model ages imply substantial physical attenuation of conservative solutes in the Culebra Dolomite and provide limits on the effective diffusivity of contaminants into the confining aquitards. PMID:24594409

  1. A transgenic mouse line for collecting ribosome-bound mRNA using the tetracycline transactivator system

    Directory of Open Access Journals (Sweden)

    Laurel Drane

    2014-10-01

    Full Text Available Acquiring the gene expression profiles of specific neuronal cell-types is important for understanding their molecular identities. Genome-wide gene expression profiles of genetically defined cell-types can be acquired by collecting and sequencing mRNA that is bound to epitope-tagged ribosomes (TRAP; Translating Ribosome Affinity Purification. Here, we introduce a transgenic mouse model that combines the TRAP technique with the tetracycline transactivator (tTA system by expressing EGFP-tagged ribosomal protein L10a (EGFP-L10a under control of the tetracycline response element (tetO-TRAP. This allows both spatial control of EGFP-L10a expression through cell-type specific tTA expression, as well as temporal regulation by inhibiting transgene expression through the administration of doxycycline. We show that crossing tetO-TRAP mice with transgenic mice expressing tTA under the Camk2a promoter (Camk2a-tTA results in offspring with cell-type specific expression of EGFP-L10a in CA1 pyramidal neurons and medium spiny neurons in the striatum. Co-immunoprecipitation confirmed that EGFP-L10a integrates into a functional ribosomal complex. In addition, collection of ribosome-bound mRNA from the hippocampus yielded the expected enrichment of genes expressed in CA1 pyramidal neurons, as well as a depletion of genes expressed in other hippocampal cell-types. Finally, we show that crossing tetO-TRAP mice with transgenic Fos-tTA mice enables the expression of EGFP-L10a in CA1 pyramidal neurons that are activated during a fear conditioning trial. The tetO-TRAP mouse can be combined with other tTA mouse lines to enable gene expression profiling of a variety of different cell-types.

  2. Purpureocillium lilacinum, potential agent for biological control of the leaf-cutting ant Acromyrmex lundii.

    Science.gov (United States)

    Goffré, D; Folgarait, P J

    2015-09-01

    Many leaf-cutter ant species are well known pests in Latin America, including species of the genera Acromyrmex and Atta. An environmentally friendly strategy to reduce the number of leafcutter ants and avoid indiscriminate use of chemical pesticides is biological control. In this work we evaluated the effectiveness of a strain of the entomopathogen Purpureocillium lilacinum, against worker ants from six Acromyrmex lundii field colonies, after immersions in pure suspensions at a concentration of 1×10(6)conidiaml(-1). Survival of ants treated with P. lilacinum was significantly lower than that recorded in controls, and median lethal time (LT50) was 6-7days. P. lilacinum was responsible for 85.6% (80.6-89.7) of the mortality in inoculated ants, in which we found that the percentage of other entomopathogens that naturally infected ants decreased also, suggesting a good competitive capability of the fungus. Horizontal transmission to non-inoculated ants was also evidenced, given that 58.5% (41.9-64.2) of them died because of P. lilacinum. Moreover, we tested pathogenicity for three concentrations of this strain (1.0×10(4), 10(6) and 10(8)conidiaml(-1)) and found a significantly faster mortality of ants and greater median percentage of infection at 10(8)conidiaml(-1) of P. lilacinum. CL50 value was 2.8×10(5)conidiaml(-1). We thus propose the use of P. lilacinum as a biological control agent of leafcutter ants in crops and plantations. PMID:26205173

  3. Mesenchymal stem cell therapy for osteoarthritis: current perspectives

    Directory of Open Access Journals (Sweden)

    Wyles CC

    2015-08-01

    Full Text Available Cody C Wyles,1 Matthew T Houdek,2 Atta Behfar,3 Rafael J Sierra,21Mayo Medical School, 2Department of Orthopedic Surgery, 3Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, USAAbstract: Osteoarthritis (OA is a painful chronic condition with a significant impact on quality of life. The societal burden imposed by OA is increasing in parallel with the aging population; however, no therapies have demonstrated efficacy in preventing the progression of this degenerative joint disease. Current mainstays of therapy include activity modification, conservative pain management strategies, weight loss, and if necessary, replacement of the affected joint. Mesenchymal stem cells (MSCs are a multipotent endogenous population of progenitors capable of differentiation to musculoskeletal tissues. MSCs have a well-documented immunomodulatory role, managing the inflammatory response primarily through paracrine signaling. Given these properties, MSCs have been proposed as a potential regenerative cell therapy source for patients with OA. Research efforts are focused on determining the ideal source for derivation, as MSCs are native to several tissues. Furthermore, optimizing the mode of delivery remains a challenge both for appropriate localization of MSCs and for directed guidance toward stemming the local inflammatory process and initiating a regenerative response. Scaffolds and matrices with growth factor adjuvants may prove critical in this effort. The purpose of this review is to summarize the current state of MSC-based therapeutics for OA and discuss potential barriers that must be overcome for successful implementation of cell-based therapy as a routine treatment strategy in orthopedics.Keywords: mesenchymal stem cell, osteoarthritis, treatment, regenerative medicine, cell therapy

  4. In-situ studies on volatile jet exhaust particle emissions - impacts of fuel sulfur content and environmental conditions on nuclei-mode aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, F.; Baumann, R.; Petzold, A.; Busen, R.; Schulte, P.; Fiebig, M. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Wessling (Germany). Inst. fuer Physik der Atmosphaere; Brock, C.A. [Denver Univ., CO (United States). Dept. of Engineering

    2000-02-01

    In-situ measurements of ultrafine aerosol particle emissions were performed at cruise altitudes behind the DLR ATTAS research jet (RR M45H M501 engines) and a B737-300 aircraft (CFM56-3B1 engines). Measurements were made 0.15-20 seconds after emission as the source aircraft burned fuel with sulfur contents (FSC) of 2.6, 56 or 118 mg kg{sup -1}. Particle size distributions of from 3 to 60 nm diameter were determined using CN-counters with varying lower size detection limits. Volatile particle concentrations in the aircraft plumes strongly increased as diameter decreased toward the sizes of large molecular clusters, illustrating that apparent particle emissions are extremely sensitive to the smallest particle size detectable by the instrument used. Environmental conditions and plume age alone could influence the number of detected ultrafine (volatile) aerosols within an order of magnitude, as well. The observed volatile particle emissions decreased nonlinearly as FSC decreased to 60 mg kg{sup -1}, reaching minimum values of about 2 x 10{sup 17} kg{sup -1} and 2 x 10{sup 16} kg{sup -1} for particles >3 nm and >5 nm, respectively. Volatile particle emissions did not change significantly as FSCs were further reduced below 60 mg kg{sup -1}. Volatile particle emissions did not differ significantly between the two studied engine types. In contrast, soot particle emissions from the modern CFM56-3B1 engines were 4-5 times less (4 x 10{sup 14} kg{sup -1}) than from the older RR M45H M501 engines (1.8 x 10{sup 15} kg{sup -1}). Contrail processing has been identified as an efficient sink/quenching parameter for ultrafine particles and reduces the remaining interstitial aerosol by factors 2-10 depending on particle size.

  5. Transcriptome analysis and de novo annotation of the critically endangered Amur sturgeon (Acipenser schrenckii).

    Science.gov (United States)

    Zhang, X J; Jiang, H Y; Li, L M; Yuan, L H; Chen, J P

    2016-01-01

    The aim of this study was to provide comprehensive insights into the genetic background of sturgeon by transcriptome study. We performed a de novo assembly of the Amur sturgeon Acipenser schrenckii transcriptome using Illumina Hiseq 2000 sequencing. A total of 148,817 non-redundant unigenes with base length of approximately 121,698,536 bp and ranges from 201 to 26,789 bp were obtained. All the unigenes were classified into 3368 distinct categories and 145,449 singletons by homologous transcript cluster analysis. In all, 46,865 (31.49%) unigenes showed homologous matches with Nr database and 32,214 (21.65%) unigenes were matched to Nt database. In total, 24,862 unigenes were categorized into significantly enriched 52 function groups by GO analysis, and 38,436 unigenes were classified into 25 groups by KOG prediction, as well as 128 enriched KEGG pathways were identified by 45,598 unigenes (P < 0.05). Subsequently, a total of 19,860 SSRs markers were identified with the abundant di-nucleotide type (10,658; 53.67%) and the most AT/TA motif repeats (2689; 13.54%). A total of 1341 conserved lncRNAs were identified by a customized pipeline. Our study provides new sequence and function information for A. schrenckii, which will be the basis for further genetic studies on sturgeon species. The huge number of potential SSRs and putatively conserved lncRNAs isolated by the transcriptome also shed light on research in many fields, including the evolution, conservation management, and biological processes in sturgeon. PMID:27420941

  6. The Latest Progress on the Development Strategy and Planning of Hong Kong University during the Last Decade---Based on Two Texts Analysis on “Strategic Development”%十年间香港大学发展战略与规划的若干新进展--基于两次《发展策略》的文本分析

    Institute of Scientific and Technical Information of China (English)

    陈涛

    2014-01-01

    香港大学作为享誉国内外的一流大学,极为重视大学发展战略与规划工作和研究。通过对港大连续两次《发展策略》的文本分析与比较,可以发现其十年间最突出的变化和发展趋势就在于以学生为中心,这也正是其办学理念在战略规划中的集中体现。不论是港大战略规划的制定,还是其办学理念的实践,都将对我国内地重点大学建设成为世界一流大学具有重要的借鉴意义。%As a leading university renowned both domestic and international , the University of Hong Kong atta-ches great importance to the work and research of a university development strategy and planning .Based on analysis and comparison of the two successive texts of “Strategic Development” of Hong Kong University , it is found that the most prominent change and tendency during the last decade is the student -centered concept , which is also the concentration for university -running ideas from strategic planning .Both the strategic planning and the practice of university-running ideas of Hong Kong University are useful to key universities in Chinese mainland to construct the world's top universities .

  7. Deep Metamorphic Rock Series of Bayan Wula-mountain Granite-greenstone Belt and Gold MineralizationMA Runze%巴彦乌拉山深变质岩系的花岗-绿岩带与金成矿

    Institute of Scientific and Technical Information of China (English)

    胡晰; 马润则; 陈志耕; 张腊梅; 陈娟; 刘颖倩

    2015-01-01

    A large area of Archean granite - greenstone belt exposed in Bayan wula-mountain, which bedrock outcrops good. Survey area′greenstone belt is existing as the green schist facies of tectonic schist. At present, domestic and foreign atta-ches great importance to the study of granite greenstone belt, The major reason is that research on it has mineral and geological sig-nificance. However, Gold directly affecting the financial securi-ty of the country as a precious metal, which is very important for the national economy stability. Granite - greenstone belt has a close relation with gold deposit. At present, China 's most im-portant gold producing type is greenstone type gold deposit.%巴彦乌拉山出露大面积的太古代花岗-绿岩带,基岩出露良好。本区的绿岩带是以变质程度为绿片相的构造片岩形式出现的。国内外对花岗绿岩带的研究非常重视,主要是因为其研究对矿产和地质都具有重大意义。然而金为直接影响国家金融安全的贵重金属,对于国家的经济稳定有极其重要的作用。其中花岗-绿岩带与金成矿有着密切关系。目前我国主要的产金类型为绿岩型金矿。

  8. Development of expressed sequence tag resources for Vanda Mimi Palmer and data mining for EST-SSR.

    Science.gov (United States)

    Teh, Seow-Ling; Chan, Wai-Sun; Abdullah, Janna Ong; Namasivayam, Parameswari

    2011-08-01

    Vanda Mimi Palmer (VMP) is a highly sought as fragrant-orchid hybrid in Malaysia. It is economically important in cosmetic and beauty industries and also a famous potted ornamental plant. To date, no work on fragrance-related genes of vandaceous orchids has been reported from other research groups although the analysis of floral fragrance or volatiles have been extensively studied. An expressed sequence tag (EST) resource was developed for VMP principally to mine any potential fragrance-related expressed sequence tag-simple sequence repeat (EST-SSR) for future development as markers in the identification of fragrant vandaceous orchids endemic to Malaysia. Clustering, annotation and assembling of the ESTs identified 1,196 unigenes which defined 966 singletons and 230 contigs. The VMP dbEST was functionally classified by gene ontology (GO) into three groups: molecular functions (51.2%), cellular components (16.4%) and biological processes (24.6%) while the remaining 7.8% showed no hits with GO identifier. A total of 112 EST-SSR (9.4%) was mined on which at least five units of di-, tri-, tetra-, penta-, or hexa-nucleotide repeats were predicted. The di-nucleotide motif repeats appeared to be the most frequent repeats among the detected SSRs with the AT/TA types as the most abundant among the dimerics, while AAG/TTC, AGA/TCT-type were the most frequent trimerics. The mined EST-SSR is believed to be useful in the development of EST-SSR markers that is applicable in the screening and characterization of fragrance-related transcripts in closely related species. PMID:21116862

  9. Effects of dating errors on nonparametric trend analyses of speleothem time series

    Directory of Open Access Journals (Sweden)

    M. Mudelsee

    2012-10-01

    Full Text Available A fundamental problem in paleoclimatology is to take fully into account the various error sources when examining proxy records with quantitative methods of statistical time series analysis. Records from dated climate archives such as speleothems add extra uncertainty from the age determination to the other sources that consist in measurement and proxy errors. This paper examines three stalagmite time series of oxygen isotopic composition (δ18O from two caves in western Germany, the series AH-1 from the Atta Cave and the series Bu1 and Bu4 from the Bunker Cave. These records carry regional information about past changes in winter precipitation and temperature. U/Th and radiocarbon dating reveals that they cover the later part of the Holocene, the past 8.6 thousand years (ka. We analyse centennial- to millennial-scale climate trends by means of nonparametric Gasser–Müller kernel regression. Error bands around fitted trend curves are determined by combining (1 block bootstrap resampling to preserve noise properties (shape, autocorrelation of the δ18O residuals and (2 timescale simulations (models StalAge and iscam. The timescale error influences on centennial- to millennial-scale trend estimation are not excessively large. We find a "mid-Holocene climate double-swing", from warm to cold to warm winter conditions (6.5 ka to 6.0 ka to 5.1 ka, with warm–cold amplitudes of around 0.5‰ δ18O; this finding is documented by all three records with high confidence. We also quantify the Medieval Warm Period (MWP, the Little Ice Age (LIA and the current warmth. Our analyses cannot unequivocally support the conclusion that current regional winter climate is warmer than that during the MWP.

  10. The prominent role of fungi and fungal enzymes in the ant-fungus biomass conversion symbiosis.

    Science.gov (United States)

    Lange, L; Grell, M N

    2014-06-01

    Molecular studies have added significantly to understanding of the role of fungi and fungal enzymes in the efficient biomass conversion, which takes place in the fungus garden of leaf-cutting ants. It is now clear that the fungal symbiont expresses the full spectrum of genes for degrading cellulose and other plant cell wall polysaccharides. Since the start of the genomics era, numerous interesting studies have especially focused on evolutionary, molecular, and organismal aspects of the biological and biochemical functions of the symbiosis between leaf-cutting ants (Atta spp. and Acromyrmex spp.) and their fungal symbiont Leucoagaricus gongylophorus. Macroscopic observations of the fungus-farming ant colony inherently depict the ants as the leading part of the symbiosis (the myrmicocentric approach, overshadowing the mycocentric aspects). However, at the molecular level, it is fungal enzymes that enable the ants to access the nutrition embedded in recalcitrant plant biomass. Our hypothesis is that the evolutionary events that established fungus-farming practice were predisposed by a fascinating fungal evolution toward increasing attractiveness to ants. This resulted in the ants allowing the fungus to grow in the nests and began to supply plant materials for more fungal growth. Molecular studies also confirm that specialized fungal structures, the gongylidia, with high levels of proteins and rich blend of enzymes, are essential for symbiosis. Harvested and used as ant feed, the gongylidia are the key factor for sustaining the highly complex leaf-cutting ant colony. This microbial upgrade of fresh leaves to protein-enriched animal feed can serve as inspiration for modern biorefinery technology. PMID:24728757

  11. Water and environment news. No. 26, February 2010

    International Nuclear Information System (INIS)

    In the 2010-2011 biennium, one major focal area for the Isotope Hydrology Section will be groundwater assessment - particularly regional and/or transboundary aquifers. These are geographically large aquifers, and assessments using physical hydrology are fraught with complexities and uncertainties. As these aquifers generally contain fossil water which is tens to hundreds of thousands of years old, isotopic age determination provides a cost and time effective means of aquifer assessment and modeling. Recent developments in sampling and measuring Kr-81 from researchers at the Argonne National Laboratory and University of Illinois, Chicago have made it possible to more easily use isotopes of krypton - a dissolved gas in groundwater - for dating groundwater up to about a million years old. In particular, these developments include a new technique called Atom Trap Trace Analysis (ATTA) for measuring small concentration of Kr-81 using about 50-100 litres of water sample, rather than the thousands of litres required before. Kr-81 ages allow us to go beyond the age range of about 40 000 years previously possible using carbon-14, and help build better groundwater models. This approach was recently implemented in the Nubian aquifer in northern Africa. Aquifer systems targeted for 2010 include parts of the Nubian aquifer in Libya, the Guarani in Latin America, and possibly the Northwestern Sahara and Mekong aquifers. In 50 years, the global network of isotopes in precipitation (GNIP) has gathered around 120 000 monthly isotope records from more than 900 meteorological stations. This and related work using stable isotopes is becoming much easier with laser spectroscopy machines, which mark the dawn of a new era in stable isotope hyrology. The IAEA has assisted more than 20 developing countries in acquiring a machine, and trained over 40 technicians in its use

  12. Comportamento espectral de materiais de solos e de estruturas biogênicas associadas

    Directory of Open Access Journals (Sweden)

    J. A. M. Demattê

    1998-12-01

    Full Text Available No presente estudo, verificou-se a interferência da macrofauna edáfica sobre os atributos físicos e químicos e sua relação com a reflectância espectral de um Latossolo Vermelho-Amarelo (LV, Terra Roxa Estruturada latossólica (TR e Vertissolo (V. Esses solos localizam-se em três pontos ao longo de uma toposseqüência da região de Piracicaba (SP. As amostras foram direcionadas para os agregados formados pelas formigas cortadeiras (Atta sp., cupins (Cornitermes cumulans e minhocas (Pontoscolex corethrurus, os quais foram comparados com o solo-controle sem atividade visível e recente dos animais (testemunha. Foram avaliadas a granulometria e a composição química das amostras de solo. O comportamento espectral do solo foi obtido em laboratório, utilizando espectroradiômetro entre 400 e 2.500 nm. Os coprólitos de minhoca apresentaram 2 a 3 vezes mais fósforo e um incremento de 30 a 50% na matéria orgânica em relação ao horizonte superficial do solo. Os agregados de cupins e formigas apresentaram composição química semelhante à dos horizontes subsuperficiais dos solos. O comportamento espectral dos agregados biológicos variou conforme sua composição química e profundidade de ação dos animais. No caso da minhoca, as curvas de reflectância foram semelhantes às do horizonte superficial para os três solos. Para as estruturas de cupim e formiga, tanto a composição química como o comportamento espectral corresponderam ao horizonte subsuperficial no LV e TR.

  13. Pharmacoinformatics approach for investigation of alternative potential hepatitis C virus nonstructural protein 5B inhibitors

    Directory of Open Access Journals (Sweden)

    Mirza MU

    2015-03-01

    Full Text Available Muhammad Usman Mirza,1 Noor-Ul-Huda Ghori,2 Nazia Ikram,3 Abdur Rehman Adil,4 Sadia Manzoor3 1Centre for Research in Molecular Medicine (CRiMM, The University of Lahore, Lahore, 2Atta-ur-Rehman School of Applied Biosciences (ASAB, National University of Science and Technology, Islamabad, 3Institute of Molecular Biology and Biotechnology (IMBB, The University of Lahore, Lahore, Pakistan; 4Centre for Excellence in Molecular Biology (CEMB, The University of Punjab, Lahore, Pakistan Abstract: Hepatitis C virus (HCV is one of the major viruses affecting the world today. It is a highly variable virus, having a rapid reproduction and evolution rate. The variability of genomes is due to hasty replication catalyzed by nonstructural protein 5B (NS5B which is also a potential target site for the development of anti-HCV agents. Recently, the US Food and Drug Administration approved sofosbuvir as a novel oral NS5B inhibitor for the treatment of HCV. Unfortunately, it is much highlighted for its pricing issues. Hence, there is an urgent need to scrutinize alternate therapies against HCV that are available at affordable price and do not have associated side effects. Such a need is crucial especially in underdeveloped countries. The search for various new bioactive compounds from plants is a key part of pharmaceutical research. In the current study, we applied a pharmacoinformatics-based approach for the identification of active plant-derived compounds against NS5B. The results were compared to docking results of sofosbuvir. The lead compounds with high-binding ligands were further analyzed for pharmacokinetic and pharmacodynamic parameters based on in silico absorption, distribution, metabolism, excretion, and toxicity (ADMET profile. The results showed the potential alternative lead compounds that can be developed into commercial drugs having high binding energy and promising ADMET properties. Keywords: hepatitis C, NS5B inhibitors, molecular docking, Auto

  14. 电阻抗监护小猪腹膜后注血模型的研究%Experimental study on electrical impedance tomography for monitoring retroperitoneal inject blood model in pigs

    Institute of Scientific and Technical Information of China (English)

    张鸿毅; 张伟; 保庭毅; 高玉杰; 尤富生; 帅万钧; 付峰; 董秀珍

    2009-01-01

    目的 使用小猪腹膜后注血模型来研究电阻抗成像监测创伤导致的腹膜后出血的可行性,为电阻抗成像的临床应用提供必要的理论和现实依据.方法 5头小猪行腹膜后穿刺置管,经导管持续注入血液,模拟创伤性腹膜后出血,应用电阻抗成像临测小猪注血部位的阻抗和图像变化情况.结果 5头腹膜后注血小猪电阻抗监护图像成像清晰,稳定.注血部位的阻抗值随注血量的增加而持续降低,图像灰度变化明显.经CT及解剖验证,后腹膜完整,血液局限于腹膜后间隙内.结论 在小猪腹膜后注血模型的基础上,使用电阻抗监护腹膜后出血成像清晰,对比明显.%Objective To apply electrical impedance tnmography that is a new evaluation ap-proach to monitor the development of retroperitoneal injury. We used retroperitoneal inject blood model in pigs to study the feasibility on monitoring retroperitoneal bleeding and to provide premise in theory and practice for clinical application. Methods Five pigs were used on the experiment. We insert a vessel into the retroperitoneal and inject blood to simulate retroperitoneal bleeding. Sixteen electrodes were atta-ched on the abdominal region circumference of pigs and used for electrical current injection and surface voltage measurement. Then the monitoring images were performed by electrical impedance tomography. Results The images of electrical impedance tomography retroperitoneal inject blood model of five pigs were clear, the minimal impedance scale was decreasing significantly as the bleeding volume increasing and the images were changed significantly too. The computerized tomography and the dissecting results confirmed the blood was limited in retroperitoneal. Conclusions The establishments of pigs retroper-itoneal inject blood model was successful. The images of electrical impedance tomography retroperitoneal inject blood model were clear with significant contrast. It's feasible to use

  15. Quality in hospitals environment; La qualita' nell'ambiente ospedaliero. Studio di prevalenza sull'abitudine al fumo di tabacco tra gli operatori di un ospedale cittadino

    Energy Technology Data Exchange (ETDEWEB)

    Callegaro, G.; Saia, M.; Mariotto, A. [Unita' Sanitaria Locale 16, Padua (Italy). Direzione sanitaria; Buttarello, M. [Ospedale Geriatrico, Padua (Italy). Laboratorio di Patologia Clinica

    2000-10-01

    sottoposto era composto da persone che avevamo fumato negli ultimi sei mesi, il 29% era composto da non fumatori, mentre il 30.5% da ex-fumatori. Nei confronti del fumo passivo e delle problematiche fumo-indotte emerge la necessita' di proporre una valida strategia atta a sensibilizzare anche il personale ospedaliero.

  16. Solubility enhancement of simvastatin by arginine: thermodynamics, solute–solvent interactions, and spectral analysis

    Directory of Open Access Journals (Sweden)

    Meor Mohd Affandi MMR

    2016-03-01

    Full Text Available MMR Meor Mohd Affandi,1,2 Minaketan Tripathy,1,3 Syed Adnan Ali Shah,3,4 ABA Majeed1,3 1Laboratory of Fundamental Pharmaceutics, Faculty of Pharmacy, Universiti Teknologi MARA (UiTM, Bandar Puncak Alam, Selangor, Malaysia; 2DDH Core, Universiti Teknologi MARA (UiTM, Shah Alam, Selangor Darul Ehsan, Malaysia; 3Pharmaceutical and Life Sciences Core, Universiti Teknologi MARA (UiTM, Shah Alam, Selangor Darul Ehsan, Malaysia; 4Atta-ur-Rahman Institute for Natural Products Discovery (AuRIns, Faculty of Pharmacy, Universiti Teknologi MARA (UiTM, Bandar Puncak Alam, Selangor, Malaysia Abstract: We examined the solubility of simvastatin in water in 0.01 mol·dm-3, 0.02 mol·dm-3, 0.04 mol·dm-3, 0.09 mol·dm-3, 0.18 mol·dm-3, 0.36 mol·dm-3, and 0.73 mol·dm-3 arginine (ARG solutions. The investigated drug is termed the solute, whereas ARG the cosolute. Phase solubility studies illustrated a higher extent of solubility enhancement for simvastatin. The aforementioned system was subjected to conductometric and volumetric measurements at temperatures (T of 298.15 K, 303.15 K, 308.15 K, and 313.15 K to illustrate the thermodynamics involved and related solute–solvent interactions. The conductance values were used to evaluate the limiting molar conductance and association constants. Thermodynamic parameters (ΔG0, ΔH0, ΔS0, and Es for the association process of the solute in the aqueous solutions of ARG were calculated. Limiting partial molar volumes and expansibilities were evaluated from the density values. These values are discussed in terms of the solute–solvent and solute–cosolute interactions. Further, these systems were analyzed using ultraviolet–visible analysis, Fourier-transform infrared spectroscopy, and 13C, 1H, and two-dimensional nuclear overhauser effect spectroscopy nuclear magnetic resonance to complement thermophysical explanation. Keywords: simvastatin–arginine complex, solubility, volumetric, conductometric

  17. Measurements of Nucleation-Mode Particle Size Distributions in Aircraft Plumes during SULFUR 6

    Science.gov (United States)

    Brock, Charles A.; Bradford, Deborah G.

    1999-01-01

    This report summarizes the participation of the University of Denver in an airborne measurement program, SULFUR 6, which was undertaken in late September and early October of 1998 by the Deutsches Zentrum fur Luft und Raumfahrt (DLR). Scientific findings from two papers that have been published or accepted and from one manuscript that is in preparation are presented. The SULFUR 6 experiment was designed to investigate the emissions from subsonic aircraft to constrain calculations of possible atmospheric chemical and climatic effects. The University of Denver effort contributed toward the following SULFUR 6 goals: (1) To investigate the relationship between fuel sulfur content (FSC--mass of sulfur per mass of fuel) and particle number and mass emission index (El--quantity emitted per kg of fuel burned); (2) To provide upper and lower limits for the mass conversion efficiency (nu) of fuel sulfur to gaseous and particulate sulfuric acid; (3) To constrain models of volatile particle nucleation and growth by measuring the particle size distribution between 3 and 100 nm at aircraft plume ages ranging from 10(exp -1) to 10(exp 3) s; (4) To determine microphysical and optical properties and bulk chemical composition of soot particles in aircraft exhaust; and (5) To investigate the differences in particle properties between aircraft plumes in contrail and non-contrail situations. The experiment focused on emissions from the ATTAS research aircraft (a well characterized, but older technology turbojet) and from an in-service Boeing 737-300 aircraft provided by Lufthansa, with modem, high-bypass turbofan engines. Measurements were made from the DLR Dassault Falcon 900 aircraft, a modified business jet. The Atmospheric Effects of Aviation Program (AEAP) provided funding to operate an instrument, the nucleation-mode aerosol size spectrometer (N-MASS), during the SULFUR 6 campaign and to analyze the data. The N-MASS was developed at the University of Denver with the support of

  18. Effects of IL-10 haplotype and atomic bomb radiation exposure on gastric cancer risk.

    Science.gov (United States)

    Hayashi, Tomonori; Ito, Reiko; Cologne, John; Maki, Mayumi; Morishita, Yukari; Nagamura, Hiroko; Sasaki, Keiko; Hayashi, Ikue; Imai, Kazue; Yoshida, Kengo; Kajimura, Junko; Kyoizumi, Seishi; Kusunoki, Yoichiro; Ohishi, Waka; Fujiwara, Saeko; Akahoshi, Masazumi; Nakachi, Kei

    2013-07-01

    Gastric cancer (GC) is one of the cancers that reveal increased risk of mortality and incidence in atomic bomb survivors. The incidence of gastric cancer in the Life Span Study cohort of the Radiation Effects Research Foundation (RERF) increased with radiation dose (gender-averaged excess relative risk per Gy = 0.28) and remains high more than 65 years after exposure. To assess a possible role of gene-environment interaction, we examined the dose response for gastric cancer incidence based on immunosuppression-related IL-10 genotype, in a cohort study with 200 cancer cases (93 intestinal, 96 diffuse and 11 other types) among 4,690 atomic bomb survivors participating in an immunological substudy. Using a single haplotype block composed of four haplotype-tagging SNPs (comprising the major haplotype allele IL-10-ATTA and the minor haplotype allele IL-10-GGCG, which are categorized by IL-10 polymorphisms at -819A>G and -592T>G, +1177T>C and +1589A>G), multiplicative and additive models for joint effects of radiation and this IL-10 haplotyping were examined. The IL-10 minor haplotype allele(s) was a risk factor for intestinal type gastric cancer but not for diffuse type gastric cancer. Radiation was not associated with intestinal type gastric cancer. In diffuse type gastric cancer, the haplotype-specific excess relative risk (ERR) for radiation was statistically significant only in the major homozygote category of IL-10 (ERR = 0.46/Gy, P = 0.037), whereas estimated ERR for radiation with the minor IL-10 homozygotes was close to 0 and nonsignificant. Thus, the minor IL-10 haplotype might act to reduce the radiation related risk of diffuse-type gastric cancer. The results suggest that this IL-10 haplotyping might be involved in development of radiation-associated gastric cancer of the diffuse type, and that IL-10 haplotypes may explain individual differences in the radiation-related risk of gastric cancer. PMID:23772925

  19. Relationship between Workplace Incivility, Job Attitudes and Muslim Religiosity Personality among Trade Union Members

    Directory of Open Access Journals (Sweden)

    Azizan H. M.

    2016-12-01

    Full Text Available In reality, workplace incivility has its fair share of attention in organizational research dealing with its causes and effect relationships. In Islam, incivility equates the negative character (akhlak of ridiculing others. Consequently, the purpose of this study is to investigate relationship between the experience of workplace incivility and job attitudes as well as the moderating effect of Muslim religiosity personality, which is measured by Muslim Religiosity-Personality Inventory (MRPI, on the relationships. In other words, this study plans to analyze whether Muslim employees, who possess religiosity personality would be able to endure workplace incivility experiences. Basically, literature by Al-Ghazali, Al-Attas and Al-Raiya on Islamic personality serve as the main foundation of the study. In addition, the works of Baron and Neuman (1998, Andersson & Pearson (1999 and Schilpzand, et. al (2014 were reviewed and a research framework was developed. The quantitative survey consisted of five sections used to measure the experience of workplace incivility, job attitudes, religiosity personality and demographics. A sample of 163 Malaysian Muslim bank workers completed the survey. Four main variables have been analyzed and their descriptive analyses are as the following. Scores for Workplace Incivility variable (M=3.34, SD=.27; Job Satisfaction variable (M=1.79, SD=.65; Organizational Commitment variable (M=2.74, SD=.34 and Muslim Religiosity Personality (M=3.60, SD=.42. As for the Pearson’s Correlation test, the result indicates that Workplace Incivility variable has inverse correlations with both job attitude variables (Job Satisfaction, R=-.611, p=.01; Organizational Commitment, R=.731,p=.01. Meanwhile, the overall model was significant, R2 = .401, F(3, 159 = 24.06, p= .01. Tests to see if the data met the assumption of collinearity indicate that multicollinearity was not a concern (Job Satisfaction, Tolerance = .96, VIF = 1

  20. Citotossicity in immune system's cells exposed in vitro to a microwave electromagnetic field in two different exposure systems operating at mobile telephones frequencies; Citotossicita' in cellule del sistema immunitario esposte in vitro al campo elettromagnetico a microonde in due diversi sistemi espositivi operanti alle frequenze della telefonia mobile

    Energy Technology Data Exchange (ETDEWEB)

    Scarcella, E.; Ardoino, L.; Galloni, P.; Mancini, S.; Marino, C. [ENEA, Divisione Protezione dell' Uomo e degli Ecosistemi, Centro Ricerche Casaccia, Rome (Italy)

    2001-07-01

    funzionamento di cellule macrofagiche stabilizzate e coltivate in vitro (RAW 264.7) responsabili dei meccanismi di difesa specifica e aspecifica del sistema immunitario. Sono stati, inoltre, standardizzati due diversi sistemi espositivi operanti a 900 MHz a differenti livelli di densita' di potenza (da 1 a 100 W/m{sup 2}) per garantire condizioni elettromagnetiche omogenee, idonee condizioni di incubazione delle cellule e la riproducibilita' degli esperimenti. Il lavoro di standardizzazione dei sistemi espositivi e i risultati sperimentali di questa ricerca, che hanno evidenziato differenze significative della crescita e della funzionalita' macrofagica solo al livello di densita' di potenza piu' elevato (100 W/m{sup 2}), ma recuperare dopo 48 ore dall'esposizione, risultano essere preliminari e propedeutici per una programmazione sperimentale futura atta ad approfondire una valutazione bio-tossicologica in vitro.

  1. Metodología para la evaluación del potencial insecticida de especies forestales.

    Directory of Open Access Journals (Sweden)

    Morales Soto León

    2000-06-01

    Full Text Available La diversidad florística de Colombia plantea enormes retos de investigación, con miras a una utilización racional e integral de sus recursos forestales. Las plantas con efectos biocidas utilizables en el control de plagas o enfermedades revisten una singular importancia. El objetivo de este trabajo es plantear una metodología de fácil aplicación, bajo costo y rápidos resultados, que permita acopiar la información necesaria sobre el mayor número de especies con potencial en este sentido. La metodología plantea la siguiente secuencia: selección de las especies vegetales de interés, apoyada en los reportes bibliográficos, conocimiento ancestral y observaciones personales; recolección del material en el campo; preparación del extracto total a partir del material seco; pruebas iniciales con Artemia salina Lech. para detectar actividad biológica, a través de la determinación de la LC50 (las especies con LC50 menores de 1000 ppm se consideran promisorias y ameritan procesos posteriores de fraccionamiento químico, bioensayos con las sustancias más promisorias sobre algún organismo de interés particular y determinación final de los compuestos activos en la planta. La metodología descrita fue empleada en la evaluación del potencial de acción biocida de 5 especies arbóreas o arbustivas, Guarea guidonia (L. Sleumer y Trichia hirta L. (Meliaceae, Machaerium moritzianum Benth. (Fabaceae, Swinglea glutinosa Merrill. (Rutaceae y Mammea americana L. (Clusiaceae. Se utilizó para los bioensayos iniciales el microcrustáceo Artemia salina Leach como indicador del potencial biocida con el fin de seleccionar las dos especies más promisorias a partir de las LC50 obtenidas. Con las dos se realizaron los bioensayos para evaluar la acción fagoinhibidora en la hormiga arriera Atta cephalotes (L., y el posible control de Alconeura sp. (Homoptera: Cicadellidae, insecto chupador que afecta la ceiba verde Pseudobombax septenatum (Jacq. Dugand

  2. The evolution of genome size in ants

    Directory of Open Access Journals (Sweden)

    Spagna Joseph C

    2008-02-01

    Full Text Available Abstract Background Despite the economic and ecological importance of ants, genomic tools for this family (Formicidae remain woefully scarce. Knowledge of genome size, for example, is a useful and necessary prerequisite for the development of many genomic resources, yet it has been reported for only one ant species (Solenopsis invicta, and the two published estimates for this species differ by 146.7 Mb (0.15 pg. Results Here, we report the genome size for 40 species of ants distributed across 10 of the 20 currently recognized subfamilies, thus making Formicidae the 4th most surveyed insect family and elevating the Hymenoptera to the 5th most surveyed insect order. Our analysis spans much of the ant phylogeny, from the less derived Amblyoponinae and Ponerinae to the more derived Myrmicinae, Formicinae and Dolichoderinae. We include a number of interesting and important taxa, including the invasive Argentine ant (Linepithema humile, Neotropical army ants (genera Eciton and Labidus, trapjaw ants (Odontomachus, fungus-growing ants (Apterostigma, Atta and Sericomyrmex, harvester ants (Messor, Pheidole and Pogonomyrmex, carpenter ants (Camponotus, a fire ant (Solenopsis, and a bulldog ant (Myrmecia. Our results show that ants possess small genomes relative to most other insects, yet genome size varies three-fold across this insect family. Moreover, our data suggest that two whole-genome duplications may have occurred in the ancestors of the modern Ectatomma and Apterostigma. Although some previous studies of other taxa have revealed a relationship between genome size and body size, our phylogenetically-controlled analysis of this correlation did not reveal a significant relationship. Conclusion This is the first analysis of genome size in ants (Formicidae and the first across multiple species of social insects. We show that genome size is a variable trait that can evolve gradually over long time spans, as well as rapidly, through processes that may

  3. Glycyrrhetinic acid and E.resveratroloside act as potential plant derived compounds against dopamine receptor D3 for Parkinson’s disease: a pharmacoinformatics study

    Directory of Open Access Journals (Sweden)

    Mirza MU

    2014-12-01

    Full Text Available Muhammad Usman Mirza,1 A Hammad Mirza,2 Noor-Ul-Huda Ghori,3 Saba Ferdous4 1Centre for Research in Molecular Medicine, The University of Lahore, Lahore, Pakistan; 2Department of Bioscience, COMSATS Institute of Information Technology, Sahiwal, Pakistan; 3Atta-ur-Rehman School of Applied Biosciences, National University of Science and Technology, Islamabad, Pakistan; 4Institute of Structural and Molecular Biology, University College London, UK Abstract: Parkinson’s disease (PD is caused by loss in nigrostriatal dopaminergic neurons and is ranked as the second most common neurodegenerative disorder. Dopamine receptor D3 is considered as a potential target in drug development against PD because of its lesser side effects and higher degree of neuro-protection. One of the prominent therapies currently available for PD is the use of dopamine agonists which mimic the natural action of dopamine in the brain and stimulate dopamine receptors directly. Unfortunately, use of these pharmacological therapies such as bromocriptine, apomorphine, and ropinirole provides only temporary relief of the disease symptoms and is frequently linked with insomnia, anxiety, depression, and agitation. Thus, there is a need for an alternative treatment that not only hinders neurodegeneration, but also has few or no side effects. Since the past decade, much attention has been given to exploitation of phytochemicals and their use in alternative medicine research. This is because plants are a cheap, indispensable, and never ending resource of active compounds that are beneficial against various diseases. In the current study, 40 active phytochemicals against PD were selected through literature survey. These ligands were docked with dopamine receptor D3 using AutoDock and AutoDockVina. Binding energies were compared to docking results of drugs approved by the US Food and Drug Administration against PD. The compounds were further analyzed for their absorption, distribution

  4. Kidney function and mortality post-liver transplant in the Model for End-Stage Liver Disease era

    Directory of Open Access Journals (Sweden)

    Sethi A

    2011-11-01

    Full Text Available Aastha Sethi1, Michelle M Estrella1, Richard Ugarte2, Mohamed G Atta1 1Johns Hopkins University School of Medicine, Department of Medicine, Baltimore, MD, USA; 2University of Maryland Medical Center, Department of Medicine, Baltimore, MD, USA Abstract: The Model for End-Stage Liver Disease (MELD score incorporates serum creatinine and was introduced to facilitate allocation of orthotopic liver transplantation (LT. The objective is to determine the impact of MELD and kidney function on all-cause mortality. Among LTs performed in a tertiary referral hospital between 1995 and 2009, 419 cases were studied. Cox proportional hazards models were constructed to estimate the hazard ratios (HR and 95% confidence intervals (CI for death. Over mean follow-ups of 8.4 and 3.1 years during the pre-MELD and MELD era, 57 and 63 deaths were observed, respectively. Those transplanted during the MELD era had a higher likelihood of hepatorenal syndrome (8% vs 2%, P < 0.01, lower kidney function (median estimated glomerular filtration rate [eGFR] 77.8 vs 92.6 mL/min/1.73 m2, P < 0.01, and more pretransplantation renal replacement therapy (RRT (5% vs 1%; P < 0.01. All-cause mortality risk was similar in the MELD vs the pre-MELD era (HR: 0.98, 95% CI: 0.58–1.65. The risk of death, however, was nearly 3-fold greater (95% CI: 1.14–6.60 among those requiring pre-transplant RRT. Similarly, eGFR < 60 mL/min/1.73 m2 post-transplant was associated with a 2.5-fold higher mortality (95% CI: 1.48–4.11. The study suggests that MELD implementation had no impact on all-cause mortality post-LT. However, the need for pre-transplant RRT and post-transplant kidney dysfunction was associated with a more than 2-fold greater risk of subsequent death. Keywords: eGFR, mortality, MELD, liver transplant

  5. How can AN Approach to Steam BE Authentic to both Science and Art?

    Science.gov (United States)

    LaFayette, C. J.; Parke, Ph D., F. I.; Pierce, C.; Nakamura, T.

    2015-12-01

    A collaborative project engaged a team of geophysicists, engineers, entomologists, and artists to visualize tunnels and chambers of a vast, leafcutting ant colony in rural Texas. Part of the plan was to test the nature of significant outcomes in different domains and contexts. Our team used Ground Penetrating Radar to scan part of the nest, then translate the data into 3D geometry to be experienced on an immersive visualization system. This provided the ability to zoom out of and into the model. The tunnel fragment could appear like a tiny crumb floating in air, or one could move inside it to view details and tunnel architecture. Exterior and interior structure could thus be perceived in a seamless way. The system enabled a kinesthetic sense — one both saw and felt surrounded by the scene. This was the first time GPR had been used to map a living ant colony. Due to this project, entomologists have begun to use GPR with encouraging results. The Atta project inspired in us an enjoyment of experimentation and collaboration. Results were exhibited in international art venues, published in scientific journals, and demonstrated at hybrid venues for art and science. Each form of dissemination was suited to the host. Whether the result can be called art, science, or a blend is determined by its reception in a larger community. Like the species name and the pathway worn from tree to nest, the process of mapping the colony took the form of a palindrome: we pulled something out of the ground, passed it back and forth, and hoisted it out into the world. The role of art in collaboration with science can take many forms. Art can enhance science understanding for non-scientists. Artists and scientists can co-invent new tools for inquiry. Artists are adept at creating ways to experience and understand data or phenomena through multi-modal experiences, for example, aural, haptic, or olfactory. Artists are trained to foreground the process of making as part of the "performance

  6. An overview of the Phalaenopsis orchid genome through BAC end sequence analysis

    Directory of Open Access Journals (Sweden)

    Hsiao Yu-Yun

    2011-01-01

    Full Text Available Abstract Background Phalaenopsis orchids are popular floral crops, and development of new cultivars is economically important to floricultural industries worldwide. Analysis of orchid genes could facilitate orchid improvement. Bacterial artificial chromosome (BAC end sequences (BESs can provide the first glimpses into the sequence composition of a novel genome and can yield molecular markers for use in genetic mapping and breeding. Results We used two BAC libraries (constructed using the BamHI and HindIII restriction enzymes of Phalaenopsis equestris to generate pair-end sequences from 2,920 BAC clones (71.4% and 28.6% from the BamHI and HindIII libraries, respectively, at a success rate of 95.7%. A total of 5,535 BESs were generated, representing 4.5 Mb, or about 0.3% of the Phalaenopsis genome. The trimmed sequences ranged from 123 to 1,397 base pairs (bp in size, with an average edited read length of 821 bp. When these BESs were subjected to sequence homology searches, it was found that 641 (11.6% were predicted to represent protein-encoding regions, whereas 1,272 (23.0% contained repetitive DNA. Most of the repetitive DNA sequences were gypsy- and copia-like retrotransposons (41.9% and 12.8%, respectively, whereas only 10.8% were DNA transposons. Further, 950 potential simple sequence repeats (SSRs were discovered. Dinucleotides were the most abundant repeat motifs; AT/TA dimer repeats were the most frequent SSRs, representing 253 (26.6% of all identified SSRs. Microsynteny analysis revealed that more BESs mapped to the whole-genome sequences of poplar than to those of grape or Arabidopsis, and even fewer mapped to the rice genome. This work will facilitate analysis of the Phalaenopsis genome, and will help clarify similarities and differences in genome composition between orchids and other plant species. Conclusion Using BES analysis, we obtained an overview of the Phalaenopsis genome in terms of gene abundance, the presence of repetitive

  7. Does the long-range transport of African mineral dust across the Atlantic enhance their hygroscopicity?

    Science.gov (United States)

    Denjean, Cyrielle; Caquineau, Sandrine; Desboeufs, Karine; Laurent, Benoit; Quiñones Rosado, Mariana; Vallejo, Pamela; Mayol-Bracero, Olga; Formenti, Paola

    2015-04-01

    Influence of mineral dust on radiation balance is largely dependent on their ability to interact with water. While fresh mineral dusts are highly hydrophobic, various transformation processes (coagulation, heterogeneous chemical reaction) can modify the dust physical and chemical properties during long-range transport, which, in turn, can change the dust hygroscopic properties. The model predictions of the radiative effect by mineral dust still suffer of the lack of certainty of dust hygroscopic properties, and their temporal evolution during long-range transport. We present the first direct surface measurements of the hygroscopicity of Saharan dust after long-range transport over the Atlantic Ocean, their relationship with chemical composition, their influence on particle size and shape and implications for optical properties. Particles were collected during the DUST Aging and TransporT from Africa to the Caribbean (Dust-AttaCk) campaign at the Cape San Juan Puerto Rico station in June-July 2012. Environmental scanning electron microscopy (ESEM) was used to analyze the size, shape, chemical composition and hygroscopic properties of individual particles. At different levels of concentrations in summertime, the coarse mode of atmospheric aerosols in Puerto Rico is dominated by Saharan mineral dust. Most of aged dust particles survived atmospheric transport intact with no observed internal mixture with other species and did not show hygroscopic growth up to 94% relative humidity. This is certainly due to the fact that in summertime dust is mostly transported above the marine boundary layer. A minor portion of mineral dust (approximately 19-28% by number) were involved in atmospheric heterogeneous reactions with acidic gases (likely SO2 and HCl) and sea salt aggregation. While sulfate- and chloride-coated dust remained extremely hydrophobic, dust particles in internal mixing with NaCl underwent profound changes in their hygroscopicity, therefore in size and shape. We

  8. Cytogenetic data on six leafcutter ants of the genus Acromyrmex Mayr, 1865 (Hymenoptera, Formicidae, Myrmicinae): insights into chromosome evolution and taxonomic implications

    Science.gov (United States)

    Barros, Luísa Antônia Campos; de Aguiar, Hilton Jeferson Alves Cardoso; Mariano, Cléa dos Santos Ferreira; Andrade-Souza, Vanderly; Costa, Marco Antonio; Delabie, Jacques Hubert Charles; Pompolo, Silvia das Graças

    2016-01-01

    Abstract Cytogenetic data for the genus Acromyrmex Mayr, 1865 are available, to date, for a few species from Brazil and Uruguay, which have uniform chromosome numbers (2n = 38). The recent cytogenetic data of Acromyrmex striatus (Roger, 1863), including its banding patterns, showed a distinct karyotype (2n = 22), similar to earlier studied Atta Fabricius, 1804 species. Karyological data are still scarce for the leafcutter ants and many gaps are still present for a proper understanding of this group. Therefore, this study aimed at increasing cytogenetic knowledge of the genus through the characterization of other six species: Acromyrmex balzani (Emery, 1890), Acromyrmex coronatus Fabricius, 1804, Acromyrmex disciger (Mayr, 1887), Acromyrmex echinatior (Forel, 1899), Acromyrmex niger (Smith, 1858) and Acromyrmex rugosus (Smith, 1858), all of which were collected in Minas Gerais – Brazil, except for Acromyrmex echinatior which was collected in Barro Colorado – Panama. The number and morphology of the chromosomes were studied and the following banding techniques were applied: C-banding, fluorochromes CMA3 and DAPI, as well as the detection of 45S rDNA using FISH technique. All the six species had the same chromosome number observed for already studied species, i.e. 2n = 38. Acromyrmex balzani had a different karyotype compared with other species mainly due to the first metacentric pair. The heterochromatin distribution also showed interspecific variation. Nevertheless, all the studied species had a pair of bands in the short arm of the first subtelocentric pair. The fluorochrome CMA3 visualized bands in the short arm of the first subtelocentric pair for all the six species, while Acromyrmex rugosus and Acromyrmex niger also demonstrated in the other chromosomes. The AT-rich regions with differential staining using DAPI were not observed. 45S ribosomal genes were identified by FISH in the short arm of the first subtelocentric pair in Acromyrmex coronatus, Acromyrmex

  9. Characterization and development of EST-derived SSR markers in cultivated sweetpotato (Ipomoea batatas

    Directory of Open Access Journals (Sweden)

    Li Yujun

    2011-10-01

    Full Text Available Abstract Background Currently there exists a limited availability of genetic marker resources in sweetpotato (Ipomoea batatas, which is hindering genetic research in this species. It is necessary to develop more molecular markers for potential use in sweetpotato genetic research. With the newly developed next generation sequencing technology, large amount of transcribed sequences of sweetpotato have been generated and are available for identifying SSR markers by data mining. Results In this study, we investigated 181,615 ESTs for the identification and development of SSR markers. In total, 8,294 SSRs were identified from 7,163 SSR-containing unique ESTs. On an average, one SSR was found per 7.1 kb of EST sequence with tri-nucleotide motifs (42.9% being the most abundant followed by di- (41.2%, tetra- (9.2%, penta- (3.7% and hexa-nucleotide (3.1% repeat types. The top five motifs included AG/CT (26.9%, AAG/CTT (13.5%, AT/TA (10.6%, CCG/CGG (5.8% and AAT/ATT (4.5%. After removing possible duplicate of published EST-SSRs of sweetpotato, a total of non-repeat 7,958 SSR motifs were identified. Based on these SSR-containing sequences, 1,060 pairs of high-quality SSR primers were designed and used for validation of the amplification and assessment of the polymorphism between two parents of one mapping population (E Shu 3 Hao and Guang 2k-30 and eight accessions of cultivated sweetpotatoes. The results showed that 816 primer pairs could yield reproducible and strong amplification products, of which 195 (23.9% and 342 (41.9% primer pairs exhibited polymorphism between E Shu 3 Hao and Guang 2k-30 and among the 8 cultivated sweetpotatoes, respectively. Conclusion This study gives an insight into the frequency, type and distribution of sweetpotato EST-SSRs and demonstrates successful development of EST-SSR markers in cultivated sweetpotato. These EST-SSR markers could enrich the current resource of molecular markers for the sweetpotato community and would

  10. A novel educational tool for teaching ocular ultrasound

    Directory of Open Access Journals (Sweden)

    Mustafa MS

    2011-06-01

    Full Text Available MS Mustafa1, J Montgomery2, HR Atta11Department of Ophthalmology, Aberdeen Royal Infirmary, UK; 2Medi-CAL, College of Life Sciences and Medicine, University of Aberdeen, Foresterhill, Aberdeen, UKAbstract: Ocular ultrasound is now in increasing demand in routine ophthalmic clinical practice not only because it is noninvasive but also because of ever-advancing technology providing higher resolution imaging. It is however a difficult branch of ophthalmic investigations to grasp, as it requires a high skill level to interface with the technology and provide accurate interpretation of images for ophthalmic diagnosis and management. It is even more labor intensive to teach ocular ultrasound to another fellow clinician. One of the fundamental skills that proved difficult to learn and teach is the need for the examiner to “mentally convert” 2-dimensional B-scan images into 3-dimensional (3D interpretations. An additional challenge is the requirement to carry out this task in real time. We have developed a novel approach to teach ocular ultrasound by using a novel 3D ocular model. A 3D virtual model is built using widely available, open source, software. The model is then used to generate movie clips simulating different movements and orientations of the scanner head. Using Blender, Quicktime motion clips are choreographed and collated into interactive quizzes and other pertinent pedagogical media. The process involves scripting motion vectors, rotation, and tracking of both the virtual stereo camera and the model. The resulting sequence is then rendered for twinned right- and left-eye views. Finally, the twinned views are synchronized and combined in a format compatible with the stereo projection apparatus. This new model will help the student with spatial awareness and allow for assimilation of this awareness into clinical practice. It will also help with grasping the nomenclature used in ocular ultrasound as well as helping with localization of

  11. EDITORIAL: A support for prospective nanomaterials A support for prospective nanomaterials

    Science.gov (United States)

    Demming, Anna

    2011-01-01

    , often touted as a pioneer of a 'bottom-up' approach to nanotechnology, once said 'I was born not knowing and have had only a little time to change that here and there'. In a similar sense, what we do not yet know and understand about the ability to create and manipulate nanosystems is apparently infinite, but as can also be acceded in the case of Richard Feynman, the 'little' we have had time learn so far holds more than a little promise. References [1] Glass R, Möller M and Spatz J P 2003 Nanotechnology 14 314 [2] Kuzyk A, Laitinen K T and Törmä P 2009 Nanotechnology 20 235305 [3] Williams S M, Rodriguez K R, Teeters-Kennedy S, Shah S, Rogers T M, Stafford A D and Coe J V 2004 Nanotechnology 15 S495 [4] Bini T B, Gao S, Tan T C, Wang S, Lim, A, Hai L B and Ramakrishna S 2004 Nanotechnology 15 1459 [5] Yang F, Murugan R, Wang S and Ramakrishna S 2005 Biomaterials 26 2603-10 [6] Tampieri A, Landi E, Valentini F, Sandri M, D'Alessandro T, Dediu V and Marcacci M 2011 Nanotechnology 22 015104 [7] Gross A F, Ahn C C, Van Atta S L, Liu P and Vajo J J 2009 Nanotechnology 20 204005 [8] Zhang S, Gross A F, Van Atta S L, Lopez M, Liu P, Ahn C C, Vajo J J and Jensen C M 2009 Nanotechnology 20 204027

  12. 基于高通量测序的思茅松微卫星位点的特征分析%Characteristic analysis of microsatellite in Pinus kesiya var. langbianensis by using high-throughput sequencing

    Institute of Scientific and Technical Information of China (English)

    邓丽丽; 李德龙; 蔡年辉; 周军; 孙琪; 唐红燕; 王大玮; 许玉兰

    2016-01-01

    以思茅松针叶为材料,采用 Illumina Hiseq2000平台测序,得到121882条无冗余的序列,对这些序列进行 SSR 位点搜索,共获得3534个 SSR 位点,出现频率为2.9%,分布平均距离25kb。所搜索的 SSR 以单核苷酸重复类型最多,其次为三核苷酸和二核苷酸,而四、五、六核苷酸重复类型较少(<1%)。单核苷酸重复类型中以 A/T 基元较丰富(43.58%);二核苷酸中出现频率最高的是 AT/TA 基元(14.04%),AG/CT 次之, AC/GT 和 CG/CG 较低;三核苷酸重复类型中 AAG/CTT 最多,AGC/CTG 和 AGG/CCT 次之,以 CCG/CGG、ACG/CGT 和 ACT/AGT 较少(<1%);四、五、六核苷酸类型中各重复基元相差不大,均较少。SSR 数量随对应的重复类型重复次数的增加而降低,也随重复区段碱基长度的增加而降低。%Needle sample of Pinus kesiya var. langbianensis was sequenced with high-throughput sequencing technology (Illumina Hiseq 2000). In total 121 882 transcripts of Pinus kesiya var. langbianensis. were screened using MISA software. 3534 SSRs were identified, and the frequency of SSR was 2.9% and mean distribution density was 25 kb. The mono-nucleotide repeats were the highest, followed by tri-nucleotide and di-nucleotide repeat types. The tetra-nucleotide, petra-nucleotide and hexa-nucleotide were all less than 1%. Among the mononucleotide repeats, the A/T repeats motifs were the highest frequency (43.58%). AT/AT was the most frequent repeat motifs in di-nucleotide repeats (14.04%), followed by AG/CT. AC/GT and CG/CG were minimum. AAG/CTT repeats motifs was the highest in tri-nucleotide followed by AGC/CTG and AGG/CCT, while CCG/CGG, ACG/CGT and ACT/AGT were lowest ( < 1%). The repeat motifs were very few in tetra-nucleotide, petra-nucleotide and hexa-nucleotide and had no obvious differences. The SSR number of decreased with the increased number of repeats and length of repeats.

  13. Effect of dietary fiber in lowering serum glucose and body weight in sprague dawley rats

    Directory of Open Access Journals (Sweden)

    Muhammad Imran Chohan

    2011-08-01

    Full Text Available Introduction:The present study evaluated the hypoglycemic perspectives and weight loss significance of dietary fiber. Dietary fiber was supplemented in commercial wheat flour (atta for the preparation of chapaties, a staple diet of South Asia. Male Sprague Dawley rats (n = 100 were randomly divided into 4 diet groups (n = 25 per group. The control group was fed basal diet that included commercial wheat flour chapati, cornstarch, corn oil, salt and vitamin mixture in such a way that 10% of the protein was available from the final diet. To the basal diet of other 3 groups, chapaties supplemented with 2% guar gum (GG 2%, 3% guar gum (GG 3% and 5% chickpea + 1% guar gum (CP5%+GG1% were added, respectively. All diets were fed to the rats for a period of 8 weeks to perceive the impact of respective compositions. Rats fed on CP 5% + GG1%, showed maximum glucose reduction (14.57% followed by GG 3% (11.64% and GG 2% (9.60% as compared to control diet. Likewise, rats fed on 3% GG showed maximum decline (7.90% in body weight. It was concluded that chapaties prepared from selected treatments provide an additional dietary fiber that could be supportive for diabetic and obese individuals.Results:The results indicated that addition of dietary fiber influenced the physical characteristics of chapati non-significantly. Maximum glucose concentration was found to be 112.50 mg/dL in control group followed by 101.70 and 99.41 mg/dL in groups fed on guar gum 2% and guar gum 3%, respectively. Lowest glucose concentration (96.11 mg/dL was observed in rats fed on the combination of chickpea 5 %+ guar gum 1%. Maximum serum protein concentration was found to be 6.39 g/dL in rats fed on combination of chickpea 5 % + guar gum 1% whilst the remaining three groups showed non significant variations with respect to each other. Means for serum Functional Foods in Health and Disease 2011; 8:261-278 protein were 6.33, 6.30 and 6.32 g/dL for control, guar gum 3%, and guar gum 2

  14. 欧美投资者与东道国争端解决条款的最新动向%The Trend of Investor-State Dispute Settlement Provisions Drafted by Europe and America

    Institute of Scientific and Technical Information of China (English)

    宋俊荣

    2015-01-01

    From the macroscopic perspective , the current investor-state dispute settlement provisions drafted by EU and U.S.share the same trend, that is, while strengthening the protection of the interests of the host country , we should seek to the balance between protecting the private interests of investors and the maintenance of the public interests of the host country.They also pursue the same values when drafting the specific rules , including encouraging parties to settle the dis-putes by amicable methods , restricting investors′abuse of their rights to litigate , enhancing transparency and third par-ties′involvement, and reinforcing the regulation and supervision of arbitral tribunals and arbitrators .However, EU atta-ches more importance to ensuring host states′right to regulate than U .S.in current Sino-EU and Sino-U.S.BIT negoti-ations, China should use what EU and U .S.want regarding ISDS provisions as a bargaining chip to secure their compro-mise on other provisions more beneficial to China .Moreover, China should adopt practical measures to improve the ability of our government and investors to participate in international investment arbitration.%从宏观的角度来看, 美国和欧盟的投资者与东道国之间争端解决条款有着共同的发展趋势, 即在强化对东道国权益保护的同时, 谋求在保护投资者私人利益和维护东道国公共利益之间的平衡. 在具体规则的设计上, 它们也有着共同的价值追求, 包括鼓励通过友好方式解决争端、 限制投资者对诉权的滥用、 提升透明度、 强化第三方参与、 增强对仲裁庭和仲裁员的约束和监督等. 不过, 欧盟在总体上更加注重对东道国利益的考量. 在目前的中美和中欧BIT 谈判中, 我国可以将欧美在ISDS条款上的要价作为谈判筹码, 换取欧美在其他有利于我国的条款上的让步. 此外, 我国还应采取切实措施提升我国政府和企业参与国际投资仲裁的能力.

  15. Meliponini neotropicais: o gênero Partamona Schwarz, 1939 (Hymenoptera, Apidae, Apinae - bionomia e biogeografia Neotropical Meliponini: the genus Partamona Schwarz, 1939 (Hymenoptera, Apidae, Apinae - bionomy and biogeography

    Directory of Open Access Journals (Sweden)

    João M. F. Camargo

    2003-01-01

    termitaria, such as cavities and crevices in walls, among roots of epiphytes and in bases of palm leaves, in abandoned bird nests, under bridges, and in other protected places, except P. peckolti that occasionally occupies termite nests. In South America, on the eastern side of the Andes, only P. epiphytophila and P. helleri nest among roots of epiphytes and other substrates, non-associated with termitaria. All other species studied (P. batesi, P. gregaria, P. pearsoni, P. ferreirai, P. chapadicola, P. nhambiquara, P. vicina, P. mourei, P. auripennis, P. combinata, P. cupira, P. mulata, P. ailyae, P. seridoensis, P. criptica and P. rustica nest inside active termite nests, whether epigeous or arboreous. The only species that builds obligate subterranean nests, associated or not with termite or ant nests (Atta spp. is P. testacea. Nests of Partamona have one vestibular chamber (autapomorphic for the genus closely adjacent to the entrance, filled with a labyrinth of anastomosing pillars and connectives, made of earth and resins. One principal chamber exists for food and brood, but in some species one or more additional chambers are filled with food storage pots. In nests of P. vicina, there is one atrium or "false nest", between the vestibule and the brood chamber, which contains involucral sheaths, cells and empty pots. All structures of the nest are supported by permanent pillars made of earth and resins (another autapomorphy of the genus. The characters concerning nesting habits were coded and combined with morphological and biogeographic data, in order to hypothesize the evolutive scenario of the genus using cladistic methodology. The phylogenetic hypothesis presented is the following: (((((P. bilineata (P. grandipennis, P. xanthogastra (P. orizabaensis, P. peckolti (P. aequatoriana, P. musarum P. epiphytophila, P. yungarum, P. subtilis, P. vitae (((((P. testacea (P. mourei, P. vicina (P. nigrior (P. auripennis, P. combinata (P. ferreirai (P. pearsoni (P. gregaria (P

  16. 利用高通量测序技术分析核桃基因组微卫星特征1)%Microsatellite Characters in Juglans regia L.Genome by High Throughput Sequencing Technology

    Institute of Scientific and Technical Information of China (English)

    廖卓毅; 马秋月; 戴晓港; 张得芳; 李淑娴

    2014-01-01

    We sequenced the partially genome of Juglans regia with a 454-high-throughput sequencer and analyzed the character-istics of microsatellites based on the obtained sequences.Totally, we sequenced 104.5 Mb genome sequences of J.regia and detected 9 787 microsatellites (SSRs) in the assembled genome sequence.Among these SSRs, the hexanucleotied re-peats are the most abundant (5 883), accounting for 60.11%of the repetition sequence.Monomers (1 289) and Tetranu-cleotide (889) are the second and third abundant.There are 768 dinucleotide, 549 trinucleotide and 409 pentanucleotide, accounted for 7.85%, 5.61%and 4.18% of repetitive sequences, respectively.For the composition of microsatellites, A/T repeats are the most frequent motifs in mononucleotide repeats, and AT/TA, AG/TC repeats are the richest in dinu-cleotide repeats, while AAN, AAAN and AAAAAN repeats are dominant in tri-, tetra-and hexanucleotide repeats.For pentanucleotide, AGATG and AAAAT are the main repeats.In the microsatellite sequence repeats of Juglans, nucleotide A/T has a large content, while the C/G content is relatively small.In Juglans genome, the second type of SSRs (length<20bp ) is predominant .%利用454高通量测序技术对核桃( Juglans regia)基因组进行了部分测序,并利用测得的序列进行核桃基因组微卫星特征分析。结果表明:研究共测得了104.5 Mb的核桃基因组序列,经序列组装得到了9787个微卫星重复序列。其中六碱基重复类型的重复数目最多,共5883个,占重复序列总数的60.11%;其次是单碱基重复类型(1289个)和四碱基重复类型(889个),分别占重复序列总数的13.17%和9.07%;另外二碱基重复768个,三碱基重复549个,五碱基409个,分别占重复序列总数的7.85%、5.61%和4.18%。在单碱基重复类型中,重复单元最多的为A/T;二碱基重复中,AT/TA和AG/CT为主要优势重复类型;三碱基、四碱基和六碱

  17. MEMORIAS III Encuentro Científico de Estudiantes de Biología

    Directory of Open Access Journals (Sweden)

    Acta Biológica Colombiana

    2003-12-01

    de biomasa por una colonia de atta laevigatasmith 1958 (hymenoptera: formicidae en los Llanos Orientales (Puerto López, Meta, Colombia / Manejo ex situde crías de crocodylus intermedius(crocodylidae, una experiencia como estudiante de práctica académica / Caracterización del llamado de advertencia de colostethus bocagei(amphibia: dendrobatidae en el municipio de Ibagué, Colombia / Caracterización del llamado de advertencia de colostethus bocagei(amphibia: dendrobatidae en el municipio de Ibagué, Colombia / Uso etnomédico de algunas especies vegetales del departamento del Chocó, Colombia / Morfología y herbivoría en las especies del género tococa(melastomataceae con mirmecomacios / Fauna Asociada a la Medicina Tradicional del Departamento Del Chocó, Colombia / Hongos alucinógenos: el desconocimiento cultural de su consumo / Relación insecto-hongo: desarrollo de dípteros en panaeolus foenisecii (basidiomycotina-agariclaes / Estudio preliminar de algunos aspectos biológicos de hoplias malabaricusbloch 1794 (Quicharo en la microcuenca de Cabí, Chocó, Colomba / Composición y estructura de la vegetación terrestre aledaña al Río Gaira (Departamento Del Magdalena, Colombia / Relaciones de herbivoría por insectos sobre Lantana sp. (Verbenacea, Piper sp.(Piperaceae y Miconia sp.(Asteraceae en Moniquirá (Boyacá, Colombia.

  18. MFGA-IDT2 workshop: Astrophysical and geophysical fluid mechanics: the impact of data on turbulence theories

    Science.gov (United States)

    Schertzer, D.; Falgarone, E.

    very large scale of the Universe. The presentations and the round table at the end of the workshop pointed out the following: - the necessity of this type of confrontation which makes intervene numerical simulations, laboratory experiments, phenomenology as well as a very large diversity of geophysical and astrophysical data, - presumably a relative need for new geophysical data, whereas there have been recent astrophysical experiments which yield interesting data and exciting questions; - the need to develop a closer intercomparison between various intermittency models (in particular Log-Poisson /Log Levy models). Two main questions were underlined, in particular during the round table: - the behaviour of the extremes of intermittency, in particular the question of divergence or convergence of the highest statistical moments (equivalently, do the probability distributions have algebraic or more rapid falloffs?); - the extension of scaling ranges; in other words do we need to divide geophysics and astrophysics in many small (nearly) isotropic subranges or is it sufficient to use anisotropic scaling notions over wider ranges? 4 The contributions in this special issue Recalling that some of the most useful insights into the nature of turbulence in fluids have come from observations of geophysical flows, Van Atta gives a review of the impacts of geophysical turbulence data into theories. His paper starts from Taylor's inference of the nearly isotropy of atmospheric turbulence and the corresponding elegant theoretical developments by von Karman of the theory of isotropic turbulence, up to underline the fact that the observed extremely large intermittency in geophysical turbulence also raised new fundamental questions for turbulence theory. The paper discusses the potential contribution to theoretical development from the available or currently being made geophysical turbulence measurements, as well as from some recent laboratory measurements and direct numerical