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  1. Reavaliação taxonômica de Colletotrichum guaranicola Albuq. agente causal da antracnose do guaranazeiro Taxonomic reavaluation of Colletotrichum guaranicola Albuq. causal agent of guarana anthracnose

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    Jânia Lília da Silva Bentes

    2004-01-01

    Full Text Available Foi realizada uma reavaliação morfológica de estruturas reprodutivas e de infecção do agente causal da antracnose do guaranazeiro (Paullinia cupana var. sorbilis, visando confirmar a identidade do patógeno. Os resultados reforçam o reconhecimento da espécie Colletotrichum guaranicola Albuq., como um novo taxon dentro do gênero Colletotrichum.A morphological study of reproductive and infection structures of the anthracnosis fungus of guaranazeiro (Paullinia cupana var. sorbilis, has confirmed the pathogen identity as Colletotrichum guaranicola Albuq., a new specie in the Colletotrichum genera.

  2. ITS-rDNA phylogeny of Colletotrichum spp. causal agent of apple Glomerella leaf spot Filogenia por ITS-rDNA de Colletotrichum spp., agente causal da mancha foliar da Gala em macieira

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    Diorvania Ribeiro Giaretta

    2010-04-01

    Full Text Available Several diseases have affected apple production, among them there is Glomerella leaf spot (GLS caused by Colletotrichum spp. The first report of this disease in apple was in plants nearby citrus orchards in São Paulo State, Brazil. The origin of this disease is still not clear, and studies based on the molecular phylogeny could relate the organisms evolutionarily and characterize possible mechanisms of divergent evolution. The amplification of 5.8S-ITS (Internal Transcribed Spacer of rDNA of 51 pathogenic Colletotrichum spp. isolates from apples, pineapple guava and citrus produced one fragment of approximately 600 bases pairs (bp for all the isolates analyzed. The amplified fragments were cleaved with restriction enzymes, and fragments from 90 to 500bp were obtained. The sequencing of this region allowed the generation of a phylogenetic tree, regardless of their hosts, and 5 isolated groups were obtained. From the "in silico" comparison, it was possible to verify a variation from 93 to 100% of similarity between the sequences studied and the Genbank data base. The causal agent of GLS is nearly related (clustered to isolates of pineapple guava and to the citrus isolates used as control.A produção de maçã vem sendo comprometida pela ocorrência de muitas doenças, entre as quais se destaca a Mancha Foliar de Glomerella (MFG, causada por Colletotrichum spp. O primeiro relato dessa doença em maçã foi registrado em plantas próximas a pomares de citrus no Estado de São Paulo, Brasil. A origem da MFG ainda não está bem clara, e estudos baseados na filogenia permitirão relacionar o organismo evolutivamente, possibilitando caracterizar possíveis mecanismos divergentes de evolução. A amplificação da região 5.8S-ITS (espaçador interno transcrito do rDNA de 51 isolados de Colletotrichum patogênicos em de maçã, goiabeira serrana e citrus produziu um fragmento de aproximadamente 600 pares de bases (pb para todos os isolados analisados

  3. Diversidade fenotípica e patogênica de Colletotrichum, agente causal da antracnose em mangueira, e identificação de espécie

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    I.M.R.S. Serra; R.S.B. Coelho; G.M.G. Ferraz; A.V.V. Montarroyos; D.S. Silva

    2011-01-01

    O presente trabalho teve como objetivo estudar a diversidade fenotípica e patogênica de 40 isolados de Colletotrichum obtidos de mangueira no Nordeste do Brasil e identificar diferentes espécies desse fitopatógeno, agente causal de antracnose, através da análise da seqüência da região ITS do rDNA. Quanto à caracterização morfológica e cultural, as colônias dos isolados apresentaram diversidade em relação à cor e aspecto, sendo mais comum à cor branco-cinza, característica de Colletotrichum gl...

  4. Genes diferencialmente expressos em cana-de-açúcar inoculada com Xanthomonas albilineans, o agente causal da escaldadura da folha Diferential gene expression in sugar cane infected with Xanthomonas albilineans, causal agent of leaf scald

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    Karina Maia Dabbas

    2006-09-01

    Full Text Available A escaldadura da folha, causada pela bactéria Xanthomonas albilineans colonizadora do xilema, é uma das principais doenças da cana-de-açúcar. A sintomatologia na fase crônica é caracterizada principalmente pelo aparecimento de uma faixa branca paralela à nervura central da folha, que evolui até queimar totalmente, sendo também observado brotação de gemas laterais no colmo. Neste trabalho, a técnica de macroarranjos de cDNA foi empregada para o estudo da expressão de 3.575 ESTs (espressed sequence tags em folhas de cana-de-açúcar. Foram utilizadas duas variedades, uma resistente (SP82-1176 e outra suscetível (SP78-4467 a Xanthomonas albilineans as quais foram infectadas mecanicamente por ferimentos. As membranas dos macroarranjos foram confeccionadas a partir de ESTs de bibliotecas de folha e cartucho de cana-de-açúcar provenientes do projeto SUCEST e hibridizadas contra sondas de cDNA de plantas infectadas e controle marcadas com isótopos radioativos. Analisando os resultados dos macroarranjos foi possível verificar um comportamento diferenciado para cada variedade durante o ataque do patógeno. Após realizadas análises estatísticas identificamos na variedade resistente ESTs com expressão induzida relacionadas com biossíntese de isoprenoides, proteínas LRR transmembrânica, "ziper" de leucina, lignificação, tolerância ao frio, diferenciação de plastídeos, sistemas de defesa e de adaptação da planta ao meio ambiente. As ESTs reprimidas na variedade resistente foram àquelas relacionadas com genes responsáveis pela síntese de proteínas do controle da expansão da parede celular, detoxificação e transporte de auxina. Na variedade susceptível foram reprimidas ESTs relacionadas a genes de proteínas das respostas de defesa da planta, biossíntese de Etileno e regulação da transcrição.The leaf scald disease, caused by the xylem-invading pathogen Xanthomonas albilineans, is one of the most devastating

  5. Diversidade fenotípica e patogênica de Colletotrichum, agente causal da antracnose em mangueira, e identificação de espécie

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    I.M.R.S. Serra

    2011-03-01

    Full Text Available O presente trabalho teve como objetivo estudar a diversidade fenotípica e patogênica de 40 isolados de Colletotrichum obtidos de mangueira no Nordeste do Brasil e identificar diferentes espécies desse fitopatógeno, agente causal de antracnose, através da análise da seqüência da região ITS do rDNA. Quanto à caracterização morfológica e cultural, as colônias dos isolados apresentaram diversidade em relação à cor e aspecto, sendo mais comum à cor branco-cinza, característica de Colletotrichum gloeosporioides. Não foram observadas variações expressivas na morfologia dos 40 isolados. Os conídios apresentaram-se, predominantemente, hialinos e unicelulares, com formato variando de bastonete para cilíndrico. Todos os isolados produziram apressórios variados em formato e quantidade e apenas 10 isolados apresentaram setas. Para efeito do crescimento micelial e taxa de crescimento foi possível classificar os isolados em sete grupos. Vinte e dois isolados exibiram taxa de crescimento >10mm/dia, considerada típica da espécie C. gloeosporioides. Os isolados foram patogênicos em folhas destacadas de mangueira, induzindo sintomas de antracnose, na forma de manchas escuras levemente deprimidas, e apresentando variações quanto à agressividade. Na identificação específica, baseada na análise da seqüência ITS do DNA ribossomal, 36 isolados amplificaram com o oligonucleotídeos CgInt, específico para C. gloeosporioides e o ITS4, Os isolados CM1, CM4, CM5 e CM10, não amplificaram produtos para nenhum dos oligonucleotídeos específicos, sendo identificados como Colletotrichum spp. Os resultados desse trabalho demonstraram que isolados de Colletotrichum, obtidos de mangueira, apresentam ampla variabilidade morfofisiológica e patogênica. E que, possivelmente, existe mais de uma espécie de Colletotrichum que causa antracnose em mangueira no Nordeste do Brasil.

  6. Controle alternativo de Colletotrichum acutatum agente causal da queda prematura dos frutos cítricos Alternative control of Colletotrichum acutatum, causal agent of postbloom fruit drop of citrus

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    Katia Cristina Kupper

    2009-12-01

    Full Text Available A queda prematura dos frutos cítricos (QPFC, causada por Colletotrichum acutatum, dados os grandes prejuízos que têm causado aos produtores, constitui-se numa doença de grande importância econômica. O controle da doença é feito predominantemente mediante uso de fungicidas, que eleva o custo de produção e afeta negativamente o meio ambiente. Diante disso, este trabalho teve por objetivo buscar um método alternativo de controle da QPFC, mediante o uso de agentes de biocontrole ou de biofertilizantes. Diferentes concentrações de biofertilizantes (originários de duas fontes distintas e denominados de Bio1 e Bio 2; três isolados de Bacillus subtilis (ACB-69; 72 e 77 e três isolados de Trichoderma spp. (ACB-14; 37 e 39 foram testados, isoladamente ou em combinação, sob condições de laboratório, quanto à capacidade inibitória da germinação de conídios de C. acutatum. Estudaram-se, ainda, a produção de metabólitos termoestáveis por B. subtilis e o efeito sobre a germinação do patógeno. Quinze isolados de B. subtilis foram testados quanto à capacidade de prevenir a infecção por C. acutatum em flores destacadas de lima- ácida 'Tahiti' e, no campo, foram instalados dois experimentos, visando a testar ACBs e biofertilizantes no controle da doença. Verificou-se que o isolado ACB-72 (B. subtilis e ACB-37 (T. pseudokoningii foram os que mais inibiram a germinação do patógeno. Quanto à produção de metabólitos termoestáveis, ACB-69 e 77 foram os mais eficientes em produzir substâncias antifúngicas, e em quantidades suficientes para inibirem a germinação do patógeno. A mistura dos quatro isolados de Bacillus (ACBs: 69; 72; 77 e AP3 foi o que apresentou maior porcentagem de inibição (73%. Os biofertilizantes (Bio1 e Bio2, em concentrações acima de 10% e, quando em associação com isolados de Trichoderma spp., promoveram maiores inibições na germinação de C. acutatum. Em testes com flores destacadas

  7. Heliconia psittacorum: hospedeira de Mycosphaerella fijiensis, agente causal da sigatoka-negra da bananeira First reporter of Mycosphaerella fijiensis on Heliconia psittacorum leaves

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    Luadir Gasparotto; J. Clério R. Pereira; Urben, Arailde F.; Rogério E Hanada; Mirza C. N. Pereira

    2005-01-01

    Em setembro de 2003, em Manaus, Amazonas, foram observadas manchas foliares, muito semelhantes àquelas de sigatoka-negra causada por Mycosphaerella fijiensis em folhas de Heliconia psittacorum. Efetuou-se o isolamento do patógeno e, para o teste de patogenicidade, foi utilizada a técnica de inoculação cruzada com os isolados de H. psittacorum e de bananeira (Musa spp.) da cv. Prata Anã. Em ambas as espécies o teste foi positivo. Com o auxílio do microscópio óptico, da literatura disponível e ...

  8. Resistência de variedades comerciais de cana-de-açúcar ao agente causal do raquitismo-da-soqueira Resistance of sugarcane commercials cultivars to causal agent of ratoon stunting disease

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    Paulo Roberto Gagliardi; Luis Eduardo Aranha Camargo

    2009-01-01

    O raquitismo-da-soqueira (RSD), causado pela bactéria Leifsonia xyli subsp. xyli, é uma das mais importantes doenças da cana-de-açúcar nas regiões produtoras do mundo. O presente trabalho teve como objetivo avaliar o grau de resistência de 10 variedades comerciais RB de cana-de-açúcar mais a variedade CB 49-260, a qual foi incluída como padrão suscetível. O trabalho visou avaliar os danos amostrados em campo pelo peso das parcelas em função da relação entre a produtividade de parcelas inocula...

  9. Resistência de variedades comerciais de cana-de-açúcar ao agente causal do raquitismo-da-soqueira Resistance of sugarcane commercials cultivars to causal agent of ratoon stunting disease

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    Paulo Roberto Gagliardi

    2009-07-01

    Full Text Available O raquitismo-da-soqueira (RSD, causado pela bactéria Leifsonia xyli subsp. xyli, é uma das mais importantes doenças da cana-de-açúcar nas regiões produtoras do mundo. O presente trabalho teve como objetivo avaliar o grau de resistência de 10 variedades comerciais RB de cana-de-açúcar mais a variedade CB 49-260, a qual foi incluída como padrão suscetível. O trabalho visou avaliar os danos amostrados em campo pelo peso das parcelas em função da relação entre a produtividade de parcelas inoculadas e não inoculadas artificialmente com a bactéria. Os resultados mostraram que as variedades RB 72 454, RB 83 5486, RB 86 7515, RB 92 5211, RB 92 5268, RB 92 5345, RB 92 8064 e a variedade padrão CB 49-260 comportaram-se como variedades suscetíveis. A variedade RB 85 5156 comportou-se como de resistência intermediária e apenas as variedades RB 85 5453 e RB 85 5536 comportaram-se como tolerantes.Ratoon stunting disease (RSD caused by bacteria Leifsonia xyli subsp. xyli is one of the most economically important disease of sugarcane worldwide. The present survey had objective to evaluate the resistance of 10 RB commercial cultivars of sugarcane including CB 49-260 as a susceptible standard. The study evaluated the correlating the damages presented for overhauls productivity of inoculate and non inoculate parcels with the bacteria. The results showed that varieties RB 72 454, RB 83 5486, RB 86 7515, RB 92 8064, RB 92 5211, RB 92 5345 and RB 92 5268 were susceptible. RB 85 5156 had a intermediary resistance and varieties RB 85 5453 and RB 85 5536 both showed tolerant behavior.

  10. Phytophthora palmivora, agente da podridão de raiz e frutos de mamoeiro no Estado de Alagoas Phytophthora palmivora, causal agent of root and fruit rots of papaya in the State of Alagoas, Brazil

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    Juliana Paiva Carnaúba

    2006-04-01

    Full Text Available O mamoeiro (Carica papaya é uma das mais importantes fruteiras tropicais, e seus frutos contribuem com uma produção de 1,65 milhão de toneladas por ano para o Brasil. Um isolado de Phytophthora sp. obtido de frutos de mamoeiro da cultivar Havaí, em Alagoas, foi caracterizado morfologicamente e sua patogenicidade foi confirmada em frutos e mudas deste hospedeiro. Em meio suco V-8, os esporangióforos apresentaram-se delgados, simples ou pouco ramificados, enquanto os esporângios se apresentaram ovóides a elipsóides, proeminentemente papilados e um pedicelo curto na porção basal, medindo em média 37,68 x 27,52 mm. Através das características apresentadas pelo isolado e os sintomas induzidos, o agente causal foi identificado como Phytophthora palmivora. Apesar de essa doença já ocorrer em outros estados, como Bahia, Espírito Santo, São Paulo, Pernambuco e Pará, este é o primeiro relato de Phytophthora palmivora em mamoeiro no Estado de Alagoas.The papaya (Carica papaya is one of the most important tropical fruit crops and its fruit contribute with a production of 1.65 millions tons/year in Brazil. An isolated of Phytophthora sp. gotten from papaya fruits cv. Hawaii, in the state of Alagoas, was characterized morphologically and its pathogenicity to this fruits and seedling was confirmed. In a V-8 medium, the sporangiophores presented to be slim, simple or little ramified, while the sporangia presented ovoid to ellipsoid, prominently papillae and one short pedicel in the basal portion, measuring in average 37,68 x 27,52 (m. Through the characteristics presented by the isolated and the induced symptoms, the causal agent was identified as Phytophthora palmivora. Despite of this disease already occurring in other states like in Bahia, Espirito Santo, São Paulo, Pernambuco and Pará, this is the first report of Phytophthora palmivora on papaya in the state of Alagoas, Brazil.

  11. Reação de cultivares de batata a Streptomyces scabies, agente causal da sarna comum profunda Reaction of potato cultivars to Streptomyces scabies, causal agent of deep common scab

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    Ivan Herman Fischer

    2009-09-01

    Full Text Available Este trabalho visou caracterizar quanto a critérios morfológicos e fisiológicos isolados de Streptomyces causadores de sarna comum profunda em batata; avaliar o comportamento de cultivares em relação à doença e a variação na agressividade entre os isolados da bactéria. Os isolados de Streptomyces apresentaram coloração cinza em meio extrato de levedura e malte e cadeias de esporos espiraladas, produzidas sobre um micélio aéreo. Ocorreu produção de melanina em meio de tirosina-ágar e a utilização de oito fontes de carbono recomendadas, propriedades estas que correspondem às descritas para S. scabies. Batatas-semente sadias de seis cultivares foram plantadas em substrato infestado com seis isolados de S. scabies separadamente e as plantas cultivadas em vasos e ambiente aberto. A severidade da doença foi estimada com auxílio de uma escala diagramática e avaliou-se o rendimento de tubérculos (g/planta. As cvs. Mondial e Jaete Bintje foram as mais resistentes à sarna comum com severidade média nos dois experimentos de 10,5% e 14,0%, respectivamente, seguidas por Asterix (17,4%, Ágata (21,8%, Monalisa (23,0% e Cupido (23,3%. A agressividade dos isolados variou quantitativamente, com severidade maior para o isolado M4 (34,7% e menor para o isolado M1 (6,2%. Redução da produção de tubérculos foi verificada na cv. Jaete Bintje, no primeiro experimento, e quando as cultivares foram infectadas pelos isolados A1, M2 e M3, no primeiro experimento, e pelo isolado M4, no segundo experimento.This work aimed to characterize the isolates of Streptomyces, responsible for deep common scab symptoms in potato, according to morphological and physiological criteria; to evaluate the resistance of potato cultivars to the disease and the aggressiveness of bacterium isolates. The Streptomyces isolates presented gray coloration on yeast extract and malt medium and spiral spore chains, produced on aerial hyphae. Production of melanina occurred

  12. Caracterização de isolados de Phytophthora drechsleri, agente causal da podridão mole de raízes de mandioca Characterization of Phytophthora drechsleri, the causal agent of cassava soft root rot

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    Maria de Fátima S. Muniz

    2006-04-01

    Full Text Available O presente trabalho teve como objetivo caracterizar nove isolados de Phytophthora sp. obtidos de mandioca (Manihot esculenta, através da morfologia e morfometria das estruturas propagativas e crescimento micelial em diferentes temperaturas e avaliar sua patogenicidade. Os esporângios produzidos em extrato de solo não esterilizado mostraram-se ovóides, não papilados, persistentes, formados em esporangióforos não ramificados ou em simpódio, com dimensões de 24,6 - 57,4 µ x 14,8 - 37,7 µm e relação comprimento/largura de 1,0 - 2,6. Os clamidósporos foram raros. Os oósporos obtidos em cultura monospórica em V8 ágar eram apleuróticos, com 13,1 - 34,4 µm de diâmetro. Oogônios mostraram-se esféricos e mediram 19,7 - 41,0 µm de diâmetro; anterídios anfígenos, com dimensões de 8,2 - 24,6 µm x 8,2 - 19,7 µm. O maior diâmetro das colônias ocorreu a 25 ºC em V8 ágar. Os isolados patogênicos às plantas e raízes destacadas de mandioca inoculados foram identificados como Phytophthora drechsleri.Nine Phytophthora isolates from cassava (Manihot esculenta were characterized based on morphology and morphometry of propagative structures, growth at 10, 15, 20, 25, 30 and 35 ºC, and by evaluating its pathogenicity. Sporangia produced on nonsterile soil extract were ovoid, nonpapillate and persistent, formed in a sympodium or unbranched sporangiophores, 24.6 to 57.4 µm long x 14.8 to 37.7 µm wide, and length-breadth ratio was 1.0 - 2.6. Chlamydospores were rarely observed. Oospores produced in single spore culture on V8 agar medium were aplerotic, and 13.1 to 34.4 µm in diameter. Antheridia were amphigynous, measuring 8.2 - 24.6 µ x 8.2 - 19.7 µ ; oogonia ranged from 19.7 to 41.0 µm in diameter. Culture growth was greatest at 25 ºC in V8 agar medium. The isolates that were pathogenic to plants and detached roots of cassava were identified as Phytophthora drechsleri Tucker.

  13. Efeito inibitório de extratos vegetais sobre Colletotrichum gloeosporioides - agente causal da podridão de frutos de mamoeiro

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    Ribeiro Luiz Fernando

    1999-01-01

    Full Text Available Extratos aquosos foram obtidos a partir de bulbilhos de alho, folhas de hortelã e mamona e frutos de pimenta. Após a incorporação destes extratos em BDA, obtendo-se concentrações de 100, 200, 500, 1000, 5000 e 10000 ppm, foi avaliado o crescimento e a produção de conídios de um isolado de Colletotrichum gloeosporioides, agente de podridão em frutos de mamoeiro. Os resultados demonstraram o efeito inibitório dos diferentes extratos a partir da concentração de 200 ppm. O extrato de alho inibiu o crescimento micelial, em porcentagens variáveis de 5,3 a 67,6%, porém não atuou de modo expressivo sobre a produção de conídios. Em contraposição, os extratos de hortelã, mamona e pimenta promoveram inibição menos acentuada do crescimento de micélio, porém reduziram drasticamente a produção de conídios em níveis variáveis de 41 a 84%, de acordo com as concentrações crescentes dos mesmos. As propriedades fungitóxicas detectadas nos extratos utilizados no ensaio evidenciaram o uso potencial dos mesmos como alternativa aos métodos físicos e químicos convencionalmente usados para o controle da doença.

  14. Caracterização molecular e patogênica de isolados de Xanthomonas albilineans (Ashby Dowson, agente causal da escaldadura das folhas da cana-de-açúcar Molecular and pathogenic characterization of isolates of Xanthomonas albilineans (Ashby Dowson, causal agent of sugarcane leaf scald

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    Mariana de Souza e Silva

    2007-12-01

    Full Text Available A escaldadura das folhas, causada pela bactéria Xanthomonas albilineans (Ashby Dowson, é uma das cinco doenças mais importantes da cana-de-açúcar e sua ocorrência reduz o rendimento e a longevidade da cultura. Variedades resistentes têm sido usadas para o controle, porém há evidências da ocorrência de variantes do patógeno. Em campos comerciais do Estado de São Paulo, tem sido observado que a mesma variedade de cana se apresenta como resistente em uma região e suscetível em outra, sugerindo a ocorrência de variantes na população do patógeno. Assim, o objetivo deste trabalho foi investigar a presença de diversidade genética da bactéria em áreas comerciais. Um total de 50 isolados foram obtidos em cultura pura a partir de plantas sintomáticas coletadas em Piracicaba (SP, Jaú (SP, região de Ribeirão Preto (SP e Iturama (MG. Os isolados foram confirmados como pertencentes à espécie X. albilineans por meio de características de colônias, serologia e PCR com 'primers' específicos. Para caracterização da diversidade genética, foi usado o método de Rep-PCR, a partir do DNA extraído de cada isolado. Oito isolados, provenientes dos diferentes grupos identificados por rep-PCR, foram usados em testes de patogenicidade, por meio de inoculação em duas variedades de cana. Os resultados confirmaram todos os isolados como pertencentes à espécie X. albilineans. Por meio de rep-PCR, foi demonstrada diversidade genética entre os isolados, os quais foram separados em três grupos: um grupo composto somente pelos isolados de Piracicaba; um segundo, contendo todos os isolados amostrados em Jaú e na região de Ribeirão Preto, e um isolado de Iturama; e, no terceiro, somente dois isolados coletados em Iturama. Os testes de patogenicidade revelaram diferenças na agressividade entre isolados, porém sem relação com sua região de origem. Este trabalho revelou a ocorrência de diversidade genética e de agressividade dentro da

  15. Phytophthora palmivora, agente da podridão de raiz e frutos de mamoeiro no Estado de Alagoas Phytophthora palmivora, causal agent of root and fruit rots of papaya in the State of Alagoas, Brazil

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    Juliana Paiva Carnaúba; Márcio Félix Sobral; Daniela Cavalcanti de Medeiros Furtado; Izael Oliveira Silva; Kirley Michelly Marques da Silva; Edna Peixoto da Rocha Amorim

    2006-01-01

    O mamoeiro (Carica papaya) é uma das mais importantes fruteiras tropicais, e seus frutos contribuem com uma produção de 1,65 milhão de toneladas por ano para o Brasil. Um isolado de Phytophthora sp. obtido de frutos de mamoeiro da cultivar Havaí, em Alagoas, foi caracterizado morfologicamente e sua patogenicidade foi confirmada em frutos e mudas deste hospedeiro. Em meio suco V-8, os esporangióforos apresentaram-se delgados, simples ou pouco ramificados, enquanto os esporângios se apresentara...

  16. Causality

    Science.gov (United States)

    Pearl, Judea

    2000-03-01

    Written by one of the pre-eminent researchers in the field, this book provides a comprehensive exposition of modern analysis of causation. It shows how causality has grown from a nebulous concept into a mathematical theory with significant applications in the fields of statistics, artificial intelligence, philosophy, cognitive science, and the health and social sciences. Pearl presents a unified account of the probabilistic, manipulative, counterfactual and structural approaches to causation, and devises simple mathematical tools for analyzing the relationships between causal connections, statistical associations, actions and observations. The book will open the way for including causal analysis in the standard curriculum of statistics, artifical intelligence, business, epidemiology, social science and economics. Students in these areas will find natural models, simple identification procedures, and precise mathematical definitions of causal concepts that traditional texts have tended to evade or make unduly complicated. This book will be of interest to professionals and students in a wide variety of fields. Anyone who wishes to elucidate meaningful relationships from data, predict effects of actions and policies, assess explanations of reported events, or form theories of causal understanding and causal speech will find this book stimulating and invaluable.

  17. Fusarium oxysporum as causal agent of tomato wilt and fruit rot

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    Maja Ignjatov; Dragana Milošević; Zorica Nikolić; Jelica Gvozdanović-Varga; Dušica Jovičić; Gordana Zdjelar

    2012-01-01

    Tomatoes are parasitized by a number of pathogens, including Fusarium oxysporum f. sp. lycopersici, causal agent of fusarium wilt. Fresh vegetable fruits can be contaminated with various fungi that produce mycotoxins, which is an important issue for human health. The objective of this paper was to isolate, determine, and identify causal organisms of tomato wilt and fruit rot, based on the pathogens morphological and molecular characteristics. Samples of dis...

  18. Experimental and causal view on information integration in autonomous agents

    OpenAIRE

    Geiger, Philipp; Hofmann, Katja; Schölkopf, Bernhard

    2016-01-01

    The amount of digitally available but heterogeneous information about the world is remarkable, and new technologies such as self-driving cars, smart homes or the "internet of things" will further increase it. In this paper we examine certain aspects of the problem of how such heterogeneous information can be harnessed by intelligent agents. We first discuss potentials and limitations of some existing approaches, followed by two investigations. The focus of the first investigation is on using ...

  19. Executive Emotional System Disruption as Causal Agent in Frontal Lobishness among Abused Children

    Science.gov (United States)

    Naude, H.; Du Preez, C. S.; Pretorius, E.

    2004-01-01

    This article aims to explore Executive Emotional System (EES) disruption as causal agent in frontal lobishness among abused children. The "Revised Senior South African Individual Scale" (SSAIS-R) was used to assess a sample population of seventy-five male and female subjects between the ages of 8 years 0 months and 16 years 11 months who were…

  20. ‘Candidatus Liberibacter asiaticus’, Causal Agent of Citrus Huanglongbing, Is Reduced by Treatment with Brassinosteroids

    OpenAIRE

    Canales, Eduardo; Coll, Yamilet; Hernández, Ingrid; Portieles, Roxana; Rodríguez García, Mayra; López, Yunior; Aranguren, Miguel; Alonso, Eugenio; Delgado, Roger; Luis, Maritza; Batista, Lochy; Paredes, Camilo; Rodríguez, Meilyn; Pujol, Merardo; Ochagavia, María Elena

    2016-01-01

    Huanglongbing (HLB) constitutes the most destructive disease of citrus worldwide, yet no established efficient management measures exist for it. Brassinosteroids, a family of plant steroidal compounds, are essential for plant growth, development and stress tolerance. As a possible control strategy for HLB, epibrassinolide was applied to as a foliar spray to citrus plants infected with the causal agent of HLB, ‘Candidatus Liberibacter asiaticus’. The bacterial titers were reduced after treatme...

  1. Molecular detection of Monilinia fructigena as causal agent of brown rot on quince

    OpenAIRE

    Jovana Hrustić; Mila Grahovac; Milica Mihajlović; Goran Delibašić; Mirko Ivanović; Mihailo Nikolić; Brankica Tanović

    2012-01-01

    Species of the genus Monilinia are important causal agents of fruit rot on pome and stone fruits in Serbia. The pathogen is very harmful, especially on small properties and cottage plantations where intensive control measures are not applied. Quince is important host for the pathogens of this genus. During spring 2010, intensive occurrence of mummified fruits overwintering on branches of the quince was observed. The pathogen was isolated using standard phyt...

  2. Occupational Asthma: New Low-Molecular-Weight Causal Agents, 2000–2010

    Directory of Open Access Journals (Sweden)

    J. A. Pralong

    2012-01-01

    Full Text Available Background. More than 400 agents have been documented as causing occupational asthma (OA. The list of low-molecular-weight (LMW agents that have been identified as potential causes of OA is constantly expanding, emphasizing the need to continually update our knowledge by reviewing the literature. Objective. The objective of this paper was to identify all new LMW agents causing occupational asthma reported during the period 2000–2010. Methods. A Medline search was performed using the keywords occupational asthma, new allergens, new causes, and low-molecular-weight agents. Results. We found 39 publications describing 41 new LMW causal agents, which belonged to the following categories: drugs (n=12, wood dust (n=11, chemicals (n=8, metals (n=4, biocides (n=3, and miscellaneous (n=3. The diagnosis of OA was confirmed through SIC for 35 of 41 agents, peak expiratory flow monitoring for three (3 agents, and the clinical history alone for three (3 agents. Immunological tests provided evidence supporting an IgE-mediated mechanism for eight (8 (20% of the newly described agents. Conclusion. This paper highlights the importance of being alert to the occurrence of new LMW sensitizers, which can elicit OA. The immunological mechanism is explained by a type I hypersensitivity reaction in 20% of all newly described LMW agents.

  3. Effect of the lactoperoxidase system against three major causal agents of disease in mangoes.

    Science.gov (United States)

    Le Nguyen, Doan Duy; Ducamp, Marie-Noelle; Dornier, Manuel; Montet, Didier; Loiseau, Gérard

    2005-07-01

    The antibacterial activity of the lactoperoxidase system (LPS) on the growth of Xanthomonas campestris, the causal agent of bacterial black spot in mangoes, Botryodiplodia theobromae, the causal agent of stem-end rot disease in mangoes, and Colletotrichum gloeosporioides, the causal agent of anthracnose disease in mangoes, was determined during culture at 30 degrees C and at several pH values (4.5, 5.5, and 6.5). When the results of using the LPS were compared with those from control cultures without the LPS reagents, the growth of the three microorganisms was totally inhibited in all of the conditions tested. Viability tests enumerating cultivable cells of X. campestris showed that the LPS had a bactericidal effect, whatever the pH value. This effect is faster at pH 5.5, corroborating the results reported in the literature (optimal pH for the LPS efficiency). Further, we proved that hydrogen peroxide alone had little inhibition effect on the growth of the microorganisms studied. This compound is essentially used to convert thiocyanate into hypothiocyanate during the lactoperoxidase reaction. The potential of the LPS for the postharvest treatment of the fruits for controlling microbial diseases was thus demonstrated. Nevertheless, further studies are needed on fresh fruits before envisaging any application. PMID:16013395

  4. Control of Ralstonia Solanacearum The Causal Agent of Brown Rot in Potato Using Essential Oils

    International Nuclear Information System (INIS)

    Five essential oils, namely peppermint (Mentha piperita L.), caraway (Carium carvum L.), fennel (Foeniculum vulgare Mill.), lemongrass (Cymbopogon citratus Staph.) and thyme (Thymus vulgaris), were used separately against Ralstonia solanacearum; the causal agent of brown rot in potato. The most two effective oils (peppermint and thyme) were used in vitro and in vivo after testing their effects on potato tubers buds germination. Peppermint inhibited buds germination but thyme have no effects on buds germination. In vivo, the control of brown rot using thyme oil in glass house experiment reduced the percentage of brown rot infection to 30.6% and reduced the severity of disease from 5 to 3.

  5. Survival of Fusarium graminearum, the causal agent of Fusarium head blight. A review

    OpenAIRE

    Leplat, Johann; Friberg, Hanna; Abid, Muhammad; Steinberg, Christian

    2013-01-01

    Wheat is one of the most cultivated crops worldwide. In 2010, 20 % of wheat and durum wheat were cultivated in Europe, 17 % in China and 9 % in Russia and in North America. Wheat yield can be highly decreased by several factors. In particular Fusarium graminearum Schwabe is a worldwide fungal pest impacting wheat production. F. graminearum is the causal agent of Fusarium head blight, root and stem-base rot of cereals. Losses caused by Fusarium head blight in Northern and Central America from ...

  6. Molecular Detection of Monilinia fructigena as Causal Agent of Brown Rot on Quince

    Directory of Open Access Journals (Sweden)

    Jovana Hrustić

    2012-01-01

    Full Text Available Species of the genus Monilinia are important causal agents of fruit rot on pome and stone fruits in Serbia. The pathogen is very harmful, especially on small properties and cottage plantations where intensive control measures are not applied. Quince is importanthost for the pathogens of this genus. During spring 2010, intensive occurrence of mummified fruits overwintering on branches of the quince was observed. The pathogen was isolated using standard phytopathological methods. Pathogenicity of eight obtained isolates was tested by artificial inoculation of injured apple fruits. Identification was performed according to pathogenic, morphological and ecological properties, and was confirmed by Multiplex polimeraze chain reaction, PCR. All the isolates studied caused brown rot on inoculated apple fruits. The isolates form light yellow colonies with lobate margins,with single-celled, transparent, elliptical or oval conidia in chains, regardless temperature or light presence. Sclerotia are observed in 14 days old cultures. The highest growth rate of most of the isolates is at 27°C and in dark. Based on studied pathogenic, morphological and ecological characteristics, it was found that the Monilinia fructigena is causal agent of brown rot of quince. Using specific primers (MO368-5, MO368-8R, MO368-10R, Laxa-R2for detection of Monilinia species in Multiplex PCR reaction, the expected fragment 402 bp in size was amplified, which confirmed that the studied isolates belonged to the speciesM. fructigena.

  7. 'Candidatus Liberibacter asiaticus', Causal Agent of Citrus Huanglongbing, Is Reduced by Treatment with Brassinosteroids.

    Science.gov (United States)

    Canales, Eduardo; Coll, Yamilet; Hernández, Ingrid; Portieles, Roxana; Rodríguez García, Mayra; López, Yunior; Aranguren, Miguel; Alonso, Eugenio; Delgado, Roger; Luis, Maritza; Batista, Lochy; Paredes, Camilo; Rodríguez, Meilyn; Pujol, Merardo; Ochagavia, María Elena; Falcón, Viviana; Terauchi, Ryohei; Matsumura, Hideo; Ayra-Pardo, Camilo; Llauger, Raixa; Pérez, María del Carmen; Núñez, Mirian; Borrusch, Melissa S; Walton, Jonathan D; Silva, Yussuan; Pimentel, Eulogio; Borroto, Carlos; Borrás-Hidalgo, Orlando

    2016-01-01

    Huanglongbing (HLB) constitutes the most destructive disease of citrus worldwide, yet no established efficient management measures exist for it. Brassinosteroids, a family of plant steroidal compounds, are essential for plant growth, development and stress tolerance. As a possible control strategy for HLB, epibrassinolide was applied to as a foliar spray to citrus plants infected with the causal agent of HLB, 'Candidatus Liberibacter asiaticus'. The bacterial titers were reduced after treatment with epibrassinolide under both greenhouse and field conditions but were stronger in the greenhouse. Known defense genes were induced in leaves by epibrassinolide. With the SuperSAGE technology combined with next generation sequencing, induction of genes known to be associated with defense response to bacteria and hormone transduction pathways were identified. The results demonstrate that epibrassinolide may provide a useful tool for the management of HLB. PMID:26731660

  8. 'Candidatus Liberibacter asiaticus', Causal Agent of Citrus Huanglongbing, Is Reduced by Treatment with Brassinosteroids.

    Directory of Open Access Journals (Sweden)

    Eduardo Canales

    Full Text Available Huanglongbing (HLB constitutes the most destructive disease of citrus worldwide, yet no established efficient management measures exist for it. Brassinosteroids, a family of plant steroidal compounds, are essential for plant growth, development and stress tolerance. As a possible control strategy for HLB, epibrassinolide was applied to as a foliar spray to citrus plants infected with the causal agent of HLB, 'Candidatus Liberibacter asiaticus'. The bacterial titers were reduced after treatment with epibrassinolide under both greenhouse and field conditions but were stronger in the greenhouse. Known defense genes were induced in leaves by epibrassinolide. With the SuperSAGE technology combined with next generation sequencing, induction of genes known to be associated with defense response to bacteria and hormone transduction pathways were identified. The results demonstrate that epibrassinolide may provide a useful tool for the management of HLB.

  9. Identification and Control of Cladobotryum spp., Causal Agents of Cobeweb Disease of Cultivated Mushroom

    Directory of Open Access Journals (Sweden)

    Ivana Potočnik

    2009-01-01

    Full Text Available Cladobotryum spp. are causal agents of cobweb disease, one of the most serious diseases of cultivated mushroom (Agaricus bisporus (Lange Imbach in Serbia and worldwide, which affects product quality and yield. The disease symptoms are: cottony fluffy white oryellowish to pink colonies on mushroom casing, rapid colonization of casing surface, covering of host basidiomata by mycelia, and their decay. Prochloraz-Mn has been officially recommended for mushroom cultivation in EU countries. However, inefficiency of prochloraz-Mn has been noted at a level of spotting symptoms of cobweb disease. With regard to cases of resistance evolution and a general threat to the environment and human health, special attention should be focused on good programmes of hygiene, and inventing and developing alternative methods of disease control.

  10. Integrated Management of Causal Agents of Postharvest Fruit Rot of Apple

    Directory of Open Access Journals (Sweden)

    Mila Grahovac

    2011-01-01

    Full Text Available One of the major causes of poor quality and fruit loss (during storage and transportare diseases caused by phytopathogenic fungi. Economic losses which are the consequenceof the phytopathogenic fungus activity after harvest exceed the losses in the field.Themost important postharvest fungal pathogens of apple fruits are: Botrytis cinerea Pers. exFr., Penicillium expansum (Lk. Thom., Cryptosporiopsis curvispora (Peck. Grem., Colletotrichumgloeosporioides (Penz. Sacc., Monilinia sp., Gloeosporium album Osterw, Alternaria alternata(Fr. Keissler, Cladosporium herbarium Link., Cylindrocarpon mali (Alles. Wollenw., Stemphyliumbotryosum Wallr. The use of available protection technologies can significantly reducelosses caused by pathogens in storage. The concept of integrated pest management (IPMin apple fruits i.e. sustainable approach in control of causal agents of postharvest fruit rot,using cultural, physical, biological and chemical measures, to minimize economic, healthand risks to consumers and environment, is presented in the paper.

  11. Role of Amblyomma lepidum in the transmission of Mycobacterium farcinogenes, the causal agent of Bovine farcy

    Directory of Open Access Journals (Sweden)

    Eltayib Badowi Hasabelrasoul

    2015-06-01

    Full Text Available The present study was conducted to investigate the role of Amblyomma lepidum in the transmission of Mycobacterium farcinogenes, the causal agent of bovine farcy in Sudan. A total of 22 samples comprising of prescapular, submaxillary, mediastinal, parotid, retropharengeal and pulmonary lymph nodes, and subcutaneous nodules were collected for this study. M. farcinogenes was successfully isolated from the specimens by following traditional bacteriological techniques, and the bacteria were identified using standard biochemical assays, lipid analysis using Thin Layer Chromatography, and duplex Polymerase Chain Reaction. Larvae and nymphs of A. lepidum acquired M. farcinogenes from experimentally infected rabbits, and subsequently transmitted the infection to fresh rabbits within a maximum period of ten weeks. In contrast, adult A. lepidum failed to contract the organism from the infected rabbits; so, trans-ovarian transmission could be ruled out. In conclusion, this study confirmed the trans-stadial transmission of M. farcinogenes through larvae and nymphs of A. lepidum.

  12. ‘Candidatus Liberibacter asiaticus’, Causal Agent of Citrus Huanglongbing, Is Reduced by Treatment with Brassinosteroids

    Science.gov (United States)

    Hernández, Ingrid; Portieles, Roxana; Rodríguez García, Mayra; López, Yunior; Aranguren, Miguel; Alonso, Eugenio; Delgado, Roger; Luis, Maritza; Batista, Lochy; Paredes, Camilo; Rodríguez, Meilyn; Pujol, Merardo; Ochagavia, María Elena; Falcón, Viviana; Terauchi, Ryohei; Matsumura, Hideo; Ayra-Pardo, Camilo; Llauger, Raixa; Pérez, María del Carmen; Núñez, Mirian; Borrusch, Melissa S.; Walton, Jonathan D.; Silva, Yussuan; Pimentel, Eulogio; Borroto, Carlos; Borrás-Hidalgo, Orlando

    2016-01-01

    Huanglongbing (HLB) constitutes the most destructive disease of citrus worldwide, yet no established efficient management measures exist for it. Brassinosteroids, a family of plant steroidal compounds, are essential for plant growth, development and stress tolerance. As a possible control strategy for HLB, epibrassinolide was applied to as a foliar spray to citrus plants infected with the causal agent of HLB, ‘Candidatus Liberibacter asiaticus’. The bacterial titers were reduced after treatment with epibrassinolide under both greenhouse and field conditions but were stronger in the greenhouse. Known defense genes were induced in leaves by epibrassinolide. With the SuperSAGE technology combined with next generation sequencing, induction of genes known to be associated with defense response to bacteria and hormone transduction pathways were identified. The results demonstrate that epibrassinolide may provide a useful tool for the management of HLB. PMID:26731660

  13. Candiduria nosocomial: etiología y prevalencia de sus agentes causales en el Hospital Paroissien

    Directory of Open Access Journals (Sweden)

    Liliana Silvia Mónaco

    2010-12-01

    Full Text Available Se evaluó retrospectivamente la etiología y evolución de la frecuencia de los agentes causales de candiduria, en 300 episodios ocurridos en pacientes internados en el Hospital Paroissien, entre el 21 de enero de 2000 y el 30 de diciembre de 2009. Fueron diagnosticados 33 (11,0% episodios en 2000, 26 (8,7% en 2001, 34 (11,3% en 2002, 20 (6,7% en 2003, 30 (10,0% en 2004, 25 (8,3% en 2005, 47 (15,7% en 2006, 27 (9,0% en 2007, 33 (11,0% en 2008 y 25 (8,3% en 2009. Candida tropicalis, C. albicans, C. glabrata y C. parapsilosis prevalecieron en orden descendente de frecuencia y C. guillermondii, C. krusei y C. lusitaniae se aislaron excepcionalmente. C. tropicalis prevaleció entre 2000-2002, 2004-2006 y en 2008, seguida por C. albicans, que fue la más prevalente en 2003, 2007 y 2009. C. glabrata ocupó el segundo lugar en 2000, 2004 y 2006 y el tercero en los demás años, salvo en 2001, 2008 y 2009, cuando fue desplazada por C. parapsilosis, que en 2009 ocupó el primer lugar junto con C. albicans. Los resultados obtenidos confirman el predominio de las especies de Candida no- albicans como agentes causales de candiduria en la población estudiada, particularmente C. tropicalis, desde 2003, que podría mantenerse actualmente. La ausencia de datos previos impidió discernir si los patrones hallados son recientes o se mantuvieron a través del tiempo.

  14. Modelo causal dos primórdios da ciência do magnetismo

    Directory of Open Access Journals (Sweden)

    Osvaldo Pessoa Júnior

    2010-06-01

    Full Text Available Este artigo apresenta uma breve história do nascimento da ciência do magnetismo, que ocorreu em três continentes distintos de maneira independente. Aplica-se a metodologia dos modelos causais em história da ciência para representar esses caminhos independentes, onde aparece a noção de "gargalo de desenvolvimento". Ênfase é dada para a definição de "avanços generalizados", que reúnem diferentes espécies de avanços e simplicam os diagramas causais. O relato histórico enfoca os avanços na China e na Europa até 1600.This article presents a brief history of the beginning of the science of magnetism, which took place independently in three different continents. The methodology of causal models in the history of science is applied to represent these independent paths, where the notion of "developmental bottleneck" appears. Special attention is given to the definition of "generalized advances", which encompass different species of advances and simplify the causal diagrams. The historical survey covers the advances in magnetism in China and Europe until 1600.

  15. Killer yeasts inhibit the growth of the phytopathogen Moniliophthora perniciosa, the causal agent of Witches' Broom disease Leveduras micocinogênicas inibem o crescimento do fitopatógeno Moniliophthora perniciosa, o agente causador da doença Vassoura-de-bruxa

    Directory of Open Access Journals (Sweden)

    Anderson de Souza Cabral

    2009-03-01

    Full Text Available Fruit and soil yeasts isolated from the Amazon, Atlantic Rainforests and an organic farm were screened for killer activity against yeasts. Killer yeasts were then tested against the phytopathogen Moniliophthora perniciosa (syn. Crinipellis perniciosa and a Dipodascus capitatus strain and a Candida sp strain inhibited its growth.Leveduras de frutas e de solo isoladas da Floresta Amazônica, Mata Atlântica e de uma fazenda orgânica foram selecionadas em uma triagem para atividade micocinogênica. As estirpes micocinogênicas foram posteriormente testadas frente a Moniliophthora perniciosa (syn. Crinipellis perniciosa. Uma estirpe de Dipodascus capitatus e outra de Candida sp.inibiram o crescimento deste fitopatógeno.

  16. White rot of garlic and onion (Causal agent, Sclerotium cepivorum): A status report from the Pacific Northwest

    Science.gov (United States)

    There is evidence from literature, state department of agriculture documents, and recent diagnoses that Sclerotium cepivorum, causal agent of white rot of garlic and onion, is spreading and/or becoming more established in the Pacific Northwest. Previously documented distributions are summarized, an...

  17. Characterization of single-nucleotide-polymorphism markers for Plasmopara viticola, the causal agent of grapevine downy mildew.

    Science.gov (United States)

    Delmotte, F; Machefer, V; Giresse, X; Richard-Cervera, S; Latorse, M P; Beffa, R

    2011-11-01

    We report 34 new nuclear single-nucleotide-polymorphism (SNP) markers that have been developed from an expressed sequence tag library of Plasmopara viticola, the causal agent of grapevine downy mildew. This newly developed battery of markers will provide useful additional genetic tools for population genetic studies of this important agronomic species. PMID:21926208

  18. Microsatellite markers for characterization of native and introduced populations of Plasmopara viticola, the causal agent of grapevine downy mildew.

    Science.gov (United States)

    Rouxel, Mélanie; Papura, Daciana; Nogueira, Marilise; Machefer, Virginie; Dezette, Damien; Richard-Cervera, Sylvie; Carrere, Sébastien; Mestre, Pere; Delmotte, François

    2012-09-01

    We reported 31 microsatellite markers that have been developed from microsatellite-enriched and direct shotgun pyrosequencing libraries of Plasmopara viticola, the causal agent of grapevine downy mildew. These markers were optimized for population genetics applications and used to characterize 96 P. viticola isolates from three European and three North American populations. PMID:22706046

  19. A gênese da causalidade física The genesis of physical causality

    Directory of Open Access Journals (Sweden)

    Michel Paty

    2004-03-01

    Full Text Available As noções ou categorias de causalidade e determinismo acompanharam a formação das ciências modernas e, em primeiro lugar, da física. O uso corrente em nossos dias tende freqüente e erroneamente a confundi-las, nas reconsiderações feitas pela própria física. Propomo-nos esclarecer aqui a primeira dessas noções, mais precisamente a de causalidade física, examinando sua elaboração no início da dinâmica, por meio das primeiras operações e conceituações que acompanham a matematização da mecânica, antes dela ser estendida à física em geral. Veremos como, apoiando-se inteiramente em um aspecto filosófico tradicional da idéia de causalidade (aquele de "causa eficiente", a causalidade física se estabelece em ruptura com o sentido metafísico que lhe era anteriormente associado. Mais do que no Principia de Newton, é na reelaboração por d'Alembert, no Traité de dynamique, das leis do movimento formuladas como princípios e expressas pelo cálculo diferencial, que a idéia de causalidade física é expressamente considerada como indissociável de seu efeito, que é a mudança de movimento. Os respectivos pensamentos de Newton e de d'Alembert sobre as noções de causa e de força estão a esse propósito em oposição, diferindo quanto à natureza propriamente física dessa mudança, considerada por d'Alembert como imanente ao movimento, segundo a causa circunscrita por seu efeito, enquanto ela permanece matemática e metafísica na concepção newtoniana da força externa, como substituto matemático das causas, tal como havia sido proposto antes da mecânica analítica de Lagrange. Foi a concepção física herdada de d'Alembert, que prevaleceria a seguir por meio da mecânica analítica lagrangiana, que permitiu reintegrar física e racionalmente o conceito de força em sua transcrição diferencial euleriana.The notions or categories of causality and determinism have accompanied the formation of modern sciences, and

  20. Tetranychus urticae (Acari: Tetranychidae) transmits Acidovorax citrulli, causal agent of bacterial fruit blotch of watermelon.

    Science.gov (United States)

    Choi, Okhee; Park, Jung-Joon; Kim, Jinwoo

    2016-08-01

    The two-spotted spider mite (TSSM) Tetranychus urticae is one of the most important pests of cucurbit plants. If TSSM can act as vector for Acidovorax citrulli (Acc), causal agent of bacterial fruit blotch (BFB), then the movement of mites from infected to healthy plants may represent a potential source of inocula for BFB outbreaks. To confirm the association between Acc and TSSM, we generated a green fluorescent protein-tagged mutant strain (Acc02rf) by transposon mutagenesis and demonstrated that TSSM can transmit Acc from infected to non-infected watermelon plants. Challenge with 10 TSSMs carrying Acc02rf population densities of 1.3 × 10(3) CFU each on freshly grown individual watermelon plants caused disease transmission to 53 %. Incubation periods ranged 7-9 days. Bacteria recovered from symptoms typical of those associated with leaf necrosis were characterized and identified as Acc. To our knowledge, this is the first report showing that TSSM can be a vector of Acc. The results reported here support that the strong association of TSSM with Acc is of particular importance in controlling BFB. PMID:27178042

  1. Erwinia amylovora – the Causal Agent of Root Collar Necrosis of Apple Trees

    Directory of Open Access Journals (Sweden)

    Veljko Gavrilović

    2008-01-01

    Full Text Available A large-scale outbreak of fire blight symptoms caused by Erwinia amylovora was recorded in pome fruit trees during 2007. In addition to fruit necrosis and shoot blight as the typical disease symptoms, dark purple necrosis was observed in the root collar area girdling the trunk just above the ground and thus withering the whole apple tree. Since similar symptoms on apple trees could be caused by E. amylovora or one of several phytopathogenic fungi of the genera Phomopsis and Phytophthora, an investigation was conducted to identify the causal agent of this disease. Levan-producing, nonfluorescent bacteria were isolated from diseased samples. The isolated strains produced HR in tobacco leaves and necrosis of artificially inoculated, immature pear fruits, followed by oozing of bacterial exudate, a characterisitic of E. amylovora. Based on the results of pathogenicity tests, biochemical characteristics, ELISA test and PCR analysis, it was confirmed that the investigated strainsbelonged to E. amylovora, causing the root collar necrosis of apple trees as an atypical symptom of this bacterium in Serbia. The explanation of this symptom may be that the vegetative rootstocks were infected with E. amylovora. Therefore, the development of diagnostic protocols for detection of E. amylovora in apple rootstock is very important for health inspections of planting materials.

  2. Microsatellite isolation and characterization for Colletotrichum spp, causal agent of anthracnose in Andean blackberry.

    Science.gov (United States)

    Marulanda, M L; López, A M; Isaza, L; López, P

    2014-01-01

    The genus Colletotrichum, comprised of pathogenic fungi that affect plants grown worldwide, causes the disease known as anthracnose in several fruit and vegetable species. Several studies conducted on plants have shown that the disease is characterized by the presence of one or several species of the fungus attacking the fruit or other organs of the same host. To develop and implement effective control strategies, it is vital to understand the genetic structure of the fungus in agricultural systems, identify associated Colletotrichum species, and define the subpopulations responsible for the disease. Molecular tools were accordingly developed to characterize genotypic populations of Colletotrichum spp, causal agent of anthracnose in commercial crops of Andean blackberry (Rubus glaucus Benth.). A microsatellite-enriched library for Colletotrichum gloeosporioides was developed to identify and characterize microsatellite loci among isolates collected in R. glaucus plantations. Thirty microsatellites were developed and tested in 36 isolates gathered from eight different blackberry-production areas of Colombia. Ten pairs of microsatellites were polymorphic. PMID:25299081

  3. Morphological and molecular characterization of the causal agent of downy mildew on Quinoa (Chenopodium quinoa).

    Science.gov (United States)

    Choi, Young-Joon; Danielsen, Solveig; Lübeck, Mette; Hong, Seung-Beom; Delhey, Rolf; Shin, Hyeon-Dong

    2010-05-01

    Downy mildew is an economically important and widespread disease in quinoa (Chenopodium quinoa) growing areas. Although in many studies Peronospora farinosa is most commonly regarded as the causal agent of the disease, identification and classification of the pathogen remain still uncertain due to its taxonomic confusion. Thirty-six Peronospora isolates from quinoa with different geographic origins including Argentina, Bolivia, Denmark, Ecuador, and Peru were morphologically and molecularly compared with Peronospora species from other Chenopodium species. The morphology of three herbarium specimens was similar to that of P. variabilis, which originated from C. album, characterized by flexuous to curved ultimate branchlets and pedicellated conidia. Phylogenetic analysis based on ITS rDNA sequences also placed the quinoa pathogen within the same clade as P. variabilis. Within the ITS rDNA sequences of the quinoa pathogens, two base substitutions were found, which separated the majority of the Danish isolates from isolates from South America, but no sequence difference was found among the isolates from different cultivars of quinoa. The present results indicate that the pathogen responsible for the quinoa downy mildew is identical to Peronospora variabilis and that it should not be lumped with P. farinosa as claimed previously by most studies. PMID:20101524

  4. Potential of Pest and Host Phenological Data in the Attribution of Regional Forest Disturbance Detection Maps According to Causal Agent

    Science.gov (United States)

    Spruce, Joseph; Hargrove, William; Norman Steve; Christie, William

    2014-01-01

    Near real time forest disturbance detection maps from MODIS NDVI phenology data have been produced since 2010 for the conterminous U.S., as part of the on-line ForWarn national forest threat early warning system. The latter has been used by the forest health community to identify and track many regional forest disturbances caused by multiple biotic and abiotic damage agents. Attribution of causal agents for detected disturbances has been a goal since project initiation in 2006. Combined with detailed cover type maps, geospatial pest phenology data offer a potential means for narrowing the candidate causal agents responsible for a given biotic disturbance. U.S. Aerial Detection Surveys (ADS) employ such phenology data. Historic ADS products provide general locational data on recent insect-induced forest type specific disturbances that may help in determining candidate causal agents for MODIS-based disturbance maps, especially when combined with other historic geospatial disturbance data (e.g., wildfire burn scars and drought maps). Historic ADS disturbance detection polygons can show severe and extensive regional forest disturbances, though they also can show polygons with sparsely scattered or infrequent disturbances. Examples will be discussed that use various historic disturbance data to help determine potential causes of MODIS-detected regional forest disturbance anomalies.

  5. Biocontrol of Rhizoctonia solani, the causal agent of bean damping-off by fluorescent pseudomonads.

    Science.gov (United States)

    Afsharmanesh, H; Ahmadzadeh, M; Sharifi-Tehrani, A

    2006-01-01

    Rhizosphere bacteria belonging to the fluorescent pseudomonads are receiving increasing attention for the protection of plants against soil-borne fungal pathogens. Among these pathogens, Rhizoctonia solani, the causal agent of bean damping- off is very important in bean fields of Iran. In this study, the antagonistic activity of 46 isolates of fluorescent pseudomonads (isolated from different area of Iran) and Pseudomonas fluorescens strain CHA0 investigated against one isolate of R. solani. About 64% of isolates revealed antagonistic activity against R. solani. Production of antifungal metabolites such as HCN, siderophore and protease was evaluated. The results showed that 97.8%, 17% and 78% of isolates produced siderophore, HCN and protease respectively. There was no significant correlation between antagonistic activity and production of these metabolites. Isolates P-5, P-10 and P-32 with strain CHA0 were selected in order to investigate involvement of siderophore, volatile metabolites (HCN), and non-volatile metabolites in reducing mycelial growth of R. olani. Isolate P-5 showed much more inhibitory effect by production of volatile metabolites and siderophore. Non-volatile metabolites in isolates P-32 and P-5 completely inhibited mycelial growth of the fungus. After the primary labrotory tests, isolates P-14, P-35, P-30, P-5 and strain CHA0 were selected for in vivo experiments. These selected isolates with benomyl fungicide were used as seed coating and soil drenching in sterile soil under greenhouse condition. The result indicated that in seed treatment method, isolates P-30 by 66% had the most effect in disease reduction while in soil treatment method, strain CHAO by 60% had the most effect, such that this two isolates showed significant differences in comparison with plants inoculated with R. solani inoculums. PMID:17390854

  6. Monitoring of Soft Fruit Mother Plantings Aimed at Control of Phytophthora fragariae, Causal Agent of Root Rot

    OpenAIRE

    Slobodan Milenković; Dušica Sretenović

    2007-01-01

    Phytophthora fragariae was first detected in the Republic of Serbia in 2002, and it has been included in A2 quarantine list of damaging organisms since 2003. The project titled ‘Monitoring of soft fruit mother plantings aimed at the control of Phytophthora fragariae, causal agent of root rot’ was realized over 2004 – 2005 aiming at determination of population rate of the pathogen and the control of raspberry planting material. Over that period, the total 388 samples were tested. Collected sam...

  7. Monitoring of Soft Fruit Mother Plantings Aimed at Control of Phytophthora fragariae, Causal Agent of Root Rot

    OpenAIRE

    Slobodan Milenković; Dušica Sretenović

    2006-01-01

    Phytophthora fragariae was first detected in the Republic of Serbia in 2002, and it has been included in A2 quarantine list of damaging organisms since 2003. The project titled ‘Monitoring of soft fruit mother plantings aimed at the control of Phytophthora fragariae, causal agent of root rot’ was realized over 2004 – 2005 aiming at determination of population rate of the pathogen and the control of raspberry planting material. Over that period, the total 388 samples were tested. Collected sam...

  8. Identificación del agente causal de la pudrición blanca en morelos, méxico

    OpenAIRE

    2013-01-01

    Título en ingles: Identification of the white rot agent in Morelos, Mexico Título corto: Agente causal de la pudrición blanca en Morelos, México Resumen: Cepas aisladas de Trametes versicolor (L.:Fr.) Pilát causando pudrición blanca en especies arbóreas de amate amarillo (Ficus petiolaris), cirián o cuatecomate (Crescentia alata), guayaba (Psidium guajava) y sauce colorado (Salix humboltiana) en los municipios de Ayala, Cuautla, Cuernavaca, Jojutla, Tepalcingo, Tlaltizapán, Tlaquiltenango y Z...

  9. Murcha do manjericão (Ocimum basilicum no Brasil: agente causal, círculo de plantas hospedeiras e transmissão via semente Sweet basil (Ocimum basilicum wilt in Brazil: causal agent, host range and seed transmission

    Directory of Open Access Journals (Sweden)

    Ailton Reis

    2007-06-01

    Full Text Available O manjericão (Ocimum basilicum L. é uma hortaliça da família Lamiaceae, utilizada na culinária ou como matéria prima para a indústria de fármacos e óleos essenciais. Amostras de plantas de manjericão apresentando sintomas de murcha, seca de hastes e podridão de colo foram coletadas na área rural de Brazlândia (DF durante a estação chuvosa de 2005. Outras duas amostras foram coletadas em plantas cultivadas em campo aberto e casas de vegetação na região de Ponte Alta (DF. Isolados de um fungo, identificado como Fusarium oxysporum, foram obtidos em todas as amostras. Testes de patogenicidade foram conduzidos com mudas das cultivares O. basilicum 'Dark Opal' e 'Italian Large Leaf', e de acessos das espécies O. americanum L. (manjericão de folha miúda, O. campechianum Mill. (alfavaca, Origanum manjorana L. (manjerona, Origanum vulgare L. (orégano, Mentha arvensis L. (menta, Coleus blumei Benth. (tapete, Leonorus sibiricus L. (rubim e Leonotis nepetaefolia (L. W.T. Aiton (cordão-de-frade. Todos os isolados fúngicos mostraram-se altamente virulentos sobre as duas cultivares de manjericão. Em O. campechianum e O. americanum os isolados causaram apenas suave escurecimento vascular e leve redução de crescimento, sendo avirulentos sobre acessos das espécies O. manjorana, O. vulgare, M. arvensis, C. blumei, L. sibiricus e L. nepetaefolia. Este conjunto de dados indicou que o agente causal da doença é o fungo F. oxysporum f. sp. basilici, constituindo-se no primeiro registro formal deste patógeno no Brasil. Os lotes de sementes utilizados nas áreas de ocorrência da doença foram submetidos a um teste de sanidade visando verificar a presença do patógeno. O fungo F. oxysporum f. sp. basilici foi detectado em quatro dos seis lotes e os isolados obtidos das sementes contaminadas mostraram similar sintomatologia e um idêntico perfil de virulência aos verificados em campo e casa de vegetação, sugerindo que as sementes

  10. Clarification on Host Range of Didymella pinodes the Causal Agent of Pea Ascochyta Blight.

    Science.gov (United States)

    Barilli, Eleonora; Cobos, Maria José; Rubiales, Diego

    2016-01-01

    Didymella pinodes is the principal causal agent of ascochyta blight, one of the most important fungal diseases of pea (Pisum sativum) worldwide. Understanding its host specificity has crucial implications in epidemiology and management; however, this has not been clearly delineated yet. In this study we attempt to clarify the host range of D. pinodes and to compare it with that of other close Didymella spp. D. pinodes was very virulent on pea accessions, although differences in virulence were identified among isolates. On the contrary, studied isolates of D. fabae, D. rabiei, and D. lentil showed a reduced ability to infect pea not causing macroscopically visible symptoms on any of the pea accessions tested. D. pinodes isolates were also infective to some extend on almost all species tested including species such as Hedysarum coronarium, Lathyrus sativus, Lupinus albus, Medicago spp., Trifolium spp., Trigonella foenum-graecum, and Vicia articulata which were not mentioned before as hosts of D. pinodes. On the contrary, D. lentil and D. rabiei were more specific, infecting only lentil and chickpea, respectively. D. fabae was intermediate, infecting mainly faba bean, but also slightly other species such as Glycine max, Phaseolus vulgaris, Trifolium spp., Vicia sativa, and V. articulata. DNA sequence analysis of the nuclear ribosomal internal transcribed spacer region (ITS) was performed to confirm identity of the isolates studies and to determine phylogenetic relationship among the Didymella species, revealing the presence of two clearly distinct clades. Clade one was represented by two supported subclusters including D. fabae isolates as well as D. rabiei with D. lentil isolates. Clade two was the largest and included all the D. pinodes isolates as well as Phoma medicaginis var. pinodella. Genetic distance between D. pinodes and the other Didymella spp. isolates was not correlated with overall differences in pathogenicity. Based on evidences presented here, D

  11. ANTAGONISTIC EFFECT OF FOUR FUNGAL ISOLATES TO GANODERMA BONINENSE, THE CAUSAL AGENT OF BASAL STEM ROT OF OIL PALM

    Directory of Open Access Journals (Sweden)

    OKKY SETYAWATI DHARMAPUTRA

    1990-01-01

    Full Text Available Four fungal isolates from soils obtained from three sites of the oil palm plantations in North Sumatra were found antagonistic to Ganoderma boninense, the causal agent of basal stem rot of oil palm. Penicillium citrinum inhibited the growth of the pathogen and formed a zone of inhibition on the agar media. Trichoderma harzianum BIO - 1 as well as BIO - 2 and T. viride not only repressed the growth of the pathogen but also caused lysis of the hyphae, and the colony was totally overgrown by the antagonists.

  12. Monitoring of Soft Fruit Mother Plantings Aimed at Control of Phytophthora fragariae, Causal Agent of Root Rot

    Directory of Open Access Journals (Sweden)

    Slobodan Milenković

    2006-12-01

    Full Text Available Phytophthora fragariae was first detected in the Republic of Serbia in 2002, and it has been included in A2 quarantine list of damaging organisms since 2003. The project titled ‘Monitoring of soft fruit mother plantings aimed at the control of Phytophthora fragariae, causal agent of root rot’ was realized over 2004 – 2005 aiming at determination of population rate of the pathogen and the control of raspberry planting material. Over that period, the total 388 samples were tested. Collected samples were analyzed by PCR. The presence of Phytophthora fragariae was detected in 156 samples.

  13. Monitoring of Soft Fruit Mother Plantings Aimed at Control of Phytophthora fragariae, Causal Agent of Root Rot

    Directory of Open Access Journals (Sweden)

    Slobodan Milenković

    2006-01-01

    Full Text Available Phytophthora fragariae was first detected in the Republic of Serbia in 2002, and it has been included in A2 quarantine list of damaging organisms since 2003. The project titled ‘Monitoring of soft fruit mother plantings aimed at the control of Phytophthora fragariae, causal agent of root rot’ was realized over 2004 – 2005 aiming at determination of population rate of the pathogen and the control of raspberry planting material. Over that period, the total 388 samples were tested. Collected samples were analyzed by PCR. The presence of Phytophthora fragariae was detected in 156 samples.

  14. Characterization of Mycobacterium salmoniphilum as causal agent of mycobacteriosis in Atlantic salmon, Salmo salar L., from a freshwater recirculation system.

    Science.gov (United States)

    Aro, L; Correa, K; Martínez, A; Ildefonso, R; Yáñez, J M

    2014-04-01

    Thirty Atlantic salmon, Salmo salar L., with low corporal condition relative to other fish present in the culture system, were sampled from a freshwater recirculation pisciculture located in Chile. The most characteristic signs and lesions were cachexia and presence of multiple greyish-white granulomas within internal organs. The external and internal lesions, along with the microscopic, histologic and biochemical findings, were consistent with mycobacteriosis. The identification of Mycobacterium salmoniphilum as the causal agent of the lesions was possible through the use of molecular analyses. This study represents the first report of Mycobacterium salmoniphilum in a freshwater recirculation system and the first case of fish mycobacteriosis described in Chile. PMID:23952471

  15. Species-specific detection and identification of fusarium species complex, the causal agent of sugarcane pokkah boeng in China.

    Directory of Open Access Journals (Sweden)

    Zhenyue Lin

    Full Text Available BACKGROUND: Pokkah boeng disease caused by the Fusarium species complex results in significant yield losses in sugarcane. Thus, the rapid and accurate detection and identification of the pathogen is urgently required to manage and prevent the spreading of sugarcane pokkah boeng. METHODS: A total of 101 isolates were recovered from the pokkah boeng samples collected from five major sugarcane production areas in China throughout 2012 and 2013. The causal pathogen was identified by morphological observation, pathogenicity test, and phylogenetic analysis based on the fungus-conserved rDNA-ITS. Species-specific TaqMan real-time PCR and conventional PCR methods were developed for rapid and accurate detection of the causal agent of sugarcane pokkah boeng. The specificity and sensitivity of PCR assay were also evaluated on a total of 84 isolates of Fusarium from China and several isolates from other fungal pathogens of Sporisorium scitamineum and Phoma sp. and sugarcane endophyte of Acremonium sp. RESULT: Two Fusarium species (F. verticillioides and F. proliferatum that caused sugarcane pokahh boeng were identified by morphological observation, pathogenicity test, and phylogenetic analysis. Species-specific TaqMan PCR and conventional PCR were designed and optimized to target their rDNA-ITS regions. The sensitivity of the TaqMan PCR was approximately 10 pg of fungal DNA input, which was 1,000-fold over conventional PCR, and successfully detected pokkah boeng in the field-grown sugarcane. CONCLUSIONS/SIGNIFICANCE: This study was the first to identify two species, F. verticillioides and F. proliferatum, that were causal pathogens of sugarcane pokkah boeng in China. It also described the development of a species-specific PCR assay to detect and confirm these pathogens in sugarcane plants from mainland China. This method will be very useful for a broad range of research endeavors as well as the regulatory response and management of sugarcane pokkah boeng.

  16. Heterothallism in Peronospora farinosa f.sp. chenopodii, the causal agent of downy mildew of quinoa (Chenopodium quinoa).

    Science.gov (United States)

    Danielsen, S

    2001-01-01

    Heterothallism in Peronospora farinosa f.sp. chenopodii, the causal agent of downy mildew of quinoa (Chenopodium quinoa) is reported for the first time. Downy mildew is the most important disease of this crop in the Andean region. Eight single-lesion isolates from different regions in Peru and Bolivia were crossed in all possible combinations using a detached leaf assay, to determine the mating system of the downy mildew pathogen. The presence of two mating types, P1 and P2, was revealed showing that P. farinosa f.sp. chenopodii is heterothallic. It is suggested that frequent sexual reproduction is an important evolutionary force in this pathogen in South America. PMID:11688216

  17. Actividad antifúngica del quitosano y aceites esenciales sobre rhizopus stolonifer (ehrenb.:fr.) vuill., agente causal de la pudrición blanda del tomate

    OpenAIRE

    Alejandra María Alvarado Hernández; Laura Leticia Barrera Necha; Ana Niurka Hernández Lauzardo; Miguel Gerardo Velázquez del Valle

    2012-01-01

    Título en ingles: Antifungal activity of chitosan and essential oils on Rhizopus stolonifer (Ehrenb.:Fr.) Vuill causal agent of soft rot of tomato ResumenRhizopus stolonifer es el agente causal de la pudrición blanda, enfermedad poscosecha que ocasiona pérdidas económicas importantes. Se han empleado fungicidas sintéticos como el dicloran para controlar a este microorganismo, sin embargo, se ha demostrado que los fungicidas representan un riesgo para el ambiente y la salud humana. Actualmente...

  18. Avaliação de métodos de inoculação, controle químico e alternativo de Pseudoperonospora cubensis (Berk. e Curt.), agente causal do mildio do pepino (Cucumis sativus L.)

    OpenAIRE

    Caballero Almada, Juana Beatriz

    2012-01-01

    No presente trabalho foram avaliados diferentes métodos de inoculação de Pseudoperonospora cubensis (Berk. e Curt.), agente causal do míldio em pepino (Cucumis sativus L.), e o efeito da aplicação de produtos químicos bem como de produtos alternativos no controle do patógeno. Os experimentos foram realizados no período de março a novembro de 1997, no Laboratório de Fitopatologia e em Casa de Vegetação do Setor de Ciências Agrárias da UFPR, Curitiba. Nos 3 experimentos com delineamento inteira...

  19. First report of Veronaea botryosa as a causal agent of chromomycosis in frogs.

    Science.gov (United States)

    Hosoya, Tsuyoshi; Hanafusa, Yasuko; Kudo, Tomoo; Tamukai, Kenichi; Une, Yumi

    2015-05-01

    A dematiaceous hyphomycete, isolated from frogs, was determined as the possible etiologic agent of a case of systemic chromomycosis this cold-blooded animal. The fungus was identified as Veronaea botryosa on the basis of morphological features observed in histopathological examination and molecular phylogenetic evidence. Although V. botryosa is known to be distributed widely in litter and as a human pathogen, this is the first confirmed report of its involvement in a lethal infection in a cold-blooded animal, including an anuran. PMID:25851263

  20. Brown rot on nuts of Castanea sativa Mill: an emerging disease and its causal agent

    OpenAIRE

    Maresi G; Oliveira Longa CM; Turchetti T

    2013-01-01

    The quality and quantity of nut production are fundamental to the economic viability of chestnut cultivation, yet recent reports indicate that severe damage due to moulds represents a significant problem for growers. We carried out an investigation of the agents of chestnut rot and internal fruit damage in three orchards in Italy. Black and brown rot, as well as insect damage, were found in all the areas examined. Brown rot appeared to be the main cause of damage, affecting 8% to 49% and 2% t...

  1. Brown rot on nuts of Castanea sativa Mill: an emerging disease and its causal agent

    Directory of Open Access Journals (Sweden)

    Maresi G

    2013-07-01

    Full Text Available The quality and quantity of nut production are fundamental to the economic viability of chestnut cultivation, yet recent reports indicate that severe damage due to moulds represents a significant problem for growers. We carried out an investigation of the agents of chestnut rot and internal fruit damage in three orchards in Italy. Black and brown rot, as well as insect damage, were found in all the areas examined. Brown rot appeared to be the main cause of damage, affecting 8% to 49% and 2% to 24% of nuts collected from the ground and from burrs, respectively. With respect to morphology and DNA sequencing analyses, fungal isolates obtained from brown rot were homologous with Gnomoniopsis sp. obtained from Dryocosmus kuriphilus (Yasumatsu galls and with Gnomoniopsis castanea and Gnomoniopsis smithogilvyi described on chestnut in Italy and Australia, respectively. The same fungus was also isolated from the bark of one- and two-years-old healthy shoots at each site, supporting the endophytic behaviour of this rot agent. Brown rot symptoms on nuts associated with Gnomoniopsis sp. corresponded with those previously described by several authors and referred to as Phoma or Phomopsis endogena, suggesting a relationship between these fungi and Gnomoniopsis sp. It is to notice that the escalation of brown rot damage in Italy followed several periods of drought and probably the recent invasion of D. kuriphilus, both stress factors for chestnut trees.

  2. Caracterização morfocultural e infecção cruzada de Colletotrichum gloeosporioides agente causal da antracnose de frutos e hortaliças em pós-colheita / Morfocultural characterization and cross infection Colletotrichum gloeosporioides causes anthracnose in fruits and vegetables post-harvested

    Directory of Open Access Journals (Sweden)

    Lucimar Pereira Bonett

    2010-12-01

    Full Text Available O fungo Colletotrichum gloeosporioides infecta uma grande variedade de plantas em regiões tropicais, subtropicais e temperadas ocasionando consideráveis perdas econômicas em doenças pré e pós-colheita. O objetivo deste trabalho foi caracterizar a morfologia e a infecção cruzada de isolados de Colletotrichum gloeosporioides obtidos de frutos e hortaliças em pós-colheita. Os isolados foram obtidos de lesões de frutos com sintomas de antracnose e cultivados em meio de cultivo BDA, sendo a avaliação do crescimento micelial realizada por meio de duas leituras diárias do diâmetro das colônias pelo período de quatorze dias e a caracterização morfológica das colônias realizada no final deste período. Para a realização do experimento, utilizou-se o delineamento experimental inteiramente casualisado com três repetições por tratamento. Para o experimento da infecção cruzada foram realizados dois ferimentos em frutos sadios nos quais foram depositados blocos de meio de cultura com 6 mm2 contendo os isolados. O delineamento experimental foi em esquema fatorial de 8 x 8, com quatro repetições. As médias de ambos os experimentos foram analisadas por meio do teste de Scott-Knott com 5% de probabilidade. A maioria dos isolados de C. gloeosporioides possuem grande potencial de infecção cruzada, já que foram capazes de causar lesões em frutos de mamão, manga, abacate, chuchu, jiló, pimentão verde e pimenta. Os isolados de frutos de mamão e abacate apresentaram o maior índice de crescimento micelial e os isolados provenientes do chuchu apresentaram o menor. Quanto ao desenvolvimento de lesões, o mamão apresentou-se mais suscetível, com lesões maiores, enquanto que a pimenta cambuci demonstrou-se a mais resistente, apresentando as menores lesões.

  3. Screening bactericidal effect of Pectobacterium carotovorum subsp. carotovorum strains against causal agent of potato soft rot.

    Science.gov (United States)

    Kazemi-Zaromi, Samaneh; Baghaee-Ravari, Sareh; Khodaygan, Pejman; Falahati-Rastegar, Mahrokh

    2016-02-01

    This study focuses on the potential of Pectobacterium carotovorum subsp. carotovorum (Pcc) strains producing bacteriocin as a tool to control potato soft rot disease. Thirty out of 48 purified bacterial strains were characterized as Pcc using specific PCR and phenotypic tests. The pathogenicity and pectate degrading assays were recorded positive for 13 strains. Bacteriocin typing clustered producers into three groups according to their antimicrobial spectra. Majority of the producers except strains of group II showed antibacterial activity toward relative genus and the role of UV or mitomycin C was inductive. In addition, none of the distant genus was sensitive to Pcc bacteriocins except Rhizobium vitis. Molecular detection of four bacteriocins including carotovoricin, carosin S1, S2 and carosin D was performed. Overall, 54.5% of group I, 47.3 and 70% of groups II and III strains carried carotovoricin and four strains harbored gene corresponding to carosin S1. According to our data divers antimicrobial patterns obtained by Pcc strains and existence of new bateriocines could be possible. Moreover, our findings recommended that direct application of P29 or expression of corresponding genes of Pog22 or P21 in a nonpathogenic strain as a biocontrol agent may improve soft rot disease control. PMID:26523939

  4. Rapid discrimination of the causal agents of urinary tract infection using ToF-SIMS with chemometric cluster analysis

    Science.gov (United States)

    Fletcher, John S.; Henderson, Alexander; Jarvis, Roger M.; Lockyer, Nicholas P.; Vickerman, John C.; Goodacre, Royston

    2006-07-01

    Advances in time of flight secondary ion mass spectrometry (ToF-SIMS) have enabled this technique to become a powerful tool for the analysis of biological samples. Such samples are often very complex and as a result full interpretation of the acquired data can be extremely difficult. To simplify the interpretation of these information rich data, the use of chemometric techniques is becoming widespread in the ToF-SIMS community. Here we discuss the application of principal components-discriminant function analysis (PC-DFA) to the separation and classification of a number of bacterial samples that are known to be major causal agents of urinary tract infection. A large data set has been generated using three biological replicates of each isolate and three machine replicates were acquired from each biological replicate. Ordination plots generated using the PC-DFA are presented demonstrating strain level discrimination of the bacteria. The results are discussed in terms of biological differences between certain species and with reference to FT-IR, Raman spectroscopy and pyrolysis mass spectrometric studies of similar samples.

  5. Presencia de Blastocystis Hominis como agente causal de enfermedades gatrointestinales en la comuna 7 (Gaira del Distrito de Santa Marta

    Directory of Open Access Journals (Sweden)

    Sonja Liliana Lozano Socarras

    2013-10-01

    Full Text Available La Blastocystis hominis es un protozoo que causa cuadros diarreicos. Es altamente prevalente en poblaciones que no cuentan con servicios adecuados de higiene, alcantarillado y salud pública. La infección con Blastocystis hominis frecuentemente concomita con otros enteropatógenos de reconocida patogenicidad, además se ha reportado como parásito oportunista en pacientes con VIII SIDA. El objetivo del presente estudio es determinar la presencia de Blastocystis hominis en pacientes de consulta externa con síntomas asociados a enfermedades gastrointestinales, en la comuna 7 del distrito de Santa Marta, Colombia, durante el mes de Enero a Diciembre de 2004. El método de diagnóstico utilizado fue examen coproparasitológico seriado y el número de pacientes analiza-dos fue de 291. Los resultados muestran una alta presencia de Blastocystis hominken pacientes con enfermedad diarreica residentes en Gaira. Un alto porcentaje de la población parasitada (62,6% presento como único agente causal de la enfermedad diarreica al Blastocystis hominis lo que sugiere la presencia de otras enfermedades que pueden involucrar un compromiso inmunológico, el efecto será una respuesta inmune débil contra el parásito.

  6. Podredumbres basales de Gypsophila paniculata (Caryophyllaceae: Agentes causales y su patogenicidad potencial sobre Dianthus caryophyllus (Caryophyllaceae Basal rots of Gypsophila paniculata (Caryophyllaceae: Causal agents and its potential pathogenicity on Dianthus caryophyllus (Caryophyllaceae

    Directory of Open Access Journals (Sweden)

    Silvia María Wolcan

    Full Text Available Los objetivos del trabajo fueron identificar a los agentes causales de las podredumbres basales de Gypsophila paniculata en la Argentina y probar su posible patogenicidad sobre Dianthus caryophyllus . A partir de plantas con síntomas de «podredumbre de la corona» (la más importante se aislaron en orden decreciente: Fusarium solani , F. oxysporum , Phytophthora nicotianae , Rhizoctonia solani , F. graminearum , F. verticillioides, F. equiseti y Pythium sp. y de plantas con «podredumbre basal del tallo» F. graminearum , F. oxysporum y F. solani . Con distintas cepas de cada hongo se hicieron pruebas de patogenicidad mediante la infestación del suelo y el depósito de inóculo en heridas producidas en los tallos. En la «podredumbre de la corona» fueron patógenos P. nicotianae causando decaimiento rápido de la parte aérea y podredumbre blanda de la corona y R. solani causando una pudrición más lenta y tejidos desintegrados. F. graminearum fue el patógeno de la «podredumbre basal del tallo» de gipsofila, que se describe por primera vez en este hospedante , comprobando que el hongo penetra sólo por heridas del tallo. En condiciones de inoculación se confirmó que algunas cepas de R. solani y de F. graminearum aisladas de gipsofila pueden ser patógenas de clavel mientras que sólo algunas de P. nicotianae resultaron patógenas débiles.The aims of the paper were to determine the causal agents of basal rots of Gypsophila paniculata in Argentina, and to evaluate its possible pathogenicity on Dianthus caryophyllus. Fusarium solani, F. oxysporum , Phytophthora nicotianae , Rhizoctonia solani , F. graminearum , F. verticilloides, F. equiseti and Pythium sp. were isolated in decreasing order from plants with symptoms of «crown rot» (the major basal rot. F. graminearum , F. oxysporum and F. solani were isolated from plants with «basal stem rot». Inoculations of gypsophila were performed by soil infestation and by placing inoculum on

  7. Tetracycline-resistance encoding plasmids from Paenibacillus larvae, the causal agent of American foulbrood disease, isolated from commercial honeys.

    Science.gov (United States)

    Alippi, Adriana M; León, Ignacio E; López, Ana C

    2014-03-01

    Paenibacillus larvae, the causal agent of American foulbrood disease in honeybees, acquires tetracycline-resistance via native plasmids carrying known tetracycline-resistance determinants. From three P. larvae tetracycline-resistant strains isolated from honeys, 5-kb-circular plasmids with almost identical sequences, designated pPL373 in strain PL373, pPL374 in strain PL374, and pPL395 in strain PL395, were isolated. These plasmids were highly similar (99%) to small tetracycline-encoding plasmids (pMA67, pBHS24, pBSDMV46A, pDMV2, pSU1, pAST4, and pLS55) that replicate by the rolling circle mechanism. Nucleotide sequences comparisons showed that pPL373, pPL374, and pPL395 mainly differed from the previously reported P. larvae plasmid pMA67 in the oriT region and mob genes. These differences suggest alternative mobilization and/or conjugation capacities. Plasmids pPL373, pPL374, and pPL395 were individually transferred by electroporation and stably maintained in tetracycline-susceptible P. larvae NRRL B-14154, in which they autonomously replicated. The presence of nearly identical plasmids in five different genera of gram-positive bacteria, i.e., Bhargavaea, Bacillus, Lactobacillus, Paenibacillus, and Sporosarcina, inhabiting diverse ecological niches provides further evidence of the genetic transfer of tetracycline resistance among environmental bacteria from soils, food, and marine habitats and from pathogenic bacteria such as P. larvae. PMID:25296446

  8. El Escudete de la aceituna II: caracterización morfológica, fisiológica y patogénica del agente causal

    OpenAIRE

    Trapero Casas, Antonio; González, N.

    2006-01-01

    Morphological observations on the causal agent of the Dalmatian disease of olive fruits in Andalucia, southern Spain, confirm its identification as Camarosporium dalmaticum. This species was identified in Greece and it has been recently reclassified as Botryosphaeria dothidea (anamorph Fusicoccum aesculi). Physiological characterization of the pathogen demonstrated that the fungus has a wide range of temperatures for growth and germination of conidia. The optimum temperature was 26ºC for grow...

  9. Exploring Mechanisms of Resistance to Respiratory Inhibitors in Field Strains of Botrytis cinerea, the Causal Agent of Gray Mold ▿ †

    OpenAIRE

    Leroux, Pierre; Gredt, Michel; Leroch, Michaela; Walker, Anne-Sophie

    2010-01-01

    Respiratory inhibitors are among the fungicides most widely used for disease control on crops. Most are strobilurins and carboxamides, inhibiting the cytochrome b of mitochondrial complex III and the succinate dehydrogenase of mitochondrial complex II, respectively. A few years after the approval of these inhibitors for use on grapevines, field isolates of Botrytis cinerea, the causal agent of gray mold, resistant to one or both of these classes of fungicide were recovered in France and Germa...

  10. Evidence Suggesting that Fasciola gigantica Might be the Most Prevalent Causal Agent of Fascioliasis in Northern Iran

    Directory of Open Access Journals (Sweden)

    K Ashrafi

    2004-10-01

    out and all trematodes recovered at necropsy, 8 weeks post-exposure, appeared to be F. gigantica based on morphology. The high temperature, moisture and rainfall during the year, especially in Bandar-Anzali, support the establishment and transmission of the disease in the zone. Although the species involved in human infections in endemic areas of Gilan has been usually referred to as F. hepatica, the results of this study as well as some interesting epidemiological evidences related to the disease, support that Fasciola gigantica might be the main causal agent of fascioliasis in this important endemic zone.

  11. Functional and biophysical studies on four ceratoplatanins from the fungus Moniliophthora perniciosa, causal agent of the Witche's broom disease

    International Nuclear Information System (INIS)

    Full text: Ceratoplatanin (CP) is a secreted protein of 12.4 kDa initially identified in culture filtrates of the disease ascomycete Ceratocystis fimbriata f. sp. platani, etiological agent of the canker stain disease. CP is also the founding member of the namesake protein family, which contains fungal-secreted proteins involved in various stages of the host-fungus interaction and may act as phytotoxins or elicitors of defense response. Besides the low molecular weight, CPs have a high percentage of hydrophobic residues and share two conserved intramolecular disulfide bonds. It has been suggested that CPs have important physiological functions, including interaction with cell wall or cell membrane and manipulation of the host's defense system. Furthermore, a recent work showed that the ceratoplatanin from C. fimbriata has some degree of affinity for the saccharide 4-N-acetylglucosamine. However, its precise molecular function remains elusive. Five putative CPs have been identified in Moniliophthora perniciosa a basidiomycete fungus responsible for great economic losses in cocoa industry in the form of Witches' broom disease (WBD) , four of which had their crystal structures resolved by our group. In this work we report biophysical and functional studies on these MpCPs aiming at understanding their role and importance during the WBD progression. (author)

  12. Causality in Classical Electrodynamics

    Science.gov (United States)

    Savage, Craig

    2012-01-01

    Causality in electrodynamics is a subject of some confusion, especially regarding the application of Faraday's law and the Ampere-Maxwell law. This has led to the suggestion that we should not teach students that electric and magnetic fields can cause each other, but rather focus on charges and currents as the causal agents. In this paper I argue…

  13. Identificación del agente causal de la pudrición blanca en Morelos, México

    Directory of Open Access Journals (Sweden)

    Ernesto Hernández Mendieta

    2013-12-01

    Full Text Available Título en ingles: Identification of the white rot agent in Morelos, MexicoTítulo corto: Agente causal de la pudrición blanca en Morelos, MéxicoResumen: Cepas aisladas de Trametes versicolor (L.:Fr. Pilát causando pudrición blanca en especies arbóreas de amate amarillo (Ficus petiolaris, cirián o cuatecomate (Crescentia alata, guayaba (Psidium guajava y sauce colorado (Salix humboltiana en los municipios de Ayala, Cuautla, Cuernavaca, Jojutla, Tepalcingo, Tlaltizapán, Tlaquiltenango y Zacatepec de Hidalgo en el estado de Morelos, México se desarrollaron en medio de cultivo agua-agar enriquecido con 2,4-D amina en concentraciones de 0, 50, 100, 150, 250, 500, 1000, 2000, 3000, 4000 y 5000 ppm, con el objetivo de conocer su desarrollo en esta sal. Los mejores resultados se obtuvieron en un intervalo de 50 a 1000 ppm con un óptimo de 500 a 1000 ppm.L, las concentraciones de 2000 a 5000 ppm inhiben el desarrollo del hongo. Se confirma que las cepas aisladas de T. versicolor pueden emplearse como herramienta potencial de biorremediación de aguas contaminadas por ácido 2,4-D que es empleado como herbicida para el control de malezas de hoja ancha en cultivos de maíz, arroz, caña de azúcar y sorgo en la región de estudio.Palabras clave: Trametes versicolor, identificación, ácido 2,4-diclorofenoxiacetico, 2,4-D.Abstract: Trametes versicolor (L.: Fr Pilát was identified causing white rot of hardwood tree species of amate amarillo (Ficus petiolaris, cuatecomate or cirián (Crescentia alata, guayava (Psidium guajava and sauce colorado (Salix humboltiana in municipalities of Ayala, Cuautla, Cuernavaca, Jojutla Tepalcingo Tlaltizapan, Tlaquiltenango and Zacatepec de Hidalgo in the state of Morelos, Mexico. Collected strains were grown in water-agar culture medium with 2,4-D amine at concentrations of 0, 50, 100, 150, 250, 500, 1000, 2000, 3000, 4000 and 5000 ppm with the aim of know their growth in this salt. The best results were found

  14. Causality in Europeanization Research

    DEFF Research Database (Denmark)

    Lynggaard, Kennet

    2012-01-01

    Discourse analysis as a methodology is perhaps not readily associated with substantive causality claims. At the same time the study of discourses is very much the study of conceptions of causal relations among a set, or sets, of agents. Within Europeanization research we have seen endeavours to......, it suggests that discourse analysis and the study of causality are by no means opposites. The study of Europeanization discourses may even be seen as an essential step in the move towards claims of causality in Europeanization research. This chapter deals with the question of how we may move from the...

  15. Rickettsia typhi IN RODENTS AND R. felis IN FLEAS IN YUCATÁN AS A POSSIBLE CAUSAL AGENT OF UNDEFINED FEBRILE CASES

    OpenAIRE

    PENICHE-LARA, Gaspar; Dzul-Rosado, Karla; PÉREZ-OSORIO, Carlos; Zavala-Castro, Jorge

    2015-01-01

    Rickettsia typhi is the causal agent of murine typhus; a worldwide zoonotic and vector-borne infectious disease, commonly associated with the presence of domestic and wild rodents. Human cases of murine typhus in the state of Yucatán are frequent. However, there is no evidence of the presence of Rickettsia typhi in mammals or vectors in Yucatán. The presence of Rickettsia in rodents and their ectoparasites was evaluated in a small municipality of Yucatán using the conventional polymerase chai...

  16. Characterization of an RTX-Like Toxin and an Alpha-2-Macroglobulin in Pantoea stewartii subsp. stewartii, Causal Agent of Stewart's Wilt of Sweet Corn

    OpenAIRE

    Williams, Kayla Marie

    2014-01-01

    Pantoea stewartii subsp. stewartii DC283, the causal agent of Stewart's wilt, is an important bacterial pathogen of sweet corn. P. stewartii colonizes the apoplastic space and xylem tissue, resulting in characteristic water-soaked (WS) lesions and wilting. A gene encoding a putative RTX-like toxin, rtx2, has been identified in P. stewartii. RTX toxins belong to the pore-forming toxin family and have lytic properties in animal systems. Little is known about the role of RTX toxins in plant path...

  17. Actividad antifúngica del quitosano y aceites esenciales sobre Rhizopus stolonifer (Ehrenb.:Fr.) Vuill., agente causal de la pudrición blanda del tomate

    OpenAIRE

    Alejandra María Alvarado Hernández; Laura Leticia Barrera Necha; Ana Niurka Hernández Lauzardo; Miguel Gerardo Velázquez del Valle

    2011-01-01

    Rhizopus stolonifer es el agente causal de la pudrición blanda, enfermedad poscosecha que ocasiona pérdidas económicas importantes. Se han empleado fungicidas sintéticos como el dicloran para controlar a este microorganismo, sin embargo, se ha demostrado que los fungicidas representan un riesgo para el ambiente y la salud humana. Actualmente se buscan alternativas naturales para el control de las pudriciones poscosecha. Se evaluó in vitro e in situ el efecto antifúngico del quitosano y de los...

  18. Species-Specific Detection and Identification of Fusarium Species Complex, the Causal Agent of Sugarcane Pokkah Boeng in China

    OpenAIRE

    Zhenyue Lin; Shiqiang Xu; Youxiong Que; Jihua Wang; Comstock, Jack C.; Jinjin Wei; McCord, Per H.; Baoshan Chen; Rukai Chen; Muqing Zhang

    2014-01-01

    BACKGROUND: Pokkah boeng disease caused by the Fusarium species complex results in significant yield losses in sugarcane. Thus, the rapid and accurate detection and identification of the pathogen is urgently required to manage and prevent the spreading of sugarcane pokkah boeng. METHODS: A total of 101 isolates were recovered from the pokkah boeng samples collected from five major sugarcane production areas in China throughout 2012 and 2013. The causal pathogen was identified by morphological...

  19. Efecto depresivo de los agentes causales de las pudriciones secas en plantas producidas in vitro de malanga (Xanthosoma sagittifolium

    Directory of Open Access Journals (Sweden)

    Ernesto Espinosa Cuellar

    2012-06-01

    Full Text Available Título en ingles: Depressive effect of the causative agents of dry rot in plants grown in vitro from malanga (Xanthosoma sagittifolium Resumen Se determinó el efecto depresivo sobre plantas de malanga producidas in vitro del cultivar “Amarilla Especial”, de los hongos Fusarium oxysporum Schlecht, Rhizoctonia solani  Kühn y Sclerotium rolfsii Sacc  aislados de plantas infectadas que presentaban síntomas de escaso desarrollo, clorosis, necrosis foliar y pudrición de las raíces. Los tratamientos consistieron en el aislamiento de los tres hongos por separado, la mezcla de los tres hongos y un control sin inocular. Se plantaron plantas previamente aclimatizadas en cámaras que tenían una dimensión de 0,90 x 0,90 x 0,90 m, en bloque completamente al azar con cuatro réplicas. Se inocularon 100 plantas por cada tratamiento y como control se dejaron igual número de plantas sin inocular, se evaluó en cada caso la altura de la planta, el número de raíces por planta y el número de raíces enfermas, y posteriormente se determinó el peso fresco y seco de las raíces y el follaje. Se cosechó a los 10 meses después de la plantación y se evaluaron algunos componentes del rendimiento, como el número de cormos y cormelos y su peso fresco, al igual que la intensidad de los daños en el momento de la cosecha. Los resultados mostraron que los hongos fitopatógenos Fusarium oxysporum Schlecht, Rhizoctonia solani  Kühn y Sclerotium rolfsii Sacc asociados a las pudriciones secas, ocasionaron un efecto depresivo en las plantas de malanga producidas in vitro cultivadas en cámaras. La mezcla de estos tres hongos resultó muy agresiva, lo que provocó en las plantas una disminución en la altura, el peso fresco del follaje y en el número de raíces, cormos y cormelos. Palabras clave: malanga, pudriciones secas, hongos, Abstract Depressive effect was determined on plants produced in vitro taro cultivar 'Amarilla Especial', fungi Fusarium

  20. Effect of bodily fluids from honey bee (Apis mellifera) larvae on growth and genome-wide transcriptional response of the causal agent of American Foulbrood disease (Paenibacillus larvae).

    Science.gov (United States)

    De Smet, Lina; De Koker, Dieter; Hawley, Alyse K; Foster, Leonard J; De Vos, Paul; de Graaf, Dirk C

    2014-01-01

    Paenibacillus larvae, the causal agent of American Foulbrood disease (AFB), affects honey bee health worldwide. The present study investigates the effect of bodily fluids from honey bee larvae on growth velocity and transcription for this Gram-positive, endospore-forming bacterium. It was observed that larval fluids accelerate the growth and lead to higher bacterial densities during stationary phase. The genome-wide transcriptional response of in vitro cultures of P. larvae to larval fluids was studied by microarray technology. Early responses of P. larvae to larval fluids are characterized by a general down-regulation of oligopeptide and sugar transporter genes, as well as by amino acid and carbohydrate metabolic genes, among others. Late responses are dominated by general down-regulation of sporulation genes and up-regulation of phage-related genes. A theoretical mechanism of carbon catabolite repression is discussed. PMID:24586572

  1. Preservação de urediniósporos de Puccinia melanocephala, agente causal de ferrugem em cana-de-açúcar Preservation of uredospores of Puccinia melanocephala, the causal agent of sugarcane rust

    Directory of Open Access Journals (Sweden)

    Ely Oliveira Garcia

    2007-06-01

    Full Text Available A sazonalidade na manifestação da ferrugem da cana dificulta a obtenção de esporos em quantidades adequadas para inoculações em qualquer época do ano, restringindo os trabalhos envolvendo o patógeno aos meses nos quais a doença esta presente no campo. O trabalho visou desenvolver uma metodologia para preservar os esporos por períodos prolongados, mantendo sua viabilidade e infectividade. Esporos foram coletados a partir de folhas naturalmente infectadas, com bomba de vácuo. Parte dos esporos foi desidratada por liofilização ou em sílica gel e outra parte não passou por desidratação. Armazenaram-se estes esporos em diferentes temperaturas (temp. ambiente, 5ºC, -20 ºC, -80ºC. Periodicamente, a viabilidade dos esporos foi avaliada por meio de plaqueamento em ágar-água. Após o quarto mês, foi também avaliada a infectividade dos esporos armazenados por meio de inoculações na variedade suscetível SP70-1143, seguida da avaliação da área foliar atacada. Os esporos armazenados à temperatura ambiente e a 5ºC, independentemente da desidratação, permaneceram viáveis por períodos máximos de 1 mês e 2 meses, respectivamente. Os melhores tratamentos consistiram na desidratação em sílica gel, seguida pelo armazenamento à -20ºC e -80ºC. Mesmo após um ano de armazenamento nestas condições, os esporos provocaram ferrugem nas plantas inoculadas, em níveis de severidade adequados para um teste de discriminação de reações à ferrugem.The seasonality in the appearance of sugarcane rust makes it difficult to obtain in any season of year, adequate quantities uredospores for artificial inoculations in a breeding program. This research aimed to develop a long-term storage methodology to preserve uredospores of Puccicinia melanocephala to keep their viability and infectivity. Uredospores were collect using a vacuum pump from naturally rusted leaves. Part of these uredospores was dehydrated in silica gel or lyophilized

  2. Murcha do manjericão (Ocimum basilicum) no Brasil: agente causal, círculo de plantas hospedeiras e transmissão via semente Sweet basil (Ocimum basilicum) wilt in Brazil: causal agent, host range and seed transmission

    OpenAIRE

    Ailton Reis; Bruno Eduardo Cardoso Miranda; Leonardo Silva Boiteux; Gilmar Paulo Henz

    2007-01-01

    O manjericão (Ocimum basilicum L.) é uma hortaliça da família Lamiaceae, utilizada na culinária ou como matéria prima para a indústria de fármacos e óleos essenciais. Amostras de plantas de manjericão apresentando sintomas de murcha, seca de hastes e podridão de colo foram coletadas na área rural de Brazlândia (DF) durante a estação chuvosa de 2005. Outras duas amostras foram coletadas em plantas cultivadas em campo aberto e casas de vegetação na região de Ponte Alta (DF). Isolados de um fung...

  3. Isolation and identification of Avibacterium paragallinarum, the causal agent of infectious coryza (IC) from layer chickens in Bangladesh

    OpenAIRE

    Akter, S.; Ali, M.; Das, P.M; Hossain, M. M.

    2013-01-01

    This study was carried out for the isolation and identification of Avibacterium paragallinarum, the etiological agent of infectious coryza (IC). Pathological changes were also investigated that occurred in organs in layer chickens obtained from some selected areas of Bangladesh. A nasal swabs (n=30) from dead chickens and four swabs from live chickens were collected aseptically. The organisms from swabs were cultured in different media, stained, and followed by sugar fermentation and biochemi...

  4. Glucanases and chitinases as causal agents in the protection of Acacia extrafloral nectar from infestation by phytopathogens.

    Science.gov (United States)

    González-Teuber, Marcia; Pozo, María J; Muck, Alexander; Svatos, Ales; Adame-Alvarez, Rosa M; Heil, Martin

    2010-03-01

    Nectars are rich in primary metabolites and attract mutualistic animals, which serve as pollinators or as an indirect defense against herbivores. Their chemical composition makes nectars prone to microbial infestation. As protective strategy, floral nectar of ornamental tobacco (Nicotiana langsdorffii x Nicotiana sanderae) contains "nectarins," proteins producing reactive oxygen species such as hydrogen peroxide. By contrast, pathogenesis-related (PR) proteins were detected in Acacia extrafloral nectar (EFN), which is secreted in the context of defensive ant-plant mutualisms. We investigated whether these PR proteins protect EFN from phytopathogens. Five sympatric species (Acacia cornigera, A. hindsii, A. collinsii, A. farnesiana, and Prosopis juliflora) were compared that differ in their ant-plant mutualism. EFN of myrmecophytes, which are obligate ant-plants that secrete EFN constitutively to nourish specialized ant inhabitants, significantly inhibited the growth of four out of six tested phytopathogenic microorganisms. By contrast, EFN of nonmyrmecophytes, which is secreted only transiently in response to herbivory, did not exhibit a detectable inhibitory activity. Combining two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis with nanoflow liquid chromatography-tandem mass spectrometry analysis confirmed that PR proteins represented over 90% of all proteins in myrmecophyte EFN. The inhibition of microbial growth was exerted by the protein fraction, but not the small metabolites of this EFN, and disappeared when nectar was heated. In-gel assays demonstrated the activity of acidic and basic chitinases in all EFNs, whereas glucanases were detected only in EFN of myrmecophytes. Our results demonstrate that PR proteins causally underlie the protection of Acacia EFN from microorganisms and that acidic and basic glucanases likely represent the most important prerequisite in this defensive function. PMID:20023149

  5. Diversity of endophytic fungal community of cacao (Theobroma cacao L. and biological control of Crinipellis perniciosa, causal agent of Witches' Broom Disease

    Directory of Open Access Journals (Sweden)

    2005-02-01

    Full Text Available The basidiomycete fungus Crinipellis perniciosa (Stahel Singer is the causal agent of Witches' Broom Disease of Cacao (Theobroma cacao L. which is the main factor limiting cacao production in the Americas. Pod losses of up to 90% are experienced in affected areas as evidenced by the 50% drop in production in Bahia province, Brazil following the arrival of the C. perniciosa in the area in 1989. The disease has proven particularly difficult to control and many farmers in affected areas have given up cacao cultivation. In order to evaluate the potential of endophytes as a biological control agent of this phytopathogen, the endophytic fungal community of resistant and susceptible cacao plants as well as affected branches was studied between 2001 and 2002. The fungal community was identified by morphological traits and rDNA sequencing as belonging to the genera Acremonium, Blastomyces, Botryosphaeria, Cladosporium, Colletotrichum, Cordyceps, Diaporthe, Fusarium, Geotrichum, Gibberella, Gliocladium, Lasiodiplodia, Monilochoetes, Nectria, Pestalotiopsis, Phomopsis, Pleurotus, Pseudofusarium, Rhizopycnis, Syncephalastrum, Trichoderma, Verticillium and Xylaria. These fungi were evaluated both in vitro and in vivo by their ability to inhibit C. perniciosa. Among these, some were identified as potential antagonists, but only one fungus (Gliocladium catenulatum reduced the incidence of Witches' Broom Disease in cacao seedlings to 70%.

  6. Effect of Two Biological Formulations Based on Bacillus subtilis and Pseudomonas fluorescens on Control of Didymella applanata, the Causal Agent of Red Raspberry Cane Spur Blight

    Directory of Open Access Journals (Sweden)

    Margarita Shternshis

    2016-01-01

    Full Text Available In vitro and in vivo studies were conducted to estimate the efficacy of the two microbial formulations based on Bacillus subtilis Cohn. and Pseudomonas fluorescens Mig. on the fungus Didymella applanata (Niessl. Sacc., the causal agent of red raspberry (Rubus idaeus L. spur blight. In vitro, both bacteria reduced the growth of D. applanata. In inoculation experiments with raspberry canes in two cultivars with different susceptibility to D. applanata, these antagonistic bacteria suppressed fungal development by reducing the lesions area and the number of D. applanata fruiting bodies. Field trials of two biological formulations under natural conditions showed a significant suppression of the disease. B. subtilis and P. fluorescens included in the formulations revealed antagonistic activity towards D. applanata that depended on the red raspberry cultivar and weather conditions. In all cases, B. subtilis showed better results than P. fluorescens in biocontrol of the raspberry spur blight. This study demonstrated for the first time the ability of the biocontrol agents B. subtilis and P. fluorescens to suppress red raspberry cane spur blight, a serious worldwide disease.

  7. Causal mapping

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2006-01-01

    The lecture note explains how to use the causal mapping method as well as the theoretical framework aoosciated to the method......The lecture note explains how to use the causal mapping method as well as the theoretical framework aoosciated to the method...

  8. Comparison of antifungal activities of various essential oils on the Phytophthora drechsleri, the causal agent of fruit decay

    Directory of Open Access Journals (Sweden)

    Ali Mohammadi

    2015-10-01

    Full Text Available Background and Objectives: The efficacy of Mentha piperita L, Zataria multiflora Boiss and Thymus vulgaris L essential oils (EOs was evaluated for controlling the growth of Phytophthora drechsleri, the causative agent of damage to many crops that is consumed directly by humans.Materials and Methods: The EOs used in this study was purchased from Magnolia Co, Iran. The pour plate method in petri dishes containing Potato Dextrose Agar (PDA was used to evaluate the antifungal properties of EOs. The minimal inhibitory concentrations (MIC, minimum fungicidal concentration (MFC as well as mycelial growth inhibition (MGI were measured. The IC50 value (the concentration inhibited 50% of the mycelium growth was calculated by probit analysis.Results and Conclusion: The fungal growth was significantly reduced by increasing concentrations of tested EOs. The complete reduction was obtained with Shirazi thyme at all concentrations, whereas the complete reduction for peppermint and thyme was observed at 0.4% and 0.8% (v/v concentrations, respectively. Meanwhile, the minimum inhibition wasobserved when 0.1% peppermint (MGI values of 9.37% was used. The IC50, MIC and MFC values of Shirazi thyme was 0.053, 0.1% and 0.2%, respectively. Similarly, MIC and MFC values of peppermint and thyme were recorded 0.4% and 0.8%, respectively. The results obtained from this study may contribute to the development of new antifungal agents to protect the crops from this pathogenic fungus and many agricultural plant pathogens causing drastic crop losses.

  9. Actividad antifúngica del quitosano y aceites esenciales sobre Rhizopus stolonifer (Ehrenb.:Fr. Vuill., agente causal de la pudrición blanda del tomate

    Directory of Open Access Journals (Sweden)

    Alejandra María Alvarado Hernández

    2012-06-01

    Full Text Available Título en ingles: Antifungal activity of chitosan and essential oils on Rhizopus stolonifer (Ehrenb.:Fr. Vuill causal agent of soft rot of tomato ResumenRhizopus stolonifer es el agente causal de la pudrición blanda, enfermedad poscosecha que ocasiona pérdidas económicas importantes. Se han empleado fungicidas sintéticos como el dicloran para controlar a este microorganismo, sin embargo, se ha demostrado que los fungicidas representan un riesgo para el ambiente y la salud humana. Actualmente se buscan alternativas naturales para el control de las pudriciones poscosecha. Se evaluó in vitro e in situ el efecto antifúngico del quitosano y de los aceites esenciales de canela (Cinnamomum zeylanicum, clavo (Syzygium aromaticum y tomillo (Thymus vulgaris y dicloran sobre Rhizopus stolonifer. Los tratamientos más efectivos para inhibir in vitro a Rhizopus stolonifer fueron obtenidos con quitosano a 10 mg mL-1, con los tres aceites esenciales probados a la concentración de  0,3 mg mL-1, las mezclas de quitosano a 10 mg mL-1 con los aceites a 0,3 mg mL-1 y el dicloran a 1 mg mL-1. Los experimentos in situ mostraron que el tratamiento individual con quitosano fue el mejor para reducir el porcentaje de infección de los frutos de tomate (Lycopersicon esculentum inoculados con Rhizopus stolonifer y que la mezcla de quitosano con aceites esenciales no mejora la actividad antifúngica. El quitosano y el dicloran fueron los mejores tratamientos para reducir la pérdida de peso de los frutos. Los tratamientos individuales con quitosano representan una alternativa natural para controlar la pudrición blanda en frutos de tomate. Palabras clave: quitosano; aceites esenciales; Rhizopus stolonifer; podredumbre blanda. AbstractRhizopus stolonifer is the causal agent of soft rot, postharvest disease that causes important economic losses. Synthetic fungicides such as dichloran have been used to control this microorganism; however, it has been shown that

  10. Suberin Regulates the Production of Cellulolytic Enzymes in Streptomyces scabiei, the Causal Agent of Potato Common Scab.

    Science.gov (United States)

    Padilla-Reynaud, Rebeca; Simao-Beaunoir, Anne-Marie; Lerat, Sylvain; Bernards, Mark A; Beaulieu, Carole

    2015-01-01

    Suberin, a major constituent of the potato periderm, is known to promote the production of thaxtomins, the key virulence factors of the common scab-causing agent Streptomyces scabiei. In the present study, we speculated that suberin affected the production of glycosyl hydrolases, such as cellulases, by S. scabiei, and demonstrated that suberin promoted glycosyl hydrolase activity when added to cellulose-, xylan-, or lichenin-containing media. Furthermore, secretome analyses revealed that the addition of suberin to a cellulose-containing medium increased the production of glycosyl hydrolases. For example, the production of 13 out of the 14 cellulases produced by S. scabiei in cellulose-containing medium was stimulated by the presence of suberin. In most cases, the transcription of the corresponding cellulase-encoding genes was also markedly increased when the bacterium was grown in the presence of suberin and cellulose. The level of a subtilase-like protease inhibitor was markedly decreased by the presence of suberin. We proposed a model for the onset of S. scabiei virulence mechanisms by both cellulose and suberin, the main degradation product of cellulose that acts as an inducer of thaxtomin biosynthetic genes, and suberin promoting the biosynthesis of secondary metabolites including thaxtomins. PMID:26330095

  11. A review of the Mycrocylus ulei Ascomycetes fungus, causative agent of South American rubber-leaf blight Revisión sobre el hongo Microcyclus ulei, agente causal del mal suramericano de la hoja del caucho

    Directory of Open Access Journals (Sweden)

    Ancízar Aristizábar Fabio

    2006-12-01

    Full Text Available The Microcyclus ulei Ascomycetes fungus is the causal agent of south-American leaf blight (SALB, this being one of the most important diseases affecting the natural rubber tree (Hevea brasiliensis in Latina-America and has been responsible for numerous economic losses. This fungus has presented high physiological variability, suggesting its great adaptability. HCN tolerance has been described as being one of the mechanisms associated with its virulence. Resistant Hevea clones have been obtained by genetic improvement; however, the mechanisms associated with this are still not well known. Greater knowledge of this pathogen will lead to developing new control strategies and better understanding of the mechanisms associated with host resistance. Key words: Microcyclus ulei, SALB, Hevea brasiliensis.El hongo ascomycete Microcyclus ulei es el agente causal del SALB que es una de las enfermedades más importan­tes del árbol de caucho natural (Hevea brasiliensis en América Latina y ha sido responsable de numerosas pérdidas económicas. Este hongo ha presentado alta variabilidad fisiológica y se sugiere su alta adaptabilidad, dentro de los mecanismos asociados a su virulencia se ha descrito la tolerancia al HCN. Se han obtenido clones de Hevea resistentes mediante mejoramiento genético, sin embargo, aun no son bien conocidos los mecanismos asociados a ésta. Un mayor conocimiento de este patógeno permitirá el desarrollo de nuevas estrategias de control así como el mayor entendimiento de los mecanismos asociados a resistencia del hospedero. Palabras clave: Microcyclus ulei, SALB, Hevea brasiliensis.

  12. Biological Control of Rhizoctonia solani, the Causal Agent of Rice Sheath Blight by Antagonistics Bacteria in Greenhouse and Field Conditions

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    Mostapha Niknejad Kazempour

    2004-01-01

    Full Text Available Pseudomonas fluorescens isolates that inhibited growth of Rhizoctonia solani Kühn, the rice sheath blight pathogen were collected the rhizosplane and surrounding soil of healthy and rice sheath blight disease in farming of the Guilan province, Iran. Two hundred eighty eight isolates tested and among them only antagonistic ability of 8 isolates were demonstrated by using the dual culture method. According to the results of biochemical and morphological trials all isolates were identified as P. fluorescens biovar 3. By determining the effects of volatile metabolites, secretion of extracellular and antibiotics of these isolates inhibited mycelial growth of R. solani in vitro. All P. fluorescens isolates produced siderophore on King`s medium B, inhibited the mycelial growth of the R. solani. Antagonistics isolates reduced the germination and cause the lysis of sclerotia of R. solani. In greenhouse conditions antagonistic isolates were used by seed coating, soil drenching and foliar spray. Statistical analysis of data indicated that there existed significant differences between seed, soil and plant treatments. All of the isolates in seed coating are more effective. In the field conditions foliar spray of isolate B41 mixed with benlate were applied. The disease intensity in B41 isolate for seed coating, soil drenching and seed coating + foliar spray were 10.5, 11.75 and 18.75%, respectively, while the control plants showed 52% disease intensity. These results suggest that the P. fluorescens isolates studied have an excellent potential to be used as biocontrol agents of R. solani in rice at the field conditions.

  13. Biological Control of Sclerotinia sclerotiorum, Causal Agent of Sunflower Head and Stem Rot Disease, by Use of Soil borne Actinomycetes Isolates

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    F. Baniasadi

    2009-01-01

    Full Text Available Problem statement: High level of biosafety and non adverse effects on the environment of biocontrol strategies of pest management, are priorities of tomorrow's world agriculture. Actinomycetes are active biocontrol agents due to their antagonistic properties against wide range of plant pathogens particularly fungi. Fungal pathogens are liable for a big part of damages in agriculture economy. Approach: In the present research antifungal bioactivity of 50 isolates of Actinomycetes collected from soils of Kerman province of Iran was investigated against Sclerotinia sclerotiorum (Lib., the causal agent of stem rot in sunflower, through agar disc method and dual culture bioassays. The Streptomyces isolate No. 363 was propagated in submerged cultures and active crude was prepared upon which several biological characterizations performed. Greenhouse studies were achieved to confirm laboratory results. Results: Among the tested Streptomyces isolates, 10 isolates revealed antagonistic properties in dual culture procedure from which isolate No. 363 showed highest bioactivity. The active metabolite of Streptomyces isolate No. 363 was polar and well soluble in H2O. Using agar-disc method, progressive growth of the pathogen was highly reduced by the antagonist through exhibiting ability to constitute fungus-free zones of inhibitions. The results indicated that isolate No. 363 was a proper candidate for field biocontrol studies. Conclusion: Results may open a horizon for production of resistant transgenic plants having antifungal properties originated from biologically active Streptomyces spp. recognition and production of effective metabolite(s of Streptomyces spp. which was responsible for antifungal activities will be our commercial goal due to rich reserves of soil borne Actinomycetes in Iran.

  14. Rickettsia typhi IN RODENTS AND R. felis IN FLEAS IN YUCATÁN AS A POSSIBLE CAUSAL AGENT OF UNDEFINED FEBRILE CASES

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    Gaspar PENICHE-LARA

    2015-04-01

    Full Text Available Rickettsia typhi is the causal agent of murine typhus; a worldwide zoonotic and vector-borne infectious disease, commonly associated with the presence of domestic and wild rodents. Human cases of murine typhus in the state of Yucatán are frequent. However, there is no evidence of the presence of Rickettsia typhi in mammals or vectors in Yucatán. The presence of Rickettsia in rodents and their ectoparasites was evaluated in a small municipality of Yucatán using the conventional polymerase chain reaction technique and sequencing. The study only identified the presence of Rickettsia typhi in blood samples obtained from Rattus rattus and it reported, for the first time, the presence of R. felis in the flea Polygenis odiosus collected from Ototylomys phyllotis rodent. Additionally, Rickettsia felis was detected in the ectoparasite Ctenocephalides felis fleas parasitizing the wild rodent Peromyscus yucatanicus. This study’s results contributed to a better knowledge of Rickettsia epidemiology in Yucatán.

  15. In vitro antibacterial effect of exotic plants essential oils on the honeybee pathogen Paenibacillus larvae, causal agent of American foul brood

    Energy Technology Data Exchange (ETDEWEB)

    Fuselli, S. R.; Garcia de la Rosa, S. B.; Eguaras, M. J.; Fritz, R.

    2010-07-01

    Chemical composition and antimicrobial activity of exotic plants essential oils to potentially control Paenibacillus larvae, the causal agent of American foul brood disease (AFB) were determined. AFB represents one of the main plagues that affect the colonies of honeybees Apis mellifera L. with high negative impact on beekeepers worldwide. Essential oils tested were niaouli (Melaleuca viridiflora) and tea tree (Melaleuca alternifolia) from Myrtaceae, and citronella grass (Cymbopogon nardus) and palmarosa (Cymbopogon martinii) from Gramineae. The components of the essential oils were identified by SPME-GC/MS analysis. The antimicrobial activity of the oils against P. larvae was determined by the broth micro dilution method. In vitro assays of M. viridiflora and C. nardus oils showed the inhibition of the bacterial strains at the lowest concentrations tested, with minimal inhibitory concentration (MIC) mean value about 320 mg L{sup -}1 for both oils, respectively. This property could be attributed to the kind and percentage of the components of the oils. Terpinen-4-ol (29.09%), {alpha}-pinene (21.63%) and limonene (17.4%) were predominant in M. viridiflora, while limonene (24.74%), citronelal (24.61%) and geraniol (15.79%) were the bulk of C. nardus. The use of these essential oils contributes to the screening of alternative natural compounds to control AFB in the apiaries; toxicological risks and other undesirable effects would be avoided as resistance factors, developed by the indiscriminate use of antibiotics. (Author) 40 refs.

  16. Post-transcriptional silencing of the SGE1 gene induced by a dsRNA hairpin in Fusarium oxysporum f. sp cubense, the causal agent of Panama disease.

    Science.gov (United States)

    Fernandes, J S; Angelo, P C S; Cruz, J C; Santos, J M M; Sousa, N R; Silva, G F

    2016-01-01

    Fusarium oxysporum f. sp cubense (Foc), the causal agent of Panama disease, is responsible for economic losses in banana crops worldwide. The identification of genes that effectively act on pathogenicity and/or virulence may contribute to the development of different strategies for disease control and the production of resistant plants. The objective of the current study was to analyze the importance of SGE1 gene expression in Foc virulence through post-transcriptional silencing using a double-stranded RNA hairpin. Thirteen transformants were selected based on different morphological characteristics, and sporulation in these transformants was significantly reduced by approximately 95% (P < 0.05) compared to that of the wild-type strain. The relative SGE1 expression levels in the transformant strains were reduced by 27 to 47% compared to those in the wild-type strain. A pathogenicity analysis revealed that the transformants were able to reach the rhizomes and pseudostems of the inoculated banana plants. However, the transformants induced initial disease symptoms in the banana plants approximately 10 days later than that by the wild-type Foc, and initial disease symptoms persisted even at 45 days after inoculation. These results indicate that the SGE1 gene is directly involved in the virulence of Foc. Therefore, SGE1 may be a potential candidate for host-induced gene silencing in banana plants. PMID:27173186

  17. Transmission of Pantoea ananatis and P. agglomerans, causal agents of center rot of onion (Allium cepa), by onion thrips (Thrips tabaci) through feces.

    Science.gov (United States)

    Dutta, B; Barman, A K; Srinivasan, R; Avci, U; Ullman, D E; Langston, D B; Gitaitis, R D

    2014-08-01

    Frankliniella fusca, the tobacco thrips, has been shown to acquire and transmit Pantoea ananatis, one of the causal agents of the center rot of onion. Although Thrips tabaci, the onion thrips, is a common pest of onions, its role as a vector of P. ananatis has been unknown. The bacterium, P. agglomerans, is also associated with the center rot of onion, but its transmission by thrips has not been previously investigated. In this study, we investigated the relationship of T. tabaci with P. ananatis and P. agglomerans. Surface-sterilized T. tabaci were provided with various acquisition access periods (AAP) on onion leaves inoculated with either P. ananatis or P. agglomerans. A positive exponential relationship was observed between thrips AAP duration and P. ananatis (R² = 0.967; P = 0.023) or P. agglomerans acquisition (R² = 0.958; P = 0.017). Transmission experiments conducted with T. tabaci adults indicated that 70% of the seedlings developed center rot symptoms 15 days after inoculation. Immunofluorescence microscopy with antibodies specific to P. ananatis revealed that the bacterium was localized only in the gut of T. tabaci adults. Mechanical inoculation of onion seedlings with fecal rinsates alone produced center rot but not with salivary secretions. Together these results suggested that T. tabaci could efficiently transmit P. ananatis and P. agglomerans. PMID:24548212

  18. Pharmacokinetics of chlorogenic acid and corydaline in DA-9701, a new botanical gastroprokinetic agent, in rats.

    Science.gov (United States)

    Jung, Ji Won; Kim, Ju Myung; Jeong, Jin Seok; Son, Miwon; Lee, Hye Suk; Lee, Myung Gull; Kang, Hee Eun

    2014-07-01

    1.Few studies describing the pharmacokinetic properties of chlorogenic acid (CA) and corydaline (CRD) which are marker compounds of a new prokinetic botanical agent, DA-9701, have been reported. The aim of the present study is to evaluate the pharmacokinetic properties CA and CRD following intravenous and oral administration of pure CA (1-8 mg/kg) or CRD (1.1-4.5 mg/kg) and their equivalent dose of DA-9701 to rats. 2.  Dose-proportional AUC and dose-independent clearance (10.3-12.1 ml/min/kg) of CA were observed following its administration. Oral administration of CA as DA-9701 did not influence the oral pharmacokinetic parameters of CA. Incomplete absorption of CA, its decomposition in the gastrointestinal tract, and/or pre-systemic metabolism resulted in extremely low oral bioavailability (F) of CA (0.478-0.899%). 3.  CRD showed greater dose-normalized AUC in the higher dose group than that in lower dose group(s) after its administration due to saturation of its metabolism via decreased non-renal clearance (by 51.3%) and first-pass extraction. As a result, the F of CRD following 4.5 mg/kg oral CRD (21.1%) was considerably greater than those of the lower dose groups (9.10 and 13.8%). However, oral administration of CRD as DA-9701 showed linear pharmacokinetics as a result of increased AUC and F in lower-dose groups (by 182% and 78.5%, respectively) compared to those of pure CRD. The greater oral AUC of CRD for DA-9701 than for pure CRD could be due to decreased hepatic and/or GI first-pass extraction of CRD by other components in DA-9701. PMID:24417753

  19. Identification and Characterisation of New Microbial Antagonists for Biocontrol of Monilinia laxa, the Causal Agent of Brown Rot on Stone Fruit

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    Peter Jeffries

    2013-10-01

    Full Text Available Monilinia laxa is the causal agent of brown rot disease on stone fruits, and also causes blossom wilt and twig canker. The common practice used to manage this disease is through fungicide treatments. However the demand to reduce fungicide inputs has been increasing and there is a growing number of reports of M. laxa strains that are resistant to fungicides. There is an urgent need to search for an alternative strategy to control the disease. This study focused on the isolation and characterisation of biological control agents (BCAs using indigenous isolates isolated from cherries and plums collected within the UK. A total of 192 isolates were screened against two strains of M. laxa in a series of in vitro dual culture tests. From this in vitro screen, 12 isolates were selected for a subsequent in vivo screen on detached fruits, which then narrowed these isolates down to two potential BCAs. These two strains were identified as Bacillus amyloliquefaciens/subtilis (isolate B91 and Aureobasidium pullulans (isolate Y126. The capability of these two potential BCAs to grow and survive at a range of temperatures likely to be experienced under field and storage conditions was studied in order to gain knowledge for product formulation and field application. Bacillus sp. B91 was shown to be a mesophilic bacterium that could grow at 10–25 °C but suffered significant mortality at 0 and 5 °C, while A. pullulans Y126 was both mesophilic and psychrotolerant as it grew between 0–25 °C with the optimum at 20 °C. When all nutrients were removed, Y126 was able to survive for several weeks in all test temperatures (0–25 °C but showed significant mortality at 25 °C. The capability of B91 to survive at 20 and 25 °C was higher than at low temperatures (0–15 °C. In addition, the modes of action of the potential BCAs were studied. B91 was shown to produce soluble and volatile organic compounds that inhibited M. laxa, while A. pullulans Y126 did not

  20. Causality Principle

    OpenAIRE

    Chi, Do Minh

    2001-01-01

    We advance a famous principle - causality principle - but under a new view. This principle is a principium automatically leading to most fundamental laws of the nature. It is the inner origin of variation, rules evolutionary processes of things, and the answer of the quest for ultimate theories of the Universe.

  1. Evaluación a nivel de laboratorio del efecto de 7 extractos vegetales para el control de Colletotrichum sp agente causal de la antracnosis en el cultivo de tomate de árbol - Evaluación a nivel de laboratorio del efecto de 7 extractos vegetales para el control de Colletotrichum sp agente causal de la antracnosis en el cultivo de tomate de árbol

    OpenAIRE

    Christian Andrei Chacin Zambrano; Mary Lady Blanco Medina; Sonia Cecilia Sanchez; Carlos Acevedo Isidro

    2013-01-01

    Was evaluated in the laboratory the effect of seven plant extracts of Neem leaves and fruit (Azadirachta indica) leaves of lemon grass (Swinglea glutinosa), leaves of papaya (Carica papaya), Pringamosa leaves (Urtica dioica), eucalyptus leaves (Eucalyptus camaldulensis Dehn) fruits of garlic (Allium sativum L.) and fruits of pepper (Capsicum annuum) in the control of the fungus Colletotrichum sp causal agent of anthracnose in tomato crop tree (Cyphomandra betacea). The pathogen was isolated o...

  2. Functional and biophysical studies on four ceratoplatanins from the fungus Moniliophthora perniciosa, causal agent of the Witche's broom disease

    Energy Technology Data Exchange (ETDEWEB)

    Barsottini, M.; Zaparoli, G.; Garcia, O.; Pereira, G.A.G. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Oliveira, J.F.; Tiezzi, H.O.; Ambrosio, A.L.B.; Dias, S.M.G. [Laboratorio Nacional de Biociencias - LNBIO, Campinas, SP (Brazil)

    2012-07-01

    Full text: Ceratoplatanin (CP) is a secreted protein of 12.4 kDa initially identified in culture filtrates of the disease ascomycete Ceratocystis fimbriata f. sp. platani, etiological agent of the canker stain disease. CP is also the founding member of the namesake protein family, which contains fungal-secreted proteins involved in various stages of the host-fungus interaction and may act as phytotoxins or elicitors of defense response. Besides the low molecular weight, CPs have a high percentage of hydrophobic residues and share two conserved intramolecular disulfide bonds. It has been suggested that CPs have important physiological functions, including interaction with cell wall or cell membrane and manipulation of the host's defense system. Furthermore, a recent work showed that the ceratoplatanin from C. fimbriata has some degree of affinity for the saccharide 4-N-acetylglucosamine. However, its precise molecular function remains elusive. Five putative CPs have been identified in Moniliophthora perniciosa a basidiomycete fungus responsible for great economic losses in cocoa industry in the form of Witches' broom disease (WBD) , four of which had their crystal structures resolved by our group. In this work we report biophysical and functional studies on these MpCPs aiming at understanding their role and importance during the WBD progression. (author)

  3. ANÁLISE DA PERSONALIDADE DO AGENTE COMO CIRCUNSTÂNCIA JUDICIAL DE INDIVIDUALIZAÇÃO DA PENA NO DIREITO PENAL CONTEMPORÂNEO

    Directory of Open Access Journals (Sweden)

    Fernanda da Rosa Cristino

    2012-10-01

    Full Text Available Este trabalho analisa a aplicabilidade da circunstância judicial personalidade do agente como componente da individualização penal e sua compatibilidade com o Direito Penal Contemporâneo, através da exposição de seus conceitos basilares e posterior confronto com sua prática. De forma breve, é apresentada a construção dos juízos aceitos e descartados pela sistemática penal, visando provir o estudo de argumentações esclarecedoras da contradição existente. A dosimetria da pena e aspectos da individualização desta são abordados, enfatizando a personalidade, objeto da análise, por  meio de conceituações feitas pelas áreas psicológica e jurídica. Finalizando o estudo, há a exposição de decisões favoráveis e desfavoráveis relativas à matéria, como meio exemplificativo e motivacional de futuras decisões

  4. A rede de causalidade da insegurança alimentar e nutricional de comunidades quilombolas com a construção da rodovia BR-163, Pará, Brasil The causality of nutrition and food insecurity of quilombola communities with the construction of the BR-163, highway, Pará, Brazil

    OpenAIRE

    Denise Oliveira e Silva; Ana Felisa Hurtado Guerrero; Camilo Hurtado Guerrero; Luciano Medeiros de Toledo

    2008-01-01

    OBJETIVO: Trata-se da descrição de resultados baseados na elaboração de um modelo de determinação causal de forma participativa e abrangente, realizada em seis comunidades quilombolas no município de Santarém, no Estado do Pará, sobre a rede de causalidade da insegurança alimentar e nutricional com a abertura da Rodovia BR-163. MÉTODOS: O processo investigativo utilizou métodos de abordagem sócio-antropológica tendo como base o desenvolvimento de um modelo de causalidade construído por meio d...

  5. Hymenoscyphus fraxineus vs. Hymenoscyphus albidus – A comparative light microscopic study on the causal agent of European ash dieback and related foliicolous, stroma-forming species

    Science.gov (United States)

    Baral, Hans-Otto; Bemmann, Martin

    2014-01-01

    Five species of Hymenoscyphus that fruit on black stromatized parts of dead leaves of deciduous trees are presented, giving details on their morphological and ecological characteristics. Several of these species have previously been misplaced in rutstroemiaceous genera because of the presence of a substratal stroma. However, the heteropolar, scutuloid ascospores with an often hook-like lateral protrusion at the rounded apex and the ascus apical ring of the Hymenoscyphus-type represent two reliable morphological characteristics that, together with molecular data, provide clear evidence for their placement in the genus Hymenoscyphus (Helotiaceae). Among the species treated is Hymenoscyphus fraxineus (=Hymenoscyphus pseudoalbidus), the causal agent of the European ash dieback disease. Since 1992 this species started within Europe to replace the rather uncommon Hymenoscyphus albidus, which is likewise confined to leaves of Fraxinus. Hy. fraxineus has been recorded already since 1990 in Eastern Asia (Japan, Korea, northeast of China), where it had been initially misidentified as Lambertella albida (≡Hy. albidus). In these regions, it occurs as a harmless saprotroph on Fraxinus mandshurica and Fraxinus rhynchophylla, suggesting that those populations are native while the European ash dieback disease has a recent Eastern Asiatic origin. The distinctly higher genetic diversity found in Japanese Hy. fraxineus in contrast to European Hy. fraxineus supports this view. Genetic similarities between Japanese Hy. fraxineus and European Hy. albidus suggest that also Hy. albidus might be a descendant of Asian Hy. fraxineus, though having invaded Europe much earlier. However, consistent genetic deviation between European and Asian Hy. fraxineus at two nucleotide positions of the ITS region indicates that the European ash disease originates from a region different from the presently known areas in Eastern Asia. Our results underline the importance of detailed morphological studies

  6. A rede de causalidade da insegurança alimentar e nutricional de comunidades quilombolas com a construção da rodovia BR-163, Pará, Brasil The causality of nutrition and food insecurity of quilombola communities with the construction of the BR-163, highway, Pará, Brazil

    Directory of Open Access Journals (Sweden)

    Denise Oliveira e Silva

    2008-08-01

    Full Text Available OBJETIVO: Trata-se da descrição de resultados baseados na elaboração de um modelo de determinação causal de forma participativa e abrangente, realizada em seis comunidades quilombolas no município de Santarém, no Estado do Pará, sobre a rede de causalidade da insegurança alimentar e nutricional com a abertura da Rodovia BR-163. MÉTODOS: O processo investigativo utilizou métodos de abordagem sócio-antropológica tendo como base o desenvolvimento de um modelo de causalidade construído por meio da realização de grupos focais com representantes da comunidade. RESULTADOS: Os resultados do estudo demonstraram que a utilização de abordagens participativas estimula a auto-estima da comunidade e o empoderamento sobre os fatores que determinam seus problemas. O modelo causal construído revela que a insegurança alimentar e nutricional, para as comunidades, estabelece que fatores históricos relacionados à posse da terra e ao seu uso atual baseado em práticas predatórias, são os aspectos fundamentais na compreensão da rede de determinação causal da insegurança alimentar e nutricional. CONCLUSÃO: O racismo e suas nuances sociais têm contribuído para a invisibilidade social dessas comunidades nas políticas públicas brasileiras. As comunidades quilombolas se consideram em insegurança alimentar e nutricional e indicam que a abertura da Rodovia BR-163 pode ser uma ameaça ao etno-desenvolvimento sustentável na região. E referem que o desenvolvimento econômico esperado com a abertura desta rodovia, se não for realizado com base na participação da comunidade, pode aumentar a fome, a miséria e o racismo.OBJECTIVE: This work describes results based on the participative and encompassing development of a model of causal determination done in six quilombola communities of Santarém, Pará State, regarding the causality of food and nutrition insecurity with the construction of the BR-163 highway. METHODS: The research process

  7. Jogo da Minoria: um modelo baseado em agentes aplicado ao mercado financeiro Minority Game: an agent-based model applied to financial market

    Directory of Open Access Journals (Sweden)

    Antonio Fernando Crepaldi

    2012-12-01

    Full Text Available Nos últimos anos houve uma contribuição significativa dos físicos para a construção de um tipo de modelo baseado em agentes que busca reproduzir, em simulação computacional, o comportamento do mercado financeiro. Esse modelo, chamado Jogo da Minoria consiste de um grupo de agentes que vão ao mercado comprar ou vender ativos. Eles tomam decisões com base em estratégias e, por meio delas, os agentes estabelecem um intrincado jogo de competição e coordenação pela distribuição da riqueza. O modelo tem demonstrado resultados bastante ricos e surpreendentes, tanto na dinâmica do sistema como na capacidade de reproduzir características estatísticas e comportamentais do mercado financeiro. Neste artigo, são apresentadas a estrutura e a dinâmica do Jogo da Minoria, bem como as contribuições recentes relacionadas ao Jogo da Minoria denominado de Grande Canônico, que é um modelo mais bem ajustado às características do mercado financeiro e reproduz as regularidades estatísticas do preço dos ativos chamadas fatos estilizados.Over the past ten years physicists have made a significant contribution to the building of an agent-based model to reproduce the behavior of financial markets using computer simulation. This model, called the Minority Game, consists of a group of agents that buy or sell assets. They make decisions based on strategies, and through them the agents establish an intricate game of competition and coordination resulting in the distribution of wealth. The model has shown outstanding surprising results concerning both the dynamics of the system and the ability to reproduce statistical and behavior characteristics of the financial market. In this study, the structure and dynamics of the Minority Game and the recent contributions related to the Grand Canonical Minority game, a model which is better adapted to the characteristics of the financial market and reproduce the statistical regularities of asset prices (called

  8. Os agentes sociais da rede de proteção e atendimento no enfrentamento da exploração sexual comercial Social agents from protection networks in fighting commercial sexual exploitation

    OpenAIRE

    Maria de Fátima Pereira Alberto; Ana Cristina Serafim da Silva; Vanessa Cavalcante Gomes; Roberta Valesca Mota Santana; Àdria Melo Soares

    2012-01-01

    Neste artigo, apresentam-se dados de pesquisa sobre a percepção dos Agentes Sociais que atuam no enfrentamento da exploração sexual comercial de crianças e adolescentes. As entidades caracterizam-se por Organizações Governamentais, Organizações Não-Governamentais, Sistema de Justiça e Instâncias de Direitos. Compõem uma Rede de 15 instituições e foram entrevistados 31 Agentes Sociais de 12 delas. Utilizou-se um questionário composto de questões abertas e fechadas sobre: Conhecimento do Sistem...

  9. O trabalho do agente comunitário na promoção da saúde: revisão integrativa da literatura

    Directory of Open Access Journals (Sweden)

    Iara Cristina Pereira

    2013-06-01

    Full Text Available O presente artigo é uma revisão integrativa que teve como objetivo avaliar as evidências disponíveis na literatura sobre o desenvolvimento de estratégias operacionalizadas pelos agentes comunitários de saúde em prol da promoção da saúde. Para a seleção dos estudos foram usadas três bases de dados: BDTD, LILACS e SciELO. Foram encontradas 2.179 publicações, das quais 58 foram selecionadas para análise. Os resultados foram sistematizados em três categorias empíricas: A promoção da saúde: desafios na reorientação do modelo assistencial, A prática educativa no cotidiano de trabalho dos ACS e A formação profissional na perspectiva da Atenção Primária em Saúde. Concluiu-se que a construção de um modelo assistencial baseado na promoção da saúde requer a incorporação de novas práticas formativas, assistenciais e institucionais.

  10. Os agentes sociais da rede de proteção e atendimento no enfrentamento da exploração sexual comercial Social agents from protection networks in fighting commercial sexual exploitation

    Directory of Open Access Journals (Sweden)

    Maria de Fátima Pereira Alberto

    2012-01-01

    Full Text Available Neste artigo, apresentam-se dados de pesquisa sobre a percepção dos Agentes Sociais que atuam no enfrentamento da exploração sexual comercial de crianças e adolescentes. As entidades caracterizam-se por Organizações Governamentais, Organizações Não-Governamentais, Sistema de Justiça e Instâncias de Direitos. Compõem uma Rede de 15 instituições e foram entrevistados 31 Agentes Sociais de 12 delas. Utilizou-se um questionário composto de questões abertas e fechadas sobre: Conhecimento do Sistema de Proteção; Percepção da ESCCA; Formas de Enfrentamento da ESCCA; Procedimentos e Medidas em casos de suspeitas, identificações, denúncias e notificações. A maioria dos Agentes Sociais tem conhecimento do papel da instituição, embora alguns desconheçam parte da Legislação e as formas de se efetivar na prática o papel daquelas e a articulação interinstitucional.This article shows the data collected in a research regarding the perception of Social Agents who act in fighting children and adolescents' commercial sexual exploitation. The networking is composed by Governmental Organizations, Non-governmental Organizations, Justice System and Human Rights entities. They compose a network of 15 institutions, and 31 Social Agents who belonged to 12 of them were interviewed. It was used a questionnaire composed by open and closed questions about protection systems knowledge; perception of children and adolescents' commercial sexual exploitation; forms of fighting children and adolescents' commercial sexual exploitation; procedures and actions in case of suspicion, identification, denunciation and notification. Most of the Social Agents who make part of the network know the role of the institution where they work, although some of them do not know part of the Legislation which deals with this problematic and they also do not know the forms to effectuate in practice the purpose of the Legislation and its inter

  11. Especificação normativa de agentes institucionais e da interacção entre agentes

    OpenAIRE

    Pacheco, Olga

    2001-01-01

    O trabalho apresentado nesta dissertação teve por objectivo essencial, contribuir para o estudo formal de conceitos e de modelos adequados para a especificação normativa de entidades colectivas organizadas e que permitissem uma análise rigorosa de tais entidades. Tendo por base o conceito jurídico de pessoa colectiva e as relações jurídicas de mandato e de representação, introduzem-se os conceitos de papel, acção num papel, representação entre agentes, contrato e agente instit...

  12. Acción inhibitoria de una cepa de Zymomonas mobilis mobilis aislada de caña de azúcar sobre Xanthomonas citri subsp. citri, agente causal de la cancrosis de los cítricos Inhibition of Xanthomonas citri subsp. citri, causal agent of citrus canker, by a strain of Zymomonas mobilis mobilis isolated from sugarcane

    Directory of Open Access Journals (Sweden)

    María E. Romero

    2008-06-01

    a wide range of microorganisms pathogenic to man, animals, and plants. An important problem to solve with antimicrobial treatments is the development of resistance in these microorganisms, including phytopathogenic bacteria, to the currently used active ingredients. In this study, antagonism tests with cells (cross-streaking and cell-free culture supernatants (CCS (agar diffusion test from Zm cultures, isolated from sugarcane juice in Tucumán, were carried out, measuring activity against Xanthomonas citri subsp. citri (Xcc, the causal agent of citrus canker. Xcc isolates sensitive (Xc and resistant (Xcr to copper pesticides were included in these tests. Results showed that indicator bacteria were completely inhibited by cells of Zm, which had a bactericide effect. Both Xc and Xcr were sensitive to the CCS in the agar diffusion method. Previous studies had revealed the deleterious effects of metabolites from Zm on cell membranes of E. coli AB1133, inhibiting the respiration of the bacteria inmediately after CCS addition. On the basis of these results, the effects of CCS on Xcc respiration were studied, verifyng a similar response. This would indicate that the site of action of these antimicrobial compounds is also located at the cell membrane of the bacteria under study. Based on these results, additional studies are suggested to evaluate Zm-derived products on the control of diseases that affect economically important crops, such as citrus canker.

  13. Agentes antitumorais inibidores da angiogênese: modelos farmacofóricos para inibidores da integrina anb3 Angiogenesis inhibitors antitumor agents: pharmacophore models to anb3 antagonists

    Directory of Open Access Journals (Sweden)

    Thais Horta Álvares da Silva

    2007-03-01

    Full Text Available O câncer é, atualmente, uma das principais causas de morte no mundo. A angiogênese, formação de novos vasos capilares a partir de células endoteliais, é essencial para vários processos fisiopatológicos, tais como o desenvolvimento e a disseminação dos tumores. As integrinas são uma família de receptores de superfície que estão envolvidos na angiogênese, na qual a integrina anb3 exerce papel importante. Os antagonistas da integrina anb3 têm efeitos diretos na prevenção do crescimento, angiogênese e metástase tumorais. A avaliação in vitro frente à integrina anb3 de coleções de ciclopeptídeos levou a compostos muito ativos e seletivos. Antagonistas não-peptídicos da integrina anb3 também foram planejados e sintetizados. A partir da determinação da estrutura tridimensional da integrina anb3 complexada com um inibidor, tornou-se possível o planejamento racional de ligantes com alta afinidade. Além disto, estes estudos permitiram a validação e o refinamento de modelo farmacofórico para os inibidores da integrina anb3.Cancer is one of the leading causes of death. Angiogenesis, the growth of new blood vessels, is essential for tumor development and spreading. Integrins are a family of surface receptors that are involved in angiogenesis. The anb3 integrin plays an important role in tumor angiogenesis. anb3 inhibitors have direct effects to prevent tumor metastases, growth and angiogenesis. In vitro screening of cyclic peptide libraries led to highly active and anb3-selective compounds. Non-peptidic anb3 antagonists were also designed and synthesized. The crystal structure of the anb3 integrin in complex with RGD ligant allowed structure-based rational design of ligands and validation of pharmacophore model to anb3 antagonists.

  14. Atividade in vitro do extrato de própolis contra agentes bacterianos da mastite bovina In vitro activity of propolis extract against bovine mastitis bacterial agents

    Directory of Open Access Journals (Sweden)

    Andrea Pinto Loguercio

    2006-02-01

    Full Text Available Este trabalho foi desenvolvido com o objetivo de avaliar a atividade in vitro do extrato alcoólico de própolis, contra agentes da mastite bovina, comparando-o aos principais antimicrobianos utilizados no tratamento convencional. Foram utilizados 36 isolados coagulase-positivos de Staphylococcus sp. e 27 isolados de Streptococcus sp.; 94,4% dos Staphylococcus sp. e 85,2% dos Streptococcus sp. foram susceptíveis ao extrato de própolis.The present study aimed to determine the in vitro activity of propolis extract, comparing it to the most common antibacterial drugs against bovine mastitis bacterial agents. Thirty-six isolates of coagulase-positive Staphylococcus sp. and twenty-seven of Streptococcus sp. were analyzed. Coagulase-positive Staphylococcus (94.4% and Streptococcus sp. (85.2% showed susceptibility to propolis extract.

  15. Principais características da raiz de cenoura na perspectiva de agentes da cadeia produtiva Main carrot root attributes based on stake holders perceptions

    Directory of Open Access Journals (Sweden)

    Silvia S Onoyama

    2011-09-01

    Full Text Available Procurou-se verificar quais são as características mais importantes da raiz de cenoura sob a ótica dos agentes da cadeia produtiva de cenoura. Para tanto, foram realizadas visitas e entrevistas com produtores, empresas de semente, vendedores de insumos, lavadores, processadores, atacadistas e gerentes de supermercados, comparando-se esses resultados com os da pesquisa de percepção de consumidores de supermercados do Distrito Federal. Em ambos os casos, utilizou-se questionário estruturado com perguntas fechadas nas quais os entrevistados classificaram os atributos segundo notas que variaram de 1 (nenhuma importância a 5 (muito importante. Para verificar a ordenação de importância dos atributos e os contrastes das médias, utilizou-se o método estatístico de análise de dados categóricos. O resultado da pesquisa indicou que os consumidores estão preocupados com valores nutricionais, textura, cor externa e sabor da cenoura. Já os demais agentes da cadeia atentaram mais para as características relacionadas com a padronização, com a coloração externa e com o ombro verde. Foram detectadas diferenças de percepção entre os agentes da cadeia, em especial dos consumidores, para os quais foram observadas diferenças nas respostas em função do gênero, idade, grau de escolaridade, estado civil e localização do supermercado. Estes resultados são muito importantes para o direcionamento de projetos de pesquisa com cenoura, que precisa atender as exigências tanto do setor produtivo quanto dos consumidores.The present investigation aimed at elucidating the carrot attributes which stake holders view as the most important. A research was carried out with carrot growers, seed companies, supplier salespersons, washers, food processors, wholesalers and supermarket managers and was compared to the perception of consumers from supermarkets located in the Federal District of Brazil. Data sets were collected through structured interviews

  16. Use of the montmorillonite as crosslink agents for chitosan; Uso da montmorilonita como agente de reticulacao para a quitosana

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Rossemberg C.; Lima, Rosemary S. Cunha; Braga, Carla R. Costa [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Programa de Pos-graduacao em Ciencia e Engenharia de Materiais; Fook, Marcus V. Lia; Silva, Suedina M. Lima [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia de Materiais

    2009-07-01

    The montmorillonite (the main constituent of bentonite) has been the most commonly used inorganic load in the formation of nanocomposites chitosan / layered silicate. To evaluate its effect as an agent for the reticulation of chitosan, a sodium montmorillonite, Cloisite Na{sup +}, supplied by Southern Clay Products, Texas, USA, was used. For the reticulation of chitosan dispersions of chitosan / Cloisite Na{sup +} were prepared in different proportions and the obtained films characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TG). The results indicated that the Cloisite Na{sup +} was for efficient and the reticulation of the chitosan and can be used in place of sulfuric acid, which is one of the most common reticulants for chitosan. (author)

  17. Opening Pousada da Serra da Estrela in Covilhã: A two-way impact analysis - interacting with private agents

    OpenAIRE

    Cristina, Patrícia Alexandra de Brito

    2014-01-01

    In an era where tourism represents almost 16% of Portugal’s GDP, tourism management becomes a very relevant thematic. Tourists are increasingly opting for more tailored experiences, and in order to satisfy these needs it must be required to know how to manage a destination. This work is based on research into networking between private agents related to tourism activities and its contribution to destination development, offering thereby a complementary literature review in social networks....

  18. A Bolsa de Valores Sociais enquanto agente de renovação da economia social

    OpenAIRE

    Meira, Deolinda Aparício

    2013-01-01

    Este artigo visa contribuir para o conhecimento da Bolsa de Valores Sociais (BVS), recentemente criada em Portugal, cuja finalidade foi, primacialmente, a de permitir a obtenção de meios de financiamento às entidades da Economia Social que se dediquem a projectos nas áreas da educação e do empreendedorismo. Reflectir-se-á sobre a qualificação jurídica dos vários tipos de entidades cotadas na BVS, sobre o conceito de investidor social e a protecção de que este beneficia, com as consequentes ex...

  19. Causal reasoning in physics

    CERN Document Server

    Frisch, Mathias

    2014-01-01

    Much has been written on the role of causal notions and causal reasoning in the so-called 'special sciences' and in common sense. But does causal reasoning also play a role in physics? Mathias Frisch argues that, contrary to what influential philosophical arguments purport to show, the answer is yes. Time-asymmetric causal structures are as integral a part of the representational toolkit of physics as a theory's dynamical equations. Frisch develops his argument partly through a critique of anti-causal arguments and partly through a detailed examination of actual examples of causal notions in physics, including causal principles invoked in linear response theory and in representations of radiation phenomena. Offering a new perspective on the nature of scientific theories and causal reasoning, this book will be of interest to professional philosophers, graduate students, and anyone interested in the role of causal thinking in science.

  20. Glucanases and Chitinases as Causal Agents in the Protection of Acacia Extrafloral Nectar from Infestation by Phytopathogens1[W][OA

    Science.gov (United States)

    González-Teuber, Marcia; Pozo, María J.; Muck, Alexander; Svatos, Ales; Adame-Álvarez, Rosa M.; Heil, Martin

    2010-01-01

    Nectars are rich in primary metabolites and attract mutualistic animals, which serve as pollinators or as an indirect defense against herbivores. Their chemical composition makes nectars prone to microbial infestation. As protective strategy, floral nectar of ornamental tobacco (Nicotiana langsdorffii × Nicotiana sanderae) contains “nectarins,” proteins producing reactive oxygen species such as hydrogen peroxide. By contrast, pathogenesis-related (PR) proteins were detected in Acacia extrafloral nectar (EFN), which is secreted in the context of defensive ant-plant mutualisms. We investigated whether these PR proteins protect EFN from phytopathogens. Five sympatric species (Acacia cornigera, A. hindsii, A. collinsii, A. farnesiana, and Prosopis juliflora) were compared that differ in their ant-plant mutualism. EFN of myrmecophytes, which are obligate ant-plants that secrete EFN constitutively to nourish specialized ant inhabitants, significantly inhibited the growth of four out of six tested phytopathogenic microorganisms. By contrast, EFN of nonmyrmecophytes, which is secreted only transiently in response to herbivory, did not exhibit a detectable inhibitory activity. Combining two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis with nanoflow liquid chromatography-tandem mass spectrometry analysis confirmed that PR proteins represented over 90% of all proteins in myrmecophyte EFN. The inhibition of microbial growth was exerted by the protein fraction, but not the small metabolites of this EFN, and disappeared when nectar was heated. In-gel assays demonstrated the activity of acidic and basic chitinases in all EFNs, whereas glucanases were detected only in EFN of myrmecophytes. Our results demonstrate that PR proteins causally underlie the protection of Acacia EFN from microorganisms and that acidic and basic glucanases likely represent the most important prerequisite in this defensive function. PMID:20023149

  1. Regression to Causality

    DEFF Research Database (Denmark)

    Bordacconi, Mats Joe; Larsen, Martin Vinæs

    2014-01-01

    Humans are fundamentally primed for making causal attributions based on correlations. This implies that researchers must be careful to present their results in a manner that inhibits unwarranted causal attribution. In this paper, we present the results of an experiment that suggests regression...... models should note carefully both their models’ identifying assumptions and which causal attributions can safely be concluded from their analysis....

  2. The Equation of Causality

    OpenAIRE

    Chi, Do Minh

    1999-01-01

    We research the natural causality of the Universe. We find that the equation of causality provides very good results on physics. That is our first endeavour and success in describing a quantitative expression of the law of causality. Hence, our theoretical point suggests ideas to build other laws including the law of the Universe's evolution.

  3. Evaluación a nivel de laboratorio del efecto de 7 extractos vegetales para el control de Colletotrichum sp agente causal de la antracnosis en el cultivo de tomate de árbol - Evaluación a nivel de laboratorio del efecto de 7 extractos vegetales para el control de Colletotrichum sp agente causal de la antracnosis en el cultivo de tomate de árbol

    Directory of Open Access Journals (Sweden)

    Christian Andrei Chacin Zambrano

    2013-08-01

    Full Text Available Was evaluated in the laboratory the effect of seven plant extracts of Neem leaves and fruit (Azadirachta indica leaves of lemon grass (Swinglea glutinosa, leaves of papaya (Carica papaya, Pringamosa leaves (Urtica dioica, eucalyptus leaves (Eucalyptus camaldulensis Dehn fruits of garlic (Allium sativum L. and fruits of pepper (Capsicum annuum in the control of the fungus Colletotrichum sp causal agent of anthracnose in tomato crop tree (Cyphomandra betacea. The pathogen was isolated on PDA medium from tomato fruit tree, the extracts were obtained taking into account the process by (Marin, et. Al 2007, which consists of chopping and blending plant material deposited in plastic bucket, add water ratio 2.5:1 (water: sample processed, vol.: w, subjecting to fermentation for 24 hours. The produto was filtered using sterile gauze and package them for further evaluation. The concentrations of the treatments that worked were 25, 50, 75 and 100% of the infectious agent, determining the degree of inhibition of the pathogen in Petri dishes. The best results were obtained with the application of eucalyptus leaves, since its effect was 100% at all concentrations, without neglecting the fruits of the Neem and garlic with inhibition percentages of 75 and 60% respectively, had a behavior directly proportional to the concentrations used, since the greater the amount of extract the inhibitory effect was better in this case 75% and 100%.

  4. Predictors for dioxin accumulation in residents living in Da Nang and Bien Hoa, Vietnam, many years after Agent Orange use.

    Science.gov (United States)

    Pham, Diem T; Nguyen, Hang M; Boivin, Thomas G; Zajacova, Anna; Huzurbazar, Snehalata V; Bergman, Harold L

    2015-01-01

    Agent Orange (AO) was the main defoliant used by the US in Vietnam from 1961 to 1971; AO was contaminated with dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin, or TCDD). Three major dioxin “hot spots” remain from previous AO storage and use at former US bases at Bien Hoa, Da Nang, and Phu Cat, posing potential health risks for Vietnamese living on or near these hot spots. We evaluated potential risk factors contributing to serum TCDD levels in Vietnamese residents at and near contaminated sites in Da Nang and Bien Hoa, Vietnam. We used multiple linear regression to analyze possible associations of blood dioxin concentrations with demographic, socioeconomic, lifestyle, and dietary risk factors for residents living on or near these hot spots. For the Da Nang study, fish farming on the site, living on property flooded from monsoon rains, and age were among the factors showing significant positive associations with serum TCDD concentrations. For the Bien Hoa study, fish farmers working at this site and their immediate family members had significantly higher serum TCDD concentrations. Our results suggest that water-related activities, especially fish-farming, at the hot spots increased the risk of exposure to dioxin. PMID:25463251

  5. Brominated and radioiodinated derivatives of methylphenidate (MP): Potential imaging agents for the dopamine (DA) transporter

    Energy Technology Data Exchange (ETDEWEB)

    Pan, D.; Gatley, S.J.; Dewey, S.L. [Brookhaven National Lab., Upton, NY (United States)] [and others

    1994-05-01

    MP (Ritalin) is a psychomotor stimulant used in the treatment of attention-deficit hyperactivity disorder. The therapeutic properties of MP are thought to be mediated by its binding to a site on the DA transporter, resulting in inhibition of DA reuptake and enhanced levels of synaptic dopamine. MP also inhibits reuptake of norepinephrine (NE) in vitro. MP has two chiral centers, but its pharmacological activity is believed due solely to the d-threo isomer. We have found that d,l-threo-C-11 MP has favorable properties for PET studies, and therefore examined the effects of incorporating halogen atoms into the phenyl ring of MP, with a view to preparing C-11 and I-123 MP analogs as potential PET/SPECT tracers. We synthesized the 2-, 3- and 4-bromo MP analogs from the corresponding bromophenylacetonitriles by modification of the original synthesis of MP. In in vitro binding assays all three d,l-threo bromo compounds had higher affinities than MP for DA transporter sites labeled with tritiated WIN 35,428 (3->4-, 2->MP). They also showed high activity with NE reuptake sites labeled with tritiated nisoxetine. They were active in vivo as demonstrated by inhibition of heart uptake of tritiated NE in the mouse, and elevation of striatal extracellular DA (microdialysis) and stimulation of locomotor activity in the rat.

  6. Effect of carbon and nitrogen sources on growth and biological efficacy of Pseudomonas fluorescens and Bacillus subtilis against Rhizoctonia solani, the causal agent of bean damping-off.

    Science.gov (United States)

    Peighamy-Ashnaei, S; Sharifi-Tehrani, A; Ahmadzadeh, M; Behboudi, K

    2007-01-01

    One of the most important environmental factors that regulate the growth and antagonistic efficacy of biocontrol agents is the medium. The aim of this paper was to find the nitrogen and carbon sources that provide maximum biomass production of strains P-5 and P-6 (Pseudomonas fluorescens), B-3 and B-16 (Bacillus subtilis) and minimum cost of media, whilst maintaining biocontrol efficacy. All of the strains were grown in seven liquid media (pH=6.9) including: sucrose + yeast extract, molasses of sugar beet + yeast extract in 2:1 and 1:1 w/w ratios, molasses of sugar beet + urea, nutrient broth, molasses and malt extract, at an initial inoculation of 1 x 10(5) CFU ml(-1). Cells from over night cultures used to inoculate soil at 1 x 10(9) CFU cm(-3) soil. At the same time, fungal inoculum (infected millet seed with Rhizoctonia solani) was added to soil at the rate of 2 g kg(-1) soil. Results indicated that growth of P-6, B-3 and B-16 in molasses + yeast extract (1:1 w/w) medium was significantly higher than in the other media. Molasses + yeast extract (1:1 and 2:1 w/w) media supported rapid growth and high cell yields in P-5. In greenhouse condition, results indicated that the influence of the media on the biocontrol efficacy of P-5, P-6, B-3 and B-16 was the same and Pseudomonas fluorescens P-5 in molasses and malt extract media reduced the severity of disease up to 72.8 percent. On the other hand, there were observed significant differences on bean growth after one month in greenhouse. P-5 in molasses + yeast extract (1:1 w/w) medium had the most effects on bean growth promotion. In this study molasses media showed good yield efficacy in all of the strains. The high sucrose concentration in molasses justifies the high biomass in all of the strains. Also, the low cost of molasses allows its concentration to be increased in media. On the other hand, yeast extract was the best organic nitrogen source for antagonist bacteria but it is expensive for an industrial process

  7. Biocontrol traits and antagonistic potential of Bacillus amyloliquefaciens strain NJZJSB3 against Sclerotinia sclerotiorum, a causal agent of canola stem rot.

    Science.gov (United States)

    Wu, Yuncheng; Yuan, Jun; Raza, Waseem; Shen, Qirong; Huang, Qiwei

    2014-10-01

    Bacillus amyloliquefaciens strain NJZJSB3 has shown antagonism of several phytopathogens in vitro, especially Sclerotinia sclerotiorum. Both the broth culture and cell suspension of strain NJZJSB3 could completely protect the detached leaves of canola (Brassica napus) from S. sclerotiorum infection. In pot experiments, the application of strain NJZJSB3 cell suspension (10(8) CFU/ml) decreased the disease incidence by 83.3%, a result similar to commercially available fungicide (Dimetachlone). In order to investigate the potential biocontrol mechanisms of strain NJZJSB3, the nonvolatile antifungal compounds it produces were identified as iturin homologs using HPLC-ESI-MS. Antifungal volatile organic compounds were identified by gas chromatography-mass spectrometry. The detected volatiles toluene, phenol, and benzothiazole showed antifungal effects against S. sclerotiorum in chemical control experiments. Strain NJZJSB3 also produced biofilm, siderophores and cell-wall-degrading enzymes (protease and β-1,3-glucanase). These results suggest that strain NJZJSB3 can be a tremendous potential agent for the biological control of sclerotinia stem rot. PMID:24861342

  8. The effect of locust bean gum (LBG)-based edible coatings carrying biocontrol yeasts against Penicillium digitatum and Penicillium italicum causal agents of postharvest decay of mandarin fruit.

    Science.gov (United States)

    Parafati, Lucia; Vitale, Alessandro; Restuccia, Cristina; Cirvilleri, Gabriella

    2016-09-01

    Strains belonging to Wickerhamomyces anomalus, Metschnikowia pulcherrima and Aureobasidium pullulans species were tested in vitro as biocontrol agents (BCAs) against the post-harvest pathogenic molds Penicillium digitatum and Penicillium italicum. Moreover, studies aimed at screening the antifungal activity of selected yeast strains in vivo conditions against P. digitatum and P. italicum, and investigated the efficacy of a polysaccharidic matrix, locust bean gum (LBG), enriched with the tested BCAs, in controlling postharvest decays in artificially inoculated mandarins. The population dynamics of BCAs on wounds and the magnitude of peroxidase (POD) and superoxide dismutase (SOD) in fruit tissues were also investigated after treatments of mandarins with antagonistic yeasts. W. anomalus BS91, M. pulcherrima MPR3 and A. pullulans PI1 provided excellent control of postharvest decays caused by P. digitatum and P. italicum on mandarins, both when the yeasts were used alone and in combination with LBG, which enhanced the yeast cell viability over time. Finally, the increased activity of POD and lower decrease in SOD activity in response to BCAs application in mandarin fruits confirmed their involvement in the biocontrol mechanism. PMID:27217363

  9. Biocontrol of Botrytis allii Munn the Causal Agent of Neck Rot, the Post Harvest Disease in Onion, by use of a New Iranian Isolate of Streptomyces

    Directory of Open Access Journals (Sweden)

    M. Jorjandi

    2009-01-01

    Full Text Available Problem statement: Soil actinomycetes particularly Streptomyces spp. showed antagonistic activity against wide range of plant pathogens. In the recent decades they have attracted high interests as biocontrol agents. Onion neck rot or gray mold caused by Botrytis allii have imposed economic post harvest damages to onion bulbs and decreased its storage durability and market value. Approach: To investigate for biocontrol means against the pathogen, antagonistic activity of 50 isolates of soil Actinomycetes were assayed through agar disk method and dual culture bioassays. Active isolates were exposed to chloroform for detection of antibiotic. Minimum Inhibitory Concentration (MIC value and solubility of active crude extract in organic solvents were determined for Streptomyces isolate No. 347 which showed a unique and stable property of inhibiting Botrytis allii. To investigate the antagonistic effect of Streptomyces isolate No. 347 on control of onion gray mold, 4 different treatments were tested by means of Tukey HSD test. Results: From the tested isolates, 13 showed anti gray mold activities. Exposure of active isolates to chloroform revealed that Streptomyces isolates No. 347, 263 and 350 retained their antifungal activities. The active metabolite(s of Streptomyces isolate No. 347 was polar, soluble in H2O but insoluble in chloroform and methanol. MIC of the crude was determined as 0.05 mg mL-1 against B. allii. Stability of the active crude in distilled water at room temperature (12-30°C was about 6 months. Statistical studies indicated that Streptomyces isolates No. 347 can decrease losses of neck rot with significant level (pConclusion: The future goals include investigation of the antifungal genes in active isolates as candidates for genetic engineering of onion for increased tolerance against B. allii.

  10. A exaustão profissional nos agentes da polícia de segurança pública do concelho de Viseu

    OpenAIRE

    Machado, Cátia Solange Araújo

    2011-01-01

    O presente estudo é transversal e evidencia um desenho descritivo, este pretendeu identificar e caracterizar a incidência do burnout em agentes da Polícia da Segurança Pública (PSP). As condições físicas, ambientais e psicológicas do trabalho remetem para uma dimensão da saúde psicológica. Os agentes da PSP estão expostos a estas condições, o que poderá traduzir relações entre os factores de stress no trabalho e a exaustão profissional (burnout), dado que esta é considerada uma resposta in...

  11. Pyrenophora bromi, causal agent of brownspot of bromegrass, expresses a gene encoding a protein with homology and similar activity to Ptr ToxB, a host-selective toxin of wheat.

    Science.gov (United States)

    Andrie, Rachael M; Ciuffetti, Lynda M

    2011-03-01

    Ptr ToxB, encoded by ToxB, is one of multiple host-selective toxins (HST) produced by the wheat pathogen Pyrenophora tritici-repentis. Homologs of ToxB are found in several ascomycetes, including sister species Pyrenophora bromi, causal agent of brownspot of bromegrass. Due to the close evolutionary relatedness of P. tritici-repentis and P. bromi and that of their grass hosts, we hypothesized that homologs of ToxB in P. bromi may act as HST in the disease interaction between P. bromi and bromegrass. A representative set of transcriptionally active P. bromi ToxB genes were heterologously expressed in Pichia pastoris and the resultant proteins tested for their ability to act as HST on bromegrass. The tested Pyrenophora bromi ToxB (Pb ToxB) proteins were not toxic to bromegrass; thus, Pb ToxB does not appear to function as an HST in the P. bromi-bromegrass interaction. Instead, we revealed that the Pb ToxB proteins can be toxic to Ptr ToxB-sensitive wheat, at levels similar to Ptr ToxB, and the corresponding P. bromi ToxB genes are expressed in P. bromi-inoculated wheat. Our data suggest that P. bromi possesses the potential to become a wheat pathogen and highlights the importance of investigating the interaction between P. bromi and wheat. PMID:21091157

  12. Endophytic bacteria from Piper tuberculatum Jacq.: isolation, molecular characterization, and in vitro screening for the control of Fusarium solani f. sp piperis, the causal agent of root rot disease in black pepper (Piper nigrum L.).

    Science.gov (United States)

    Nascimento, S B; Lima, A M; Borges, B N; de Souza, C R B

    2015-01-01

    Endophytic bacteria have been found to colonize internal tissues in many different plants, where they can have several beneficial effects, including defense against pathogens. In this study, we aimed to identify endophytic bacteria associated with roots of the tropical piperaceae Piper tuberculatum, which is known for its resistance to infection by Fusarium solani f. sp piperis, the causal agent of black pepper (Piper nigrum) root rot disease in the Amazon region. Based on 16S rRNA gene sequence analysis, we isolated endophytes belonging to 13 genera: Bacillus, Paenibacillus, Pseudomonas, Enterobacter, Rhizobium, Sinorhizobium, Agrobacterium, Ralstonia, Serratia, Cupriavidus, Mitsuaria, Pantoea, and Staphylococcus. The results showed that 56.52% of isolates were associated with the phylum Proteobacteria, which comprised α, β, and γ classes. Other bacteria were related to the phylum Firmicutes, including Bacillus, which was the most abundant genus among all isolates. Antagonistic assays revealed that Pt12 and Pt13 isolates, identified as Pseudomonas putida and Pseudomonas sp, respectively, were able to inhibit F. solani f. sp piperis growth in vitro. We describe, for the first time, the molecular identification of 23 endophytic bacteria from P. tuberculatum, among which two Pseudomonas species have the potential to control the pathogen responsible for root rot disease in black pepper in the Amazon region. PMID:26214435

  13. Times and Causality

    OpenAIRE

    Davidson, Russell

    2013-01-01

    The understanding of causal chains and mechanisms is an essential part of any scientific activity that aims at better explanation of its subject matter, and better understanding of it. While any account of causality requires that a cause should precede its effect, accounts of causality inphysics are complicated by the fact that the role of time in current theoretical physics has evolved very substantially throughout the twentieth century. In this article, I review the status of time and causa...

  14. Viscous causal cosmologies

    International Nuclear Information System (INIS)

    A set of spatially homogeneous and isotropic cosmological geometries generated by a class of non-perfect is investigated fluids. The irreversibility if this system is studied in the context of causal thermodynamics which provides a useful mechanism to conform to the non-violation of the causal principle. (author)

  15. Causality in demand

    DEFF Research Database (Denmark)

    Nielsen, Max; Jensen, Frank; Setälä, Jari;

    2011-01-01

    to fish demand. On the German market for farmed trout and substitutes, it is found that supply sources, i.e. aquaculture and fishery, are not the only determinant of causality. Storing, tightness of management and aggregation level of integrated markets might also be important. The methodological......This article focuses on causality in demand. A methodology where causality is imposed and tested within an empirical co-integrated demand model, not prespecified, is suggested. The methodology allows different causality of different products within the same demand system. The methodology is applied...... implication is that more explicit focus on causality in demand analyses provides improved information. The results suggest that frozen trout forms part of a large European whitefish market, where prices of fresh trout are formed on a relatively separate market. Redfish is a substitute on both markets. The...

  16. Causality and Composite Structure

    CERN Document Server

    Joglekar, Satish D

    2007-01-01

    We study the question of whether a composite structure of elementary particles, with a length scale $1/\\Lambda$, can leave observable effects of non-locality and causality violation at higher energies (but $\\lesssim \\Lambda$). We formulate a model-independent approach based on Bogoliubov-Shirkov formulation of causality. We analyze the relation between the fundamental theory (of finer constituents) and the derived theory (of composite particles). We assume that the fundamental theory is causal and formulate a condition which must be fulfilled for the derived theory to be causal. We analyze the condition and exhibit possibilities which fulfil and which violate the condition. We make comments on how causality violating amplitudes can arise.

  17. Agency, time and causality

    Directory of Open Access Journals (Sweden)

    Thomas eWidlok

    2014-11-01

    Full Text Available Cognitive Scientists interested in causal cognition increasingly search for evidence from non-WEIRD people but find only very few cross-cultural studies that specifically target causal cognition. This article suggests how information about causality can be retrieved from ethnographic monographs, specifically from ethnographies that discuss agency and concepts of time. Many apparent cultural differences with regard to causal cognition dissolve when cultural extensions of agency and personhood to non-humans are taken into account. At the same time considerable variability remains when we include notions of time, linearity and sequence. The article focuses on ethnographic case studies from Africa but provides a more general perspective on the role of ethnography in research on the diversity and universality of causal cognition.

  18. Community health agent: a literature review Agente comunitario de salud: una revisión de literatura O agente comunitário de saúde: uma revisão da literatura

    Directory of Open Access Journals (Sweden)

    Ana Cláudia Garabeli Cavalli Kluthcovsky

    2006-12-01

    Full Text Available Study of the review literature regarding brazilian Community Health Agent. The methodology was descriptive and exploratory study, using the LILACS database (1982 to march/2005 and MEDLINE (1966 to 2005. The analysis resulted 153 publications, from which 97 had been excluded. About type of production, of the 56 references (100%, 53,6% were books, 32,1% periodic articles, 7,1% Master's Theses and remains 7,2%, doctoral dissertations and specialization monographs. It was observed that 59% of the references had been enclosed in the database in 2000. Considering only periodic articles, specialization monographs, Master's Theses and doctoral dissertations, an amount of 26 studies, the experimental design predominated (73%, being the objectives most frequent: characterization of the agents and their functions, process work and results. The data suggest increasing interest on the subject, however, these workers still consist a population little studied.Estudio de literatura de revisión sobre Agente Comunitario de Salud brasileiro. La metodología era estudio descriptivo y exploratório, en base de datos LILACS (1982 a 2005 y MEDLINE (1966 a 2005. El análisis resultó 153 publicaciones, 97 excluidos. De las 56 referencias (100%, 53,6% eran los libros, 32,1% artículos de periódicos, 7,1% eran disertaciones de maestría y del resto 7,2%, las tesis de doctorado y monografías de especialización. El 59% de las referencias habían sido incluidos en la base de datos en 2000. Considerando los artículos periódicos, las monografías de especialización, dissertaciones de maestría y tesis de doctorado (26 estudios, el diseño experimental predominó (73%, siendo los objetivos más frecuentes: caracterización de los agentes y de sus funciones, evaluaciónes del proceso y de los resultados del trabajo. Los datos sugieren interés de aumento en el tema, estos trabajadores todavía consisten una población poco estudiada.Este é um estudo de revisão da

  19. Dynamics and causality constraints

    International Nuclear Information System (INIS)

    The physical meaning and the geometrical interpretation of causality implementation in classical field theories are discussed. Causality in field theory are kinematical constraints dynamically implemented via solutions of the field equation, but in a limit of zero-distance from the field sources part of these constraints carries a dynamical content that explains old problems of classical electrodynamics away with deep implications to the nature of physicals interactions. (author)

  20. Dynamics and causality constraints

    CERN Document Server

    De Souza, M M

    2000-01-01

    The physical meaning and the geometrical interpretation of causality implementation in classical field theories are discussed. Local causality are kinematical constraints dynamically implemented via solutions of the field equations, but in a limit of zero-distance from the field sources part of these constraints carries a dynamical content that explains old problems of classical electrodynamics away and implies on deep implications to the nature of physical interactions.

  1. Almanaque da Dengue: leituras e narrativas de Agentes Comunitários de Saúde Almanaque de Dengue: lecturas y narraciones de Agentes Comunitarios de Salud Dengue Almanac: readings and narratives of Community Health Agents

    Directory of Open Access Journals (Sweden)

    Helena Maria Scherlowski Leal David

    2012-12-01

    Full Text Available Apresenta-se um estudo de leitura e apropriação como metodologia de aproximação ao universo narrativo de Agentes Comunitários de Saúde (ACS, usando um dispositivo de informação e comunicação - o Almanaque da Dengue (AD. O objetivo foi o de perceber as formas de construção e apropriação de saberes sobre dengue e saúde por parte dos ACS, além de avaliar a serventia do AD como um dispositivo info-comunicacional. Foram realizadas oficinas com agentes do Rio de Janeiro, com vistas à desconstrução e leitura relacional do AD. A análise das narrativas gerou três categorias temáticas: abundância informacional nos ciclos epidêmicos; culpabilização da vítima; contradições e ambiguidades no trabalho dos ACS como mediadores. O AD mostrou-se um instrumento útil na discussão e apropriação de informações sobre a saúde, devido ao caráter textual relacional e não linear dos seus conteúdos, e ao seu formato interativo e não impositivo de formulações sobre a dengue e saúde.Presentase un estudio de lectura y apropiación como método de acercamiento al universo narrativo de los agentes comunitarios de salud (ACS, utilizando un dispositivo de información y comunicación, el Almanaque de Dengue (AD. Objetivó-se ampliar la comprensión acerca de las formas de construcción y apropiación de conocimientos sobre dengue y salud, y evaluar el Almanac como un dispositivo info-comunicacional. La metodología cualitativa se desarrolló por medio de talleres con ACS de Río de Janeiro, para la deconstrucción y lectura relacional del AD. Los resultados se clasificaron en tres temas: la abundancia de información en ciclos epidémicos, culpa de la víctima, las contradicciones y ambigüedades en la labor de la ACS. El AD ha demostrado ser una herramienta útil para el debate y la propiedad de la información de salud, debido al carácter relacional y no lineal de su contenido y su formato interactivo, no prescriptivo sobre dengue y

  2. Quantum Causal Graph Dynamics

    CERN Document Server

    Arrighi, Pablo

    2016-01-01

    Consider a graph having quantum systems lying at each node. Suppose that the whole thing evolves in discrete time steps, according to a global, unitary causal operator. By causal we mean that information can only propagate at a bounded speed, with respect to the distance given by the graph. Suppose, moreover, that the graph itself is subject to the evolution, and may be driven to be in a quantum superposition of graphs---in accordance to the superposition principle. We show that these unitary causal operators must decompose as a finite-depth circuit of local unitary gates. This unifies a result on Quantum Cellular Automata with another on Reversible Causal Graph Dynamics. Along the way we formalize a notion of causality which is valid in the context of quantum superpositions of time-varying graphs, and has a number of good properties. Keywords: Quantum Lattice Gas Automata, Block-representation, Curtis-Hedlund-Lyndon, No-signalling, Localizability, Quantum Gravity, Quantum Graphity, Causal Dynamical Triangula...

  3. Causal Inference and Causal Explanation with Background Knowledge

    OpenAIRE

    Meek, Christopher

    2013-01-01

    This paper presents correct algorithms for answering the following two questions; (i) Does there exist a causal explanation consistent with a set of background knowledge which explains all of the observed independence facts in a sample? (ii) Given that there is such a causal explanation what are the causal relationships common to every such causal explanation?

  4. As relações entre saúde e trabalho dos agentes de combate às endemias da Funasa: a perspectiva dos trabalhadores The relationship between health and work of FUNASA's endemic diseases combat agents

    OpenAIRE

    Hilka Flavia Saldanha Guida; Kátia Reis de Souza; Maria Blandina Marques dos Santos; Solange Maria Carvalho Lima da Silva; Valéria Pereira Silva

    2012-01-01

    O presente artigo analisa as relações entre saúde e trabalho dos agentes de combate às endemias (ACEs) da Fundação Nacional de Saúde (Funasa), lotados no município de Nova Iguaçu-RJ, que foram reintegrados ao quadro da administração pública após terem sido dispensados. Os objetivos principais deste estudo foram compreender a história da luta destes trabalhadores por reconhecimento social e justiça, cujo desfecho foi a readmissão ao trabalho, bem como conhecer os efeitos adversos na saúde em r...

  5. Determinación de Especies de Erwinia (grupo carotovora como Agentes Causales de “Pudrición Blanda” en Cala (Zantedeschia spp. Determination of Erwinia Species (carotovora group as Causal Agents of “Soft Rot” in Calla (Zantedeschia spp.

    Directory of Open Access Journals (Sweden)

    Juan Pablo Kunstmann

    2006-09-01

    Full Text Available Durante la temporada 2002 se realizó una investigación para establecer los agentes causantes de pudriciones húmedas en tallos y túberos de cala (Zantedeschia spp. provenientes de producciones bajo invernadero en el Sur de Chile. Para comparar con cepas locales se realizaron aislamientos a partir de tubérculos de papa (Solanum tuberosum L. obtenidas de una producción comercial cerca de la ciudad de Valdivia. Para analizar las diferencias en virulencia, las cepas de papa fueron inoculadas sobre cala y vice versa. De los aislamientos bacterianos obtenidos se determinaron 33 pertenecientes al género Erwinia (grupo carotovora(E.c. de acuerdo a las siguientes características: Gram (-, oxidasa (- y pudrición de rodajas de papa (+. Pruebas complementarias y más especificas incluyeron sensibilidad a la eritromicina, utilización de la palatinosa, sustancias reductoras a partir de sacarosa, producción de ácido a partir de a-metil glucósido y crecimiento a 37ºC. Finalmente, fue posible identificar dos cepas de E.c. subsp. atroseptica y 21 E.c. subsp. carotovora de túberos y plantas de cala. No hubo evidencia de la presencia de la especie fitopatógena E. chrysanthemi entre los aislamientos estudiados, una indicación que esta especie está ausente en Chile. Este es el primer informe sobre la presencia de aislamientos de la subespecie atroseptica afectando un nuevo cultivo como la cala en Chile. Las inoculaciones cruzadas demostraron que la virulencia es mayor con las cepas obtenidas de tejidos de cala. Las posibilidades que estas cepas sean foráneas son bastante altas, y pueden interferir con producciones de cultivos locales como la papa.

  6. A Universidade Federal da Fronteira Sul como agente promotor da agroecologia no território Cantuquiriguaçu-PR/ Brasil

    OpenAIRE

    Rauber, Ana Claudia; Leandrini, Josimeire A.; Franzener, Gilmar

    2015-01-01

    A Universidade Federal da Fronteira Sul (UFFS) com campi nos três estados da região Sul do Brasil foi uma conquista dos movimentos sociais. Um dos campus está localizado no Território da Cidadania Cantuquiriguaçu, município de Laranjeiras do Sul-PR. Esta experiência tem como objetivo demonstrar como a universidade contribuiu com a valorização do modo de ser camponês na região, e com a promoção e disseminação da Agroecologia no território, através do aumento da agrobiodiversidade e do resgate ...

  7. Ação de produtos químicos in vitro e in vivo sobre Clavibacter michiganensis subsp. michiganensis, agente causal do cancro bacteriano do tomateiro In vitro and in vivo action of chemicals on Clavibacter michiganensis subsp. michiganensis, causal agent of the bacterial canker of tomato

    Directory of Open Access Journals (Sweden)

    Gustavo de Faria Theodoro

    2000-09-01

    Full Text Available O presente trabalho teve como objetivo avaliar a sensibilidade in vitro e in vivo de um isolado de Clavibacter michiganensis subsp. michiganensis (Cmm aos produtos cloridrato de kasugamicina, fulusulfamide e oxitetraciclina. Para o teste in vitro, foram avaliados os halos de inibição formados ao redor de discos de papel de filtro umedecidos com os produtos, nas concentrações de 0, 1, 10, 100 e 1000 mig mL-1, 24 h após a instalação do ensaio. Quanto à avaliação dos produtos in vivo, dois ensaios foram instalados sob condições de casa-de-vegetação, com plantas de tomateiro cultivar Ângela Hiper, através da inoculação das plantas por dois métodos: pulverização foliar e ferimento no caule. Nos dois ensaios, as plantas foram pulverizadas com os produtos cloridrato de kasugamicina a 0,06 mL L-1, fulusulfamide a 0,025, 0,05 e 0,075 mL L-1 e oxitetraciclina a 0,40 g L-1, duas vezes antes e duas vezes após a inoculação, em intervalos médios de 5-7 dias. Foram avaliados a incidência de folíolos doentes (inoculação foliar e a severidade dos sintomas nas plantas inoculadas por ferimento no caule. Verificou-se que o isolado de Cmm foi sensível in vitro ao cloridrato de kasugamicina, ao fulusulfamide e à oxitetraciclina, respectivamente a partir das concentrações de 1000, 100 e 10 mig mL-1. Com relação aos ensaios in vivo, apenas oxitetraciclina propiciou menor incidência de folíolos doentes nas plantas inoculadas através de pulverização foliar; nenhum produto teve êxito em controlar a doença nas plantas inoculadas por ferimento no caule. O fulusulfamide, em todas as concentrações, foi fitotóxico aos folíolos das plantas de tomateiro.An experiment was carried out to evaluate the in vivo and in vitro sensibility of a Clavibacter michiganensis subsp. michiganensis isolate (Cmm to the products kasugamicyn cloridrate, fulusulfamide and oxytetracicline. In the in vitro tests, the inhibition formed around the discs of

  8. Causality and the Doppler Peaks

    OpenAIRE

    Turok, Neil

    1996-01-01

    Could cosmic structure have formed by the action of causal physics within the standard hot big bang, or was a prior period of inflation required? Recently there has been some discussion of whether causal sources could reproduce the pattern of Doppler peaks of the standard scale-invariant adiabatic theory. This paper gives a rigorous definition of causality, and a causal decomposition of a general source. I present an example of a simple causal source which mimics the standard adiabatic theory...

  9. Dynamics of Causal Sets

    CERN Document Server

    Rideout, D

    2002-01-01

    The Causal Set approach to quantum gravity asserts that spacetime, at its smallest length scale, has a discrete structure. This discrete structure takes the form of a locally finite order relation, where the order, corresponding with the macroscopic notion of spacetime causality, is taken to be a fundamental aspect of nature. After an introduction to the Causal Set approach, this thesis considers a simple toy dynamics for causal sets. Numerical simulations of the model provide evidence for the existence of a continuum limit. While studying this toy dynamics, a picture arises of how the dynamics can be generalized in such a way that the theory could hope to produce more physically realistic causal sets. By thinking in terms of a stochastic growth process, and positing some fundamental principles, we are led almost uniquely to a family of dynamical laws (stochastic processes) parameterized by a countable sequence of coupling constants. This result is quite promising in that we now know how to speak of dynamics ...

  10. Dynamics Of Causal Sets

    CERN Document Server

    Rideout, D P

    2001-01-01

    The Causal Set approach to quantum gravity asserts that spacetime, at its smallest length scale, has a discrete structure. This discrete structure takes the form of a locally finite order relation, where the order, corresponding with the macroscopic notion of spacetime causality, is taken to be a fundamental aspect of nature. After an introduction to the Causal Set approach, this thesis considers a simple toy dynamics for causal sets. Numerical simulations of the model provide evidence for the existence of a continuum limit. While studying this toy dynamics, a picture arises of how the dynamics can be generalized in such a way that the theory could hope to produce more physically realistic causal sets. By thinking in terms of a stochastic growth process, and positing some fundamental principles, we are led almost uniquely to a family of dynamical laws (stochastic processes) parameterized by a countable sequence of coupling constants. This result is quite promising in that we now know how to speak of dynamics ...

  11. Biased causal inseparable game

    CERN Document Server

    Bhattacharya, Some Sankar

    2015-01-01

    Here we study the \\emph{causal inseparable} game introduced in [\\href{http://www.nature.com/ncomms/journal/v3/n10/full/ncomms2076.html}{Nat. Commun. {\\bf3}, 1092 (2012)}], but it's biased version. Two separated parties, Alice and Bob, generate biased bits (say input bit) in their respective local laboratories. Bob generates another biased bit (say decision bit) which determines their goal: whether Alice has to guess Bob's bit or vice-verse. Under the assumption that events are ordered with respect to some global causal relation, we show that the success probability of this biased causal game is upper bounded, giving rise to \\emph{biased causal inequality} (BCI). In the \\emph{process matrix} formalism, which is locally in agreement with quantum physics but assume no global causal order, we show that there exist \\emph{inseparable} process matrices that violate the BCI for arbitrary bias in the decision bit. In such scenario we also derive the maximal violation of the BCI under local operations involving tracele...

  12. Blendas de poliamida 6/elastômero: propriedades e influência da adição de agente compatibilizante

    Directory of Open Access Journals (Sweden)

    Barra Guilherme M. O.

    2003-01-01

    Full Text Available Neste trabalho foram estudadas as propriedades micro e macroscópicas de misturas físicas binárias de poliamida 6 [PA6] com copolímero poli(etileno-co-propileno-co-dieno [EPDM] e em presença de pequenas quantidades de EPDM ou EPM enxertados com anidrido maleico, atuando como agentes compatibilizantes. Os componentes puros (poliamida 6 e EPDM e as blendas poliméricas em diferentes composições foram analisados por calorimetria diferencial de varredura (DSC e espectroscopia de infravermelho (FTIR. Os resultados indicaram a imiscibilidade dos componentes da mistura em toda a faixa de composição estudada. A utilização das técnicas de análise elementar, microscopia eletrônica de varredura e propriedades mecânicas permitiu avaliar a homogeneidade da mistura, a redução do tamanho dos domínios do elastômero e o aumento da força de impacto da matriz de PA6 com a adição do agente compatibilizante à mistura binária de PA6/EPDM.

  13. Strawberry sterility - What is the causal agent(s)?

    Czech Academy of Sciences Publication Activity Database

    Fránová, Jana; Petrzik, Karel

    Leueven 1 : ISHS Acta Horticulturea, 2008 - (Martin, R.), s. 27-34 ISBN 978-90-6605-038-9. ISSN 0567-7572. [International Symposium on Small Fruit Virus Diseases /11./. Antalya (TR), 22.05.2006-26.05.2006] R&D Projects: GA AV ČR(CZ) 1QS500510558 Institutional research plan: CEZ:AV0Z50510513 Keywords : strawberry sterility * biological experiments * viruses * PCR Subject RIV: EF - Botanics

  14. Daphne decline - what is the causal agent(s)?

    Czech Academy of Sciences Publication Activity Database

    Fránová, Jana; Lesemann, D.E.

    2007-01-01

    Roč. 51, č. 4 (2007), s. 275-281. ISSN 0001-723X R&D Projects: GA AV ČR(CZ) 1QS500510558 Institutional research plan: CEZ:AV0Z50510513 Keywords : plant pathology * Daphne Subject RIV: EE - Microbiology, Virology Impact factor: 0.560, year: 2007

  15. Strawberry sterility - what is the causal agent(s)?

    Czech Academy of Sciences Publication Activity Database

    Fránová, Jana; Petrzik, Karel

    2008-01-01

    Roč. 780, - (2008), s. 27-34. ISSN 0567-7572 R&D Projects: GA AV ČR(CZ) 1QS500510558 Institutional research plan: CEZ:AV0Z50510513 Keywords : plant pathology * strawberry sterility Subject RIV: EE - Microbiology, Virology

  16. Ensemble of Causal Trees

    International Nuclear Information System (INIS)

    We discuss the geometry of trees endowed with a causal structure using the conventional framework of equilibrium statistical mechanics. We show how this ensemble is related to popular growing network models. In particular we demonstrate that on a class of afine attachment kernels the two models are identical but they can differ substantially for other choice of weights. We show that causal trees exhibit condensation even for asymptotically linear kernels. We derive general formulae describing the degree distribution, the ancestor--descendant correlation and the probability that a randomly chosen node lives at a given geodesic distance from the root. It is shown that the Hausdorff dimension dH of the causal networks is generically infinite. (author)

  17. Ensemble of Causal Trees

    Science.gov (United States)

    Bialas, Piotr

    2003-10-01

    We discuss the geometry of trees endowed with a causal structure using the conventional framework of equilibrium statistical mechanics. We show how this ensemble is related to popular growing network models. In particular we demonstrate that on a class of afine attachment kernels the two models are identical but they can differ substantially for other choice of weights. We show that causal trees exhibit condensation even for asymptotically linear kernels. We derive general formulae describing the degree distribution, the ancestor--descendant correlation and the probability that a randomly chosen node lives at a given geodesic distance from the root. It is shown that the Hausdorff dimension dH of the causal networks is generically infinite.

  18. Causal graph dynamics

    CERN Document Server

    Arrighi, Pablo

    2012-01-01

    We generalize the theory of Cellular Automata to arbitrary, time-varying graphs. In other words we formalize, and prove theorems about, the intuitive idea of a labelled graph which evolves in time - but under the natural constraint that information can only ever be transmitted at a bounded speed, with respect to the distance given by the graph. The notion of translation-invariance is also generalized. The definition we provide for these `causal graph dynamics' is simple and axiomatic. The theorems we provide also show that it is robust. For instance, causal graph dynamics are stable under composition and under restriction to radius one. In the finite case some fundamental facts of Cellular Automata theory carry through: causal graph dynamics admit a characterization as continuous functions and they are stable under inversion. The provided examples suggest a wide range of applications of this mathematical object, from complex systems science to theoretical physics. Keywords: Dynamical networks, Boolean network...

  19. Causal inference in econometrics

    CERN Document Server

    Kreinovich, Vladik; Sriboonchitta, Songsak

    2016-01-01

    This book is devoted to the analysis of causal inference which is one of the most difficult tasks in data analysis: when two phenomena are observed to be related, it is often difficult to decide whether one of them causally influences the other one, or whether these two phenomena have a common cause. This analysis is the main focus of this volume. To get a good understanding of the causal inference, it is important to have models of economic phenomena which are as accurate as possible. Because of this need, this volume also contains papers that use non-traditional economic models, such as fuzzy models and models obtained by using neural networks and data mining techniques. It also contains papers that apply different econometric models to analyze real-life economic dependencies.

  20. A Causal Entropy Bound

    CERN Document Server

    Brustein, Ram

    2000-01-01

    The identification of a causal-connection scale motivates us to propose a new covariant bound on entropy within a generic space-like region. This "causal entropy bound", scaling as the square root of EV, and thus lying around the geometric mean of Bekenstein's S/ER and holographic S/A bounds, is checked in various "critical" situations. In the case of limited gravity, Bekenstein's bound is the strongest while naive holography is the weakest. In the case of strong gravity, our bound and Bousso's holographic bound are stronger than Bekenstein's, while naive holography is too tight, and hence typically wrong.

  1. A Causal Entropy Bound

    OpenAIRE

    Brustein, R; Veneziano, G

    1999-01-01

    The identification of a causal-connection scale motivates us to propose a new covariant bound on entropy within a generic space-like region. This "causal entropy bound", scaling as the square root of EV, and thus lying around the geometric mean of Bekenstein's S/ER and holographic S/A bounds, is checked in various "critical" situations. In the case of limited gravity, Bekenstein's bound is the strongest while naive holography is the weakest. In the case of strong gravity, our bound and Bousso...

  2. Causality and Free Will

    Czech Academy of Sciences Publication Activity Database

    Hvorecký, Juraj

    2012-01-01

    Roč. 19, Supp.2 (2012), s. 64-69. ISSN 1335-0668 R&D Projects: GA ČR(CZ) GAP401/12/0833 Institutional support: RVO:67985955 Keywords : conciousness * free will * determinism * causality Subject RIV: AA - Philosophy ; Religion

  3. Libertad de la voluntad y poderes causales Freedom of the will and causal powers

    Directory of Open Access Journals (Sweden)

    JOSÉ TOMÁS ALVARADO MARAMBIO

    2012-03-01

    Full Text Available Este trabajo discute una objeción bien conocida a la libertad de la voluntad libertaria en un mundo no determinista. En un mundo no determinista el estado de cosas total del mundo en un instante de tiempo t es compatible con diferentes estados de cosas totales alternativos en el futuro de t. Se ha argumentado que, en cuanto son posibles diferentes alternativas a una decisión libre, es una cuestión de azar y suerte que tal decisión se ha tomado. Si una decisión libre es una cuestión de suerte, entonces el agente no puede ser considerado responsable por ella. Se argumenta que la dificultad aparece en una concepción anti-realista de la causalidad, donde los hechos causales son supervenientes a regularidades o dependencias contrafácticas. Una concepción realista de la causalidad puede, por ello, explicar cómo el agente está en control causal de la decisión libre tomada, cuando la decisión no cae bajo una regularidad o una dependencia contrafáctica. Una vez considerado cómo es que el agente está en control de la decisión, se argumenta que no se puede decir que la decisión libre es una cuestión de suerte para el agente.This paper discusses a well-known objection to libertarian free will in a non-deterministic world. In a non-deterministic world the complete state of affairs of the world in an instant of time t is compatible with different alternative complete states of affairs in the future of t. It has been argued that, in so far as different alternatives are possible to a free decision, it is a matter of chance and luck that that decision is taken. If a free decision is a matter of luck, then the agent cannot be considered responsible for it. It is argued that the difficulty appears from an anti-realist conception of causality, where causal facts are supervenient on regularities or counterfactual dependences. A realist conception of causality can, then, explain how the agent is causally in control of the free decision taken when

  4. Respuesta al glifosato de un aislamiento de Rhizoctonia solani agente causal del anublo de la vaina del arroz, y de cuatro aislamientos de Trichoderma, bajo condiciones in vitro In vitro response of one isolate of Rhizoctonia solani, the pathogen of the rice sheath blight and four isolates of Trichoderma to glyphosate

    OpenAIRE

    Vargas de Álvarez Amparo; Fuentes Cilia L.; Torres Torres Enrique

    2002-01-01

    El añublo de la vaina del arroz (Orysa saliva L.), cuyo agente causal es Rhizoctonia solani Kuhn, es una de las enfermedades más importantes en el cultivo del arroz en Colombia. En los cultivos de arroz con frecuencia se aplica glifosato ((ácido N-(fosfonometil) glicina) para controlar las malezas, particularmente el arroz rojo (O. saliva), antes de la siembra del arroz. Observaciones de campo anteriores parecían indicar relación entre el uso intensivo del glifosato y el incremento en la inci...

  5. Primeiro relato da podridão da estipe da pupunheira, causada por Phytophthora palmivora, no estado do Paraná First report of stem rot on peach palm caused by Phytophthora palmivora ain the State of Paraná

    Directory of Open Access Journals (Sweden)

    Álvaro F. dos Santos

    2004-12-01

    Full Text Available Phytophthora palmivora foi isolado de plantas de pupunheira (Bactris gasipaes com sintomas de podridão da estipe, no Paraná, em 2002. Testes de patogenicidade e o subseqüente reisolamento do fungo confirmaram a hipótese de que P. palmivora é o agente causal da podridão do estipe. Este é o primeiro relato de P. palmivora causando podridão do estipe na pupunheira no estado do Paraná.Phytophthora palmivora was isolated from infected peach palm (Bactris gasipaes plants with stem rot symptoms in Paraná State, in 2002. Pathogenicity tests and subsequent reisolations of P. palmivora confirmed the hypothesis that this fungus was the causal agent of the disease. This is the first report of P. palmivora causing stem rot on peach palm (Bactris gasipaes in the southern State of Paraná.

  6. Análise da rugosidade superficial de materiais restauradores estéticos: efeito de agentes clareadores e tempo = Analysis of roughness surface of aesthetic restoring materials: effect of bleaching agentes and time

    Directory of Open Access Journals (Sweden)

    Pozzobon, Roselaine Terezinha

    2005-01-01

    Full Text Available Este estudo in vitro avaliou o efeito de agentes clareadores na rugosidade superficial (Ra de materiais restauradores estéticos, com o passar do tempo. Foram utilizadas duas resinas compostas, Z100 (M1 e Silux-Plus (M2, um compômero, Dyract (M3 e um ionômero de vidro modificado por resina, Vitremer (M4, que foram expostos a dois agentes clareadores: Opalescence (C1, peróxido de carbamida 10%, e Hi-Lite (C2, peróxido de hidrogênio 35% e como meio de imersão foi utilizada saliva artificial (Co. Foram confeccionados 120 corpos de prova, sendo a Ra avaliada após 1 hora de confecção; e antes da imersão em saliva artificial (T0, após 1dia (T1, 7 (T2, 15 (T3 e 30 (T4 dias de exposição aos agentes clareadores. No grupo controle, os corpos-de-prova ficaram somente imersos em saliva artificial. Após análise estatística de variância ANOVA (a = 5%, teste de Tukey, e método da decomposição da soma de quadrados, foi possível concluir que: 1 – a Ra dos materiais restauradores estéticos, de forma geral, alterou-se após exposição aos diferentes agentes clareadores e ao longo do tempo; 2 – em função do material restaurador, M2 apresentou a maior média de Ra, seguido em ordem decrescente por M4, M3 e M1; 3 – C1 e C2 exerceram ação sobre a superfície dos materiais restauradores aumentando a Ra para todos os materiais avaliados, principalmente em M2 e M4; 4 – em função do fator tempo, observou-se influência estatisticamente significativa sobre a Ra, pois quanto maior o tempo de exposição ao agente clareador, maiores os valores médios de Ra.

  7. O projeto cultural de PLE como agente da interculturalidade num contexto de não-­imersão

    Directory of Open Access Journals (Sweden)

    Eliete Farneda Sampaio

    2015-12-01

    Full Text Available O objetivo desta pesquisa foi investigar os aspectos interculturais no processo de ensino/ aprendizagem de Português Língua Estrangeira, no contexto de não-imersão. Através da introdução de tarefas comunicativas e da abordagem comunicativa procurou-­se determinar o que é cultura (Mendes, 2010 e qual cultura deve ser ensinada durante o processo de ensino/ aprendizagem de uma língua estrangeira (Khramsch, 2013, entre outros. Os resultados nos mostraram, a percepção da interculturalidade tida pelo aprendente durante a realização do projeto cultural, relacionando a sua cultura com a cultura do outro e minimizando as ideias esteriotipadas anteriormente tidas sobre a cultura da língua-­alvo.

  8. Caracterização morfofisiológica e identificação molecular de isolados de Guignardia citricarpa, agente patogênico da mancha preta dos citros = Morphophysiological characterization and molecular identification of isolates of Guignardia citricarpa, a pathogenic agent of the citrus black spot

    Directory of Open Access Journals (Sweden)

    Marilda Pereira Caixeta

    2008-12-01

    Full Text Available O presente trabalho teve como objetivo identificar 11 isolados de Guignardia citricarpa, agente causal da mancha preta dos citros (MPC, obtidos de frutas cítricas sintomáticas de diferentes regiões geográficas, por meio da PCR e caracterização morfofisiológica das estruturas propagativas, esporulação e crescimento micelial emdiferentes meios de cultura, temperaturas e regimes de luz, nas condições de laboratório. Pelo teste de PCR, todos os isolados foram identificados como o patógeno G. citricarpa. Os isolados caracterizados foram submetidos às temperaturas de 20, 25 e 30ºC, em regime de luz contínua, escuro contínuo e fotoperíodos de 12 horas, durante 24 dias. Utilizaram-se os meios de cultura aveia-ágar (AA, batata-dextrose-ágar (BDA e cenoura-dextrose-ágar (CDA. Os resultados mostraram que ocorreu interação entre os diferentes meios de cultura, temperaturas e fotoperíodos. O meio de cultura que melhor estimulou o crescimento micelial foi o CDA a 25ºC sob o fotoperíodo de 12h. A maior produção de esporos (conídios foi verificada no meio BDA a 20ºC, no fotoperíodo de 12 horas. No meio CDA, não ocorreu esporulação de nenhum isolado. Sob a temperatura de 30ºC, foiverificada apenas a produção de hifas e picnídios para a maioria dos isolados, em todos os meios de cultura e fotoperíodo testados.Thepresent work aims to identify 11 isolates of Guignardia citricarpa, the causal agent of the citrus black spot (CBS, obtained from affected fruit in different geographical regions, through PCR and morphophysiological characterization of propagative structures, sporing and mycelial growth in different means of culture, temperatures and photoperiods, under laboratory conditions. Through the PCR test, all isolates were identified as being the G.citricarpa pathogen. The characterized isolates were subjected to evaluations at temperatures of 20, 25 and 30ºC, in continuous light, continuous darkness, and alternating 12

  9. Tachyon Kinematics and causality

    International Nuclear Information System (INIS)

    The chronological order of the events along a space-like path is not invariant under Lorentz transformations, as wellknown. This led to an early conviction that tachyons would give rise to causal anomalies. A relativistic version of the Stuckelberg-Feynman switching procedure (SWP) has been invoked as the suitable tool to eliminate those anomalies. The application of the SWP does eliminate the motions backwards in time, but interchanges the roles of source and dector. This fact triggered the proposal of a host of causal paradoxes. Till now, however, it has not been recognized that such paradoxes can be sensibly discussed (and completely solved, at least in microphysics) only after having properly developed the tachyon relativistic mechanics. We start by showing how to apply the SWP, both in the case of ordiry Special Relativity, and in the case with tachyons. Then, we carefully exploit the kinematics of the tachyon-exchange between to (ordinary) bodies. Being finally able to tackle the tachyon-causality problem, we successively solve the paradoxes: (i) by Tolman-Regge; (ii) by Pirani; (iii) by Edmonds; (iv) by Bell. At last, we discuss a further, new paradox associated with the transmission of signals by modulated tachyon beams

  10. Causality between time series

    CERN Document Server

    Liang, X San

    2014-01-01

    Given two time series, can one tell, in a rigorous and quantitative way, the cause and effect between them? Based on a recently rigorized physical notion namely information flow, we arrive at a concise formula and give this challenging question, which is of wide concern in different disciplines, a positive answer. Here causality is measured by the time rate of change of information flowing from one series, say, X2, to another, X1. The measure is asymmetric between the two parties and, particularly, if the process underlying X1 does not depend on X2, then the resulting causality from X2 to X1 vanishes. The formula is tight in form, involving only the commonly used statistics, sample covariances. It has been validated with touchstone series purportedly generated with one-way causality. It has also been applied to the investigation of real world problems; an example presented here is the cause-effect relation between two climate modes, El Ni\\~no and Indian Ocean Dipole, which have been linked to the hazards in f...

  11. COM QUE ROUPA EU VOU? O JORNALISTA ESPECIALIZADO COMO FORMADOR DE OPINIÃO E AGENTE DE CONSAGRAÇÃO NO CAMPO DA MODA

    OpenAIRE

    Virgínia Todeschini Borges

    2014-01-01

    Este artigo examina o papel do jornalista moda como formador de opinião e como um dos agentes de consagração no campo da moda. Tendo como base pesquisa bibliográfica e realização de entrevistas qualitativas como metodologia de coleta de dados, procuramos responder as seguintes perguntas: Quem dita a moda na atualidade? Como é o trabalho de um jornalista de moda? Qual a importância destes formadores de opinião no lançamento de tendências de moda?

  12. Restauración en el Inmunoblotting de proteínas de Neisseria meningitidis dañadas por calor y agentes reductores

    OpenAIRE

    Rolando Ochoa; Xenia Ferriol; Ana García; Juan Carlos Martínez; Franklin Sotolongo

    2015-01-01

    En este trabajo se utilizaron cinco detergentes para restaurar las proteínas de membrana externas (PME) del meningococo dañadas por el efecto del calor y de agentes reductores utilizados en el Inmunoblotting. La acción de los detergentes fue evaluada en la solución de lavado, en el diluente de la muestra y del conjugado. Las bandas de proteínas, reconocidas por la IgG del suero, fueron identificadas usando un conjugado anti IgG humana peroxidasa. Los antígenos reconocidos por el control posit...

  13. Revisiting Causality in Markov Chains

    CERN Document Server

    Shojaee, Abbas

    2016-01-01

    Identifying causal relationships is a key premise of scientific research. The growth of observational data in different disciplines along with the availability of machine learning methods offers the possibility of using an empirical approach to identifying potential causal relationships, to deepen our understandings of causal behavior and to build theories accordingly. Conventional methods of causality inference from observational data require a considerable length of time series data to capture cause-effect relationship. We find that potential causal relationships can be inferred from the composition of one step transition rates to and from an event. Also known as Markov chain, one step transition rates are a commonly available resource in different scientific disciplines. Here we introduce a simple, effective and computationally efficient method that we termed 'Causality Inference using Composition of Transitions CICT' to reveal causal structure with high accuracy. We characterize the differences in causes,...

  14. Effects of Jinggangmycin on the growth and development of Rhizoctonia solani Kühn causal agent of rice sheath blight%井冈霉素对水稻纹枯病菌生长发育的影响

    Institute of Scientific and Technical Information of China (English)

    杨媚; 杨迎青; 李明海; 舒灿伟; 周而勋

    2012-01-01

    以水稻纹枯病菌(Rhizoctonia solani Kühn)强致病菌株GD-118为供试菌株,在室内观察了井冈霉素(Jinggangmycin)对其生长发育的影响.结果表明:井冈霉素对水稻纹枯病菌的毒力回归方程为y=3.3603+1.3204x,相关系数r=0.9626,理论抑制菌丝生长的EC5o为70.2μg/mL,EC95为6341.5μg/mL.与不加井冈霉素的空白对照相比,用井冈霉素处理后水稻纹枯病菌的菌落边缘明显凹凸不平,边缘菌丝更密集、颜色加深,并且随着井冈霉素处理浓度的增加,菌丝的干质量逐渐降低,但菌落表面菌丝的密集程度有所增加、颜色更深;空白对照的菌核呈颗粒状、褐色,散生于菌落表面,边缘较多而中间较少;用井冈霉素处理后的菌核多数为粉状、浅褐色,部分菌核会连在一起呈块状,分布在菌落外围呈明显的双环形,具不规则的凹凸型菌落边缘,并且随着井冈霉素处理浓度的增加,菌核的干质量有所增加,菌核出现时间比空白对照提前约24 h.另外,随着井冈霉素处理浓度的增加,水稻纹枯病菌的菌丝细胞核平均数目和分布范围均有不正常增多的趋势.%The effects of Jinggangmycin on the growth and development of Rhizoctonia solani K(u)hn causal agent of rice sheath blight, were investigated by using a virulent isolate GD-118 of R. Solani as the test isolate. The results showed that the regression equation for Jinggangmycin toxicity to R. Solani was: y=3. 360 3+1. 320 4χ, correlation coefficient r=0. 962 6,the EC50 for theoretical inhibition of my-celial growth was 70. 2 μg/mL, and the EC95 was 6 341. 5 μg/mL. In regarding to cultural characteristics and mycelial growth,compared with blank control (without Jinggangmycin), the colonies of Jinggangmycin treatments had relatively obvious characteristics of uneven edges with more dense mycelia and darkened colour in the plate; with the increase of Jinggangmycin concentrations, the dry weight of mycelia decreased, but

  15. Addition of a hypoxic cell selective cytotoxic agent (mitomycin C or porfiromycin) to Fluosol-DA/carbogen/radiation

    Energy Technology Data Exchange (ETDEWEB)

    Holden, S.A.; Teicher, B.A. (Dana-Farber Cancer Institute, Boston (USA)); Herman, T.S. (Dana-Farber Cancer Institute, Boston (USA) Joint Center for Radiation Therapy, Boston (USA))

    1990-05-01

    In an effort to develop effictive combination treatments for use with radiation against solid tumors, the cytotoxic effects of the addition of mitomycin C or porfiromycin on treatment with Fluosol-DA/carbogen breathing and radiation in the FSaIIC tumor system were studied. In vitro mitomycin C and porfiromycin were both preferentially cytotoxic toward hypoxic FSaIIC cells. After in vivo exposure, however, the cytotoxicity of mitomycin C toward single cell tumor suspensions obtained from whole tumors was exponential over the dose range studied, but for porfiromycin a plateau in cell killing was observed. With Fluosol-DA/carbogen breathing and single dose radiaiton, addition of either mitomycin C or porfiromycin increased the tumor cell kill achieved at 5 Gy by approximately 1.2 and 1.0 logs, respectively. Less effect was seen with addition of the drugs at the 10 and 15 Gy radiation doses. In tumor growth delay experiments, the addition of either mitomycin C or porfiromycin to Fluosol-DA/carbogen breathing and radiation resulted in primarily an additive increase in tumor growth delay. The survival of Hoechst 33342 dye-selected tumor cell subpopulations indicated that Fluosol-DA/carbogen breathing increased the cytotoxicity of radiation (10 Gy) more in the bright cell subpopulation (4-fold) than in the dim cell subpopulation (2-fold) resulting in an overall 4-fold sparing of the dim subpopulation. Mitomycin C and porfiromycin were both more toxic toward the dim cell subpopulations. Addition of mitomycin C or porfiromycin to Fluosol-DA/carbogen breathing and radiation (10 Gy) resulted in a primarily additive effect of the drugs and radiation killing in both tumor cell subpopulations. Thus, with mitomycin C/Fluosol-DA/carbogen and radiation there was a 2-fold sparing of dim cells and with profiromycin in the combined treatment a 1.6-fold sparing of the dim cell population. (Abstract Truncated)

  16. Quantum information causality.

    Science.gov (United States)

    Pitalúa-García, Damián

    2013-05-24

    How much information can a transmitted physical system fundamentally communicate? We introduce the principle of quantum information causality, which states the maximum amount of quantum information that a quantum system can communicate as a function of its dimension, independently of any previously shared quantum physical resources. We present a new quantum information task, whose success probability is upper bounded by the new principle, and show that an optimal strategy to perform it combines the quantum teleportation and superdense coding protocols with a task that has classical inputs. PMID:23745844

  17. Inferring deterministic causal relations

    OpenAIRE

    Daniusis, Povilas; Janzing, Dominik; Mooij, Joris; Zscheischler, Jakob; Steudel, Bastian; Zhang, Kun; Schoelkopf, Bernhard

    2012-01-01

    We consider two variables that are related to each other by an invertible function. While it has previously been shown that the dependence structure of the noise can provide hints to determine which of the two variables is the cause, we presently show that even in the deterministic (noise-free) case, there are asymmetries that can be exploited for causal inference. Our method is based on the idea that if the function and the probability density of the cause are chosen independently, then the ...

  18. Electrochemical and calorimetric investigation of interaction of novel biscationic anticancer agents with DNA; Investigacao eletroquimica e calorimetrica da interacao de novos agentes antitumorais biscationicos com DNA

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Lauris Lucia da; Donnici, Claudio Luis; Lopes, Julio Cesar Dias, E-mail: cdonnici@terra.com.br [Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil). Inst. de Ciencias Exatas. Dept. de Quimica; Goulart, Marilia Oliveira Fonseca; Abreu, Fabiane Caxico de; Paula, Francine Santos de [Universidade Federal de Alagoas (UFAL), Maceio, AL (Brazil). Campus A.C. Simoes. Inst. de Quimica e Biotecnologia; Bravo, Carlos E. Salas; Santoro, Marcelo Matos [Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil). Dept. de Bioquimica e Imunologia; Denadai, Angelo Marcio Leite [Centro Federal de Educacao Tecnologica, Timoteo, MG (Brazil). Campus VII; Santos, Alexandre Martins Costa [Universidade Federal do Espirito Santo, Vitoria, ES (Brazil). Dept. de Ciencias Fisiologicas; Montanari, Carlos Alberto [Universidade de Sao Paulo, Sao Carlos, SP (Brazil). Inst. de Quimica

    2012-07-01

    Biscationic amidines bind in the DNA minor groove and present biological activity against a range of infectious diseases. Two new biscationic compounds (bis-{alpha}-{omega}-S-thioureido, amino and sulfide analogues) were synthesized in good yields and fully characterized, and their interaction with DNA was also investigated. Isothermal titration calorimetry (ITC) was used to measure the thermodynamic properties of binding interactions between DNA and these ligands. A double stranded calf thymus DNA immobilized on an electrode surface was used to study the possible DNA-interacting abilities of these compounds towards dsDNA in situ. A remarkable interaction of these compounds with DNA was demonstrated and their potential application as anticancer agents was furthered. (author)

  19. As relações entre saúde e trabalho dos agentes de combate às endemias da Funasa: a perspectiva dos trabalhadores The relationship between health and work of FUNASA's endemic diseases combat agents

    Directory of Open Access Journals (Sweden)

    Hilka Flavia Saldanha Guida

    2012-12-01

    Full Text Available O presente artigo analisa as relações entre saúde e trabalho dos agentes de combate às endemias (ACEs da Fundação Nacional de Saúde (Funasa, lotados no município de Nova Iguaçu-RJ, que foram reintegrados ao quadro da administração pública após terem sido dispensados. Os objetivos principais deste estudo foram compreender a história da luta destes trabalhadores por reconhecimento social e justiça, cujo desfecho foi a readmissão ao trabalho, bem como conhecer os efeitos adversos na saúde em razão das condições da atividade de combate a endemias. Adotou-se como base metodológica os estudos participativos e, complementarmente, o enfoque da educação popular, realizando grupos de discussão com os trabalhadores. Trata-se, por conseguinte, de uma pesquisa de cunho pedagógico, na qual o diálogo é a relação fundamental. Dos temas identificados nos grupos de discussão obteve-se um repertório de problemas e questões que evidenciaram as más condições de trabalho e a desregulamentação de políticas de saúde voltada para os trabalhadores. Os próprios trabalhadores reconhecem a precarização de seu trabalho, conferindo grande responsabilidade à interferência da política. Referiram-se ainda a um período de incertezas, sofrido pela indefinição de responsabilidades entre os níveis de governo, durante o período de descentralização político-administrativa, e seus efeitos negativos na saúde. Mencionaram o possível aspecto de toxicidade dos inseticidas e os seus riscos de contaminação. Foram sinalizadas sugestões que podem ser adotadas, de modo a propiciar melhores condições de trabalho e de saúde.This article analyses the relationship between health and work of the Agentes de Combate às Endemias (ACE - endemic diseases combat agents of Fundação Nacional de Saúde (FUNASA who work in the city of Nova Iguaçu (Southeastern Brazil and who were readmitted after being dismissed. It aims to give visibility to

  20. The PLS agent : agent behavior validation by partial least squares

    OpenAIRE

    Lorscheid, Iris; Meyer, Matthias; Pakur, Sandra; Ringle, Christian

    2014-01-01

    Agent-based modeling is widely applied in the social sciences. However, the validation of agent behavior is challenging and identified as one of the shortcomings in the field. Methods are required to establish empirical links and support the implementation of valid agent models. This paper contributes to this, by introducing the PLS agent concept. This approach shows a way to transfer results about causalities and decision criteria from empirical surveys into an agent-based decision model, th...

  1. Fusarium oxysporum strains as biocontrol agents against Fusarium wilt: effects on soil microbial biomass and activity Linhagens de Fusarium oxysporum como agentes de biocontrole da murcha-de-Fusarium: efeitos na biomassa e atividade microbiana do solo

    Directory of Open Access Journals (Sweden)

    Raquel Ghini

    2000-01-01

    Full Text Available Before planning the large-scale use of nonpathogenic strains of Fusarium oxysporum as biocontrol agents of Fusarium wilt, their behaviour and potential impact on soil ecosystems should be carefully studied as part of risk assessment. The aim of this work was to evaluate the effects of antagonistic F. oxysporum strains, genetically manipulated (T26/6 or not (233/1, on soil microbial biomass and activity. The effects were evaluated, in North-western Italy, in two soils from different sites at Albenga, one natural and the other previously solarized, and in a third soil obtained from a 10-year-old poplar stand (Popolus sp., near Carignano. There were no detectable effects on ATP, fluorescein diacetate hydrolysis, and biomass P that could be attributed to the introduction of the antagonists. A transient increase of carbon dioxide evolution and biomass C was observed in response to the added inoculum. Although the results showed only some transient alterations, further studies are required to evaluate effects on specific microorganism populations.Antes do uso em larga escala de linhagens não-patogênicas de Fusarium oxysporum como agentes de biocontrole da murcha-de-Fusarium, o seu comportamento e seus impactos potenciais no solo devem ser estudados como parte da avaliação de riscos. O objetivo do presente trabalho foi avaliar os efeitos de linhagens antagonistas de F. oxysporum, geneticamente manipuladas (T26/6 ou não (233/1, na biomassa e atividade microbiana do solo. Os efeitos foram avaliados no noroeste da Itália em dois solos de Albenga, sendo um natural e outro previamente solarizado, e em um terceiro solo obtido numa plantação de 10 anos de Popolus sp., em Carignano. Não foram observados efeitos significativos na quantidade de ATP, hidrólise de diacetato de fluoresceina e biomassa P, após a introdução dos antagonistas. Um aumento transitório foi observado na evolução de dióxido de carbono e no carbono da biomassa em resposta

  2. Causal inference based on counterfactuals

    Directory of Open Access Journals (Sweden)

    Höfler M

    2005-09-01

    Full Text Available Abstract Background The counterfactual or potential outcome model has become increasingly standard for causal inference in epidemiological and medical studies. Discussion This paper provides an overview on the counterfactual and related approaches. A variety of conceptual as well as practical issues when estimating causal effects are reviewed. These include causal interactions, imperfect experiments, adjustment for confounding, time-varying exposures, competing risks and the probability of causation. It is argued that the counterfactual model of causal effects captures the main aspects of causality in health sciences and relates to many statistical procedures. Summary Counterfactuals are the basis of causal inference in medicine and epidemiology. Nevertheless, the estimation of counterfactual differences pose several difficulties, primarily in observational studies. These problems, however, reflect fundamental barriers only when learning from observations, and this does not invalidate the counterfactual concept.

  3. Experimental test of nonlocal causality.

    Science.gov (United States)

    Ringbauer, Martin; Giarmatzi, Christina; Chaves, Rafael; Costa, Fabio; White, Andrew G; Fedrizzi, Alessandro

    2016-08-01

    Explaining observations in terms of causes and effects is central to empirical science. However, correlations between entangled quantum particles seem to defy such an explanation. This implies that some of the fundamental assumptions of causal explanations have to give way. We consider a relaxation of one of these assumptions, Bell's local causality, by allowing outcome dependence: a direct causal influence between the outcomes of measurements of remote parties. We use interventional data from a photonic experiment to bound the strength of this causal influence in a two-party Bell scenario, and observational data from a Bell-type inequality test for the considered models. Our results demonstrate the incompatibility of quantum mechanics with a broad class of nonlocal causal models, which includes Bell-local models as a special case. Recovering a classical causal picture of quantum correlations thus requires an even more radical modification of our classical notion of cause and effect. PMID:27532045

  4. Relationship of causal effects in a causal chain and related inference

    Institute of Scientific and Technical Information of China (English)

    GENG; Zhi; HE; Yangbo; WANG; Xueli

    2004-01-01

    This paper discusses the relationship among the total causal effect and local causal effects in a causal chain and identifiability of causal effects. We show a transmission relationship of causal effects in a causal chain. According to the relationship, we give an approach to eliminating confounding bias through controlling for intermediate variables in a causal chain.

  5. Relativistic hydrodynamics - causality and stability

    OpenAIRE

    Ván, P.; Biró, T. S.

    2007-01-01

    Causality and stability in relativistic dissipative hydrodynamics are important conceptual issues. We argue that causality is not restricted to hyperbolic set of differential equations. E.g. heat conduction equation can be causal considering the physical validity of the theory. Furthermore we propose a new concept of relativistic internal energy that clearly separates the dissipative and non-dissipative effects. We prove that with this choice we remove all known instabilities of the linear re...

  6. Addition of a hypoxic cell selective cytotoxic agent (mitomycin C or porfiromycin) to Fluosol-DA/carbogen/radiation.

    Science.gov (United States)

    Holden, S A; Herman, T S; Teicher, B A

    1990-05-01

    In an effort to develop effective combination treatments for use with radiation against solid tumors, the cytotoxic effects of the addition of mitomycin C or porfiromycin on treatment with Fluosol-DA/carbogen (95% O2/5% CO2) breathing and radiation in the FSaIIC tumor system were studied. In vitro mitomycin C and porfiromycin were both preferentially cytotoxic toward hypoxic FSaIIC cells. After in vivo exposure, however, the cytotoxicity of mitomycin C toward single cell tumor suspensions obtained from whole tumors was exponential over the dose range studied, but for porfiromycin a plateau in cell killing was observed. With Fluosol-DA/carbogen breathing and single dose radiation, addition of either mitomycin C or porfiromycin increased the tumor cell kill achieved at 5 Gy by approximately 1.2 and 1.0 logs, respectively. Less effect was seen with addition of the drugs at the 10 and 15 Gy radiation doses. In tumor growth delay experiments, the addition of either mitomycin C or porfiromycin to Fluosol-DA/carbogen breathing and radiation resulted in primarily an additive increase in tumor growth delay. The survival of Hoechst 33342 dye-selected tumor cell subpopulations indicated that Fluosol-DA/carbogen breathing increased the cytotoxicity of radiation (10 Gy) more in the bright cell subpopulation (4-fold) than in the dim cell subpopulation (2-fold) resulting in an overall 4-fold sparing of the dim subpopulation. Mitomycin C and porfiromycin were both more toxic toward the dim cell subpopulations. Addition of mitomycin C or porfiromycin to Fluosol-DA/carbogen breathing and radiation (10 Gy) resulted in a primarily additive effect of the drugs and radiation killing in both tumor cell subpopulations. Thus, with mitomycin C/Fluosol-DA/carbogen and radiation there was a 2-fold sparing of dim cells and with porfiromycin in the combined treatment a 1.6-fold sparing of the dim cell population. Our results indicate that treatment strategies directed against both oxic and

  7. Agente Comunitário de Saúde no controle da tuberculose na Atenção Primária à Saúde Agente Comunitario de Salud en el control de la tuberculosis en la Atención Primaria a la Salud The Community Health Agent in the control of tuberculosis in Primary Health Care

    OpenAIRE

    Juliane de Almeida Crispim; Beatriz Estuque Scatolin; Laís Mara Caetano da Silva; Ione Carvalho Pinto; Pedro Fredemir Palha; Ricardo Alexandre Arcêncio

    2012-01-01

    OBJETIVO: Avaliar o desempenho do Agente Comunitário de Saúde (ACS) no controle da tuberculose (TB) em áreas assistidas pela Estratégia Saúde da Família (ESF), sendo estabelecida uma análise comparativa com os ACSs inscritos nas Unidades Básicas de Saúde (UBS) tradicionais. MÉTODOS: Estudo transversal, realizado em um município prioritário para o controle da TB no Estado de São Paulo, com uma amostra mínima de 108 ACSs das ESFs e das UBSs. Para a coleta de dados, utilizou-se um instrumento el...

  8. Restauración en el Inmunoblotting de proteínas de Neisseria meningitidis dañadas por calor y agentes reductores

    Directory of Open Access Journals (Sweden)

    Rolando Ochoa

    2015-12-01

    Full Text Available En este trabajo se utilizaron cinco detergentes para restaurar las proteínas de membrana externas (PME del meningococo dañadas por el efecto del calor y de agentes reductores utilizados en el Inmunoblotting. La acción de los detergentes fue evaluada en la solución de lavado, en el diluente de la muestra y del conjugado. Las bandas de proteínas, reconocidas por la IgG del suero, fueron identificadas usando un conjugado anti IgG humana peroxidasa. Los antígenos reconocidos por el control positivo se corresponden con las proteínas P1, P3, P4 y P5 atendiendo a su peso molecular. Además, fueron reconocidas bandas de 80, 70, 24 kDa y otra con peso mayor a 150 kDa. En general el reconocimiento de todas las PME, excepto esta última de alto peso molecular (APM, se vieron favorecidas con la utilización del Tween 20, con el que se logró un incremento del número y la intensidad de las bandas así como la disminución de los fondos con respecto al resto de detergentes evaluados (Empigen BB, Triton X-100, Nonidet NP-40 y CHAPS. El reconocimiento de la proteína de APM (>150 kDa se vio afectado por la presencia de detergente como el Tween 20 y Empigen BB. Los lavados con Tween 20 constituyeron los pasos más importantes en la renaturalización de los sitios de unión de la IgG a las PME

  9. Agentes dopaminérgicos e o tratamento da disfunção erétil

    Directory of Open Access Journals (Sweden)

    Neves Gilda

    2004-01-01

    Full Text Available The understanding of the scientific basis of the erectile function expanded rapidly the range of therapies for treating erectile dysfunction in recent years. This article reviews the role of dopamine on the erection mechanisms and its importance for new pro-erectile drug design. The ability of dopaminergic agents to elicit penile erection has been described since 1975 and successively confirmed by numerous studies. The development of apomorphine SL (dopaminergic non selective agonist to enhance erectile function represents a new pharmacological approach to the management of erectile dysfunction using CNS drugs. The search for selective D4 dopaminergic agents is being explored by some research groups and pharmaceutical companies.

  10. Causality Statistical Perspectives and Applications

    CERN Document Server

    Berzuini, Carlo; Bernardinell, Luisa

    2012-01-01

    A state of the art volume on statistical causality Causality: Statistical Perspectives and Applications presents a wide-ranging collection of seminal contributions by renowned experts in the field, providing a thorough treatment of all aspects of statistical causality. It covers the various formalisms in current use, methods for applying them to specific problems, and the special requirements of a range of examples from medicine, biology and economics to political science. This book:Provides a clear account and comparison of formal languages, concepts and models for statistical causality. Addr

  11. Agente Comunitário de Saúde: um novo ator no cenário da saúde do Brasil Community Health Agent: a new actor in the Brazilian health scenario

    Directory of Open Access Journals (Sweden)

    Andréa Sabino Filgueiras

    2011-01-01

    Full Text Available O Programa de Agentes Comunitários de Saúde (PACS foi introduzido no Brasil em 1991 como uma tática para o desenvolvimento de atividades relacionadas à prevenção de doenças e educação em saúde. Em 1994, o Ministério da Saúde propôs o Programa de Saúde da Família (PSF como estratégia de reestruturação da atenção à saúde. Essas propostas introduzem, no cenário da saúde, um novo ator, o Agente Comunitário de Saúde (ACS, desempenhando importante papel na atenção básica, ao agir como um elo entre famílias, usuários e serviço de saúde. O estudo toma como objeto o trabalho desenvolvido pelos ACS em uma unidade do PSF do município de Volta Redonda-RJ. Tem como objetivo discutir os aspectos facilitadores e limitantes das atividades designadas aos ACS. Trata-se de uma pesquisa do tipo descritiva, com abordagem qualitativa. A análise de dados se deu por categorias analíticas, que emergiram a partir dos dados encontrados nas entrevistas. Após a apreciação dos dados, pôde-se constatar que os ACS do PSF de Volta Redonda ainda não recebem formação destinada à execução de suas atividades e que consideram a experiência prática como o principal motor para o desempenho delas. O trabalho em equipe é reconhecido como espaço de circulação de saberes científicos e o saber popular como mediador entre a equipe e a população. Os ACS têm como eixo de trabalho a visita domiciliar, focada principalmente na doença.The Community Health Agents Program (PACS was created in 1991 as a strategy to implement the SUS, developing activities related to prevention and health education. In 1994, the Health Ministry proposed the Family Health Program (PSF as a strategy for restructuring the dominant care model. With the emergence of these two programs, there is the emergence of a new actor in the health scenario, the Community Health Agent (ACS. This actor plays an important role in basic care, acting as a link between families

  12. Experimental strabismus surgery using triamcinolone: outcomes and effects on inflammatory response Utilização da triancinolona como agente modulador da resposta inflamatória na cirurgia de estrabismo em coelhos

    Directory of Open Access Journals (Sweden)

    Luis Eduardo Morato Rebouças de Carvalho

    2007-03-01

    Full Text Available PURPOSE: To evaluate the efficiency of triamcinolone (TRI in limiting the postoperative inflammatory response and scarring after strabismus surgery. METHODS: A prospective, two-stage, masked, controlled trial was conducted. In the first stage, the inflammatory response at the extraocular muscle reattachment site was analyzed after superior rectus recession in ten rabbits. In the second stage, TRI (40 mg/ml was applied during surgery to the eyes of 16 rabbits with superior rectus recession. As a control, contralateral eyes were treated with physiological saline. Fifteen days later, exenteration was performed, and the sites of muscle reattachment were processed for histological examinations. The sums of the areas of the granulomas in the extraocular muscle reattachment sites of control and treated eyes were compared. RESULT: There was a preliminary inhibition effect of TRI on the inflammatory response of treated eyes compared with that of control eyes. CONCLUSIONS: In the conditions of conducting this study the introperative use of TRI was effective in controlling the postoperative inflammatory response in rabbit eyes after extraocular muscle surgery.OBJETIVO: Avaliar a eficiência da triancinolona (TRI como agente modulador da resposta inflamatória e cicatricial em coelhos submetidos à cirurgia de estrabismo. MÉTODOS: Foi realizado estudo prospectivo, mascarado, em dois estágios. No primeiro estágio 10 coelhos foram submetidos a retrocesso do músculo reto superior em ambos os olhos, aplicando-se triancinolona (40 mg/ml em um dos olhos e como controle, solução salina nos olhos contralaterais. Quinze dias e trinta dias após, os animais foram exenterados e o material do sítio de reinserção muscular foi submetido à análise qualitativa e quantitativa. No segundo estágio, com incrementação da agressão cirúrgica, 16 coelhos foram submetidos aos mesmos procedimentos com exenteração e análise dos tecidos após 15 dias. RESULTADO

  13. O direito à vida no contexto do aborto e da pesquisa com células-tronco embrionárias: disputas de agentes e valores religiosos em um estado laico

    Directory of Open Access Journals (Sweden)

    Naara Luna

    2013-01-01

    Full Text Available O artigo aborda o debate público sobre o direito à vida no contexto da autorização da pesquisa com células-tronco embrionárias e no debate sobre o aborto, enfocando a participação de atores religiosos e seus valores. Serão examinados o debate legislativo e judiciário da Lei de Biossegurança e a audiência pública da ADPF 54, referente à antecipação de parto de anencéfalo. Esta pesquisa documental analisa a transcrição da audiência pública da ADPF 54, e os registros do processo legislativo no Congresso Nacional e da ADI 3510 no Supremo Tribunal Federal. Os resultados revelam, além da centralidade do argumento do valor da vida, a diversidade na atuação dos agentes religiosos, com hegemonia da Igreja Católica e a emergência de evangélicos e espíritas.

  14. Inferring deterministic causal relations

    CERN Document Server

    Daniusis, Povilas; Mooij, Joris; Zscheischler, Jakob; Steudel, Bastian; Zhang, Kun; Schoelkopf, Bernhard

    2012-01-01

    We consider two variables that are related to each other by an invertible function. While it has previously been shown that the dependence structure of the noise can provide hints to determine which of the two variables is the cause, we presently show that even in the deterministic (noise-free) case, there are asymmetries that can be exploited for causal inference. Our method is based on the idea that if the function and the probability density of the cause are chosen independently, then the distribution of the effect will, in a certain sense, depend on the function. We provide a theoretical analysis of this method, showing that it also works in the low noise regime, and link it to information geometry. We report strong empirical results on various real-world data sets from different domains.

  15. Causal Inference and Developmental Psychology

    Science.gov (United States)

    Foster, E. Michael

    2010-01-01

    Causal inference is of central importance to developmental psychology. Many key questions in the field revolve around improving the lives of children and their families. These include identifying risk factors that if manipulated in some way would foster child development. Such a task inherently involves causal inference: One wants to know whether…

  16. Re-thinking local causality

    NARCIS (Netherlands)

    Friederich, Simon

    2015-01-01

    There is widespread belief in a tension between quantum theory and special relativity, motivated by the idea that quantum theory violates J. S. Bell's criterion of local causality, which is meant to implement the causal structure of relativistic space-time. This paper argues that if one takes the es

  17. Expert Causal Reasoning and Explanation.

    Science.gov (United States)

    Kuipers, Benjamin

    The relationship between cognitive psychologists and researchers in artificial intelligence carries substantial benefits for both. An ongoing investigation in causal reasoning in medical problem solving systems illustrates this interaction. This paper traces a dialectic of sorts in which three different types of causal resaoning for medical…

  18. O contexto da formação dos agentes comunitários de saúde no Brasil

    Directory of Open Access Journals (Sweden)

    Daniela França de Barros

    2010-01-01

    Full Text Available Este estudio tuvo como objetivo identificar y describir el proceso histórico de la formación profesional de los agentes comunitarios de salud, mediante el análisis de documentos relativos a la formación técnica en salud. Es una investigación documental realizada en documentos normativos e instrumentales en los registros administrativos y de gestión del Departamento de Atención Primaria, con investigación bibliográfica en las bases de datos Medline y LILACS, de publicaciones orientadas a la política de formación profesional, en el período de 1986 a 2006, y de lectura con análisis temático. En respuesta a las demandas políticas y económicas, el agente comunitario de salud se convirtió en profesión en 2002. Sus funciones fueron ampliadas, motivo por el cual, en 2006 ya había en Brasil más de 200 mil profesionales trabajando según el nuevo reglamento: la Ley 11.350, que revocó la ley anterior. El agente comunitario se convirtió en un elemento importante para la promoción de cambios en el modelo asistencial y el fortalecimiento de la atención primaria en salud.

  19. The Visual Causality Analyst: An Interactive Interface for Causal Reasoning.

    Science.gov (United States)

    Wang, Jun; Mueller, Klaus

    2016-01-01

    Uncovering the causal relations that exist among variables in multivariate datasets is one of the ultimate goals in data analytics. Causation is related to correlation but correlation does not imply causation. While a number of casual discovery algorithms have been devised that eliminate spurious correlations from a network, there are no guarantees that all of the inferred causations are indeed true. Hence, bringing a domain expert into the casual reasoning loop can be of great benefit in identifying erroneous casual relationships suggested by the discovery algorithm. To address this need we present the Visual Causal Analyst-a novel visual causal reasoning framework that allows users to apply their expertise, verify and edit causal links, and collaborate with the causal discovery algorithm to identify a valid causal network. Its interface consists of both an interactive 2D graph view and a numerical presentation of salient statistical parameters, such as regression coefficients, p-values, and others. Both help users in gaining a good understanding of the landscape of causal structures particularly when the number of variables is large. Our framework is also novel in that it can handle both numerical and categorical variables within one unified model and return plausible results. We demonstrate its use via a set of case studies using multiple practical datasets. PMID:26529703

  20. Sequential Extensions of Causal and Evidential Decision Theory

    OpenAIRE

    Everitt, Tom; Leike, Jan; Hutter, Marcus

    2015-01-01

    Moving beyond the dualistic view in AI where agent and environment are separated incurs new challenges for decision making, as calculation of expected utility is no longer straightforward. The non-dualistic decision theory literature is split between causal decision theory and evidential decision theory. We extend these decision algorithms to the sequential setting where the agent alternates between taking actions and observing their consequences. We find that evidential decision theory has t...

  1. Ratoon stunting disease of sugarcane: isolation of the causal bacterium.

    Science.gov (United States)

    Davis, M J; Gillaspie, A G; Harris, R W; Lawson, R H

    1980-12-19

    A small coryneform bacterium was consistently isolated from sugarcane with ratoon stunting disease and shown to be the causal agent. A similar bacterium was isolated from Bermuda grass. Both strains multiplied in sugarcane and Bermuda grass, but the Bermuda grass strain did not incite the symptoms of ratoon stunting disease in sugarcane. Shoot growth in Bermuda grass was retarded by both strains. PMID:17817853

  2. A atuação do agente comunitário de saúde na promoção da saúde e na prevenção de doenças

    OpenAIRE

    Maria Rizoneide Negreiros Araújo; Raquel Silva Assunção

    2004-01-01

    O artigo trata das ações desenvolvidas pelo agente comunitário de saúde - ACS no Programa de Saúde da Família de Divinópolis - MG, fazendo uma relação de tuação nos campos da Promoção da Saúde e da Prevenção de Doenças, tomando como referencial a I Conferência Internacional sobre Promoção da Saúde, realizada no Canadá, em 1986. A pesquisa de campo foi realizada com questionário, observação direta e entrevista com os ACS. De abordagem qualitativa em que as concepções e expressões dos sujeitos ...

  3. ["Karoshi" and causal relationships].

    Science.gov (United States)

    Hamajima, N

    1992-08-01

    This paper aims to introduce a measure for use by physicians for stating the degree of probable causal relationship for "Karoshi", ie, a sudden death from cerebrovascular diseases or ischemic heart diseases under occupational stresses, as well as to give a brief description for legal procedures associated with worker's compensation and civil trial in Japan. It is a well-used measure in epidemiology, "attributable risk percent (AR%)", which can be applied to describe the extent of contribution to "Karoshi" of the excess occupational burdens the deceased worker was forced to bear. Although several standards such as average occupational burdens for the worker, average occupational burdens for an ordinary worker, burdens in a nonoccupational life, and a complete rest, might be considered for the AR% estimation, the average occupational burdens for an ordinary worker should normally be utilized as a standard for worker's compensation. The adoption of AR% could be helpful for courts to make a consistent judgement whether "Karoshi" cases are compensatable or not. PMID:1392028

  4. O trabalho no cárcere: reflexões acerca da saúde do agente penitenciário

    Directory of Open Access Journals (Sweden)

    Caroline Raquele Jaskowiak

    2015-04-01

    Full Text Available RESUMO Objetivo: conhecer as condições de trabalho de agentes penitenciários e os reflexos do exercício da atividade laboral em sua saúde. Método: pesquisa descritiva, qualitativa. Os dados foram coletados por meio de entrevista aberta com agentes de um presídio regional e submetidos a análise de conteúdo na modalidade temática. Resultados: os resultados revelaram condições de trabalho insatisfatórias por deficiência de recursos materiais e descaso do poder público com as questões inerentes à ressocialização do apenado, resultando em exposição aos riscos psicossociais, insatisfação e desgaste emocional dos trabalhadores. Conclusão: investimentos na segurança dos trabalhadores podem contribuir para a promoção de sua saúde.

  5. Chestnut and lemon balm based ingredients as natural preserving agents of the nutritional profile in matured "Serra da Estrela" cheese.

    Science.gov (United States)

    Carocho, Márcio; Barreira, João C M; Bento, Albino; Fernández-Ruiz, Virginia; Morales, Patricia; Ferreira, Isabel C F R

    2016-08-01

    Chestnut flowers, lemon balm plants and their decoctions were incorporated into "Serra da Estrela" cheese, to assess their potential to preserve its nutritional properties and provide new foodstuffs. The analyses were carried out after the normal ripening period of 1month and after 6months of storage. The most abundant nutrients were proteins and fats. The most abundant minerals were Ca and Na, while C16:0 and C18:1 were the main fatty acids. Saturated fatty acids were the most abundant, followed by the monounsaturated. Moisture seemed to be lower in the samples with the plants incorporated. The dried plants, when incorporated, seemed to be more efficient as preservers then the decoctions, although these better preserved the proteins. These plants can be regarded as promising natural preservers in foodstuffs cheese, given the preservation of key parameters and the slight impact on the nutritional value. PMID:26988492

  6. Principal stratification in causal inference.

    Science.gov (United States)

    Frangakis, Constantine E; Rubin, Donald B

    2002-03-01

    Many scientific problems require that treatment comparisons be adjusted for posttreatment variables, but the estimands underlying standard methods are not causal effects. To address this deficiency, we propose a general framework for comparing treatments adjusting for posttreatment variables that yields principal effects based on principal stratification. Principal stratification with respect to a posttreatment variable is a cross-classification of subjects defined by the joint potential values of that posttreatment variable tinder each of the treatments being compared. Principal effects are causal effects within a principal stratum. The key property of principal strata is that they are not affected by treatment assignment and therefore can be used just as any pretreatment covariate. such as age category. As a result, the central property of our principal effects is that they are always causal effects and do not suffer from the complications of standard posttreatment-adjusted estimands. We discuss briefly that such principal causal effects are the link between three recent applications with adjustment for posttreatment variables: (i) treatment noncompliance, (ii) missing outcomes (dropout) following treatment noncompliance. and (iii) censoring by death. We then attack the problem of surrogate or biomarker endpoints, where we show, using principal causal effects, that all current definitions of surrogacy, even when perfectly true, do not generally have the desired interpretation as causal effects of treatment on outcome. We go on to forrmulate estimands based on principal stratification and principal causal effects and show their superiority. PMID:11890317

  7. Classical planning and causal implicatures

    DEFF Research Database (Denmark)

    Blackburn, Patrick Rowan; Benotti, Luciana

    In this paper we motivate and describe a dialogue manager (called Frolog) which uses classical planning to infer causal implicatures. A causal implicature is a type of Gricean relation implicature, a highly context dependent form of inference. As we shall see, causal implicatures are important for...... generate clarification requests"; as a result we can model task-oriented dialogue as an interactive process locally structured by negotiation of the underlying task. We give several examples of Frolog-human dialog, discuss the limitations imposed by the classical planning paradigm, and indicate the...

  8. Functional equations with causal operators

    CERN Document Server

    Corduneanu, C

    2003-01-01

    Functional equations encompass most of the equations used in applied science and engineering: ordinary differential equations, integral equations of the Volterra type, equations with delayed argument, and integro-differential equations of the Volterra type. The basic theory of functional equations includes functional differential equations with causal operators. Functional Equations with Causal Operators explains the connection between equations with causal operators and the classical types of functional equations encountered by mathematicians and engineers. It details the fundamentals of linear equations and stability theory and provides several applications and examples.

  9. Influência dos agentes clareadores e um refrigerante a base de cola na microdureza do esmalte dental e a ação da saliva na superfície tratada = Influence of bleaching agents and a carbonated soft drink on dental enamel microhardness as well as the artificial saliva effect on the treated surface

    OpenAIRE

    Araújo, Rodrigo Maximo de; Torres, Carlos Rocha Gomes; de Araújo, Maria Amélia Máximo

    2006-01-01

    O objetivo deste estudo foi avaliar os efeitos de três agentes clareadores e uma bebida carbonatada, à base de cola, sobre a microdureza do esmalte dental, assim como os efeitos da saliva artificial sobre o esmalte tratado com estes agentes. Foram utilizados quarenta dentes incisivos bovinos embutidos em resina acrílica. As amostras foram avaliadas em microdurômetro (Future Tech FM 700) após a divisão em quatro grupos, uma leitura inicial da microdureza serviu como controle do experimento: Gr...

  10. Análise da Relação Causal entre Imagem, Qualidade, Satisfação e Fidelidade: um estudo sobre a percepção do turista nacional no destino turístico Natal-RN

    Directory of Open Access Journals (Sweden)

    Sérgio Marques Júnior

    2011-01-01

    Full Text Available O objetivo principal do estudo é analisar a relação causal existente entre a qualidade, a satisfação, a fidelidade e a imagem de destinos. Para tanto, se realizou um estudo exploratório-descritivo, do tipo Survey, com enfoque analítico quantitativo. A coleta de dados foi realizada através de questionário aplicado junto aos turistas nacionais no Aeroporto Internacional Augusto Severo e na Rodoviária da Cidade do Natal, principais locais de entrada e saída de turistas no local. A composição amostral foi aleatória simples chegando-se ao número final de 400 turistas entrevistados. Dentre os principais resultados, observou-se que são nove as dimensões da percepção de qualidade de destinos de Sol e Praia, ou seja, Praias e Facilidades, Equipamentos Públicos, Alimentos e Bebidas, Serviços de Transportes, Equipamentos do Hotel, Serviços do Hotel, Entretenimento e Atrativos, Acesso ao Hotel e Hospitalidade. Concluiu-se que a imagem exerce influência forte e direta tanto no processo de satisfação do consumidor quanto no de fidelização. As dimensões da qualidade encontradas também se apresentaram como fortes influenciadoras de ambos os fatores, sendo que a satisfação influencia de forma direta a fidelização ao destino.

  11. Identificacion de marcadores genéticos del agente causal del marchitamiento del clavel fusarium oxysporum f.sp. dianthi mediante amplificacion arbitraria de fragmentos polimórficos de adn

    OpenAIRE

    Arbeláez G.; Hernández J.; Junca H.; Posada M.; Portillo P. Del

    2011-01-01

    La técnica de Amplificación Arbitraria de Fragmentos Polimórficos de ADN (RAPD) fue utilizada para identificar marcadores genéticos útiles para el desarrollo de un método diagnóstico para Fusarium oxysporum f.sp. dianthi, el agente etiológico de la enfermedad del marchitamiento del clavel. Con el fin de identificar fragmentos genéticos característicos de este patógeno, un total de 18 aislados diferentes, provenientes de diferentes lugares del mundo y 17 cepas de F. oxysporum de otras formas e...

  12. On causality of extreme events

    CERN Document Server

    Zanin, Massimiliano

    2016-01-01

    Multiple metrics have been developed to detect causality relations between data describing the elements constituting complex systems, all of them considering their evolution through time. Here we propose a metric able to detect causality within static data sets, by analysing how extreme events in one element correspond to the appearance of extreme events in a second one. The metric is able to detect both linear and non-linear causalities; to analyse both cross-sectional and longitudinal data sets; and to discriminate between real causalities and correlations caused by confounding factors. We validate the metric through synthetic data, dynamical and chaotic systems, and data representing the human brain activity in a cognitive task.

  13. Heat treatment and gamma radiation on the control of Colletotrichum gloeosporioides (Penz.) Penz. et Sacc., causal agent of the papaya fruits (Carica papaya L.) anthracnose; Tratamento termico e radiacao gamma no controle de Colletotrichum gloeosporioides (PENZ.) PENTZ et SACC., agente causal da antracnose em frutos de mamoeiro (Carica papaya L.)

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Tanni Maria Werneck da

    1988-12-01

    For controlling papaya anthracnose on stored fruits the effect of heat treatment and gamma radiation on Colletotrichum gloeosporioides was studied in vitro and in vivo. Some physiological studies with four isolades of C. gloeosporioides from papaya fruits concerning the best conditions for mycelial growth and sporulation were also performed. The results showed that the best conditions for isolates development in BDA were: temperature between 25 and 27{sup 0} C for mycelium radial growth; between 27 and 30{sup 0} C under (12 hours alternating periods of fluorescent). (author). 131 refs., 9 figs., 33 tabs.

  14. Efeito do extrato de alho na quebra de dormência de gemas de videiras e no controle in vitro do agente causal da antracnose (Elsinoe ampelina Shear Effect of garlic extract on bud break of grapevines and in vitro control of causal agent of antracnose (Elsinoe ampelina Shear

    Directory of Open Access Journals (Sweden)

    Renato Vasconcelos Botelho

    2009-03-01

    Full Text Available Considerando a redução ou eliminação do uso de substâncias sintéticas que preconizam os sistemas sustentáveis de produção de frutas, este trabalho teve como objetivo a busca de novas alternativas para a quebra de dormência e o controle de doenças em videiras. Estacas de videira contendo uma gema foram pulverizadas com os seguintes tratamentos: 1 testemunha; 2 OV (óleo vegetal 1%; 3 extrato de alho (EA 3%; 4 EA 3% + OV 1%. Posteriormente, as estacas foram mantidas em câmara de crescimento (25±2.5ºC por 56 dias. O único tratamento que estimulou a brotação das estacas de videira cv. Isabel Precoce foi o EA 3% + OV 1%, que atingiu 35% de brotação, diferindo estatisticamente dos tratamentos- testemunha (12,5%, OV 1% (17,5% e EA 3% (15,0%. Provavelmente, o estádio de endodormência profunda das gemas, após apenas 90 horas de frio ( Considering the reduction or elimination of synthetic compounds used in sustainable fruit production systems, this work aimed to search for new alternatives for bud break dormancy and diseases control in grapevines. Single-bud cuttings of grapevines were sprayed with the following treatments: 1 control, 2 1% SO (soybean oil, 3 3% GE (garlic extract, 4 3% GE + 1% SO. After that, the cuttings were kept in a growth chamber (25±2.5ºC for 56 days. The unique treatment that stimulated sprouting of grapevines cv. Isabel Precoce was 3% GE + 1% S, that reached 35% sprouting, differing statistically from the control (12.5%, 1% SO (17.5% and 3% GE (15.0%. Probably, the stage of deep endodormancy of buds, after only 90 chilling hours (< 7.0ºC, avoided better results of bud breaks treatments. Three experiments were carried out in vitro, with different garlic extract doses aiming to evaluate the control of the fungus Elsinoe ampelina. In all trials, there were quadratic effects on mycelial growth, without differences between garlic extract treatments, evidencing its fungicide effect, even for the lowest dose of 0.0615% GE.

  15. Causal reasoning with mental models

    OpenAIRE

    Khemlani, Sangeet S.; Barbey, Aron K.; Johnson-Laird, Philip N

    2014-01-01

    This paper outlines the model-based theory of causal reasoning. It postulates that the core meanings of causal assertions are deterministic and refer to temporally-ordered sets of possibilities: A causes B to occur means that given A, B occurs, whereas A enables B to occur means that given A, it is possible for B to occur. The paper shows how mental models represent such assertions, and how these models underlie deductive, inductive, and abductive reasoning yielding explanations. It reviews e...

  16. Consciousness and the "Causal Paradox"

    OpenAIRE

    Velmans, Max

    1996-01-01

    Viewed from a first-person perspective consciousness appears to be necessary for complex, novel human activity - but viewed from a third-person perspective consciousness appears to play no role in the activity of brains, producing a "causal paradox". To resolve this paradox one needs to distinguish consciousness of processing from consciousness accompanying processing or causing processing. Accounts of consciousness/brain causal interactions switch between first- and third-person perspectives...

  17. Realist Magic : Objects, Ontology, Causality

    OpenAIRE

    Morton, Timothy

    2013-01-01

    Object-oriented ontology offers a startlingly fresh way to think about causality that takes into account developments in physics since 1900. Causality, argues, Object Oriented Ontology (OOO), is aesthetic. In this book, Timothy Morton explores what it means to say that a thing has come into being, that it is persisting, and that it has ended. Drawing from examples in physics, biology, ecology, art, literature and music, Morton demonstrates the counterintuitive yet elegant explanatory power of...

  18. Correlation Measure Equivalence in Dynamic Causal Structures

    CERN Document Server

    Gyongyosi, Laszlo

    2016-01-01

    We prove an equivalence transformation between the correlation measure functions of the causally-unbiased quantum gravity space and the causally-biased standard space. The theory of quantum gravity fuses the dynamic (nonfixed) causal structure of general relativity and the quantum uncertainty of quantum mechanics. In a quantum gravity space, the events are causally nonseparable and all time bias vanishes, which makes it no possible to use the standard causally-biased entropy and the correlation measure functions. Since a corrected causally-unbiased entropy function leads to an undefined, obscure mathematical structure, in our approach the correction is made in the data representation of the causally-unbiased space. We prove that the standard causally-biased entropy function with a data correction can be used to identify correlations in dynamic causal structures. As a corollary, all mathematical properties of the causally-biased correlation measure functions are preserved in the causally-unbiased space. The eq...

  19. Tolerância a agente curarizante provocada pela administração repetida da droga

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Zanini

    1974-03-01

    Full Text Available Baseados em teoria discutível segundo a qual a miastenia grave é provocada pela presença no sangue de substância curarizante liberada pelo timo, tentou-se reproduzir um modelo experimental. Foram utilizados 40 ratos, criados nas mesmas condições, nascidos no mesmo dia, pesando ao redor de 350 g e divididos em 4 grupos: o Grupo I não foi manuseado; no Grupo II foi injetada solução fisiológica, 1 ml i.p. durante 6 semanas; no Grupo III foi injetada a dimetil tubocurarina (DMT 2,8 mcg/kg i.p., durante o mesmo tempo; no Grupo IV 14 mcg/kg da mesma droga foram injetados i.p. Uma semana após a última injeção i.p. os ratos, anestesiados, foram preparados para registro neuromuscular. O nervo ciático foi estimulado nas freqüências de 0,33 pulsos/seg, 70 pulsos/seg (séries de 10 pulsos a intervalos de 3 seg, 70 pulsos/seg (mantidos por 15 seg e novamente 0,33 pulsos/seg logo após a tetanização. A dose curarizante de DMT foi determinada por uma "terceira parte cega" quando 80% do bloqueio era alcançado. Quando apenas 10 estímulos em alta freqüência foram aplicados ao nervo, foi observada diferença significativa (p<0.05 na resposta: Grupo I, 46,50 ± 20,00 g+; Grupo II, 55,25 ± 11,33 g+; Grupo III, 37,25 ± 10,77 g+; Grupo IV 37,00 ± 12,74 g+. Diferenças significantes de força muscular foram também observadas após a tetanização mantida: Grupo I, 79,00 ± 16,21 g+; Grupo II, 76,75 ± 15,23 g+; Grupo III, 59,12 ± 17,38 g+; Grupo IV, 61,62 ± 14,74 g. Doses significamente mais altas de curare i.v. foram necessárias no grupo injetado diariamente com a maior dose de curare do que em qualquer dos outros grupos (p < 0,01: Grupo I, 3,62 ± 1,17 mcg/kg; Grupo II, 3,69 ± 1,21 mcg/kg; Grupo III, 4,01 ± 0,80 mcg/kg; Grupo IV, 5,48 ± 1,40 mcg/kg. Tais resultados mostram que a administração crônica do curare leva ao enfraquecimento físico e hiposensibilidade à droga. Isto sugere que embora a existência de subst

  20. Causality, causality, causality: the view of education inputs and outputs from economics

    OpenAIRE

    Lisa Barrow; Cecilia Elena Rouse

    2005-01-01

    Educators and policy makers are increasingly intent on using scientifically-based evidence when making decisions about education policy. Thus, education research today must necessarily be focused on identifying the causal relationships between education inputs and student outcomes. In this paper we discuss methodologies for estimating the causal effect of resources on education outcomes; we also review what we believe to be the best evidence from economics on a few important inputs: spending,...

  1. Influência do agente de união na resistência ao cisalhamento da interface titânio/polímero de vidro Bonding agent influence on shear bond strength of titanium/polyglass interface

    Directory of Open Access Journals (Sweden)

    Denise Kanashiro Oyafuso

    2003-09-01

    Full Text Available Há poucas informações em relação à efetividade da união entre compósitos e superfícies metálicas. Este estudo avaliou a influência de dois agentes de união na resistência ao cisalhamento da interface formada pelo titânio comercialmente puro (Ti cp e um compósito (Artglass/ Heraeus Kulzer. Vinte estruturas metálicas (4mm de diâmetro e 5mm de altura de titânio grau 1 foram fundidas, jateadas com partículas de óxido de alumínio (250ìm e separadas em dois grupos. Para cada grupo foi utilizado um agente de união (Sistema Siloc-Pre ou Retention Flow como procedimento anterior à aplicação do material opaco. Sobre este foram aplicados camadas do polímero referente à dentina com o auxílio de uma matriz de teflon. A manipulação e polimerização foram realizadas de acordo com as recomendações do fabricante. Os corpos-de-prova foram armazenados em água destilada por 24 horas à 37ºC e termociclados (5º e 55ºC/ 500ciclos. O teste de resistência ao cisalhamento foi realizado em uma máquina de ensaios universal (Instron com velocidade de 5mm/min. Os dados foram tratados estatisticamente pela Análise de Variância one-way (á=0,5. Os resultados indicaram que o sistema adesivo Retention Flow foi estatisticamente melhor do que o Siloc, com médias de 20,74MPa e 11,65MPa, respectivamente. Foi possível concluir que o sistema de união influenciou na adesão entre o titânio grau I e o polímero de vidro estudado.There is little information regarding bond strengths of polyglass to metal alloys. This study evaluated the influence of bonding system on shear bond strength of a composite resin (Artglass/Heraeus Kulzer to cast titanium (Ti. Twenty metallic structures (4mm in diameter, 5mm thick of titanium grade I were cast shaped and abraded with 250mm aluminum oxide and separated into two groups. For each group was applied one bonding system (Siloc or Retention Flow before opaque and dentin polymer superposition. This procedure

  2. Variability of the wheat powdery mildew pathogen Blumeria graminis f. sp. tritici in the 2003 crop season Variabilidade do agente causal de oídio de trigo, Blumeria graminis f. sp. tritici, na safra 2003

    Directory of Open Access Journals (Sweden)

    Leila M. Costamilan

    2005-08-01

    ênicas de B. graminis f. sp. tritici coletadas no Brasil e a efetividade de genes de resistência de trigo a oídio, na safra 2003. Plantas de trigo da série diferencial para raças foram inoculadas com cada isolado monopustular. Foram identificadas 31 combinações de genes efetivos e inefetivos para resistência. Para as amostras da população de oídio estudada, o gene de resistência de trigo Pm4a+... permaneceu totalmente efetivo para todos os isolados, e o gene Pm6 foi altamente efetivo (abaixo de 10% de suscetibilidade, enquanto os genes Pm3a e Pm8 foram totalmente inefetivos (suscetíveis a todos os isolados. Os genes Pm1, 2, 4a, 1+? e 2+Mld foram medianamente efetivos para a maioria dos isolados (entre 10% e 49% de suscetibilidade, e Pm3c, D1 e D2 mostraram baixa efetividade (acima de 50% de suscetibilidade. A fórmula de virulência Pm1, 3c, 4a, 6, 1+?, 2+Mld, 4a+..., D2 (genes efetivos / 2, 3a, 8, D1 (genes inefetivos foi a mais freqüentemente encontrada, respondendo por 15% das ocorrências. O número mais freqüente de genes inefetivos foi sete, variando entre três e dez.

  3. Causality in physiological signals.

    Science.gov (United States)

    Müller, Andreas; Kraemer, Jan F; Penzel, Thomas; Bonnemeier, Hendrik; Kurths, Jürgen; Wessel, Niels

    2016-05-01

    Health is one of the most important non-material assets and thus also has an enormous influence on material values, since treating and preventing diseases is expensive. The number one cause of death worldwide today originates in cardiovascular diseases. For these reasons the aim of understanding the functions and the interactions of the cardiovascular system is and has been a major research topic throughout various disciplines for more than a hundred years. The purpose of most of today's research is to get as much information as possible with the lowest possible effort and the least discomfort for the subject or patient, e.g. via non-invasive measurements. A family of tools whose importance has been growing during the last years is known under the headline of coupling measures. The rationale for this kind of analysis is to identify the structure of interactions in a system of multiple components. Important information lies for example in the coupling direction, the coupling strength, and occurring time lags. In this work, we will, after a brief general introduction covering the development of cardiovascular time series analysis, introduce, explain and review some of the most important coupling measures and classify them according to their origin and capabilities in the light of physiological analyses. We will begin with classical correlation measures, go via Granger-causality-based tools, entropy-based techniques (e.g. momentary information transfer), nonlinear prediction measures (e.g. mutual prediction) to symbolic dynamics (e.g. symbolic coupling traces). All these methods have contributed important insights into physiological interactions like cardiorespiratory coupling, neuro-cardio-coupling and many more. Furthermore, we will cover tools to detect and analyze synchronization and coordination (e.g. synchrogram and coordigram). As a last point we will address time dependent couplings as identified using a recent approach employing ensembles of time series. The

  4. Formação de Agentes Comunitárias de Saúde para o enfrentamento da violência de gênero: contribuições da Educação Popular e da pedagogia feminista

    Directory of Open Access Journals (Sweden)

    Sônia Maria Dantas Berger

    2014-12-01

    Full Text Available Apresentam-se resultados parciais de uma pesquisa-ação que investigou a violência de gênero na Estratégia Saúde da Família, com especial atenção sobre as Agentes Comunitárias de Saúde (ACSs, atores estratégicos na atenção a mulheres em situação de violência. Dentre as atividades de pesquisa e intervenção desenvolvidas, incluem-se oficinas com as ACSs para a discussão dialogada dos resultados da pesquisa. Tomando-se como referência os pressupostos da Educação Popular e da pedagogia feminista, conclui-se que as oficinas representaram um valioso recurso político-pedagógico, permitindo uma fecunda interação dialógica entre academia e serviços de saúde e oferecendo visibilidade e reconhecimento às vozes e às ricas experiências de vida e trabalho das ACSs contribuindo, assim, para uma construção compartilhada do conhecimento que fortalece práxis comprometidas com transformações na assistência à saúde e nas relações sociais mais amplas.

  5. Hierarchical organisation of causal graphs

    International Nuclear Information System (INIS)

    This paper deals with the design of a supervision system using a hierarchy of models formed by graphs, in which the variables are the nodes and the causal relations between the variables of the arcs. To obtain a representation of the variables evolutions which contains only the relevant features of their real evolutions, the causal relations are completed with qualitative transfer functions (QTFs) which produce roughly the behaviour of the classical transfer functions. Major improvements have been made in the building of the hierarchical organization. First, the basic variables of the uppermost level and the causal relations between them are chosen. The next graph is built by adding intermediary variables to the upper graph. When the undermost graph has been built, the transfer functions parameters corresponding to its causal relations are identified. The second task consists in the upwelling of the information from the undermost graph to the uppermost one. A fusion procedure of the causal relations has been designed to compute the QFTs relevant for each level. This procedure aims to reduce the number of parameters needed to represent an evolution at a high level of abstraction. These techniques have been applied to the hierarchical modelling of nuclear process. (authors). 8 refs., 12 figs

  6. Identificacion de marcadores genéticos del agente causal del marchitamiento del clavel fusarium oxysporum f.sp. dianthi mediante amplificacion arbitraria de fragmentos polimórficos de adn

    Directory of Open Access Journals (Sweden)

    Arbeláez G.

    1998-12-01

    Full Text Available La técnica de Amplificación Arbitraria de Fragmentos Polimórficos de ADN (RAPD fue utilizada para identificar marcadores genéticos útiles para el desarrollo de un método diagnóstico para Fusarium oxysporum f.sp. dianthi, el agente etiológico de la enfermedad del marchitamiento del clavel. Con el fin de identificar fragmentos genéticos característicos de este patógeno, un total de 18 aislados diferentes, provenientes de diferentes lugares del mundo y 17 cepas de F. oxysporum de otras formas especiales fueron amplificadas utilizando 15 iniciadores diferentes. Aunque ninguno de los iniciadores empleados en este estudio amplificó una banda común a todas las formas especiales dianthi, el iniciador OPA 17 mostró un patrón de RAPD que permitió la identificación de cuatro grupos polimórficos dentro de este grupo taxonómico. Este mismo iniciador, permitió la discriminación entre aislados de Fusarium oxysporum f.sp. dianthi y cepas de F. oxysporum de otras formas especiales. No se observó una correlación directa entre el patrón de RAPD y las razas reportadas para F. oxysporum f.sp. dianthi, previamente determinadas mediante ensayos biológicos por otros grupos de investigadores. Los análisis de hibridación molecular con fragmentos escogidos de estos patrones de RAPD, permitieron el reconocimiento selectivo de los cuatro grupos descritos. Los fragmentos genómicos identificados, son candidatos para el desarrollo de un  sistema diagnóstico por PCR para este patógeno del clavel.

  7. The role of hyperbaric oxygen therapy (HOT as an otoprotection agent against cisplatin ototoxicity Efeito otoprotetor da oxigenoterapia hiperbárica na toxicidade causada pela cisplatina

    Directory of Open Access Journals (Sweden)

    Camila C. Yassuda

    2008-01-01

    Medicina de Ribeirao Preto da Universidade de São Paulo nos anos de 2005 e 2006. Objetivo: Avaliar o papel da Oxigenoterapia Hiperbárica como agente otoprotector contra a toxicidade de drogas. MÉTODOS: Cobaias albinas divididas em 2 grupos Grupo A: com 5 cobaias (10 cócleas que receberam cisplatina 8,0 mg/kg/dia, via intraperitoneal por 3 dias, submetidas posteriormente a OHB. Grupo B: com 3 cobaias (6 cócleas que receberam cisplatina 8,0 mg/kg/dia, via intraperitoneal por 3 dias. As cobaias foram avaliadas através de otoemissões acústicas (OEA e por microscopia eletrônica de varredura (MEV. Resultados: Encontramos no grupo B perda da função auditiva medida pela OEA e distorção das células ciliares externas a MEV. No grupo A, a MEV as células ciliares externas foram preservadas em sua grande maioria. CONCLUSÃO: Assim podemos supor que a Oxigenoterapia Hiperbárica tem um efeito otoprotetor contra a ototoxicidade induzida pela cisplatina.

  8. Causal reasoning with mental models.

    Science.gov (United States)

    Khemlani, Sangeet S; Barbey, Aron K; Johnson-Laird, Philip N

    2014-01-01

    This paper outlines the model-based theory of causal reasoning. It postulates that the core meanings of causal assertions are deterministic and refer to temporally-ordered sets of possibilities: A causes B to occur means that given A, B occurs, whereas A enables B to occur means that given A, it is possible for B to occur. The paper shows how mental models represent such assertions, and how these models underlie deductive, inductive, and abductive reasoning yielding explanations. It reviews evidence both to corroborate the theory and to account for phenomena sometimes taken to be incompatible with it. Finally, it reviews neuroscience evidence indicating that mental models for causal inference are implemented within lateral prefrontal cortex. PMID:25389398

  9. Causal reasoning with mental models

    Directory of Open Access Journals (Sweden)

    Sangeet eKhemlani

    2014-10-01

    Full Text Available This paper outlines the model-based theory of causal reasoning. It postulates that the core meanings of causal assertions are deterministic and refer to temporally-ordered sets of possibilities: A causes B to occur means that given A, B occurs, whereas A enables B to occur means that given A, it is possible for B to occur. The paper shows how mental models represent such assertions, and how these models underlie deductive, inductive, and abductive reasoning yielding explanations. It reviews evidence both to corroborate the theory and to account for phenomena sometimes taken to be incompatible with it. Finally, it reviews neuroscience evidence indicating that mental models for causal inference are implemented within lateral prefrontal cortex.

  10. Causal Models for Risk Management

    Directory of Open Access Journals (Sweden)

    Neysis Hernández Díaz

    2013-12-01

    Full Text Available In this work a study about the process of risk management in major schools in the world. The project management tools worldwide highlights the need to redefine risk management processes. From the information obtained it is proposed the use of causal models for risk analysis based on information from the project or company, say risks and the influence thereof on the costs, human capital and project requirements and detect the damages of a number of tasks without tribute to the development of the project. A study on the use of causal models as knowledge representation techniques causal, among which are the Fuzzy Cognitive Maps (DCM and Bayesian networks, with the most favorable MCD technique to use because it allows modeling the risk information witho ut having a knowledge base either itemize.

  11. Influência da temperatura do ar de secagem e da concentração de agente carreador sobre as propriedades físico-químicas do suco de açaí em pó Influence of drying air temperature and carrier agent concentration on the physicochemical properties of açai juice powder

    Directory of Open Access Journals (Sweden)

    Renata Valeriano Tonon

    2009-06-01

    Full Text Available A influência da temperatura do ar de secagem e da concentração de agente carreador sobre as propriedades físico-químicas do suco de açaí em pó produzido por spray drying foi avaliada. O processo foi realizado em um mini spray dryer de bancada e maltodextrina 10DE foi utilizada como agente carreador. A temperatura do ar de secagem variou de 138 a 202 °C e a concentração de maltodextrina variou de 10 a 30%. As características analisadas foram: umidade, higroscopicidade, retenção de antocianinas, cor, distribuição do tamanho de partículas e morfologia. O aumento da temperatura resultou em partículas maiores, menos úmidas, mais higroscópicas e com menor retenção de antocianinas, além de provocar uma diminuição do parâmetro de cor L* e do ângulo de tom H*. O aumento na concentração de maltodextrina resultou em partículas maiores e menos higroscópicas, com maior luminosidade (L*, menores valores de C* e maiores valores de H*. Em relação à morfologia, o aumento da temperatura levou à formação de uma maior quantidade de partículas com superfície lisa, fato atribuído à maior transferência de calor e, consequentemente, à formação mais rápida de uma membrana ao redor da gota atomizada.The objective of this work was to study the influence of inlet air temperature and maltodextrin concentration on the physicochemical properties of açai juice powder produced by spray drying. The process was carried out in a mini spray dryer and the maltodextrin 10DE was used as carrier agent. Inlet air temperature varied from 138 to 202 °C and maltodextrin concentration varied from 10 to 30%. The characteristics analyzed were: moisture content, hygroscopicity, anthocyanin retention, color, particle size distribution, and morphology. The increase in the temperature resulted in particles with larger size, less moisture content, more hygroscopy and with lower anthocyanin retention, besides promoting a reduction in the color

  12. On Causality in Dynamical Systems

    CERN Document Server

    Harnack, Daniel

    2016-01-01

    Identification of causal links is fundamental for the analysis of complex systems. In dynamical systems, however, nonlinear interactions may hamper separability of subsystems which poses a challenge for attempts to determine the directions and strengths of their mutual influences. We found that asymmetric causal influences between parts of a dynamical system lead to characteristic distortions in the mappings between the attractor manifolds reconstructed from respective local observables. These distortions can be measured in a model-free, data-driven manner. This approach extends basic intuitions about cause-effect relations to deterministic dynamical systems and suggests a mathematically well defined explanation of results obtained from previous methods based on state space reconstruction.

  13. Cohomology with causally restricted supports

    CERN Document Server

    Khavkine, Igor

    2014-01-01

    De Rham cohomology with spacelike compact and timelike compact supports has recently been noticed to be of importance for understanding the structure of classical and quantum field theories on curved spacetimes. We compute these cohomology groups for globally hyperbolic spacetimes in terms of their standard de Rham cohomologies. The calculation exploits the fact that the de Rham-d'Alambert wave operator can be extended to a chain map that is homotopic to zero and that its causal Green function fits into a convenient exact sequence. This method extends also to the Calabi (or Killing-Riemann-Bianchi) complex and possibly other differential complexes. We also discuss generalized causal structures and functoriality.

  14. Vulnerabilidade e sofrimento no trabalho do agente comunitário de saúde no Programa de Saúde da Família Vulnerabilidad y sufrimiento en el trabajo del agente comunitario de salud en el Programa Salud de la Familia Vulnerability and suffering in the work of a community health agent in the Family Health Program

    Directory of Open Access Journals (Sweden)

    Wânia Regina Veiga Martines

    2007-09-01

    Full Text Available A pesquisa, de natureza qualitativa, teve como núcleo de interesse investigativo as representações e as significações que um grupo de Agentes Comunitários de Saúde (ACSs possui acerca das vulnerabilidades para o sofrimento no trabalho a que estão expostos, assim como as próprias manifestações deste sofrimento ao desempenharem suas ações relativas ao Programa de Saúde da Família (PSF.A entrevista semi-estruturada com um grupo de ACSs, explorou o significado de ser ACS e a percepção da organização do trabalho; a análise foi embasada no referencial teórico-metodológico da hermenêutica e nas teorias relacionadas à psicodinâmica do trabalho. Os achados mostram a existência de uma importante vulnerabilidade ao sofrimento, gerada principalmente pela ideação idealizada da própria prática e pela escassa perspectiva de rearranjo dos ingredientes constitutivos da organização do trabalho, já que este profissional depende de fatores alheios ao seu espectro de alcance, que inclui as limitações do modelo assistencial proposto pelo PSF.La investigación, de naturaleza cualitativa, tuvo como centro de interés un grupo de Agentes Comunitarios de Salud (ACSs sobre las vulnerabilidades para el sufrimiento en el trabajo a que están expuestos, al desempeñar sus acciones profesionales en el Programa Salud de la Familia (PSF.La entrevista semi estructurada exploró el significado de ser ACS y la percepción de la organización del trabajo; el análisis fue efectuado con base al referencial teórico-metodológico de la hermenéutica y de las teorías relacionadas a la psicodinámica del trabajo.Los descubrimientos muestran la existencia de una importante vulnerabilidad al sufrimiento, generada principalmente por la creación de las ideas idealizadas de la propia práctica y por la escasa perspectiva de la disposición de los ingredientes constitutivos de la organización del trabajo, siendo que el profesional depende de factores

  15. Além da informalidade: Entendendo como os fiscais e agentes de desenvolvimento promovem a formalização o crescimento de pequenas e médias empresas

    OpenAIRE

    Almeida, Mansueto

    2008-01-01

    Na maioria dos países em desenvolvimento, o número de pequenas e médias empresas (PMEs) no setor informal tem crescido continuamente na última década em conseqüência do excesso de regulação e da crescente concorrência internacional. Hoje, nesses locais, o grande desafio para formuladores de políticas e agentes de desenvolvimento é conciliar o crescimento econômico com as normas legais. Por um lado, tanto o governo quanto os agentes não-governamentais argumentam que o crescimento econômico de ...

  16. On the Axioms of Causal Set Theory

    CERN Document Server

    Dribus, Benjamin F

    2013-01-01

    This paper offers suggested improvements to the causal sets program in discrete gravity, which treats spacetime geometry as an emergent manifestation of causal structure at the fundamental scale. This viewpoint, which I refer to as the causal metric hypothesis, is summarized by Rafael Sorkin's phrase, "order plus number equals geometry." Proposed improvements include recognition of a generally nontransitive causal relation more fundamental than the causal order, an improved local picture of causal structure, development and use of relation space methods, and a new background-independent version of the histories approach to quantum theory. Besides causal set theory, \\`a la Bombelli, Lee, Meyer, and Sorkin, this effort draws on Isham's topos-theoretic framework for physics, Sorkin's quantum measure theory, Finkelstein's causal nets, and Grothendieck's structural principles. This approach circumvents undesirable structural features in causal set theory, such as the permeability of maximal antichains, studied by ...

  17. Agente Comunitário de Saúde no controle da tuberculose na Atenção Primária à Saúde Agente Comunitario de Salud en el control de la tuberculosis en la Atención Primaria a la Salud The Community Health Agent in the control of tuberculosis in Primary Health Care

    Directory of Open Access Journals (Sweden)

    Juliane de Almeida Crispim

    2012-01-01

    Full Text Available OBJETIVO: Avaliar o desempenho do Agente Comunitário de Saúde (ACS no controle da tuberculose (TB em áreas assistidas pela Estratégia Saúde da Família (ESF, sendo estabelecida uma análise comparativa com os ACSs inscritos nas Unidades Básicas de Saúde (UBS tradicionais. MÉTODOS: Estudo transversal, realizado em um município prioritário para o controle da TB no Estado de São Paulo, com uma amostra mínima de 108 ACSs das ESFs e das UBSs. Para a coleta de dados, utilizou-se um instrumento elaborado para a Atenção Primária à Saúde (APS, adaptado para atenção à TB. RESULTADOS: No que concerne às ações de controle da TB, observou-se que não houve diferenças com significância estatística entre o desempenho dos ACSs das unidades da ESF e os inscritos nas UBSs. CONCLUSÃO: O estudo evidenciou a fragilidade dos ACSs em incorporar na sua prática as ações de controle da TB nas distintas modalidades de APS, apesar do destaque dado à ESF.OBJETIVO: Evaluar el desempeño del Agente Comunitario de Salud (ACS en el control de la tuberculosis (TB en áreas asistidas por la Estrategia Salud de la Familia (ESF, siendo establecido un análisis comparativo con los ACSs inscritos en las Unidades Básicas de Salud (UBS tradicionales. MÉTODOS: Estudio transversal, realizado en un municipio prioritario para el control de la TB en el Estado de Sao Paulo, con una muestra mínima de 108 ACSs de las ESFs y de las UBSs. Para la recolección de los datos se utilizó un instrumento elaborado para la Atención Primaria a la Salud (APS, adaptado para la atención a la TB. RESULTADOS: En lo que concierne a las acciones de control de la TB, se observó que no hubo diferencias con significancia estadística entre el desempeño de los ACSs de las unidades de la ESF y los inscritos en las UBSs. CONCLUSIÓN: En el estudio se evidenció la fragilidad de los ACSs para incorporar en su práctica acciones de control de la TB en las distintas modalidades de

  18. Granger Causality and Unit Roots

    DEFF Research Database (Denmark)

    Rodríguez-Caballero, Carlos Vladimir; Ventosa-Santaulària, Daniel

    2014-01-01

    The asymptotic behavior of the Granger-causality test under stochastic nonstationarity is studied. Our results confirm that the inference drawn from the test is not reliable when the series are integrated to the first order. In the presence of deterministic components, the test statistic diverges...

  19. Causal feedbacks in climate change

    NARCIS (Netherlands)

    Nes, van E.H.; Scheffer, M.; Brovkin, V.; Lenton, T.M.; Ye, H.; Deyle, E.; Sugihara, G.

    2015-01-01

    The statistical association between temperature and greenhouse gases over glacial cycles is well documented1, but causality behind this correlation remains difficult to extract directly from the data. A time lag of CO2 behind Antarctic temperature—originally thought to hint at a driving role for tem

  20. Causal Behaviour on Carter spacetime

    CERN Document Server

    Blanco, Oihane F

    2015-01-01

    In this work we will focus on the causal character of Carter Spacetime (see B. Carter, Causal structure in space-time, Gen. Rel. Grav. 1 4 337-406, 1971). The importance of this spacetime is the following: for the causally best well behaved spacetimes (the globally hyperbolic ones), there are several characterizations or alternative definitions. In some cases, it has been shown that some of the causal properties required in these characterizations can be weakened. But Carter spacetime provides a counterexample for an impossible relaxation in one of them. We studied the possibility of Carter spacetime to be a counterexample for impossible lessening in another characterization, based on the previous results. In particular, we will prove that the time-separation or Lorentzian distance between two chosen points in Carter spacetime is infinite. Although this spacetime turned out not to be the counterexample we were looking for, the found result is interesting per se and provides ideas for alternate approaches to t...

  1. Causality problem in Economic Science

    Directory of Open Access Journals (Sweden)

    JOSÉ LUIS RETOLAZA

    2007-12-01

    Full Text Available The main point of the paper is the problem of the economy to be consider like a science in the most strict term of the concept. In the first step we are going to tackle a presentation about what we understand by science to subsequently present some of the fallacies which have bring certain scepticism about the scientific character of the investigation in economy, to know: 1 The differences between hard and weak sciences -physics and social; 2 The differences between paradigm, —positivist and phenomenological— 3 The differences between physic causalityand historic causality. In the second step we are going to talk about two fundamental problems which are questioned: 1 the confusion between ontology and gnoseology and, 2 the erroneous concept of causality that commonly is used. In the last step of the paper we are going over the recent models of «causal explanation» and we suggest the probabilistic casualty development next with a more elaborated models of causal explanation, like a way to conjugate the scientific severity with the possibility to tackle complex economic realities.

  2. Avaliação da sensibilidade da cultura de leite do tanque para isolamento de agentes contagiosos da mastite bovina Evaluation of the sensitivity of bulk tank milk cultures for the isolation of contagious bovine mastitis pathogens

    Directory of Open Access Journals (Sweden)

    Maria Aparecida V. P. Brito

    1998-01-01

    Full Text Available Amostras de leite total (leite do tanque de 33 rebanhos foram coletadas na plataforma de recepção da indústria laticinista e cultivadas para detectar patógenos específicos (contagiosos da mastite. Foi feita a contagem de células somáticas (CCS das amostras utilizando o equipamento Fossomatic 90. Em 13 e 12 rebanhos avaliaram-se duas e três amostras semanais consecutivas, respectivamente, e em oito avaliou-se apenas uma. Foram também examinadas três amostras diárias consecutivas do leite do tanque e amostras dos quartos mamários individuais, coletadas na própria fazenda, de todas as vacas em lactação de quatro rebanhos (A, B, C e D. As amostras de leite dos quartos mamários individuais foram cultivadas em ágar sangue e as amostras do tanque, em placas de TKT, Sal Manitol, MacConkey e Sabouraud contendo cloranfenicol. Dos 33 rebanhos cujas amostras foram obtidas na plataforma de recepção da indústria, isolou-se Staphylococcus aureus de 26, nove desses em associação com Streptococcus agalactiae e em três rebanhos isolou-se somente S. agalactiae. Nove rebanhos tiveram CCS acima de 500.000 ml-1 e 21, abaixo de 400.000 ml-1. Em cinco dos nove rebanhos com CCS acima de 500.000 ml-1 foram isolados S. aureus e S. agalactiae, em três, apenas S. aureus e em um, apenas S. agalactiae. Seis rebanhos apresentaram CCS abaixo de 200.000 ml-1; de um deles foram isolados S. aureus e S. agalactiae, de três, S. aureus e os outros dois foram negativos para estes dois patógenos. Os resultados encontrados nos quatro rebanhos cujas amostras foram coletadas na própria fazenda mostraram que S. aureus foi isolado nas seguintes porcentagens dos animais: 1,8%, 19,2%, 17,0% e 8,4% e dos quartos mamários: 0,9%, 5,9%, 5,4% e 2,2%, respectivamente, para os rebanhos A, B, C e D. S. agalactiae foi isolado dos rebanhos A, C e D. Nestes três rebanhos, as porcentagens de isolamento foram, respectivamente, 1,8%, 10,6% e 8,4% para as vacas e 0,46%, 3,8% e 3

  3. Psicoterapia de grupo e considerações sobre o paciente como agente da própria mudança Psicoterapia de grupo y consideraciones sobre el paciente como agente del propio cambio Group psychotherapy and considerations concerning the patient as an agent for his own change

    OpenAIRE

    Luiz Paulo de C. Bechelli; Manoel Antônio dos Santos

    2002-01-01

    Nas últimas décadas a psicoterapia de grupo tem merecido considerável atenção por parte dos pesquisadores. Tendo por base publicações recentes, os autores tecem considerações sobre a indicação, a necessidade de se adotar critérios de seleção, os resultados esperados e o prognóstico, bem como o processo de mudança. A revisão da literatura evidencia tendência de se reconhecer o cliente como agente de sua própria mudança, e é colocada em relevo a forma particular que este processo assume na psic...

  4. Anticipation of physical causality guides eye movements

    OpenAIRE

    Wende, Kim; Theunissen, Laetitia; Missal, Marcus

    2016-01-01

    Causality is a unique feature of human perception. We present here a behavioral investigation of the influence of physical causality during visual pursuit of object collisions. Pursuit and saccadic eye movements of human subjects were recorded during ocular pursuit of two concurrently launched targets, one that moved according to the laws of Newtonian mechanics (the causal target) and the other one that moved in a physically implausible direction (the non-causal target). We found that anticip...

  5. Causal discovery from medical textual data.

    OpenAIRE

    Mani, S.; Cooper, G. F.

    2000-01-01

    Medical records usually incorporate investigative reports, historical notes, patient encounters or discharge summaries as textual data. This study focused on learning causal relationships from intensive care unit (ICU) discharge summaries of 1611 patients. Identification of the causal factors of clinical conditions and outcomes can help us formulate better management, prevention and control strategies for the improvement of health care. For causal discovery we applied the Local Causal Discove...

  6. Estimating causal structure using conditional DAG models

    OpenAIRE

    Oates, Chris J.; Smith, Jim Q.; Mukherjee, Sach

    2014-01-01

    This paper considers inference of causal structure in a class of graphical models called "conditional DAGs". These are directed acyclic graph (DAG) models with two kinds of variables, primary and secondary. The secondary variables are used to aid in estimation of causal relationships between the primary variables. We give causal semantics for this model class and prove that, under certain assumptions, the direction of causal influence is identifiable from the joint observational distribution ...

  7. Controle biológico da murcha bacteriana do tomateiro, por Pseudomonas spp. fluorescentes Biological control of bacterial wilt of tomato by fluorescent Pseudomonas spp

    OpenAIRE

    Ana Rosa Peixoto

    1997-01-01

    Esta revisão bibliográfica teve como objetivo avaliar o potencial de antagonismo de espécies de Pseudomonas fluorescentes a Pseudomonas solanacearum, agente causal da murcha bacteriana do tomateiro. Devido a dificuldade encontrada nas estratégias utilizadas para o controle da Murcha Bacteriana por meio de métodos convencionais, alguns outros tem sido estudados, como o uso de microrganismos benéficos. As rizobactérias vem proporcionando solução viável a algumas doenças consideradas de difícil ...

  8. Representing Personal Determinants in Causal Structures.

    Science.gov (United States)

    Bandura, Albert

    1984-01-01

    Responds to Staddon's critique of the author's earlier article and addresses issues raised by Staddon's (1984) alternative models of causality. The author argues that it is not the formalizability of causal processes that is the issue but whether cognitive determinants of behavior are reducible to past stimulus inputs in causal structures.…

  9. The argumentative impact of causal relations

    DEFF Research Database (Denmark)

    Nielsen, Anne Ellerup

    1996-01-01

    causality, explanation and justification. In certain types of discourse, causal relations also imply an intentional element. This paper describes the way in which the semantic and pragmatic functions of causal markers can be accounted for in terms of linguistic and rhetorical theories of argumentation....

  10. Expectations and Interpretations during Causal Learning

    Science.gov (United States)

    Luhmann, Christian C.; Ahn, Woo-kyoung

    2011-01-01

    In existing models of causal induction, 4 types of covariation information (i.e., presence/absence of an event followed by presence/absence of another event) always exert identical influences on causal strength judgments (e.g., joint presence of events always suggests a generative causal relationship). In contrast, we suggest that, due to…

  11. Representações do envelhecimento em agentes comunitários da saúde e profissionais da enfermagem comunitária: aspectos psicológicos do processo saúde-doença Representations of aging for community health agents and nursing professionals: psychological aspects of the health-disease process

    Directory of Open Access Journals (Sweden)

    Rochele Paz Fonseca

    2008-08-01

    Full Text Available No âmbito do tema saúde pública e envelhecimento, o objetivo desse estudo foi averiguar quais são as representações do processo de envelhecimento para profissionais da saúde pública e como essas se expressam na atenção à saúde, no bem-estar e no cuidado do idoso. Participaram 27 profissionais (dez agentes comunitários de saúde e dezessete profissionais de enfermagem. Utilizaram-se dois instrumentos, um questionário sociocultural e um questionário sobre as representações do envelhecimento. Os dados foram analisados qualitativa e quantitativamente (teste qui-quadrado. As palavras mais representativas para expressar o envelhecimento foram aposentadoria e descanso. O fator que mais influenciou o bem-estar e o cuidado do indivíduo idoso foi uma boa rede familiar. Quanto à definição de cuidado, os aspectos biológicos foram os mais freqüentes. A amostra apresentou noções sobre a doença de Alzheimer. Assim sendo, os dados encontrados trazem implicações para a capacitação de recursos humanos. Os agentes de saúde e os profissionais de enfermagem devem ser auxiliados no processo de construção de uma melhor compreensão do contexto biopsicossocial em que o envelhecimento está inserido.This paper addresses the aging process in the context of public health, with emphasis to human resources and to how aging is perceived by the public health professionals. The aim of this study was to identify the representations of the aging process for public health professionals and how these representations are expressed in health care, well-being and elderly care. The sample included 27 public health professionals, 10 community health agents and 17 nursing professionals. Two instruments were used, a sociocultural questionnaire and a questionnaire about aging representations. Data analysis included qualitative and quantitative procedures (Chi-square test. Among the main findings, the most representative words used in relation to aging were

  12. Do debit cards decrease cash demand? Evidence from a causal analysis using Principal Stratification

    OpenAIRE

    Mercatanti, Andrea; Li, Fan

    2015-01-01

    It has been argued that innovation in transaction technology may modify the cash holding behaviour of agents, as debit card holders may either withdraw cash from ATMs or purchase items using POS devices at retailers. In this paper, within the Rubin Causal Model, we investigate the causal effects of the use of debit cards on the cash inventories held by households using data from the Italy Survey of Household Income and Wealth (SHIW). We adopt the principal stratification approach to incorpora...

  13. Strawberry sterility - what is the causal agents(s)

    Czech Academy of Sciences Publication Activity Database

    Fránová, Jana

    Ankara : Mustafa Kemal University, 2006, s. 68. [XXth International Symposium on Virus and Virus-like Diseases of Temperate Fruit Crops and XIth International Symposium of Small Fruit Virus Diseases. Antalya (TR), 22.05.2006-26.05.2006] R&D Projects: GA AV ČR(CZ) 1QS500510558 Institutional research plan: CEZ:AV0Z50510513 Keywords : Strawberry sterility Subject RIV: EE - Microbiology, Virology

  14. Strawberry sterility - what is the causal agents(s)

    Czech Academy of Sciences Publication Activity Database

    Fránová, Jana; Paprštein, F.; Kučerová, J.

    Ankara : Mustafa Kemal University, 2006, s. 57. [XXth International Symposium on Virus and Virus-like Diseases of Temperate Fruit Crops and XIth International Symposium of Small Fruit Virus Diseases. Antalya (TR), 22.05.2006-26.05.2006] R&D Projects: GA AV ČR(CZ) 1QS500510558 Institutional research plan: CEZ:AV0Z50510513 Keywords : Molecular identification * apple trees * pear trees * Czech Republic Subject RIV: EE - Microbiology, Virology

  15. Avaliação do método de disco-difusão para determinação da eficácia da terbinafina in vitro em agentes de micoses superficiais e subcutâneas Evaluation of the disk-diffusion method to determine the in vitro efficacy of terbinafine against subcutaneous and superficial mycoses agents

    Directory of Open Access Journals (Sweden)

    Hilda Conceição Diogo

    2010-06-01

    Full Text Available FUNDAMENTOS: As micoses superficiais e subcutâneas têm alta prevalência e, muitas vezes, caráter crônico, necessitando tratamentos tópicos e/ou sistêmicos com antifúngicos. As drogas de escolha são azóis e alilaminas (terbinafina. É necessário avaliar a eficácia das drogas para tratamento em humanos e em animais. Estudos para avaliar in vitro a ação dos antimicóticos são raros, especialmente, contra fungos filamentosos. OBJETIVO: Avaliar a eficácia in vitro da terbinafina pelo método de disco-difusão contra fungos filamentosos e leveduras agentes de micoses. MÉTODOS: Avaliou-se a ação da terbinafina (0,125µg-100µg contra dez espécies fúngicas pelos métodos discodifusão e microdiluição/referência, para determinar a concentração inibitória mínima (MIC. RESULTADOS: Observou-se alta sensibilidade à terbinafina em: T. rubrum, M. gypseum, T. mentagrophytes, T. tonsurans, M. canis, C. carrionii e E. floccosum (halo ≥ 40mm com disco de 0,125µg. S. hyalinum e C. parapsilosis foram considerados sensíveis, mas com halos menores. Fusarium spp. apresentou menor sensibilidade (halo=12mm com disco de 2µg; MIC 8µg/mL. CONCLUSÕES: Os resultados reiteram estudos anteriores quanto à alta eficácia da terbinafina em relação a dermatófitos. A técnica de disco-difusão foi de fácil aplicação e adequada na rotina de laboratórios clínicos.BACKGROUND: Superficial and subcutaneous mycoses have a high prevalence and, often, chronic evolution. Therefore, they need extensive treatment with topic and/or systemic antifungal agents. Azoles and alilamines (terbinafine are first-choice drugs to treat human and animal infections. Thus, evaluation of the efficacy of these drugs is important for a successful treatment. However, there are few studies that evaluate the in vitro activity of antifungal agents. OBJECTIVE: To evaluate the in vitro efficacy of terbinafine activity against filamentous fungi and yeasts that cause mycoses

  16. Principal Stratification in Causal Inference

    OpenAIRE

    Frangakis, Constantine E.; Rubin, Donald B.

    2002-01-01

    Many scientific problems require that treatment comparisons be adjusted for posttreatment variables, but the estimands underlying standard methods are not causal effects. To address this deficiency, we propose a general framework for comparing treatments adjusting for posttreatment variables that yields principal effects based on principal stratification. Principal stratification with respect to a posttreatment variable is a cross-classification of subjects defined by the joint potential valu...

  17. Influência do tipo de agente de partição da borracha nitrílica na obtenção de blendas PVC/NBR Influence of the partitioning agent on the preparation of PVC/NBR Blends

    Directory of Open Access Journals (Sweden)

    Fábio R. Passador

    2008-09-01

    Full Text Available Borrachas nitrílicas para utilização em misturas com PVC são fornecidas em forma de pó, que são recobertas com um agente de partição para evitar compactação do produto no transporte e armazenamento, além de garantir alta fluidez e livre escoamento. Neste trabalho, buscou-se estudar a influência do tipo de agente de partição da borracha nitrílica (resina de PVC e CaCO3 na obtenção de blendas PVC/NBR. As propriedades mecânicas das blendas foram avaliadas por ensaios de tração, rasgo e dureza. As blendas com NBR com agente de partição de PVC apresentaram maior tensão na ruptura e módulo elástico que as blendas em que utilizaram NBR com agente de partição de CaCO3. A morfologia foi avaliada por microscopia eletrônica de varredura sendo bastante afetada pelo tipo de agente de partição.Nitrile rubbers used in mixture with PVC resin are supplied in powder. This kind of nitrile rubber has a partitioning agent to avoid agglomeration in the particles during the transport and storage. In this study, the influence of the partitioning agent on the preparation of PVC/NBR blends was investigated. The mechanical properties of the blends were evaluated by tensile properties, tear strength and hardness. The PVC/NBR blends with partitioning agent of PVC showed an increase in the tensile stress and Young's modulus compared to the PVC/NBR blends with partitioning agent of CaCO3. The morphology of the blends examined by scanning electron microscopy demonstrated the influence of the partitioning agent.

  18. Partial chemical characterization of antigenic preparations of chromoblastomycosis agents Caracterização química parcial de preparações antigênicas de agentes da cromoblastomicose

    Directory of Open Access Journals (Sweden)

    Tania Fraga BARROS

    1999-11-01

    Full Text Available Antigenic preparations (saline, methylic, metabolic and exoantigens of four agents of chromoblastomycosis, Fonsecaea pedrosoi, Phialophora verrucosa, Cladophialophora (Cladosporium carrionii and Rhinocladiella aquaspersa were obtained. Partial chemical characterization of these antigenic preparations was obtained by determination of the levels of total lipids, protein, and carbohydrates, and identification of the main sterols and carbohydrates. Methylic antigens presented the highest lipid contents, whereas metabolic antigens showed the highest carbohydrate content. Total lipid, protein, and carbohydrate levels were in the range of 2.33 to 2.00mg/ml, 0.04 to 0.02 mg/ml and 0.10 to 0.02 mg/ml, respectively, in the methylic antigens and in the range of 0.53 to 0.18mg/ml, 0.44 to 0.26mg/ml, and 1.82 to 1.02 mg/ml, respectively, in saline antigens. Total lipid, protein, and carbohydrate contents were in the range of 0.55 to 0.20mg/ml, 0.69 to 0.57mg/ml and 10.73 to 5.93mg/ml, respectively, in the metabolic antigens, and in the range of 0.55 to 0.15mg/ml, 0.62 to 0.20mg/ml and 3.55 to 0.42mg/ml, respectively, in the exoantigens. Phospholipids were not detected in the preparations. Saline and metabolic antigens and exoantigens presented hexose and the methylic antigen revealed additional pentose units in their composition. The UV light absorption spectra of the sterols revealed squalene and an ergosterol fraction in the antigens. The characterization of these antigenic preparations may be useful for serological evaluation of patients of chromoblastomycosis.Preparações antigênicas (antígenos salinos, metílicos, metabólicos e exoantígenos de quatro agentes da cromoblastomicose, Fonsecaea pedrosoi, Phialophora verrucosa, Cladophialophora (Cladosporium carrionii e Rhinocladiella aquaspersa foram obtidos e foi determinada a caracterização química parcial dos mesmos. Os antígenos metílicos apresentaram os maiores teores de lípides enquanto os

  19. Entanglement, Holography and Causal Diamonds

    CERN Document Server

    de Boer, Jan; Heller, Michal P; Myers, Robert C

    2016-01-01

    We argue that the degrees of freedom in a d-dimensional CFT can be re-organized in an insightful way by studying observables on the moduli space of causal diamonds (or equivalently, the space of pairs of timelike separated points). This 2d-dimensional space naturally captures some of the fundamental nonlocality and causal structure inherent in the entanglement of CFT states. For any primary CFT operator, we construct an observable on this space, which is defined by smearing the associated one-point function over causal diamonds. Known examples of such quantities are the entanglement entropy of vacuum excitations and its higher spin generalizations. We show that in holographic CFTs, these observables are given by suitably defined integrals of dual bulk fields over the corresponding Ryu-Takayanagi minimal surfaces. Furthermore, we explain connections to the operator product expansion and the first law of entanglement entropy from this unifying point of view. We demonstrate that for small perturbations of the va...

  20. Psicoterapia de grupo e considerações sobre o paciente como agente da própria mudança Psicoterapia de grupo y consideraciones sobre el paciente como agente del propio cambio Group psychotherapy and considerations concerning the patient as an agent for his own change

    Directory of Open Access Journals (Sweden)

    Luiz Paulo de C. Bechelli

    2002-06-01

    Full Text Available Nas últimas décadas a psicoterapia de grupo tem merecido considerável atenção por parte dos pesquisadores. Tendo por base publicações recentes, os autores tecem considerações sobre a indicação, a necessidade de se adotar critérios de seleção, os resultados esperados e o prognóstico, bem como o processo de mudança. A revisão da literatura evidencia tendência de se reconhecer o cliente como agente de sua própria mudança, e é colocada em relevo a forma particular que este processo assume na psicoterapia de grupo.En las últimas décadas, la psicoterapia de grupo ha merecido considerable atención por parte de los investigadores. Teniendo como base publicaciones recientes, los autores hacen consideraciones sobre la indicación, la necesidad de adoptar criterios de selección, los resultados esperados y el pronóstico, así como también el proceso de cambio. La revisión de la literatura evidencia la tendencia de reconocer el cliente como agente de su proprio cambio, siendo enfatizada la forma particular que este proceso asume en la psicoterapia de grupo.In the last few decades, group psychotherapy has deserved considerable attention from researchers. Based on recent publications, the authors of this work make considerations concerning the indication, the need to adopt a selection criteria, expected results and prognoses as well as the change process. Literature review shows a tendency to recognize the client as an agent for his own change. The particular shape which is taken by this process in group psychotherapy is pointed out.

  1. Influência dos agentes clareadores e um refrigerante a base de cola na microdureza do esmalte dental e a ação da saliva na superfície tratada = Influence of bleaching agents and a carbonated soft drink on dental enamel microhardness as well as the artificial saliva effect on the treated surface

    Directory of Open Access Journals (Sweden)

    Araújo, Rodrigo Maximo de

    2006-01-01

    Full Text Available O objetivo deste estudo foi avaliar os efeitos de três agentes clareadores e uma bebida carbonatada, à base de cola, sobre a microdureza do esmalte dental, assim como os efeitos da saliva artificial sobre o esmalte tratado com estes agentes. Foram utilizados quarenta dentes incisivos bovinos embutidos em resina acrílica. As amostras foram avaliadas em microdurômetro (Future Tech FM 700 após a divisão em quatro grupos, uma leitura inicial da microdureza serviu como controle do experimento: Grupo 1: peróxido de carbamida a 10% (Whiteness Perfect – FGM; Grupo 2: refrigerante Coca-Cola; Grupo 3: peróxido de carbamida a 37% (Whiteness Super – FGM; Grupo 4: peróxido de hidrogênio a 35% (Whiteness HP – FGM. Os dados foram submetidos aos testes estatísticos ANOVA e Tukey. Conclui-se que os agentes clareadores não diminuíram a microdureza do esmalte; a exposição à Coca-Cola diminuiu significantemente a microdureza do esmalte; o tempo de exposição aos agentes foi significante apenas para a Coca- Cola; o armazenamento em saliva aumentou a microdureza do esmalte exposto ao peróxido de carbamida a 37%; à Coca-Cola e ao peróxido de hidrogênio à 35%

  2. Identificação de agentes infecciosos pulmonares em autópsias de pacientes com a síndrome da imunodeficiência adquirida Identification of infectious agents in the lungs in autopsies of patients with acquired immunodeficiency syndrome

    Directory of Open Access Journals (Sweden)

    Sanivia Aparecida de Lima Pereira

    2002-12-01

    Full Text Available As afecções pulmonares são freqüentes em indivíduos infectados pelo vírus da imunodeficiência humana. Neste trabalho, procurou-se identificar através de histoquímica e imunohistoquímica, agentes infecciosos nos pulmões de indivíduos portadores da síndrome da imunodeficiência adquirida (SIDA, autopsiados entre março de 1990 e julho de 2000 na FMTM. Fragmentos de pulmão de 40 indivíduos com SIDA autopsiados foram analisados histologicamente. Foram identificados agentes infecciosos em 34 (85% casos dos 40 analisados, sendo que bactérias foram encontradas em 22 (55% casos. Entre os agentes fúngicos o Pneumocystis carinii foi encontrado em oito (19,1% casos; Cryptococcus sp em quatro (9,5%, Histoplasma sp em dois (4,8% e Candida sp em um (2,4% caso. Detectou-se também associação entre Pneumocystis carinii, Citomegalovirus e Cryptococcus sp; CMV e Toxoplasma gondii. Em cinco casos, Candida sp, CMV e Pneumocystis carinii estiveram associados a bactérias. Entre as infecções não bacterianas, os fungos foram os agentes infecciosos mais isolados dos pulmões em autópsias de indivíduos com SIDA, sendo o Pneumocystis carinii o mais freqüente.Lung diseases are frequently observed in individuals infected with HIV. The aim of this study was to identify infectious agents in the lungs in the autopsied individuals with AIDS performed between march 1990 and july 2000 at the school of medicine (Uberaba- Brazil, using histochemical and immunohistochemical techniques. Analysis was made on lungs obtained from 40 individuals with AIDS. Infectious agents were observed in 34 (85% cases of the 40 analyzed. Regarding fungis, Pneumocystis carinii was found in 8 (19.1%cases; Cryptococcus sp in 4 (9.5%cases, Histoplasma sp in 2 (4.8%cases and Candida sp in 1 (2.4%case. Association of Pneumocystis carinii, Citomegalovirus and Cryptococcus sp, was observed in one case, and in another, the association of CMV, and Toxoplasma gondii. There were 5 cases

  3. Finitary Spacetime Sheaves of Quantum Causal Sets Curving Quantum Causality

    CERN Document Server

    Mallios, A

    2001-01-01

    A locally finite, causal and quantal substitute for a locally Minkowskian principal fiber bundle $\\cal{P}$ of modules of Cartan differential forms $\\omg$ over a bounded region $X$ of a curved $C^{\\infty}$-smooth differential manifold spacetime $M$ with structure group ${\\bf G}$ that of orthochronous Lorentz transformations $L^{+}:=SO(1,3)^{\\uparrow}$, is presented. ${\\cal{P}}$ is the structure on which classical Lorentzian gravity, regarded as a Yang-Mills type of gauge theory of a $sl(2,\\com)$-valued connection 1-form $\\cal{A}$, is usually formulated. The mathematical structure employed to model this replacement of ${\\cal{P}}$ is a principal finitary spacetime sheaf $\\vec{\\cal{P}}_{n}$ of quantum causal sets $\\amg_{n}$ with structure group ${\\bf G}_{n}$, which is a finitary version of the group ${\\bf G}$ of local symmetries of General Relativity, and a finitary Lie algebra ${\\bf g}_{n}$-valued connection 1-form ${\\cal{A}}_{n}$ on it, which is a section of its sub-sheaf $\\amg^{1}_{n}$. ${\\cal{A}}_{n}$ is phys...

  4. Opinião dos agentes comunitários de saúde sobre o uso da videoconferência na capacitação em saúde auditiva infantil Community health agents' opinions on the use of videoconference in children health hearing training

    Directory of Open Access Journals (Sweden)

    Tatiana Mendes de Melo

    2011-08-01

    Full Text Available OBJETIVO: avaliar a videoconferência como ferramenta instrucional na capacitação dos agentes comunitários de saúde, em saúde auditiva infantil, sob a perspectiva destes profissionais. METODOLOGIA: a casuística foi composta por 50 agentes comunitários de saúde, divididos aleatoriamente em dois grupos de acordo com a metodologia de ensino: 31 profissionais participaram da capacitação de forma presencial e 19 por meio de videoconferência. A atividade ocorreu em um encontro de oito horas, por meio de aulas expositivas e utilizando material didático adaptado e validado para o português proposto pela Organização Mundial da Saúde de forma simultânea para ambos os grupos. A avaliação da videoconferência como ferramenta instrucional foi realizada por meio de questionário elaborado para o presente estudo. RESULTADOS: a avaliação da videoconferência foi muito semelhante em ambos os grupos, sendo que a ferramenta de ensino foi considerada como de fácil entendimento e permitindo a interação com o ministrante. CONCLUSÃO: a videoconferência foi uma ferramenta válida e aceita pelos profissionais estudados para ser utilizada em programas de capacitação em saúde auditiva infantil.PURPOSE: to check the opinion from community health agents about the use of videoconference as instructional tool in children hearing health program training. METHODS: the group was made up by 50 community health agents divided randomly in two groups, with the following sample: 31 community health agents by face-to-face instruction and 19, by videoconference. The training was provided in eight hours, through classes and a textbook translated and adapted into the Brazilian Portuguese language proposed by World Health Organization, in both groups, simultaneously. In order to investigate the opinion about the use of videoconference as instructional tool in training program, a questionnaire was done and applied, in both group, after the course. RESULTS: the

  5. The Impossibility of Causality Testing

    OpenAIRE

    Conway, Roger K.; P. A. V. B. Swamy; Yanagida, John F.; Muehlen, Peter von zur

    1984-01-01

    Causality tests developed by Sims and Granger are fatally flawed for several reasons First, when two variables, X and Y, are uncorrelated, X has no linear predictive value for Y, but X,and Y may be nonlinearly related unless they are statistically Independent, In which case X and Y are not related at all The light-hand side variables In a regression equation are exogenous If they are mean Independent of the disturbance term Mean Independence IS stronger than uncorrelatedness The proofs for de...

  6. Breaking the arrows of causality

    DEFF Research Database (Denmark)

    Valsiner, Jaan

    2014-01-01

    Theoretical models of catalysis have proven to bring with them major breakthroughs in chemistry and biology, from the 1830s onward. It can be argued that the scientific status of chemistry has become established through the move from causal to catalytic models. Likewise, the central explanatory...... role of cyclical models in biology has made it possible to move from the idea of genetic determination to that of epigenetic negotiation as the core of biological theory. In psychology, catalytic thinking has been outside of the realm of accepted scientific schemes, as the axiomatic dependence upon the...

  7. The Functions of Danish Causal Conjunctions

    Directory of Open Access Journals (Sweden)

    Rita Therkelsen

    2004-01-01

    Full Text Available In the article I propose an analysis of the Danish causal conjunctions fordi, siden and for based on the framework of Danish Functional Grammar. As conjunctions they relate two clauses, and their semantics have in common that it indicates a causal relationship between the clauses. The causal conjunctions are different as far as their distribution is concerned; siden conjoins a subordinate clause and a main clause, for conjoins two main clauses, and fordi is able to do both. Methodologically I have based my analysis on these distributional properties comparing siden and fordi conjoining a subordinate and a main clause, and comparing for and fordi conjoining two main clauses, following the thesis that they would establish a causal relationship between different kinds of content. My main findings are that fordi establishes a causal relationship between the events referred to by the two clauses, and the whole utterance functions as a statement of this causal relationship. Siden presupposes such a general causal relationship between the two events and puts forward the causing event as a reason for assuming or wishing or ordering the caused event, siden thus establishes a causal relationship between an event and a speech act. For equally presupposes a general causal relationship between two events and it establishes a causal relationship between speech acts, and fordi conjoining two main clauses is able to do this too, but in this position it also maintains its event-relating ability, the interpretation depending on contextual factors.

  8. Space and time in perceptual causality

    Directory of Open Access Journals (Sweden)

    Benjamin Straube

    2010-04-01

    Full Text Available Inferring causality is a fundamental feature of human cognition that allows us to theorize about and predict future states of the world. Michotte suggested that humans automatically perceive causality based on certain perceptual features of events. However, individual differences in judgments of perceptual causality cast doubt on Michotte’s view. To gain insights in the neural basis of individual difference in the perception of causality, our participants judged causal relationships in animations of a blue ball colliding with a red ball (a launching event while fMRI-data were acquired. Spatial continuity and temporal contiguity were varied parametrically in these stimuli. We did not find consistent brain activation differences between trials judged as caused and those judged as non-caused, making it unlikely that humans have universal instantiation of perceptual causality in the brain. However, participants were slower to respond to and showed greater neural activity for violations of causality, suggesting that humans are biased to expect causal relationships when moving objects appear to interact. Our participants demonstrated considerable individual differences in their sensitivity to spatial and temporal characteristics in perceiving causality. These qualitative differences in sensitivity to time or space in perceiving causality were instantiated in individual differences in activation of the left basal ganglia or right parietal lobe, respectively. Thus, the perception that the movement of one object causes the movement of another is triggered by elemental spatial and temporal sensitivities, which themselves are instantiated in specific distinct neural networks.

  9. Distribuição Espacial e Rotas de Disseminação dos Agentes e da Infecção da Leishmaniose Visceral Americana em Humanos e Animais do Estado de São Paulo | Spatial Distribution and Means of Dissemination of the Agents and Infection of American Visceral Leish

    Directory of Open Access Journals (Sweden)

    Lourdes Aparecida Zampieri D'Andrea

    2014-05-01

    Full Text Available Normal 0 21 false false false PT-BR X-NONE X-NONE Introdução: A Leishmaniose Visceral Americana (LVA caracteriza-se hoje como a principal endemia parasitária do Estado de São Paulo e de diversas outras regiões brasileiras. Hoje a autoctonia da LVA com casos humanos e/ou caninos está identificada nas regiões abrangidas pelos Departamentos Regionais de Saúde de Araçatuba, Bauru, Marília, Presidente Prudente, São José do Rio Preto, Campinas, Sorocaba e Região Metropolitana da Grande São Paulo. Muito pouco se conhece sobre a diversidade das leishmânias circulantes em São Paulo. Considerando-se o arsenal de técnicas e metodologias hoje disponíveis para a identificação específica e mesmo de subpopulações dos protozoários do gênero Leishmania, seja para o esclarecimento de áreas silenciosas, ou de importância epidemiológica; melhoria do diagnóstico laboratorial; na prospecção de fatores ambientais associados a transmissão, torna-se imprescindível conhecer a distribuição espacial e as rotas de disseminação de leishmanias circulantes no estado e suas interações escalares, com base na infecção em humanos e animais. Ao enfrentar estes desafios, o trabalho nos remete a uma questão maior: em que medida a categoria espaço é fundamental para se compreender o processo saúde-doença? O presente projeto tem como proposta o desenvolvimento de uma visão integrada das condições socio-ambientais do ciclo de transmissão da Leishmaniose Viceral Americana (LVA no estado de São Paulo. Metodologia/Desenvolvimento: Para isto fará uso de conhecimentos geoepidemiológicos e de ferramentas de geoprocessamento e análise espacial para analisar as rotas de disseminação dos agentes e da infecção da doença na população canina e humana. Para entender o contexto da área, será realizado o levantamento ambiental, que constitui a criação de bases cartográficas que tenham sido elencadas como explicativas do fen

  10. Probabilistic causality and radiogenic cancers

    International Nuclear Information System (INIS)

    A review and scrutiny of the literature on probability and probabilistic causality shows that it is possible under certain assumptions to estimate the probability that a certain type of cancer diagnosed in an individual exposed to radiation prior to diagnosis was caused by this exposure. Diagnosis of this causal relationship like diagnosis of any disease - malignant or not - requires always some subjective judgments by the diagnostician. It is, therefore, illusory to believe that tables based on actuarial data can provide objective estimates of the chance that a cancer diagnosed in an individual is radiogenic. It is argued that such tables can only provide a base from which the diagnostician(s) deviate in one direction or the other according to his (their) individual (consensual) judgment. Acceptance of a physician's diagnostic judgment by patients is commonplace. Similar widespread acceptance of expert judgment by claimants in radiation compensation cases does presently not exist. Judicious use of the present radioepidemiological tables prepared by the Working Group of the National Institutes of Health or of updated future versions of similar tables may improve the situation. 20 references

  11. Shear bond strength after dentin bleaching with 10% carbamide peroxide agents Resistência ao cisalhamento da dentina após clareamento com peróxido de carbamida a 10%

    Directory of Open Access Journals (Sweden)

    Roberta Tarkany Basting

    2004-06-01

    Full Text Available This in vitro study evaluated the shear bond strength (SBS of dentin treated with two 10% carbamide peroxide bleaching agents 15 days after bleaching and storage in artificial saliva. Dentin fragments were randomly divided into 3 groups (n = 20 for the treatment with the two different bleaching agents (Rembrandt 10% or Opalescence 10% or with a placebo agent, applied to the tooth surface for 8 hours a day. During the remaining time, the specimens were stored in artificial saliva. After 42 days, the fragments were stored in artificial saliva for 14 days. Another group (n = 20 was exposed to distilled and deionized water for 56 days. An adhesive system and microhybrid composite resin were used to prepare specimens for the SBS test. SBS tests were performed and the fractured surfaces were visually examined using a stereoscope at 30 X magnification. The analysis of variance (ANOVA and SIDAK tests showed higher SBS values for dentin treated with Opalescence 10% than for dentin treated with Rembrandt 10% or placebo. Groups treated with Rembrandt 10%, Opalescence 10% or placebo did not differ from the group treated with distilled and deionized water. Ten percent carbamide peroxide agents or a placebo agent caused no differences in SBS of dentin after 15 days of storage in artificial saliva.Este estudo in vitro avaliou a resistência ao cisalhamento da dentina submetida ao tratamento com dois agentes clareadores contendo peróxido de carbamida a 10% depois de 15 dias de clareamento e armazenagem em saliva artificial. Fragmentos de dentina foram aleatoriamente distribuídos em 3 grupos (n = 20 para receber o tratamento com dois diferentes agentes clareadores (Rembrandt a 10% ou Opalescence a 10% ou com um agente placebo, aplicados na superfície dental por 8 horas diárias. No restante do tempo, os espécimens permaneceram imersos em saliva artificial. Após o tratamento por 42 dias, os fragmentos foram armazenados em saliva artificial por 14 dias. Outro

  12. Causal relationship: a new tool for the causal characterization of Lorentzian manifolds

    International Nuclear Information System (INIS)

    We define and study a new kind of relation between two diffeomorphic Lorentzian manifolds called a causal relation, which is any diffeomorphism characterized by mapping every causal vector of the first manifold onto a causal vector of the second. We perform a thorough study of the mathematical properties of causal relations and prove in particular that two given Lorentzian manifolds (say V and W) may be causally related only in one direction (say from V to W, but not from W to V). This leads us to the concept of causally equivalent (or isocausal in short) Lorentzian manifolds as those mutually causally related and to a definition of causal structure over a differentiable manifold as the equivalence class formed by isocausal Lorentzian metrics upon it. Isocausality is a more general concept than the conformal relationship, because we prove the remarkable result that a conformal relation φ is characterized by the fact of being a causal relation of the particular kind in which both φ and φ-1 are causal relations. Isocausal Lorentzian manifolds are mutually causally compatible, they share some important causal properties, and there are one-to-one correspondences, which are sometimes non-trivial, between several classes of their respective future (and past) objects. A more important feature is that they satisfy the same standard causality constraints. We also introduce a partial order for the equivalence classes of isocausal Lorentzian manifolds providing a classification of all the causal structures that a given fixed manifold can have. By introducing the concept of causal extension we put forward a new definition of causal boundary for Lorentzian manifolds based on the concept of isocausality, and thereby we generalize the traditional Penrose constructions of conformal infinity, diagrams and embeddings. In particular, the concept of causal diagram is given. Many explicit clarifying examples are presented throughout the paper

  13. FDI and growth: a causal relationship

    OpenAIRE

    Chowdhury, Abdur; Mavrotas, George

    2005-01-01

    The paper examines the causal relationship between FDI and economic growth by using an innovative econometric methodology to study the direction of causality between the two variables. We apply our methodology, based on the Toda-Yamamoto test for causality, to time-series data covering the period 1969-2000 for three developing countries, namely Chile, Malaysia and Thailand, all of them major recipients of FDI with a different history of macroeconomic episodes, policy regimes and growth patter...

  14. Linear causal modeling with structural equations

    CERN Document Server

    Mulaik, Stanley A

    2009-01-01

    Emphasizing causation as a functional relationship between variables that describe objects, Linear Causal Modeling with Structural Equations integrates a general philosophical theory of causation with structural equation modeling (SEM) that concerns the special case of linear causal relations. In addition to describing how the functional relation concept may be generalized to treat probabilistic causation, the book reviews historical treatments of causation and explores recent developments in experimental psychology on studies of the perception of causation. It looks at how to perceive causal

  15. The problem of causality in cultivation research

    OpenAIRE

    Rossmann, Constanze; Brosius, Hans-Bernd

    2004-01-01

    This paper offers an up-to-date review of problems in determining causal relationships in cultivation research, and considers the research rationales of various approaches with special reference to causal interpretation. It describes in turn a number of methodologies for addressing the problem and resolving it as far as this is possible. The issue of causal inference arises not only in cultivation research, however, but is basic to all media effects theories and approaches primarily at the ma...

  16. Causal inference in economics and marketing.

    Science.gov (United States)

    Varian, Hal R

    2016-07-01

    This is an elementary introduction to causal inference in economics written for readers familiar with machine learning methods. The critical step in any causal analysis is estimating the counterfactual-a prediction of what would have happened in the absence of the treatment. The powerful techniques used in machine learning may be useful for developing better estimates of the counterfactual, potentially improving causal inference. PMID:27382144

  17. Causal inference in economics and marketing

    Science.gov (United States)

    Varian, Hal R.

    2016-01-01

    This is an elementary introduction to causal inference in economics written for readers familiar with machine learning methods. The critical step in any causal analysis is estimating the counterfactual—a prediction of what would have happened in the absence of the treatment. The powerful techniques used in machine learning may be useful for developing better estimates of the counterfactual, potentially improving causal inference. PMID:27382144

  18. Extrato etanólico de representantes de cinco famílias de plantas e óleo essencial da família Asteraceae sobre o fungo Colletotrichum gloeosporioides coletados de frutos de mamoeiro (Carica papaya L.).

    OpenAIRE

    Bonett, Lucimar Pereira; Muller, Giovana Mayara; Wessling, Cláudia Regina; Gamelo, Fernanda Pompermeyer

    2012-01-01

    Colletotrichum gloeosporioides é o agente causal da antracnose, principal doença pós-colheita do mamoeiro. O objetivo deste trabalho foi verificar a fungitoxicidade do extrato etanólico de representantes de cinco famílias de plantas e óleo essencial da família Asteraceae sobre o fungo Colletotrichum gloeosporioides coletados de frutos de mamoeiro (Carica papaya L.). Na produção dos extratos etanólico foi utilizado onze plantas, sendo duas para a obtenção do óleo essencial. Os extratos foram o...

  19. The role of prescriptive norms and knowledge in children's and adults' causal selection.

    Science.gov (United States)

    Samland, Jana; Josephs, Marina; Waldmann, Michael R; Rakoczy, Hannes

    2016-02-01

    A widely discussed discovery has been the influence of norms on causal selection. Confronted with scenarios in which 2 agents contribute equally to an effect, adult participants tend to choose the agent who is violating a norm over an agent who is conforming to a norm as the cause of the outcome. To date, this effect has been established only in adult populations, so its developmental course is unknown. In 2 experiments, we investigated the influence of norm violations on causal selection in both 5-year-old children and adults. In particular, we focused on the role of mental state ascription and blame evaluation as potential mediating factors in this process. To this end, the knowledge status of the agent in question was varied such that she either was or was not aware of her norm transgression. Results revealed that children and adults assigned blame differently: Only adults were sensitive to the knowledge of the agent about norms as a mitigating factor. Crucially, however, despite its different sensitivity to knowledge ascription in children and adults, blame assignment in both age groups affected causal selection in the same ways. The relevance of these findings for alternative theories of causal selection is discussed. PMID:26726914

  20. Formação técnica do agente comunitário de saúde: desafios e conquistas da Escola Técnica de Saúde do Tocantins Technical training of community health agents: challenges and achievements of the Technical School of Health of Tocantins

    Directory of Open Access Journals (Sweden)

    Clemilson Antonio da Silva

    2009-11-01

    Full Text Available Este relato versa sobre a experiência da Escola Técnica de Saúde do Tocantins no processo educativo de formação técnica dos agentes comunitários de saúde. Trata-se aqui de apresentar como esses agentes foram capacitados para atuar junto à equipe multiprofissional de saúde em uma perspectiva profissional transformadora da realidade, crítica, reflexiva e ética, destacando-se o desenvolvimento das ações de integração social, promoção da saúde e prevenção de agravos na família e na comunidade. A formação técnica do agente comunitário de saúde incluiu três módulos, totalizando uma carga horária de 1.200 horas. No primeiro módulo, foram contemplados temas como a contextualização, aproximação e dimensionamento do perfil profissional do agente; no segundo, a promoção da saúde e a prevenção de doenças dirigidas a grupos específicos e doenças prevalentes; e no terceiro, a promoção, a prevenção e o monitoramento das situações em Vigilância em Saúde. Para esta formação, a Escola Técnica de Saúde do Tocantins optou pela descentralização das salas de aula (69 turmas em 18 polos formativos, atendendo a demanda dos 139 municípios do estado, facilitando a participação dos 2.219 alunos-servidores que concluíram o itinerário completo da formação.This report deals with the experience of the Technical School of Health of Tocantins in the educational process of technical training of community health agents. It presents how these agents were trained to work with the multidisciplinary health care team in a critical, reflective, and ethical reality changing professional approach. The report also highlights the development of actions of social integration, health promotion and the prevention of disorders in the family and community. Technical training of community health agents includes three modules, with a total workload of 1,200 hours. In the first module issues such as background, approach and design of

  1. Heterogeneous Causal Effects and Sample Selection Bias

    DEFF Research Database (Denmark)

    Breen, Richard; Choi, Seongsoo; Holm, Anders

    2015-01-01

    The role of education in the process of socioeconomic attainment is a topic of long standing interest to sociologists and economists. Recently there has been growing interest not only in estimating the average causal effect of education on outcomes such as earnings, but also in estimating how...... causal effects might vary over individuals or groups. In this paper we point out one of the under-appreciated hazards of seeking to estimate heterogeneous causal effects: conventional selection bias (that is, selection on baseline differences) can easily be mistaken for heterogeneity of causal effects...

  2. Causal ubiquity in quantum physics. A superluminal and local-causal physical ontology

    Energy Technology Data Exchange (ETDEWEB)

    Neelamkavil, Raphael

    2014-07-01

    A fixed highest criterial velocity (of light) in STR (special theory of relativity) is a convention for a layer of physical inquiry. QM (Quantum Mechanics) avoids action-at-a-distance using this concept, but accepts non-causality and action-at-a-distance in EPR (Einstein-Podolsky-Rosen-Paradox) entanglement experiments. Even in such allegedly [non-causal] processes, something exists processually in extension-motion, between the causal and the [non-causal]. If STR theoretically allows real-valued superluminal communication between EPR entangled particles, quantum processes become fully causal. That is, the QM world is sub-luminally, luminally and superluminally local-causal throughout, and the Law of Causality is ubiquitous in the micro-world. Thus, ''probabilistic causality'' is a merely epistemic term.

  3. Causal ubiquity in quantum physics. A superluminal and local-causal physical ontology

    International Nuclear Information System (INIS)

    A fixed highest criterial velocity (of light) in STR (special theory of relativity) is a convention for a layer of physical inquiry. QM (Quantum Mechanics) avoids action-at-a-distance using this concept, but accepts non-causality and action-at-a-distance in EPR (Einstein-Podolsky-Rosen-Paradox) entanglement experiments. Even in such allegedly [non-causal] processes, something exists processually in extension-motion, between the causal and the [non-causal]. If STR theoretically allows real-valued superluminal communication between EPR entangled particles, quantum processes become fully causal. That is, the QM world is sub-luminally, luminally and superluminally local-causal throughout, and the Law of Causality is ubiquitous in the micro-world. Thus, ''probabilistic causality'' is a merely epistemic term.

  4. Quantum retrodiction and causality principle

    International Nuclear Information System (INIS)

    Quantum mechanics is factually a predictive science. But quantum retrodiction may also be needed, e.g., for the experimental verification of the validity of the Schroedinger equation for the wave function in the past if the present state is given. It is shown that in the retrodictive analog of the prediction the measurement must be replaced by another physical process called the retromeasurement. In this process, the reduction of a state vector into eigenvectors of a measured observable must proceed in the opposite direction of time as compared to the usual reduction. Examples of such processes are unknown. Moreover, they are shown to be forbidden by the causality principle stating that the later event cannot influence the earlier one. So quantum retrodiction seems to be unrealizable. It is demonstrated that the approach to the retrodiction given by S.Watanabe and F.Belinfante must be considered as an unsatisfactory ersatz of retrodicting. 20 refs., 3 figs

  5. Comparison theorems for causal diamonds

    CERN Document Server

    Berthiere, Clement; Solodukhin, Sergey N

    2015-01-01

    We formulate certain inequalities for the geometric quantities characterizing causal diamonds in curved and Minkowski spacetimes. These inequalities involve the red-shift factor which, as we show explicitly in the spherically symmetric case, is monotonic in the radial direction and it takes its maximal value at the centre. As a byproduct of our discussion we re-derive Bishop's inequality without assuming the positivity of the spatial Ricci tensor. We then generalize our considerations to arbitrary, static and not necessarily spherically symmetric, asymptotically flat spacetimes. In the case of spacetimes with a horizon our generalization involves the so-called {\\it domain of dependence}. The respective volume, expressed in terms of the duration measured by a distant observer compared with the volume of the domain in Minkowski spacetime, exhibits behaviours which differ if $d=4$ or $d>4$. This peculiarity of four dimensions is due to the logarithmic subleading term in the asymptotic expansion of the metric nea...

  6. The Power of Causal Beliefs and Conflicting Evidence on Causal Judgments and Decision Making

    Science.gov (United States)

    Garcia-Retamero, Rocio; Muller, Stephanie M.; Catena, Andres; Maldonado, Antonio

    2009-01-01

    In two experiments, we investigated the relative impact of causal beliefs and empirical evidence on both decision making and causal judgments, and whether this relative impact could be altered by previous experience. 2. Selected groups of participants in both experiments received pre-training with either causal or neutral cues, or no pre-training…

  7. As escolhas públicas orçamentárias federais no PPA 2008-2011: uma análise da perspectiva do modelo principal-agente

    Directory of Open Access Journals (Sweden)

    Giovanni Pacelli Carvalho Lustosa da Costa

    2013-10-01

    Full Text Available O objetivo deste estudo é analisar o comportamento assumido pelo Executivo e pelo Legislativo durante a gestão do PPA 2008-2011 da perspectiva do modelo principal-agente. Por meio da aplicação dos testes de Friedman, Kendall e Spearman e tendo como objeto empírico todos os programas constantes no PPA 2008-2011, observou-se que entre 2008 e 2011: as etapas de Elaboração e de Execução Orçamentária e Financeira da Lei Orçamentária Anual, cujo ator principal é o Poder Executivo, apresentaram concordância muito forte; enquanto a etapa de Discussão, Votação e Aprovação, cujo ator principal é o Poder Legislativo, apresentou concordância moderada. Quando se considerou a interação no mesmo ciclo entre todas as etapas, a concordância foi menor. Além disso, como resultado mais expressivo do estudo, identificou-se que a relação externa (entre governo e cidadãos possui concordância maior que a relação interna (entre políticos e burocratas.

  8. Extrusão de compósitos de PP com fibras curtas de coco: efeito da temperatura e agentes de acoplamento Extrusion of PP composites with short coir fibers: effect of temperature and coupling agents

    Directory of Open Access Journals (Sweden)

    Evelise F. Santos

    2010-09-01

    Full Text Available Compósitos de PP com fibras curtas de coco foram preparados em extrusora, com dois perfis de temperatura, visando avaliar o efeito compatibilizante de PP modificado com vinilalcoxisilano e com anidrido maleico. Foi verificado que os dois agentes de acoplamento melhoraram o módulo elástico, a tensão máxima e a resistência à absorção de água quando os materiais foram processados utilizando-se um perfil de temperaturas mais elevadas. A morfologia dos compósitos também ficou mais homogênea na presença dos agentes de acoplamento, especialmente naqueles processados na temperatura mais alta. Esses resultados indicam que a temperatura é uma variável fundamental no estabelecimento das interações envolvendo os processos de compatibilização.PP composites filled with coir short fibers were prepared in an extruder using two temperature profiles. The objective was to evaluate the compatibilizing effect of PP modified with vinylsilane and with maleic anhydride. Both coupling agents improved elastic modulus, tensile strength and water absorption resistance when the materials were processed at the highest temperature profile. The composite morphology was more homogeneous in the presence of the coupling agents, mainly in the composites processed at the highest temperatures. These results indicate that temperature is a key variable for the establishment of the interactions involved in the coupling processes.

  9. Partial chemical characterization of antigenic preparations of chromoblastomycosis agents Caracterização química parcial de preparações antigênicas de agentes da cromoblastomicose

    OpenAIRE

    Tania Fraga BARROS; de Resende, Maria Aparecida

    1999-01-01

    Antigenic preparations (saline, methylic, metabolic and exoantigens) of four agents of chromoblastomycosis, Fonsecaea pedrosoi, Phialophora verrucosa, Cladophialophora (Cladosporium) carrionii and Rhinocladiella aquaspersa were obtained. Partial chemical characterization of these antigenic preparations was obtained by determination of the levels of total lipids, protein, and carbohydrates, and identification of the main sterols and carbohydrates. Methylic antigens presented the highest lipid ...

  10. À descoberta da sociedade civil regional: Os parceiros sociais, agentes das políticas regionais financiadas pela União Europeia

    Directory of Open Access Journals (Sweden)

    Elisabeth Dupoirier

    2012-10-01

    Full Text Available A presença de interlocutores da sociedade civil junto da acção pública é estimulada pelas normas europeias, que reforçam o papel dos “parceiros sociais” nos vários patamares da governação. Para as regiões francesas, a possibilidade de associar às suas políticas a expertise e representatividade social dos grupos de interesse constitui um meio importante de legitimação e eficácia. O contexto regional é, todavia, pouco atractivo para os representantes da sociedade civil. Estes, com dificuldade em conciliar posições nos territórios e inibidos pela complexidade dos programas comunitários, preferem apostar no percurso institucional tradicional, privilegiando o relacionamento com o Estado e os departamentos. As regiões, por outro lado, vêem a nível territorial os parceiros sociais virar-se mais para as aglomerações urbanas.

  11. Spin foam models as energetic causal sets

    Science.gov (United States)

    Cortês, Marina; Smolin, Lee

    2016-04-01

    Energetic causal sets are causal sets endowed by a flow of energy-momentum between causally related events. These incorporate a novel mechanism for the emergence of space-time from causal relations [M. Cortês and L. Smolin, Phys. Rev. D 90, 084007 (2014); Phys. Rev. D 90, 044035 (2014)]. Here we construct a spin foam model which is also an energetic causal set model. This model is closely related to the model introduced in parallel by Wolfgang Wieland in [Classical Quantum Gravity 32, 015016 (2015)]. What makes a spin foam model also an energetic causal set is Wieland's identification of new degrees of freedom analogous to momenta, conserved at events (or four-simplices), whose norms are not mass, but the volume of tetrahedra. This realizes the torsion constraints, which are missing in previous spin foam models, and are needed to relate the connection dynamics to those of the metric, as in general relativity. This identification makes it possible to apply the new mechanism for the emergence of space-time to a spin foam model. Our formulation also makes use of Markopoulou's causal formulation of spin foams [arXiv:gr-qc/9704013]. These are generated by evolving spin networks with dual Pachner moves. This endows the spin foam history with causal structure given by a partial ordering of the events which are dual to four-simplices.

  12. Controlling for causally relevant third variables.

    Science.gov (United States)

    Goodie, Adam S; Williams, Cristina C; Crooks, C L

    2003-10-01

    In 3 experiments, the authors tested the conditions under which 3rd variables are controlled for in making causal judgments. The authors hypothesized that 3rd variables are controlled for when the 3rd variables are themselves perceived as causal. In Experiment 1, the participants predicted test performance after seeing information about wearing a lucky garment, taking a test-preparation course, and staying up late. The course (perceived as more causally relevant) was controlled for more than was the garment (perceived as less causally relevant) in assessing the effectiveness of staying up late. In Experiments 2 and 3, to obviate the many alternative accounts that arise from the realistic cover story of Experiment 1, participants predicted flowers' blooming after the presentation or nonpresentation of liquids. When one liquid was trained as causal, it was controlled for more in judging another liquid than when it was trained as neutral. Overall, stimuli perceived as causal were controlled for more when judging other stimuli. The authors concluded that the effect of perceived causal relevance on causal conditionalizing is real and normatively reasonable. PMID:14672103

  13. Causal processes and propensities in quantum mechanics

    Directory of Open Access Journals (Sweden)

    Mauricio SUÁREZ

    2010-01-01

    Full Text Available I offer an alternative interpretation of Van Fraassen's influential arguments against causal realism in quantum mechanics. These arguments provide in fact a good guide to the different causal models available for the Einstein-Podolsky-Rosen correlations, which in turn shed light on the nature of quantum propensities.

  14. Compact Representations of Extended Causal Models

    Science.gov (United States)

    Halpern, Joseph Y.; Hitchcock, Christopher

    2013-01-01

    Judea Pearl (2000) was the first to propose a definition of actual causation using causal models. A number of authors have suggested that an adequate account of actual causation must appeal not only to causal structure but also to considerations of "normality." In Halpern and Hitchcock (2011), we offer a definition of actual causation…

  15. mediation: R Package for Causal Mediation Analysis

    Directory of Open Access Journals (Sweden)

    Dustin Tingley

    2014-09-01

    Full Text Available In this paper, we describe the R package mediation for conducting causal mediation analysis in applied empirical research. In many scientific disciplines, the goal of researchers is not only estimating causal effects of a treatment but also understanding the process in which the treatment causally affects the outcome. Causal mediation analysis is frequently used to assess potential causal mechanisms. The mediation package implements a comprehensive suite of statistical tools for conducting such an analysis. The package is organized into two distinct approaches. Using the model-based approach, researchers can estimate causal mediation effects and conduct sensitivity analysis under the standard research design. Furthermore, the design-based approach provides several analysis tools that are applicable under different experimental designs. This approach requires weaker assumptions than the model-based approach. We also implement a statistical method for dealing with multiple (causally dependent mediators, which are often encountered in practice. Finally, the package also offers a methodology for assessing causal mediation in the presence of treatment noncompliance, a common problem in randomized trials.

  16. Causalities of the Taiwan Stock Market

    OpenAIRE

    Juhi-Lian Julian Ting

    2003-01-01

    Volatility, fitting with first order Landau expansion, stationarity, and causality of the Taiwan stock market (TAIEX) are investigated based on daily records. Instead of consensuses that consider stock market index change as a random time series we propose the market change as a dual time series consists of the index and the corresponding volume. Therefore, causalities between these two time series are investigated.

  17. Campbell's and Rubin's Perspectives on Causal Inference

    Science.gov (United States)

    West, Stephen G.; Thoemmes, Felix

    2010-01-01

    Donald Campbell's approach to causal inference (D. T. Campbell, 1957; W. R. Shadish, T. D. Cook, & D. T. Campbell, 2002) is widely used in psychology and education, whereas Donald Rubin's causal model (P. W. Holland, 1986; D. B. Rubin, 1974, 2005) is widely used in economics, statistics, medicine, and public health. Campbell's approach focuses on…

  18. Unpacking the causal chain of financial literacy

    OpenAIRE

    Carpena, Fenella; Cole, Shawn; Shapiro, Jeremy; Zia, Bilal

    2011-01-01

    A growing body of literature examines the causal impact of financial literacy on individual, household, and firm level outcomes. This paper unpacks the mechanism of impact by focusing on the first link in the causal chain. Specifically, it studies the experimental impact of financial literacy on three distinct dimensions of financial knowledge. The analysis finds that financial literacy do...

  19. Causal random geometry from stochastic quantization

    DEFF Research Database (Denmark)

    Ambjørn, Jan; Loll, R.; Westra, W.; Zohren, S.

    2010-01-01

     in this short note we review a recently found formulation of two-dimensional causal quantum gravity defined through Causal Dynamical Triangulations and stochastic quantization. This procedure enables one to extract the nonperturbative quantum Hamiltonian of the random surface model including the...

  20. Efetividade de programa de agentes comunitários na promoção da saúde bucal Efectividad del programa de agentes comunitarios en la promoción de la salud bucal Effectiveness of a community health worker program on oral health promotion

    OpenAIRE

    Paulo Frazão; Débora Marques

    2009-01-01

    OBJETIVO:Avaliar mudanças em conhecimentos, atitudes e acesso/utilização de serviços odontológicos decorrentes de um programa de promoção da saúde bucal com agentes comunitários de saúde. MÉTODOS:Um projeto de capacitação combinando ensino-aprendizagem, apoio e supervisão, foi desenvolvido entre os meses de julho de 2003 a agosto de 2004. As mudanças foram avaliadas por meio de entrevistas estruturadas em que participaram 36 agentes comunitários de saúde e uma amostra de 91 mulheres e mães, r...

  1. Granger causality in wall-bounded turbulence

    International Nuclear Information System (INIS)

    Granger causality is based on the idea that if a variable helps to predict another one, then they are probably involved in a causality relationship. This technique is based on the identification of a predictive model for causality detection. The aim of this paper is to use Granger causality to study the dynamics and the energy redistribution between scales and components in wall-bounded turbulent flows. In order to apply it on flows, Granger causality is generalized for snapshot-based observations of large size using linear-model identification methods coming from model reduction. Optimized DMD, a variant of the Dynamic Mode Decomposition, is considered for building a linear model based on snapshots. This method is used to link physical events and extract physical mechanisms associated to the bursting process in the logarithmic layer of a turbulent channel flow.

  2. Quantum-coherent mixtures of causal relations

    CERN Document Server

    MacLean, Jean-Philippe W; Spekkens, Robert W; Resch, Kevin J

    2016-01-01

    Understanding the causal influences that hold among the parts of a system is critical both to explaining that system's natural behaviour and to controlling it through targeted interventions. In a quantum world, understanding causal relations is equally important, but the set of possibilities is far richer. The two basic ways in which a pair of time-ordered quantum systems may be causally related are by a cause-effect mechanism or by a common cause acting on both. Here, we show that it is possible to have a coherent mixture of these two possibilities. We realize such a nonclassical causal relation in a quantum optics experiment and derive a set of criteria for witnessing the coherence based on a quantum version of Berkson's paradox. The interplay of causality and quantum theory lies at the heart of challenging foundational puzzles, such as Bell's theorem and the search for quantum gravity, but could also provide a resource for novel quantum technologies.

  3. O equívoco no discurso da inclusão: o funcionamento do conceito de diferença no depoimento de agentes educacionais The mistake in the inclusive discourse: the functioning of the concept of difference within the educational agents' statements

    Directory of Open Access Journals (Sweden)

    Juliana Santana Cavallari

    2010-01-01

    Full Text Available Este estudo se propõe a analisar o modo como o discurso da inclusão produz efeitos de verdade em nosso meio sócio-histórico, ao evocar outros domínios discursivos. Ancorada na perspectiva discursiva, perpassada pela psicanálise lacaniana, foram destacadas algumas regularidades nos depoimentos proferidos por agentes educacionais, durante palestras realizadas em um congresso sobre "inclusão e diversidade". Partindo da questão: como os conceitos de inclusão e diferença colocam os dizeres de agentes educacionais em funcionamento?, a análise do corpus discursivo evidenciou a aparente "necessidade" de aplicação do discurso da inclusão como eliminador das diferenças (físicas ou não, o que, imaginariamente, possibilitaria uma prática pedagógica mais justa e igualitária. Trata-se, portanto, de um equívoco de ordem ideológica, tendo em vista que a prática discursiva em questão não visa a incluir as diferenças ou tratá-las de modo singular, mas a criar identidades fixas, conservadoras e repetitivas.The purpose of this study is to analyze the way the discourse upon inclusive practices produces some effects of truth within our social and historical environment, by evoking other discursive domains. Through a discursive perspective, affected by the psychoanalysis, some regularities enunciated by educational agents, during speeches given at a Congress concerning inclusion and diversity, were pointed out. The analysis of the data was based on the following question: to what extent the concepts of difference and inclusion make the talk of educational agents meaningful? The results have stressed the "necessity" felt by the educational agents of applying the inclusive discourse to promote a fair and equal pedagogical practice. Taking into account that this kind of practice tends not to treat the differences in a singular way, it's possible to state that repetitive, traditional and permanent identities have been built within the

  4. Influência do agente de cloração do catalisador à base de veodímio e da razão molar Cl: Nd na polimerização do butadieno Influence of the chlorinating agent of neodymium based catalysts and Cl: Nd molar ratio on butadiene polymerization

    Directory of Open Access Journals (Sweden)

    Cintia N. Ferreira

    2009-06-01

    Full Text Available Neste trabalho foi utilizado um sistema catalítico composto por hidreto de diisobutilalumínio (DIBAH, versatato de neodímio (NdV e um agente de cloração para avaliar a influência da fonte de cloro e da razão molar Cl:Nd nas características da reação de polimerização (conversão e constante de velocidade de propagação e do polibutadieno (massa molecular e microestrutura. Os agentes de cloração estudados foram cloreto de t-butila (t-BuCl, sesquicloreto de etilalumínio (EASC e cloreto de dietilalumínio (DEAC. As razões molares Cl:Nd utilizadas foram: 1:1, 3:1 e 5:1 para o t-BuCl; 0,5:1, 1:1 e 3:1 para o EASC e 1:1, 1,5:1, 3:1 e 5:1 para o DEAC. Foi observada a existência, para cada agente de cloração, de um valor ótimo de razão molar Cl:Nd para o qual a conversão foi máxima. O DEAC apresentou uma maior conversão em relação aos outros agentes de cloração; em contrapartida, o t-BuCl produziu polibutadienos com maior teor de unidades 1,4-cis e maior massa molecular (n e wIn this work catalyst systems consisting of diisobutylaluminium hydride (DIBAH, neodymium versatate (NdV and a chlorinating agent were employed to study the influence of the chloride source and Cl:Nd molar ratio on 1,3-butadiene polymerization and polybutadiene's characteristics (molecular weight and microstructure. The chloride sources studied were t-butyl chloride, ethylaluminium sesquichloride (EASC and diethylaluminium chloride (DEAC. The Cl:Nd molar ratios used were 1:1, 3:1 e 5:1 for t-butyl chloride; 0.5:1, 1:1 and 3:1 for EASC and 1:1, 1.5:1, 3:1 and 5:1 for DEAC. A maximum value of Cl:Nd molar ratio exists. Moreover, DEAC showed to be more reactive than EASC and t-BuCl but t-BuCl produced higher molecular weight and cis-1,4 units contents.

  5. Causal ubiquity in quantum physics a superluminal and local-causal physical ontology

    CERN Document Server

    Neelamkavil, Raphael

    2014-01-01

    A fixed highest criterial velocity (of light) in STR (special theory of relativity) is a convention for a layer of physical inquiry. QM (Quantum Mechanics) avoids action-at-a-distance using this concept, but accepts non-causality and action-at-a-distance in EPR (Einstein-Podolsky-Rosen-Paradox) entanglement experiments. Even in such allegedly non-causal processes, something exists processually in extension-motion, between the causal and the non-causal. If STR theoretically allows real-valued superluminal communication between EPR entangled particles, quantum processes become fully causal. That

  6. Bioprospecting endophytic bacteria for biological control of coffee leaf rust Bioprospecção de bactérias endofíticas como agentes de biocontrole da ferrugem do cafeeiro

    Directory of Open Access Journals (Sweden)

    Humberto Franco Shiomi

    2006-02-01

    Full Text Available Suppression of plant diseases due to the action of endophytic microorganisms has been demonstrated in several pathosystems. Experiments under controlled conditions involving endophytic bacteria isolated from leaves and branches of Coffea arabica L and Coffea robusta L were conducted with the objective of evaluating the inhibition of germination of Hemileia vastatrix Berk. & Br., race II, urediniospores and the control of coffee leaf rust development in tests with leaf discs, detached leaves, and on potted seedling of cv. Mundo Novo. The endophytic bacterial isolates tested proved to be effective in inhibiting urediniospore germination and/or rust development, with values above 50%, although the results obtained in urediniospore germination tests were inferior to the treatment with fungicide propiconazole. Endophytic isolates TG4-Ia, TF2-IIc, TF9-Ia, TG11-IIa, and TF7-IIa, demonstrated better coffee leaf rust control in leaf discs, detached leaves, and coffee plant tests. The endophytic isolates TG4-Ia and TF9-Ia were identified as Bacillus lentimorbus Dutky and Bacillus cereus Frank. & Frank., respectively. Some endophytic bacterial isolates were effective in controlling the coffee leaf rust, although some increased the severity of the disease. Even though a relatively small number of endophytic bacteria were tested, promising results were obtained regarding the efficiency of coffee leaf rust biocontrol. These selected agents appears to be an alternative for future replacement of chemical fungicide.Supressão de doenças de plantas por microrganismos endofíticos tem sido demonstrada em diversos patossistemas. Neste trabalho foram selecionados isolados de bactérias endofíticas de folhas e ramos de cafeeiro com potencial para o controle biológico da ferrugem do cafeeiro, pois é conhecido que esses microrganismos podem possuir essa característica. Bactérias endofíticas isoladas previamente de folhas e ramos de Coffea arabica L e Coffea

  7. Stress ocupacional em profissionais de segurança pública: um estudo com militares da Guarda Nacional Republicana Occupational stress in professionals of public security: a study with military agents of the Republican National Guard

    Directory of Open Access Journals (Sweden)

    Jorge M. P. Afonso

    2009-01-01

    Full Text Available Este trabalho analisa o "stress" ocupacional em 95 militares da Guarda Nacional Republicana Portuguesa. Para tal, utilizámos um protocolo de avaliação com medidas do "stress" global, "burnout", "coping" proactivo, comprometimento organizacional, satisfação com a vida e satisfação/realização profissional. Os indicadores de fidelidade e validade dos instrumentos foram muito aceitáveis. Os resultados de "burnout" por dimensão apontaram níveis apreciáveis de exaustão emocional (12%, seguidos do cinismo (10% e da baixa eficácia profissional (8% (mas nenhum participante registou valores de "burnout" nas três dimensões, em simultâneo, observando-se também variáveis distintas na predição destas três áreas. A análise discriminante entre subgrupos da amostra permitiu verificar dois aspectos principais: (a menores níveis de comprometimento organizacional e maior utilização de "coping" proactivo nos militares mais novos e/ou inexperientes e (b maior desejo de abandonar o emprego/trabalho bem como maior cinismo parecem identificar os profissionais mais velhos e/ou mais experientes. No final, os autores discutem a importância de a investigação futura analisar os efeitos da maior tendência para o cinismo com o aumento da idade dos participantes e os efeitos do menor comprometimento organizacional por parte dos mais novos em termos da sua eficácia profissional.This work analyzes occupational stress in 95 Portuguese military agents of the Republican National Guard. We applied an evaluation protocol with measures of global stress, burnout, proactive coping, organizational commitment, satisfaction with life, and professional satisfaction/accomplishment. The fidelity and validity results of the instruments were very acceptable. The results of burnout pointed out a remarkable level of emotional exhaustion (12% followed by cynicism (10% and low professional effectiveness (8% (but we have not found any participant with burnout values

  8. Um projeto de intervenção social visto pelos seus agentes: estudo psicossocial do Programa de Saúde da Família

    Directory of Open Access Journals (Sweden)

    Ana Maria Blanques

    2010-01-01

    Full Text Available O Programa de Saúde da Família (PSF foi escolhido como objeto deste estudo por ser um projeto de intervenção social que pretende promover maior autonomia da população para resolver problemas relativos à saúde no território. O material obtido em entrevistas com os profissionais foi analisado por meio de categorias agrupadas em dois blocos temáticos: concepção do trabalho - aquelas que se referem às atividades, e de sujeito - em que se reúnem as ideias sobre as pessoas envolvidas. Os conteúdos revelam que o programa não atinge as mudanças previstas. O conceito de território é incipiente, a participação é precária e as doenças se mantêm em lugar privilegiado. As pessoas da população são referidas num conjunto que é caracterizado por faltas, carências, necessidades e, em muitos casos, são identificadas aos próprios entrevistados. A ajuda mobiliza as ações e é o eixo a partir do qual os atores compreendem sua própria atuação.

  9. Comunicação no Programa Saúde da Família: o agente de saúde como elo integrador entre a equipe e a comunidade Communication in the Family Health Program: the health agent as an integrating link between the team and the community

    Directory of Open Access Journals (Sweden)

    Andréia dos Santos Cardoso

    2010-06-01

    Full Text Available Este estudo é parte do projeto "Avaliação da Estratégia da Saúde da Família no Município do Rio de Janeiro", desenvolvido na Universidade Estácio de Sá com apoio do Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq. Buscou identificar e analisar a percepção dos agentes comunitários de saúde (ACS quanto aos seus principais interlocutores, o grau de impacto destes interlocutores e as formas de comunicação predominantes no seu processo de trabalho. É um estudo descritivo, de abordagem qualitativa, com base em categorias teórico-metodológicas da educação popular e do modelo de comunicação do mercado simbólico. Os dados foram coletados em quatro equipes, de duas unidades do Programa Saúde da Família. Os mapas de comunicação elaborados com os ACS identificam o grupo de apoio técnico, a equipe técnica, os próprios ACS e os moradores antigos da comunidade como seus principais interlocutores. A comunicação com os demais profissionais da equipe é percebida de forma predominantemente verticalizada e com traços de autoritarismo. Os resultados revelam a importância de ampliação do diálogo e da negociação na comunicação estabelecida no interior da equipe e com a comunidade.This study is part of the project Evaluation of the Family Health Strategy in Rio de Janeiro, developed at Estácio de Sá University with support of the National Advice of Scientific and Technological Development (CNPq. The study aimed to identify and analyze the perception of the health communitarian agents (HCA about their main interlocutors, the impact of these interlocutors and the predominant communication forms in their work process. It is a descriptive study, with a qualitative approach, based on theoretical-methodological categories of the popular education and the symbolic market communication model. The data was collected in four teams of the Family Health Program. The results show the communication maps elaborated

  10. Causal localizations in relativistic quantum mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Castrigiano, Domenico P. L., E-mail: castrig@ma.tum.de; Leiseifer, Andreas D., E-mail: andreas.leiseifer@tum.de [Fakultät für Mathematik, TU München, Boltzmannstraße 3, 85747 Garching (Germany)

    2015-07-15

    Causal localizations describe the position of quantum systems moving not faster than light. They are constructed for the systems with finite spinor dimension. At the center of interest are the massive relativistic systems. For every positive mass, there is the sequence of Dirac tensor-localizations, which provides a complete set of inequivalent irreducible causal localizations. They obey the principle of special relativity and are fully Poincaré covariant. The boosters are determined by the causal position operator and the other Poincaré generators. The localization with minimal spinor dimension is the Dirac localization. Thus, the Dirac equation is derived here as a mere consequence of the principle of causality. Moreover, the higher tensor-localizations, not known so far, follow from Dirac’s localization by a simple construction. The probability of localization for positive energy states results to be described by causal positive operator valued (PO-) localizations, which are the traces of the causal localizations on the subspaces of positive energy. These causal Poincaré covariant PO-localizations for every irreducible massive relativistic system were, all the more, not known before. They are shown to be separated. Hence, the positive energy systems can be localized within every open region by a suitable preparation as accurately as desired. Finally, the attempt is made to provide an interpretation of the PO-localization operators within the frame of conventional quantum mechanics attributing an important role to the negative energy states.

  11. Mining Causality for Explanation Knowledge from Text

    Institute of Scientific and Technical Information of China (English)

    Chaveevan Pechsiri; Asanee Kawtrakul

    2007-01-01

    Mining causality is essential to provide a diagnosis. This research aims at extracting the causality existing within multiple sentences or EDUs (Elementary Discourse Unit). The research emphasizes the use of causality verbs because they make explicit in a certain way the consequent events of a cause, e.g., "Aphids suck the sap from rice leaves. Then leaves will shrink. Later, they will become yellow and dry.". A verb can also be the causal-verb link between cause and effect within EDU(s), e.g., "Aphids suck the sap from rice leaves causing leaves to be shrunk" ("causing" is equivalent to a causal-verb link in Thai). The research confronts two main problems: identifying the interesting causality events from documents and identifying their boundaries. Then, we propose mining on verbs by using two different machine learning techniques, Naive Bayes classifier and Support Vector Machine. The resulted mining rules will be used for the identification and the causality extraction of the multiple EDUs from text. Our multiple EDUs extraction shows 0.88 precision with 0.75 recall from Na'ive Bayes classifier and 0.89 precision with 0.76 recall from Support Vector Machine.

  12. Causal localizations in relativistic quantum mechanics

    International Nuclear Information System (INIS)

    Causal localizations describe the position of quantum systems moving not faster than light. They are constructed for the systems with finite spinor dimension. At the center of interest are the massive relativistic systems. For every positive mass, there is the sequence of Dirac tensor-localizations, which provides a complete set of inequivalent irreducible causal localizations. They obey the principle of special relativity and are fully Poincaré covariant. The boosters are determined by the causal position operator and the other Poincaré generators. The localization with minimal spinor dimension is the Dirac localization. Thus, the Dirac equation is derived here as a mere consequence of the principle of causality. Moreover, the higher tensor-localizations, not known so far, follow from Dirac’s localization by a simple construction. The probability of localization for positive energy states results to be described by causal positive operator valued (PO-) localizations, which are the traces of the causal localizations on the subspaces of positive energy. These causal Poincaré covariant PO-localizations for every irreducible massive relativistic system were, all the more, not known before. They are shown to be separated. Hence, the positive energy systems can be localized within every open region by a suitable preparation as accurately as desired. Finally, the attempt is made to provide an interpretation of the PO-localization operators within the frame of conventional quantum mechanics attributing an important role to the negative energy states

  13. Trabalhador de enfermagem: agente colaborador no cumprimento da missão institucional Trabajador de enfermería: agente colaborador del cumplimento de la misión institucional Worker of nursing: collaborating agent in the execution of the institutional mission

    Directory of Open Access Journals (Sweden)

    Diana Cecagno

    2005-02-01

    Full Text Available Este estudo teve como propósito investigar estratégias que podem ser utilizadas, pelas instituições de saúde, sob ao olhar do enfermeiro, para motivar/valorizar e promover a capacitação do trabalhador de enfermagem, enquanto agente colaborador da instituição em busca do cumprimento de sua missão. Para a concretização do mesmo, investimos em uma metodologia qualitativa, descritiva e exploratória, cujo instrumento de pesquisa, semi-estruturado, foi aplicado a 15 enfermeiros, sendo garantido, aos mesmos, os preceitos éticos e legais cabíveis nesse estudo. Ao concluirmos este estudo constatamos que as principais estratégias que podem ser utilizadas, sob a ótica do enfermeiro, para motivar/valorizar e promover a capacitação do trabalhador de enfermagem, dizem respeito à necessidade de diálogo e a promoção do crescimento profissional.Esto estudio tuve como propósito investigar las estratégicas que puede usarse, pelas instituciones de salud, conforme la mirada de la enfermera, para motivar/valorizar y promover la capacitación del trabajador de enfermería, mientras agente colaborador de la institución en busca del cumplimento de misión. Para la concretización del mismo, nosotros invertimos en una metodología de carácter cualitativo, descriptivo y exploratorio cuyo instrumento de pesquisa, semi-estructurado, fue aplicado a 15 enfermeras, siendo garantido, al los mismos, los mandatos éticos y legales caviléis en ese estudio. Al concluirmos este estudio verificamos que las estrategias principales que pueden usarse, pelas instituciones de salud, conforme la mirada de los enfermeros, para el motivar/valorizar y promover la capacitación del trabajador de enfermería, dicen repecho a la necesidad del diálogo y la promoción del crecimiento profesional.The study aimed to investigate the strategy that can be used by health institutions, with respect to the nurse's optics, to motivate/value and to promote the nursing worker

  14. Causality and momentum conservation from relative locality

    Science.gov (United States)

    Amelino-Camelia, Giovanni; Bianco, Stefano; Brighenti, Francesco; Buonocore, Riccardo Junior

    2015-04-01

    Theories involving curved momentum space, which recently became a topic of interest in the quantum-gravity literature, can, in general, violate many apparently robust aspects of our current description of the laws of physics, including relativistic invariance, locality, causality, and global momentum conservation. Here, we explore some aspects of the pathologies arising in generic theories involving curved momentum space for what concerns causality and momentum conservation. However, we also report results suggesting that when momentum space is maximally symmetric, and the theory is formulated relativistically, most notably including translational invariance with the associated relativity of spacetime locality, momentum is globally conserved and there is no violation of causality.

  15. Causal localizations in relativistic quantum mechanics

    International Nuclear Information System (INIS)

    Sufficient and necessary conditions for causal localizations of massive relativistic systems are developed. It is proven that the Dirac- and the Dirac tensor-system are up to unitary equivalence the only irreducible causal localizations with finite spinor dimension which have a massive relativistic extension. A formula for this extension is given. The existence of arbitrarily good localized states of positive energy is shown. In the context of the causality condition a Paley-Wiener theorem for bounded measurable matrix-valued functions is proven.

  16. The CMB in a Causal Set Universe

    CERN Document Server

    Zuntz, Joe

    2007-01-01

    We discuss Cosmic Microwave Background constraints on the causal set theory of quantum gravity, which has made testable predictions about the nature of dark energy. We flesh out previously discussed heuristic constraints by showing how the power spectrum of causal set dark energy fluctuations can be found from the overlap volumes of past light cones of points in the universe. Using a modified Boltzmann code we put constraints on the single parameter of the theory that are somewhat stronger than previous ones. We conclude that causal set theory cannot explain late-time acceleration without radical alterations to General Relativity.

  17. Causality in 3D Massive Gravity Theories

    CERN Document Server

    Edelstein, Jose D; Kilicarslan, Ercan; Leoni, Matias; Tekin, Bayram

    2016-01-01

    We study the constraints coming from local causality requirement in various 2+1 dimensional dynamical theories of gravity. In Topologically Massive Gravity, with a single parity noninvariant massive degree of freedom, and in New Massive Gravity, with two massive spin-$2$ degrees of freedom, causality and unitarity are compatible with each other and they both require the Newton's constant to be negative. In their extensions, such as the Born-Infeld gravity and the minimal massive gravity the situation is similar and quite different from their higher dimensional counterparts, such as quadratic (e.g., Einstein-Gauss-Bonnet) or cubic theories, where causality and unitarity are in conflict.

  18. Comparação da superfície do esmalte antes e após clareamento com dois diferentes agentes: estudo clínico

    Directory of Open Access Journals (Sweden)

    Virgínia Teichmann Espina

    2008-01-01

    Full Text Available The purpose of this study was to compare of enamel surface before and after bleaching with two different agents. Twenty subjects were selected and divided in two groups: Group 1- treated with the night guard vital bleaching using 10% carbamide peroxide (Whiteness Perfect and Group 2- treated with the in-offi ce technique using 35% hydrogen peroxide (Whiteness HP. Epoxi resin replicas obtained from the maxillary central incisors, before, immediately after and thirty days after the bleaching procedure. All replicas were photography in scanning electron microscopy and examined for one expert and blind examiner taken in scores: 1- surface without alteration 2- surface with alteration. This study demonstrated that bleaching treatment using both agents causes effect on namel surface, but these are partially reverted in thirty days.

  19. A Tecnologia da Informação como Agente de Mudança no Perfil do Profissional de Secretariado

    Directory of Open Access Journals (Sweden)

    Francisca Janete Adelino

    2012-12-01

    Full Text Available Ao longo dos anos, a profissão de secretariado passou por mudanças significativas, desde a perda de seu caráter informal, à regulamentação como profissão. A partir da automação dos escritórios, as antigas ferramentas – tais como o carbono, a máquina de escrever e o telex – foram substituídas por modernas impressoras, computadores, Internet, dentre outras.Assim, o objetivo geral deste trabalho é identificar o impacto da TI nas atividades de rotina do profissional de secretariado para ter uma imagem mais aproximada do quão aquela influenciou na mudança do perfil deste e de que forma essa mudança ocorreu.Para a realização desta pesquisa, foi utilizada a metodologia de caráter descritivo e exploratório. Para tanto, foram utilizados questionários estruturados com questões objetivas e subjetivas a respeito das práticas adotadas no dia a dia do profissional e das influências que a TI exerce sobre seu trabalho. Os resultados apontam que o secretariado de hoje em nada lembra aquele escriba submisso sem poder decisório e reativo. O novo profissional mostra-se proativo, capaz de tomar decisões de forma mais assertiva, rápido e respaldado pela capacidade de liderança quando da ausência de um superior hierárquico, assume o papel de cogestor entre os diferentes públicos envolvidos no processo administrativo.DOI:10.7769/gesec.v3i2.165

  20. Domain-specific perceptual causality in children depends on the spatio-temporal configuration, not motion onset

    Directory of Open Access Journals (Sweden)

    Anne eSchlottmann

    2013-07-01

    Full Text Available Humans, even babies, perceive causality when one shape moves briefly and linearly after another. Motion timing is crucial in this and causal impressions disappear with short delays between motions. However, the role of temporal information is more complex: It is both a cue to causality and a factor that constrains processing. It affects ability to distinguish causality from non-causality, and social from mechanical causality. Here we study both issues with 3- to 7-year-olds and adults who saw two computer-animated squares and chose if a picture of mechanical, social or non-causality fit each event best. Prior work fit with the standard view that early in development, the distinction between the social and physical domains depends mainly on whether or not the agents make contact, and that this reflects concern with domain-specific motion onset, in particular, whether the motion is self-initiated or not. The present experiments challenge both parts of this position. In Experiments 1 and 2, we showed that not just spatial, but also animacy and temporal information affect how children distinguish between physical and social causality. In Experiments 3 and 4 we showed that children do not seem to use spatio-temporal information in perceptual causality to make inferences about self- or other-initiated motion onset. Overall, spatial contact may be developmentally primary in domain-specific perceptual causality in that it is processed easily and is dominant over competing cues, but it is not the only cue used early on and it is not used to infer motion onset. Instead, domain-specific causal impressions may be automatic reactions to specific perceptual configurations, with a complex role for temporal information.

  1. Who is the dynamic duo? How infants learn about the identity of objects in a causal chain.

    Science.gov (United States)

    Rakison, David H; Smith, Gabriel Tobin; Ali, Areej

    2016-03-01

    Four experiments investigated infants' and adults' knowledge of the identity of objects in a causal sequence of events. In Experiments 1 and 2, 18- and 22-month-olds in the visual habituation procedure were shown a 3-step causal chain event in which the relation between an object's part (dynamic or static) and its causal role was either consistent or inconsistent with the real-world. In Experiment 3, 22-month-olds were tested with a delayed launching causal chain in which the second object, rather than the first, was the agent of the outcome. In Experiment 4, adults were shown the same events and were asked to judge whether the first or second object in the causal chain was animate or inanimate. Experiments 1 and 2 revealed that 18-month-olds were unconstrained in the part-causal role relations they would encode, but 22-month-olds learned only those relations that were consistent with the real-world. Experiment 3 showed that 22-month-olds expect the second object in a delayed launching sequence to possess a dynamic, moving part. Experiment 4 showed that adults expect the first object of a causal chain to be animate and the second object to be inanimate. The results are discussed with regard to the developmental timetable for causal learning and the mechanisms for early concept acquisition. (PsycINFO Database Record PMID:26689760

  2. Causality, Knowledge and Coordination in Distributed Systems

    CERN Document Server

    Ben-Zvi, Ido

    2011-01-01

    Effecting coordination across remote sites in a distributed system is an essential part of distributed computing, and also an inherent challenge. In 1978, an analysis of communication in asynchronous systems was suggested by Leslie Lamport. Lamport's analysis determines a notion of temporal precedence, a sort of weak notion of time, which is otherwise missing in asynchronous systems. This notion has been extensively utilized in various applications. Yet the analysis is limited to systems that are asynchronous. In this thesis we go beyond by investigating causality in synchronous systems. In such systems, the boundaries of causal influence are not charted out exclusively by message passing. Here time itself, passing at a uniform (or almost uniform) rate for all processes, is also a medium by which causal influence may fan out. This thesis studies, and characterizes, the combinations of time and message passing that govern causal influence in synchronous systems. It turns out that knowledge based analysis [FHMV...

  3. What becomes of a causal set

    CERN Document Server

    Wuthrich, Christian

    2015-01-01

    Unlike the relativity theory it seeks to replace, causal set theory has been interpreted to leave space for a substantive, though perhaps 'localized', form of 'becoming'. The possibility of fundamental becoming is nourished by the fact that the analogue of Stein's theorem from special relativity does not hold in causal set theory. Despite this, we find that in many ways, the debate concerning becoming parallels the well-rehearsed lines it follows in the domain of relativity. We present, however, some new twists and challenges. In particular, we show that a novel and exotic notion of becoming is compatible with causal sets. In contrast to the 'localized' becoming considered compatible with the dynamics of causal set theory by its advocates, our novel kind of becoming, while not answering to the typical A-theoretic demands, is 'global' and objective.

  4. Causality Between Urban Concentration and Environmental Quality

    Directory of Open Access Journals (Sweden)

    Amin Pujiati

    2015-08-01

    Full Text Available Population is concentrated in urban areas can cause the external diseconomies on environment if it exceeds the carrying capacity of the space and the urban economy. Otherwise the quality of the environment is getting better, led to the concentration of population in urban areas are increasingly high. This study aims to analyze the relationship of causality between the urban concentration and environmental quality in urban agglomeration areas. The data used in the study of secondary data obtained from the Central Bureau of statistics and the City Government from 2000 to 2013. The analytical method used is the Granger causality and descriptive. Granger causality study results showed no pattern of reciprocal causality, between urban concentration and the quality of the environment, but there unidirectional relationship between the urban concentration and environmental quality. This means that increasing urban concentration led to decreased environmental quality.

  5. Granger-causality maps of diffusion processes

    Science.gov (United States)

    Wahl, Benjamin; Feudel, Ulrike; Hlinka, Jaroslav; Wächter, Matthias; Peinke, Joachim; Freund, Jan A.

    2016-02-01

    Granger causality is a statistical concept devised to reconstruct and quantify predictive information flow between stochastic processes. Although the general concept can be formulated model-free it is often considered in the framework of linear stochastic processes. Here we show how local linear model descriptions can be employed to extend Granger causality into the realm of nonlinear systems. This novel treatment results in maps that resolve Granger causality in regions of state space. Through examples we provide a proof of concept and illustrate the utility of these maps. Moreover, by integration we convert the local Granger causality into a global measure that yields a consistent picture for a global Ornstein-Uhlenbeck process. Finally, we recover invariance transformations known from the theory of autoregressive processes.

  6. The Gravity Dual of Boundary Causality

    CERN Document Server

    Engelhardt, Netta

    2016-01-01

    In gauge/gravity duality, points which are not causally related on the boundary cannot be causally related through the bulk; this is the statement of boundary causality. By the Gao-Wald theorem, the averaged null energy condition in the bulk is sufficient to ensure this property. Here we proceed in the converse direction: we derive a necessary as well as sufficient condition for the preservation of boundary causality under perturbative (quantum or stringy) corrections to the bulk. The condition that we find is a (background-dependent) constraint on the amount by which light cones can "open" over all null bulk geodesics. We show that this constraint is weaker than the averaged null energy condition.

  7. Selecting appropriate cases when tracing causal mechanisms

    DEFF Research Database (Denmark)

    Beach, Derek; Pedersen, Rasmus Brun

    2016-01-01

    , ontological determinism, causal asymmetry and causal homogeneity and the importance of context. We then develop a set of case selection guidelines that are in methodological alignment with these underlying assumptions. Section 4 develops guidelines for research where the mechanism is the primary focus......The last decade has witnessed resurgence in the interest in studying the causal mechanisms linking causes and outcomes in the social sciences. This article explores the overlooked implications for case selection when tracing mechanisms using in-depth case studies. Our argument is that existing case...... selection guidelines are appropriate for research aimed at making cross-case claims about causal relationships, where case selection is primarily used to control for other causes. However, existing guidelines are not in alignment with case-based research that aims to trace mechanisms, where the goal is to...

  8. Quantum probability assignment limited by relativistic causality.

    Science.gov (United States)

    Han, Yeong Deok; Choi, Taeseung

    2016-01-01

    Quantum theory has nonlocal correlations, which bothered Einstein, but found to satisfy relativistic causality. Correlation for a shared quantum state manifests itself, in the standard quantum framework, by joint probability distributions that can be obtained by applying state reduction and probability assignment that is called Born rule. Quantum correlations, which show nonlocality when the shared state has an entanglement, can be changed if we apply different probability assignment rule. As a result, the amount of nonlocality in quantum correlation will be changed. The issue is whether the change of the rule of quantum probability assignment breaks relativistic causality. We have shown that Born rule on quantum measurement is derived by requiring relativistic causality condition. This shows how the relativistic causality limits the upper bound of quantum nonlocality through quantum probability assignment. PMID:26971717

  9. The Temporal Logic of Causal Structures

    CERN Document Server

    Kleinberg, Samantha

    2012-01-01

    Computational analysis of time-course data with an underlying causal structure is needed in a variety of domains, including neural spike trains, stock price movements, and gene expression levels. However, it can be challenging to determine from just the numerical time course data alone what is coordinating the visible processes, to separate the underlying prima facie causes into genuine and spurious causes and to do so with a feasible computational complexity. For this purpose, we have been developing a novel algorithm based on a framework that combines notions of causality in philosophy with algorithmic approaches built on model checking and statistical techniques for multiple hypotheses testing. The causal relationships are described in terms of temporal logic formulae, reframing the inference problem in terms of model checking. The logic used, PCTL, allows description of both the time between cause and effect and the probability of this relationship being observed. We show that equipped with these causal f...

  10. Causality and the semantics of provenance

    CERN Document Server

    Cheney, James

    2010-01-01

    Provenance, or information about the sources, derivation, custody or history of data, has been studied recently in a number of contexts, including databases, scientific workflows and the Semantic Web. Many provenance mechanisms have been developed, motivated by informal notions such as influence, dependence, explanation and causality. However, there has been little study of whether these mechanisms formally satisfy appropriate policies or even how to formalize relevant motivating concepts such as causality. We contend that mathematical models of these concepts are needed to justify and compare provenance techniques. In this paper we review a theory of causality based on structural models that has been developed in artificial intelligence, and describe work in progress on a causal semantics for provenance graphs.

  11. Causality and the Semantics of Provenance

    Directory of Open Access Journals (Sweden)

    James Cheney

    2010-06-01

    Full Text Available Provenance, or information about the sources, derivation, custody or history of data, has been studied recently in a number of contexts, including databases, scientific workflows and the Semantic Web. Many provenance mechanisms have been developed, motivated by informal notions such as influence, dependence, explanation and causality. However, there has been little study of whether these mechanisms formally satisfy appropriate policies or even how to formalize relevant motivating concepts such as causality. We contend that mathematical models of these concepts are needed to justify and compare provenance techniques. In this paper we review a theory of causality based on structural models that has been developed in artificial intelligence, and describe work in progress on using causality to give a semantics to provenance graphs.

  12. Causality and the Semantics of Provenance

    CERN Document Server

    Cheney, James

    2010-01-01

    Provenance, or information about the sources, derivation, custody or history of data, has been studied recently in a number of contexts, including databases, scientific workflows and the Semantic Web. Many provenance mechanisms have been developed, motivated by informal notions such as influence, dependence, explanation and causality. However, there has been little study of whether these mechanisms formally satisfy appropriate policies or even how to formalize relevant motivating concepts such as causality. We contend that mathematical models of these concepts are needed to justify and compare provenance techniques. In this paper we review a theory of causality based on structural models that has been developed in artificial intelligence, and describe work in progress on using causality to give a semantics to provenance graphs.

  13. Ten simple rules for dynamic causal modeling.

    NARCIS (Netherlands)

    Stephan, K.E.; Penny, W.D.; Moran, R.J.; Ouden, H.E.M. den; Daunizeau, J.; Friston, K.J.

    2010-01-01

    Dynamic causal modeling (DCM) is a generic Bayesian framework for inferring hidden neuronal states from measurements of brain activity. It provides posterior estimates of neurobiologically interpretable quantities such as the effective strength of synaptic connections among neuronal populations and

  14. A Causal Model for Diagnostic Reasoning

    Institute of Scientific and Technical Information of China (English)

    PENG Guoqiang; CHENG Hu

    2000-01-01

    Up to now, there have been many methods for knowledge representation and reasoning in causal networks, but few of them include the research on the coactions of nodes. In practice, ignoring these coactions may influence the accuracy of reasoning and even give rise to incorrect reasoning. In this paper, based on multilayer causal networks, the definitions on coaction nodes are given to construct a new causal network called Coaction Causal Network, which serves to construct a model of neural network for diagnosis followed by fuzzy reasoning, and then the activation rules are given and neural computing methods are used to finish the diagnostic reasoning. These methods are proved in theory and a method of computing the number of solutions for the diagnostic reasoning is given. Finally, the experiments and the conclusions are presented.

  15. Causal Structure and Birefringence in Nonlinear Electrodynamics

    OpenAIRE

    de Melo, C. A. M.; Medeiros, L. G.; Pompeia, P. J.(Instituto de Fomento e Coordenação Industrial, Departamento de Ciência e Tecnologia Aeroespacial, Praça Mal. Eduardo Gomes 50, 12228-901, São José dos Campos, SP , Brazil)

    2014-01-01

    We investigate the causal structure of general nonlinear electrodynamics and determine which Lagrangians generate an effective metric conformal to Minkowski. We also proof that there is only one analytic nonlinear electrodynamics presenting no birefringence.

  16. The Causal Effects of Father Absence

    OpenAIRE

    McLanahan, Sara; TACH, LAURA; Schneider, Daniel

    2013-01-01

    The literature on father absence is frequently criticized for its use of cross-sectional data and methods that fail to take account of possible omitted variable bias and reverse causality. We review studies that have responded to this critique by employing a variety of innovative research designs to identify the causal effect of father absence, including studies using lagged dependent variable models, growth curve models, individual fixed effects models, sibling fixed effects models, natural ...

  17. Inter-causal Independence and Heterogeneous Factorization

    OpenAIRE

    Zhang, Nevin Lianwen; Poole, David L

    2013-01-01

    It is well known that conditional independence can be used to factorize a joint probability into a multiplication of conditional probabilities. This paper proposes a constructive definition of inter-causal independence, which can be used to further factorize a conditional probability. An inference algorithm is developed, which makes use of both conditional independence and inter-causal independence to reduce inference complexity in Bayesian networks.

  18. Catastrophizing and Causal Beliefs in Whiplash

    OpenAIRE

    Buitenhuis, J.; de Jong, P J; Jaspers, J. P. C.; Groothoff, J. W.

    2008-01-01

    Study Design. Prospective cohort study. Objective. This study investigates the role of pain catastrophizing and causal beliefs with regard to severity and persistence of neck complaints after motor vehicle accidents. Summary of Background Data. In previous research on low back pain, somatoform disorders and chronic fatigue syndrome, pain catastrophizing and causal beliefs were found to be related to perceived disability and prognosis. Furthermore, it has been argued with respect to whiplash t...

  19. Causal Inference in Urban and Regional Economics

    OpenAIRE

    Nathaniel Baum-Snow; Fernando Ferreira

    2014-01-01

    Recovery of causal relationships in data is an essential part of scholarly inquiry in the social sciences. This chapter discusses strategies that have been successfully used in urban and regional economics for recovering such causal relationships. Essential to any successful empirical inquiry is careful consideration of the sources of variation in the data that identify parameters of interest. Interpretation of such parameters should take into account the potential for their heterogeneity as ...

  20. Causal transmission in reduced-form models

    OpenAIRE

    Vassili Bazinas; Bent Nielsen

    2015-01-01

    We propose a method to explore the causal transmission of a catalyst variable through two endogenous variables of interest. The method is based on the reduced-form system formed from the conditional distribution of the two endogenous variables given the catalyst. The method combines elements from instru- mental variable analysis and Cholesky decomposition of structural vector autoregressions. We give conditions for uniqueness of the causal transmission.

  1. Invited Commentary: Causal Diagrams and Measurement Bias

    OpenAIRE

    Hernán, Miguel A.; Cole, Stephen R.

    2009-01-01

    Causal inferences about the effect of an exposure on an outcome may be biased by errors in the measurement of either the exposure or the outcome. Measurement errors of exposure and outcome can be classified into 4 types: independent nondifferential, dependent nondifferential, independent differential, and dependent differential. Here the authors describe how causal diagrams can be used to represent these 4 types of measurement bias and discuss some problems that arise when using measured expo...

  2. A Definition and Graphical Representation for Causality

    OpenAIRE

    Heckerman, David; Shachter, Ross D.

    2013-01-01

    We present a precise definition of cause and effect in terms of a fundamental notion called unresponsiveness. Our definition is based on Savage's (1954) formulation of decision theory and departs from the traditional view of causation in that our causal assertions are made relative to a set of decisions. An important consequence of this departure is that we can reason about cause locally, not requiring a causal explanation for every dependency. Such local reasoning can be beneficial because i...

  3. Causales de ausencia de responsabilidad penal

    Directory of Open Access Journals (Sweden)

    Jaime Sandoval Fernández

    2003-01-01

    Full Text Available Este trabajo se ocupa de las causales de ausencia de responsabilidad penal, especialmente de aquellas que tienen efecto en el injusto. Como subtemas se delimita el concepto de responsabilidad penal y su ausencia. Se estudian las principales teorias a cerca de la relación tipicidad-antijuridicidad y su incidencia en el derecho penal colombiano. Por último contiene una propuesta acerca de cómo deberian agruparse las causales del arto 32 C. PlOO.

  4. Influência do tratamento químico da fibra de bananeira em compósitos de poli(etileno-co-acetato de vinila com e sem agente de expansão

    Directory of Open Access Journals (Sweden)

    Matheus V. G. Zimmermann

    2014-01-01

    Full Text Available Neste trabalho foi avaliada a influência do tratamento alcalino na fibra de bananeira (FB e seu uso como agente de reforço em compósitos expandidos de poli(etileno-co-acetato de vinila - EVA. O processo de mistura dos compósitos ocorreu em um misturador de rolos aberto e após conformados e expandidos em uma prensa aquecida com moldes de volumes variáveis. Os compósitos foram avaliados por suas propriedades mecânicas, térmicas e morfológicas. Os resultados indicam que o tratamento alcalino promove a extração de componentes menos estáveis na FB, tais como a lignina, hemicelulose, ceras e óleos de baixo peso molecular. O uso da FB nos compósitos proporciona um decréscimo das propriedades mecânicas de resistência à tração e rasgo em relação ao EVA puro devido a moderadas propriedades de interface polímero-fibra. Nos compósitos expandidos, as propriedades mecânicas decrescem com a diminuição da densidade em função da maior presença de espaços vazios no interior dos compósitos, porém as propriedades mecânicas específicas de resistência ao rasgo apresentaram melhores resultados com 10 pcr de FB em todos os moldes utilizados.

  5. Nanocompósitos de polietileno/argila bentonita nacional: influência da argila e do agente compatibilizante PE-g-MA nas propriedades mecânicas e de inflamabilidade Polyethylene/national bentonite clay nanocomposites: influence of clay and PE-g-MA coupling agent on the mechanical properties and flammability

    Directory of Open Access Journals (Sweden)

    Gustavo F. Brito

    2008-06-01

    Full Text Available Nanocompósitos de polietileno de alta densidade/argila bentonita nacional foram preparados por intercalação por fusão. A influência da adição da argila sem tratamento e da argila tratada com o sal quaternário de amônio Cetremide e do polietileno graftizado com anidrido maléico (PE-g-MA como agente compatibilizante foi avaliada. Os sistemas obtidos foram caracterizados por inflamabilidade, propriedades mecânicas e reológicas, difração de raios X e microscopia eletrônica de transmissão. Os resultados de difração de raios X e microscopia eletrônica de transmissão indicaram a obtenção de nanocompósitos com estruturas parcialmente esfoliadas e/ou intercaladas que conduziram ao aumento do módulo de elasticidade e do valor do torque. O teste de inflamabilidade mostrou que a adição da argila na matriz polimérica e a presença do PE-g-MA retardaram a velocidade de queima do sistema, ou seja, diminuíram a inflamabilidade do PE puro. Em geral, o sistema contendo o agente compatibilizante (PE-g-MA exibiu melhorias na estabilidade térmica e nanocompósitos parcialmente esfoliados foram formados, quando comparados à matriz de polietileno de alta densidade. O polietileno graftizado com anidrido maléico não apenas promoveu a esfoliação da argila, mas também facilitou a adesão carga-matriz, obtendo-se com isso melhorias nos resultados mecânicos do sistema.High density polyethylene/national bentonite clay nanocomposites were prepared with the melt intercalation technique. The effect of the clay without treatment and clay treated with quaternary ammonium salt Cetremide with polyethylene-graft-maleic anhydride as coupling agent was evaluated. The systems were characterized by flammability, mechanical and rheological properties, X ray diffraction and transmission electron microscopy. In general, the results of X ray diffraction and transmission electron microscopy showed partially exfoliated and/or intercalated structures with

  6. Influence of precipitating agent in the preparation of hydrous niobium oxide by the method of homogeneous precipitation; Influencia do agente precipitante na preparacao do oxido de niobio (V) hidratado pelo metodo da precipitacao em solucao homogenea

    Energy Technology Data Exchange (ETDEWEB)

    Tagliaferro, Geronimo Virginio; Silva, Maria Lcia C.P. da; Silva, Gilberto L.J.P. da [Faculdade de Engenharia Quimica de Lorena, SP (Brazil). Dept. de Engenharia Quimica]. E-mail: mlcaetano@dequi.faenquil.br

    2005-04-01

    This work reports the preparation, characterization and study of the ion exchange behavior of hydrous niobium oxide prepared by a homogeneous precipitation method. The precipitating agent was obtained in aqueous solution by thermal decomposition of urea or ammonium carbonate. The compounds were chemically and physically characterized by X-ray diffractometry, thermal analysis (TG/DTG), surface area measurements and ion exchange behavior with sodium. The materials prepared with ammonium carbonate presented a higher degree of crystallinity and better ion exchange capacity with sodium than materials prepared with urea. In the homogeneous precipitation method, materials were obtained with specific surface area of 123 - 224 m{sup 2} g{sup -1}. A variation of the preparation process produced hydrous niobium oxide with a different degree of hydration and specific surface area. This provided materials with different physico-chemical properties. (author)

  7. Alignment in the decision-making process between agents in biodiesel supply chains; Identificacao dos fatores e motivacoes relacionados ao processo de tomada de decisao dos diferentes agentes da cadeia produtiva do biodiesel do Rio Grande do Sul, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Rathmann, Regis; Santos, Omar Inacio Benedetti [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE). Programa de Planejamento Energetico; Padula, Antonio Domingos [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil)

    2008-07-01

    The aim of the present study is to identify and analyze the factors, motivations and criteria being considered in the decision-making processes of the actors belonging to the biodiesel production chain in RS, and confirm or otherwise, the existence of alignment in the decision-making process. Interviews were carried out with the main agents of the links that comprise the biodiesel chains in RS: 11 agricultural co-operatives, 3 biodiesel production plants and a firm that processes and distributes diesel/biodiesel. With regard the decision-making process of the cooperatives, it is centered on the decision to offer, or otherwise, oil-bearing crops for the production of biodiesel. Their decisions emphasize operational and short-term aspects. In contrast, in the firms producing biodiesel, their decision to produce this fuel is associated with addition of one more product to their market portfolio, and is correlated with a long-term view and the search for economic efficiency. In these firms, the benefits of the tax incentives offered by the public policies strongly influence the decision regarding the alternative oil-bearing crops used in the production of biodiesel. In the distributor, it was seen that the decision-making process was guided by long-term strategies. The decision to mix biodiesel with diesel oil being related to the institutional aspect, whatever the legal obligation to mix the fuels may be. In summary, the results show the existence of different characteristics linked to the decision-making process and a significant lack of synchronicity in the aims and motivations of the agents decisions. This state of decisional mis-alignment, associated with the fragilities of public policy, leads to heightened uncertainty regarding the sustainability of the Brazilian biodiesel production program. (author)

  8. Associative foundation of causal learning in rats.

    Science.gov (United States)

    Polack, Cody W; McConnell, Bridget L; Miller, Ralph R

    2013-03-01

    Are humans unique in their ability to interpret exogenous events as causes? We addressed this question by observing the behavior of rats for indications of causal learning. Within an operant motor-sensory preconditioning paradigm, associative surgical techniques revealed that rats attempted to control an outcome (i.e., a potential effect) by manipulating a potential exogenous cause (i.e., an intervention). Rats were able to generate an innocuous auditory stimulus. This stimulus was then paired with an aversive stimulus. The animals subsequently avoided potential generation of the predictive cue, but not if the aversive stimulus was subsequently devalued or the predictive cue was extinguished (Exp. 1). In Experiment 2, we demonstrated that the aversive stimulus we used was in fact aversive, that it was subject to devaluation, that the cue-aversive stimulus pairings did make the cue a conditioned stimulus, and that the cue was subject to extinction. In Experiments 3 and 4, we established that the decrease in leverpressing observed in Experiment 1 was goal-directed instrumental behavior rather than purely a product of Pavlovian conditioning. To the extent that interventions suggest causal reasoning, it appears that causal reasoning can be based on associations between contiguous exogenous events. Thus, contiguity appears capable of establishing causal relationships between exogenous events. Our results challenge the widely held view that causal learning is uniquely human, and suggest that causal learning is explicable in an associative framework. PMID:22562460

  9. Causal factors of acute gastroenteritis in infants and young children.

    Science.gov (United States)

    Zvizdić, Sukrija; Kapić, Elvedina; Hamzić, Sadeta

    2005-02-01

    Respiratory, gastrointestinal and skin diseases represent the most common diseases in infants and young children. Causal factors of these diseases are important infectious agents and causes of pathological conditions in children, but they are also very important for their parents, as well as for people in their close environment. Greater incidence of infections in infants and young children can be explained in different ways. A cause can be insufficient maturity of their immune system, but also their exposure to infections within collective accommodations (cribs, nurseries, pre-school institutions), where they are, at the same time, exposed to a number of unknown agents. Today, a great emphasis is devoted to the ways and kinds of children's nutrition. The problem of relation between infected young organism and infectious agent itself, is also reflected in a long resistance and excretion of microorganisms in their exterior environment. It is well-known that microorganisms resist and excrete much longer in younger organisms, compared to adults, where their resistance and excretion is much shorter or very rare. Actually, adults have already formed protective immunity against particular infectious agents. It doesn't prevent infections in adults, colonization of pathogens, nor eventual development of disease. Established immunity can shorten the time necessary for excretion of microorganisms in their exterior environment and, if disease gets developed, it is of shorter duration and slower progress. PMID:15771601

  10. Blendas de poliamida 6/elastômero: propriedades e influência da adição de agente compatibilizante

    OpenAIRE

    Barra Guilherme M. O.; Roeder Jerusa; Soldi Valdir; Pires Alfredo T. N.; Agnelli José A. M.

    2003-01-01

    Neste trabalho foram estudadas as propriedades micro e macroscópicas de misturas físicas binárias de poliamida 6 [PA6] com copolímero poli(etileno-co-propileno-co-dieno) [EPDM] e em presença de pequenas quantidades de EPDM ou EPM enxertados com anidrido maleico, atuando como agentes compatibilizantes. Os componentes puros (poliamida 6 e EPDM) e as blendas poliméricas em diferentes composições foram analisados por calorimetria diferencial de varredura (DSC) e espectroscopia de infravermelho (F...

  11. Synthesis and preliminary evaluation of N-acylhydrazone compounds as antibacterial and antifungal agents; Sintese e avaliacao preliminar da atividade antibacteriana e antifungica de derivados N-acilidrazonicos

    Energy Technology Data Exchange (ETDEWEB)

    Cachiba, Thomas Haruo; Carvalho, Bruno Demartini; Carvalho, Diogo Teixeira [Universidade Federal de Alfenas, MG (Brazil). Fac. de Ciencias Farmaceuticas. Dept. de Alimentos e Medicamentos; Cusinato, Marina; Prado, Clara Gaviao; Dias, Amanda Latercia Tranches, E-mail: diogo.carvalho@unifal-mg.edu.br [Universidade Federal de Alfenas, MG (Brazil). Inst. de Ciencias Biomedicas

    2012-07-01

    We describe the synthesis and evaluation of N-acylhydrazone compounds bearing different electron-donating groups in one of its aromatic rings, obtained using a four-step synthetic route. IC{sub 50} values against pathogenic fungi and bacteria were determined by serial microdilution. Compounds showed low activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. By contrast, a derivative with a meta-oriented electron-donating group showed significant activity (IC50) against Candida albicans (17 {mu}M), C. krusei (34 {mu}M) and C. tropicalis (17 {mu}M). Results suggest this is a promising lead-compound for synthesis of potent antifungal agents. (author)

  12. Avaliação clínica e morfológica da ação da hidroquinona e do ácido fítico como agentes despigmentantes

    OpenAIRE

    Gardoni, Benilda L. K.; Sato, Mayumi Eliza Otsuka; Pontarolo, Roberto; Noronha, Lucía; Reichert, Adriane; Serafini, Sergio Z.

    2004-01-01

    A eficácia in vivo do creme de ácido fítico 2% (A), foi comparada ao de hidroquinona 4% (B), em estudo comparativo duplo cego, com dezoito voluntários sadios, pele fototipo IV (Fitzpatrick). Na análise macroscópica não se observou alterações na coloração da pele. No ensaio histoquímico subjetivo não houve redução perceptível do pigmento melânico. Observou-se significativa redução do número de melanócitos com a hidroquinona (28,22), superior ao ácido fítico (30,74) e ao controle (3...

  13. Preschoolers prefer to learn causal information

    Directory of Open Access Journals (Sweden)

    Aubry eAlvarez

    2015-02-01

    Full Text Available Young children, in general, appear to have a strong drive to explore the environment in ways that reveal its underlying causal structure. But are they really attuned specifically to casual information in this quest for understanding, or do they show equal interest in other types of non-obvious information about the world? To answer this question, we introduced 20 three-year-old children to two puppets who were anxious to tell the child about a set of novel artifacts and animals. One puppet consistently described causal properties of the items while the other puppet consistently described carefully matched non-causal properties of the same items. After a familiarization period in which children learned which type of information to expect from each informant, children were given the opportunity to choose which they wanted to hear describe each of eight pictured test items. On average, children chose to hear from the informant that provided causal descriptions on 72% of the trials. This preference for causal information has important implications for explaining the role of conceptual information in supporting early learning and may suggest means for maximizing interest and motivation in young children.

  14. Quantum causality in closed timelike curves

    Science.gov (United States)

    Korotaev, S. M.; Kiktenko, E. O.

    2015-08-01

    Although general relativity allows the existence of closed timelike curves (CTCs), self-consistency problems arise (the ‘grandfather paradox’ among others). It is known that quantum mechanical consideration of the matter formally removes all the paradoxes, but the questions about causal structure remain. On the other hand, the idea of postselected CTCs (P-CTC) in quantum teleportation has know been put forward and experimentally implemented. We consider these problems with the aid of quantum causal analysis, where causality is defined without invoking the time relation. It implements the Cramer principle of weak causality, which admits time reversal in entangled states. We analyze Deutsch CTCs (D-CTC) with different kinds of interactions between the chronology-violating and chronology-respecting particles, with refined inferences about mixedness, quantum/classical correlations, entanglement and thermodynamics in the D-CTC. The main result is that time reversal causality can really exist, however, the final quantum state does not place retrospective constraints on the initial state, instead the final state can influence the state inside the D-CTC. This is effectively the implementation of Novikov self-consistency principle. The P-CTC has radically different properties; in particular, if the initial state was pure, the final state is always pure too. Self-consistency is controlled by the initial state-dependent traversability of the P-CTC.

  15. Causality, initial conditions and inflationary magnetogenesis

    CERN Document Server

    Tsagas, Christos G

    2016-01-01

    The post-inflationary evolution of inflation-produced magnetic fields, conventional or not, can change dramatically when two fundamental issues are accounted for. The first is causality, which demands that local physical processes can never affect superhorizon perturbations. The second is the nature of the transition from inflation to reheating and then to the radiation era, which determine the initial conditions at the start of these epochs. Technically, the latter issue can be addressed by appealing to Israel's junction conditions. Causality implies that inflationary magnetic fields dot not freeze into the matter until they have re-entered the causal horizon. The nature of cosmological transitions and the associated initial conditions, on the other hand, determine the large-scale magnetic evolution after inflation. Put together, the two can slow down the adiabatic decay of superhorizon-sized magnetic fields throughout their post-inflationary life and thus lead to considerably stronger residual strengths. Th...

  16. Causal Mediation Analyses for Randomized Trials.

    Science.gov (United States)

    Lynch, Kevin G; Cary, Mark; Gallop, Robert; Ten Have, Thomas R

    2008-01-01

    In the context of randomized intervention trials, we describe causal methods for analyzing how post-randomization factors constitute the process through which randomized baseline interventions act on outcomes. Traditionally, such mediation analyses have been undertaken with great caution, because they assume that the mediating factor is also randomly assigned to individuals in addition to the randomized baseline intervention (i.e., sequential ignorability). Because the mediating factors are typically not randomized, such analyses are unprotected from unmeasured confounders that may lead to biased inference. We review several causal approaches that attempt to reduce such bias without assuming that the mediating factor is randomized. However, these causal approaches require certain interaction assumptions that may be assessed if there is enough treatment heterogeneity with respect to the mediator. We describe available estimation procedures in the context of several examples from the literature and provide resources for software code. PMID:19484136

  17. Bulk viscous cosmology with causal transport theory

    International Nuclear Information System (INIS)

    We consider cosmological scenarios originating from a single imperfect fluid with bulk viscosity and apply Eckart's and both the full and the truncated Müller-Israel-Stewart's theories as descriptions of the non-equilibrium processes. Our principal objective is to investigate if the dynamical properties of Dark Matter and Dark Energy can be described by a single viscous fluid and how such description changes when a causal theory (Müller-Israel-Stewart's, both in its full and truncated forms) is taken into account instead of Eckart's non-causal one. To this purpose, we find numerical solutions for the gravitational potential and compare its behaviour with the corresponding ΛCDM case. Eckart's and the full causal theory seem to be disfavoured, whereas the truncated theory leads to results similar to those of the ΛCDM model for a bulk viscous speed in the interval 10−11 || cb2 ∼−8

  18. The causal meaning of Hamilton's rule.

    Science.gov (United States)

    Okasha, Samir; Martens, Johannes

    2016-03-01

    Hamilton's original derivation of his rule for the spread of an altruistic gene (rb>c) assumed additivity of costs and benefits. Recently, it has been argued that an exact version of the rule holds under non-additive pay-offs, so long as the cost and benefit terms are suitably defined, as partial regression coefficients. However, critics have questioned both the biological significance and the causal meaning of the resulting rule. This paper examines the causal meaning of the generalized Hamilton's rule in a simple model, by computing the effect of a hypothetical experiment to assess the cost of a social action and comparing it to the partial regression definition. The two do not agree. A possible way of salvaging the causal meaning of Hamilton's rule is explored, by appeal to R. A. Fisher's 'average effect of a gene substitution'. PMID:27069669

  19. Causal inheritance in plane wave quotients

    International Nuclear Information System (INIS)

    We investigate the appearance of closed timelike curves in quotients of plane waves along spacelike isometries. First we formulate a necessary and sufficient condition for a quotient of a general spacetime to preserve stable causality. We explicitly show that the plane waves are stably causal; in passing, we observe that some pp-waves are not even distinguishing. We then consider the classification of all quotients of the maximally supersymmetric ten-dimensional plane wave under a spacelike isometry, and show that the quotient will lead to closed timelike curves iff the isometry involves a translation along the u direction. The appearance of these closed timelike curves is thus connected to the special properties of the light cones in plane wave spacetimes. We show that all other quotients preserve stable causality

  20. Causal inheritence in plane wave quotients

    Energy Technology Data Exchange (ETDEWEB)

    Hubeny, Veronika E.; Rangamani, Mukund; Ross, Simon F.

    2003-11-24

    We investigate the appearance of closed timelike curves in quotients of plane waves along spacelike isometries. First we formulate a necessary and sufficient condition for a quotient of a general spacetime to preserve stable causality. We explicitly show that the plane waves are stably causal; in passing, we observe that some pp-waves are not even distinguishing. We then consider the classification of all quotients of the maximally supersymmetric ten-dimensional plane wave under a spacelike isometry, and show that the quotient will lead to closed timelike curves iff the isometry involves a translation along the u direction. The appearance of these closed timelike curves is thus connected to the special properties of the light cones in plane wave spacetimes. We show that all other quotients preserve stable causality.

  1. Normalizing the causality between time series

    Science.gov (United States)

    Liang, X. San

    2015-08-01

    Recently, a rigorous yet concise formula was derived to evaluate information flow, and hence the causality in a quantitative sense, between time series. To assess the importance of a resulting causality, it needs to be normalized. The normalization is achieved through distinguishing a Lyapunov exponent-like, one-dimensional phase-space stretching rate and a noise-to-signal ratio from the rate of information flow in the balance of the marginal entropy evolution of the flow recipient. It is verified with autoregressive models and applied to a real financial analysis problem. An unusually strong one-way causality is identified from IBM (International Business Machines Corporation) to GE (General Electric Company) in their early era, revealing to us an old story, which has almost faded into oblivion, about "Seven Dwarfs" competing with a giant for the mainframe computer market.

  2. Doença da arranhadura do gato por Bartonella quintana em lactente: uma apresentação incomum

    Directory of Open Access Journals (Sweden)

    Azevedo Zina Maria Almeida de

    2000-01-01

    Full Text Available Relato de caso de doença da arranhadura do gato (DAG, em um paciente lactente, com história epidemiológica negativa, descrevendo o rastreamento diagnóstico, a imagem ao ultra-som, a evolução clínica e o prognóstico. B. quintana foi identificada em aspirado de secreção ganglionar pelo método de PCR. B. henselae, embora seja o agente causal habitualmente responsável pela DAG, não foi isolada. Os autores concluem que a pesquisa de B. quintana e B. henselae deve ser incluída na investigação de adenites, principalmente quando a evolução é subaguda, mesmo em lactentes e, ainda que a história epidemiológica seja negativa.

  3. Infecção por Mycobacterium tuberculosis entre agentes comunitários de saúde que atuam no controle da TB Mycobacterium tuberculosis infection among community health workers involved in TB control

    Directory of Open Access Journals (Sweden)

    Patrícia Marques Rodrigues

    2009-04-01

    Full Text Available OBJETIVO: Avaliar a incidência de infecção por Mycobacterium tuberculosis através da prova tuberculínica em agentes comunitários de saúde (ACS que acompanham pacientes em tratamento de TB no município de Cachoeiro de Itapemirim (ES. MÉTODOS: Incluímos 30 ACS que atuam no Programa de Saúde da Família e 30 de seus familiares residentes no mesmo domicílio. Comparamos o resultado do teste tuberculínico de cada ACS e do membro familiar correspondente. RESULTADOS: Entre os 30 ACS, 27 (90,0% eram do sexo feminino, ao passo que entre os 30 familiares, 23 (76,7% eram do sexo feminino (p = 0,299. A idade média do grupo ACS e do grupo dos familiares foi, respectivamente, 36,8 e 39,7 anos. Não houve diferença estatística no nível de escolaridade entre os grupos estudados. Na investigação da exposição ao M. tuberculosis, o mesmo número de indivíduos nos dois grupos afirmou conhecer ou já ter tido algum contato com paciente com TB (17 indivíduos; 56,7%. Houve diferença estatisticamente significativa quanto ao resultado positivo da prova tuberculínica nos dois grupos (26,7% no grupo ACS e 3,3% no grupo de familiares; p = 0,011. CONCLUSÕES: A infecção por M. tuberculosis entre os ACS foi significativamente maior que entre seus familiares, e isso contribui para o debate em torno do risco ocupacional envolvido nas atividades destes profissionais.OBJECTIVE: To evaluate the incidence of Mycobacterium tuberculosis infection, using tuberculin skin test, among community health agents (CHAs monitoring TB patients in the city of Cachoeiro de Itapemirim, Brazil. METHODS: We included 30 CHAs acting in the Family Health Program and 30 of their family members residing in the same household. The tuberculin skin test results of each CHA were compared with those of the corresponding family member. RESULTS: Of the 30 CHAs, 27 (90.0% were female, compared with 23 (76.7% of the 30 family members (p = 0.299. The mean age of the CHA group and of the

  4. Hume’s understanding of causal explanation

    Directory of Open Access Journals (Sweden)

    Stefanović Igor

    2015-01-01

    Full Text Available This article deals with actuality of Hume’s positive thesis about causality, specifically in modern science. According to Dauer, Hume in his Treatise of Human Nature does not deal with scientific theory which allows us, in modern times, to come to the truth, and then necessity. Also, he claims that observation alone, without theory is useless, which is the reason why we need science to predict future events. I intend to show that all three claims are incorrect, and to show an intimate connection of causality and our intuitions.

  5. A causally connected superluminal Warp Drive spacetime

    CERN Document Server

    Loup, F; Waite, D; Halerewicz, E F; Stabno, M; Kuntzman, M; Sims, R

    2002-01-01

    It will be shown that while horizons do not exist for warp drive spacetimes traveling at subluminal velocities horizons begin to develop when a warp drive spacetime reaches luminal velocities. However it will be shown that the control region of a warp drive ship lie within the portion of the warped region that is still causally connected to the ship even at superluminal velocities, therefore allowing a ship to slow to subluminal velocities. Further it is shown that the warped regions which are causally disconnected from a warp ship have no correlation to the ship velocity.

  6. Causal interpretation of stochastic differential equations

    DEFF Research Database (Denmark)

    Sokol, Alexander; Hansen, Niels Richard

    2014-01-01

    We give a causal interpretation of stochastic differential equations (SDEs) by defining the postintervention SDE resulting from an intervention in an SDE. We show that under Lipschitz conditions, the solution to the postintervention SDE is equal to a uniform limit in probability of postintervention...... structural equation models based on the Euler scheme of the original SDE, thus relating our definition to mainstream causal concepts. We prove that when the driving noise in the SDE is a Lévy process, the postintervention distribution is identifiable from the generator of the SDE....

  7. Causal Entropy Bound for a Spacelike Region

    Science.gov (United States)

    Brustein, R.; Veneziano, G.

    2000-06-01

    The identification of a causal-connection scale motivates us to propose a new covariant bound on entropy within a generic spacelike region. This ``causal entropy bound,'' scaling as EV, and thus lying around the geometric mean of Bekenstein's S/ER and holographic S/A bounds, is checked in various ``critical'' situations. In the case of limited gravity, Bekenstein's bound is the strongest while naive holography is the weakest. In the case of strong gravity, our bound and Bousso's holographic bound are stronger than Bekenstein's, while naive holography is too tight, and hence typically wrong.

  8. Efetividade de programa de agentes comunitários na promoção da saúde bucal Efectividad del programa de agentes comunitarios en la promoción de la salud bucal Effectiveness of a community health worker program on oral health promotion

    Directory of Open Access Journals (Sweden)

    Paulo Frazão

    2009-06-01

    Full Text Available OBJETIVO:Avaliar mudanças em conhecimentos, atitudes e acesso/utilização de serviços odontológicos decorrentes de um programa de promoção da saúde bucal com agentes comunitários de saúde. MÉTODOS:Um projeto de capacitação combinando ensino-aprendizagem, apoio e supervisão, foi desenvolvido entre os meses de julho de 2003 a agosto de 2004. As mudanças foram avaliadas por meio de entrevistas estruturadas em que participaram 36 agentes comunitários de saúde e uma amostra de 91 mulheres e mães, representativa de donas de casa com 25 a 39 anos de idade, alfabetizadas e residentes em domicílios de três a seis cômodos no município de Rio Grande da Serra (SP. Foram colhidos dados sobre conhecimentos de saúde-doença bucal, práticas e capacidades auto-referidas em relação ao auto-exame, higiene bucal, número de residentes e de escovas dentais individuais e coletivas em cada domicílio e acesso e uso de serviços odontológicos. Por meio do teste t de Student pareado, foram comparadas as médias dos valores obtidos antes e depois do programa para cada um dos grupos estudados. As respostas foram analisadas adotando-se um nível de significância de 5%. RESULTADOS: Foram observadas diferenças estatisticamente significativas para questões relativas ao conhecimento de saúde bucal entre os agentes e entre as mulheres antes e depois da capacitação (pOBJETIVO: Evaluar cambios en conocimientos, actitudes y acceso/utilización de servicios odontológicos productos de un programa de promoción de la salud bucal con agentes comunitarios de salud. MÉTODOS: Un proyecto de capacitación combinando enseñanza-aprendizaje, apoyo y supervisión, fue desarrollado entre los meses de julio de 2003 a agosto de 2004. Los cambios fueron evaluados por medio de entrevistas estructuradas en las que participaron 36 agentes comunitarios de salud y una muestra representativa de 91 mujeres y madres amas de casa con 25 a 39 años de edad, alfabetizadas

  9. Comparative study of the action of two different types of bleaching agents activated by two different types of irradiation fonts: xenon plasma arc lamp and 960 nm diode laser; Avaliacao da cor e estudo comparativo da acao de dois tipos diferentes de agentes clareadores ativados pelo laser de diodo e lampada xenonio plasmatica, na superficie do esmalte

    Energy Technology Data Exchange (ETDEWEB)

    Walverde, Debora Ayala

    2001-07-01

    This in vitro study compares two different types of tooth bleaching agents stimulated with two different irradiation fonts. These fonts accelerate the action of the bleaching agents upon the enamel surface by heating up the materials. We used the xenon plasma arc lamp and a 960 nm fiber-coupled diode laser to irradiate the two materials containing 35% of hydrogen peroxide (Opus White and Opalescence extra). The color of the teeth was measured with a spectrophotometer using the CIELAB color system that gives the numeric values of L{sup *}a{sup *}b{sup *}. (author)

  10. A Causal Construction of Diffusion Processes

    OpenAIRE

    Banek, Tadeusz

    2010-01-01

    A simple nonlinear integral equation for Ito's map is obtained. Although, it does not include stochastic integrals, it does give causal construction of diffusion processes which can be easily implemented by iteration systems. Applications in financial modelling and extension to fBm are discussed.

  11. Causal dissipative hydrodynamics for heavy ion collisions

    CERN Document Server

    Chaudhuri, A K

    2011-01-01

    We briefly discuss the recent developments in causal dissipative hydrodynamic for relativistic heavy ion collisions. Phenomenological estimate of QGP viscosity over entropy ratio from several experimental data, e.g. STAR's $\\phi$ meson data, centrality dependence of elliptic flow, universal scaling elliptic flow etc. are discussed. QGP viscosity, extracted from hydrodynamical model analysis can have very large systematic uncertainty due to uncertain initial conditions.

  12. Causality and analyticity in quantum fields theory

    International Nuclear Information System (INIS)

    This is a presentation of results on the causal and analytical structure of Green functions and on the collision amplitudes in fields theories, for massive particles of one type, with a positive mass and a zero spin value. (A.B.)

  13. Manipulation and the causal Markov condition

    OpenAIRE

    Hausman, Daniel; Woodward, James

    2004-01-01

    This paper explores the relationship between a manipulability conception of causation and the causal Markov condition (CM). We argue that violations of CM also violate widely shared expectations—implicit in the manipulability conception—having to do with the absence of spontaneous correlations. They also violate expectations concerning the connection between independence or dependence relationships in the presence and absence of interventions.

  14. Escaping Myopia: Teaching Students about Historical Causality

    Science.gov (United States)

    Waring, Scott M.

    2010-01-01

    There are so many aspects to teaching history that are vital to creating well-rounded historical thinkers, but one of the most fundamental and most overlooked elements is the idea of causality. Far too many students do not understand the idea of causation, that there are multiple reasons for why historical events occurred and transpired in the way…

  15. Causality and Teleology in High School Biology.

    Science.gov (United States)

    Tamir, Pinchas

    1985-01-01

    Ability to distinguish between causal (cause-effect) and teleological (means-ends) explanations was measured in 1905 twelfth-grade biology students and found to be dependent on student knowledge. Although the inability to make these distinctions contributes to misconceptions in biology, appropriate instruction can easily remedy the problem. Sample…

  16. Causal and Teleological Explanations in Biology

    Science.gov (United States)

    Yip, Cheng-Wai

    2009-01-01

    A causal explanation in biology focuses on the mechanism by which a biological process is brought about, whereas a teleological explanation considers the end result, in the context of the survival of the organism, as a reason for certain biological processes or structures. There is a tendency among students to offer a teleological explanation…

  17. Comments: Causal Interpretations of Mediation Effects

    Science.gov (United States)

    Jo, Booil; Stuart, Elizabeth A.

    2012-01-01

    The authors thank Dr. Lindsay Page for providing a nice illustration of the use of the principal stratification framework to define causal effects, and a Bayesian model for effect estimation. They hope that her well-written article will help expose education researchers to these concepts and methods, and move the field of mediation analysis in…

  18. Heterogeneous Causal Effects and Sample Selection Bias

    DEFF Research Database (Denmark)

    Breen, Richard; Choi, Seongsoo; Holm, Anders

    2015-01-01

    The role of education in the process of socioeconomic attainment is a topic of long standing interest to sociologists and economists. Recently there has been growing interest not only in estimating the average causal effect of education on outcomes such as earnings, but also in estimating how cau...

  19. Inferring causality from noisy time series data

    DEFF Research Database (Denmark)

    Mønster, Dan; Fusaroli, Riccardo; Tylén, Kristian;

    2016-01-01

    even causality direction in synchronized time-series and in the presence of intermediate coupling. We find that the presence of noise deterministically reduces the level of cross-mapping fidelity, while the convergence rate exhibits higher levels of robustness. Finally, we propose that controlled noise...

  20. Linear Response Laws and Causality in Electrodynamics

    Science.gov (United States)

    Yuffa, Alex J.; Scales, John A.

    2012-01-01

    Linear response laws and causality (the effect cannot precede the cause) are of fundamental importance in physics. In the context of classical electrodynamics, students often have a difficult time grasping these concepts because the physics is obscured by the intermingling of the time and frequency domains. In this paper, we analyse the linear…

  1. Agent engineering

    CERN Document Server

    Liu, Jiming; Zhong, Ning; Wang, Patrick S P

    2001-01-01

    Agent engineering concerns the development of autonomous computational or physical entities capable of perceiving, reasoning, adapting, learning, cooperating and delegating in a dynamic environment. It is one of the most promising areas of research and development in information technology, computer science and engineering. This book addresses some of the key issues in agent engineering: What is meant by "autonomous agents"? How can we build agents with autonomy? What are the desirable capabilities of agents with respect to surviving (they will not die) and living (they will furthermore enjoy

  2. Tolerância a agente curarizante provocada pela administração repetida da droga Tolerance to curarizing drug induced by chronic administration: an experimental study

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Zanini

    1974-03-01

    Full Text Available Baseados em teoria discutível segundo a qual a miastenia grave é provocada pela presença no sangue de substância curarizante liberada pelo timo, tentou-se reproduzir um modelo experimental. Foram utilizados 40 ratos, criados nas mesmas condições, nascidos no mesmo dia, pesando ao redor de 350 g e divididos em 4 grupos: o Grupo I não foi manuseado; no Grupo II foi injetada solução fisiológica, 1 ml i.p. durante 6 semanas; no Grupo III foi injetada a dimetil tubocurarina (DMT 2,8 mcg/kg i.p., durante o mesmo tempo; no Grupo IV 14 mcg/kg da mesma droga foram injetados i.p. Uma semana após a última injeção i.p. os ratos, anestesiados, foram preparados para registro neuromuscular. O nervo ciático foi estimulado nas freqüências de 0,33 pulsos/seg, 70 pulsos/seg (séries de 10 pulsos a intervalos de 3 seg, 70 pulsos/seg (mantidos por 15 seg e novamente 0,33 pulsos/seg logo após a tetanização. A dose curarizante de DMT foi determinada por uma "terceira parte cega" quando 80% do bloqueio era alcançado. Quando apenas 10 estímulos em alta freqüência foram aplicados ao nervo, foi observada diferença significativa (pThe trial is a temptative experimental model of myasthenia gravis based on a doubtful theory whereby this disease is atributed to circulating curare in blood. Forty rats kept under the same conditions, bom on the same day and weighing around 350 g entered the trial, divided in four groups. Group I was not handled, Group II was injected with saline, 1 ml i.p. Group III was submitted to dimethyl tubocurarine iodide (DMT 2,8 mcg/kg i.p. and Group IV received 14 mcg/kg, all solutions being administered daily for a six-week period. One week after the last rats were anesthetized and prepared for cyatic-gastrocnemius neuro-muscular recording. Monopolar pulses were given at frequencies of 0.33 p/sec, 70 p/sec, (trains of 10 pulses at 3 sec intervals, 70 p/sec (kept for 15 sec and again 0.33 p/sec right after tetanus. Curarizing

  3. Equivalência de dulçor e poder edulcorante de edulcorantes em função da temperatura de consumo em bebidas preparadas com chá-mate em pó solúvel Equi-sweetness and sweetening power of different sweetening agents in differents temperatures of consumption of tea drink in soluble power

    OpenAIRE

    Juliana Maria Porto Cardoso; Juliana Rosa Battochio; Helena Maria André Bolini Cardello

    2004-01-01

    No presente estudo foi verificado o efeito da temperatura de consumo na equivalência de doçura e no poder edulcorante de diferentes agentes adoçantes em bebida de chá-mate em pó solúvel. Foram avaliados: aspartame, sucralose, mistura ciclamato/sacarina 2:1, Stevia e acessulfame-K, tendo como referência a sacarose. Todos os estudos foram realizados a 6±2ºC e a 45±2ºC. Primeiramente foi determinada a doçura ideal, utillizando-se escala do ideal com 30 provadores consumidores da be...

  4. O papel dos antipsicóticos atípicos no tratamento do transtorno bipolar: revisão da literatura The role of atypical antipsychotic agents in the treatment of bipolar disorder: a literature review

    Directory of Open Access Journals (Sweden)

    Acioly LT Lacerda

    2002-03-01

    Full Text Available Estudos recentes têm demonstrado que a eficácia do lítio é significativamente inferior à descrita pelos primeiros trabalhos, embora ainda seja a medicação de referência no tratamento do transtorno afetivo bipolar. Apesar de um perfil de segurança desfavorável, os antipsicóticos clássicos sempre apresentaram um papel importante no tratamento desse transtorno psiquiátrico, especialmente como coadjuvante em sua fase maníaca aguda. Os autores, utilizando informação obtida no Medline, fizeram uma revisão acerca do papel dos antipsicóticos atípicos no tratamento dos pacientes bipolares. Baseado nos dados da literatura, a olanzapina mostrou-se bastante eficaz no manejo da mania aguda, quando uma média de 63,5% dos pacientes apresentaram melhora significativa em estudos duplo-cego controlados, apresentando ganho de peso como único efeito colateral relevante. A clozapina e, mais ainda, a risperidona apresentaram dados menos consistentes, grande parte em função de deficiências metodológicas dos poucos estudos conduzidos até o presente estudo. Os dados preliminares relativos à eficácia desse grupo farmacológico nos quadros refratários e nos sintomas depressivos são promissores, mas ainda não definitivos. Em relação a seus efeitos potenciais como estabilizadores do humor, não existem evidências conclusivas oriundas de estudos controlados, mas há interesse considerável para realização de investigações em pacientes bipolares tratados com antipsicóticos atípicos por períodos de tempo mais prolongados. Pesquisas futuras poderão tornar mais claras essas possíveis características terapêuticas.Even though lithium is still the choice drug in the treatment of bipolar disorder, recent studies have shown that it has a significant lower efficacy than previously described in earlier studies. Despite its adverse side effects, typical antipsychotic agents have often had a prominent role in the treatment of this psychiatric

  5. The causal link between energy and output growth: Evidence from Markov switching Granger causality

    International Nuclear Information System (INIS)

    In this paper we empirically investigate the causal link between energy consumption and economic growth employing a Markov switching Granger causality analysis. We carry out our investigation using annual U.S. real GDP, total final energy consumption and total primary energy consumption data which cover the period between 1968 and 2010. We find that there are significant changes in the causal relation between energy consumption and economic growth over the sample period under investigation. Our results show that total final energy consumption and total primary energy consumption have significant predictive content for real economic activity in the U.S. economy. Furthermore, the causality running from energy consumption to output growth seems to be strongly apparent particularly during the periods of economic downturn and energy crisis. We also document that output growth has predictive power in explaining total energy consumption. Furthermore, the power of output growth in predicting total energy consumption is found to diminish after the mid of 1980s. - Highlights: • Total energy consumption has predictive content for real economic activity. • The causality from energy to output growth is apparent in the periods of recession. • The causality from energy to output growth is strong in the periods of energy crisis. • Output growth has predictive power in explaining total energy consumption. • The power of output growth in explaining energy diminishes after the mid of 1980s

  6. Agentes comunitários de saúde da zona leste do município de São Paulo: um olhar para seu estado nutricional e consumo alimentar - doi:10.5020/18061230.2008.p3

    Directory of Open Access Journals (Sweden)

    Alexanndra Corrêa de Freitas

    2012-01-01

    Full Text Available Objetivo: Caracterizar o perfil sócio-demográfico, o estado nutricional, a presença de doenças crônicas não-transmissíveis e o consumo alimentar de agentes comunitários de saúde (ACS pertencentes a cinco Unidades de Saúde da Família da Zona Leste do Município de São Paulo. Métodos: Tratou-se de um estudo quantitativo, descritivo e exploratório desenvolvido com 88 indivíduos. Coletaram-se dados sobre a situação sócio-demográfica, dados antropométricos(peso, estatura e circunferência da cintura, informações sobre presença de doenças crônicas não-transmissíveis e de consumo alimentar. Resultados: Os participantes dessa pesquisa eram predominantemente do sexo feminino 83 (94,3%, com idade variável entre 20 e 55 anos. A maioria era natural da região Sudeste 72 (81,2%, possuía ensino médio concluído 71 (80,7% e tinha renda familiar entre 2 e 5 salários mínimos 62 (70,4%. A avaliação antropométrica revelou que 46 (52,3% estavam eutróficos, 41 (46,6% com excesso de peso e 41 (46,6% apresentavam risco elevado ou muito elevado para doenças cardiovasculares, apesar de 77 (87,5% não terem referido qualquer doença crônica não-transmissível. Quanto ao consumo alimentar, encontrou-se consumo diário de arroz, feijão, pão e margarina ou manteiga e baixo consumo de leite e derivados, frutas, verduras e legumes. As carnes bovina e de frango eram as mais consumidas. O café apareceu como bebida de maior consumo diário, seguido do suco artificial. As frituras e doces eram consumidos semanalmente por 34,9% e 53,4% dos ACS, respectivamente. Conclusão: O excesso de peso e a obesidade abdominal foram os principais acometimentos à saúde dos ACS, tendo, ambos, estreita relação com suas práticas alimentares inadequadas; as quais também estavam relacionadas às suas características sócio-demográficas. NCT00682604.

  7. Identification, Inference and Sensitivity Analysis for Causal Mediation Effects

    OpenAIRE

    Imai, Kosuke; Keele, Luke; Yamamoto, Teppei

    2010-01-01

    Causal mediation analysis is routinely conducted by applied researchers in a variety of disciplines. The goal of such an analysis is to investigate alternative causal mechanisms by examining the roles of intermediate variables that lie in the causal paths between the treatment and outcome variables. In this paper we first prove that under a particular version of sequential ignorability assumption, the average causal mediation effect (ACME) is nonparametrically identified. We compare our ident...

  8. Institutional Investors and Stock Market Development: A Causality Study

    OpenAIRE

    Guler Aras; Alovsat Muslumov

    2008-01-01

    This article examines causality relationships between institutional investors and stock market development based on the panel data compiled from 23 OECD countries for the years 1982 through 2000. In order to test causality relationship, Sims’ causality test based on Granger definition of causality was used in our study. Our empirical results provide evidence that there are statistically significant positive relationship between institutional investors and stock market development. The develop...

  9. Trimmed Granger causality between two groups of time series

    OpenAIRE

    Hung, Ying-Chao; Tseng, Neng-Fang; Balakrishnan, Narayanaswamy

    2014-01-01

    The identification of causal effects between two groups of time series has been an important topic in a wide range of applications such as economics, engineering, medicine, neuroscience, and biology. In this paper, a simplified causal relationship (called trimmed Granger causality) based on the context of Granger causality and vector autoregressive (VAR) model is introduced. The idea is to characterize a subset of “important variables” for both groups of time series so that the underlying cau...

  10. A Bayesian Theory of Sequential Causal Learning and Abstract Transfer

    Science.gov (United States)

    Lu, Hongjing; Rojas, Randall R.; Beckers, Tom; Yuille, Alan L.

    2016-01-01

    Two key research issues in the field of causal learning are how people acquire causal knowledge when observing data that are presented sequentially, and the level of abstraction at which learning takes place. Does sequential causal learning solely involve the acquisition of specific cause-effect links, or do learners also acquire knowledge about…

  11. Causality and Nonlocality as Axioms for Quantum Mechanics

    OpenAIRE

    Popescu, Sandu; Rohrlich, Daniel

    1997-01-01

    Quantum mechanics permits nonlocality - both nonlocal correlations and nonlocal equations of motion - while respecting relativistic causality. Is quantum mechanics the unique theory that reconciles nonlocality and causality? We consider two models, going beyond quantum mechanics, of nonlocality: "superquantum" correlations, and nonlocal "jamming" of correlations. These models are consistent with some definitions of nonlocality and causality.

  12. Mind and Meaning: Piaget and Vygotsky on Causal Explanation.

    Science.gov (United States)

    Beilin, Harry

    1996-01-01

    Piaget's theory has been characterized as descriptive and not explanatory, not qualifying as causal explanation. Piaget was consistent in showing how his theory was both explanatory and causal. Vygotsky also endorsed causal-genetic explanation but, on the basis of knowledge of only Piaget's earliest works, he claimed that Piaget's theory was not…

  13. Sentencing goals, causal attributions, ideology, and personality.

    Science.gov (United States)

    Carroll, J S; Perkowitz, W T; Lurigio, A J; Weaver, F M

    1987-01-01

    Disparity in sentencing of criminals has been related to a variety of individual difference variables. We propose a framework establishing resonances or coherent patterns among sentencing goals, causal attributions, ideology, and personality. Two studies are described, one with law and criminology students, the other with probation officers. Relations among the different types of variables reveal two resonances among both students and officers. One comprises various conservative and moralistic elements: a tough, punitive stance toward crime; belief in individual causality for crime; high scores on authoritarianism, dogmatism, and internal locus of control; lower moral stage; and political conservatism. The second comprises various liberal elements: rehabilitation, belief in economic and other external determinants of crime, higher moral stage, and belief in the powers and responsibilities of government to correct social problems. Implications of these results are discussed for individual differences in sentencing, attribution theory, and attempts to reduce disparity. PMID:3820064

  14. An insider's guide to quantum causal histories

    International Nuclear Information System (INIS)

    A review is given of recent work aimed at constructing a quantum theory of cosmology in which all observables refer to information measurable by observers inside the universe. At the classical level the algebra of observables should be modified to take into account the fact that observers can only give truth values to observables that have to do with their backwards light cone. The resulting algebra is a Heyting rather than a Boolean algebra. The complement is non-trivial and contains information about horizons and topology change. Representation of such observables quantum mechanically requires a many-Hilbert space formalism, in which different observers make measurements in different Hilbert spaces. I describe such a formalism, called 'quantum causal histories'; examples include causally evolving spin networks and quantum computers

  15. Consistence beats causality in recommender systems

    CERN Document Server

    Zhu, Xuzhen; Hu, Zheng; Zhang, Ping; Zhou, Tao

    2015-01-01

    The explosive growth of information challenges people's capability in finding out items fitting to their own interests. Recommender systems provide an efficient solution by automatically push possibly relevant items to users according to their past preferences. Recommendation algorithms usually embody the causality from what having been collected to what should be recommended. In this article, we argue that in many cases, a user's interests are stable, and thus the previous and future preferences are highly consistent. The temporal order of collections then does not necessarily imply a causality relationship. We further propose a consistence-based algorithm that outperforms the state-of-the-art recommendation algorithms in disparate real data sets, including \\textit{Netflix}, \\textit{MovieLens}, \\textit{Amazon} and \\textit{Rate Your Music}.

  16. A New Spin on Causality Constraints

    CERN Document Server

    Hartman, Thomas; Kundu, Sandipan

    2016-01-01

    Causality in a shockwave state is related to the analytic properties of a four-point correlation function. Extending recent results for scalar probes, we show that this constrains the couplings of the stress tensor to light spinning operators in conformal field theory, and interpret these constraints in terms of the interaction with null energy. For spin-1 and spin-2 conserved currents in four dimensions, the resulting inequalities are a subset of the Hofman-Maldacena conditions for positive energy deposition. It is well known that energy conditions in holographic theories are related to causality on the gravity side; our results make a connection on the CFT side, and extend it to non-holographic theories.

  17. Normalizing the causality between time series

    CERN Document Server

    Liang, X San

    2015-01-01

    Recently, a rigorous yet concise formula has been derived to evaluate the information flow, and hence the causality in a quantitative sense, between time series. To assess the importance of a resulting causality, it needs to be normalized. The normalization is achieved through distinguishing three types of fundamental mechanisms that govern the marginal entropy change of the flow recipient. A normalized or relative flow measures its importance relative to other mechanisms. In analyzing realistic series, both absolute and relative information flows need to be taken into account, since the normalizers for a pair of reverse flows belong to two different entropy balances; it is quite normal that two identical flows may differ a lot in relative importance in their respective balances. We have reproduced these results with several autoregressive models. We have also shown applications to a climate change problem and a financial analysis problem. For the former, reconfirmed is the role of the Indian Ocean Dipole as ...

  18. Closed timelike curves and causality violation

    CERN Document Server

    Lobo, Francisco S N

    2010-01-01

    The conceptual definition and understanding of time, both quantitatively and qualitatively is of the utmost difficulty and importance. As time is incorporated into the proper structure of the fabric of spacetime, it is interesting to note that General Relativity is contaminated with non-trivial geometries which generate closed timelike curves. A closed timelike curve (CTC) allows time travel, in the sense that an observer that travels on a trajectory in spacetime along this curve, may return to an event before his departure. This fact apparently violates causality, therefore time travel and it's associated paradoxes have to be treated with great caution. The paradoxes fall into two broad groups, namely the consistency paradoxes and the causal loops. A great variety of solutions to the Einstein field equations containing CTCs exist and it seems that two particularly notorious features stand out. Solutions with a tipping over of the light cones due to a rotation about a cylindrically symmetric axis and solution...

  19. An insider's guide to quantum causal histories

    CERN Document Server

    Markopoulou, F

    2000-01-01

    A review is given of recent work aimed at constructing a quantum theory of cosmology in which all observables refer to information measurable by observers inside the universe. At the classical level the algebra of observables should be modified to take into account the fact that observers can only give truth values to observables that have to do with their backwards light cone. The resulting algebra is a Heyting rather than a Boolean algebra. The complement is non-trivial and contains information about horizons and topology change. Representation of such observables quantum mechanically requires a many-Hilbert space formalism, in which different observers make measurements in different Hilbert spaces. I describe such a formalism, called "quantum causal histories"; examples include causally evolving spin networks and quantum computers.

  20. Granger-Causality Maps of Diffusion Processes

    Czech Academy of Sciences Publication Activity Database

    Wahl, B.; Feudel, U.; Hlinka, Jaroslav; Wächter, M.; Peinke, J.; Freund, J.A.

    2016-01-01

    Roč. 93, č. 2 (2016), 022213/1-022213/9. ISSN 1539-3755 R&D Projects: GA ČR GA13-23940S; GA MZd(CZ) NV15-29835A Institutional support: RVO:67985807 Keywords : Granger causality * stochastic process * diffusion process * nonlinear dynamical systems Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 2.288, year: 2014

  1. Waves and causality in higher dimensions

    CERN Document Server

    Wesson, Paul S

    2015-01-01

    We give a new, wave-like solution of the field equations of five-dimensional relativity. In ordinary three-dimensional space, the waves resemble de Broglie or matter waves, whose puzzling behaviour can be better understood in terms of one or more extra dimensions. Causality is appropriately defined by a null higher-dimensional interval. It may be possible to test the properties of these waves in the laboratory.

  2. Information causality as a physical principle.

    Science.gov (United States)

    Pawłowski, Marcin; Paterek, Tomasz; Kaszlikowski, Dagomir; Scarani, Valerio; Winter, Andreas; Zukowski, Marek

    2009-10-22

    Quantum physics has remarkable distinguishing characteristics. For example, it gives only probabilistic predictions (non-determinism) and does not allow copying of unknown states (no-cloning). Quantum correlations may be stronger than any classical ones, but information cannot be transmitted faster than light (no-signalling). However, these features do not uniquely define quantum physics. A broad class of theories exist that share such traits and allow even stronger (than quantum) correlations. Here we introduce the principle of 'information causality' and show that it is respected by classical and quantum physics but violated by all no-signalling theories with stronger than (the strongest) quantum correlations. The principle relates to the amount of information that an observer (Bob) can gain about a data set belonging to another observer (Alice), the contents of which are completely unknown to him. Using all his local resources (which may be correlated with her resources) and allowing classical communication from her, the amount of information that Bob can recover is bounded by the information volume (m) of the communication. Namely, if Alice communicates m bits to Bob, the total information obtainable by Bob cannot be greater than m. For m = 0, information causality reduces to the standard no-signalling principle. However, no-signalling theories with maximally strong correlations would allow Bob access to all the data in any m-bit subset of the whole data set held by Alice. If only one bit is sent by Alice (m = 1), this is tantamount to Bob's being able to access the value of any single bit of Alice's data (but not all of them). Information causality may therefore help to distinguish physical theories from non-physical ones. We suggest that information causality-a generalization of the no-signalling condition-might be one of the foundational properties of nature. PMID:19847260

  3. Causal Mediation Analyses for Randomized Trials

    OpenAIRE

    Lynch, Kevin G.; Cary, Mark; Gallop, Robert; Ten Have, Thomas R.

    2008-01-01

    In the context of randomized intervention trials, we describe causal methods for analyzing how post-randomization factors constitute the process through which randomized baseline interventions act on outcomes. Traditionally, such mediation analyses have been undertaken with great caution, because they assume that the mediating factor is also randomly assigned to individuals in addition to the randomized baseline intervention (i.e., sequential ignorability). Because the mediating factors are t...

  4. Isocausal spacetimes may have different causal boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Flores, J L; Herrera, J [Departamento de Algebra, Geometria y Topologia, Facultad de Ciencias, Universidad de Malaga, Campus Teatinos, 29071 Malaga (Spain); Sanchez, M, E-mail: floresj@agt.cie.uma.es, E-mail: jherrera@uma.es, E-mail: sanchezm@ugr.es [Departamento de Geometria y Topologia, Facultad de Ciencias, Universidad de Granada, Avenida Fuentenueva s/n, 18071 Granada (Spain)

    2011-09-07

    We construct an example which shows that two isocausal spacetimes, in the sense introduced recently in GarcIa-Parrado and Senovilla (2003 Class. Quantum Grav. 20 625-64), may have c-boundaries which are not equal (more precisely, not equivalent, as no bijection between the completions can preserve all the binary relations induced by causality). This example also suggests that isocausality can be useful for the understanding and computation of the c-boundary.

  5. Representation and reasoning: a causal model approach

    OpenAIRE

    Nikolic, M.

    2014-01-01

    How do we represent our world and how do we use these representations to reason about it? The three studies reported in this thesis explored different aspects of the answer to this question. Even though these investigations offered diverse angles, they all originated from the same psychological theory of representation and reasoning. This is the idea that people represent the world and reason about it by constructing dynamic qualitative causal networks. The first study investigated how mock j...

  6. Reconstructing Causal Biological Networks through Active Learning

    OpenAIRE

    Cho, Hyunghoon; Berger, Bonnie; Peng, Jian

    2016-01-01

    Reverse-engineering of biological networks is a central problem in systems biology. The use of intervention data, such as gene knockouts or knockdowns, is typically used for teasing apart causal relationships among genes. Under time or resource constraints, one needs to carefully choose which intervention experiments to carry out. Previous approaches for selecting most informative interventions have largely been focused on discrete Bayesian networks. However, continuous Bayesian networks are ...

  7. A causally connected superluminal Warp Drive spacetime

    OpenAIRE

    Loup, F.; Held, R.; Waite, D; Halerewicz, Jr., E.; Stabno, M.; Kuntzman, M.; Sims, R.

    2002-01-01

    It will be shown that while horizons do not exist for warp drive spacetimes traveling at subluminal velocities horizons begin to develop when a warp drive spacetime reaches luminal velocities. However it will be shown that the control region of a warp drive ship lie within the portion of the warped region that is still causally connected to the ship even at superluminal velocities, therefore allowing a ship to slow to subluminal velocities. Further it is shown that the warped regions which ar...

  8. Extending Temporal Causal Graph For Diagnosis Problems

    OpenAIRE

    Belouaer, Lamia; Bouzid, Maroua; Mouhoub, Malek

    2009-01-01

    Poster International audience Abductive diagnosis (Brusoni et al. 1998) consists in finding explanations for given observations by using rules of inference based on the causal dependences of the system. Time is important for abductive diagnosis (Hamscher and Davis 1984), (Hamscher, Console, and Kleer 1992). There are few works in litterature handling temporal diagnosis (Kautz 1999). They differ in the expressiveness of the temporal knowledge. We propose a new approach for Temporal Diagn...

  9. Imposing causality on a matrix model

    International Nuclear Information System (INIS)

    We introduce a new matrix model that describes Causal Dynamical Triangulations (CDT) in two dimensions. In order to do so, we introduce a new, simpler definition of 2D CDT and show it to be equivalent to the old one. The model makes use of ideas from dually weighted matrix models, combined with multi-matrix models, and can be studied by the method of character expansion.

  10. Relativistic causality and position space renormalization

    CERN Document Server

    Todorov, Ivan

    2016-01-01

    We survey the causal position space renormalization with a special attention to the role of Raymond Stora in the development of the subject. Renormalization is effected by subtracting pole terms in analytically regularized amplitudes. Residues are identified with periods whose relation to recent development in number theory is emphasized. We demonstrate the possibility of integration over internal vertices in the case of a (massless) conformal theory and display the dilation and the conformal anomaly.

  11. Extracting causal relationships from Chinese written text

    OpenAIRE

    Liu, X; Hoede, C.

    2002-01-01

    Expert systems form one of the most important research areas in Artificial Intelligence. The main parts in expert systems are knowledge bases and inference engines. In the knowledge bases the main knowledge is knowledge in the form of ``IF-THEN" statements. In knowledge graphs, a new form of knowledge representation, the ``IF-THEN" statements are tied up with causal operators (CAU-relations). In this paper, we picked out some Chinese operators with ``CAU" meaning, and investigated these opera...

  12. Causality and the semantics of provenance

    OpenAIRE

    James Cheney

    2010-01-01

    Provenance, or information about the sources, derivation, custody or history of data, has been studied recently in a number of contexts, including databases, scientific workflows and the Semantic Web. Many provenance mechanisms have been developed, motivated by informal notions such as influence, dependence, explanation and causality. However, there has been little study of whether these mechanisms formally satisfy appropriate policies or even how to formalize relevant motivating concepts suc...

  13. Ten simple rules for dynamic causal modeling

    OpenAIRE

    Stephan, K E; Penny, W.D.; Moran, R. J.; den Ouden, H.E.M.; Daunizeau, J.; Friston, K J

    2010-01-01

    Dynamic causal modeling (DCM) is a generic Bayesian framework for inferring hidden neuronal states from measurements of brain activity. It provides posterior estimates of neurobiologically interpretable quantities such as the effective strength of synaptic connections among neuronal populations and their context-dependent modulation. DCM is increasingly used in the analysis of a wide range of neuroimaging and electrophysiological data. Given the relative complexity of DCM, compared to convent...

  14. Causality detection and turbulence in fusion plasmas

    OpenAIRE

    Van Milligen, B Ph; Birkenmeier, G.; Ramisch, M.; Estrada, T.; Hidalgo, C.; A. Alonso

    2013-01-01

    This work explores the potential of an information-theoretical causality detection method for unraveling the relation between fluctuating variables in complex nonlinear systems. The method is tested on some simple though nonlinear models, and guidelines for the choice of analysis parameters are established. Then, measurements from magnetically confined fusion plasmas are analyzed. The selected data bear relevance to the all-important spontaneous confinement transitions often observed in fusio...

  15. Cirurgia conservadora da endocardite bacteriana aguda da valva tricúspide Conservative operation for bacterial endocardites of the tricuspide valve

    Directory of Open Access Journals (Sweden)

    Iseu Affonso da Costa

    1988-08-01

    Full Text Available É relatado o caso de 1 paciente que apresentou endocardite aguda da valva tricúspide pós-aborto, cujo agente causal era o S. aureus. Como não houvesse resposta favorável ao tratamento antibiótico (gentamicina, vancomicina e oxacilina, optou-se pela intervenção, vinte dias após a internação. Foi praticada excisão de uma vegetação única e do tecido valvar adjacente, na comissura ântero-posterior e plicatura anular. O resultado foi favorável, com cura clínica. O exame ecocardiográfico confirmou a presença da vegetação no pré-operatório e o funcionamento conservado da valva, após a plastia. O tratamento cirúrgico, com retirada do tecido infectado e preservação da valva constitui uma alternativa aplicável a certos casos de endocardite aguda das valvas atrioventriculares.One case of acute bacterial endocarditis of the tricuspid valve caused by S. aureus and following a septic abortion is presented. Surgical treatment was indicated after failure of antibiotics. Operation consisted of excision of a large vegetation adherent to the anterior and posterior cusps at the commisure and of the affected valvar tissue. Annular plicature at the segment corresponding to the posterior cuspid was employed to maintain competence. Clinical result was very satisfactory with resolution of sepsis. Dopplerecocardiography revealed the presence of the vegetation before the operation and showed a small regurgitation after valvoplasty. Conservative operation upon the atrioventricular valves must be kept in mind as an alternative in the treatment of acute bacterial endocarditis.

  16. Causal beliefs about depression in different cultural groups – What do cognitive psychological theories of causal learning and reasoning predict?

    OpenAIRE

    York eHagmayer; Neele eEngelmann

    2014-01-01

    Cognitive psychological research focusses on causal learning and reasoning while cognitive anthropological and social science research tend to focus on systems of beliefs. Our aim was to explore how these two types of research can inform each other. Cognitive psychological theories (causal model theory and causal Bayes nets) were used to derive predictions for systems of causal beliefs. These predictions were then applied to lay theories of depression as a specific test case. A systematic...

  17. Causal beliefs about depression in different cultural groups—what do cognitive psychological theories of causal learning and reasoning predict?

    OpenAIRE

    Hagmayer, York; Engelmann, Neele

    2014-01-01

    Cognitive psychological research focuses on causal learning and reasoning while cognitive anthropological and social science research tend to focus on systems of beliefs. Our aim was to explore how these two types of research can inform each other. Cognitive psychological theories (causal model theory and causal Bayes nets) were used to derive predictions for systems of causal beliefs. These predictions were then applied to lay theories of depression as a specific test case. A systematic lite...

  18. Causality, initial conditions, and inflationary magnetogenesis

    Science.gov (United States)

    Tsagas, Christos G.

    2016-05-01

    The post-inflationary evolution of inflation-produced magnetic fields, conventional or not, can change dramatically when two fundamental issues are accounted for. The first is causality, which demands that local physical processes can never affect superhorizon perturbations. The second is the nature of the transition from inflation to reheating and then to the radiation era, which determine the initial conditions at the start of these epochs. Causality implies that inflationary magnetic fields do not freeze into the matter until they have re-entered the causal horizon. The nature of the cosmological transitions and the associated initial conditions, on the other hand, determine the large-scale magnetic evolution after inflation. Put together, the two can slow down the adiabatic magnetic decay on superhorizon scales throughout the Universe's post-inflationary evolution and thus lead to considerably stronger residual magnetic fields. This is "good news" for both the conventional and the nonconventional scenarios of cosmic magnetogenesis. Mechanisms operating outside standard electromagnetism, in particular, do not need to enhance their fields too much during inflation in order to produce seeds that can feed the galactic dynamo today. In fact, even conventionally produced inflationary magnetic fields might be able to sustain the dynamo.

  19. A causal dispositional account of fitness.

    Science.gov (United States)

    Triviño, Vanessa; Nuño de la Rosa, Laura

    2016-09-01

    The notion of fitness is usually equated to reproductive success. However, this actualist approach presents some difficulties, mainly the explanatory circularity problem, which have lead philosophers of biology to offer alternative definitions in which fitness and reproductive success are distinguished. In this paper, we argue  that none of these alternatives is satisfactory and, inspired by Mumford and Anjum's dispositional theory of causation, we offer a definition of fitness as a causal dispositional property. We argue that, under this framework, the distinctiveness that biologists usually attribute to fitness-namely, the fact that fitness is something different from both the physical traits of an organism and the number of offspring it leaves-can be explained, and the main problems associated with the concept of fitness can be solved. Firstly, we introduce Mumford and Anjum's dispositional theory of causation and present our definition of fitness as a causal disposition. We explain in detail each of the elements involved in our definition, namely: the relationship between fitness and the functional dispositions that compose it, the emergent character of fitness, and the context-sensitivity of fitness. Finally, we explain how fitness and realized fitness, as well as expected and realized fitness are distinguished in our approach to fitness as a causal disposition. PMID:27338570

  20. Bayesian Discovery of Linear Acyclic Causal Models

    CERN Document Server

    Hoyer, Patrik O

    2012-01-01

    Methods for automated discovery of causal relationships from non-interventional data have received much attention recently. A widely used and well understood model family is given by linear acyclic causal models (recursive structural equation models). For Gaussian data both constraint-based methods (Spirtes et al., 1993; Pearl, 2000) (which output a single equivalence class) and Bayesian score-based methods (Geiger and Heckerman, 1994) (which assign relative scores to the equivalence classes) are available. On the contrary, all current methods able to utilize non-Gaussianity in the data (Shimizu et al., 2006; Hoyer et al., 2008) always return only a single graph or a single equivalence class, and so are fundamentally unable to express the degree of certainty attached to that output. In this paper we develop a Bayesian score-based approach able to take advantage of non-Gaussianity when estimating linear acyclic causal models, and we empirically demonstrate that, at least on very modest size networks, its accur...

  1. Reliability of the Granger causality inference

    International Nuclear Information System (INIS)

    How to characterize information flows in physical, biological, and social systems remains a major theoretical challenge. Granger causality (GC) analysis has been widely used to investigate information flow through causal interactions. We address one of the central questions in GC analysis, that is, the reliability of the GC evaluation and its implications for the causal structures extracted by this analysis. Our work reveals that the manner in which a continuous dynamical process is projected or coarse-grained to a discrete process has a profound impact on the reliability of the GC inference, and different sampling may potentially yield completely opposite inferences. This inference hazard is present for both linear and nonlinear processes. We emphasize that there is a hazard of reaching incorrect conclusions about network topologies, even including statistical (such as small-world or scale-free) properties of the networks, when GC analysis is blindly applied to infer the network topology. We demonstrate this using a small-world network for which a drastic loss of small-world attributes occurs in the reconstructed network using the standard GC approach. We further show how to resolve the paradox that the GC analysis seemingly becomes less reliable when more information is incorporated using finer and finer sampling. Finally, we present strategies to overcome these inference artifacts in order to obtain a reliable GC result

  2. Cohomology Methods in Causal Perturbation Theory

    International Nuclear Information System (INIS)

    Various problems in perturbation theory of (quantum) gauge models can be rephrased in the language of cohomology theory. This was already noticed in the functional formulation of perturbative gauge theories. Causal perturbation theory is a fully quantum approach: is works only with the chronological products which are defined as operator-valued distributions in the Fock space of the model. The use of causal perturbation theory leads to similar cohomology problems; the main difference with respect to the functional methods comes from the fact that the gauge transformation of the causal approach is, essentially, the linear part of the non-linear BRST transformation.Using these methods it is possible to give a nice determination of the interaction Lagrangians for gauge models (Yang-Mills and gravitation in the linear approximation); one obtains with this method the unicity of the interaction Lagrangian up to trivial terms. The case of quantum gravity is highly non-trivial and can be generalized with this method to the massive graviton case. Going to higher orders of perturbation theory one finds quantum anomalies. Again the cohomological methods can be used to determine the generic form of these anomalies. Finally, one can investigate the arbitrariness of the chronological products in higher orders and reduce this problem to cohomology methods also.

  3. Avaliação do método de disco-difusão para determinação da eficácia da terbinafina in vitro em agentes de micoses superficiais e subcutâneas Evaluation of the disk-diffusion method to determine the in vitro efficacy of terbinafine against subcutaneous and superficial mycoses agents

    OpenAIRE

    Hilda Conceição Diogo; Márcia Melhem; Aldo Sarpieri; Mario Cezar Pires

    2010-01-01

    FUNDAMENTOS: As micoses superficiais e subcutâneas têm alta prevalência e, muitas vezes, caráter crônico, necessitando tratamentos tópicos e/ou sistêmicos com antifúngicos. As drogas de escolha são azóis e alilaminas (terbinafina). É necessário avaliar a eficácia das drogas para tratamento em humanos e em animais. Estudos para avaliar in vitro a ação dos antimicóticos são raros, especialmente, contra fungos filamentosos. OBJETIVO: Avaliar a eficácia in vitro da terbinafina pelo método de disc...

  4. Multivariate Granger Causality Analysis of Acupuncture Effects in Mild Cognitive Impairment Patients: An fMRI Study

    Directory of Open Access Journals (Sweden)

    Shangjie Chen

    2013-01-01

    Full Text Available Evidence from clinical reports has indicated that acupuncture has a promising effect on mild cognitive impairment (MCI. However, it is still unknown that by what way acupuncture can modulate brain networks involving the MCI. In the current study, multivariate Granger causality analysis (mGCA was adopted to compare the interregional effective connectivity of brain networks by varying needling depths (deep acupuncture, DA; superficial acupuncture, SA and at different cognitive states, which were the MCI and healthy control (HC. Results from DA at KI3 in MCI showed that the dorsolateral prefrontal cortex and hippocampus emerged as central hubs and had significant causal influences with each other, but significant in HC for DA. Moreover, only several brain regions had remarkable causal interactions following SA in MCI and even few brain regions following SA in HC. Our results indicated that acupuncture at KI3 at different cognitive states and with varying needling depths may induce distinct reorganizations of effective connectivities of brain networks, and DA at KI3 in MCI can induce the strongest and more extensive effective connectivities related to the therapeutic effect of acupuncture in MCI. The study demonstrated the relatively functional specificity of acupuncture at KI3 in MCI, and needling depths play an important role in acupuncture treatments.

  5. A developmental approach to learning causal models for cyber security

    Science.gov (United States)

    Mugan, Jonathan

    2013-05-01

    To keep pace with our adversaries, we must expand the scope of machine learning and reasoning to address the breadth of possible attacks. One approach is to employ an algorithm to learn a set of causal models that describes the entire cyber network and each host end node. Such a learning algorithm would run continuously on the system and monitor activity in real time. With a set of causal models, the algorithm could anticipate novel attacks, take actions to thwart them, and predict the second-order effects flood of information, and the algorithm would have to determine which streams of that flood were relevant in which situations. This paper will present the results of efforts toward the application of a developmental learning algorithm to the problem of cyber security. The algorithm is modeled on the principles of human developmental learning and is designed to allow an agent to learn about the computer system in which it resides through active exploration. Children are flexible learners who acquire knowledge by actively exploring their environment and making predictions about what they will find,1, 2 and our algorithm is inspired by the work of the developmental psychologist Jean Piaget.3 Piaget described how children construct knowledge in stages and learn new concepts on top of those they already know. Developmental learning allows our algorithm to focus on subsets of the environment that are most helpful for learning given its current knowledge. In experiments, the algorithm was able to learn the conditions for file exfiltration and use that knowledge to protect sensitive files.

  6. Structure and Connectivity Analysis of Financial Complex System Based on G-Causality Network

    Science.gov (United States)

    Xu, Chuan-Ming; Yan, Yan; Zhu, Xiao-Wu; Li, Xiao-Teng; Chen, Xiao-Song

    2013-11-01

    The recent financial crisis highlights the inherent weaknesses of the financial market. To explore the mechanism that maintains the financial market as a system, we study the interactions of U.S. financial market from the network perspective. Applied with conditional Granger causality network analysis, network density, in-degree and out-degree rankings are important indicators to analyze the conditional causal relationships among financial agents, and further to assess the stability of U.S. financial systems. It is found that the topological structure of G-causality network in U.S. financial market changed in different stages over the last decade, especially during the recent global financial crisis. Network density of the G-causality model is much higher during the period of 2007-2009 crisis stage, and it reaches the peak value in 2008, the most turbulent time in the crisis. Ranked by in-degrees and out-degrees, insurance companies are listed in the top of 68 financial institutions during the crisis. They act as the hubs which are more easily influenced by other financial institutions and simultaneously influence others during the global financial disturbance.

  7. Structure and Connectivity Analysis of Financial Complex System Based on G-Causality Network

    International Nuclear Information System (INIS)

    The recent financial crisis highlights the inherent weaknesses of the financial market. To explore the mechanism that maintains the financial market as a system, we study the interactions of U.S. financial market from the network perspective. Applied with conditional Granger causality network analysis, network density, in-degree and out-degree rankings are important indicators to analyze the conditional causal relationships among financial agents, and further to assess the stability of U.S. financial systems. It is found that the topological structure of G-causality network in U.S. financial market changed in different stages over the last decade, especially during the recent global financial crisis. Network density of the G-causality model is much higher during the period of 2007–2009 crisis stage, and it reaches the peak value in 2008, the most turbulent time in the crisis. Ranked by in-degrees and out-degrees, insurance companies are listed in the top of 68 financial institutions during the crisis. They act as the hubs which are more easily influenced by other financial institutions and simultaneously influence others during the global financial disturbance. (interdisciplinary physics and related areas of science and technology)

  8. Severidade da podridão-verde em inhames e especialização fisiológica em Penicillium sclerotigenum

    OpenAIRE

    Oliveira Idjane S. de; Luz Edna Dora. M. N.; Bezerra José Luiz; Moura Romero M.; Torres Gustavo R. C.; Maia Leonor C.

    2006-01-01

    Estudaram-se as reações do inhame Dioscorea alata cv. São Tomé e D. cayennensis cv. Da Costa em relação à severidade da podridão-verde, causada pelo fungo Penicillium sclerotigenum. Ao mesmo tempo, foi pesquisada à ocorrência de especialização fisiológica do agente causal, em relação à patogenicidade, nas mencionadas espécies de inhame. Para complementar esse estudo, analisou-se, in vitro, o crescimento micelial de P. sclerotigenum em três meios de cultura semi-sintéticos, sendo dois à base d...

  9. Avaliação clínica de novo agente inibidor da monaminoxidase em pacientes hospitalizados Clinical essay with a-methyl-benzylhydrazine in in-patients

    Directory of Open Access Journals (Sweden)

    Walter Stoiani

    1967-12-01

    Full Text Available É experimentado um novo agente inibidor da monaminoxidase, a a-metil-benzilidrazina. Foram estudados 20 pacientes com quadros depressivos (endógenos, involutivos, reativos, neuróticos e sintomáticos no curso de psicoses diversas. O medicamento foi utilizado em doses que variaram entre 10 e 20 mg/dia, por via oral, em período que oscilou de 20 a 90 dias. Foi adotado o método de observação clínico-analítica na avaliação dos resultados. As melhores respostas terapêuticas foram observadas nos pacientes com depressão reativa e, a seguir, nos casos de depressão involutiva e neurótica. As depressões surgidas no decurso de diferentes psicoses foram influenciadas de modo menos regular, sendo em geral pouco melhoradas ou não sofrendo qualquer influência.The results with a new monoamine oxidase inhibitor (a-methyl-benzylhydrazine on 20 depressed patients are reported. The doses used orally ranged from 10 to 20 mg/day, during 20 to 90 days. The evalutation was made on the basis of clinical analytic observation. The results were as follow: very good improvement in 5 cases; 7 cases with good results; 4 cases with moderate improvement; 4 cases remained unchanged. The best results were observed in patients with reactive depression. Good results were observed in involutional and neurotic depressions. The symptomatic depressions arisig in the course of various psychoses were hardly, or not at all, influenced by the drug. Severe side effects were not present, except transitory jaundice observed in one case. The authors concluded that a-methyl-benzylhydrazine is a useful antidepressant drug in the treitment of depression, specially in reactive psychoses.

  10. O nexo causal em saúde/doença mental no trabalho: uma demanda para a psicologia The causal nexus on mental health/illness related to work: a new demand for psychology

    Directory of Open Access Journals (Sweden)

    Maria da Graça Jacques

    2007-01-01

    Full Text Available Estabelecer o nexo causal em saúde/doença mental no trabalho tem se apresentado como uma nova demanda à psicologia como ciência e profissão nos seus diferentes campos de atuação. Este texto examina a interlocução entre trabalho e saúde/doença mental no percurso histórico da psicologia. Apresenta, também, alguns procedimentos referentes ao diagnóstico e à justificativa de nexo causal entre trabalho e quadros psicopatológicos com base na Portaria do 1339/99 do Ministério da Saúde do Brasil. Mesmo admitindo o reducionismo que a relação causal produz em se tratando de quadros psicopatológicos, a exigência legal a impõe para o reconhecimento como doenças relacionadas com o trabalho e o acesso aos benefícios previdenciários decorrentes.Establishing the causal nexus on mental health/illness related to work is a new demand for psychology as a science and as a profession in all fields of activity. This text examines the interlocution between work and mental health/illness in the course of the history of psychology. It also presents some procedures referring to the diagnosis and the justification of the causal nexus between work and psychopathological illness. Even if we consider the causal nexus as a reductionism in psychopathological illness, this is a legal requirement to be recognized as an illness related to work and to obtain social welfare agency benefits.

  11. Antibiotic Agents

    Science.gov (United States)

    ... either as public health or as non-public health antimicrobial agents. What is the difference between bacteriostats, sanitizers, disinfectants ... bacteria, however, there is considerable controversy surrounding their health benefits. The ... producing agents (Table of Antibacterials) have been used for many ...

  12. Identifying causal variants at loci with multiple signals of association.

    Science.gov (United States)

    Hormozdiari, Farhad; Kostem, Emrah; Kang, Eun Yong; Pasaniuc, Bogdan; Eskin, Eleazar

    2014-10-01

    Although genome-wide association studies have successfully identified thousands of risk loci for complex traits, only a handful of the biologically causal variants, responsible for association at these loci, have been successfully identified. Current statistical methods for identifying causal variants at risk loci either use the strength of the association signal in an iterative conditioning framework or estimate probabilities for variants to be causal. A main drawback of existing methods is that they rely on the simplifying assumption of a single causal variant at each risk locus, which is typically invalid at many risk loci. In this work, we propose a new statistical framework that allows for the possibility of an arbitrary number of causal variants when estimating the posterior probability of a variant being causal. A direct benefit of our approach is that we predict a set of variants for each locus that under reasonable assumptions will contain all of the true causal variants with a high confidence level (e.g., 95%) even when the locus contains multiple causal variants. We use simulations to show that our approach provides 20-50% improvement in our ability to identify the causal variants compared to the existing methods at loci harboring multiple causal variants. We validate our approach using empirical data from an expression QTL study of CHI3L2 to identify new causal variants that affect gene expression at this locus. CAVIAR is publicly available online at http://genetics.cs.ucla.edu/caviar/. PMID:25104515

  13. Temporal Information of Directed Causal Connectivity in Multi-Trial ERP Data using Partial Granger Causality.

    Science.gov (United States)

    Youssofzadeh, Vahab; Prasad, Girijesh; Naeem, Muhammad; Wong-Lin, KongFatt

    2016-01-01

    Partial Granger causality (PGC) has been applied to analyse causal functional neural connectivity after effectively mitigating confounding influences caused by endogenous latent variables and exogenous environmental inputs. However, it is not known how this connectivity obtained from PGC evolves over time. Furthermore, PGC has yet to be tested on realistic nonlinear neural circuit models and multi-trial event-related potentials (ERPs) data. In this work, we first applied a time-domain PGC technique to evaluate simulated neural circuit models, and demonstrated that the PGC measure is more accurate and robust in detecting connectivity patterns as compared to conditional Granger causality and partial directed coherence, especially when the circuit is intrinsically nonlinear. Moreover, the connectivity in PGC settles faster into a stable and correct configuration over time. After method verification, we applied PGC to reveal the causal connections of ERP trials of a mismatch negativity auditory oddball paradigm. The PGC analysis revealed a significant bilateral but asymmetrical localised activity in the temporal lobe close to the auditory cortex, and causal influences in the frontal, parietal and cingulate cortical areas, consistent with previous studies. Interestingly, the time to reach a stable connectivity configuration (~250–300 ms) coincides with the deviation of ensemble ERPs of oddball from standard tones. Finally, using a sliding time window, we showed higher resolution dynamics of causal connectivity within an ERP trial. In summary, time-domain PGC is promising in deciphering directed functional connectivity in nonlinear and ERP trials accurately, and at a sufficiently early stage. This data-driven approach can reduce computational time, and determine the key architecture for neural circuit modeling. PMID:26470866

  14. Causal Depth: Aspects of a Scientific Realist Approach to Causal Explanation contra Humean Empiricism

    OpenAIRE

    Khan, Haider

    2008-01-01

    The purpose of this note is to clarify how the idea of "causal depth" can play a role in finding the more "approximately true" explanation through causal comparisons. It is not an exhaustive treatment but rather focuses on a few aspects that may be the most critical in evaluating the explanatory strengths of a theory in the social sciences. It presents a general argument which is anti-Humean on the critical side and scientific realist on the positive side. It also elucidates how explanations ...

  15. The Causality between Human Capital and Economic Growth in Oil Exporting Countries: Panel Cointegration and Causality

    OpenAIRE

    Mehrara, Mohsen

    2013-01-01

    This paper investigates the causal relationship between education and GDP in a panel of 11 selected oil exporting countries by using panel unit root tests and panel cointegration analysis for the period 1970-2010. A three-variable model is formulated with oil exports as the third variable. The results show a strong causality from oil revenues and economic growth to education in the oil exporting countries. Yet, education does not have any significant effects on GDP in short- and long-run. It ...

  16. Causal Loop Analysis of coastal geomorphological systems

    Science.gov (United States)

    Payo, Andres; Hall, Jim W.; French, Jon; Sutherland, James; van Maanen, Barend; Nicholls, Robert J.; Reeve, Dominic E.

    2016-03-01

    As geomorphologists embrace ever more sophisticated theoretical frameworks that shift from simple notions of evolution towards single steady equilibria to recognise the possibility of multiple response pathways and outcomes, morphodynamic modellers are facing the problem of how to keep track of an ever-greater number of system feedbacks. Within coastal geomorphology, capturing these feedbacks is critically important, especially as the focus of activity shifts from reductionist models founded on sediment transport fundamentals to more synthesist ones intended to resolve emergent behaviours at decadal to centennial scales. This paper addresses the challenge of mapping the feedback structure of processes controlling geomorphic system behaviour with reference to illustrative applications of Causal Loop Analysis at two study cases: (1) the erosion-accretion behaviour of graded (mixed) sediment beds, and (2) the local alongshore sediment fluxes of sand-rich shorelines. These case study examples are chosen on account of their central role in the quantitative modelling of geomorphological futures and as they illustrate different types of causation. Causal loop diagrams, a form of directed graph, are used to distil the feedback structure to reveal, in advance of more quantitative modelling, multi-response pathways and multiple outcomes. In the case of graded sediment bed, up to three different outcomes (no response, and two disequilibrium states) can be derived from a simple qualitative stability analysis. For the sand-rich local shoreline behaviour case, two fundamentally different responses of the shoreline (diffusive and anti-diffusive), triggered by small changes of the shoreline cross-shore position, can be inferred purely through analysis of the causal pathways. Explicit depiction of feedback-structure diagrams is beneficial when developing numerical models to explore coastal morphological futures. By explicitly mapping the feedbacks included and neglected within a

  17. Foundational perspectives on causality in large-scale brain networks

    Science.gov (United States)

    Mannino, Michael; Bressler, Steven L.

    2015-12-01

    A profusion of recent work in cognitive neuroscience has been concerned with the endeavor to uncover causal influences in large-scale brain networks. However, despite the fact that many papers give a nod to the important theoretical challenges posed by the concept of causality, this explosion of research has generally not been accompanied by a rigorous conceptual analysis of the nature of causality in the brain. This review provides both a descriptive and prescriptive account of the nature of causality as found within and between large-scale brain networks. In short, it seeks to clarify the concept of causality in large-scale brain networks both philosophically and scientifically. This is accomplished by briefly reviewing the rich philosophical history of work on causality, especially focusing on contributions by David Hume, Immanuel Kant, Bertrand Russell, and Christopher Hitchcock. We go on to discuss the impact that various interpretations of modern physics have had on our understanding of causality. Throughout all this, a central focus is the distinction between theories of deterministic causality (DC), whereby causes uniquely determine their effects, and probabilistic causality (PC), whereby causes change the probability of occurrence of their effects. We argue that, given the topological complexity of its large-scale connectivity, the brain should be considered as a complex system and its causal influences treated as probabilistic in nature. We conclude that PC is well suited for explaining causality in the brain for three reasons: (1) brain causality is often mutual; (2) connectional convergence dictates that only rarely is the activity of one neuronal population uniquely determined by another one; and (3) the causal influences exerted between neuronal populations may not have observable effects. A number of different techniques are currently available to characterize causal influence in the brain. Typically, these techniques quantify the statistical

  18. On asymmetric causal relationships in Petropolitics

    Directory of Open Access Journals (Sweden)

    Balan Feyza

    2016-01-01

    Full Text Available The aim of this paper is to examine whether the First Law of Petropolitics denominated by Friedman in 2006 is valid for OPEC countries. To do this, this paper analyses the relationship between political risk and oil supply by applying the asymmetric panel causality test suggested by Hatemi-J (2011 to these countries for the period 1984-2014. The results show that the First Law of Petropolitics is valid for Angola, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, and the UAE, given that positive oil supply shocks significantly lead to negative political stability shocks, and negative oil supply shocks significantly lead to positive shocks in political stability.

  19. Rapidity Correlation Structures from Causal Hydrodynamics

    CERN Document Server

    Gavin, Sean; Zin, Christopher

    2016-01-01

    Viscous diffusion can broaden the rapidity dependence of two-particle transverse momentum fluctuations. Surprisingly, measurements at RHIC by the STAR collaboration demonstrate that this broadening is accompanied by the appearance of unanticipated structure in the rapidity distribution of these fluctuations in the most central collisions. Although a first order classical Navier-Stokes theory can roughly explain the rapidity broadening, it cannot explain the additional structure. We propose that the rapidity structure can be explained using the second order causal Israel-Stewart hydrodynamics with stochastic noise.

  20. Causality Green functions of bilocal fields

    International Nuclear Information System (INIS)

    It is shown by concrete examples, that the threshold value k-1 = 0 in the field quantum theory with three universal constants c, h, k, proposed in an other work, corresponding to the local theory, constitutes the bifurcation point: the causality Green function by the k finite value bifurcates into two parts: D-tildeLC and D-tildeEC. The Euclidean space-time R4 is a natural carrier of the latter one; its continuation from R4 onto R3.1 is regular, whereas the first one is singular in the zero and on the light cone and therefore it is rejected

  1. Método para preservação da viabilidade e atividade antagônica de Trichoderma stromaticum , agente de biocontrole da vassoura-de-bruxa do cacaueiro Method for preservation of viability and antagonic activity of Trichoderma stromaticum, biocontrol agent of witches´broom disease of cocoa

    Directory of Open Access Journals (Sweden)

    Cleber Novais Bastos

    2008-09-01

    Full Text Available Avaliou-se a viabilidade da massa esporógena de Trichoderma stromaticum, através do crescimento micelial em meio de cultivo e a atividade antagônica (parasitária em vassouras secas de cacaueiro, após a preservação de quatro isolados (Ts1606, Ts3107, Ts0108, Ts2705 do antagonista por quatro anos em fragmentos de vassoura secas, acondicionados em tubos de ensaio e mantidos em refrigerador com temperatura aproximada de 5 °C. Todos os isolados preservados apresentaram-se viáveis, com crescimento e esporulação normais e continuavam antagônicos a Crinipellis perniciosa. Os resultados obtidos indicam a eficiência do método, que é capaz de manter os isolados de T. stromaticum viáveis por longos períodos de tempo, preservando características morfológicas, fisiológicas e antagônicas.After four years of preservation by using dried cocoa brooms in fridge at 5 °C, the viability of four isolates (Ts1606, Ts3107, Ts0108, Ts2705 of Trichoderma stromaticum was evaluated based on germination of conidia, mycelium growth in a culture medium and antagonistic activity on dry cocoa brooms. All the isolates preserved maintained viability, showing normal growth, sporulation and antagonistic activity against Crinipellis perniciosa.. These results indicate the efficience of the method for the long term preservation of T. stromaticum, maintaining their morphological, physiological, and antagonistic characteristics.

  2. Infraestrutura de biossegurança para agentes biológicos em hospitais do sul do Estado da Bahia, Brasil Infraesctructura de bioseguridad para los agentes biológicos en hospitales del sur del Estado de Bahia, Brasil Biosecurity infrastructure for biological agents in hospitals from the south of Bahia State, Brazil

    OpenAIRE

    Maridalva de Souza Penteado; Tânia Cristina de Oliveira

    2010-01-01

    O objetivo do estudo foi descrever a infraestrutura de biossegurança em hospitais localizados na Região Sul do Estado da Bahia, Brasil. Tratou-se de um estudo descritivo-exploratório realizado em comissões de controle de infecções hospitalares e comissão institucional de prevenção a acidentes quanto à existência de normas escritas, realização de treinamentos para essas mesmas preconizações, existência de registros institucionais concernentes à biossegurança e existência de práticas de atenção...

  3. O Programa de Controle do Dengue em São José do Rio Preto, São Paulo, Brasil: dificuldades para a atuação dos agentes e adesão da população Dengue Control Program in São José do Rio Preto, São Paulo State, Brazil: problems with health agents' work and population adherence

    Directory of Open Access Journals (Sweden)

    Francisco Chiaravalloti Neto

    2007-07-01

    Full Text Available O objetivo do trabalho foi identificar aspectos que interferem na atuação dos agentes de controle de vetores e comunitários de saúde no Programa de Controle do Dengue e na adesão da população. Utilizou-se metodologia de grupos focais, nos quais foi discutida a relação agente-serviço-população. O controle e prevenção do dengue foram considerados atividades de menor importância, e o agente ideal seria aquele capaz de encaminhar todas as demandas e não só aquelas relacionadas ao dengue. Os agentes de controle de vetores apontaram para problemas como recusa e falta de adesão, identificação como coletores de lixo, diferenciação de status em relação aos agentes comunitários de saúde. Entre as mulheres, identificaram-se a relação de culpabilização entre vizinhos, a associação do problema do dengue à falta de higiene e a relação entre casa limpa e ausência de criadouros. Os aspectos destacados interferem negativamente na atuação dos agentes e são condicionados pela característica vertical do programa. Encaminhamentos possíveis: incorporação dos agentes de controle às Unidades de Saúde, investimento na integração intersetorial e criação de condições para que os agentes atuem sobre o meio ambiente.This study aimed to identify the aspects that interfere with the performance of vector control agents and community health workers and population adherence to dengue control programs. The focal group methodology was applied to discuss the relations between the program, health agents, and population. According to the results, dengue control and prevention were considered relatively unimportant activities, i.e., ideal community health workers would be capable of solving other (supposedly more important problems. Vector control agents emphasized the population's lack of adherence and the fact that they (the control agents were confused with garbage collectors (considered less important than community health workers

  4. Aspectos morfológicos da colonização de Colletotrichum gloeosporioides em órgãos de plantas de cafeeiros e com sintomas da mancha manteigosa Morphologic aspects of colonization of Colletotrichum gloeosporioides on organs of coffee plants with blister spot

    Directory of Open Access Journals (Sweden)

    Josimar Batista Ferreira

    2009-08-01

    Full Text Available Objetivou-se, no presente trabalho, analisar microscopicamente a colonização de C. gloeosporioides, agente da mancha manteigosa (MM, em condições naturais da doença, sobre os diferentes órgãos e tecidos da cultivar Catucaí Vermelho: folhas, pecíolos, nervuras, ramos, frutos e pedúnculos. Todas as amostras foram processadas, obtendo-se imagens em microscópico eletrônico de varredura. Os ramos e as nervuras de folhas de cafeeiros com mancha manteigosa apresentando morte descendente e hipocótilos oriundos de sementes têm os vasos do xilema, floema e células do córtex colonizados por C. gloeosporioides, já os frutos com sintoma da mancha manteigosa apresentaram colonização nos tecidos do exocarpo, mesocarpo, endocarpo e endosperma.The aim of this work was to study the colonization of leaves, petioles, veins, branches, fruits, and peduncles by C. gloeosporioides, the causal agent of blister spot, under natural infections of cultivar Catucaí Vermelho in field conditions. All materials were analyzed through scanning electron microscopy. The branches and veins of coffee leaves affected by blister spot with descending death as well as hypocotyls from seedlings had their xylem, phloem and cortical cells colonized by C. gloeosporioides while fruits showing blister spot symptoms had their exocarp, mesocarp, endocarp, and endosperm tissues colonized by C. gloeosporioides.

  5. Trivariate causality between economic growth, urbanisation and electricity consumption in Angola: Cointegration and causality analysis

    International Nuclear Information System (INIS)

    This paper investigates the causal relationship between economic growth, urbanisation and electricity consumption in the case of Angola, while utilizing the data over the period of 1971–2009. We have applied Lee and Strazicich (2003. The Review of Economics and Statistics 63, 1082–1089; 2004. Working Paper. Department of Economics, Appalachian State University) unit root tests to examine the stationarity properties of the series. Using the Gregory–Hansen structural break cointegration procedure as a complement, we employ the ARDL bounds test to investigate long run relationships. The VECM Granger causality test is subsequently used to examine the direction of causality between economic growth, urbanisation, and electricity consumption. Our results indicate the existence of long run relationships. We further observe evidence in favour of bidirectional causality between electricity consumption and economic growth. The feedback hypothesis is also found between urbanisation and economic growth. Urbanisation and electricity consumption Granger cause each other. We conclude that Angola is energy-dependent country. Consequently, the relevant authorities should boost electricity production as one of the means of achieving sustainable economic development in the long run. - Highlights: • We consider the link between electricity consumption and economic growth in Angola. • Urbanisation is added to turn the research into a trivariate investigation. • Various time series procedures are used. • Results show that increasing electricity will improve economic growth in Angola. • Results show urbanisations reduced economic growth during civil war

  6. Interference between Cues Requires a Causal Scenario: Favorable Evidence for Causal Reasoning Models in Learning Processes

    Science.gov (United States)

    Luque, David; Cobos, Pedro L.; Lopez, Francisco J.

    2008-01-01

    In an interference-between-cues design (IbC), the expression of a learned Cue A-Outcome 1 association has been shown to be impaired if another cue, B, is separately paired with the same outcome in a second learning phase. The present study examined whether IbC could be caused by associative mechanisms independent of causal reasoning processes.…

  7. Causal-Explanatory Pluralism: How Intentions, Functions, and Mechanisms Influence Causal Ascriptions

    Science.gov (United States)

    Lombrozo, Tania

    2010-01-01

    Both philosophers and psychologists have argued for the existence of distinct kinds of explanations, including teleological explanations that cite functions or goals, and mechanistic explanations that cite causal mechanisms. Theories of causation, in contrast, have generally been unitary, with dominant theories focusing either on counterfactual…

  8. Causal mechanisms in airfoil-circulation formation

    Science.gov (United States)

    Zhu, J. Y.; Liu, T. S.; Liu, L. Q.; Zou, S. F.; Wu, J. Z.

    2015-12-01

    In this paper, we trace the dynamic origin, rather than any kinematic interpretations, of lift in two-dimensional flow to the physical root of airfoil circulation. We show that the key causal process is the vorticity creation by tangent pressure gradient at the airfoil surface via no-slip condition, of which the theoretical basis has been given by Lighthill ["Introduction: Boundary layer theory," in Laminar Boundary Layers, edited by L. Rosenhead (Clarendon Press, 1963), pp. 46-113], which we further elaborate. This mechanism can be clearly revealed in terms of vorticity formulation but is hidden in conventional momentum formulation, and hence has long been missing in the history of one's efforts to understand lift. By a careful numerical simulation of the flow around a NACA-0012 airfoil, and using both Eulerian and Lagrangian descriptions, we illustrate the detailed transient process by which the airfoil gains its circulation and demonstrate the dominating role of relevant dynamical causal mechanisms at the boundary. In so doing, we find that the various statements for the establishment of Kutta condition in steady inviscid flow actually correspond to a sequence of events in unsteady viscous flow.

  9. Introducing mechanics by tapping core causal knowledge

    International Nuclear Information System (INIS)

    This article concerns an outline of an introductory mechanics course. It is based on the argument that various uses of the concept of force (e.g. from Kepler, Newton and everyday life) share an explanatory strategy based on core causal knowledge. The strategy consists of (a) the idea that a force causes a deviation from how an object would move of its own accord (i.e. its force-free motion), and (b) an incentive to search, where the motion deviates from the assumed force-free motion, for recurring configurations with which such deviations can be correlated (interaction theory). Various assumptions can be made concerning both the force-free motion and the interaction theory, thus giving rise to a variety of specific explanations. Kepler's semi-implicit intuition about the force-free motion is rest, Newton's explicit assumption is uniform rectilinear motion, while in everyday explanations a diversity of pragmatic suggestions can be recognized. The idea is that the explanatory strategy, once made explicit by drawing on students' intuitive causal knowledge, can be made to function for students as an advance organizer, in the sense of a general scheme that they recognize but do not yet know how to detail for scientific purposes

  10. Emergent Horizons and Causal Structures in Holography

    CERN Document Server

    Banerjee, Avik; Kundu, Sandipan

    2016-01-01

    The open string metric arises kinematically in studying fluctuations of open string degrees of freedom on a D-brane. An observer, living on a probe D-brane, can send signals through the spacetime by using such fluctuations on the probe, that propagate in accordance with a metric which is conformal to the open string metric. Event horizons can emerge in the open string metric when one considers a D-brane with an electric field on its worldvolume. Here, we emphasize the role of and investigate, in details, the causal structure of the resulting open string event horizon and demonstrate, among other things, its close similarities to an usual black hole event horizon in asymptotically AdS-spaces. To that end, we analyze relevant geodesics, Penrose diagrams and various causal holographic observables for a given open string metric. For analytical control, most of our calculations are performed in an asymptotically AdS$_3$-background, however, we argue that the physics is qualitatively the same in higher dimensions. ...

  11. Diagnostic reasoning using qualitative causal models

    International Nuclear Information System (INIS)

    The application of expert systems to reasoning problems involving real-time data from plant measurements has been a topic of much research, but few practical systems have been deployed. One obstacle to wider use of expert systems in applications involving real-time data is the lack of adequate knowledge representation methodologies for dynamic processes. Knowledge bases composed mainly of rules have disadvantages when applied to dynamic processes and real-time data. This paper describes a methodology for the development of qualitative causal models that can be used as knowledge bases for reasoning about process dynamic behavior. These models provide a systematic method for knowledge base construction, considerably reducing the engineering effort required. They also offer much better opportunities for verification and validation of the knowledge base, thus increasing the possibility of the application of expert systems to reasoning about mission critical systems. Starting with the Signed Directed Graph (SDG) method that has been successfully applied to describe the behavior of diverse dynamic processes, the paper shows how certain non-physical behaviors that result from abstraction may be eliminated by applying causal constraint to the models. The resulting Extended Signed Directed Graph (ESDG) may then be compiled to produce a model for use in process fault diagnosis. This model based reasoning methodology is used in the MOBIAS system being developed by Duke Power Company under EPRI sponsorship. 15 refs., 4 figs

  12. EEG oscillations: From correlation to causality.

    Science.gov (United States)

    Herrmann, Christoph S; Strüber, Daniel; Helfrich, Randolph F; Engel, Andreas K

    2016-05-01

    Already in his first report on the discovery of the human EEG in 1929, Berger showed great interest in further elucidating the functional roles of the alpha and beta waves for normal mental activities. Meanwhile, most cognitive processes have been linked to at least one of the traditional frequency bands in the delta, theta, alpha, beta, and gamma range. Although the existing wealth of high-quality correlative EEG data led many researchers to the conviction that brain oscillations subserve various sensory and cognitive processes, a causal role can only be demonstrated by directly modulating such oscillatory signals. In this review, we highlight several methods to selectively modulate neuronal oscillations, including EEG-neurofeedback, rhythmic sensory stimulation, repetitive transcranial magnetic stimulation (rTMS), and transcranial alternating current stimulation (tACS). In particular, we discuss tACS as the most recent technique to directly modulate oscillatory brain activity. Such studies demonstrating the effectiveness of tACS comprise reports on purely behavioral or purely electrophysiological effects, on combination of behavioral effects with offline EEG measurements or on simultaneous (online) tACS-EEG recordings. Whereas most tACS studies are designed to modulate ongoing rhythmic brain activity at a specific frequency, recent evidence suggests that tACS may also modulate cross-frequency interactions. Taken together, the modulation of neuronal oscillations allows to demonstrate causal links between brain oscillations and cognitive processes and to obtain important insights into human brain function. PMID:25659527

  13. Evidence for online processing during causal learning.

    Science.gov (United States)

    Liu, Pei-Pei; Luhmann, Christian C

    2015-03-01

    Many models of learning describe both the end product of learning (e.g., causal judgments) and the cognitive mechanisms that unfold on a trial-by-trial basis. However, the methods employed in the literature typically provide only indirect evidence about the unfolding cognitive processes. Here, we utilized a simultaneous secondary task to measure cognitive processing during a straightforward causal-learning task. The results from three experiments demonstrated that covariation information is not subject to uniform cognitive processing. Instead, we observed systematic variation in the processing dedicated to individual pieces of covariation information. In particular, observations that are inconsistent with previously presented covariation information appear to elicit greater cognitive processing than do observations that are consistent with previously presented covariation information. In addition, the degree of cognitive processing appears to be driven by learning per se, rather than by nonlearning processes such as memory and attention. Overall, these findings suggest that monitoring learning processes at a finer level may provide useful psychological insights into the nature of learning. PMID:25488021

  14. Análisis proteómico de Plasmodium, el agente causal de la malaria Proteomic analysis of Plasmodium, the causal agent of Malaria

    Directory of Open Access Journals (Sweden)

    Ivone Castro R

    2009-01-01

    Full Text Available Los plasmodios son protozoarios cuyo complejo ciclo de vida se lleva a cabo en dos hospederos, el vertebrado y el mosquito. La infección de los seres humanos produce la enfermedad conocida como malaria. La secuenciación del genoma de Plasmodium falciparum y el desarrollo de la proteómica han permitido un gran avance en el conocimiento de la biología de este letal parásito. La presente revisión se centra en describir los logros recientes en el estudio del proteoma de Plasmodium falciparum y algunas de las implicaciones en la búsqueda de nuevos fármacos antimaláricos, así como en la generación de vacunas para el control de la enfermedad.Plasmodia are protozoa whose complex life cycle takes place in two different hosts, the vertebrate and the mosquito. The human infection produces the malaria disease. The genome sequence of Plasmodium falciparum and the proteomic tools have enabled a huge advance in knowledge of the biology of this parasite. This review will focus on the recent advances in proteomic studies of Plasmodium falciparum and some implications for the search of new antimalarial drugs as well as vaccines for the control of the disease.

  15. Causal Conclusions that Flip Repeatedly and Their Justification

    CERN Document Server

    Kelly, Kevin T

    2012-01-01

    Over the past two decades, several consis- tent procedures have been designed to infer causal conclusions from observational data. We prove that if the true causal network might be an arbitrary, linear Gaussian net- work or a discrete Bayes network, then every unambiguous causal conclusion produced by a consistent method from non-experimental data is subject to reversal as the sample size increases any finite number of times. That result, called the causal flipping theorem, ex- tends prior results to the effect that causal discovery cannot be reliable on a given sam- ple size. We argue that since repeated flipping of causal conclusions is unavoidable in principle for consistent methods, the best possible discovery methods are consistent methods that retract their earlier conclusions no more than necessary. A series of sim- ulations of various methods across a wide range of sample sizes illustrates concretely both the theorem and the principle of com- paring methods in terms of retractions.

  16. Comparison Analysis: Granger Causality and New Causality and Their Applications to Motor Imagery.

    Science.gov (United States)

    Hu, Sanqing; Wang, Hui; Zhang, Jianhai; Kong, Wanzeng; Cao, Yu; Kozma, Robert

    2016-07-01

    In this paper we first point out a fatal drawback that the widely used Granger causality (GC) needs to estimate the autoregressive model, which is equivalent to taking a series of backward recursive operations which are infeasible in many irreversible chemical reaction models. Thus, new causality (NC) proposed by Hu et al. (2011) is theoretically shown to be more sensitive to reveal true causality than GC. We then apply GC and NC to motor imagery (MI) which is an important mental process in cognitive neuroscience and psychology and has received growing attention for a long time. We study causality flow during MI using scalp electroencephalograms from nine subjects in Brain-computer interface competition IV held in 2008. We are interested in three regions: Cz (central area of the cerebral cortex), C3 (left area of the cerebral cortex), and C4 (right area of the cerebral cortex) which are considered to be optimal locations for recognizing MI states in the literature. Our results show that: 1) there is strong directional connectivity from Cz to C3/C4 during left- and right-hand MIs based on GC and NC; 2) during left-hand MI, there is directional connectivity from C4 to C3 based on GC and NC; 3) during right-hand MI, there is strong directional connectivity from C3 to C4 which is much clearly revealed by NC than by GC, i.e., NC largely improves the classification rate; and 4) NC is demonstrated to be much more sensitive to reveal causal influence between different brain regions than GC. PMID:26099149

  17. Alterações funcionais da junção neuromuscular provocadas em ratos pela administração diária e prolongada de um agente curarizante

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Zanini

    1967-06-01

    Full Text Available A ratos adultos, machos, foi administrado durante 8 semanas, uma vez ao dia, o iodeto do dimetiléter da d-tubocurarina (DMT, pela via intraperitoneal. Os animais foram distribuídos em 3 lotes: os do 1.°, receberam 5,5 gama de DMT/kg/dia; os do 2.°, 16,6 gama/kg/dia; os do 3.° (controle, 1 ml da solução isotônica de cloreto de sódio. A força muscular dos animais foi avaliada uma vez por semana, de acordo com o método descrito no texto, antes e após a injeção intraperitoneal da referida substância. Com o decorrer da experimentação, observou-se que: a houve diminuição significativa da força muscular dos animais, avaliada após esvaecimento da atividade curarizante do DMT; b a determinação da força muscular, feita logo após a injeção, mostrou que a dose de 5,5 gama/kg/dia provoca um aumento da suscetibilidade dos animais à ação curarizante do DMT; c o efeito inibidor provocado pela dose de 16,6 gama/kg/dia de DMT aumentou no início mas diminuiu significantemente após a 5ª semana, muito embora houvesse uma progressiva diminuição da força muscular, sugerindo independência entre os dois efeitos. Com base nesses resultados, são discutidos alguns fenômenos que podem ocorrer na instalação e tratamento da miastenia grave.

  18. On the causal structure between CO2 and global temperature

    OpenAIRE

    Adolf Stips; Diego Macias; Clare Coughlan; Elisa Garcia-Gorriz; X. San Liang

    2016-01-01

    We use a newly developed technique that is based on the information flow concept to investigate the causal structure between the global radiative forcing and the annual global mean surface temperature anomalies (GMTA) since 1850. Our study unambiguously shows one-way causality between the total Greenhouse Gases and GMTA. Specifically, it is confirmed that the former, especially CO2, are the main causal drivers of the recent warming. A significant but smaller information flow comes from aeroso...

  19. Non-parametric causal inference for bivariate time series

    CERN Document Server

    McCracken, James M

    2015-01-01

    We introduce new quantities for exploratory causal inference between bivariate time series. The quantities, called penchants and leanings, are computationally straightforward to apply, follow directly from assumptions of probabilistic causality, do not depend on any assumed models for the time series generating process, and do not rely on any embedding procedures; these features may provide a clearer interpretation of the results than those from existing time series causality tools. The penchant and leaning are computed based on a structured method for computing probabilities.

  20. Finance and Growth: Institutional Considerations, Financial Policies and Causality

    OpenAIRE

    Philip Arestis; Panicos Demetriades

    1999-01-01

    Authors in this article suggest that country specific institutional factors and policies are likely to influence the causal nature of the relationship between financial development and economic growth. Authors conduct cointegration and causality tests using time series data for twelve representative countries. The empirical results show considerable variation of causality across countries which can be explained by institutional and policy differences, providing support to the main hypothesis.

  1. Causality, Unintended Consequences and Deducing Shared Causes

    OpenAIRE

    Steven M. Shugan

    2007-01-01

    Despite warnings against inferring causality from observed correlations or statistical dependence, some articles do. Observed correlation is neither necessary nor sufficient to infer causality as defined by the term's everyday usage. For example, a deterministic causal process creates pseudorandom numbers; yet, we observe no correlation between the numbers. Child height correlates with spelling ability because age causes both. Moreover, order is problematic—we hear train whistles before obser...

  2. Dark matter perturbations and viscosity: a causal approach

    OpenAIRE

    Acquaviva, Giovanni; John, Anslyn; Pénin, Aurélie

    2016-01-01

    The inclusion of dissipative effects in cosmic fluids modifies their clustering properties and could have observable effects on the formation of large scale structures. We analyse the evolution of density perturbations of cold dark matter endowed with causal bulk viscosity. The perturbative analysis is carried out in the Newtonian approximation and the bulk viscosity is described by the causal Israel-Stewart (IS) theory. In contrast to the non-causal Eckart theory, we obtain a third order evo...

  3. The Causality between Government Revenue and Government Expenditure in Iran

    OpenAIRE

    2012-01-01

    The causal relationship between government revenue and government expenditure is an important subject in public economics especially to the control of budget deficit. The purpose of this study is to investigate the relationship between government revenue and government expenditure in Iran by applying the bounds testing approach to cointegration. The results of the causality test show that there is a bidirectional causal relationship between government expenditure and revenues in both long run...

  4. Integrating Probabilistic, Taxonomic and Causal Knowledge in Abductive Diagnosis

    OpenAIRE

    Lin, Dekang; Goebel, Randy

    2013-01-01

    We propose an abductive diagnosis theory that integrates probabilistic, causal and taxonomic knowledge. Probabilistic knowledge allows us to select the most likely explanation; causal knowledge allows us to make reasonable independence assumptions; taxonomic knowledge allows causation to be modeled at different levels of detail, and allows observations be described in different levels of precision. Unlike most other approaches where a causal explanation is a hypothesis that one or more causat...

  5. A general, multivariate definition of causal effects in epidemiology.

    Science.gov (United States)

    Flanders, W Dana; Klein, Mitchel

    2015-07-01

    Population causal effects are often defined as contrasts of average individual-level counterfactual outcomes, comparing different exposure levels. Common examples include causal risk difference and risk ratios. These and most other examples emphasize effects on disease onset, a reflection of the usual epidemiological interest in disease occurrence. Exposure effects on other health characteristics, such as prevalence or conditional risk of a particular disability, can be important as well, but contrasts involving these other measures may often be dismissed as non-causal. For example, an observed prevalence ratio might often viewed as an estimator of a causal incidence ratio and hence subject to bias. In this manuscript, we provide and evaluate a definition of causal effects that generalizes those previously available. A key part of the generalization is that contrasts used in the definition can involve multivariate, counterfactual outcomes, rather than only univariate outcomes. An important consequence of our generalization is that, using it, one can properly define causal effects based on a wide variety of additional measures. Examples include causal prevalence ratios and differences and causal conditional risk ratios and differences. We illustrate how these additional measures can be useful, natural, easily estimated, and of public health importance. Furthermore, we discuss conditions for valid estimation of each type of causal effect, and how improper interpretation or inferences for the wrong target population can be sources of bias. PMID:25946227

  6. Causal topology in future and past distinguishing spacetimes

    International Nuclear Information System (INIS)

    The causal structure of a strongly causal spacetime is particularly well endowed. Not only does it determine the conformal spacetime geometry when the spacetime dimension n > 2, as shown by Malament and Hawking-King-McCarthy (MHKM), but also the manifold dimension. The MHKM result, however, applies more generally to spacetimes satisfying the weaker causality condition of future and past distinguishability (FPD), and it is an important question whether the causal structure of such spacetimes can determine the manifold dimension. In this work, we show that the answer to this question is in the affirmative. We investigate the properties of future or past distinguishing spacetimes and show that their causal structures determine the manifold dimension. This gives a non-trivial generalization of the MHKM theorem and suggests that there is a causal topology for FPD spacetimes which encodes manifold dimension and which is strictly finer than the Alexandrov topology. We show that such a causal topology does exist. We construct it using a convergence criterion based on sequences of 'chain intervals' which are the causal analogues of null geodesic segments. We show that when the region of strong causality violation satisfies a local achronality condition, this topology is equivalent to the manifold topology in an FPD spacetime.

  7. Molecular diagnosis of Anaplasmataceae organisms in dogs with clinical and microscopical signs of ehrlichiosis Diagnóstico molecular de agentes da família Anaplasmataceae em cães com sinais clínicos e microscópios de erliquiose

    Directory of Open Access Journals (Sweden)

    Ana Sílvia Dagnone

    2009-12-01

    Full Text Available Ehrlichioses are important emerging zoonotic tick-borne diseases that can affect both animals and humans. Clinical manifestations of ehrlichiosis caused by different members of Anaplasmataceae in dogs are similar to each other and to other diseases showing systemic manifestation. The observation of inclusions in white blood cells and in platelets cannot be used to confirm the Anaplasmataceae etiologic agent of the disease. In this work we assessed the presence of Anaplasmataceae agents in 51 dogs from two different cities (Jaboticabal and Campo Grande showing clinical and microscopical diagnosis of ehrlichiosis, by using molecular techniques. Anaplasmataceae DNA were amplified in 46/51 (90.2% of the blood samples; 22 (40% samples from Jaboticabal and 10 (18.2% from Campo Grande were positive for E. canis nPCR. Anaplasma platys DNA was amplified in 2 samples from Jaboticabal and in 11 from Campo Grande. Phylogenetic analysis of E. canis and A. platys DNA confirmed the infection agent and showed that PCR is the most reliable method to diagnose ehrlichial infection.Erliquioses são importantes enfermidades emergentes transmitidas por carrapatos que podem afetar os animais e o homem. Em cães, as manifestações clínicas da erliquiose causada por diferentes membros da Família Anaplasmataceae são similares entre si e entre outras enfermidades de manifestação sistêmica. A observação de inclusões em leucócitos e plaquetas não pode ser utilizada para diagnosticar o agente etiológico pertencente à Família Anaplasmataceae. O presente trabalho objetivou detectar, por meio de técnicas moleculares, a presença de agentes da Família Anaplasmataceae em 51 cães de duas diferentes cidades (Jaboticabal, SP e Campo Grande, MS apresentando sinais clínicos e microscópios sugestivos de erliquiose. DNA de agentes da Família Anaplasmataceae foi amplificado em 46/51 (90,2% das amostras de sangue; 22 (40% amostras de Jaboticabal e 10 (18,2% amostras

  8. Causality and stability of cosmic jets

    Science.gov (United States)

    Porth, Oliver; Komissarov, Serguei S.

    2015-09-01

    In stark contrast to their laboratory and terrestrial counterparts, cosmic jets appear to be very stable. They are able to penetrate vast spaces, which exceed by up to a billion times the size of their central engines. We propose that the reason behind this remarkable property is the loss of causal connectivity across these jets, caused by their rapid expansion in response to fast decline of external pressure with the distance from the `jet engine'. In atmospheres with power-law pressure distribution, pext ∝ z-κ, the total loss of causal connectivity occurs, when κ > 2 - the steepness which is expected to be quite common for many astrophysical environments. This conclusion does not seem to depend on the physical nature of jets - it applies both to relativistic and non-relativistic flows, both magnetically dominated and unmagnetized jets. In order to verify it, we have carried out numerical simulations of moderately magnetized and moderately relativistic jets. The results give strong support to our hypothesis and provide with valuable insights. In particular, we find that the z-pinched inner cores of magnetic jets expand slower than their envelopes and become susceptible to instabilities even when the whole jet is stable. This may result in local dissipation and emission without global disintegration of the flow. Cosmic jets may become globally unstable when they enter flat sections of external atmospheres. We propose that the Fanaroff-Riley (FR) morphological division of extragalactic radio sources into two classes is related to this issue. In particular, we argue that the low power FR-I jets become reconfined, causally connected and globally unstable on the scale of galactic X-ray coronas, whereas more powerful FR-II jets reconfine much further out, already on the scale of radio lobes and remain largely intact until they terminate at hotspots. Using this idea, we derived the relationship between the critical jet power and the optical luminosity of the host

  9. Quantum causality, stochastics, trajectories and information

    International Nuclear Information System (INIS)

    A history of the discovery of 'new' quantum mechanics and the paradoxes of its probabilistic interpretation are briefly reviewed from the modern point of view of quantum probability and information. Modern quantum theory, which has been developed during the last 20 years for the treatment of quantum open systems including quantum noise, decoherence, quantum diffusions and spontaneous jumps occurring under continuous in time observation, is not yet a part of the standard curriculum of quantum physics. It is argued that the conventional formalism of quantum mechanics is insufficient for the description of quantum events, such as spontaneous decays say, and the new experimental phenomena related to individual quantum measurements, but they have all received an adequate mathematical treatment in quantum stochastics of open systems. Moreover, the only reasonable probabilistic interpretation of quantum mechanics put forward by Max Born was, in fact, in irreconcilable contradiction with traditional mechanical reality and causality. This led to numerous quantum paradoxes, some of them due to the great inventors of quantum theory such as Einstein and Schroedinger. They are reconsidered in this paper from the modern point of view of quantum stochastics and information. The development of quantum measurement theory, initiated by von Neumann, indicated a possibility for resolution of this interpretational crisis by divorcing the algebra of the dynamical generators and the algebra of the actual observables, or Bell's beables. It is shown that within this approach quantum causality can be rehabilitated in the form of a superselection rule for compatibility of the actual histories with the potential future. This rule, together with the self-compatibility of the measurements ensuring the consistency of the histories, is called the nondemolition, or causality principle in modern quantum theory. The application of this rule in the form of dynamical commutation relations leads to the

  10. Shear bond strength after dentin bleaching with 10% carbamide peroxide agents Resistência ao cisalhamento da dentina após clareamento com peróxido de carbamida a 10%

    OpenAIRE

    Roberta Tarkany Basting; Patrícia Moreira de Freitas; Luiz André Freire Pimenta; Mônica Campos Serra

    2004-01-01

    This in vitro study evaluated the shear bond strength (SBS) of dentin treated with two 10% carbamide peroxide bleaching agents 15 days after bleaching and storage in artificial saliva. Dentin fragments were randomly divided into 3 groups (n = 20) for the treatment with the two different bleaching agents (Rembrandt 10% or Opalescence 10%) or with a placebo agent, applied to the tooth surface for 8 hours a day. During the remaining time, the specimens were stored in artificial saliva. After 42 ...

  11. Causality and hyperbolicity of Lovelock theories

    International Nuclear Information System (INIS)

    In Lovelock theories, gravity can travel faster or slower than light. The causal structure is determined by the characteristic hypersurfaces. We generalize a recent result of Izumi to prove that any Killing horizon is a characteristic hypersurface for all gravitational degrees of freedom of a Lovelock theory. Hence gravitational signals cannot escape from the region inside such a horizon. We investigate the hyperbolicity of Lovelock theories by determining the characteristic hypersurfaces for various backgrounds. First we consider Ricci flat type N spacetimes. We show that characteristic hypersurfaces are generically all non-null and that Lovelock theories are hyperbolic in any such spacetime. Next we consider static, maximally symmetric black hole solutions of Lovelock theories. Again, characteristic surfaces are generically non-null. For some small black holes, hyperbolicity is violated near the horizon. This implies that the stability of such black holes is not a well-posed problem. (paper)

  12. On the Causal Set-Continuum Correspondence

    CERN Document Server

    Saravani, Mehdi

    2014-01-01

    We present two results which concern certain aspects of the question: when is a causal set well approximated by a Lorentzian manifold? The first result is a theorem which shows that the number-volume correspondence, if required to hold even for arbitrarily small regions, is best realized via Poisson sprinkling. The second result concerns a family of lattices in $1+1$ dimensional Minkowski space, known as Lorentzian lattices, which we show provide a much better number-volume correspondence than Poisson sprinkling for large volumes. We argue, however, that this feature should not persist in higher dimensions. We conclude by conjecturing a form of the aforementioned theorem that holds under weaker assumptions, namely that Poisson sprinkling provides the best number-volume correspondence in $3+1$ dimensions for spacetime regions with macroscopically large volumes.

  13. Wiretap Channel with Causal State Information

    CERN Document Server

    Chia, Yeow-Khiang

    2010-01-01

    A lower bound on the secrecy capacity of the wiretap channel with state information available causally at both the encoder and decoder is established. The lower bound is shown to be strictly larger than that for the noncausal case by Liu and Chen. Achievability is proved using block Markov coding, Shannon strategy, and key generation from common state information. The state sequence available at the end of each block is used to generate a key, which is used to enhance the transmission rate of the confidential message in the following block. An upper bound on the secrecy capacity when the state is available noncausally at the encoder and decoder is established and is shown to coincide with the lower bound for several classes of wiretap channels with state.

  14. Causality Constraints in Conformal Field Theory

    CERN Document Server

    CERN. Geneva

    2015-01-01

    Causality places nontrivial constraints on QFT in Lorentzian signature, for example fixing the signs of certain terms in the low energy Lagrangian. In d-dimensional conformal field theory, we show how such constraints are encoded in crossing symmetry of Euclidean correlators, and derive analogous constraints directly from the conformal bootstrap (analytically). The bootstrap setup is a Lorentzian four-point function corresponding to propagation through a shockwave. Crossing symmetry fixes the signs of certain log terms that appear in the conformal block expansion, which constrains the interactions of low-lying operators. As an application, we use the bootstrap to rederive the well known sign constraint on the (∂φ)4 coupling in effective field theory, from a dual CFT. We also find constraints on theories with higher spin conserved currents. Our analysis is restricted to scalar correlators, but we argue that similar methods should also impose nontrivial constraints on the interactions of spinni...

  15. Equity Theory Ratios as Causal Schemas

    Science.gov (United States)

    Arvanitis, Alexios; Hantzi, Alexandra

    2016-01-01

    Equity theory approaches justice evaluations based on ratios of exchange inputs to exchange outcomes. Situations are evaluated as just if ratios are equal and unjust if unequal. We suggest that equity ratios serve a more fundamental cognitive function than the evaluation of justice. More particularly, we propose that they serve as causal schemas for exchange outcomes, that is, they assist in determining whether certain outcomes are caused by inputs of other people in the context of an exchange process. Equality or inequality of ratios in this sense points to an exchange process. Indeed, Study 1 shows that different exchange situations, such as disproportional or balanced proportional situations, create perceptions of give-and-take on the basis of equity ratios. Study 2 shows that perceptions of justice are based more on communicatively accepted rules of interaction than equity-based evaluations, thereby offering a distinction between an attribution and an evaluation cognitive process for exchange outcomes.

  16. Exploring Torus Universes in Causal Dynamical Triangulations

    CERN Document Server

    Budd, T G

    2013-01-01

    Motivated by the search for new observables in nonperturbative quantum gravity, we consider Causal Dynamical Triangulations (CDT) in 2+1 dimensions with the spatial topology of a torus. This system is of particular interest, because one can study not only the global scale factor, but also global shape variables in the presence of arbitrary quantum fluctuations of the geometry. Our initial investigation focusses on the dynamics of the scale factor and uncovers a qualitatively new behaviour, which leads us to investigate a novel type of boundary conditions for the path integral. Comparing large-scale features of the emergent quantum geometry in numerical simulations with a classical minisuperspace formulation, we find partial agreement. By measuring the correlation matrix of volume fluctuations we succeed in reconstructing the effective action for the scale factor directly from the simulation data. Apart from setting the stage for the analysis of shape dynamics on the torus, the new set-up highlights the role o...

  17. Causality constraints in conformal field theory

    Science.gov (United States)

    Hartman, Thomas; Jain, Sachin; Kundu, Sandipan

    2016-05-01

    Causality places nontrivial constraints on QFT in Lorentzian signature, for example fixing the signs of certain terms in the low energy Lagrangian. In d dimensional conformal field theory, we show how such constraints are encoded in crossing symmetry of Euclidean correlators, and derive analogous constraints directly from the conformal bootstrap (analytically). The bootstrap setup is a Lorentzian four-point function corresponding to propagation through a shockwave. Crossing symmetry fixes the signs of certain log terms that appear in the conformal block expansion, which constrains the interactions of low-lying operators. As an application, we use the bootstrap to rederive the well known sign constraint on the (∂ ϕ)4 coupling in effective field theory, from a dual CFT. We also find constraints on theories with higher spin conserved currents. Our analysis is restricted to scalar correlators, but we argue that similar methods should also impose nontrivial constraints on the interactions of spinning operators.

  18. A study in cosmology and causal thermodynamics

    International Nuclear Information System (INIS)

    The especial relativity of thermodynamic theories for reversible and irreversible processes in continuous medium is studied. The formalism referring to equilibrium and non-equilibrium configurations, and theories which includes the presence of gravitational fields are discussed. The nebular model in contraction with dissipative processes identified by heat flux and volumetric viscosity is thermodymically analysed. This model is presented by a plane conformal metric. The temperature, pressure, entropy and entropy production within thermodynamic formalism which adopts the hypothesis of local equilibrium, is calculated. The same analysis is carried out considering a causal thermodynamics, which establishes a local entropy of non-equilibrium. Possible homogeneous and isotropic cosmological models, considering the new phenomenological equation for volumetric viscosity deriving from cause thermodynamics are investigated. The found out models have plane spatial section (K=0) and some ones do not have singularities. The energy conditions are verified and the entropy production for physically reasobable models are calculated. (M.C.K.)

  19. Causality and local determinism versus quantum nonlocality

    CERN Document Server

    Kupczynski, Marian

    2013-01-01

    The entanglement and the violation of Bell and CHSH inequalities in spin polarization correlation experiments (SPCE) is considered to be one of the biggest mysteries of Nature and is called quantum nonlocality. In this paper we show once again that this conclusion is based on imprecise terminology and on the lack of understanding of probabilistic models used in various proofs of Bell and CHSH theorems. These models are inconsistent with experimental protocols used in SPCE. This is the only reason why Bell and CHSH inequalities are violated. A probabilistic non-signalling description of SPCE, consistent with quantum predictions, is possible and it depends explicitly on the context of each experiment. It is also deterministic in the sense that the outcome is determined by supplementary local parameters describing both a physical signals and measuring instruments. The existence of such description gives additional arguments that quantum theory is emergent from some more detailed theory respecting causality and l...

  20. Causality Constraints in Conformal Field Theory

    CERN Document Server

    Hartman, Thomas; Kundu, Sandipan

    2015-01-01

    Causality places nontrivial constraints on QFT in Lorentzian signature, for example fixing the signs of certain terms in the low energy Lagrangian. In d-dimensional conformal field theory, we show how such constraints are encoded in crossing symmetry of Euclidean correlators, and derive analogous constraints directly from the conformal bootstrap (analytically). The bootstrap setup is a Lorentzian four-point function corresponding to propagation through a shockwave. Crossing symmetry fixes the signs of certain log terms that appear in the conformal block expansion, which constrains the interactions of low-lying operators. As an application, we use the bootstrap to rederive the well known sign constraint on the $(\\partial\\phi)^4$ coupling in effective field theory, from a dual CFT. We also find constraints on theories with higher spin conserved currents. Our analysis is restricted to scalar correlators, but we argue that similar methods should also impose nontrivial constraints on the interactions of spinning o...

  1. The balanced survivor average causal effect.

    Science.gov (United States)

    Greene, Tom; Joffe, Marshall; Hu, Bo; Li, Liang; Boucher, Ken

    2013-01-01

    Statistical analysis of longitudinal outcomes is often complicated by the absence of observable values in patients who die prior to their scheduled measurement. In such cases, the longitudinal data are said to be "truncated by death" to emphasize that the longitudinal measurements are not simply missing, but are undefined after death. Recently, the truncation by death problem has been investigated using the framework of principal stratification to define the target estimand as the survivor average causal effect (SACE), which in the context of a two-group randomized clinical trial is the mean difference in the longitudinal outcome between the treatment and control groups for the principal stratum of always-survivors. The SACE is not identified without untestable assumptions. These assumptions have often been formulated in terms of a monotonicity constraint requiring that the treatment does not reduce survival in any patient, in conjunction with assumed values for mean differences in the longitudinal outcome between certain principal strata. In this paper, we introduce an alternative estimand, the balanced-SACE, which is defined as the average causal effect on the longitudinal outcome in a particular subset of the always-survivors that is balanced with respect to the potential survival times under the treatment and control. We propose a simple estimator of the balanced-SACE that compares the longitudinal outcomes between equivalent fractions of the longest surviving patients between the treatment and control groups and does not require a monotonicity assumption. We provide expressions for the large sample bias of the estimator, along with sensitivity analyses and strategies to minimize this bias. We consider statistical inference under a bootstrap resampling procedure. PMID:23658214

  2. Recursive partitioning for heterogeneous causal effects.

    Science.gov (United States)

    Athey, Susan; Imbens, Guido

    2016-07-01

    In this paper we propose methods for estimating heterogeneity in causal effects in experimental and observational studies and for conducting hypothesis tests about the magnitude of differences in treatment effects across subsets of the population. We provide a data-driven approach to partition the data into subpopulations that differ in the magnitude of their treatment effects. The approach enables the construction of valid confidence intervals for treatment effects, even with many covariates relative to the sample size, and without "sparsity" assumptions. We propose an "honest" approach to estimation, whereby one sample is used to construct the partition and another to estimate treatment effects for each subpopulation. Our approach builds on regression tree methods, modified to optimize for goodness of fit in treatment effects and to account for honest estimation. Our model selection criterion anticipates that bias will be eliminated by honest estimation and also accounts for the effect of making additional splits on the variance of treatment effect estimates within each subpopulation. We address the challenge that the "ground truth" for a causal effect is not observed for any individual unit, so that standard approaches to cross-validation must be modified. Through a simulation study, we show that for our preferred method honest estimation results in nominal coverage for 90% confidence intervals, whereas coverage ranges between 74% and 84% for nonhonest approaches. Honest estimation requires estimating the model with a smaller sample size; the cost in terms of mean squared error of treatment effects for our preferred method ranges between 7-22%. PMID:27382149

  3. Agent, autonomous

    OpenAIRE

    Luciani, Annie

    2007-01-01

    The expression autonomous agents, widely used in virtual reality, computer graphics, artificial intelligence and artificial life, corresponds to the simulation of autonomous creatures, virtual (i.e. totally computed by a program), or embodied in a physical envelope, as done in autonomous robots.

  4. Severidade da podridão-verde em inhames e especialização fisiológica em Penicillium sclerotigenum Severity of green rot in yellow and water yams and the physiological specialization of Penicillium sclerotigenum

    OpenAIRE

    Idjane S. Oliveira; Edna Dora. M. N. Luz; José Luiz Bezerra; Romero M. de Moura; Gustavo R. C. Torres; Leonor C. Maia

    2006-01-01

    Estudaram-se as reações do inhame Dioscorea alata cv. São Tomé e D. cayennensis cv. Da Costa em relação à severidade da podridão-verde, causada pelo fungo Penicillium sclerotigenum. Ao mesmo tempo, foi pesquisada à ocorrência de especialização fisiológica do agente causal, em relação à patogenicidade, nas mencionadas espécies de inhame. Para complementar esse estudo, analisou-se, in vitro, o crescimento micelial de P. sclerotigenum em três meios de cultura semi-sintéticos, sendo dois à base d...

  5. World oil and agricultural commodity prices: Evidence from nonlinear causality

    International Nuclear Information System (INIS)

    The increasing co-movements between the world oil and agricultural commodity prices have renewed interest in determining price transmission from oil prices to those of agricultural commodities. This study extends the literature on the oil-agricultural commodity prices nexus, which particularly concentrates on nonlinear causal relationships between the world oil and three key agricultural commodity prices (corn, soybeans, and wheat). To this end, the linear causality approach of Toda-Yamamoto and the nonparametric causality method of Diks-Panchenko are applied to the weekly data spanning from 1994 to 2010. The linear causality analysis indicates that the oil prices and the agricultural commodity prices do not influence each other, which supports evidence on the neutrality hypothesis. In contrast, the nonlinear causality analysis shows that: (i) there are nonlinear feedbacks between the oil and the agricultural prices, and (ii) there is a persistent unidirectional nonlinear causality running from the oil prices to the corn and to the soybeans prices. The findings from the nonlinear causality analysis therefore provide clues for better understanding the recent dynamics of the agricultural commodity prices and some policy implications for policy makers, farmers, and global investors. This study also suggests the directions for future studies. - Research highlights: → This study determines the price transmission mechanisms between the world oil and three key agricultural commodity prices (corn, soybeans, and wheat). → The linear and nonlinear cointegration and causality methods are carried out. → The linear causality analysis supports evidence on the neutrality hypothesis. → The nonlinear causality analysis shows that there is a persistent unidirectional causality from the oil prices to the corn and to the soybeans prices.

  6. The Dynamic Causal Relationship between Electricity Consumption and Economic Growth in Ghana: A Trivariate Causality Model

    Directory of Open Access Journals (Sweden)

    Bernard N. Iyke

    2014-06-01

    Full Text Available This paper examines the dynamic causal relationship between electricity consumption and economic growth in Ghana within a trivariate ARDL framework, for the period 1971–2012.The paper obviates the variable omission bias, and the use of cross-sectional techniques that characterise most existing studies. The results show that there is a distinct causal flow from economic growth to electricity consumption: both in the short run and in the long run. This finding supports the growth-led electricity consumption hypothesis, as documented in the literature. The paper urges policymakers in Ghana to resort to alternative sources of electric power generation, in order to reduce any future pressures on the current sources of electricity production. Appropriate monetary policies must also be put in place, in order to accommodate potential inflation hikes stemming from excessive demands for electricity in the near future.

  7. Effect of a New Prokinetic Agent DA-9701 Formulated with Corydalis Tuber and Pharbitidis Semen on Cytochrome P450 and UDP-Glucuronosyltransferase Enzyme Activities in Human Liver Microsomes

    Directory of Open Access Journals (Sweden)

    Hye Young Ji

    2012-01-01

    Full Text Available DA-9701 is a new botanical drug composed of the extracts of Corydalis tuber and Pharbitidis semen, and it is used as an oral therapy for the treatment of functional dyspepsia in Korea. The inhibitory potentials of DA-9701 and its component herbs, Corydalis tuber and Pharbitidis semen, on the activities of seven major human cytochrome P450 (CYP enzymes and four UDP-glucuronosyltransferase (UGT enzymes in human liver microsomes were investigated using liquid chromatography-tandem mass spectrometry. DA-9701 and Corydalis tuber extract slightly inhibited UGT1A1-mediated etoposide glucuronidation, with 50% inhibitory concentration (IC50 values of 188 and 290 μg/mL, respectively. DA-9701 inhibited CYP2D6-catalyzed bufuralol 1′-hydroxylation with an inhibition constant (Ki value of 6.3 μg/mL in a noncompetitive manner. Corydalis tuber extract competitively inhibited CYP2D6-mediated bufuralol 1′-hydroxylation, with a Ki value of 3.7 μg/mL, whereas Pharbitidis semen extract showed no inhibition. The volume in which the dose could be diluted to generate an IC50 equivalent concentration (volume per dose index value of DA-9701 for inhibition of CYP2D6 activity was 1.16 L/dose, indicating that DA-9701 may not be a potent CYP2D6 inhibitor. Further clinical studies are warranted to evaluate the in vivo extent of the observed in vitro interactions.

  8. Manifest Variable Granger Causality Models for Developmental Research: A Taxonomy

    Science.gov (United States)

    von Eye, Alexander; Wiedermann, Wolfgang

    2015-01-01

    Granger models are popular when it comes to testing hypotheses that relate series of measures causally to each other. In this article, we propose a taxonomy of Granger causality models. The taxonomy results from crossing the four variables Order of Lag, Type of (Contemporaneous) Effect, Direction of Effect, and Segment of Dependent Series…

  9. Child Care Subsidy Use and Child Development: Potential Causal Mechanisms

    Science.gov (United States)

    Hawkinson, Laura E.

    2011-01-01

    Research using an experimental design is needed to provide firm causal evidence on the impacts of child care subsidy use on child development, and on underlying causal mechanisms since subsidies can affect child development only indirectly via changes they cause in children's early experiences. However, before costly experimental research is…

  10. Causal Propagators for the Second Order Wilson Loop

    OpenAIRE

    Pimentel, B. M.; Tomazelli, J. L.

    1996-01-01

    We evaluate the Wilson loop at second order in general non-covariant gauges by means of the causal principal-value prescription for the gauge- dependent poles in the gauge-boson propagator and show that the result agrees with the usual causal prescriptions.

  11. Evidence for Deductive Reasoning in Blocking of Causal Judgments

    Science.gov (United States)

    Mitchell, C.J.; Lovibond, P.F.; Condoleon, M.

    2005-01-01

    We have recently demonstrated that pre-training of additivity (the outcome of two causal cues is larger than one causal cue) greatly enhances blocking. This manipulation could work by removing a ceiling effect on the outcome, as proposed by Cheng (1997). Alternatively, it could remove the logical ambiguity associated with blocking under…

  12. Time Symmetric Quantum Mechanics and Causal Classical Physics

    CERN Document Server

    Bopp, Fritz W

    2016-01-01

    A two boundary quantum mechanics without time ordered causal structure is advocated as consistent theory. The apparent causal structure of usual "near future" macroscopic phenomena is attributed to a cosmological asymmetry and to rules governing the transition between microscopic to macroscopic observations. Our interest is a heuristic understanding of the resulting macroscopic physics.

  13. Cause and Event: Supporting Causal Claims through Logistic Models

    Science.gov (United States)

    O'Connell, Ann A.; Gray, DeLeon L.

    2011-01-01

    Efforts to identify and support credible causal claims have received intense interest in the research community, particularly over the past few decades. In this paper, we focus on the use of statistical procedures designed to support causal claims for a treatment or intervention when the response variable of interest is dichotomous. We identify…

  14. The causal boundary and its relations with the conformal boundary

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, J, E-mail: jherrera@agt.cie.uma.e [Departamento de Algebra, GeometrIa y TopologIa, Facultad de Ciencias, Universidad de Malaga, Campus Teatinos, 29071 Malaga (Spain)

    2010-05-01

    Our aim in this note is to present the results (obtained in [2]) which ensure that, under certain regularity conditions, the conformal boundary becomes equal to the causal boundary, not only as a point set, but in a topological and chronological level. In particular, under these conditions the conformal boundary becomes a powerful tool to compute the causal one.

  15. Causal Discourse Analyzer: Improving Automated Feedback on Academic ESL Writing

    Science.gov (United States)

    Chukharev-Hudilainen, Evgeny; Saricaoglu, Aysel

    2016-01-01

    Expressing causal relations plays a central role in academic writing. While it is important that writing instructors assess and provide feedback on learners' causal discourse, it could be a very time-consuming task. In this respect, automated writing evaluation (AWE) tools may be helpful. However, to date, there have been no AWE tools capable of…

  16. Thinking Fast and Slow about Causality: Response to Palinkas

    Science.gov (United States)

    Marsh, Jeanne C.

    2014-01-01

    Larry Palinkas advances the developing science of social work by providing an explanation of how social science research methods, both qualitative and quantitative, can improve our capacity to draw casual inferences. Understanding causal relations and making causal inferences--with the promise of being able to predict and control outcomes--is…

  17. From Blickets to Synapses: Inferring Temporal Causal Networks by Observation

    Science.gov (United States)

    Fernando, Chrisantha

    2013-01-01

    How do human infants learn the causal dependencies between events? Evidence suggests that this remarkable feat can be achieved by observation of only a handful of examples. Many computational models have been produced to explain how infants perform causal inference without explicit teaching about statistics or the scientific method. Here, we…

  18. Temporal and Causal Reasoning in Deaf and Hearing Novice Readers

    Science.gov (United States)

    Sullivan, Susan; Oakhill, Jane; Arfé, Barbara; Boureux, Magali

    2014-01-01

    Temporal and causal information in text are crucial in helping the reader form a coherent representation of a narrative. Deaf novice readers are generally poor at processing linguistic markers of causal/temporal information (i.e., connectives), but what is unclear is whether this is indicative of a more general deficit in reasoning about…

  19. Quantum objects as elementary units of causality and locality

    CERN Document Server

    Diel, Hans H

    2016-01-01

    The author's attempt to construct a local causal model of quantum theory (QT) that includes quantum field theory (QFT) resulted in the identification of "quantum objects" as the elementary units of causality and locality. Quantum objects are collections of particles (including single particles) whose collective dynamics and measurement results can only be described by the laws of QT and QFT. Local causal models of quantum objects' internal dynamics are not possible if a locality is understood as a space-point locality. Within quantum objects, state transitions may occur which instantly affect the whole quantum object. The identification of quantum objects as the elementary units of causality and locality has two primary implications for a causal model of quantum objects: (1) quantum objects run autonomously with system-state update frequencies based on their local proper times and with either no or minimal dependency on external parameters. (2) The laws of physics that describe global (but relativistic) inter...

  20. A causal net approach to relativistic quantum mechanics

    Science.gov (United States)

    Bateson, R. D.

    2012-05-01

    In this paper we discuss a causal network approach to describing relativistic quantum mechanics. Each vertex on the causal net represents a possible point event or particle observation. By constructing the simplest causal net based on Reichenbach-like conjunctive forks in proper time we can exactly derive the 1+1 dimension Dirac equation for a relativistic fermion and correctly model quantum mechanical statistics. Symmetries of the net provide various quantum mechanical effects such as quantum uncertainty and wavefunction, phase, spin, negative energy states and the effect of a potential. The causal net can be embedded in 3+1 dimensions and is consistent with the conventional Dirac equation. In the low velocity limit the causal net approximates to the Schrodinger equation and Pauli equation for an electromagnetic field. Extending to different momentum states the net is compatible with the Feynman path integral approach to quantum mechanics that allows calculation of well known quantum phenomena such as diffraction.