Nutritional value of silk flower hay for lambs Valor nutritional do feno de flor-de-seda para cordeiros

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Aderbal Marcos de Azevêdo Silva

2010-12-01

nutrientes e aumentou a conversão alimentar e o coeficiente de digestibilidade de todos os nutrientes. O balanço de nitrogênio foi semelhante em todos os níveis de feno de flor-de-seda, embora tenha havido tendência de redução na retenção do nitrogênio nos níveis 66 e 100% de feno de flor-de-seda. Nos níveis 0 e 33% de feno de flor-de-seda na dieta, a ingestão de matéria seca (170 e 180 g/dia, o ganho médio diário de peso (84 e 89 g/kg0,75 e a conversão alimentar (4,99 e 5,02 foram satisfatórios. O feno de flor-de-seda pode representar até 16,5% da ingestão total ou 33% do volumoso da dieta de cordeiros.

CRESCIMENTO DA PARTE AÉREA DE MUDAS DE COUVE-FLOR PRODUZIDAS EM DIFERENTES SUBSTRATOS EM SISTEMA AGROECOLÓGICO

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Julio Cesar Gradice Saluci

2017-04-01

Full Text Available A agricultura exerce grande expressividade no desenvolvimento social, político e econômico do Brasil. Contudo existe constate crescimento na procura e exigência por alimentos mais saudáveis, que podem ser produzidos com técnicas da agroecologia. Objetivou-se com este trabalho avaliar diferentes substratos na produção de mudas de couve-flor. O experimento foi em DIC, no esquema fatorial (4x4 avaliando 7 plantas em cada tratamento na fase final de mudas. Os resultados encontrados para a parte aérea, demostraram desenvolvimento satisfatório para a cultura nos substratos orgânicos, em relação ao comercial, sendo que foi observado superioridade das variáveis quando utilizou-se o vermicomposto como substrato, independente das concentrações usadas, entretanto não houve diferença entre as concentrações usadas para esse substrato. Os substratos orgânicos proporcionaram boa produção. Dentre estes substratos destacou-se o vermicomposto.

Efeito de Trilhas sobre Artrópodes de Serrapilheira no Parque Nacional da Tijuca, RJ

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Felipe Drummond-Alves

2017-07-01

Full Text Available RESUMO Foi analisado o efeito de trilhas sobre a comunidade de artrópodes de serrapilheira em duas trilhas do Parque Nacional da Tijuca. Amostras de serrapilheira foram coletadas em duas cotas altitudinais (650 e 850 m anm e em três classes de distância (0, 5 e 10 m. Os artrópodes foram identificados ao nível de ordem. Foram amostrados 4.491 indivíduos de 19 taxa, sendo Orthoptera a mais frequente. Foram encontradas diferenças significativas no número de táxons entre trilhas, possivelmente como resposta a um efeito causal da estrutura e da composição florística das trilhas e das cotas. A trilha que apresentou os maiores valores de riqueza foi a do Bico do Papagaio, diferindo da trilha do Pico da Tijuca. Concluiu-se que as diferenças encontradas podem estar relacionadas com o grau de perturbação diferenciado que as duas trilhas sofrem. No entanto, análises mais detalhadas poderão tornar os resultados mais claros.

Composição florística do componente arbóreo de um trecho de Floresta Atlântica na Área de Proteção Ambiental da Serra da Capoeira Grande, Rio de Janeiro, RJ, Brasil Floristic survey of the tree layer in an area of Atlantic Rainforest in Serra da Capoeira Grande Environmental Protection Area, Rio de Janeiro State, Brazil

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Gustavo Luna Peixoto

2004-03-01

Full Text Available A Área de Proteção Ambiental (APA da Serra da Capoeira Grande (22º59'03"S e 43º38'59"W tem área total de 80ha e é um dos últimos remanescentes florestais com pau-brasil (Caesalpinia echinata Lam. no município do Rio de Janeiro. Além disso, ocorrem na área outras três espécies ameaçadas de extinção: Cariniana ianeirensis R. Knuth, Acosmium lentiscifolium Spreng. e Machaerium incorruptible (Vell. Fr. All. ex Benth. O levantamento fitossociológico foi realizado por meio do método dos quadrantes, tendo sido alocados 200 pontos e tendo-se como critério de inclusão 15cm de circunferência do tronco a 1,30m de altura do solo. A composição florística é o resultado desta amostragem acrescida de coletas feitas durante caminhadas no fragmento, totalizando 29 famílias, 58 gêneros e 69 espécies. As famílias que apresentaram maior número de espécies foram: Leguminosae (13, Myrtaceae (6, Euphorbiaceae (5, Bignoniaceae, Bombacaceae, Celastraceae, Flacourtiaceae, Moraceae, Rubiaceae e Solanaceae (3. Analisando a similaridade florística entre a APA da Serra da Capoeira Grande e outras 18 áreas florestais do Rio de Janeiro, observou-se maior identidade florística entre a área estudada e florestas de baixada localizadas próximas ao mar. Todas as florestas reuniram-se com um baixo nível de similaridade, refletindo a diversidade florística das florestas do Rio de Janeiro.The 80-hectare site (22º59'03"S and 43º38'59"W, is one of the last forest remnants in Rio de Janeiro municipality, where brazilwood (Caesalpinia echinata Lam. occurs naturally. Furthermore, three other endangered species occur in this area: Cariniana ianeirensis R. Knuth, Acosmium lentiscifolium Spreng., and Machaerium incorruptible (Vell. Fr. All. ex Benth. Trees were sampled according to the point-centered-quarter method. The inclusion criteria was PBH >15cm; a total of 200 points were surveyed. The floristic composition was comprised of the sampled

Estudo do sistema de reprodução da fava-d'anta (Dimorphandra mollis Benth.

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A.D.R. Mendes

2013-01-01

Full Text Available Entre as plantas nativas de uso medicinal do Cerrado brasileiro encontra-se a fava-d'anta (Dimorphandra mollis Benth com alto potencial econômico por possuir inúmeras potencialidades medicinais e fitoquímicas. A indústria extrai dos frutos os princípios ativos rutina, quercetina, e ramnose, dentre outros, usados na fabricação de medicamentos e cosméticos, principalmente no exterior. O conhecimento do sistema reprodutivo da espécie é fundamental para sua conservação e manejo. O presente trabalho objetivou determinar as características morfométricas das flores e caracterizar o sistema reprodutivo da D. mollis em área de Cerrado inalterada antropomorficamente, no município de Olhos D'água - MG. Para as características morfométricas, diâmetro da flor, comprimento da flor, do ovário, e da antera, foram utilizadas cinco flores em pré-antese. Para a determinação do sistema reprodutivo utilizou-se a razão pólen:óvulo (P:O, em 40 flores. As flores da D. mollis apresentaram comprimento da flor de 3,00 mm, diâmetro da flor de 2,00 mm, comprimento do óvulo de 2,60 mm, comprimento da antera de 1,57 mm, e o número de óvulos e de anteras foram 20 e 5,8, respectivamente. A razão P:O foi 765,030, sendo que esse índice não é afetado pelas características morfométricas. O sistema reprodutivo da D. mollis foi classificado como alógama facultativa.

E uma rosa se abre: a guerra e a flor na poesia de Drummond

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Valéria Daiane Soares Rodrigues

2013-08-01

Full Text Available Carlos Drummond de Andrade, em A Rosa do Povo (1945 articula, por meio da palavra e da criação de um “eu” lírico habitante de um mundo em guerra, a construção de uma imagem, imbuída de teor histórico, do Brasil dos anos finais da 2ª guerra mundial. Os versos traduzem a experiência do Drummond gauche, angustiado pelos problemas do seu tempo, em que a individualidade advinda da fragmentação do homem moderno é marca do conflito entre o “eu” lírico e o mundo. O poeta descreve de forma melancólica a degeneração das coisas e dos homens, em meio à consciência paralisante e a falta de perspectivas. A força que emerge do símbolo da rosa respalda o acento poético do Itabirano: a destruição dos valores provocados pela morte e pelo derramar de sangue contrasta com o brotar da flor no asfalto.  Do chão forrado de cadáveres, emerge uma rosa, numa representação da resistência humana.

JOHN SEARLE SOBRE A IDENTIDADE E A EFICÁCIA CAUSAL DA CONSCIÊNCIA

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Tárik de Athayde Prata

2010-01-01

Full Text Available O texto discute os problemas em que se envolve o naturalismo biológico deJohn Searle ao defender (a a eficácia causal da consciência, (b a identidade dascapacidades causais da consciência e das capacidades causais dos processos cerebrais e(c a irredutibilidade ontológica da consciência. Essas três teses parecem implicar que aconsciência é e não é idêntica à atividade cerebral. Uma solução poderia ser encontradase o autor discutisse mais cuidadosamente a noção de identidade.

Proteins involved in flor yeast carbon metabolism under biofilm formation conditions.

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Moreno-García, Jaime; García-Martínez, Teresa; Moreno, Juan; Mauricio, Juan Carlos

2015-04-01

A lack of sugars during the production of biologically aged wines after fermentation of grape must causes flor yeasts to metabolize other carbon molecules formed during fermentation (ethanol and glycerol, mainly). In this work, a proteome analysis involving OFFGEL fractionation prior to LC/MS detection was used to elucidate the carbon metabolism of a flor yeast strain under biofilm formation conditions (BFC). The results were compared with those obtained under non-biofilm formation conditions (NBFC). Proteins associated to processes such as non-fermentable carbon uptake, the glyoxylate and TCA cycles, cellular respiration and inositol metabolism were detected at higher concentrations under BFC than under the reference conditions (NBFC). This study constitutes the first attempt at identifying the flor yeast proteins responsible for the peculiar sensory profile of biologically aged wines. A better metabolic knowledge of flor yeasts might facilitate the development of effective strategies for improved production of these special wines. Copyright © 2014 Elsevier Ltd. All rights reserved.

EFEITO DE DIFERENTES TEMPOS DE COZIMENTO NOS TEORES DE FIBRAS ALIMENTARES EM FOLHAS DE BRÓCOLIS, COUVE-FLOR E COUVE (BRASSICA OLERACEA L.

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Mônica Alessandra Teixeira dos SANTOS

2009-07-01

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Foram determinados os teores de fibras alimentares (FDA, FDN, lignina e pectinas das folhas de brócolis e couve-flor e comparados aos teores encontrados nas tradicionais folhas de couve. Os materiais estudados foram cultivados no município de Ijaci MG, com o objetivo da utilização integral dessas hortaliças como fonte alternativa de fibras. As folhas foram submetidas a cocção por seis diferentes tempos (0, 2, 4, 6, 8 e 10 minutos. Acompanhando o comportamento das diversas frações da fibra no material úmido e após secagem. Os resultados mostraram que as folhas de couve-flor e brócolis superaram a couve comum, que apresentou teores superiores apenas na fração FDA do material seco. Os resultados revelaram que as folhas das hortaliças analisadas podem ser consideradas como boas fontes de fibras insolúveis, mas não contribuem significativamente com a porção solúvel.

Gastronomia sensual: análise simbólica de A festa de Babette e Dona Flor e seus dois maridos = Sensual gastronomy: symbolic analysis of Babetes fiest and Dona Flor e seus dois maridos

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Rocha, Gilmar

2009-01-01

Full Text Available O texto apresenta uma análise simbólica sobre a representação do gênero feminino dramatizada nos filmes Dona Flor e seus dois maridos (1976 e A festa de Babette (1987. Ambientados em contextos socio-históricos diferentes, tais filmes podem ser vistos como “etnografias” que falam do imaginário religioso e do ethos cultural protestante na Dinamarca de fins do século 19 e do sincretismo afro-brasileiro da primeira metade do século 20. O ponto de vista da antropologia simbólica, alimentada pelas contribuições teóricas de Clifford Geertz, Marcel Mauss, Victor Turner e Roberto DaMatta, orienta a interpretação dos filmes a partir dos códigos culturais da culinária (comida, da corporalidade (sexualidade e da religiosidade (puritanismo e sincretismo. Destaca-se, nessas “etnografias fílmicas”, o modo como os sistemas da dádiva e da carnavalização que as estruturam convergem para um mesmo campo de significação. A estratégia metodológica adotada consiste em comparar os filmes tendo por base a estrutura conceitual dos “dramas sociais”

Bignoniaceae Juss. do Parque Estadual do Itacolomi, Minas Gerais, Brasil: florística, similaridade e distribuição geográfica

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Araújo, Ricardo de Souza

2008-01-01

Este trabalho consiste do levantamento florístico de Bignoniaceae do Parque Estadual do Itacolomi (PEI), Minas Gerais, da distribuição geográfica das espécies e da similaridade entre trilhas do PEI e entre outras áreas do Brasil. As coletas foram realizadas mensalmente em 15 trilhas pré- estabelecidas, sendo sete em campo rupestre e oito em Floresta Estacional Semidecídua, totalizando 15 expedições de agosto/2006 a outubro/2007. O material foi herborizado e incorporado ao acervo do Herbário V...

Conexões florísticas e funcionamento de comunidades arbóreas associadas à inselberg no domínio atlântico

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Paula, Eduardo de Paiva

2014-01-01

A presente dissertação encontra-se estruturada em dois artigos. No primeiro, objetivou-se, compreender as relações fitogeográficas de três comunidades arbóreas associadas a um inselberg,em Minas Gerais (Serra da Canoa), através da análise florística de 22 localidades/unidades florestais , em diferentes escalas geográficas do mesmo Estado, incluindo três comunidades arbóreas associadas a outro inselberg, em MG. Foram utilizadas duas técnicas de analise multivariada: Análise de correspondência ...

Estrutura e relações ambientais de grupos florísticos em fragmento de floresta estacional subtropical

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Suzane Bevilacqua Marcuzzo

2013-04-01

Full Text Available Este estudo teve por objetivos analisar a estrutura de grupos florísticos na vegetação arbórea-arbustiva de um trecho de encosta de Floresta Estacional Subtropical, no Parque Estadual Quarta Colônia, RS, e determinar fatores ambientais importantes na ocorrência das espécies, a fim de subsidiar programas de restauração de áreas degradadas como ecossistema de referência. Para isso, foi realizado estudo fitossociológico em 12 parcelas de 200 m² (10 x 20 m, distantes 20 m entre si, distribuídas sistematicamente em quatro faixas de 100 m entre si, seguindo gradiente de topografia. Em cada parcela foram realizadas a identificação e a medição da circunferência à altura do peito (CAP e da altura total dos indivíduos arbóreos e arbustivos, ou seja, com CAP > 15 cm, denominado componente arbóreo. Os dados do sub-bosque foram obtidos em parcelas circulares com raio de 1,78 m, instaladas no centro das parcelas de 10 x 20 m, medindo-se indivíduos com altura > 30 cm e CAP <15 cm. As variáveis ambientais foram compostas pela declividade, pela intensidade luminosa, pelas características químicas e textura do solo. Os dados foram analisados segundo a estrutura e diversidade da vegetação por meio da análise de agrupamento pelo método TWINSPAN (Two-way Indicator Species Analysis e da ordenação pelo método CCA (Análise de Correspondência Canônica. Foi identificada a formação de dois grupos florísticos. A composição de espécies de cada grupo pertence a diferentes estágios de sucessão natural, conforme histórico de uso agrícola, e, segundo suas características funcionais, podem ser indicadas para programas de restauração florestal.

Florística e classificação da regeneração natural em Floresta Ombrófila Mista na Floresta Nacional de São Francisco de Paula, RS.

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Igor da Silva Narvaes

2009-10-01

Full Text Available Normal 0 21 MicrosoftInternetExplorer4 Na floresta Ombrófila Mista, a regeneração natural é pouco estudada. No Rio Grande do Sul, em conseqüência da ação antrópica, essas florestas se encontram sob diferentes condições de alteração, em alguns casos formando fragmentos. O estudo teve como objetivo analisar a florística da regeneração natural e verificar a ocorrência de grupos florísticos de uma área onde não foram constatadas alterações intensas. A área com 1606,69 ha localiza-se na Floresta Nacional de São Francisco de Paula (entre 29° 23' e 29° 27' S; 50° 23' e 50° 25' W, no município de São Francisco de Paula, RS. No estudo, foram selecionadas seis parcelas permanentes de crescimento do PELD (Projeto Ecológico de Longa Duração cuja vegetação foi inventariada, utilizando-se dez faixas paralelas entre si e perpendiculares à direção da posição topográfica, as quais apresentaram 10 m de largura e 100 m de comprimento, subdivididas em dez unidades de 100 m² onde foram sorteadas três unidades amostrais por faixa para identificação e medição (altura e circunferência de indivíduos com Cap maior ou igual a 3 cm e menor de 30 cm. Os cipós, trepadeiras e ervas também tiveram suas circunferências medidas e identificados até o nível de espécie, quando possível. Os dados de densidade por espécie formaram uma matriz (180x70 utilizada na análise multivariada. A presença de agrupamento de vegetação em estado de regeneração natural no interior da floresta foi testada pelo Método TWINSPAN (Two-way indicator species analysis. Constatou-se a existência de três grupos ecológicos (G-1, G-2 e G-3. O G-1 foi caracterizado por boa disponibilidade hídrica, por possuir características ambientais intermediárias e por situar-se na posição topográfica referente à encosta média; G-2 ocorreu na encosta inferior da floresta, apresentando forte influência da umidade e sujeita a alagamentos espor

Florística da vegetação arbustivo - arbórea colonizadora de uma área degradada por mineração de caulim, em Brás Pires, MG Floristic of shrub - tree vegetation colonizing an area degraded by kaolin mining, in Brás Pires, MG

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Fernanda Squizzatto de Araújo

2005-12-01

Full Text Available Este estudo teve como objetivos analisar a composição florística da vegetação arbustivo-arbórea colonizadora de uma área degradada por mineração de caulim, em Brás Pires, MG, compará-la com outros fragmentos florestais e caracterizar aspectos de auto-ecologia das espécies e o solo da área. O levantamento florístico abrangeu uma área de 0,5 ha, subdividida em 50 parcelas contíguas de 10 m x 10 m. Foram incluídos todos os indivíduos com CAP igual ou superior a 10 cm. A composição florística é o resultado desse levantamento acrescida de coletas fora da área de amostragem, totalizando 64 espécies, distribuídas em 50 gêneros e 30 famílias. As famílias com maior número de espécies foram Leguminosae (11, Annonaceae (5, Lauraceae e Melastomataceae (4, enquanto o gênero mais rico foi Machaerium (3. A análise do substrato, nas condições em que se encontrava, revelou que este não impedia o estabelecimento da vegetação. A síndrome de dispersão preponderante era a zoocórica, destacando-se a importância de indivíduos remanescentes, fragmentos próximos e sua fauna associada. A maior similaridade florística ocorreu com o fragmento em Cruzeiro, SP, estando ambas as áreas em início de sucessão.This study aimed to analyze the floristic composition of shrub-tree vegetation colonizing an area degraded by kaolin mining in Brás Pires, MG, compare it with other forest fragments and characterize ecological aspects of species and soil of the area. The sampled area was 0.5 ha subdivided in 50 grid plots of 10x10 meters each. All individuals included had CAP equal or larger than 10cm. The floristic composition is the result of the sampled area plus species collected outside of it. A total of 64 species was obtained, distributed in 50 genera and 30 families. The families with the greater number of species were Leguminosae (11, Annonaceae (5, Lauraceae e Melastomataceae (4, while the richest genus was Machaerium (3. The soil

Meat quality of lambs fed silk flower hay (Calotropis procera SW in the diet Qualidade de carne de cordeiros alimentados com feno de flor-de-seda (Calotropis procera SW na dieta

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Roberto Germano Costa

2011-06-01

Full Text Available The objective of this work was to evaluate the influence of using silk flower hay replacing corn and soybean meal on physical-chemical and sensorial traits of lamb meat. It was used 32 intact Morada Nova male lambs (12.7 ± 2 kg initial body weigth on feedlot system, distributed in a completely randomized design with four levels (0, 15, 30 and 45% on dry matter basis. The use of silk flower hay in the diet influenced quality of meat and carcass, leg weight, tissue composition, moisture, juiciness and flavor. Replacing corn (26.67% and soybean (3.33% with silk flower hay does not affect the tissue composition, ratios and muscularity index of leg and physical-chemical parameters of semimembranosus muscle of Morada Nova lambs.Objetivou-se avaliar a influência do uso de feno de flor-de-seda em substituição ao milho e ao farelo de soja nas características físico-químicas e sensoriais da carne de cordeiros. Utilizaram-se 32 cordeiros Morada Nova, machos não-castrados (12,7 ± 2 kg de peso vivo inicial, em confinamento, distribuídos em delineamento inteiramente ao acaso com quatro níveis (0, 15, 30 e 45% com base na MS. A utilização de feno de flor-de-seda na dieta influenciou a qualidade da carcaça e da carne, o peso da perna, a composição tecidual, a umidade, a suculência e o sabor. A substituição do milho (26,67% e da soja (3,33% pelo feno de flor-de-seda não altera composição tecidual, relação e índice de muscularidade da perna e os parâmetros físico-químicos do músculo semimembranosus de cordeiros Morada Nova.

Aspectos florísticos e fitossociológicos da reserva Capão de Tupanciretã, Tupanciretã, RS, Brasil.

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Suzana Ferreira da Rosa

2008-01-01

Full Text Available Este trabalho foi realizado na Reserva Capão de Tupanciretã, município de Tupanciretã (RS, em uma área com 8 hectares pertencente à Fundação de Pesquisa Agropecuária do Rio Grande do Sul (FEPAGRO. O objetivo do trabalho foi avaliar a composição florística e estrutura fitossociológica da floresta. Utilizaram-se dez parcelas de tamanho 10 x 20 m distribuídas sistematicamente na área. Nessas parcelas, foram medidos e identificados todos os indivíduos com DAP maior ou igual a 5 cm. Dentro das parcelas principais, alocaram-se subunidades de 5 x 5 m para avaliar o componente arbustivo (DAP entre 1 e 5 cm e de 2 x 2 m para a regeneração natural (DAP menor que 1 cm e altura superior a 30 cm. Os resultados foram analisados usando o programa FITOANALISE, calculando-se os parâmetros fitossociológicos tradicionais de densidade, dominância, freqüência, valor de importância, valor de cobertura e índice de diversidade. As espécies com maior representatividade no componente arbóreo da floresta foram Camboatá-vermelho (Cupania vernalis Cambess. e o Branquilho (Sebastiania commersoniana (Baill. L. B. Sm. & Downs. No componente arbustivo e na regeneração, as espécies que apresentaram o maior número de indivíduos foram Camboatá-vermelho (Cupania vernalis Cambess., Primavera (Brunfelsia australis Benth., Chal-chal (Allophylus edulis (A. St.–Hil, Cambess. & A. Juss. e Canela-amarela (Nectandra lanceolata Nees

Análise das variações florísticas e estruturais da comunidade arbórea de um fragmento de floresta semidecídua às margens do rio Capivari, Lavras-MG

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Souza Josival Santos

2003-01-01

Full Text Available Realizou-se um estudo das variações florísticas e estruturais da comunidade arbórea em um fragmento de Floresta Estacional Semidecídua situado às margens do rio Capivari, em Lavras, Minas Gerais, com o objetivo de analisar as correlações entre variáveis ambientais (edáficas, topográficas e morfométricas do fragmento e a distribuição das espécies arbóreas. Procurou-se, também, ampliar o conhecimento sobre a composição florística e a estrutura fitossociológica das comunidades arbóreas da região do alto rio Grande. As espécies arbóreas foram amostradas em coletas extensivas na área e intensivas dentro de 28 parcelas de 20 20 m, tendo sido considerados apenas os indivíduos com DAP > 5 cm. As parcelas foram distribuídas em cinco transeções, dispostas paralelamente à inclinação predominante do terreno. As variáveis ambientais foram obtidas por meio do levantamento topográfico do fragmento e de análises químicas e granulométricas de amostras dos solos. As correlações entre distribuição das abundâncias das espécies e as variáveis ambientais nas parcelas foram avaliadas por análise de correspondência canônica (CCA. A listagem florística registrou 166 espécies, sendo 140 encontradas dentro das parcelas. A comunidade arbórea apresentou um elevado índice de diversidade de Shannon (H' = 4,258 nats/indivíduo, correlacionado à baixa dominância ecológica (alta equabilidade de Pielou, J' = 0,862 e, possivelmente, à alta heterogeneidade ambiental local. A CCA demonstrou que a heterogeneidade ambiental do fragmento é caracterizada principalmente pela topografia acidentada e pelas variações de fertilidade, granulometria e regime hídrico dos solos, sendo este último o mais fortemente correlacionado com a distribuição das espécies. Muitas espécies arbóreas mostraram clara preferência por dois habitats: a baixa encosta, com solos mais úmidos e férteis, e a alta encosta, com solos menos úmidos e f

L-histidine inhibits biofilm formation and FLO11-associated phenotypes in Saccharomyces cerevisiae flor yeasts.

Science.gov (United States)

Bou Zeidan, Marc; Zara, Giacomo; Viti, Carlo; Decorosi, Francesca; Mannazzu, Ilaria; Budroni, Marilena; Giovannetti, Luciana; Zara, Severino

2014-01-01

Flor yeasts of Saccharomyces cerevisiae have an innate diversity of Flo11p which codes for a highly hydrophobic and anionic cell-wall glycoprotein with a fundamental role in biofilm formation. In this study, 380 nitrogen compounds were administered to three S. cerevisiae flor strains handling Flo11p alleles with different expression levels. S. cerevisiae strain S288c was used as the reference strain as it cannot produce Flo11p. The flor strains generally metabolized amino acids and dipeptides as the sole nitrogen source, although with some exceptions regarding L-histidine and histidine containing dipeptides. L-histidine completely inhibited growth and its effect on viability was inversely related to Flo11p expression. Accordingly, L-histidine did not affect the viability of the Δflo11 and S288c strains. Also, L-histidine dramatically decreased air-liquid biofilm formation and adhesion to polystyrene of the flor yeasts with no effect on the transcription level of the Flo11p gene. Moreover, L-histidine modified the chitin and glycans content on the cell-wall of flor yeasts. These findings reveal a novel biological activity of L-histidine in controlling the multicellular behavior of yeasts [corrected].

Análise florística e estrutural de um fragmento de Floresta Ombrófila Mista Montana, situado em Criúva, RS - Brasil.

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Rubens Marques Rondon Neto

2010-08-01

Full Text Available O presente trabalho teve como objetivo conhecer e analisar a composição florística e descrever a estrutura do componente arbóreo de um fragmento de Floresta Ombrófila Mista Montana, localizado no município de Criúva, RS. Em oito parcelas de 10 x 100 m foram inventariados 673 indivíduos com DAP  5 cm, distribuídos em 37 espécies, pertencentes a 32 gêneros e 22 famílias. O valor do índice de diversidade de Shannon foi de 2,768. As famílias que apresentaram maior número de indivíduos amostrados são: Araucariaceae, Myrsinaceae, Euphorbiaceae, Anacardiaceae e Rutaceae. O dossel dessa floresta é dominado pela Araucaria angustifolia e o sub-bosque por espécies das famílias Lauraceae e Myrtaceae. A densidade total encontrada foi de 841,25 indivíduos/ha, com DAP médio de 24,01 cm e altura média de 9,34 m. As cinco espécies que tiveram os maiores valores de importância, em ordem decrescente, foram: Araucaria angustifolia, Sebastiania commersoniana, Lithraea brasiliensis, Zanthoxylum rhoifolium e Myrcia sp.. O fragmento apresenta uma considerável diversidade florística de espécies, apesar das perturbações sofridas no passado. Para que a vegetação atinja as características florísticas e estruturais próximas às da vegetação original é preciso evitar a presença de bovinos e eqüinos na área e explorações da floresta.

A set of haploid strains available for genetic studies of Saccharomyces cerevisiae flor yeasts.

Science.gov (United States)

Coi, Anna Lisa; Legras, Jean-Luc; Zara, Giacomo; Dequin, Sylvie; Budroni, Marilena

2016-09-01

Flor yeasts of Saccharomyces cerevisiae have been extensively studied for biofilm formation, however the lack of specific haploid model strains has limited the application of genetic approaches such as gene knockout, allelic replacement and Quantitative Trait Locus mapping for the deciphering of the molecular basis of velum formation under biological ageing. The aim of this work was to construct a set of flor isogenic haploid strains easy to manipulate genetically. The analysis of the allelic variations at 12 minisatellite loci of 174 Saccharomyces cerevisiae strains allowed identifying three flor parental strains with different phylogenic positions. These strains were characterized for sporulation efficiency, growth on galactose, adherence to polystyrene, agar invasion, growth on wine and ability to develop a biofilm. Interestingly, the inability to grow on galactose was found associated with a frameshift in GAL4 gene that seems peculiar of flor strains. From these wild flor strains, isogenic haploid strains were constructed by deleting HO gene with a loxP-KanMX-loxP cassette followed by the removal of the kanamycin cassette. Haploid strains obtained were characterized for their phenotypic and genetic properties and compared with the parental strains. Preliminary results showed that the haploid strains represent new tools for genetic studies and breeding programs on biofilm formation. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Nexo causal em matéria penal: análise da jurisprudência dos tribunais de justiça Case law regarding causal relationship between conduct and result to attribute criminal liability in brazilian state supreme courts

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Luisa Moraes Abreu Ferreira

2011-06-01

Full Text Available Este artigo discute uma pesquisa empírica apresentada em 2009 como Trabalho de Conclusão de Curso na Direito GV sobre a definição da causalidade para responsabilização criminal nos tribunais de justiça. Foram analisadas 84 apelações criminais julgadas entre 2007 e 2008 e extraídos resultados quantitativos e qualitativos relacionados aos dados do processo, ao resultado da decisão e à argumentação. A análise desses resultados levou a cinco principais constatações: (1 a discussão sobre nexo causal ocorre quase exclusivamente em casos de crimes culposos; (2 muitas vezes, apesar de discutido pelas partes, a existência de nexo causal não é afirmada no acórdão; (3 o nexo causal é frequentemente afirmado com pouca fundamentação e, em geral, com menos argumentos do que a afirmação de culpa; (4 a teoria mais utilizada pelos tribunais é a da equivalência das condições; e (5 o nexo causal é frequentemente afirmado como decorrência da culpa.This paper reports empirical research presented in 2009 as final dissertation for graduation as bachelor of laws at direito gv about the definition of causation to attribute criminal liability in the brazilian state supreme Courts. A total of 84 criminal appeals, ruled between 2007 and 2008, were analyzed and quantitative and qualitative results related to procedure data, results of the decision and reasoning were extracted. Analysis of these results led to five major findings: (1 discussion of causation occurs almost exclusively in cases of willful crimes, (2 often, though discussed by the parties, a causal relationship is not asserted in the decision, (3 causal relationship is often stated with little reasoning and, generally, with fewer arguments than the statement of negligence, (a the causal theory most used by the courts is that cause is every necessary condition for the event, and (5j causal relationship is often asserted as a result of negligence.

Florística em um hectare de cerrado stricto sensu na ARIE - cerrado Pé-de-Gigante, Santa Rita do Passa Quatro, SP

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Weiser Veridiana de Lara

2001-01-01

Full Text Available Foi realizado um levantamento florístico em um ha de cerrado stricto sensu, na parte norte da ARIE - Cerrado Pé-de-Gigante, Santa Rita do Passa Quatro, São Paulo. Foram coletados 428 espécimes em fase reprodutiva, em vinte e cinco excursões de coleta, durante o período de novembro de 1996 a abril de 1998. A listagem florística obtida apresenta 141 espécies, distribuídas em 109 gêneros e 49 famílias. As famílias mais representativas foram: Leguminosae, Asteraceae, Malpighiaceae e Myrtaceae. A floração e frutificação das espécies foram maiores no período chuvoso. Espécies zoocóricas (61 predominaram, seguidas pelas anemocóricas (46 e autocóricas (34. Analisou-se a flora como um todo e seus componentes herbáceo-subarbustivo e arbustivo-arbóreo, separadamente.

A Collaboration in Support of LBA Science and Data Exchange: Beija-flor and EOS-WEBSTER

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Schloss, A. L.; Gentry, M. J.; Keller, M.; Rhyne, T.; Moore, B.

2001-12-01

The University of New Hampshire (UNH) has developed a Web-based tool that makes data, information, products, and services concerning terrestrial ecological and hydrological processes available to the Earth Science community. Our WEB-based System for Terrestrial Ecosystem Research (EOS-WEBSTER) provides a GIS-oriented interface to select, subset, reformat and download three main types of data: selected NASA Earth Observing System (EOS) remotely sensed data products, results from a suite of ecosystem and hydrological models, and geographic reference data. The Large Scale Biosphere-Atmosphere Experiment in Amazonia Project (LBA) has implemented a search engine, Beija-flor, that provides a centralized access point to data sets acquired for and produced by LBA researchers. The metadata in the Beija-flor index describe the content of the data sets and contain links to data distributed around the world. The query system returns a list of data sets that meet the search criteria of the user. A common problem when a user of a system like Beija-flor wants data products located within another system is that users are required to re-specify information, such as spatial coordinates, in the other system. This poster describes methodology by which Beija-flor generates a unique URL containing the requested search parameters and passes the information to EOS-WEBSTER, thus making the interactive services and large diverse data holdings in EOS-WEBSTER directly available to Beija-flor users. This "Calling Card" is used by EOS-WEBSTER to generate on-demand custom products tailored to each Beija-flor request. Through a collaborative effort, we have demonstrated the ability to integrate project-specific search engines such as Beija-flor with the products and services of large data systems such as EOS-WEBSTER, to provide very specific information products with a minimal amount of additional programming. This methodology has the potential to greatly facilitate research data exchange by

Composição florística do componente arbustivo-arbóreo em dois trechos de floresta estacional semidecidual na Mata do Paraíso, Viçosa, MG

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Sheila Isabel do Carmo Pinto

2013-09-01

Full Text Available É grande a demanda por estudos ecológicos em florestas que possam embasar trabalhos de recuperação e conservação da biodiversidade. Entre esses estudos, primordialmente está o levantamento da flora. Nesse sentido, realizou-se o estudo das variações florísticas do componente arbustivo-arbóreo em dois trechos de Floresta Estacional Semidecidual, floresta inicial e floresta madura, situados na Reserva Florestal Mata do Paraíso, em Viçosa, Minas Gerais. As espécies arbóreo-arbustivas foram amostradas dentro de 20 parcelas de 10 x 30 m, 10 parcelas em cada trecho de floresta, sendo considerados apenas os indivíduos com diâmetro a 1,30 m do solo (DAP  4,8 cm. Na floresta inicial foram amostradas 55 espécies pertencentes a 47 gêneros e 27 famílias. A família com maior riqueza florística foi Fabaceae, com 10 espécies (18%, seguida de Euphorbiaceae (cinco espécies; 9%, Annonaceae, Lauraceae, Meliaceae e Salicaceae (três espécies; 6%. Na floresta madura foram amostradas 78 espécies distribuídas em 62 gêneros e 31 famílias. A família com maior riqueza florística foi Fabaceae, com 13 espécies (17%, seguida de Lauraceae e Myrtaceae (seis espécies; 8%, Euphorbiaceae, Sapindaceae e Salicaceae (cinco espécies; 6%, Annonaceae e Meliaceae (quatro espécies, 5%, Rubiaceae e Moraceae (três espécies; 4%. O grupo ecológico que mais se destacou nos dois trechos de floresta foi o das secundárias iniciais, seguido pelas secundárias tardias na floresta madura e pelas pioneiras na floresta inicial. A variabilidade na composição florística e na proporção de espécies em cada grupo ecológico foi resultante das variações na intensidade da ação antrópica nestas florestas e do tempo de regeneração florestal.

Whole-Genome Analysis of Three Yeast Strains Used for Production of Sherry-Like Wines Revealed Genetic Traits Specific to Flor Yeasts

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Eldarov, Mikhail A.; Beletsky, Alexey V.; Tanashchuk, Tatiana N.; Kishkovskaya, Svetlana A.; Ravin, Nikolai V.; Mardanov, Andrey V.

2018-01-01

Flor yeast strains represent a specialized group of Saccharomyces cerevisiae yeasts used for biological wine aging. We have sequenced the genomes of three flor strains originated from different geographic regions and used for production of sherry-like wines in Russia. According to the obtained phylogeny of 118 yeast strains, flor strains form very tight cluster adjacent to the main wine clade. SNP analysis versus available genomes of wine and flor strains revealed 2,270 genetic variants in 1,337 loci specific to flor strains. Gene ontology analysis in combination with gene content evaluation revealed a complex landscape of possibly adaptive genetic changes in flor yeast, related to genes associated with cell morphology, mitotic cell cycle, ion homeostasis, DNA repair, carbohydrate metabolism, lipid metabolism, and cell wall biogenesis. Pangenomic analysis discovered the presence of several well-known “non-reference” loci of potential industrial importance. Events of gene loss included deletions of asparaginase genes, maltose utilization locus, and FRE-FIT locus involved in iron transport. The latter in combination with a flor-yeast-specific mutation in the Aft1 transcription factor gene is likely to be responsible for the discovered phenotype of increased iron sensitivity and improved iron uptake of analyzed strains. Expansion of the coding region of the FLO11 flocullin gene and alteration of the balance between members of the FLO gene family are likely to positively affect the well-known propensity of flor strains for velum formation. Our study provides new insights in the nature of genetic variation in flor yeast strains and demonstrates that different adaptive properties of flor yeast strains could have evolved through different mechanisms of genetic variation. PMID:29867869

A identidade à flor da pele: etnografia da prática da tatuagem na contemporaneidade

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Andrea Lissett Pérez

2006-04-01

Full Text Available No presente artigo, realiza-se uma descrição etnográfica da prática da tatuagem na contemporaneidade, a partir de uma perspectiva que prioriza as noções da prática, das interações e das experiências vividas durante o processo de ser tatuado. A reflexão tenta reconstruir uma visão total da prática da tatuagem que abrange o mundo subjetivo e as dinâmicas sociais como partes constitutivas desse ato. Entre as idéias conclusivas estão, de um lado, o surgimento de uma nova normalidade estética e vivencial no seio da sociedade ocidental e, de outro, a configuração de uma nova subjetividade, a dos "tatuados", como um processo interativo, inovador, emotivo e reflexivo, em que o corpo se converte em uma forma de expressão e construção do sujeito.This article provides a descriptive account of contemporary tattooing, based on a perspective that prioritizes the notion of practice, as well as the interactions and experiences involved in the process of being tattooed. The analysis attempts to rebuild a holistic view of tattooing, combining subjective processes and social dynamics as equally constitutive parts of this activity. Among the conclusions reached are: (a the emergence of tattooing as a new aesthetic norm and a lived experience at the heart of the western society; and (b the configuration of a new subjectivity, the ‘tattooed,’ as an interactive, innovative, emotional and reflexive process in which the body is converted into a form of expressing and constructing the subject.

Florística e variação espaço-temporal de macrófitas aquáticas em reservatórios de abastecimento da Bacia do Rio Iguaçu, PR, Brasil

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Silva, Suelen Cristina Alves da

2013-01-01

Resumo: Macrófitas aquáticas são estruturadoras do ecosistema proporcionando a ciclagem de nutrientes na coluna d'água, além de promover abrigo à fauna aquática. Contudo, a poluição aquática pode promover a intensa proliferação dessas plantas causando efeitos deletérios ao meio aquático além de encarecer os custos com manutenção de turbinas e grades de segurança em reservatórios. O objetivo do presente trabalho foi realizar um levantamento florístico e estudo ecológico da variação espaço-temp...

El daño y el nexo causal en la perdida de oportunidad

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Herrera Montañez, Diego Alejandro

2016-01-01

El presente escrito se ocupa de estudiar el nexo de causalidad como elemento estructural de la responsabilidad cuando éste es difuso. Para ello, se pretende abordar la pérdida de la oportunidad como una teoría especial de causalidad que tiene lugar cuando el nexo causal no resulta claro, lo cual contradice la tesis preponderante de la doctrina y la jurisprudencia tradicional según la cual, la pérdida de la oportunidad es un criterio autónomo del daño. En su contenido se realiza una explic...

Genomic signatures of adaptation to wine biological ageing conditions in biofilm-forming flor yeasts.

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Coi, A L; Bigey, F; Mallet, S; Marsit, S; Zara, G; Gladieux, P; Galeote, V; Budroni, M; Dequin, S; Legras, J L

2017-04-01

The molecular and evolutionary processes underlying fungal domestication remain largely unknown despite the importance of fungi to bioindustry and for comparative adaptation genomics in eukaryotes. Wine fermentation and biological ageing are performed by strains of S. cerevisiae with, respectively, pelagic fermentative growth on glucose and biofilm aerobic growth utilizing ethanol. Here, we use environmental samples of wine and flor yeasts to investigate the genomic basis of yeast adaptation to contrasted anthropogenic environments. Phylogenetic inference and population structure analysis based on single nucleotide polymorphisms revealed a group of flor yeasts separated from wine yeasts. A combination of methods revealed several highly differentiated regions between wine and flor yeasts, and analyses using codon-substitution models for detecting molecular adaptation identified sites under positive selection in the high-affinity transporter gene ZRT1. The cross-population composite likelihood ratio revealed selective sweeps at three regions, including in the hexose transporter gene HXT7, the yapsin gene YPS6 and the membrane protein coding gene MTS27. Our analyses also revealed that the biological ageing environment has led to the accumulation of numerous mutations in proteins from several networks, including Flo11 regulation and divalent metal transport. Together, our findings suggest that the tuning of FLO11 expression and zinc transport networks are a distinctive feature of the genetic changes underlying the domestication of flor yeasts. Our study highlights the multiplicity of genomic changes underlying yeast adaptation to man-made habitats and reveals that flor/wine yeast lineage can serve as a useful model for studying the genomics of adaptive divergence. © 2017 John Wiley & Sons Ltd.

Composição florística de uma floresta estacional semidecidual montana no município de Viçosa-MG Floristic composition of a montane seasonal semideciduous tropical forest in Viçosa, MG, Brasil

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João Augusto Alves Meira-Neto

2002-08-01

Full Text Available O objetivo do presente estudo foi investigar a composição florística arbórea da Mata da Silvicultura (20º45'S e 42º55'W, município de Viçosa, Zona da Mata de Minas Gerais, com o intuito de avaliar sua similaridade com outras florestas. Para comparação florística foi utilizada a análise de agrupamentos pelo método de médias aritméticas não-ponderadas (UPGMA, a partir dos índices binários de similaridade de Sørensen entre as florestas comparadas. Foram relacionadas 154 espécies de 47 famílias botânicas para a Mata da Silvicultura. Esta mata mostrou-se mais similar às florestas semideciduais de altitude de Lavras (MG e de Atibaia (SP e menos similar às florestas submontanas e litorâneas. Estes resultados evidenciam uma importante influência das temperaturas na determinação do tipo florístico das florestas do Sudeste e Sul brasileiros.This study aims to investigate the floristic composition of the Silvicultura forest (20º45`S and 42º55´W by comparing it to other forest compositions. Thus, the cluster analysis method of unweighted pair-group using arithmetic averages (UPGMA was used, applying the Sørensen binary similarity index found among compared forests. A list of 154 species of 47 families was recorded. The Silvicultura forest is more similar to the montane semideciduous forests of Lavras and Atibaia, but less similar to submontane and coastal forests. These results show that temperature plays an important role in the floristic differentiation of the southern and southeastern Brazilian forest types.

Interação de fatores biofísicos e antrópicos com a diversidade florística na indicação de áreas para conservação do Bioma Caatinga

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Costa, Thomaz Correa e Castro; Accioly, Luciano José de Oliveira; Oliveira, Luciana Mara Temponi; Oliveira, Maria Aparecida José de; Guimarães, Daniel Pereira

2009-01-01

p.19-37 A diversidade florística da caatinga foi relacionada com fatores biofísicos e antrópicos para indicação de áreas para conservação. Utilizou-se a análise multicritério para indicar regiões favoráveis à maior diversidade, por meio de fatores biofísicos, e regiões com menor pressão antrópica, a partir de variáveis sócio-econômicas extraídas do censo agropecuário. Os resultados foram comparados com inventários florísticos, fitossociológicos e de biomassa, no qual alguns fatores apresen...

Florística e fitossociologia em um trecho de restinga no Litoral Norte do Estado da Bahia

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Christiano Marcelino Menezes

2011-11-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2012v25n1p31 As restingas são ambientes geologicamente recentes e as espécies que as habitam são típicas de ecossistemas adjacentes como as Florestas Ombrófilas, as Matas de Tabuleiro e a Caatinga, sendo este, o aspecto mais importante na sua composição de espécies, que é composta por diversas formas biológicas, tais como árvores, arbustos, herbáceas eretas e reptantes. O estudo foi realizado no Município de Mata de São João na vila de Praia do Forte, localizada ao longo do Litoral Norte do Estado da Bahia. Com o objetivo de avaliar se há existência de diferentes comunidades vegetais em um trecho de restinga, foram locadas quatro transecções de 200m com cinco unidades amostrais de 100m2 cada. Ao final do estudo foram amostrados 1.640 indivíduos distribuídos em 68 espécies. Os dados florísticos e fitossociológicos associados à análise de Cluster apontam a existência de duas comunidades vegetais distintas, sendo elas uma Mata de Restinga (Transecções 3 e 4 e uma Restinga em Moitas (Transecções 1 e 2. Uma elevada diversidade de espécies foi detectada nas transecções 1 e 2 (H’ = 3,882 e 3 e 4 (H’ =3,835, além de uma diferença significativa na composição das espécies entre elas (p < 0,001. As famílias mais representativas em número de espécies foram: Myrtaceae, Rubiaceae e Malpighiaceae.

Estádio sucessional e fatores geográficos como determinantes da similaridade florística entre comunidades florestais no Planalto Atlântico, Estado de São Paulo, Brasil

OpenAIRE

Durigan,Giselda; Bernacci,Luís Carlos; Franco,Geraldo Antonio Daher Correa; Arbocz,Géza de Faria; Metzger,Jean Paul; Catharino,Eduardo Luís Martins

2008-01-01

A análise das relações de similaridade florística entre comunidades geralmente conduz ao estabelecimento de padrões, condicionados por fatores diversos que determinam a ocorrência ou não das espécies em diferentes locais. Em busca de tais padrões, foram analisadas as relações de similaridade florística entre comunidades florestais localizadas na região do Planalto de Ibiúna, estado de São Paulo, Brasil. Incluíram-se na análise 21 fragmentos florestais e seis sítios em uma Reserva Florestal co...

Composição florística e fitossociologia do cerrado sentido restrito no município de Água Boa - MT

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Felfili Jeanine Maria

2002-01-01

Full Text Available O estudo foi conduzido no município de Água Boa , no Vale do Araguaia, área de ecótono entre o Cerrado e Amazônia, que apresenta um complexo vegetacional com o predomínio do cerrado. O objetivo deste trabalho foi estudar a composição florística e a fitossociologia do cerrado sentido restrito na região. Foram alocadas dez parcelas de 20x50m (1000m². Entraram na amostragem todos os indivíduos lenhosos com diâmetro no nível do solo igual ou superior a 5cm. Além da amostragem com identificação in loco das espécies, foram efetuadas incursões de coleta em áreas próximas, para ampliar o levantamento da composição florística. Foram encontradas 34 famílias botânicas, contendo 60 gêneros e 80 espécies. A família Leguminosae apresentou o maior número de espécies (10, seguida por Myrtaceae (7, Vochysiaceae (6 e Malpighiaceae (5. Outras 19 famílias foram representadas por uma única espécie. As espécies com maior Índice de Valor de Importância foram Curatella americana L., Qualea parviflora Mart., Callisthene fasciculata Mart., Mezilaurus crassiramea (Meiss Taub. e Byrsonima crassa Nied. Treze espécies estiveram representadas por um único indivíduo. A densidade foi de 995 indivíduos/ha e a área basal de 7,5 m² /ha. O índice de Shannon encontrado (H' foi de 3,69, evidenciando a alta diversidade da área.

Descriptores para la caracterización y registro de variedades cubanas de Flor de Jamaica (Hibiscus sabdariffa L.)

OpenAIRE

González Cepero, María C

2014-01-01

Se describen las principales características de la Flor de Jamaica (Hibiscus sabdariffa L.) así como el momento y la forma de evaluación The main characteristics of the Flor de Jamaica (Hibiscus sabdariffa L.) are described as well as the evaluation period and evaluation way

Análise florística e estrutural de sistemas silviagrícolas em Tomé-Açu, Pará

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Édson Luis Bolfe

2011-10-01

Full Text Available O objetivo deste trabalho foi analisar a composição florística e estrutural de sistemas silviagrícolas em Tomé-Açu, Pará. Os dados dendrométricos foram obtidos por inventário em 40 parcelas amostrais, com três unidades cada uma, no total de 120 unidades de 10x10 m. Foi inventariada a média de 1.424,3 indivíduos por hectare, pertencentes a 27 famílias e a 54 espécies. Tendo-se considerado a variabilidade dos estágios vegetativos, os diferentes sistemas silviagrícolas (SAF foram divididos em quatro classes hierárquicas: SAF 1, SAF 2, SAF 3, e SAF 4, para estabelecer um sistema de classificação passível de ser utilizado em outras avaliações de campo e em classificações digitais por meio do sensoriamento remoto. Espécies observadas em outros sistemas da região amazônica também foram relevantes para este estudo, especialmente Theobroma cacao, T. grandiflorum e Euterpe oleracea que, juntas, apresentaram médias de frequência relativa de 51%, densidade relativa de 69,2%, dominância relativa de 50,1% e índice de valor de importância de 56,8%. Os dados médios de diversidade florística, abundância, área basal e valor de importância indicam os sistemas silviagrícolas da região de Tomé-Açu como sistemas de produção com potencial econômico e ambiental, se adotado manejo adequado e racional.

Air-liquid biofilm formation is dependent on ammonium depletion in a Saccharomyces cerevisiae flor strain.

Science.gov (United States)

Zara, Giacomo; Budroni, Marilena; Mannazzu, Ilaria; Zara, Severino

2011-12-01

Air-liquid biofilm formation appears to be an adaptive mechanism that promotes foraging of Saccharomyces cerevisiae flor strains in response to nutrient starvation. The FLO11 gene plays a central role in this phenotype as its expression allows yeast cells to rise to the liquid surface. Here, we investigated the role of ammonium depletion in air-liquid biofilm formation and FLO11 expression in a S. cerevisiae flor strain. The data obtained show that increasing ammonium concentrations from 0 to 450 m m reduce air-liquid biofilm in terms of biomass and velum formation and correlate with a reduction of FLO11 expression. Rapamycin inhibition of the TOR pathway and deletion of RAS2 gene significantly reduced biofilm formation and FLO11 expression. Taken together, these data suggest that ammonium depletion is a key factor in the induction of air-liquid biofilm formation and FLO11 expression in S. cerevisiae flor strains. Copyright © 2011 John Wiley & Sons, Ltd.

Produtividade da couve-flor em função da idade de transplantio das mudas e tamanhos de células na bandeja Cauliflower production depending on age of seedling and cell size of the trays

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Maria Carolina Godoy

2005-07-01

Full Text Available O experimento foi realizado de novembro de 2000 a abril de 2001, na UNESP em São Manuel (SP. Estudou-se o efeito do tamanho da célula da bandeja de poliestireno expandido e a idade de transplantio das mudas sobre a produção de couve-flor, híbrido Shiromaru II. Usaram-se bandejas com 128 e 288 células, correspondentes a 34,6 e 9,7 cm³/célula, respectivamente, e mudas transplantadas aos 27, 34, 41 e 48 dias após a semeadura. Os tratamentos foram arranjados como fatorial 2 x 4, dispostos no delineamento de blocos casualizados, com cinco repetições. Foram avaliados, por ocasião do transplantio, o número de folhas, peso fresco, peso seco e área foliar das mudas. A parcela experimental no campo foi constituída por dez plantas. Nas colheitas, avaliaram-se a porcentagem de plantas com cabeça comercial e nestas, o número de folhas, peso fresco e diâmetro da cabeça. A produção total por parcela foi obtida com a soma do peso fresco de todas as cabeças consideradas comerciais. A produção de mudas em bandejas com 128 células proporcionou maior porcentagem de plantas comerciais (64% relativamente às bandejas com 288 células (45%, maior peso médio de cabeça (337 g na bandeja com 128 e 247 g na bandeja com 288 células e maior produção de plantas comerciais (36,9 t/ha em bandeja de 128 células e 19,9 t/ha em bandeja de 288 células. As mudas transplantadas com 32 dias apresentaram maior peso médio de cabeça (319 g. Concluiu-se ser recomendável produzir mudas de couve-flor em bandejas com 128 células.The experiment was carried out from November/2000 to April/2001, in São Manuel, São Paulo State, Brazil. The effect of cell size of two polyestyrene trays and age of seedling at transplanting date was observed, on the production of cauliflower, hybrid Shiromaru II. Trays with 128 and 288 cells, corresponding to 34.6 and 9.7 cm³/cell, respectively, were used with seedlings transplanted at 27; 34; 41 and 48 days after sowing date

Estrutura e composição florística de quatro formações vegetais de restinga no complexo lagunar Grussaí/Iquipari, São João da Barra, RJ, Brasil

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Assumpção Jorge

2000-01-01

Full Text Available Foi estudada a vegetação de restinga do complexo lagunar Grussaí/Iquipari (21°44'S; 41°02'O, que compreende a bacia das lagunas de Grussaí e Iquipari, com aproximadamente 4.800ha. Uma transecção de 25ha (2500x100m foi delimitada no sentido mar/interior e coletas botânicas realizadas entre os anos de 1995 e 1997. As quatro unidades fisionômicas ocorrentes na área foram estudadas e, através do Índice de Valor de Cobertura, foram determinadas as espécies dominantes em cada formação: 1 Formação Praial-Graminóide: Remirea maritima, Ipomoea imperati, Sporobolus virginicus e Chamaecyse thymifolia; 2 Formação Praial com Moitas: Schinus terebinthifolius, Eugenia sulcata, Pilosocereus arrabidae e Cereus fernambucensis; 3 Formação de Clusia: Pera glabrata, Eugenia sulcata, Sideroxylon obtusifolium e Scutia arenicola; 4 Formação Mata de Restinga: Maytenus obtusifolia, Pera glabrata, Protium heptaphyllum e Coccoloba alnifolia. A similaridade florística da área estudada com outras restingas nos Estados do Rio de Janeiro e Espírito Santo não ultrapassou 41%, onde a proximidade geográfica não representou aumento da similaridade. Os resultados ressaltam a variação da flora de restinga ao longo de um pequeno trecho do litoral brasileiro.

FlorNExT®, a cloud computing application to estimate growth and yield of maritime pine (Pinus pinaster Ait.) stands in Northeastern Portugal

Energy Technology Data Exchange (ETDEWEB)

Barreiro, S.; Rua, J.; Tomé, M.

2016-07-01

Aim of the study. To introduce and describe FlorNExT®, a free cloud computing application to estimate growth and yield of maritime pine (Pinus pinaster Ait.) even-aged stands in the Northeast of Portugal (NE Portugal). Area of study: NE Portugal. Material and methods: FlorNExT® implements a dynamic growth and yield modelling framework which integrates transition functions for dominant height (site index curves) and basal area, as well as output functions for tree and stand volume, biomass, and carbon content. Main results: FlorNExT® is freely available from any device with an Internet connection at: http://flornext.esa.ipb.pt/. Research highlights: This application has been designed to make it possible for any stakeholder to easily estimate standing volume, biomass, and carbon content in maritime pine stands from stand data, as well as to estimate growth and yield based on four stand variables: age, density, dominant height, and basal area. FlorNExT® allows planning thinning treatments. FlorNExT® is a fundamental tool to support forest mobilization at local and regional scales in NE Portugal. (Author)

Levantamento florístico do componente arbustivo-arbóreo da vegetação ciliar na bacia do rio Taperoá, PB, Brasil Floristic survey of components of shrub-tree riparian vegetation in the Taperoá river basin, Paraíba State, Brasil

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Alecksandra Vieira de Lacerda

2005-09-01

Full Text Available Considerando o papel relevante e o nível de degradação presente nas áreas ciliares, a pesquisa objetivou estudar a composição florística do componente arbustivo-arbóreo da vegetação ciliar em diferentes ambientes hídricos do semi-árido paraibano na bacia do rio Taperoá. O levantamento florístico foi realizado no período de junho/2002 a fevereiro/2003 e abrangeu nove pontos distribuídos ao longo de rios, riachos, lagoa e açude. A definição das atividades apoiou-se em análise de cartas e mapas da vegetação em escala de 1:100.000 e caminhadas aleatórias que permitiram a realização de coleta de material vegetal, utilizado para identificação por meio de consultas a especialistas e de morfologia comparada, usando bibliografia especializada e análise das exsicatas depositadas no herbário Lauro Pires Xavier - JPB (UFPB, João Pessoa, PB. A vegetação arbustivo-arbórea da mata ciliar nos nove pontos amostrados foi representada por 43 espécies, das quais 41 são pertencentes a 19 famílias, e duas espécies permaneceram indeterminadas. As famílias que apresentaram o maior número de espécies foram Mimosaceae (sete, Caesalpiniaceae (cinco e Euphorbiaceae (cinco. Os resultados da análise de agrupamento indicaram que as áreas ciliares apresentaram certa particularização em termos de composição florística, o que se refletiu nos baixos índices de similaridades entre o conjunto de áreas amostradas.Considering the relevant role and the current level of degradation of riparian areas, this work aimed to study the floristic composition of shrub-tree riparian vegetation at different hydric environments in the Taperoá river basin, in the semi-arid region of the Paraíba State, Northeast Brazil. The survey was performed from June 2002 to February 2003. Nine sampling sites were distributed along rivers and streams, and around lagoon, and dam. The definition of activities was based on the analysis of charts and vegetation maps

Avaliação de larvicidas de origem microbiana no controle da traça-das-crucíferas em couve-flor Evaluation of microbiological larvicides to control diamondback moth in cauliflower

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Daniel G.S. Dias

2004-09-01

Full Text Available Dois inseticidas biológicos à base de Bacillus thuringiensis subspécies kurstaki (Btk e aizawai (Bta e um inseticida não sistêmico de origem biológica, à base de spinosad, foram avaliados em campo contra a traça-das-crucíferas, Plutella xylostella (L.(Lep.: Plutellidae, em cultivo de couve-flor. O experimento foi realizado em Brazlândia, DF, em uma área de produção regular de hortaliças. A lavoura foi conduzida segundo manejo indicado para a região, sem qualquer intervenção que não o controle da praga. O experimento foi realizado no período de julho a setembro de 2002. O delineamento foi de blocos ao acaso, com quatro tratamentos e quatro repetições. Os produtos foram aplicados em função da média do número de furos produzidos pela praga, presentes nas quatro folhas centrais das plantas, sendo os diferentes tratamentos avaliados semanalmente. Quando a média do número de furos atingia valor igual ou superior a seis, os produtos eram aplicados. Adotando-se este procedimento, aplicou-se três vezes o inseticida spinosad e seis vezes os inseticidas Btk e Bta. Os três tratamentos com inseticidas não diferiram entre si, mas diferiram significativamente da testemunha quanto à produção. As áreas tratadas com Btk produziram 78,1% de cabeças comercializáveis, as tratadas com Bta 76,5% e as tratadas com spinosad 75,5%. No controle houve perda de 34,4% da produção. A utilização dos produtos aumentou a receita da cultura da couve-flor em relação à testemunha, nos valores de R$ 2.505,19 com o Btk, R$ 1.954,55 com o Bta e R$ 1.891,65 com spinosad.Two bioinsecticides based on Bacillus thuringiensis sub species kurstaki (Btk and aizawai (Bta and non-systemic insecticide of biological origin based on spinosad were evaluated on cauliflower crop for diamondback moth, Plutella xylostella (L. (Lep.:Plutellidae control. The experiment was conducted in a vegetable production area of Brazlândia, Brazil. The crop was conducted

Composição florística do estrato arbóreo de floresta Atlântica Interiorana em Araponga - Minas Gerais Tree strtum floristc composition of an Inland Atlantic forest in Araponga - MG

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Michellia Pereira Soares

2006-10-01

Full Text Available Os objetivos deste trabalho foram determinar a composição florística de um fragmento de Floresta e analisar a sua similaridade com outras áreas de Floresta Estacional Semidecidual e Floresta Ombrófila Densa, com o intuito de classificar a tipologia florestal da área de estudo. O levantamento foi realizado em uma trilha interpretativa na Pousada Serra D'Água (20º41'24"S e 42º29'47"W, 1.100 m de altitude, região de entorno do Parque Estadual da Serra do Brigadeiro (PESB, Município de Araponga, MG. A listagem florística foi obtida a partir do levantamento fitossociológico, no qual foram demarcados 150 pontos quadrantes. Foram relacionadas 147 espécies, 98 gêneros e 50 famílias. As famílias com maior número de espécies foram: Melastomataceae (14, Leguminosae (11, Myrtaceae (10, Rubiaceae (8, Annonaceae (7, Flacourtiaceae (7, Lauraceae (7 e Meliaceae (6. Os resultados da análise de agrupamento revelaram que os aspectos de proximidade geográfica e altitude são os principais responsáveis pela similaridade florística de muitas áreas. A vegetação da área de estudo pode ser classificada como Floresta Estacional Semidecidual Montana, pelo fato de a sua composição florística mostrar alta similaridade com outras áreas dessa mesma tipologia.The objective of this work was to determine the floristic composition of a forest fragment and to analyze its similarity with other areas of the Semideciduous Seasonal Forest and Dense Ombrophylous Forest, in order to classify the forest typology of this area. The survey was carried out in an interpretative trail at the Pousada Serra D'Água (20º41'24"S and 42º29'47"W, 1100 m altitude, in the region around the Serra do Brigadeiro State Park (PESB, municipality of Araponga, MG. The floristic list was obtained from the phytosociological survey in which 150 quarter-centered-points were established. A total of 147 species, 98 genera and 50 families were found. The families with the greatest

Avaliação do potencial biológico da Tabebuia aurea(Silva Manso como fonte de moléculas bioativas para atividade antimicrobiana, antiedematogênica e antirradicalar

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R.F.E.P. SANTOS

2015-01-01

Full Text Available RESUMO As espécies da família Bignoniaceae e do gênero Tabebuia são amplamente utilizadas na medicina tradicional e possuem um forte potencial terapêutico. Diante disso, objetivou-se avaliar o potencial biológico da Tabebuia aurea, determinando a atividade antimicrobiana; por meio do método da microdiluição em caldo, para a determinação da Concentração Inibitória Mínima (CIM; antiedematogênica, pelo ensaio de edema de orelha induzido por capsaicina; e antirradicalar, frente ao radical DPPH. Os extratos etanólicos de T. aurea não evidenciaram citotoxicidade, exceto o extrato etanólico da flor nas concentrações > 0,5 mg mL-1. O extrato etanólico da flor foi ativo com ação bactericida frente a S. epidermidis (CIM de 0,06 mg mL-1 enquanto o extrato etanólico da folha foi moderadamente ativo frente a S. epidermidis (CIM: 0,25 mg mL-1 e S. aureus (CIM: 0,50 mg mL-1 sugerindo ação bacteriostática para ambas as linhagens. Os dois extratos apresentaram ação antiedematogênica, com inibição do edema de 40,50% pelo extrato etanólico da flor e de 41,73% pelo extrato da folha. T. aurea não apresentou atividade antirradicalar. Os resultados comprovam o perfil antibacteriano e antiedematogênico com ausência de citotoxidade pela T. aurea. Sugere-se a continuação dos testes com frações e substâncias isoladas das flores e folhas da referida espécie vegetal, bem como de experimentos in vivo, como forma de agregar evidências visando à busca de novos fitoterápicos.

FlorNExT®, a cloud computing application to estimate growth and yield of maritime pine (Pinus pinaster Ait. stands in Northeastern Portugal

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Fernando Pérez-Rodríguez

2016-07-01

Full Text Available Aim of the study: To introduce and describe FlorNExT®, a free cloud computing application to estimate growth and yield of maritime pine (Pinus pinaster Ait. even-aged stands in the Northeast of Portugal (NE Portugal. Area of study: NE Portugal. Material and methods: FlorNExT® implements a dynamic growth and yield modelling framework which integrates transition functions for dominant height (site index curves and basal area, as well as output functions for tree and stand volume, biomass, and carbon content. Main results: FlorNExT® is freely available from any device with an Internet connection at: http://flornext.esa.ipb.pt/. Research highlights: This application has been designed to make it possible for any stakeholder to easily estimate standing volume, biomass, and carbon content in maritime pine stands from stand data, as well as to estimate growth and yield based on four stand variables: age, density, dominant height, and basal area. FlorNExT® allows planning thinning treatments. FlorNExT® is a fundamental tool to support forest mobilization at local and regional scales in NE Portugal. Keywords: forest management; maritime pine; forest modelling; knowledge transfer tool.

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

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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

Ecologia da vegetação de orla de bosque de carvalho-negral na Serra da Nogueira, Bragança, Portugal

OpenAIRE

Rocha, S.; Aguiar, Carlos; Azevedo, João

2006-01-01

Avaliou-se o efeito do gradiente "distância à orla" na estrutura e composição florística de dois bosques de Quercus pyrenaica na Serra da Nogueira, Bragança, Portugal. Em cada bosque estabeleceram-se 8 transectos de 40 m com início na orla do bosque e orientados perpendicularmente a esta. Em cada transecto estabeleceram-se bandas de amostragem de 1 x 10 m dispostas perpendiculares aos transactos a 0, 1, 5, 10,20 e 40 m da orla do bosque. Nestas bandas avaliaram-se a composição flo...

Casos de Ensino em Administração: Dona Flor: Desintermediar ou ser Desintermediada!

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Aline Stange

2012-07-01

Full Text Available The Dona Flor teaching case portrays the moment in which Pedro Brasil, founder of an erotic product reseller for women through direct sales, was looking for ways to keep his business healthy and growing. One possibility was derived from the fact that consumers did not recognize specific brands ofproducts, since there were no large companies in the erotic products market. The channel structure of the company, however, hindered the exploitation of this opportunity. The case highlights the fragilityof the company’s relationship with suppliers and with catalog distributors. Students should therefore consider the disintermediation of both upstream and downstream links in the value chain and the implications of this decision for the business. Moreover, the case suggests the possibility that Dona Flor itself was in danger of being disintermediated, requiring the evaluation of strategies to mitigate this risk, which include the development of a private label. The goal is to enable students to sketch the path-to-market diagram, and, based on it, provide alternatives for the company, considering the advantages and disadvantages of each proposal. They should also realize the importance of the differential offered by Dona Flor and the limitations it imposes on the exploitation of different distribution channels.

Study of the role of the covalently linked cell wall protein (Ccw14p) and yeast glycoprotein (Ygp1p) within biofilm formation in a flor yeast strain.

Science.gov (United States)

Moreno-García, J; Coi, A L; Zara, G; García-Martínez, T; Mauricio, J C; Budroni, M

2018-03-01

Flor yeasts are Saccharomyces cerevisiae strains noted by their ability to create a type of biofilm in the air-liquid interface of some wines, known as 'flor' or 'velum', for which certain proteins play an essential role. Following a proteomic study of a flor yeast strain, we deleted the CCW14 (covalently linked cell wall protein) and YGP1 (yeast glycoprotein) genes-codifying for two cell surface glycoproteins-in a haploid flor yeast strain and we reported that both influence the weight of the biofilm as well as cell adherence (CCW14).

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

Alienígenas na sala: o que fazer com espécies exóticas em trabalhos de taxonomia, florística e fitossociologia?

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Marcelo Freire Moro

2012-12-01

Full Text Available A presença cada vez mais disseminada de organismos exóticos (muitos dos quais se tornam invasores nas diferentes regiões do planeta levou ao surgimento de uma linha de pesquisa na ecologia voltada às invasões biológicas. E para permitir a comunicação entre autores também foi desenvolvido um arcabouço terminológico. Mas, apesar disso, a terminologia relativa às bioinvasões tem sido ignorada por boa parte dos botânicos no Brasil. Há uma boa dose de confusão entre botânicos sobre o que seja uma espécie exótica, naturalizada, invasora, daninha e ruderal, levando ao uso inconsistente da terminologia. Além disso, diferentes autores têm adotado posturas praticamente opostas ao lidar com espécies exóticas em suas áreas de estudo, seja na preparação de tratamentos taxonômicos, seja na publicação de levantamentos florísticos e fitossociológicos. Enquanto alguns pesquisadores incluem em floras mesmo espécies cultivadas que não se reproduzem, outros excluem plantas invasoras comuns e conspícuas. Nós apresentamos aqui, em português, os principais conceitos relativos ao tema da bioinvasão e chamamos a atenção dos autores brasileiros para a necessidade de utilizar de modo consistente o arcabouço terminológico já existente na literatura. Também propomos a adoção de rótulos claros para informar quais espécies são exóticas na área estudada, diferenciando-as das nativas, e sugerimos critérios para ajudar botânicos a decidirem quando uma planta exótica deve ou não ser incluída em tratamentos taxonômicos ou levantamentos de florística.

Flora ficologica da plataforma continental do litoral setentrional da bacia potiguar (RN), Brasil, com ênfase em chlorophyta

OpenAIRE

De Lourdes Montenegro Cocentino, Adilma

2009-01-01

Foram estudadas as macroalgas marinhas bentônicas de um habitat pouco explorado (Bacia Potiguar, Rio Grande do Norte, Nordeste do Brasil) e cuja informação florística é rara, para se conhecer a diversidade taxonômica e padrões de distribuição em um infralitoral tropical, onde vários empreendimentos estão em fase de instalação, sendo enfatizadas as Chlorophyta, como indicadoras da qualidade ambiental. Amostragens de macroalgas bentônicas foram feitas, com dois tipos de dragas e ...

Número de anteras por flor, grãos de pólen por antera e capacidade germinativa do pólen de diferentes cultivares de macieiras

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Celso Lopes de Albuquerque Junior

2010-12-01

Full Text Available O objetivo deste trabalho foi avaliar o número de anteras por flor, grãos de pólen por antera e capacidade germinativa do pólen de diferentes cultivares de macieiras. O trabalho foi executado no Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal da Universidade Federal de Santa Catarina, e as coletas a campo foram realizadas na Epagri/Estação Experimental de Caçador-SC, em outubro de 2005. Foram utilizadas as seguintes cultivares comerciais de macieira desenvolvidas no Brasil: Primícia, Princesa, Fred Hough, Catarina, Baronesa, Lisgala, Suprema, Condessa, Daiane, Duquesa, Imperatriz e Joaquina. As cultivares de macieira Condessa, Princesa, Eva, Duquesa, Imperatriz, Gala, Fred Hough, Daiane, Baronesa e Suprema produzem pólen em quantidade suficiente e com boa capacidade germinativa. A cv. Condessa, embora apresente alta capacidade germinativa de pólen, produz menos anteras e grãos de pólen por antera que as demais. A cv. Princesa é a que apresenta o melhor perfil como polinizadora, por conjugar número de anteras/flor, número de grãos de pólen/antera e capacidade germinativa do pólen mais satisfatórios.

Resposta de brócolis, couve-flor e repolho à adubação com boro em solo arenoso Response of boron fertilization on broccoli, cauliflower and cabbage planted in sandy soil

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Luiz Carlos Pizetta

2005-03-01

Full Text Available Foram avaliados em condições de campo, em solo arenoso, com baixo teor de boro, os efeitos da adubação com cinco doses de boro (0; 2; 4; 6 e 8 kg ha-1 de B na forma de bórax na produção de brócolis, couve-flor e repolho. O experimento obedeceu a um esquema fatorial com delineamento experimental de blocos ao acaso com três repetições. As adubações orgânica e química, inclusive o bórax, foram feitas no sulco antes do transplantio das mudas e a colheita foi feita entre 63 e 93 dias após o transplantio. A produtividade de brócolis variou de 16,9 a 20,5 t ha-1; a de couve-flor de 21,6 a 29,6 t ha-1 e a de repolho de 40,5 a 46,4 t ha-1. O aumento observado na produtividade de brócolis e de repolho foi linear e o efeito das doses de boro na produtividade de couve-flor foi quadrático, sendo necessários 5,1 kg ha-1 de B para atingir a produtividade máxima de 30 t ha-1. Brócolis e repolho mostraram-se menos sensíveis do que a couve-flor tanto à deficiência quanto ao excesso de boro. No caso da couve-flor, com a aplicação de 2 kg ha-1 ou de 6 kg ha-1 de B houve significativa perda de qualidade do produto.The effects of boron fertilization on yield of broccoli, cauliflower and cabbage were evaluated through a field experiment carried out on a sandy soil low in available boron. Five boron levels (0; 2; 4; 6; and 8 kg ha-1 B as borax were applied in broccoli, cauliflower and cabbage using a factorial scheme and a randomized block design with three replicates. Organic manure and chemical fertilizers, including borax, were applied in the planting furrow before seedlings transplant and plants were harvested 63 to 93 days after planting date. The yield intervals obtained with broccoli, cauliflower and cabbage varied according to the following intervals: 16.9 to 20.5 t ha-1, 21.6 to 29.6 t ha-1 and 40.5 to 46.3 t ha-1, respectively. The increase in production observed in broccoli and cabbage yield was linear with boron levels and the

Composição florística e a conservação de floresta secundárias na serra da Cantareira, São Paulo, Brasil. Floristic composition and conservation of old secondary Forest in the serra Cantareira in São Paulo, South-Eastern Brazil.

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Frederico Alexandre Roccia Dal Pozzo ARZOLLA

2011-06-01

Full Text Available Florestas secundárias estão seriamente ameaçadas pela expansão urbana na região metropolitana. Alguns remanescentes são protegidos, principalmente em parques estaduais e municipais, mas a maioria dessas florestas está sob risco de supressão pela contínua expansão de áreas urbanas. O objetivo deste trabalho foi caracterizar a composição florística do componente arbóreo de trecho de floresta, em estágio médio a avançado de regeneração no Parque Estadual da Cantareira, São Paulo (SP. Foram realizadas caminhadas nos traçados antigo e novo da Linha de Transmissão Guarulhos–Anhanguera, num total aproximado de 11 km de extensão. A amostragem foi realizada no período de 2006 a 2010. No levantamento florístico, foram identificadas 179 espécies, pertencentes a 54 famílias e 127 gêneros. As famílias com maior riqueza de espécies foram Fabaceae (19 espécies, Myrtaceae (18, Lauraceae (16 e Rubiaceae (15 e os gêneros mais ricos, Ocotea e Myrcia (6, Eugenia (5 e Maytenus, Mollinedia e Nectandra com quatro espécies cada. Foram registradas dez espécies consideradas ameaçadas de extinção, sendo quatro espécies na lista de São Paulo e seis na lista da IUCN. Uma delas, Mollinedia oligotricha, é considerada presumivelmente extinta. A similaridade florística encontrada com outros remanescentes florestais da Região Metropolitana de São Paulo e arredores variou entre 11% a 38%. Florestas secundárias apresentam uma considerável riqueza de espécies, incluindo espécies ameaçadas de extinção. Foram discutidas as pressões incidentes sobre esses remanescentes florestais, bem como possíveis estratégias para a sua conservação.Secondary forests are seriously threatened by urban expansion in the metropolitan region of São Paulo. Some remnants are protected, mainly in state or municipal parks, but most of these forests are in immanent danger of being destroyed by the continual expansion of urban areas. The aim of this

Levantamento florístico e fitossociológico em duas áreas de cerrado sensu stricto no Parque Estadual da Serra de Caldas Novas, Goiás

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Silva Lucivânio Oliveira

2002-01-01

Full Text Available A necessidade de se conhecer mais sobre o Bioma Cerrado torna-se cada vez mais urgente, devido à destruição acelerada deste bioma. Este trabalho teve como objetivo realizar um levantamento florístico e fitossociológico em duas áreas de Cerrado sensu stricto, no Parque Estadual da Serra de Caldas Novas, registrando as espécies arbóreas e arbustivas, utilizando o método de Point Centered Quarter. Verificou-se que apesar de algumas diferenças litológicas, latossolo vermelho-escuro na primeira área e vermelho-amarelo na segunda, a similaridade entre elas foi alta, com índices de Jaccard (0,72 e Morisita (0,64. Das 67 espécies pertencentes a 51 gêneros e 29 famílias, 48 foram comuns às duas áreas. Kielmeyera coriacea, Qualea grandiflora, Caryocar brasiliense, Syagrus flexuosa e Ouratea hexasperma tiveram os maiores Índices de Valor de Importância na primeira área e Pouteria ramiflora, Qualea parviflora, Qualea grandiflora, Caryocar brasiliense e Vochysia cinamommea, foram as espécies de maior importância na segunda área. A família Vochysiaceae foi a de maior IVI em ambas as áreas e Leguminosae apresentou o maior número de espécies (15, seguindo Vochysiaceae (7, Apocynaceae (5 e Myrtaceae (4.

Florística e estrutura da comunidade arbórea de um fragmento florestal em Luminárias, MG Floristic composition and structure of the tree layer of a forest fragment in Luminárias Municipality, Minas Gerais State

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Luciene Alves Rodrigues

2003-03-01

Full Text Available O objetivo deste trabalho foi analisar a composição florística e estrutural da comunidade arbórea de uma floresta em Luminárias, MG. O local de estudo é conhecido como Mata do Galego, possui cerca de 77 ha e está localizado a 21°29'S e 44°55'W, às margens do rio Ingaí. A amostragem florística foi realizada em parcelas e também em caminhadas pela floresta. Todo o material coletado foi identificado e incorporado ao Herbário ESAL, da Universidade Federal de Lavras. O levantamento estrutural foi realizado por meio de amostragem sistemática, em 32 parcelas de 20 × 20m, distribuídas em três transeções, da margem do rio até a borda da mata. Nas parcelas, foram amostrados todos os indivíduos arbóreos, vivos, com circunferência à altura do peito (CAP ≥ 15,5 cm. As variáveis químicas e físicas do solo foram obtidas das análises de amostras superficiais de solo (0-20 cm de cada parcela. No levantamento florístico foram amostradas 201 espécies, 129 gêneros e 57 famílias. As famílias com maior riqueza foram Myrtaceae, Lauraceae, Fabaceae Faboideae, Rubiaceae, Euphorbiaceae e Fabaceae Mimosoideae. No levantamento estrutural foram amostrados 2343 indivíduos de 159 espécies, 104 gêneros e 50 famílias. As espécies mais abundantes foram Casearia sylvestris, Lithraea molleoides, Machaerium stipitatum, Faramea cyanea, Diospyros inconstans e Copaifera langsdorffii. A Mata do Galego apresentou alta diversidade de espécies (H' = 4,23 nat/indivíduo e alta equabilidade (J' = 0,83. A alta diversidade de espécies pode estar relacionada à influência de formações vegetais próximas e aos diferentes microhabitats proporcionados pela topografia, variações na fertilidade e umidade do solo.The aim of this study was to analyze the floristic composition and structure of the tree layer of a forest fragment in the municipality of Luminárias, Minas Gerais State, southeastern Brazil. The forest fragment is locally known as Mata do

Morfologia da flor e formação do fruto no amendoim cultivado (Arachis hypogaea, L. Flower morphology and fruit development in the cultivated peanut (Arachis hypogaea L.

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Candida H. T. M. Conagin

1955-01-01

Full Text Available O amendoim comum pertence à espécie Arachis hypogxa L. ; outras espécies não apresentam valor econômico algum. As variedades comerciais podem ser reunidas em três grupos - Virgínia, Spanish e Valência - de acôrdo com a distribuição das gemas vegetativas e reprodutivas e também com o número de sementes por fruto. Nêste trabalho é apresentado um estudo da morfologia, duração e fertilização da flor, mostrando que no amendoim não existe a suposta distinção de flôres férteis e estéreis. Também a formação do fruto é descrita, mostrando a interessante característica desta planta, que é ter flôres aéreas e frutos subterrâneos.This work is based mostly on the descriptions given in Smith's paper "Arachis hypogxa L. Aerial flower and Subterranean Fruit" (2 and in the symposium "The Peanut. The unpredictable Legume" (3, and also on some of the author's observations. All cultivated peanut varieties belong to the species Arachis hypogxa L.; other species of the genus are not used for commercial production and may be of interest only for breeding purposes. Commercial peanut varieties can be grouped into one of three types : Virginia, Spanish, and Valencia. This grouping is done according to the distribution of vegetative and reproductive buds on the plant, and to the number of seeds per fruit. Studies were made on flower morphology, its duration and fertilization ; they indicated that all peanut flowers are potentially fertile and cannot, therefore, be classed into fertile and infertile types. A description of how the aerial flowers produce subterranean fruits is given.

Ethanol-independent biofilm formation by a flor wine yeast strain of Saccharomyces cerevisiae.

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Zara, Severino; Gross, Michael K; Zara, Giacomo; Budroni, Marilena; Bakalinsky, Alan T

2010-06-01

Flor strains of Saccharomyces cerevisiae form a biofilm on the surface of wine at the end of fermentation, when sugar is depleted and growth on ethanol becomes dependent on oxygen. Here, we report greater biofilm formation on glycerol and ethyl acetate and inconsistent formation on succinic, lactic, and acetic acids.

Florística e fitossociologia da vegetação de um campo sujeito à arenização no sudoeste do Estado do Rio Grande do Sul, Brasil Floristics and phytosociology of grassland vegetation subject to sandy desertification in southwestern Rio Grande do Sul State, Brazil

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Elisete Maria de Freitas

2009-06-01

Full Text Available Extensas áreas de campo nativo do sudoeste do Rio Grande do Sul são suscetíveis ao processo de arenização, que ocorre em áreas de fragilidade pedológica, tendo influência de interferência antrópica e fatores abióticos. Com o objetivo de testar a variação da cobertura vegetal e a dinâmica da arenização no tempo e conforme a influência da distância da encosta, foi desenvolvido um estudo florístico e fitossociológico em áreas de campo nativo sob pastejo. Duas subáreas, diferentes quanto ao processo da arenização, foram selecionadas no município de São Francisco de Assis, RS. O levantamento florístico apontou a ocorrência de 102 espécies, distribuídas em 25 famílias. No estudo fitossociológico, 35 quadros permanentes de 0,25 m² em cada subárea foram dispostos em diferentes distâncias da encosta do morro. Foram registradas as coberturas das espécies vegetais, do mantilho e do solo exposto em três períodos. Dados sobre riqueza e diversidade de espécies e formas de vida foram avaliados por análise de variância, via testes de aleatorização, considerando o fator temporal e o espacial (distância da encosta. Houve maior redução da diversidade específica e da cobertura vegetal na subárea 1 (com menor cobertura vegetal conforme a variação temporal. Na subárea 2 (com maior cobertura vegetal, o aumento do solo exposto e a conseqüente redução da cobertura vegetal tiveram maior influência da distância da encosta. A alteração da cobertura vegetal e a expansão da arenização observadas ao longo do tempo são resultado da influência conjunta da dinâmica pluviométrica, do tipo solo, da presença de encostas dos relevos tabulares com pouca vegetação e da contínua pressão de pastejo.Extensive areas of native grassland in southwestern Rio Grande do Sul are susceptible to sandy desertification, which occurs in pedologically fragile areas influenced by anthropic interference and abiotic factors. A

Diversidad florística del Paisaje Natural Protegido “Estrella-Aguadores”, Santiago de Cuba, Cuba

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Miguel Ángel Castell-Puchades

2016-07-01

Full Text Available El Paisaje Natural Protegido “Estrella-Aguadores” se considera entre las áreas de mayor riqueza florística de la costa suroriental de Cuba, sin embargo, son insuficientes los estudios florísticos locales que les posibilite a técnicos y decisores locales contar con la información necesaria para emprender acciones adecuadas de conservación y manejo; con el objetivo de resolver este problema, realizamos un estudio de la diversidad florística que caracteriza el área protegida. Se desarrolló un muestreo preferencial, sin rumbo fijo, teniendo en cuenta en cada recorrido las características físico-geográficas del área, así como la ecología de las especies. El trabajo de campo se realizó según la metodología de los inventarios biológicos rápidos. Se identifican 266 especies de angiospermas para el Paisaje Natural Protegido “Estrella-Aguadores”, de las cuales 112 constituyen nuevos registros para el área protegida. Se registran 38 especies endémicas y seis especies amenazadas. El 48% de las angiospermas registradas presentan algún tipo de uso o valor para los comunitarios. Este trabajo muestra al Paisaje Natural Protegido “Estrella-Aguadores” como una de las reservas más importantes en diversidad de angiospermas de las terrazas costeras de Cuba, lo cual resalta su función como área de protección de la flora.

Ethanol-Independent Biofilm Formation by a Flor Wine Yeast Strain of Saccharomyces cerevisiae▿

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Zara, Severino; Gross, Michael K.; Zara, Giacomo; Budroni, Marilena; Bakalinsky, Alan T.

2010-01-01

Flor strains of Saccharomyces cerevisiae form a biofilm on the surface of wine at the end of fermentation, when sugar is depleted and growth on ethanol becomes dependent on oxygen. Here, we report greater biofilm formation on glycerol and ethyl acetate and inconsistent formation on succinic, lactic, and acetic acids. PMID:20435772

Composição florística da vegetação arbórea de um trecho de floresta estacional semidecídua em Viçosa, Minas Gerais, e espécies de maior ocorrência na região Floristic composition of trees in a seasonal semidecious forest in Viçosa, Minas Gerais, and species of greater ocurrence in the region

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Walnir Gomes Ferreira Júnior

2007-12-01

Full Text Available É grande a demanda por estudos ecológicos em florestas que possam embasar trabalhos de recuperação, conservação da biodiversidade e apoio à legislação ambiental. Entre esses estudos, primordialmente está o levantamento da flora. Nesse sentido, este trabalho teve como objetivo determinar a composição florística de um trecho da Reserva da Biologia, em Viçosa, MG, em regeneração natural há 80 anos, bem como realizar uma análise comparativa com outros trabalhos conduzidos na região, fornecendo, assim, informações que poderão embasar estudos sobre recuperação e conservação da biodiversidade dos fragmentos de Floresta Estacional Semidecidual. Os dados florísticos foram obtidos mediante a amostragem fitossociológica em 1 ha, pelo método de parcelas contíguas, em que todos os indivíduos arbóreos com circunferência de tronco >15 cm a 1,30 m do solo foram amostrados. Registraram-se 130 espécies, distribuídas em 94 gêneros, pertencentes a 38 famílias botânicas. A análise desses dados conjuntamente com de outros levantamentos realizados em trechos distintos da Reserva da Biologia, no campus da UFV, denota a marcante influência de variáveis ambientais locais (topografia, declividade, face de exposição solar e disponibilidade hídrica na distribuição da riqueza florística desse fragmento. Casearia decandra, Guapira opposita, Apuleia leiocarpa, Dalbergia nigra, Jacaranda macratha, Matayba elaeagnoides, Piptadenia gonoacantha, Bathysa nicholsonii, Carpotroche brasiliensis, Luehea grandiflora, Mabea fistulifera, Ocotea odorifera, Sorocea bonplandii e Zanthoxylum rhoifolium foram as espécies de maior ocorrência nos fragmentos estudados na região de Viçosa e adjacências, apresentando potencial para uso na recuperação florestal de áreas degradadas.There is a great demand for ecological studies on forests focusing on biodiversity conservation and establishment of environmental laws. The major need, however, is

Composição florística de florestas estacionais ribeirinhas no estado de Mato Grosso do Sul, Brasil Floristic composition of seasonal riparian forests in Mato Grosso do Sul state, Brazil

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Vivian Ribeiro Baptista-Maria

2009-06-01

Full Text Available O presente estudo teve como objetivos caracterizar a composição florística em dois trechos de floresta estacional semidecidual associada ao rio Formoso, Bonito, MS, e em três trechos de florestas estacionais deciduais e semideciduais associadas aos rios Salobra, Salobrinha e Perdido ocorrentes no Parque Nacional da Serra da Bodoquena (76.481 ha - única unidade de Conservação Federal de Proteção Integral implantada no Estado de Mato Grosso do Sul. O levantamento florístico foi realizado mensalmente entre o período de outubro/2004 a março/2006, onde foram coletadas fanerógamas em fase reprodutiva (flores e frutos, através do método de tempo de avaliação. O levantamento florístico resultou em 56 famílias, 184 gêneros e 307 espécies. Do total das espécies, 68% apresentaram hábito arbóreo, 17% arbustos, 14% foram lianas e apenas 1% palmeiras. A família Fabaceae (Leguminosae, representada por 51 (16,6% espécies, foi a de maior riqueza. Os resultados obtidos neste trabalho contribuíram para o conhecimento da flora sul-mato-grossense e sua distribuição geográfica, reforçando a necessidade de conservação destas matas ribeirinhas e fornecendo subsídios para os planos de restauração das áreas degradadas do entorno da unidade de conservação e das áreas de proteção permanente (APP's dos rios ocorrentes na região.This study aimed to characterize the floristic composition in two stretches of seasonal semideciduous forest associated with the Formoso River, Bonito, Mato Grosso do Sul State, and in three stretches of seasonal deciduous and semideciduous forests associated with the Salobra, Salobrinha and Perdido rivers in Bodoquena Plateau National Park (76,481 ha - the only Federal Conservation unit with Integral Protection in the state of Mato Grosso do Sul. The floristic survey was carried out monthly from October/2004 to March/2006, where flowering and fruiting phanerogams were collected by the method of evaluation

Análise da composição florística e fitossociológica da floresta nacional do Tapajós com o apoio geográfico de imagens de satélites Analysis of the floristic and phytosociologic composition of Tapajós national forest with geographic support of satellite images

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Fernando Del Bon Espírito-Santo

2005-06-01

Full Text Available O objetivo desse trabalho foi analisar a distribuição da cobertura vegetal de diversas porções da Floresta Nacional (FLONA do Tapajós (FNT, no Pará, através de atributos florísticos e fitossociológicos apoiados por imagens de satélites, em áreas de floresta primária (FP e floresta secundária (FS. Para isso foram amostrados 35 transectos de 10 m ' 250 m em áreas de FP de alto e baixo platô, incluindo também as áreas alteradas por de corte florestal seletivo de madeira e 29 transectos de 10 m ' 100 m em áreas de FS em vários estágios regenerativos. Em cada um desses transectos foram levantadas informações dendrométricas como DAP (Diâmetro à Altura do Peito, altura total (AT e altura comercial (AC, além de localização dos indivíduos arbóreos dentro das amostras. Os diâmetros de inclusão para as áreas de floresta primária e secundária foram de 10 cm e 3 cm, respectivamente. Foram inventariados 7666 indivíduos (6607 árvores ou arbustos e 1059 palmeiras em uma área amostral de 11,65 ha, distribuídos em diferentes regiões da FNT. Foram identificadas em áreas de FP e FS 190 espécies de árvores, arbustos e palmeiras distribuídas entre 153 gêneros e 46 famílias. Nas FP e FS foi encontrado um índice de diversidade de Shannon-Wiener (H' de 4,44 e 4,09 nits.indivíduos-1, respectivamente, indicando uma alta diversidade biológica para essas duas fitofisionomias. Através de análises multivariadas foi possível concluir que existe uma diferença florística e quantitativa na porção norte, centro e sul da FLONA. As áreas de FS apresentaram uma grande heterogeneidade ambiental, dificultando o processo de agrupamento das suas fases sucessionais. Através desse trabalho foi possível concluir que o apoio das imagens ETM+/Landsat e RADARSAT-1 otimizou o processo de amostragem da FNT e possibilitou a análise espacial das regiões com maior diferenciação florística e fitossociológica da Floresta Nacional

Caracterização florística de uma área de contato entre Cerrado e Mata Atlântica na região sudoeste do Estado de São Paulo.

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Nicole da Silva PINTO; Natalia de Oliveira COSTA; Ana Carolina de Oliveira BARBOSA; Conceição Rodrigues de LIMA; Maria Teresa Zugliani TONIATO; Geraldo Antonio Daher Corrêa FRANCO; João Aurélio PASTORE; Osny Tadeu de AGUIAR; João Batista BAITELLO; Roque CIELO-FILHO; Silvana Cristina Pereira Muniz de SOUZA

2012-01-01

Remanescentes de vegetação nativa em áreas de contato florístico e fitogeográfico têm especial importância na conservação da biodiversidade. A EstaçãoExperimental de Itapeva – EExI apresenta os referidos atributos, pois, abriga remanescentes de Floresta Estacional Semidecidual e de Cerrado. A EExI está localizada na BaciaHidrográfica do Alto Paranapanema – BHAP, na região sudoeste do Estado de São Paulo, considerada altamente degradada e prioritária para estudos de flora e fauna. Os objetivos...

Heterogeneidade florística das fitocenoses de restingas nos estados do Rio de Janeiro e Espírito Santo, Brasil

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Luiz Fernando Silva Magnago

2011-04-01

Full Text Available Esta pesquisa teve como objetivo comparar florísticamente as formações vegetacionais que compõe o ecossistema Restinga dos Estados do Rio de Janeiro e Espírito Santo. Para isto foi realizado uma compilação de dados de levantamentos florísticos e fitossociológicos, sendo utilizado para esta análise o índice de similaridade de Jaccard, onde as interpretações se deram pela média de grupo (UPGMA. As 11 formações analisadas apresentaram uma riqueza total de 990 espécies, distribuídas em 141 famílias, sendo Fabaceae (73, Myrtaceae (59, Rubiaceae (48, Orchidaceae (44, Cyperaceae (38, Poaceae (36, Bromeliaceae (35, Euphorbiaceae (30, Asteraceae (30 as de maior riqueza. A similaridade entre as formações foi baixa, sendo o maior valor de 33%. Os resultados obtidos denotam uma alta heterogeneidade florística existente nas formações que compõe o ecossistema Restinga nos dois Estados analisados, sendo esta determinada por diferentes fatores que atuam em cada fitocenose.

Causal and causally separable processes

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Oreshkov, Ognyan; Giarmatzi, Christina

2016-09-01

The idea that events are equipped with a partial causal order is central to our understanding of physics in the tested regimes: given two pointlike events A and B, either A is in the causal past of B, B is in the causal past of A, or A and B are space-like separated. Operationally, the meaning of these order relations corresponds to constraints on the possible correlations between experiments performed in the vicinities of the respective events: if A is in the causal past of B, an experimenter at A could signal to an experimenter at B but not the other way around, while if A and B are space-like separated, no signaling is possible in either direction. In the context of a concrete physical theory, the correlations compatible with a given causal configuration may obey further constraints. For instance, space-like correlations in quantum mechanics arise from local measurements on joint quantum states, while time-like correlations are established via quantum channels. Similarly to other variables, however, the causal order of a set of events could be random, and little is understood about the constraints that causality implies in this case. A main difficulty concerns the fact that the order of events can now generally depend on the operations performed at the locations of these events, since, for instance, an operation at A could influence the order in which B and C occur in A’s future. So far, no formal theory of causality compatible with such dynamical causal order has been developed. Apart from being of fundamental interest in the context of inferring causal relations, such a theory is imperative for understanding recent suggestions that the causal order of events in quantum mechanics can be indefinite. Here, we develop such a theory in the general multipartite case. Starting from a background-independent definition of causality, we derive an iteratively formulated canonical decomposition of multipartite causal correlations. For a fixed number of settings and

Causal and causally separable processes

International Nuclear Information System (INIS)

Oreshkov, Ognyan; Giarmatzi, Christina

2016-01-01

The idea that events are equipped with a partial causal order is central to our understanding of physics in the tested regimes: given two pointlike events A and B , either A is in the causal past of B , B is in the causal past of A , or A and B are space-like separated. Operationally, the meaning of these order relations corresponds to constraints on the possible correlations between experiments performed in the vicinities of the respective events: if A is in the causal past of B , an experimenter at A could signal to an experimenter at B but not the other way around, while if A and B are space-like separated, no signaling is possible in either direction. In the context of a concrete physical theory, the correlations compatible with a given causal configuration may obey further constraints. For instance, space-like correlations in quantum mechanics arise from local measurements on joint quantum states, while time-like correlations are established via quantum channels. Similarly to other variables, however, the causal order of a set of events could be random, and little is understood about the constraints that causality implies in this case. A main difficulty concerns the fact that the order of events can now generally depend on the operations performed at the locations of these events, since, for instance, an operation at A could influence the order in which B and C occur in A ’s future. So far, no formal theory of causality compatible with such dynamical causal order has been developed. Apart from being of fundamental interest in the context of inferring causal relations, such a theory is imperative for understanding recent suggestions that the causal order of events in quantum mechanics can be indefinite. Here, we develop such a theory in the general multipartite case. Starting from a background-independent definition of causality, we derive an iteratively formulated canonical decomposition of multipartite causal correlations. For a fixed number of settings and

CACTÁCEAS NATIVAS ASSOCIADAS A FENOS DE FLOR DE SEDA E SABIÁ NA ALIMENTAÇÃO DE BORREGOS

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JOSÉ GERALDO MEDEIROS DA SILVA

2010-01-01

Full Text Available The objective of this study was to evaluate the utilization effects of two native cacti named mandacaru (Cereus jamacaru DC. and xiquexique [Pilosocereus gounellei (A. Weber ex K. Schum. Bly ex Rowl.] associated with sabiá (Mimosa caesalpiniifolia Benth. and flor de seda (Calotropis procera (Ait. R.Br. about the nutrient intake, daily weight gain, and feed conversion in sheep feedlot. Twenty Morada Nova male hair sheep with an average weight of 15.40, were allocated in a randomized block design, with four treatments and five replicates. The experimental treatments consisted of four diets (30% native cacti + 30% shrub hay + 40% concentrate, on dry matter basis: T1- xiquexique + sabiá hay; T2- xiquexique + flor de seda hay; T3- mandacaru + sabiá hay e T4- mandacaru + flor-de-seda hay. The concentrate consisted of 100.0% algaroba (Prosopis juliflora (Sw DC pods. No significant difference was observed for daily weight gain which averaged 88.77 g, and also for voluntary intakes of dry matter, organic matter, ether extract, total carbohydrates, nonfiber carbohydrates, total digestible nutrients and digestible energy in relation to g/day, %BW and g/kg0.75. Significant differences were observed for intake of water in g/day.

A proteomic and metabolomic approach for understanding the role of the flor yeast mitochondria in the velum formation.

Science.gov (United States)

Moreno-García, Jaime; García-Martínez, Teresa; Moreno, Juan; Millán, M Carmen; Mauricio, Juan Carlos

2014-02-17

Saccharomyces cerevisiae "flor" yeast shows a strong tolerance to high ethanol concentrations and develops a velum (biofilm) on the wine surface after the alcoholic fermentation of grape must. This velum remains along several years during the so called "biological aging" process in the elaboration of some special wines carried out in specific regions around the world and it contributes to the typical organoleptic characteristics of these wines. In order to grow in this condition, flor yeast has to elaborate a response where the mitochondrial function is essential. The objective of this study is to elucidate the role of the mitochondria in the response of a flor yeast, S. cerevisiae G1, growing in a controlled velum formation condition. For this purpose, proteome and metabolome were characterized by comparing data with those from an initial fermentative condition used as reference. The obtained proteomic profiles show more mitochondrial proteins related with the ethanol resistance (13), cell respiration (18), mitochondrial genome maintenance (13), and apoptosis (2) detected under the velum formation condition. Also, the finger-printing obtained by means of the exo-metabolites directly related with the quality of fermented beverages and quantified in the velum condition shows important differences from those obtained in the reference condition. Copyright © 2013 Elsevier B.V. All rights reserved.

Crescimento de girassol como flor em vaso em função de doses de paclobutrazol

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Christina da Silva Wanderley

2014-02-01

Full Text Available O girassol (Helianthus annuus L., que é comumente cultivado para produção de sementes e óleo, também apresenta potencial de uso como planta ornamental. Entretanto, seu porte elevado dificulta essa utilização, principalmente como flor em vaso. Objetivou-se neste experimento avaliar os efeitos do regulador de crescimento paclobutrazol sobre o crescimento de plantas de girassol em vaso, cultivadas em sistema hidropônico, dentro de estufa, em vasos preenchidos com sílica moída. Os dois genótipos de girassol utilizados foram BRS Oásis, com capítulo marrom e altura média de 1,85 m, e Helio 358, com capítulo amarelo e altura média de 1,45 m. As doses de paclobutrazol avaliadas foram 0; 0,5; 1; 2; 4; e 6 mg L-1 , aplicadas diretamente no substrato de sílica moída. A solução nutritiva utilizada foi a de Hoagland, e as plantas foram mantidas sob aeração constante. O delineamento experimental foi o de blocos casualizados, em esquema fatorial com cinco repetições, totalizando 60 parcelas. Avaliaram-se a altura das plantas e a massa de matéria seca de raiz, caule, folhas e de capítulos. Houve efeito do paclobutrazol sobre o crescimento das plantas. O uso do paclobutrazol na dose de 2mgL-1 reduz a altura do girassol, porém não afeta a qualidade da inflorescência, o que pode viabilizar o seu uso na produção de flores de girassol como ornamentais. A sensibilidade ao paclobutrazol é maior para o genótipo Helio 358 em relação ao genótipo BRS Oásis.

Condicionamento fisiológico de sementes de couve-flor Priming seed treatment of cauliflower seeds

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Ana Lúcia P Kikuti

2009-06-01

Full Text Available Esta pesquisa teve como objetivos definir o procedimento para o condicionamento fisiológico de sementes de couve-flor e verificar a influência do potencial fisiológico das sementes sobre os resultados desse tratamento. Seis lotes de sementes, três da cultivar Sharon e três da cultivar Teresópolis Gigante, foram submetidos ao hidrocondicionamento entre camadas de duas, quatro e seis folhas de papel toalha e ao osmocondicionamento entre camadas de quatro folhas de papel toalha umedecidas com solução de polietilenoglicol 6000 (potenciais de -0,1 e -0,2 MPa. Em todos os procedimentos os teores de água foram ajustados para 32 e 38%, para a cultivar Sharon, e 34 e 41% para a cultivar Teresópolis Gigante. Os efeitos dos tratamentos sobre a germinação e emergência das plântulas foram comparados à testemunha (sem condicionamento. O hidrocondicionamento entre quatro e seis folhas, até a obtenção dos teores de água mais elevados, beneficiou a velocidade de germinação (VG e a de emergência de plântulas (VE, nas duas cultivares. Na cultivar Sharon a VG foi de 14,6 (testemunha em comparação a 16,4 nas sementes hidrocondicionadas, para os lotes de maior e menor potencial fisiológico; paralelamente, os valores da VE aumentaram de 8,9 para 11,2 e de 7,8 para 11,6, nos lotes de menor potencial fisiológico. Para a cultivar Teresópolis Gigante, a VG e a VE foram favorecidas pelo hidrocondicionamento, independentemente do potencial fisiológico dos lotes (a VG aumentou de 16,4 para 21,4 e, a VE, de 9,5 para 13,5. Conclui-se que o hidrocondicionamento entre quatro e seis folhas de papel toalha, até a obtenção de teores de água próximos aos da emissão da raiz primária é favorável à velocidade de germinação e de emergência de plântulas em couve-flor e que o potencial fisológico inicial dos lotes pode influenciar a resposta ao condicionamento fisiológico, dependendo da cultivar ou histórico dos lotes.This research was

Análise florística e estrutura fitossociológica de um fragmento de Floresta Ombrófila Mista no município de Sertão - RSFloristic analysis and phytosociological structure of a Mixed Ombrophylous Forest

OpenAIRE

Piroli, Edson Luis; Universidade Estadual Paulista Júlio de Mesquita Filho - UNESP; Nascimento, André Rosalvo Terra; Universidade Federal de Uberlândia - UFU

2009-01-01

Neste trabalho foram estudadas a composição florística e estrutura fitossociológica de um fragmento de Floresta Ombrófila Mista no município de Sertão, RS, com área aproximada de 700 ha. A análise estrutural destaca Araucaria angustifolia (Bertol.) Kuntze, como espécie dominante, principalmente na periferia do fragmento apresentando um número relativamente menor de indivíduos no interior da floresta. Abstract This paper appraises the study of the floristic composition and phytosociological st...

Composição florística e espectro biológico na Estação Ecológica de Santa Bárbara, estado de São Paulo, Brasil Floristic composition and biological spectra in Santa Barbara Ecological Station, Brazil

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João Augusto Alves Meira Neto

2007-10-01

Full Text Available O conhecimento da flora herbáceo-subarbustiva, juntamente com o da flora lenhosa, auxilia a determinação dos padrões florísticos e permite descrever o espectro biológico com conseqüentes inferências sobre a atua��ão de fatores ambientais e históricos na vegetação. Considerando que poucos trabalhos se aprofundaram no estudo da flora herbáceo-subarbustiva de Cerrado, embora esta seja mais rica que a lenhosa, objetivou-se estudar a composição e os padrões florísticos das floras herbáceo-subarbustiva e lenhosa da Estação Ecológica de Santa Bárbara (EESB (22º 46' 30'' a 22º 50' 30''S e 49º 10' 30'' a 49º15'30'' W , 600 a 680 m de altitude, Município de Águas de Santa Bárbara, Estado de São Paulo. Visou-se, ainda, determinar o espectro biológico para efetuar análises comparativas das diferentes fitofisionomias de Cerrado dessa Unidade de Conservação. Foram encontradas 314 espécies na EESB, sendo 285 em Cerrado sensu lato. As famílias mais ricas em número de espécies foram Asteraceae, Leguminosae, Myrtaceae e Poaceae. Há uma constante ocorrência de Asteraceae, Leguminosae e Poaceae entre as famílias mais ricas, concordando com o observado nos estudos florísticos de Cerrado que incluíram os estratos lenhoso e herbáceo-subarbustivo. O espectro biológico corroborou os padrões anteriormente descritos para o Cerrado sensu lato, exceto pela maior expressão de caméfitas em relação às hemicriptófitas nas fisionomias campestres da EESB, o que pode ser efeito da proteção ao fogo nessa Unidade de Conservação.Only few surveys were carried out on woody and ground layer floras of the Brazilian Cerrado. The objective of this survey was to investigate richness, floristic patterns and biological spectra of different phytophysiognomies on both strata at Santa Bárbara Ecological Station (EESB. EESB is located in the Municipality of Águas de Santa Bárbara, São Paulo State, Brazil (22º 46' 30'' to 22º 50' 30

Composição florística e estrutura de uma unidade de manejo florestal sustentável na Floresta Nacional do Tapajós, Pará Floristic composition and structure of a sustainable forest management unit at Tapajos National Forest, Para, Brazil

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Fábio Guimarães Gonçalves

2008-01-01

Full Text Available Neste trabalho são discutidos aspectos da composição florística e da estrutura de um povoamento de floresta ombrófila densa submetido a práticas de exploração madeireira de impacto reduzido. O estudo foi conduzido numa unidade de manejo florestal com aproximadamente 3.200 ha, instalada na porção norte da Floresta Nacional do Tapajós (estado do Pará, onde foram extraídos, em média, 23,7 m³ de madeira por hectare. Para representar a variabilidade existente na área experimental, foram estabelecidas aleatoriamente seis parcelas amostrais de um hectare em diferentes quadras de exploração. As análises florístico-estruturais foram realizadas em duas escalas distintas com vistas a atender objetivos específicos: (a em nível de unidade de manejo, para uma caracterização global do povoamento florestal no qual serão baseados estudos subseqüentes; e (b em nível de parcela amostral, para subsidiar o estudo de dados de sensoriamento remoto frente às variações florístico-estruturais observadas. O conjunto de resultados obtidos indicou que a unidade de manejo florestal apresenta uma elevada diversidade florística no componente arbóreo (índice de Shannon-Weaver igual a 4,22. Observou-se que o povoamento é caracterizado pela concentração de uma grande quantidade de indivíduos e espécies em poucas famílias botânicas e por um número elevado de espécies localmente raras. A análise das variações florístico-estruturais entre parcelas amostrais evidenciou diferenças estatísticas significativas quanto à diversidade e a similaridade de espécies e quanto a valores médios de altura total. Adicionalmente, observou-se certa variabilidade nos padrões estruturais em termos de distribuição diamétrica e de valores estimados de volume comercial de madeira.In this work we discuss aspects of the floristic composition and structure of a stand of dense tropical rain forest subjected to low-impact logging practices. We conducted

Monitoreo de tortugas marinas Lepidochelis olivaceae (paslama en playa La Flor - Rivas

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Celia María Gutiérrez

1999-12-01

Full Text Available La tortuga marina Lepidochelis olivaceae desova en forma masiva, solamente en seis playas del mundo. Nicaragua cuenta con dos de estas playas en los sitios geográficos llamados ' “Chacocente", en el Departamento de Carazo y "La Flor", en San Juan del Sur. Esta especie de tortuga se caracteriza por presentar un movimiento sincronizado para su anidación en la playa, el cual se ha denominado arribadas. Durante 5 años consecutivos se realizó en el refugio de vida silvestre "La Flor", un monitoreo de la población anidante y se encontró que cada año durante el período de julio a enero, visitan esta playa aproximadamente, 3,000 a 12,000 tortugas, reportándose entre septiembre y octubre el pico más alto de la población anidante. Paralelo a este estudio, se realizó un diagnóstico rápido en las comunidades aledañas al refugio, el cual refleja que es una práctica tradicional de los pobladores, la extracción de huevos de tortuga para el consumo de la familia y para el comercio. Se considera, sin embargo, que esta práctica no representa económicamente una dependencia absoluta, ya que la población tiene otros tipos de actividades agropecuarias que contribuyen a su subsistencia.

Causally nonseparable processes admitting a causal model

International Nuclear Information System (INIS)

Feix, Adrien; Araújo, Mateus; Brukner, Caslav

2016-01-01

A recent framework of quantum theory with no global causal order predicts the existence of ‘causally nonseparable’ processes. Some of these processes produce correlations incompatible with any causal order (they violate so-called ‘causal inequalities’ analogous to Bell inequalities ) while others do not (they admit a ‘causal model’ analogous to a local model ). Here we show for the first time that bipartite causally nonseparable processes with a causal model exist, and give evidence that they have no clear physical interpretation. We also provide an algorithm to generate processes of this kind and show that they have nonzero measure in the set of all processes. We demonstrate the existence of processes which stop violating causal inequalities but are still causally nonseparable when mixed with a certain amount of ‘white noise’. This is reminiscent of the behavior of Werner states in the context of entanglement and nonlocality. Finally, we provide numerical evidence for the existence of causally nonseparable processes which have a causal model even when extended with an entangled state shared among the parties. (paper)

Florística e estrutura do componente arbóreo e análise ambiental de um fragmento de Floresta Ombrófila Mista Alto-Montana no município de Painel, SC

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Pedro Higuchi

2013-03-01

Full Text Available http://dx.doi.org/10.5902/198050988449A Floresta Ombrófila Mista Alto-Montana é uma formação pouco estudada que ocorre em altitudes acima de 1.000 m. Os objetivos deste estudo foram conhecer os padrões florísticos e estruturais do componente arbóreo de um fragmento desta floresta na região do Planalto Sul Catarinense e determinar as variáveis ambientais que influenciam esses padrões. O levantamento da composição florística e estrutural e a coleta das variáveis ambientais foram conduzidos em 50 parcelas de 200 m2. Nelas, todos os indivíduos arbóreos com CAP (circunferência medida a altura do peito ≥ 15,7 cm foram medidos (CAP e altura e identificados. Foram coletadas, em cada parcela, variáveis ambientais relacionadas às características químicas e físicas dos solos, topográficas e de cobertura do dossel. Foram calculados os parâmetros fitossociológicos e a estrutura diamétrica da comunidade e das populações com valor de importância (VI acima de 5 %. A similaridade florístico-estrutural entre as parcelas foi analisada pela NMDS (Nonmetric Multidimensional Scaling e os vetores das variáveis ambientais significativas (p < 0,05 foram plotados a posteriori. Foram identificadas 50 espécies arbóreas distribuídas em 33 gêneros e 20 famílias botânicas. As espécies com maior VI foram: Araucaria angustifolia (Bertol. Kuntze (17,32 %, Myrceugenia euosma (O.Berg D.Legrand (15,24 % e Acca sellowiana (O.Berg Burret (7,84 %. A estrutura diamétrica de toda a comunidade e das populações estudadas (exceto Dicksonia sellowiana Hook. teve distribuição próxima ao “J invertido”. A análise NMDS demonstrou maior porcentagem de argila nas parcelas com maior densidade de Araucaria angustifolia e menor porcentagem, nas parcelas com maior densidade de Dicksonia sellowiana, Inga lentiscifolia Benth. e Ocotea pulchella Mart. As parcelas de maior declividade tiveram maior densidade de Drimys brasiliensis Miers e aquelas de

Composição florística e variações morfo-pedológicas em uma área de Caatinga em Pernambuco

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Romênia Pinheiro Nascimento, Katarina

2010-01-01

Dois diferentes ambientes vegetacionais são reconhecidos para a caatinga, estando estes relacionados as unidades geológicas: matriz cristalina e as bacias e chapadas sedimentares. Contudo, não se sabe se as plantas como um todo respondem a esta repartição florística, além de, até que ponto existe a influência de fatores ambientais sobre a vegetação. Assim, este trabalho tem por objetivo analisar a composição florística através de uma análise comparativa entre doze áreas de caat...

O sentido do uso ritual da ayahuasca em trabalho voltado ao tratamento e recuperação da população em situação de rua em São Paulo

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Bruno Ramos Gomes

2011-01-01

Esta pesquisa visa a compreender o uso ritual da ayahuasca (chamado de Daime pelos participantes) na recuperação de pessoas em situação de rua pela Unidade de Resgate Flor das Águas Padrinho Sebastião, grupo situado em São Paulo. A ayahuasca é um chá feito da mistura de algumas plantas amazônicas, mais comumente o jagube e a chacrona, utilizado de forma ritual por populações indígenas e mestiças há muito tempo, e que leva a uma alteração na experiência de si e do mundo em sua ingestão. Vem ga...

Caracterização florística de bancos de sementes em sistemas de cultivo lavoura-pastagem Floristic characterization of seedbanks under Integrated crop-pasture systems

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F.S. Ikeda

2007-12-01

Full Text Available Avaliou-se o efeito de sistemas de cultivo, preparo do solo e níveis de adubação sobre a composição florística de banco de sementes no solo em áreas submetidas a três sistemas de cultivo (lavoura contínua, lavoura-pastagem-lavoura e pastagem-lavoura-pastagem, dois sistemas de preparo do solo (convencional e semeadura direta e dois níveis de adubação (manutenção e corretiva gradual, e uma área de pastagem contínua com preparo convencional e adubação corretiva gradual. Dessa forma, verificou-se que o sistema de cultivo e o sistema de preparo do solo foram os fatores mais importantes na determinação da estrutura florística dos bancos de sementes. Além disso, a adubação corretiva gradual aumentou o número de famílias e de espécies, em relação à de manutenção.The effect of cultivation systems, tillage and fertilization levels on the floristic composition of seedbanks was evaluated at three cultivation systems (continuous crop, crop-pasture-crop, pasture-crop-pasture, two tillage systems (tillage and no-tillage and two fertilization levels (corrective and maintenance, and a continuous pasture area under no-tillage and corrective fertilization. Cultivation and tillage system were the most important factors affecting the floristic structure of seedbanks. Besides, corrective fertilization increased the number of families and species in relation to maintenance fertilization.

Produtividade e qualidade da flor-de-seda em diferentes densidades e sistemas de plantio Productivity and quality of rooster tree in different planting densities and planting systems

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Maria Verônica Meira de Andrade

2008-01-01

Full Text Available Avaliou-se o efeito de dois sistemas de plantio (sem camalhão e com camalhão e de três espaçamentos (1,0 × 1,5 m; 1,5 × 2,0 m; e 2,0 × 2,0 m sobre a qualidade e a produtividade de flor-de-seda aos 60 dias de rebrotação. Utilizou-se o delineamento experimental com blocos casualizados em esquema fatorial 2 × 3 (dois sistemas de manejo do solo e três densidades de plantio com cinco repetições, em parcelas subdivididas no espaço e no tempo. Plantas escolhidas aleatoriamente foram cortadas, separadas por tratamento e analisadas quanto aos teores de matéria seca (MS, matéria orgânica (MO, cinzas, extrato etéreo (EE, proteína bruta (PB, fibra em detergente neutro (FDN, fibra em detergente ácido (FDA, celulose, hemicelulose, lignina, carboidratos não-fibrosos (CNF e carboidratos totais (CT e quanto à produtividade (kg MS/ha. Os sistemas de manejo do solo e as densidades de plantio não influenciaram a composição em MO, cinzas, FDN, EE, lignina, celulose, CNF e CT. As densidades de plantio influenciaram o teor de hemicelulose e FDA. O sistema de manejo do solo com camalhão teve efeito linear decrescente sobre o teor de PB. A maior produtividade de MS (699,72 kg/ha da flor-de-seda foi verificada no sistema de plantio mais adensado (1,0 m × 1,5 m e correspondeu a 6.666 plantas/ha.The effect of two soil handling systems was evaluated (without furrow and with furrow, three spacing (1.0 m × 1.5 m; 1.5 m × 2.0 m and 2.0 m × 2.0 m on the quality and the productivity of rooster tree 60 days after cut. It was used a split-plot (space and time factorial arrangement in a randomized block design. Factors were two soil handling systems and three planting densities (2 × 3 with five replications per treatment. Plants chosen randomly were cut, separated in accordance with treatments and analyed the contents of dry matter (DM, organic matter (OM, mineral matter (MM, ether extract (EE, crude protein (CP, neutral detergent fiber (NDF, acid

Rendimento e qualidade de sementes de arroz irrigado em função da adubação com boro

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LEITE, Ricardo Figueiredo Cavalheiro

2008-01-01

O boro é um nutriente essencial para as plantas. Suas funções estão envolvidas com o crescimento celular e o desenvolvimento da flor. Na floração, a deficiência do micronutriente reduz a macho-fertilidade em função do prejuízo à microesporogênese e ao crescimento do tubo polínico. Neste trabalho, objetivou-se definir as fases de maior sensibilidade da cultura, com o intuito de identificar épocas apropriadas para a aplicação de tratamentos corretivos de boro. A aplicação do boro, na forma de b...

Rendimento e qualidade de sementes de arroz irrigado em função da adubação com boro

OpenAIRE

Leite, Ricardo Figueiredo Cavalheiro; Schuch, Luis Osmar Braga; Amaral, Ademir dos Santos; Tavares, Lizandro Ciciliano

2011-01-01

O boro é um nutriente essencial para as plantas. Suas funções estão envolvidas com o crescimento celular e o desenvolvimento da flor. Na fase reprodutiva, a deficiência do micronutriente reduz a macho-fertilidade em função do prejuízo à microesporogênese e ao crescimento posterior do tubo polínico. Neste trabalho, objetivou-se avaliar o efeito da aplicação de boro, sobre as características agronômicas e a qualidade fisiológica das sementes de arroz produzidas. A aplicação do boro, na forma de...

Morfologia da flor, fruto e plântula de Victoria amazonica (Poepp. J.C. Sowerby (Nymphaeaceae Morphology of flower, fruit and seedling of Victoria amazonica (Poepp. J.C. Sowerby (Nymphaeaceae

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Sônia Maciel da Rosa-Osman

2011-03-01

Full Text Available Victoria amazonica (Poepp. J.C. Sowerby é uma hidrófita que ocorre nas várzeas de águas brancas e igapós da Bacia Amazônica e na Bacia do rio Paraguai. A morfologia da flor, fruto e plântula/"tirodendro" é objeto do presente trabalho. O material botânico foi coletado em Parintins e Manaus, estado do Amazonas, Brasil. A análise morfológica foi feita em material fresco e fixado em FAA 50. O desenvolvimento das plântulas foi realizado no escuro em frascos com água com teor reduzido de oxigênio. As flores possuem pedicelo longo e são hemicíclicas, diclamídeas, monoclinas e com antese vespertina. Os frutos são carnosos, indeiscentes, com pseudossincarpia. As sementes apresentam arilo que atua na dispersão pela água. As plântulas se desenvolvem em condições de hipoxia e apresentam um cotilédone exposto acicular. O "tirodendro" apresenta eofilos com heterofilia. As flores apresentam caracteres morfológicos básicos da família, a definição do tipo de fruto exige estudo ontogenético e a heterofilia é um caráter típico de plântulas/"tirodendros"de Nymphaeaceae.Victoria amazonica (Poepp. J.C. Sowerby is a hydrophyte that occurs in the white water leas and igapos of the Amazonian and Paraguay Basin. The flower, fruit and seedling/"tirodendro" morphology is the object of the present work. The botanical material was collected at Parintins and Manaus, Amazonian state, Brazil. The morphological analysis was made in both fresh and fixed material. The seedling development was accomplished in flasks with water containing little oxygen and maintained in the darkness. Flowers present long pedicel and they are hemicyclic, dichlamydeous, bisexual with vespertine anthesis. Fruits are fleshy, indehiscent with pseudo-syncarpy. Seeds present aril that acts in the water dispersion. Seedlings grow in hypoxy conditions and they present an acicular and exposed cotyledon. The "tirodendro" stage presents eophylls with heterophylly. Flowers

O aumento da lucratividade expande a acumulação de capital? Uma análise de causalidade de Granger para países da OCDE Does increasing profitability rise capital accumulation? A Granger causality analysis on OECD countries

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Adalmir Marquetti

2009-12-01

Full Text Available O objetivo deste trabalho é testar a hipótese clássico-marxiana de ligação causal entre a taxa de lucro e a taxa de acumulação de capital para um conjunto de 20 países da OCDE. A metodologia utilizada baseia-se no procedimento proposto por Toda e Yamamoto (1995 para testar a hipótese de não causalidade de Granger. A especificação de teste empregada, derivada a partir da equação de Cambridge, envolve três variáveis: a taxa de lucro, a taxa de acumulação e a taxa de investimento. A consideração da variável investimento permite comparações entre as tradições clássico-marxiana e pós-keynesianas. Os resultados para a Austrália, a Dinamarca, os eua, a Finlândia e a Irlanda são consistentes com a concepção clássico-marxiana. Por outro lado, os resultados para o Canadá, a Coreia do Sul, a Grécia e a Suécia são parcialmente consistentes com a tradição pós-keynesiana.The purpose of this paper is to test the classical-Marxian hypothesis of causal linkages between profit rate and the accumulation of capital for a dataset of 20 OECD countries. The procedure proposed by Toda and Yamamoto (1995 to test for the Granger non-causality hypotheses is employed in the statistical procedure. The test specification, derived from the Cambridge equation, involve three variables: profit rate, accumulation of capital and investment rate. The consideration of the investment rate allows a comparison between the classical-Marxian and the post-Keynesian traditions. For the cases of Australia, Denmark, usa, Finland and Ireland, the results provide empirical support for the classical-Marxian conception. On the other hand, in the cases of Canada, South Korea, Greece and Sweden, the results support the post-Keynesian tradition.

Intestinal digestibility of protein of adapted forages and by-products in Brazilian Northeast by three-steps technique Digestão intestinal da proteína de forrageiras e co-produtos da agroindústria produzidos no Nordeste Brasileiro por intermédio da técnica de três estágios

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José Gilson Lousada Regadas Filho

2010-06-01

Full Text Available It was aimed to estimate the intestinal digestibility (ID of rumen-undegradable protein (RUDP of several feeds by a three-steps procedure. The evaluated forages were algaroba (Prosopis juliflora, canafístula (Pithecellobium multiflorum, flor-de-seda (Calotropis procera, jitirana (Ipomea sp., juazeiro (Ziziphus joazeiro, mata-pasto (Senna obtusifolia, sabiá (Mimosa caesalpiniaefolia Benth, palma gigante (Opuntia ficus indica and xique-xique (Cereus gounellei, and the agroindustry byproducts were pineapple (Ananas comosus L., barbados cherry (Malpighia emarginata, cashew (Anacardium occidentale, coconut (Cocos nucifera L., melon (Cucumis melo, passion fruit (Passiflora eduli, grape (Vitis labrusca and anatto seeds (Bixa orellana L.. The feeds were incubated in rumen during 16 hours to determine the RUDP, and the residue was submitted to the digestion with pepsin solution during one hour, and pancreatic solution during 24 hours at 38ºC, those residues were analyzed for total nitrogen. The estimative of RUDP forage ranged from 13.37 to 83.6%, and the RUDP by-product ranged from 39.14 to 89.06%. The intestinal digestion of RUDP of the forages ranged from 26.09 to 80.68%, while for by-products varied from 22.26 to 76.82%. The sabiá was the forage that presented the highest intestinal digestibility and digestive rumen-undegradable protein (RUDPd, and the flor-de-seda, the lowest digestibility; while for by-products, melon and cashew presented, respectively, the highest values for DI and RUDP. The coconut presented the lowest values for ID and RUDPd. Although, some formulation systems of diets for ruminant consider that the RUDP present constant ID, the data obtained in this work suggest variation among the different feeds.A pesquisa objetivou estimar a digestibilidade intestinal (DI da proteína não-degradada no rúmen (PNDR de alimentos por intermédio da técnica de três estágios. As forragens avaliadas foram algaroba (Prosopis juliflora

Use of a flor velum yeast for modulating colour, ethanol and major aroma compound contents in red wine.

Science.gov (United States)

Moreno, Juan; Moreno-García, Jaime; López-Muñoz, Beatriz; Mauricio, Juan Carlos; García-Martínez, Teresa

2016-12-15

The most important and negative effect of the global warming for winemakers in warm and sunny regions is the observed lag between industrial and phenolic grape ripeness, so only it is possible to obtain an acceptable colour when the ethanol content of wine is high. By contrast, the actual market trends are to low ethanol content wines. Flor yeast growing a short time under velum conditions, decreases the ethanol and volatile acidity contents, has a favorable effect on the colour and astringency and significantly changes the wine content in 1-propanol, isobutanol, acetaldehyde, 1,1-diethoxiethane and ethyl lactate. The Principal Component Analysis of six enological parameters or five aroma compounds allows to classify the wines subjected to different velum formation conditions. The obtained results in two tasting sessions suggest that the flor yeast helps to modulate the ethanol, astringency and colour and supports a new biotechnological perspective for red winemakers. Copyright © 2016 Elsevier Ltd. All rights reserved.

Estudo florístico do componente herbáceo e relação com solos em áreas de caatinga do embasamento cristalino e bacia sedimentar, Petrolândia, PE, Brasil Herbaceous floristic study and relationship with soil of crystalline shield and sedimentary basin caatinga areas at Petrolândia, Pernambuco State, Brazil

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Kleber Andrade da Silva

2009-03-01

Full Text Available Realizou-se um levantamento florístico em áreas de caatinga do embasamento cristalino e de bacia sedimentar, em Petrolândia, Pernambuco, objetivando-se identificar diferenças na composição, hábito e forma de vida das herbáceas entre as duas áreas. Foram coletadas amostras de solo nas profundidades de 0 a 20 cm e de 20 a 40 cm. Foram estabelecidas 100 parcelas de 1×1 m em cada área e coletadas todas as espécies herbáceas. De modo geral, o solo da área do embasamento cristalino foi mais fértil, raso, com maior capacidade de reter água e maior porcentagem de argila. Os números de famílias, gêneros e espécies das áreas da bacia sedimentar e do embasamento cristalino foram 32, 62 e 78 e 31, 53 e 69, respectivamente. A similaridade florística entre as áreas foi alta (75%. A análise de agrupamento mostrou que os arranjos florísticos entre as parcelas amostradas são mais semelhantes dentro de cada área que entre áreas, sugerindo a existência de grupos distintos. Tipo de solo parece não ser um fator decisivo na similaridade florística, hábito e proporção de forma de vida das herbáceas da vegetação da caatinga quando as áreas são próximas, mas pode influenciar a ocorrência e a freqüência de algumas espécies.Floristic surveys were carried out in two close caatinga areas, one on the crystalline shield and the other on a sedimentary basin, both at Petrolândia, Pernambuco, Brazil, with the objective of identifying differences between the two areas in composition, habit and life form of the herbaceous flora. One hundred 1×1 m plots were established in each area and all the herbaceous species were identified. Soil samples were collected at 0-20 and 20-40 cm depths. In general, the soil in the crystalline shield area was shallower, had greater clay content, with higher water holding capacity, and was more fertile. The number of families, genera and species in the sedimentary basin and crystalline shield areas were 32

Sensibilidade da rosa 'Osiana' ao etileno

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Delaine Cristina Cordeiro

2011-01-01

Full Text Available Os objetivos deste trabalho foram determinar a sensibilidade e as respostas da rosa cultivar Osiana (Rosa × hybrida à presença de etileno ao longo da vida pós-colheita. Para determinar a sensibilidade da flor ao etileno, hastes foram cortadas e colocadas em câmaras herméticas e em seguida tratadas por 24 horas com diferentes concentrações de etileno variando de 0,0; 0,1; 1,0; 10; 100 e 1000 µL L-1do ar no interior da câmara. A rosa teve a vida pós-colheita reduzida pelo etileno, quando exposta a concentração igual ou superior a 10 µL L-1 de etileno. As flores tratadas com no mínimo de 10 µL L-1de etileno desenvolveram necrose, murcha e abscisão prematura das pétalas ainda túrgidas. As concentrações de 0,1 e 1,0 µL L-1de etileno estimularam a abertura do botão floral durante o período de 24 horas de exposição ao etileno, sem no entanto, reduzir a vida pós-colheita. A rosa 'Osiana' pode ser classificada como uma cultivar sensível ao etileno e a concentração influência os processos estimulados.

Los sueños del poder : novela por Flor Romero de Nohra

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Julian Garavito

1979-04-01

Full Text Available La novelista colombiana, oriunda de Cundinamarca, Flor Romero de Nohra ya tiene una interesante trayectoria como periodista (fundadora y directora de la revista mujer de América, como cuentista (La Ruta de El Dorado, y como novelista. Su primera obra en este genero, Tres Kilates ocho puntos obtuvo el premio Esso en 1964, Mi Capitán Fabián Sicachá fue finalista del Premio Planeta 1967 y Triquitraques del Trópico (1972 acaba de ser traducida al francés por Antoine Berman con el título Crépitant Tropique.

Causal imprinting in causal structure learning.

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Taylor, Eric G; Ahn, Woo-Kyoung

2012-11-01

Suppose one observes a correlation between two events, B and C, and infers that B causes C. Later one discovers that event A explains away the correlation between B and C. Normatively, one should now dismiss or weaken the belief that B causes C. Nonetheless, participants in the current study who observed a positive contingency between B and C followed by evidence that B and C were independent given A, persisted in believing that B causes C. The authors term this difficulty in revising initially learned causal structures "causal imprinting." Throughout four experiments, causal imprinting was obtained using multiple dependent measures and control conditions. A Bayesian analysis showed that causal imprinting may be normative under some conditions, but causal imprinting also occurred in the current study when it was clearly non-normative. It is suggested that causal imprinting occurs due to the influence of prior knowledge on how reasoners interpret later evidence. Consistent with this view, when participants first viewed the evidence showing that B and C are independent given A, later evidence with only B and C did not lead to the belief that B causes C. Copyright © 2012 Elsevier Inc. All rights reserved.

FLO11 expression and lipid biosynthesis are required for air-liquid biofilm formation in a Saccharomyces cerevisiae flor strain.

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Zara, Giacomo; Goffrini, Paola; Lodi, Tiziana; Zara, Severino; Mannazzu, Ilaria; Budroni, Marilena

2012-11-01

Air-liquid biofilm formation is largely dependent on Flo11p and seems related to cell lipid content and composition. Here, it is shown that in the presence of cerulenin, a known inhibitor of the fatty acid synthase complex, biofilm formation is inhibited together with FLO11 transcription in a flor strain of Saccharomyces cerevisiae, while the administration of saturated fatty acids to cerulenin-containing medium restores biofilm formation and FLO11 transcription. It is also shown that, in biofilm cells, the FLO11 transcription is accompanied by the transcription of ACC1, ACS1 and INO1 key genes in lipid biosynthesis and that biofilm formation is affected by the lack of inositol in flor medium. These results are compatible with the hypothesis that the air-liquid biofilm formation depends on FLO11 transcription levels as well as on fatty acids biosynthesis. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Optimal causal inference: estimating stored information and approximating causal architecture.

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Still, Susanne; Crutchfield, James P; Ellison, Christopher J

2010-09-01

We introduce an approach to inferring the causal architecture of stochastic dynamical systems that extends rate-distortion theory to use causal shielding--a natural principle of learning. We study two distinct cases of causal inference: optimal causal filtering and optimal causal estimation. Filtering corresponds to the ideal case in which the probability distribution of measurement sequences is known, giving a principled method to approximate a system's causal structure at a desired level of representation. We show that in the limit in which a model-complexity constraint is relaxed, filtering finds the exact causal architecture of a stochastic dynamical system, known as the causal-state partition. From this, one can estimate the amount of historical information the process stores. More generally, causal filtering finds a graded model-complexity hierarchy of approximations to the causal architecture. Abrupt changes in the hierarchy, as a function of approximation, capture distinct scales of structural organization. For nonideal cases with finite data, we show how the correct number of the underlying causal states can be found by optimal causal estimation. A previously derived model-complexity control term allows us to correct for the effect of statistical fluctuations in probability estimates and thereby avoid overfitting.

Diversidad Florística de la cuenca alta del rio Tambo-Ichuña, Moquegua, Perú

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Montesinos, D.B.

2011-01-01

La diversidad florística de plantas vasculares es estudiada en la cuenca del río Tambo-Ichuña, la puna y bofedales altoandinos en los distritos de Ichuña, Ubinas y Yunga (3400 – 4700 m de altitud), provincia General Sánchez Cerro, departamento de Moquegua, Perú. La flora vascular de esta región está

Boraginaceae s.l. A. Juss. em uma área de Caatinga da ESEC Raso da Catarina, BA, Brasil Boraginaceae s.l. A. Juss. in the Caatinga of the Raso da Catarina Ecological Station, Bahia State, Brazil

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José Iranildo Miranda de Melo

2007-06-01

Full Text Available Este trabalho trata do levantamento florístico-taxonômico da família Boraginaceae em um trecho de Caatinga da Estação Ecológica Raso da Catarina, Bahia, Brasil. Foram encontrados sete espécies e três gêneros de Boraginaceae: Cordia (C. globosa (Jacq. Kunth, C. leucocephala Moric. e C. rufescens A.DC., Heliotropium (H. angiospermum Murray e Heliotropium elongatum (Lehm. I.M. Johnst. e Tournefortia (T. rubicunda Salzm. ex A.DC. e T. salzmannii DC.. São apresentadas chaves para identificação de gêneros e espécies, além de descrições, ilustrações, comentários, dados de distribuição e hábitat.A floristic-taxonomic survey of the family Boraginaceae was carried out in a fragment of Caatinga vegetation of the Raso da Catarina Ecological Station, Bahia, Brazil. Seven species and three genera of Boraginaceae were found: Cordia (C. globosa (Jacq. Kunth; C. leucocephala Moric.; C. rufescens A.DC., Heliotropium (H. angiospermum Murray; H. elongatum (Lehm. I.M. Johnst. and Tournefortia (T. rubicunda Salzm. ex A.DC.; T. salzmannii DC.. Keys to identify genera and species are presented together with descriptions, illustrations, and comments on relationships among these taxa, distribution and habitat.

Composição florística e estrutura de um trecho de floresta ombrófila densa atlântica com uso pretérito de produção de banana, no parque estadual da Pedra Branca, Rio de Janeiro, RJ

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Alexandro Solórzano

2012-06-01

Full Text Available Este estudo teve como objetivos caracterizar florística e estruturalmente um trecho de Floresta Ombrófila Densa Submontana urbana e avaliar os fatores que contribuíram para a regeneração, a partir do último uso do solo para produção de banana, há 50 anos. Para a amostragem da área foram implantadas 25 parcelas de 100 m², totalizando 0,25 ha. O critério de inclusão adotado foi diâmetro à altura do peito (DAP > 5 cm. Foram amostrados 311 indivíduos de 92 espécies, 67 gêneros e 31 famílias. A área basal total foi de 34,18 m²/ha, enquanto a densidade, de 1.244 ind./ha. As espécies mais importantes na comunidade, representando 42% do valor de importância (VI da área, foram: Aiouea saligna Meisn., Tachigali paratyensis (Vell. H.C. Lima, Ficus insipida Willd., Bathysa gymonocarpa K. Schum, Chrysophyllum flexuosum Mart., Piptadenia gonoacantha (Mart. J.F. Macbr., Piper rivinoides Kunth., Hyeronima alchorneoides Allemão, Miconia cinnamomifolia (DC. Naudin e Guarea guidonia (L. Sleumer. O elevado valor do Índice de diversidade de Shannon (H'= 4,13 nats/ind., bem como o de equabilidade (J = 0,91, compara-se aos valores referenciados para florestas conservadas e inventariadas no Sudeste brasileiro. A floresta amostrada encontra-se em processo de regeneração e representa um estágio intermediário de sucessão. O cultivo da banana, após seu abandono, permitiu a entrada de espécies com estratégias de estabelecimento e propagação em condições de pouca luminosidade. A presença de uma árvore remanescente, do gênero Ficus, está relacionada a uma crença popular que acabou influenciando a estrutura da vegetação. Dessa forma, as espécies amostradas neste estudo refletiram o uso do solo passado e a cultura local.

Causality

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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.

Causal events enter awareness faster than non-causal events

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Pieter Moors

2017-01-01

Full Text Available Philosophers have long argued that causality cannot be directly observed but requires a conscious inference (Hume, 1967. Albert Michotte however developed numerous visual phenomena in which people seemed to perceive causality akin to primary visual properties like colour or motion (Michotte, 1946. Michotte claimed that the perception of causality did not require a conscious, deliberate inference but, working over 70 years ago, he did not have access to the experimental methods to test this claim. Here we employ Continuous Flash Suppression (CFS—an interocular suppression technique to render stimuli invisible (Tsuchiya & Koch, 2005—to test whether causal events enter awareness faster than non-causal events. We presented observers with ‘causal’ and ‘non-causal’ events, and found consistent evidence that participants become aware of causal events more rapidly than non-causal events. Our results suggest that, whilst causality must be inferred from sensory evidence, this inference might be computed at low levels of perceptual processing, and does not depend on a deliberative conscious evaluation of the stimulus. This work therefore supports Michotte’s contention that, like colour or motion, causality is an immediate property of our perception of the world.

Levantamento florístico das macroalgas da baía de Sepetiba e adjacências, RJ: ponto de partida para o Programa GloBallast no Brasil Floristic survey of the macroalgae from Sepetiba bay and surrounding area, Rio de Janeiro State: starting point for the GloBallast Programme in Brazil

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Maria Teresa Menezes de Széchy

2005-09-01

Full Text Available O Porto de Sepetiba, Estado do Rio de Janeiro, foi escolhido, no Brasil, como área-piloto do projeto "Remoção de barreiras para a implementação efetiva do controle de água de lastro e medidas de gestão em países em desenvolvimento" (Programa GloBallast. Para possibilitar comparações, os seis países participantes do Programa GloBallast foram orientados a adotar a mesma metodologia para o levantamento preliminar da biota das áreas-pilotos valorizando a identificação em nível de espécie. O presente estudo teve como objetivo aplicar metodologia estabelecida pelo Centro para Pesquisa sobre Espécies Marinhas Introduzidas, da Austrália (Procedimento CRIMP, com algumas adaptações, no levantamento florístico das macroalgas de substratos consolidados naturais da área-piloto do Porto de Sepetiba. Coletas de macroalgas foram realizadas em novembro/2001, em nove locais da baía de Sepetiba e adjacências, desde a franja da região sublitorânea até cerca de -4 m de profundidade. Em cada local, seis quadrados de 0,1 m² de área foram raspados. O material foi depositado no Herbário do Instituto de Pesquisas Jardim Botânico do Rio de Janeiro (RB. Das 96 espécies identificadas (20 Chlorophyta, 16 Phaeophyta, 60 Rhodophyta, 12 não haviam sido citadas anteriormente para a área de estudo. Cladophora pellucidoidea C. Hoek, Coelothrix irregularis (Harv. Boergesen e Acrochaetium savianum (Menegh. Nägeli são ocorrências novas para o Estado. Não há indícios de que as novas ocorrências equivalem a espécies recentemente introduzidas por meio das atividades portuárias. O procedimento metodológico adotado mostrou-se eficiente, resultando em listagem de espécies comparável às de levantamentos florísticos com maior esforço amostral e complementando os dados pretéritos existentes para a baía de Sepetiba e adjacências. No entanto, ressalta-se a importância de uma reavaliação das escalas temporal e espacial da estratégia de

Composição florística, espectro biológico e fitofisionomia da vegetação de muçununga nos municípios de Caravelas e Mucuri, Bahia Floristic composition, biological spectrum and phytophysiognomy of muçununga vegetation at Caravelas and Mucuri municipalities, Bahia state, Brazil

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João Augusto Alves Meira Neto

2005-02-01

Full Text Available A pouco conhecida vegetação de muçununga ocorre em Florestas Ombrófilas Densas de Terras Baixas no norte do Espírito Santo e Sul da Bahia, em locais de solo arenoso, úmido e fofo. Este trabalho teve como objetivo realizar estudos florísticos e fitofisionômicos para uma avaliação de como interferências antrópicas influenciaram a composição e a estrutura das muçunungas de Caravelas (17º41'13''S e 39º28'24''W e Mucuri (18º10'29''S e 39º53'25''W, no Estado da Bahia. Foram realizadas incursões na vegetação para coletas botânicas e construção do espectro biológico. Foram feitos perfis em quatro diferentes estratos, em ambas as muçunungas. Na muçununga de Caravelas foram relacionadas 67 espécies de 32 famílias e na de Mucuri, 53 espécies de 31 famílias. Na listagem florística ficou evidenciada a maior riqueza da muçununga de Caravelas. Nos perfis é possível perceber maior equabilidade na distribuição dos indivíduos entre as espécies da muçununga de Caravelas que entre as espécies de Mucuri. Os impactos originários da atividade humana favoreceram as formas de vida hemicriptofítica e as lianas na muçununga de Mucuri. As espécies Baccharis trimera, Blechnum serrulatum, Imperata brasiliensis e Pteridium aquilinum são indicadoras dos impactos de passagem de fogo e pastejo bovino. Os impactos antrópicos nas muçunungas foram os principais responsáveis pela diminuição da biodiversidade nesse tipo de vegetação.Little is known about muçununga vegetation, which occurs surrounded by Tropical Rain Forests in northern Espirito Santo State and southern Bahia State, in sites with sandy and wet soils. This work had the objective of studying floristic and phytophysiognomic aspects in order to evaluate how human activity influenced the structure and composition of the muçununga vegetation of Caravelas (17o41'13''S and 39o28'24''W and Mucuri (18o10'29''S and 39o53'25''W. This work was carried out trough paths in mu

Theories of Causality

Science.gov (United States)

Jones, Robert

2010-03-01

There are a wide range of views on causality. To some (e.g. Karl Popper) causality is superfluous. Bertrand Russell said ``In advanced science the word cause never occurs. Causality is a relic of a bygone age.'' At the other extreme Rafael Sorkin and L. Bombelli suggest that space and time do not exist but are only an approximation to a reality that is simply a discrete ordered set, a ``causal set.'' For them causality IS reality. Others, like Judea Pearl and Nancy Cartwright are seaking to build a complex fundamental theory of causality (Causality, Cambridge Univ. Press, 2000) Or perhaps a theory of causality is simply the theory of functions. This is more or less my take on causality.

Composición florística de pastizales en Muy Muy y Rivas, Nicaragua

OpenAIRE

Morales, Julio; Rusch, Graciela; Casanoves, Fernando; Söderström, Lars; Rocha, Lester

2013-01-01

A pesar de ser ecosistemas manejados, surgidos de la transformación de ambientes naturales, los pastizales compuestos por especies nativas y exóticas pueden tener un papel importante en la conservación de la biodiversidad y en la prestación de servicios ecosistémicos; entre ellos, la producción de forraje, la polinización y el control biológico. El presente estudio evalúa y compara la riqueza, similitud florística y distribución de plantas en pastizales seminaturales de dos zonas ganaderas: C...

Área foliar de Zinnia elegans Jacq. em diferentes épocas de semeadura e sistemas de condução.

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Ana Christina Rossini Pinto

1996-05-01

Full Text Available No presente trabalho, estudaram-se os efeitos de épocas de semeadura e sistemas de condução sobre a área foliar de Zinnia elegans e determinaram-se equações de regressão para a estimativa da área foliar de plantas submetidas a diferentes sistemas de condução. Definiram-se três estádios de desenvolvimento da planta para coleta das folhas: anterior à visualização da gema florífera apical, com gema florífera apical visível e em floração. Em cada estádio, foram coletadas, respectivamente, 45, 50 e 140 folhas por tratamento, num experimento em blocos casualizados com cinco repetições, analisado em esquema fatorial 3 X 3 (3 épocas de semeadura e 3 sistemas de condução. Determinaram-se o comprimento ao longo da nervura principal (C, a largura máxima perpendicular à nervura principal (L e a área foliar real (AFR. Estudaram-se as relações existentes entre a área foliar real e o produto do comprimento pela largura da folha, por meio de modelos de regressão linear. Concluiu-se que a área foliar foi influenciada pela época de semeadura, no estádio anterior à visualização dagema florífera apical e no de gema florífera apical visível, e pela época de semeadura e sistema de condução, no estádio de floração plena. Embora todos os modelos de regressão obtidos fossem adequados para estimar a área foliar real, recomendam-se, pela sua simplicidade, os modelos lineares sem intercepto AFR = 0,808907 CL, para o estádio anterior à visualização da gema florífera apical, AFR = 0,814309 CL, para o estádio de gema florífera apical visível, e AFR = 0,806762 CL, para o estádio de floração plena.

Ocorrência da ferrugem da videira em Minas Gerais

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Adelica Aparecida Xavier

2012-03-01

Full Text Available A ferrugem da videira causada por Phakopsora euvitis Ono constitui-se numa ameaça às regiões produtoras de uva em função do potencial destrutivo da planta. A doença foi detectada no Brasil, pela primeira vez, em 2001. Atualmente, ela ocorre no Paraná, Mato Grosso do Sul, São Paulo, Rio Grande do Sul, Mato Grosso, Roraima, Espírito Santo e Santa Catarina. Em abril de 2010, observaram-se na estação experimental da Unimontes, Janaúba, Minas Gerais, plantas da cv. Niágara rosada com sintomas típicos da doença. A análise dos sintomas e a caracterização dos urediniósporos sésseis, levemente equinulados, com formato oval, ou elipsoide formado em urédias subepidérmicas na origem, inrompentes e com paráfises circundantes dorsalmente, levaram à diagnose de Phakopsora euvitis como o agente causal da doença. Este é o primeiro relato da doença no Estado de Minas Gerais.

La flor de mi secreto (Almodóvar, 1995: La literatura como seducción

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Martínez-Carazo, Cristina

2011-04-01

Full Text Available The multiple references to writing in Pedro Almodovar’s La flor de mi secreto (1995 have arguably made this film his most literary. Reading and writing function as the structural axis of the movie because they define the existence of the main character - Leo/Amanda Gris. But beyond the constant literary allusions, what makes the “literarity” of this film is, on the one hand, the construction of the protagonist according to literary models and on the other the exploration of her subjectivity through her writing. Leo as a character is created as a replica of the tormented writers that she admires. In their stereotypical tradition, she is an alcoholic, addicted to sleeping pills, suicidal, obsessed with her loneliness and installed in her writing as a survival space. Furthermore, the spectator accesses her subjectivity through her career as a writer because her melodramatic life gets entangled with her novels. Almodóvar projects his literary ghosts in La flor de mi secreto and in the process, subverts the parameters of literature, the canon, the gender and genre categories and the question of authorship. He also resists a stable definition of literature as art by inserting it in a filmic text, favoring a complex intertextuality which contributes to dissolving the frontiers between high and low culture and to opening a common ground for the arts.Las múltiples referencias a la escritura presentes en La flor de mi secreto (1995 han llevado a etiquetar esta película como la más literaria de Pedro Almodóvar. La lectura y la escritura funcionan como hilo conductor de la película en la medida en que articulan la existencia de la protagonista, Leo/Amanda Gris. Pero más allá de este despliegue de alusiones literarias, lo que en realidad determina la literaridad del film es, por un lado, la construcción de dicho personaje a partir de modelos literarios y por otro la exploración de su subjetividad a partir de la escritura. Leo se perfila como

Levantamento florísitico na Estação Ecológica do Tripuí, Ouro Preto, MG Floristic inventory in the Tripuí Ecological Station, Ouro Preto, MG

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Gilberto Pedralli

1997-12-01

Full Text Available Realizou-se o levantamento florístico na Estação Ecológica do Tripuí, Ouro Preto, MG (43º34'33" W e 20º23'45"S. O clima da região é do tipo mesotérmico, com inverno seco (Cwb sg. Köppen e com temperaturas médias oscilando entre 14º e 19ºC. A Estação apresenta como principais tipos vegetacionais as florestas mesófilas estacionais, o cerrado, a vegetação aquática (brejos, lagoa artificial e córregos e as formações sucessionais ('candeial'. Para o levantamento florístico utilizou-se o método de parcelas e coletas por trilhas e caminhos, sendo identificadas 101 famílias, 242 gêneros e 462 espécies. As famílias que apresentaram maior riqueza específica foram Asteraceae (10,82%, Melastomataceae (8,22%, Myrtaceae (7,14% e Rubiaceae (4,76%.A floristic inventory was carried out in Tripuí Ecological Station, Ouro Preto, Minas Gerais state (43º34'33" W and 20º23'45"S. In this region the climate, according to Koppen's classification, is Cwb, i.e., with a mild summer and a dry winter. The main vegetation types identified were semideciduous mesophytic forests, cerrado, aquatic vegetation ('brejos', artificial lake and creeks and secondary formations ('candeial'. Through the floristic inventory in plots, trails and ways were identified 101 families, 242 genera and 462 species. Asteraceae (10,82%, Melastomataceae (8,22%, Myrtaceae (7,14% and Rubiaceae (4,76% were the families with the greatest specific richness.

Composição florística de trechos florestais na borda sul-amazônica Floristic composition of forest patches in Southern Amazonia

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Natália Macedo Ivanauskas

2004-09-01

Full Text Available Este estudo apresenta a composição florística de trechos de uma faixa de vegetação de transição existente na região centro-leste do Estado de Mato Grosso, mais precisamente no município de Gaúcha do Norte (13° 10'S e 53° 15' O, onde dá-se o contato entre a Floresta Ombrófila e a Floresta Estacional. O levantamento florístico foi realizado em março de 1999 e bimestralmente a partir de agosto de 1999 até março de 2001, em excursões com duração média de 5 dias, por meio de caminhadas na borda e no interior de florestas, sendo coletadas fanerógamas em fase reprodutiva. Também foram incluídas amostras vegetativas de espécies arbustivo-arbóreas, que não floresceram ou frutificaram durante o período de amostragem, amostradas em 3ha destinados ao levantamento fitossociológico. O levantamento florístico resultou em 72 famílias, 168 gêneros e 268 espécies. Do total de espécies, 66% apresentaram hábito arbóreo e 18% foram lianas. As ervas e arbustos praticamente restringiram-se às áreas de borda ou clareiras, somando 13%. Já a flora epifítica mostrou-se pouco expressiva (1%, quando comparada ao restante da Amazônia, em conseqüência do clima regional mais seco. Hemiepífitas, parasitas e palmeiras constituíram o percentual restante. Constatou-se que 39 espécies amostradas em Gaúcha do Norte ainda não haviam sido depositadas em herbários que mantém coleções representativas da flora matogrossense, enfatizando a carência de coletas nas áreas florestais do Estado.This paper shows the floristic composition of forest patches in a zone of transition vegetation which exists in the central-east region of Mato Grosso state, more specifically in the municipality of Gaúcha do Norte (13° 10'S and 53° 15' W where it connects the tropical rain-forest and the seasonal forest. The floristic survey was performed in March 1999 and bisemesterly from August 1999 to March 2001 (during excursions of an average of five days

Causal boundary for stably causal space-times

International Nuclear Information System (INIS)

Racz, I.

1987-12-01

The usual boundary constructions for space-times often yield an unsatisfactory boundary set. This problem is reviewed and a new solution is proposed. An explicit identification rule is given on the set of the ideal points of the space-time. This construction leads to a satisfactory boundary point set structure for stably causal space-times. The topological properties of the resulting causal boundary construction are examined. For the stably causal space-times each causal curve has a unique endpoint on the boundary set according to the extended Alexandrov topology. The extension of the space-time through the boundary is discussed. To describe the singularities the defined boundary sets have to be separated into two disjoint sets. (D.Gy.) 8 refs

FLO11 gene length and transcriptional level affect biofilm-forming ability of wild flor strains of Saccharomyces cerevisiae.

Science.gov (United States)

Zara, Giacomo; Zara, Severino; Pinna, Claudia; Marceddu, Salvatore; Budroni, Marilena

2009-12-01

In Saccharomyces cerevisiae, FLO11 encodes an adhesin that is associated with different phenotypes, such as adherence to solid surfaces, hydrophobicity, mat and air-liquid biofilm formation. In the present study, we analysed FLO11 allelic polymorphisms and FLO11-associated phenotypes of 20 flor strains. We identified 13 alleles of different lengths, varying from 3.0 to 6.1 kb, thus demonstrating that FLO11 is highly polymorphic. Two alleles of 3.1 and 5.0 kb were cloned into strain BY4742 to compare the FLO11-associated phenotypes in the same genetic background. We show that there is a significant correlation between biofilm-forming ability and FLO11 length both in different and in the same genetic backgrounds. Moreover, we propose a multiple regression model that allows prediction of air-liquid biofilm-forming ability on the basis of transcription levels and lengths of FLO11 alleles in a population of S. cerevisiae flor strains. Considering that transcriptional differences are only partially explained by the differences in the promoter sequences, our results are consistent with the hypothesis that FLO11 transcription levels are strongly influenced by genetic background and affect biofilm-forming ability.

Causal universe

CERN Document Server

Ellis, George FR; Pabjan, Tadeusz

2013-01-01

Written by philosophers, cosmologists, and physicists, this collection of essays deals with causality, which is a core issue for both science and philosophy. Readers will learn about different types of causality in complex systems and about new perspectives on this issue based on physical and cosmological considerations. In addition, the book includes essays pertaining to the problem of causality in ancient Greek philosophy, and to the problem of God's relation to the causal structures of nature viewed in the light of contemporary physics and cosmology.

FLORÍSTICA DE MATA CILIAR EM SÃO MARTINHO DA SERRA, RS, BRASIL

OpenAIRE

Maria Carolina dos Santos Figueiredo

2014-01-01

Matas ciliares são formações vegetais associadas a ambientes com cursos d`água, valorizadas, principalmente, pelas funções de estabilizar as margens dos rios e permitir o fluxo gênico de espécies. O objetivo deste trabalho foi o de realizar o levantamento florístico do estrato herbáceo e do estrato arbustivo-arbóreo e de sua regeneração natural em uma mata ciliar localizada no município de São Martinho da Serra, RS, região de transição entre os Biomas Pampa e Mata Atlântica. A área de estudo ...

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

International Nuclear Information System (INIS)

Garcia-Parrado, Alfonso; Senovilla, Jose M M

2003-01-01

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

Fenologia da figueira-da-índia em Selvíria - MS Phenology of cactus pear in Selvíria - MS State, Brazil

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Daniela Mota Segantini

2010-06-01

Full Text Available A figueira-da-índia é uma cactácea de origem mexicana, com grande potencial produtivo para as condições edafoclimáticas do Brasil, porém a falta de conhecimento faz com que a cultura seja pouco cultivada. Com o objetivo de avaliar a fenologia da figueira-da-índia, o presente trabalho foi realizado em plantas com 4 anos de idade, no espaçamento de 1,0 x 2,5 m, na área experimental da Fazenda de Ensino, Pesquisa e Extensão da Faculdade de Engenharia de Ilha Solteira - UNESP, localizada no município de Selvíria - MS, de agosto de 2006 a janeiro de 2007. O delineamento experimental utilizado foi o inteiramente casualizado, com dez repetições, com uma planta por parcela experimental, ocasião em que foram avaliados a fenologia e o crescimento dos frutos. O período de emissão das gemas concentrou-se nos meses de setembro e outubro. O florescimento, ocorreu 30 dias após a emissão da gema florífera. Os frutos atingiram a maturidade fisiológica (ponto de colheita aos 66 dias após o florescimento e aos 72 dias apresentavam-se maduros, aptos para o consumo. O período de desenvolvimento dos frutos, desde a emissão da gema florífera até a maturidade fisiológica, foi de 96 dias. A curva de crescimento dos frutos foi do tipo quadrática. A cultura da figueira-da-índia pode tornar-se uma alternativa principalmente para pequenos produtores, visto que não exige grandes investimentos para sua implantação e condução, além de se adaptar bem às condições ambientais de nosso País. Seus frutos possuem excelentes preços tanto no mercado nacional como no internacional, e o aproveitamento na forma de doces e geleias pode incrementar a renda dos produtores.The cactus pear is a cactaceous with Mexican origin and great productive potential for the edaphoclimatic conditions in Brazil, but for lack of knowledge, the culture is still little cultivated. With the objective to evaluate the phenology of cactus pear, the present research was

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

International Nuclear Information System (INIS)

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 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.

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.

Causality in Science

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Cristina Puente Águeda

2011-10-01

Full Text Available Causality is a fundamental notion in every field of science. Since the times of Aristotle, causal relationships have been a matter of study as a way to generate knowledge and provide for explanations. In this paper I review the notion of causality through different scientific areas such as physics, biology, engineering, etc. In the scientific area, causality is usually seen as a precise relation: the same cause provokes always the same effect. But in the everyday world, the links between cause and effect are frequently imprecise or imperfect in nature. Fuzzy logic offers an adequate framework for dealing with imperfect causality, so a few notions of fuzzy causality are introduced.

Coincidence of flowering time and the productivity and quality of cauliflower hybrid seeds Coincidência de florescimento entre linhagens de couve-flor na produtividade e qualidade de sementes híbridas

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Marcelo Fontanetti Verdial

2001-09-01

Full Text Available The missing of flowering synchronization between the self-incompatible lines in a crop field of cauliflower hybrid seeds besides making the seed production smaller can compromise the genetic purity of them. The coincidence of the flowering time between two cauliflower lines was examined to study its effect on the productivity and quality of hybrid seeds. The treatments consisted of six different sowing dates, every fifteen days, using a self-incompatible tropical line pollinated by a winter line which does not present self-incompatibility. The following characteristics were evaluated: leaf average area and number of flowers per plant, number of siliques per plant, number and weight of seeds per plant, weight of thousand seeds and average number of seeds per silique. The germination standard test and genetic seed purity were determined for each treatment. The coincident flowering season between cauliflower lines affects directly the productivity and the genetic quality of the produced hybrid seeds. The closer the flowering time coincidence between the lines, the greater the number of seeds per silique and the smaller the percentage of non-hybrid seedlings. However, the coincidence of the flowering season between lines was found to influence physiological seed quality.A falta de sincronismo de florescimento entre as linhagens auto incompatíveis em um campo de produção de sementes híbridas de couve flor pode além de reduzir a produção de sementes comprometer a pureza genética das mesmas. Com o objetivo de estudar o efeito da coincidência de florescimento entre linhagens de couve-flor na produtividade e qualidade de sementes híbridas, foi realizado o presente experimento. Os tratamentos consistiram em seis diferentes épocas de semeadura, espaçadas a cada quinze dias, de uma linhagem de verão auto-incompatível que foi polinizada por uma linhagem de inverno que não apresenta auto-incompatibilidade. Observou-se a coincidência do

A theory of causal learning in children: causal maps and Bayes nets.

Science.gov (United States)

Gopnik, Alison; Glymour, Clark; Sobel, David M; Schulz, Laura E; Kushnir, Tamar; Danks, David

2004-01-01

The authors outline a cognitive and computational account of causal learning in children. They propose that children use specialized cognitive systems that allow them to recover an accurate "causal map" of the world: an abstract, coherent, learned representation of the causal relations among events. This kind of knowledge can be perspicuously understood in terms of the formalism of directed graphical causal models, or Bayes nets. Children's causal learning and inference may involve computations similar to those for learning causal Bayes nets and for predicting with them. Experimental results suggest that 2- to 4-year-old children construct new causal maps and that their learning is consistent with the Bayes net formalism.

Reserva biológica estadual da Praia do Sul (Ilha Grande, Estado do Rio de Janeiro: lista preliminar da flora

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Dorothy Sue Dunn de Araujo

1987-12-01

Full Text Available A Reserva Biológica Estadual da Praia do Sul está localizada na parte meridional da Ilha Grande - RJ (23º10' S.; 44º17' W.Gr., abrangendo uma área de 3600 ha. Foram identificadas nesta Reserva 5 comunidades vegetais, a saber: psamofila reptante de anteduna, mata de cordão arenoso, mata alagadiça de planície, manguezal e mata de encosta. A fitofisionomia de cada comunidade está descrita, incluindo as espécies mais comuns e a área da Reserva ocupada por cada uma. O levantamento florístico ainda incompleto constitui uma lista de cerca de 300 espécies: as 4 famílias mais importantes são: Leguminose, Rubiaceae, Orchidaceae, BromeliaceaeThe Praia do Sul State Biological Reserve is located on Ilha Grande, State oí Rio de Janeiro, Brazil (23º10' S.; 44º17' W.Gr.. Five plant communities were identified within the limits of this 3600 ha tract: creeping foredune psammophytes, beach ridge forest, coastal plain swamp forest, mangrove and montane forest. The physiognomy of each community is described, including the most common species found and the area of occurrence within the Reserve. A list of approximately 300 species has been compiled to date; the 4 most important families are: Leguminosae, Rubiaceae, Orchidaceae, Bromeliaceae

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.

A theory of causal learning in children: Causal maps and Bayes nets

OpenAIRE

Gopnik, A; Glymour, C; Sobel, D M; Schulz, L E; Kushnir, T; Danks, D

2004-01-01

The authors outline a cognitive and computational account of causal learning in children. They propose that children use specialized cognitive systems that allow them to recover an accurate "causal map" of the world: an abstract, coherent, learned representation of the causal relations among events. This kind of knowledge can be perspicuously understood in terms of the formalism of directed graphical causal models, or Bayes nets. Children's causal learning and inference may involve computatio...

Florística e estrutura de um fragmento de Floresta Ombrófila Mista no Planalto Catarinense

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Carine Klauberg

2010-04-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2010v23n1p35 O Planalto Catarinense constitui-se em uma importante região estratégica para estudos referentes à conservação, em função da ocorrência de remanescentes de Floresta Ombrófila Mista e por ser uma área de recarga e afloramento do aquífero Guarani. Com o objetivo de avaliar a similaridade florística entre diferentes áreas amostrais e descrever a estrutura do componente arbóreo, foram alocadas, no Parque Natural Municipal de Lages, SC, quatro parcelas permanentes (40 x 40m e cada uma foi dividida em 16 unidades amostrais de 10 x 10m. Árvores com DAP ≥ 5cm foram mapeadas, marcadas e mensuradas. Os espécimes foram coletados, identificados e depositados em herbário. Foram amostradas 46 espécies distribuídas em 39 gêneros e 27 famílias. As famílias mais ricas em espécies foram Myrtaceae, Lauraceae, Salicaceae e Sapindaceae as quais apresentaram alta densidade, assim como Dicksoniaceae e Clethraceae. Sete espécies somaram mais de 60% do total de indivíduos amostrados. A diversidade específica (H’ foi de 3,05 nats.ind-1 (J’= 0,81. A similaridade entre as parcelas foi de 32 a 44%, indicando baixa semelhança entre as parcelas estudadas. A distribuição espacial da maioria das espécies é classificada como agregada, conforme o índice de Morisita. Esta floresta é considerada rica e diversa, com espécies arbóreas ameaçadas de extinção tais como Araucaria angustifolia e Dicksonia sellowiana. Devido à grande importância ecológica para a flora e fauna local e o processo de fragmentação na região, este remanescente florestal deve ser protegido e conservado, visto que ainda ocorrem interferências antrópicas negativas.

Comparação florística e estrutural de duas florestas de várzea no estuário amazônico, Pará, Brasil

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Fábio de Jesus Batista

2011-04-01

Full Text Available O objetivo deste trabalho foi conhecer e comparar a composição florística e a estrutura de duas áreas de florestas de várzea localizadas na reserva extrativista Chocoaré-Mato Grosso, Santarém Novo-PA. O inventário florístico abrangeu 1,5 ha em parcelas de 10 x 100 m, distribuídas na área 1 (1,0 ha e área 2 (0,5 ha. Foram identificados os indivíduos arbóreos com circunferência a 1,3 m altura do solo (CAP > 30 cm e demonstrada a riqueza, área basal e o IVI (Índice de Valor de Importância para cada área. A relação entre as áreas foi realizada por meio da similaridade de espécies, densidade, área basal, análise de agrupamento e espécies indicadoras. Na área 1, ocorreram 613 ind.ha-1 (26,67 m².ha-1 distribuídos em 17 famílias, 33 gêneros e 34 espécies com Euterpe oleracea, Enterolobium maximum, Symphonia globulifera, Pterocarpus amazonicus e Virola surinamensis apresentando os maiores IVI's e a área 2 com 744 ind.ha-1 (35,34 m².ha-1 em 13 famílias, 24 gêneros e 26 espécies com Mauritia flexuosa, Euterpe oleracea, Virola surinamensis, Tapirira guianensis e Inga thibaudiana com os maiores IVI's. As áreas registraram baixas similaridades entre si (0,18 e tanto a densidade quanto a área basal foram superiores na área 2. O agrupamento separou as áreas entre si e das 51 espécies, apenas 15 foram indicadoras. Conclui-se que, as florestas apresentaram baixa riqueza com pouca semelhança entre as populações arbóreas e as espécies indicadoras ocorreram nas áreas 1 e 2.

Repeated causal decision making.

Science.gov (United States)

Hagmayer, York; Meder, Björn

2013-01-01

Many of our decisions refer to actions that have a causal impact on the external environment. Such actions may not only allow for the mere learning of expected values or utilities but also for acquiring knowledge about the causal structure of our world. We used a repeated decision-making paradigm to examine what kind of knowledge people acquire in such situations and how they use their knowledge to adapt to changes in the decision context. Our studies show that decision makers' behavior is strongly contingent on their causal beliefs and that people exploit their causal knowledge to assess the consequences of changes in the decision problem. A high consistency between hypotheses about causal structure, causally expected values, and actual choices was observed. The experiments show that (a) existing causal hypotheses guide the interpretation of decision feedback, (b) consequences of decisions are used to revise existing causal beliefs, and (c) decision makers use the experienced feedback to induce a causal model of the choice situation even when they have no initial causal hypotheses, which (d) enables them to adapt their choices to changes of the decision problem. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

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

CRESCIMENTO RADICULAR DE MUDAS DE COUVE-FLOR PRODUZIDAS EM DIFERENTES SUBSTRATOS DE PRODUÇÃO AGROECOLOGICA

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Julio Cesar Gradice Saluci

2017-05-01

Full Text Available Este trabalho teve como objetivo avaliar o desempenho de mudas de couve flor, semeadas em diferentes substratos: e concentrações  orgânicas formuladas a partir de matéria prima disponível na região. O estudo foi desenhado no delineamento inteiramente casualizado com sete repetições considerando uma planta por repetição, em esquema fatorial 4x4, quatro substratos e quatro concentrações os tratamentos foram quatro tipos de substratos sendo um comercial comumente utilizado para produção de mudas de hortaliças e três orgânicos de produção agroecológica, ambos produzidos no setor de agroecologia do ifes-campus de alegre, sendo: S1- Composto orgânico produzido pelo processo de compostagem de restos de poda de jardim e esterco bovina fresco, de acordo com a metodologia de (SOUZA et al., 2013; S2- Vermicomposto produzido com o composto orgânico no qual foi inserido minhocas Eisenia foetida para realizar o processo de vermicompostagem e S3 - Composto orgânico  com cinzas de madeira + restos de poda de jardins + esterco bovino, compostado em sistemas de pilhas. As concentrações foram 25, 50, 75 e 100% de substrato completados com volumoso de terra de barranco característica de horizonte c, completados em volumes. Os substratos  orgânicos apresentaram bons desenvolvimento de raiz para as mudas de couve flor.

Non-Causal Computation

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Ämin Baumeler

2017-07-01

Full Text Available Computation models such as circuits describe sequences of computation steps that are carried out one after the other. In other words, algorithm design is traditionally subject to the restriction imposed by a fixed causal order. We address a novel computing paradigm beyond quantum computing, replacing this assumption by mere logical consistency: We study non-causal circuits, where a fixed time structure within a gate is locally assumed whilst the global causal structure between the gates is dropped. We present examples of logically consistent non-causal circuits outperforming all causal ones; they imply that suppressing loops entirely is more restrictive than just avoiding the contradictions they can give rise to. That fact is already known for correlations as well as for communication, and we here extend it to computation.

Composição florística e estrutura do componente arbóreo de uma Floresta Paludosa na planície costeira da bacia do rio Itaguaré, Bertioga, SP, Brasil. Floristic composition andstructure of an arboreal component of the Paludal Forest in the coastal plain of the Itaguaré river basin, Bertioga (São Paulo state, Brazil

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Celia Regina de Gouveia SOUZA

2012-06-01

Full Text Available As Florestas Paludosas costeiras ou “caxetais” ocorrem no Domínio Atlântico, em geral associadas a depressões paleolagunares, cujos terrenos são permanentemente encharcados. Essas florestas se caracterizam por apresentar elevada densidade de indivíduos da espécie Tabebuia cassinoides (Lam. DC., conhecida popularmente por “caxeta”. O presente estudo foi desenvolvido em uma Floresta Paludosa situada na planície costeira do rio Itaguaré, município de Bertioga, Baixada Santista, Estado de São Paulo. A composição florística e a estrutura fitossociológica foram investigadas através da amostragem por parcelas, sendo incluídos todos os indivíduos com 10 cm ou mais de diâmetro a 1,3 m de altura do peito (DAP. Foram registradas 20 espécies e 11 famílias botânicas, resultando em uma densidade total de 450 ind./ha-1. A família com maior riqueza de espécies foi Myrtaceae, com quatro espécies. A análise de similaridade indicou dois grupos florísticos. Tabebuia cassinoides foi, de fato, a espécie mais importante, apresentando grande densidade e dominância de indivíduos, o que reforça sua posição de espécie indicadora deste tipo vegetacional, conforme difundido na literatura. The coastal Paludal Forest or “Caxetal” occurs on the Atlantic Domain, associated to wetlands within palaeolagoonal depressions. It is characterized by a high density of individuals of Tabebuia cassinoides (Lam. DC., which is popularly known as “caxeta”. A Paludal Forest located in the Itaguaré river coastal plain, in the municipality of Bertioga, Santos Lowland, São Paulo State, Brazil was studied. The floristic composition and phytossociological structure was investigated through a plot method including all individuals with diameter at 1.3 m (DBH ≥ 10 cm. A total of 20species and 11 botanic families were sampled, resulting in a total density of 450 ind./ha-1. Myrtaceae showed the highest species richness. The similarity index indicated

Causality re-established.

Science.gov (United States)

D'Ariano, Giacomo Mauro

2018-07-13

Causality has never gained the status of a 'law' or 'principle' in physics. Some recent literature has even popularized the false idea that causality is a notion that should be banned from theory. Such misconception relies on an alleged universality of the reversibility of the laws of physics, based either on the determinism of classical theory, or on the multiverse interpretation of quantum theory, in both cases motivated by mere interpretational requirements for realism of the theory. Here, I will show that a properly defined unambiguous notion of causality is a theorem of quantum theory, which is also a falsifiable proposition of the theory. Such a notion of causality appeared in the literature within the framework of operational probabilistic theories. It is a genuinely theoretical notion, corresponding to establishing a definite partial order among events, in the same way as we do by using the future causal cone on Minkowski space. The notion of causality is logically completely independent of the misidentified concept of 'determinism', and, being a consequence of quantum theory, is ubiquitous in physics. In addition, as classical theory can be regarded as a restriction of quantum theory, causality holds also in the classical case, although the determinism of the theory trivializes it. I then conclude by arguing that causality naturally establishes an arrow of time. This implies that the scenario of the 'block Universe' and the connected 'past hypothesis' are incompatible with causality, and thus with quantum theory: they are both doomed to remain mere interpretations and, as such, are not falsifiable, similar to the hypothesis of 'super-determinism'.This article is part of a discussion meeting issue 'Foundations of quantum mechanics and their impact on contemporary society'. © 2018 The Author(s).

Florística das espécies arbóreas de quatro fragmentos de Floresta Estacional Semidecídua Montana na Fazenda Dona Carolina (Itatiba/Bragança Paulista, São Paulo, Brasil. Floristic of tree species of four fragments of semi-deciduous Seasonal Montana Forest in Dona Carolina Farm (Itatiba/Bragança Paulista, São Paulo, Brazil.

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Roberta Macedo CERGUEIRA Leonardo Dias MEIRELES

2008-06-01

Full Text Available Realizou-se um levantamento florísticoem quatro fragmentos de Floresta EstacionalSemidecídua Montana na Fazenda Dona Carolina,localizada nos municípios de Itatiba e Bragança Paulista,São Paulo, Brasil (22º 56’ 16” S e 46º 42’ 02” W.A Fazenda localiza-se dentro da unidademorfoescultural do Planalto Atlântico, com climaCfa e altitudes entre 775 e 974 m. As espéciesarbóreas de altura 2 metros foram coletadas eidentificadas. Foram amostradas 157 espécies,distribuídas em 109 gêneros e 41 famílias. As famíliasFabaceae (24 spp., Myrtaceae (15 spp., Lauraceae(9 spp. e Meliaceae (9 spp. foram as mais ricasem espécies. A similaridade florística da área emestudo com Florestas Estacionais SemidecíduasMontanas e Submontanas do Estado de São Paulofoi verificada através do índice de Jaccard e dométodo de agrupamento por média de grupos(UPGMA. Uma Twinspan foi realizada paraverificar quais espécies caracterizariam os gruposformados. A área estudada apresentou altasimilaridade florística com os fragmentos localizadosno município de Campinas, não se agrupando como fragmento florestal amostrado no mesmomunicípio. A restauração de áreas degradadas e aconservação de fragmentos localizados nessa regiãodevem, então, considerar a composição florísticados fragmentos adjacentes.A floristic survey was carried out in fourfragments of Semideciduous Seasonal MontaneForest in Dona Carolina Farm, located in themunicipalities of Itatiba and Bragança Paulista,São Paulo, Brazil (22º 56’ 16” S e 46º 42’ 02” W.The Farm is within the Atlantic Plateaumorphosculptural unit, with climate Cfa, between775 and 974 m elevation. Only tree species 2 meters high were collected and identified.A total of 157 species distributed in 109 generaand 41 families were sampled. Fabaceae (24species, Myrtaceae (15, Lauraceae (9 and Meliaceae(9 were the richest families. The floristicsimilarity between the studied area and other Semideciduous

Levantamento florístico e fitofisionomia da lagoa Figueira e seu entorno, planície alagável do alto rio Paraná, Porto Rico, Estado do Paraná, Brasil - DOI: 10.4025/actascibiolsci.v25i1.2091 Floristic survey and phytophysiognomy of the Figueira pond in the upper Paraná River floodplain, in Porto Rico, state of Paraná, Brazil - DOI: 10.4025/actascibiolsci.v25i1.2091

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Maria Conceição de Souza

2003-04-01

Full Text Available Foi realizada uma caracterização botânica da lagoa Figueira (planície alagável do alto rio Paraná, Porto Rico, Estado do Paraná, Brasil, a 22o45’36’’S e 53ol5’56’’W, empregando-se levantamentos florísticos e perfis fitofisionômicos em diferentes períodos fluviométricos, além de uma carta batimétrica e análise do solo. O levantamento florístico resultou no reconhecimento de 36 famílias, 75 gêneros e 89 espécies. As famílias de maior riqueza específica foram Poaceae (14 espécies, seguida por Cyperaceae e Euphorbiaceae (oito cada. O porte predominante pertenceu ao herbáceo (79,78% das espécies e, quanto à forma biológica, houve predominância das terrestres (50,56% e das anfíbias (37,08%. A fitofisionomia, com predominância de herbáceas, apresenta diferenciações entre as margens e ao longo da lagoa, havendo uma considerável diminuição da cobertura vegetal no período de águas altas. Essa lagoa foi considerada um corpo de água raso, com solo tipo argilosoA botanical characterization of the Figueira pond (Upper Paraná River floodplain, in Porto Rico, State of Paraná, Brazil, at 22o45’36’’ S and 53ol5’56’’ W has been carried out using floristic surveys and phytophysiognomic profiles, in different water periods, together with a bathymetric chart and a soil analysis. The floristic survey resulted in 36 families, 75 genera and 89 species. The families with more specific richness were Poaceae (14 species, followed by Cyperaceae and Euphorbiaceae (eight each. The highest habit incidence belonged to the herbaceous (79,78% of the species and, concerning the biological form, there was predominance of the terrestrial (50,56% and amphibious ones (37,08%. The phytophysiognomy, with predominance of herbaceous, shows differentiation between the banks and along the pond, with a considerable decrease of the vegetal covering in the high water periods. This pond was considered a shallow body of water, with

Further properties of causal relationship: causal structure stability, new criteria for isocausality and counterexamples

International Nuclear Information System (INIS)

Garcia-Parrado, Alfonso; Sanchez, Miguel

2005-01-01

Recently (Garcia-Parrado and Senovilla 2003 Class. Quantum Grav. 20 625-64) the concept of causal mapping between spacetimes, essentially equivalent in this context to the chronological map defined in abstract chronological spaces, and the related notion of causal structure, have been introduced as new tools to study causality in Lorentzian geometry. In the present paper, these tools are further developed in several directions such as (i) causal mappings-and, thus, abstract chronological ones-do not preserve two levels of the standard hierarchy of causality conditions (however, they preserve the remaining levels as shown in the above reference), (ii) even though global hyperbolicity is a stable property (in the set of all time-oriented Lorentzian metrics on a fixed manifold), the causal structure of a globally hyperbolic spacetime can be unstable against perturbations; in fact, we show that the causal structures of Minkowski and Einstein static spacetimes remain stable, whereas that of de Sitter becomes unstable, (iii) general criteria allow us to discriminate different causal structures in some general spacetimes (e.g. globally hyperbolic, stationary standard); in particular, there are infinitely many different globally hyperbolic causal structures (and thus, different conformal ones) on R 2 (iv) plane waves with the same number of positive eigenvalues in the frequency matrix share the same causal structure and, thus, they have equal causal extensions and causal boundaries

A quantum causal discovery algorithm

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Giarmatzi, Christina; Costa, Fabio

2018-03-01

Finding a causal model for a set of classical variables is now a well-established task—but what about the quantum equivalent? Even the notion of a quantum causal model is controversial. Here, we present a causal discovery algorithm for quantum systems. The input to the algorithm is a process matrix describing correlations between quantum events. Its output consists of different levels of information about the underlying causal model. Our algorithm determines whether the process is causally ordered by grouping the events into causally ordered non-signaling sets. It detects if all relevant common causes are included in the process, which we label Markovian, or alternatively if some causal relations are mediated through some external memory. For a Markovian process, it outputs a causal model, namely the causal relations and the corresponding mechanisms, represented as quantum states and channels. Our algorithm opens the route to more general quantum causal discovery methods.

Pluralidade do nexo causal em acidente de trabalho/doença ocupacional: estudo de base legal no Brasil

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Lenz Alberto Alves Cabral

2018-02-01

Full Text Available Resumo Introdução: a determinação do nexo causal do acidente de trabalho/doença ocupacional é de suma importância, pois sua análise envolve fatores ideológicos, éticos, humanísticos e legais, sendo realizada nos âmbitos trabalhista, previdenciário e cível. Objetivo: identificar e sistematizar atos normativos legais para subsidiar a compreensão interpretativa do nexo causal entre o sinistro laboral e o trabalho, nos âmbitos trabalhista, previdenciário e cível. Métodos: ensaio crítico-reflexivo, com base em levantamento e sistematização da legislação trabalhista brasileira que dá suporte ao estabelecimento do nexo causal no acidente do trabalho pelos atores sociais legalmente responsáveis por sua determinação. Resultados: são identificadas três modalidades de nexo causal: trabalhista, pelos Serviços Especializados de Engenharia de Segurança e Medicina do Trabalho (SESMT; previdenciário, pelo Instituto Nacional do Seguro Social (INSS; e cível, pela Justiça do Trabalho. A Lei nº 8.213/1991 é referência comum para as três instituições; outros atos legais normativos são específicos no âmbito de cada instituição: as Normas Regulamentadoras do Trabalho (SESMT; a Instrução Normativa 31 (INSS e o Código Civil (Justiça do Trabalho. Conclusão: o uso correto da legislação facilita o estabelecimento do elo entre o acidente e o trabalho, auxiliando na sua compreensão, padronização, diminuição de conflitos e aumento da notificação.

Epidemiological causality.

Science.gov (United States)

Morabia, Alfredo

2005-01-01

Epidemiological methods, which combine population thinking and group comparisons, can primarily identify causes of disease in populations. There is therefore a tension between our intuitive notion of a cause, which we want to be deterministic and invariant at the individual level, and the epidemiological notion of causes, which are invariant only at the population level. Epidemiologists have given heretofore a pragmatic solution to this tension. Causal inference in epidemiology consists in checking the logical coherence of a causality statement and determining whether what has been found grossly contradicts what we think we already know: how strong is the association? Is there a dose-response relationship? Does the cause precede the effect? Is the effect biologically plausible? Etc. This approach to causal inference can be traced back to the English philosophers David Hume and John Stuart Mill. On the other hand, the mode of establishing causality, devised by Jakob Henle and Robert Koch, which has been fruitful in bacteriology, requires that in every instance the effect invariably follows the cause (e.g., inoculation of Koch bacillus and tuberculosis). This is incompatible with epidemiological causality which has to deal with probabilistic effects (e.g., smoking and lung cancer), and is therefore invariant only for the population.

Discrete causal theory emergent spacetime and the causal metric hypothesis

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Dribus, Benjamin F

2017-01-01

This book evaluates and suggests potentially critical improvements to causal set theory, one of the best-motivated approaches to the outstanding problems of fundamental physics. Spacetime structure is of central importance to physics beyond general relativity and the standard model. The causal metric hypothesis treats causal relations as the basis of this structure. The book develops the consequences of this hypothesis under the assumption of a fundamental scale, with smooth spacetime geometry viewed as emergent. This approach resembles causal set theory, but differs in important ways; for example, the relative viewpoint, emphasizing relations between pairs of events, and relationships between pairs of histories, is central. The book culminates in a dynamical law for quantum spacetime, derived via generalized path summation.

Causal Analysis After Haavelmo

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Heckman, James; Pinto, Rodrigo

2014-01-01

Haavelmo's seminal 1943 and 1944 papers are the first rigorous treatment of causality. In them, he distinguished the definition of causal parameters from their identification. He showed that causal parameters are defined using hypothetical models that assign variation to some of the inputs determining outcomes while holding all other inputs fixed. He thus formalized and made operational Marshall's (1890) ceteris paribus analysis. We embed Haavelmo's framework into the recursive framework of Directed Acyclic Graphs (DAGs) used in one influential recent approach to causality (Pearl, 2000) and in the related literature on Bayesian nets (Lauritzen, 1996). We compare the simplicity of an analysis of causality based on Haavelmo's methodology with the complex and nonintuitive approach used in the causal literature of DAGs—the “do-calculus” of Pearl (2009). We discuss the severe limitations of DAGs and in particular of the do-calculus of Pearl in securing identification of economic models. We extend our framework to consider models for simultaneous causality, a central contribution of Haavelmo. In general cases, DAGs cannot be used to analyze models for simultaneous causality, but Haavelmo's approach naturally generalizes to cover them. PMID:25729123

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.

Controle biológico de Mycosphaerella fijiensis Morelet agente causal da sigatoka-negra da bananeira (Musa spp.) com Trichoderma spp.

OpenAIRE

Cavero, Poholl Adan Sagratzki

2011-01-01

O principal problema fitossanitário da cultura da bananeira no Brasil e também em outros países é a sigatoka-negra, causada pelo fungo Micosphaerella fijiensis Morelet, que pode ocasionar perdas de até 100% da produção. A medida mundialmente mais utilizada no controle deste problema em bananais comerciais têm sido pulverizações com fungicidas. Na Amazônia, o uso de fungicidas para o controle da sigatoka-negra torna-se econômica e ecologicamente inviável, face aos custos e aos impactos ambient...

Aspectos florísticos da vegetação de restinga no litoral de Pernambuco Floristics aspects of restinga vegetation in the coast of Pernambuco - Brazil

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Ana Cláudia Sacramento

2007-12-01

Full Text Available As zonas costeiras acolhem quadros de alta riqueza e relevância ecológica que as qualificam como importante ecossistema para conservação. O objetivo deste estudo foi listar as espécies que compõem a restinga da praia do Paiva e descrever a sua fisionomia. A área de restinga compreende 147 ha, situa-se no Município do Cabo de Santo Agostinho, PE, sob as coordenadas 08º07'30"S e 35º00'55"W. As coletas florísticas foram realizadas durante 28 meses, em todos os estratos. O solo foi classificado como Neossolo Quartzarênico; foram determinadas duas fisionomias: a floresta não-inundável e o fruticeto aberto não-inundável. Foram listadas 124 espécies, distribuídas em 103 gêneros e 55 famílias. As famílias com maior número de espécies foram Myrtaceae, com 11 espécies, Cyperaceae (10, Fabaceae (8, Euphorbiaceae (7, Rubiaceae (6 e Asteraceae (5. As espécies Anacardium occidentale, Tapirira guianensis, Chamaecrista ramosa, Protium heptaphyllum, Byrsonima sericea, Myrcia rotundifolia e Marlierea schotti são encontradas na maioria das restingas do Nordeste. No entanto, devido à incipiência dos estudos na Região não foram verificadas espécies endêmicas.The high biodiversity and richness of the coastal zone make it an important ecosystem to be preserved. The aim of this study is to list the species composition of the restinga area (147 ha. of Paiva beach, in Cabo de Santo Agostinho-Pernambuco (08º07'30"S and 35º00'55"W and describe the physiognomies. Floristic survey was carried out for 28 months for all strata. The soil was classified as Quartzarenic Neosoil and two physiognomies were determined: unflooded forest and unflooded open shrubby vegetation. One hundred-twenty-four species were recorded, distributed in 103 genera and 55 families. The families with the highest number of species were: Myrtaceae (11, Cyperaceae (10, Fabaceae (8, Euphorbiaceae (7, Rubiaceae (6 and Asteraceae (5. Anacardium occidentale, Byrsonima sericea

Estudio florístico de los páramos de pajonal meridionales de Ecuador

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Jesús Izco

2013-04-01

Full Text Available El presente trabajo es un estudio de la flora de los páramos de pajonal seriales de distintos macizos montañosos de los Andes del Sur de Ecuador (provincias de Azuay y Loja comprendidos entre los 2850 m y 3635 m. Fueron identificadas 43 familias de plantas vasculares, 120 géneros y 216 especies. La flora local es comparada con la de otros páramos de pajonal andinos; la riqueza florística (géneros y especies es analizada por tramos altitudinales y se establece la flora característica de cada tramo del territorio estudiado. De forma complementaria, discutimos las influencias biogeográficas de la flora de los páramos de pajonal.

Ecologia da polinização da amoreira-preta (Rubus sp (Rosaceae em Timbó-SC, Brasil

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Leônidas João de Mello Junior

2011-09-01

Full Text Available O presente trabalho verificou experimentalmente a ecologia da polinização da amoreira-preta (Rubus sp.. Objetivou-se confirmar a síndrome de polinização de Rubus sp., por meio de análise de seu sistema reprodutivo, quantificação da produção diária de néctar, levantamento da entomofauna que visita as flores da amoreira na área de estudo e análise do seu comportamento polinizador. Os experimentos foram realizados em uma área de cultivo de amoreira-preta, no mês de dezembro de 2005, município de Timbó (SC. Constatou-se que a maior taxa de frutificação (48,3 % ± 3,2 ocorreu via polinização livre, onde os insetos não foram excluídos. Foi verificada a ocorrência de autopolinização, porém com taxa inferior de frutificação (12,2% ± 4,9. A anemofilia não foi constatada na espécie. A avaliação da produção de néctar em Rubus sp. resultou em valores compatíveis com a síndrome de melitofilia. Os visitantes florais coletados e observados sobre as flores de Rubus sp. foram predominantemente abelhas da ordem Hymenoptera (97%, que iniciam, em menor número, a atividade de forrageamento às 8h, com pico de atividade às 12h e declinando até às 16h. As coletas resultaram numa amostragem de 1.360 abelhas, divididas em quatro famílias e 13 espécies. A família com maior riqueza de espécies (N = 7 foi Halictidae e a mais abundante foi Apidae, com 1.288 indivíduos. Em Apidae, houve o predomínio da espécie exótica Apis mellifera, cuja representação na amostra foi de 1.246 indivíduos. Os dados da abundância e as observações naturalísticas do seu comportamento da flor apontaram A. mellifera como o principal polinizador de Rubus sp., mas confirmam que as demais espécies de abelhas também participam na polinização de Rubus sp.

A Theory of Causal Learning in Children: Causal Maps and Bayes Nets

Science.gov (United States)

Gopnik, Alison; Glymour, Clark; Sobel, David M.; Schulz, Laura E.; Kushnir, Tamar; Danks, David

2004-01-01

The authors outline a cognitive and computational account of causal learning in children. They propose that children use specialized cognitive systems that allow them to recover an accurate "causal map" of the world: an abstract, coherent, learned representation of the causal relations among events. This kind of knowledge can be perspicuously…

Aspectos fitossociológicos de um fragmento da floresta natural de Astronium balansae engl., no município de Bossoroca, RS

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Boligon Alexandra Augusti

2005-01-01

Full Text Available Este estudo objetivou conhecer a composição florística e a estrutura fitossociológica de um fragmento da Floresta Natural de Astronium balansae Engl., no município de Bossoroca, RS, Brasil. Foram demarcadas 7 unidades amostrais de 10x100m (1000m2 onde observou-se a ocorrência de 476 indivíduos com Circunferência à Altura do Peito (CAP = 30cm, distribuídos em 35 espécies e 25 famílias. As espécies mais características e importantes da floresta foram Astronium balansae, Myrcianthes pungens, Patagonula americana, Eugenia uniflora e Parapiptadenia rigida. As famílias Myrtaceae, Meliaceae e Euphorbiaceae foram as mais representativas do fragmento florestal estudado. O valor do Índice de diversidade de Shannon foi 3.

Parâmetros fitossociológicos de um cerrado no Parque Nacional Da Serra Do Cipó, MG Phytosociological parameters of a cerrado in "Serra Do Cipó" national park, Minas Gerais, Brazil

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João Augusto Alves Meira Neto

2002-10-01

Full Text Available A riqueza de espécies e os fatores determinantes da ocorrência da vegetação de cerrado há muito têm despertado o interesse de pesquisadores. Muitos cerrados protegidos em unidades de conservação ainda não foram investigados florística e estruturalmente. Neste trabalho foi realizado um levantamento florístico e fitossociológico no Parque Nacional da Serra do Cipó (19º22'01''S e 43º37'10''W. Foram instaladas 12 parcelas de 150 m² e foram amostrados todos os indíviduos lenhosos com circunferência do caule à altura do solo maior ou igual a 10 cm. Foram relacionadas 44 espécies de 37 gêneros e 30 famílias. Entre estas, Leguminosae Caesalpinioideae, Leguminosae Mimosoideae e Guttiferae, com três espécies cada, foram as mais ricas. As espécies mais importantes (VI foram Hymenaea stigonocarpa, Allagoptera campestris, Diospyros hispida, Rapanea guianensis e Piptocarpha rotundifolia.The diversity of species and the factors determining the occurrence of cerrado vegetation have long called the attention of researchers. Many protected cerrados in Conservation Units have not been floristically and structurally studied. This work conducted a floristic and phytosociological survey of the Parque Nacional da "Serra do Cipó" ("Serra do Cipó" National Park (19º22'01''S and 43º37'10''W. Twelve quadrats of 150 m² were established and all individuals with a stem circumference at ground level larger than or equal to 10 cm were sampled. A total of 44 species of 37 genera and 30 families were found. The richest families were Leguminosae Caesalpinioideae, Leguminosae Mimosoideae and Guttiferae, with three species each. The most important species (VI were Hymenaea stigonocarpa, Allagoptera campestris, Diospyros hispida, Rapanea guianensis and Piptocarpha rotundifolia.

Composición florística de pequeñas aéreas de mallines con distintas exposición y pendiente

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Daniel Grima

2015-04-01

Full Text Available El trabajo muestra la composición florística de tres pequeñas áreas de mallines localizados en la meseta volcánica “Bella Vista” (51° 53´ S y 70° 32´ O. La misma posee una extensión aproximada de 45 km2 y presenta laderas con pendientes medias a fuertes que oscilan entre 5% y 9% (IGM 1997 y distinta exposición a la insolación y al viento. El objetivo del trabajo es caracterizar la diversidad de especies y y el estado de degradación según la aptitud forrajera (Suarez et al 2010 de los mallines en relación con la exposición y la pendiente. En gabinete se reconocieron los límites de los mallines y seleccionaron los sitios a muestrear en una imagen satelital de alta resolución espacial (IKONOS 2002. En campo se realizaron transectas perpendiculares a la pendiente y se identificaron las especies indicadoras de deterioro y de aptitud forrajera. Se estimó visualmente la cobertura vegetal y la distribución espacial de los factores de degradación.Los tres mallines exhiben composiciones florísticas y estados de degradación distintos. Carlota y Bella Vista presentan cobertura vegetal del 90 % y más diversidad florística por situarse en orientaciones menos expuestas al viento. La insolación directa favorece a Carlota en la mayor cantidad de especies relevadas (20 y 11 respectivamente, el estado de deterioro puede clasificarse de moderado a moderado severo. El mallin Gallegos Chico, con exposición oeste, recibe la acción directa del viento y su efecto abrasivo sobre las plantas afectando su porte y porcentaje de cobertura vegetal.

Neural Correlates of Causal Power Judgments

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Denise Dellarosa Cummins

2014-12-01

Full Text Available Causal inference is a fundamental component of cognition and perception. Probabilistic theories of causal judgment (most notably causal Bayes networks derive causal judgments using metrics that integrate contingency information. But human estimates typically diverge from these normative predictions. This is because human causal power judgments are typically strongly influenced by beliefs concerning underlying causal mechanisms, and because of the way knowledge is retrieved from human memory during the judgment process. Neuroimaging studies indicate that the brain distinguishes causal events from mere covariation, and between perceived and inferred causality. Areas involved in error prediction are also activated, implying automatic activation of possible exception cases during causal decision-making.

Agency, time and causality

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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.

Physiological potential of cauliflower seeds Potencial fisiológico de sementes de couve-flor

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Ana Lúcia Pereira Kikuti

2008-01-01

Full Text Available The assessment of seed physiological performance is essential to provide consistent information to compose quality control programs conducted by seed companies and allow prompt decisions to reduce post-harvest and commercialization problems. This research was carried to evaluate the efficiency of different procedures to determine cauliflower seed vigor. Six lots of the cultivar Sharon were initially characterized by germination and seedling emergence, and subsequently subjected to traditional and saturated salt accelerated aging, controlled deterioration, electrical conductivity, and potassium leachate tests, in two evaluation times. The traditional accelerated aging (41ºC/48 h, the saturated salt procedure (45ºC/72 h, the controlled deterioration (moisture content adjusted to 20% or 22% and aging at 45ºC/24 h, the electrical conductivity (50 seeds/75 mL water and evaluation after 4 h and the potassium leakage (25 seeds/50 mL of water and evaluation after 30 min laboratory tests are sensitive to detect differences in the physiological potential of cauliflower seeds. However, those results did not relate to the percentage seedling emergence in greenhouse controlled conditions, as a consequence of the favorable conditions for emergence. However, the differences identified in the tests may be related to the ability of seed lots to perform in less favorable environments.A eficiência da determinação do potencial fisiológico de lotes de sementes é essencial para a obtenção de informações consistentes, permitindo a composição de programas de controle de qualidade de sementes e a obtenção de informações consistentes para a redução de problemas pós-colheita e durante a comercialização. O objetivo desta pesquisa foi comparar a eficiência de diferentes procedimentos para a determinação do vigor de sementes de couve-flor. Para tanto, foram utilizados seis lotes do cultivar Sharon, caracterizados inicialmente pelos testes de germina

Causal boundary for strongly causal spacetimes: Pt. 1

International Nuclear Information System (INIS)

Szabados, L.B.

1989-01-01

In a previous paper an analysis of the general structure of the causal boundary constructions and a new explicit identification rule, built up from elementary TIP-TIF gluings, were presented. In the present paper we complete our identification by incorporating TIP-TIP and TIF-TIF gluings as well. An asymptotic causality condition is found which, for physically important cases, ensures the uniqueness of the endpoints of the non-spacelike curves in the completed spacetime. (author)

Structural Equations and Causal Explanations: Some Challenges for Causal SEM

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Markus, Keith A.

2010-01-01

One common application of structural equation modeling (SEM) involves expressing and empirically investigating causal explanations. Nonetheless, several aspects of causal explanation that have an impact on behavioral science methodology remain poorly understood. It remains unclear whether applications of SEM should attempt to provide complete…

Florística, estrutura e características do solo de um fragmento de floresta paludosa no sudeste do Brasil Floristics, structure and soil characteristics of a swamp forest fragment, in southeast Brazil

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Laércio Loures

2007-12-01

Full Text Available Realizou-se o levantamento da comunidade arbórea de uma floresta semidecidual montana ribeirinha, situada no alto Rio Pardo, Santa Rita de Caldas, Minas Gerais (altitude 1.156 a 1.203 m, com o objetivo de avaliar as variações estruturais e variáveis ambientais relacionadas ao substrato. Foram analisadas a densidade, área basal e distribuição de tamanho das árvores e a composição florística da comunidade. Foram alocadas 25 parcelas de 10x40 m para amostragem dos indivíduos arbóreos com diâmetro à altura do peito > 5 cm. Também foram coletados dados topográficos e amostras do solo para análises químicas e texturais. Foram registrados 2.982 indivíduos, 50 famílias, 78 gêneros e 110 espécies. Foram verificados três subgrupos de solos (Organossolos, Gleissolos Melânicos e Gleissolos Háplicos, distribuídos em seqüência, acompanhando o curso do riacho. A comunidade arbórea apresentou uma composição florística e estrutural diferente das florestas paludosas e aluviais do Sudeste e Sul do Brasil, em altitudes menores. Uma análise de correspondência canônica detectou um gradiente de distribuição das espécies arbóreas, principalmente correlacionadas com as variações de argila e de cota altimétrica.A survey of the tree community was conducted for an upland semideciduous riparian forest, located on the upper Rio Pardo, Santa Rita de Caldas, Minas Gerais (1156 to 1203 m altitude, in order to evaluate structural variation and environmental variables associated with the substrate. Density, basal area, tree size distribution and floristic composition were evaluated. In 25 10x40 m plots, all trees with dbh > 5 cm were sampled, topographical aspects were determined and soil samples were collected for chemical and textural analyses. A total of 2982 individuals from 50 families, 78 genera and 110 species were recorded. A sequence of three soil subgroups (Organosoil, Melanic Gleisoil and Haplic Gleisoil was registered in a

Causality discovery technology

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Chen, M.; Ertl, T.; Jirotka, M.; Trefethen, A.; Schmidt, A.; Coecke, B.; Bañares-Alcántara, R.

2012-11-01

Causality is the fabric of our dynamic world. We all make frequent attempts to reason causation relationships of everyday events (e.g., what was the cause of my headache, or what has upset Alice?). We attempt to manage causality all the time through planning and scheduling. The greatest scientific discoveries are usually about causality (e.g., Newton found the cause for an apple to fall, and Darwin discovered natural selection). Meanwhile, we continue to seek a comprehensive understanding about the causes of numerous complex phenomena, such as social divisions, economic crisis, global warming, home-grown terrorism, etc. Humans analyse and reason causality based on observation, experimentation and acquired a priori knowledge. Today's technologies enable us to make observations and carry out experiments in an unprecedented scale that has created data mountains everywhere. Whereas there are exciting opportunities to discover new causation relationships, there are also unparalleled challenges to benefit from such data mountains. In this article, we present a case for developing a new piece of ICT, called Causality Discovery Technology. We reason about the necessity, feasibility and potential impact of such a technology.

Reasoning with Causal Cycles

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Rehder, Bob

2017-01-01

This article assesses how people reason with categories whose features are related in causal cycles. Whereas models based on causal graphical models (CGMs) have enjoyed success modeling category-based judgments as well as a number of other cognitive phenomena, CGMs are only able to represent causal structures that are acyclic. A number of new…

Novas linhagens de repôlho e couve-flor para o Estado de São Paulo Improved cabbage and cauliflower types for São Paulo

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Leocádio de Souza Camargo

1956-01-01

Full Text Available A experimentação com repôlho (Brassica oleracea L. var. capitata L. e couve-flor (B. oleracea L. var. botrytis cauliflora, Gars, D.C. foi intensificada no Instituto Agronômico a partir de 1941 e, em 1944 iniciaram-se os trabalhos sôbre o seu melhoramento. No presente trabalho são feitas referências sobre florescimento, polinização, genética, problemas da produção de sementes, deficiência de boro, época de semeação para produção de cabeças e de sementes, pragas e moléstias. Experimentaram-se 74 variedades de repôlho e 59 de couve-flor. O maior grupo de variedades produz bem na época fresca do ano, quando as temperaturas médias mensais variam em tôrno de 22,5°C durante o crescimento, e de 16,5°C, na época de formação de cabeças. Para plantio na época quente do ano, com temperaturas médias mensais variando de 20,4 a 22,6°C, durante o crescimento, e de 18 a 22,2°C, na formação de cabeças, prestam-se a variedade de repôlho paulista "Louco" (I.A.C. n.° 758 melhorada no Instituto Agronômico, e a couve-flor "Early Benares", n.° 1383, procedente de Sutton's Seed, Índia, também adaptada às nossas condições climáticas. Em 1944 iniciou-se em Campinas, na E. E. Central, o melhoramento do repolho "Louco" com material procedente de Mogí das Cruzes, São Paulo. Seus defeitos foram eliminados, possuindo-se dêle boas linhagens. Dêsse repôlho foram produzidas, em campos de cooperação da Divisão de Fomento Agrícola, em 1950 e 1951, respectivamente 750 e 722,5 kg de sementes, obtendo-se em média, 26,5 g por planta ou 53 g por m2. Visando à produção de sementes, a melhor época de semeadura é dezembro. As cabeças formam-se em março e abril; após a retirada da cabeça as gemas do caule brotam; desses brotos, dois dos mais fortes devem ficar para a produção de sementes. O florescimento e a colheita das sementes dão-se em épocas favoráveis. As sementes são colhidas desde 160 dias após o corte da cabe

Structure and Strength in Causal Induction

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Griffiths, Thomas L.; Tenenbaum, Joshua B.

2005-01-01

We present a framework for the rational analysis of elemental causal induction--learning about the existence of a relationship between a single cause and effect--based upon causal graphical models. This framework makes precise the distinction between causal structure and causal strength: the difference between asking whether a causal relationship…

Regression to Causality : Regression-style presentation influences causal attribution

DEFF Research Database (Denmark)

Bordacconi, Mats Joe; Larsen, Martin Vinæs

2014-01-01

of equivalent results presented as either regression models or as a test of two sample means. Our experiment shows that the subjects who were presented with results as estimates from a regression model were more inclined to interpret these results causally. Our experiment implies that scholars using regression...... models – one of the primary vehicles for analyzing statistical results in political science – encourage causal interpretation. Specifically, we demonstrate that presenting observational results in a regression model, rather than as a simple comparison of means, makes causal interpretation of the results...... more likely. Our experiment drew on a sample of 235 university students from three different social science degree programs (political science, sociology and economics), all of whom had received substantial training in statistics. The subjects were asked to compare and evaluate the validity...

Composição florística de plantas daninhas em um lago do Rio Solimões, Amazonas Floristic composition of weeds in a lake of Solimoes River, Amazonas, Brazil

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S.M.F. Albertino

2009-03-01

Full Text Available As áreas inundáveis localizadas na bacia dos rios Amazonas e Solimões são denominadas várzeas. A inundação é um evento natural que promove mudanças na estrutura e composição florística dessas comunidades. O conhecimento da diversidade de espécies é de fundamental importância para o entendimento da dinâmica da regeneração natural de espécies nos ecossistemas amazônicos. Este trabalho teve como objetivo levantar a composição florística do solo do fundo do lago do Manaquiri-AM, em um período de seca excepcional, ocorrida em 2005, na Amazônia. Foram realizadas coletas de material botânico em duas áreas do lago, em novembro de 2005; para a amostragem, utilizou-se um quadrado de madeira de 0,36 m², atirado aleatoriamente por 20 vezes em cada local de estudo. A vegetação emergente foi de 5.958 indivíduos, distribuídos em sete famílias e nove espécies. As famílias mais representativas em número de espécies foram Poaceae e Cyperaceae. Cyperus esculentus e Luziola spruceana foram as mais frequentes, e Mimosa pudica e Alternanthera sessilis, as de maior abundância. C. esculentus e M. pudica apresentaram maior número de indivíduos, de densidade e de valor de importância. As espécies de plantas encontradas neste estudo mantiveram sua capacidade de crescer e se desenvolver mesmo após longo período submersas.The swamps located at the basins of the Amazonas and Solimões rivers are denominated "várzeas". In these areas, flooding is a natural event that changes the structure and composition of the local plants. Thus, knowing the species diversity in these Amazon region areas is extremely important to understand the dynamics of the natural regeneration of the Amazon ecosystem species. Accordingly, the goal of this study was to survey the soil floristic composition at the bottom of the Manaquiri Lake, Amazon, during an exceptional dry period in 2005. Plants were collected in two areas of the lake in November 2005. Flora

Efeitos da desertificação na composição de espécies do bioma Caatinga, Paraíba/Brasil

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Bartolomeu Israel Souza

2015-12-01

Full Text Available A desertificação é reconhecida como uma das principais ameaças a zonas de clima seco em todo mundo. No Brasil, esse fenômeno tem atingido especialmente o bioma Caatinga, para o qual ainda existe pouca informação acerca de suas consequências na composição florística. O presente trabalho objetivou avaliar este efeito em sítios inseridos em três municípios da Paraíba (Nordeste, Brasil. Sítios de amostragem foram previamente selecionados por imagens de satélite usando a técnica IVDN, seguido de um levantamento vegetacional in locu (método transecto abrangendo ambientes não-desertificados e desertificados. Análises univariadas (teste U e multivariadas (nMDS foram usadas a verificar diferenças nas variáveis vegetacionais e demonstrar padrões de dissimilaridades entre os ambientes contrastantes, respectivamente. A riqueza e diversidade de plantas diferiram significativamente entre os ambientes. O nMDS identificou três grupos de plantas: i espécies associadas a áreas não-desertificadas (Anadenanthera columbrina, Bauhinia cheilantha e Tabebuia impetiginosa, ii espécies relacionadas a áreas desertificadas (Aspidosperma pyrifolium, Jatropha molissima, Mimosa tenuiflora e Pilosocereus gounellei e iii espécies presentes nos dois tipos de ambientes (Croton sonderianus, Piptadenia stipulacea e Poincianella pyramidalis. Os resultados apontaram que a desertificação desencadeou mudanças severas na composição florística da Caatinga, indicando também que as intervenções humanas foram determinantes no estabelecimento dos diferentes ambientes.

Causality in Europeanization Research

DEFF Research Database (Denmark)

Lynggaard, Kennet

2012-01-01

to develop discursive institutional analytical frameworks and something that comes close to the formulation of hypothesis on the effects of European Union (EU) policies and institutions on domestic change. Even if these efforts so far do not necessarily amount to substantive theories or claims of causality......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......, 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 study...

Produção de rabanete sob o efeito residual da adubação verde no consórcio de beterraba e rúcula

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A. K. Oliveira

2015-12-01

Full Text Available Sistemas de cultivo com incorporação de adubos verdes podem preservar a capacidade produtiva do solo em longo prazo, oferecendo resíduos que proporcionarão melhorias nas condições físicas, química e biológica do solo tornando-o propício para a implantação de uma cultura sucedente. Diante disso, o trabalho teve como objetivo avaliar produção de rabanete sob o efeito residual da adubação verde no consórcio de beterraba e rúcula. O delineamento experimental usado foi em blocos casualizados com cinco repetições. Os tratamentos utilizados foram o efeito residual de quatro quantidades de flor-de-seda incorporadas ao solo (10, 25, 40 e 55 t ha-¹ em base seca. As características avaliadas na cultura do rabanete foram: altura e diâmetro de plantas, número de folhas, produtividade total e comercial de raízes, massa seca da parte aérea e de raízes. O efeito residual da incorporação de flor-de-seda ao solo na quantidade de 55 t ha-¹ proporcionou a maior produtividade de raízes comerciais de rabanete, e assim podemos afirmar que a adubação verde com flor-de-seda apresenta-se como uma prática promissora para o produtor de hortaliças em cultivo sucessivo.Radish production under the residual effect of green manure in the consortium beet and arugulaAbstract: Cropping systems in with incorporation of green manures can preserve the productive capacity of the soil over time providing waste to the soil improvement in the conditions physical, chemical and biological, making it suitable for the implementation of a succeeding crop. Therefore the aim of this study was to evaluate the radish production under the residual effect of green manure in the consortium beet and arugula. The experimental design was a randomized complete block design with five replications. The treatments were the residual effect of four amounts of fleur-de-silk incorporated into the soil (10, 25, 40 and 55 t ha-¹ dry basis. The characteristics evaluated in the

Caracterização florística da vegetação sobre afloramento rochoso na Estação Experimental de Itapeva, SP, e comparação com áreas de campos rupestres e de altitude. Floristic characterization on rocky outcrop in the Itapeva Experimental Station, SP, and comparison with areas of rocky grasslands and high-altitude grasslands.

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Silvana Cristina Pereira Muniz de SOUZA

2011-06-01

Full Text Available A classificação de comunidades vegetais nem sempre é tarefa fácil, principalmente quando se trata de tipos de vegetação pouco estudados. Esse é o caso davegetação sobre afloramento rochoso da Estação Experimental de Itapeva – EEI, situada no sudoeste do Estado de São Paulo, região que abriga remanescentes de Cerrado e Mata Atlântica. Visando caracterizar e classificar essa vegetação, foram realizadas coletas mensais de material botânico no período de agosto de 2008 a fevereiro de 2010. A lista de espécies obtida foi comparada com a de campos rupestres e de altitude brasileiros. As comparações foram realizadas por meio de análise de agrupamento, “TWINSPAN” e “NMS”. Foram encontradas 135 espécies, 48 famílias e 108 gêneros. As famílias mais representativas foram Fabaceae, Asteraceae, Bignoniaceae, Myrtaceae, Melastomataceae, Poaceae, Apocynaceae, Sapindaceae e Orchidaceae. A análise de agrupamento com os dados de distribuição de riqueza entre famílias sugeriu maior afinidade florística entre o afloramento rochoso estudado e os campos rupestres. Para os dados de composição de espécies, os diferentes métodos de ligação agruparam a área de estudo ora com campos de altitude ora com campos rupestres. A “NMS” evidenciou o caráter contínuo da variação florística, mas reiterou a maior similaridade entre a área de estudo e os campos rupestres. A “TWINSPAN” reforçou essa hipótese e apontou a família Fabaceae e as espécies Miconia albicans (Sw. Steud. e Periandra mediterranea (Vell. Taub como indicadoras de campos rupestres. O tipo de solo, formado a partir de rochas areníticas, constitui o fator determinante mais plausível para as relações florísticas encontradas.The classification of vegetation communities is not an easy task, especially regarding less studied vegetation types. This is the case for rocky outcrop vegetation in the Itapeva Experimental Station – EEI, located in the

Causality and headache triggers

Science.gov (United States)

Turner, Dana P.; Smitherman, Todd A.; Martin, Vincent T.; Penzien, Donald B.; Houle, Timothy T.

2013-01-01

Objective The objective of this study was to explore the conditions necessary to assign causal status to headache triggers. Background The term “headache trigger” is commonly used to label any stimulus that is assumed to cause headaches. However, the assumptions required for determining if a given stimulus in fact has a causal-type relationship in eliciting headaches have not been explicated. Methods A synthesis and application of Rubin’s Causal Model is applied to the context of headache causes. From this application the conditions necessary to infer that one event (trigger) causes another (headache) are outlined using basic assumptions and examples from relevant literature. Results Although many conditions must be satisfied for a causal attribution, three basic assumptions are identified for determining causality in headache triggers: 1) constancy of the sufferer; 2) constancy of the trigger effect; and 3) constancy of the trigger presentation. A valid evaluation of a potential trigger’s effect can only be undertaken once these three basic assumptions are satisfied during formal or informal studies of headache triggers. Conclusions Evaluating these assumptions is extremely difficult or infeasible in clinical practice, and satisfying them during natural experimentation is unlikely. Researchers, practitioners, and headache sufferers are encouraged to avoid natural experimentation to determine the causal effects of headache triggers. Instead, formal experimental designs or retrospective diary studies using advanced statistical modeling techniques provide the best approaches to satisfy the required assumptions and inform causal statements about headache triggers. PMID:23534872

Viscous causal cosmologies

International Nuclear Information System (INIS)

Novello, M.; Salim, J.M.; Torres, J.; Oliveira, H.P. de

1989-01-01

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) [pt

Dynamics of Quantum Causal Structures

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Castro-Ruiz, Esteban; Giacomini, Flaminia; Brukner, Časlav

2018-01-01

It was recently suggested that causal structures are both dynamical, because of general relativity, and indefinite, because of quantum theory. The process matrix formalism furnishes a framework for quantum mechanics on indefinite causal structures, where the order between operations of local laboratories is not definite (e.g., one cannot say whether operation in laboratory A occurs before or after operation in laboratory B ). Here, we develop a framework for "dynamics of causal structures," i.e., for transformations of process matrices into process matrices. We show that, under continuous and reversible transformations, the causal order between operations is always preserved. However, the causal order between a subset of operations can be changed under continuous yet nonreversible transformations. An explicit example is that of the quantum switch, where a party in the past affects the causal order of operations of future parties, leading to a transition from a channel from A to B , via superposition of causal orders, to a channel from B to A . We generalize our framework to construct a hierarchy of quantum maps based on transformations of process matrices and transformations thereof.

Dinâmica inicial da composição florística de uma área restaurada na região do Pontal do Paranapanema, São Paulo, Brasil Initial dynamics of floristic composition in a restoresd area in the region of Pontal do Paranapanema, São Paulo state, Brazil

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Elisangela Ronconi Rodrigues

2010-10-01

Full Text Available O Pontal do Paranapanema, extremo oeste do Estado de São Paulo, é marcado pela recente devastação florestal, e ações visando à recuperação de áreas onde outrora havia cobertura florestal tornam-se indispensáveis para a conservação da biodiversidade na região, principalmente quando se trata de áreas de Reserva Legal ou Preservação Permanente. Diante do exposto, esta pesquisa teve como objetivo analisar a dinâmica inicial da composição florística em uma área de Reserva Legal restaurada. O trabalho foi realizado no assentamento Nova Esperança, Município de Euclides da Cunha Paulista, em uma área de 26,75 ha. O levantamento das espécies foi realizado pelo método de parcelas (16 parcelas de 20 x 30 m em duas fases distintas do plantio, e as análises foram feitas utilizando-se o software Fitopac. Os resultados evidenciaram diminuição da biodiversidade pela alta mortalidade de espécies, levando à conclusão de que em projetos de restauração as intervenções são necessárias para a manutenção do plantio mesmo em sua fase inicial.The Pontal do Paranapanema Region is located in the western range of the State of São Paulo is characterized by recent forest destruction and actions are needed for forest restorations and conservation of biodiversity in the region, principally when if treated of areas of Legal Reserve or Permanent Preservation. Before of the exposed this research had it objective analyze the dynamics initial from floristic composition an area of Legal Reserve restored. This work was realized into the Nova Esperança settlement, city of Euclides da Cunha Paulista, an area of 26,75 ha. The lifting from the species was realized at method of parcels (16 parcels of 20 x 30 m into two phases differentiate of the plantation, and the analisys have been using Fitopac software.The results they show only one decrease from biodiversity by high mortality of species, taking the conclusive what projects of restoration

Causal inference based on counterfactuals

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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.

The argumentative impact of causal relations

DEFF Research Database (Denmark)

Nielsen, Anne Ellerup

1996-01-01

such as 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.......The semantic relations between and within utterances are marked by the use of connectors and adverbials. One type of semantic relations is causal relations expressed by causal markers such as because, therefore, so, for, etc. Some of these markers cover different types of causal relations...

Entropy for theories with indefinite causal structure

International Nuclear Information System (INIS)

Markes, Sonia; Hardy, Lucien

2011-01-01

Any theory with definite causal structure has a defined past and future, be it defined by light cones or an absolute time scale. Entropy is a concept that has traditionally been reliant on a definite notion of causality. However, without a definite notion of causality, the concept of entropy is not all lost. Indefinite causal structure results from combining probabilistic predictions and dynamical space-time. The causaloid framework lays the mathematical groundwork to be able to treat indefinite causal structure. In this paper, we build on the causaloid mathematics and define a causally-unbiased entropy for an indefinite causal structure. In defining a causally-unbiased entropy, there comes about an emergent idea of causality in the form of a measure of causal connectedness, termed the Q factor.

Florística e fitossociologia de espécies arbóreas e arbustivas em uma área de Caatinga em Arcoverde, PE, Brasil

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Mozart Duarte Barbosa

2012-10-01

Full Text Available Os estudos de florística e fitossociologia contribuem significativamente para o conhecimento das formações florestais, visto que evidenciam a riqueza e heterogeneidade dos ambientes avaliados. O trabalho foi realizado em um fragmento de Caatinga hipoxerófila no Município de Arcoverde, PE, e teve como objetivo verificar a composição florística e parâmetros fitossociológicos das espécies arbóreas e arbustivas que compõem o fragmento. O estudo foi realizado em 40 parcelas de 10 x 25 m, sendo o nível de inclusão a circunferência a 1,3 m do solo com CAP > 10 cm. Foram estimados a densidade absoluta e relativa, a frequência absoluta e relativa, a dominância absoluta e relativa e o valor de importância; a diversidade específica foi dada pelo índice de diversidade de Shannon - Weaver (H' e equabilidade de Pielou, sendo determinada a distribuição hipsométrica em intervalos de 1 m e distribuição diamétrica em intervalos com amplitude de 3 cm. No levantamento florístico das adultas, foram encontrados 1.491 indivíduos vivos, distribuídos em 36 espécies arbóreo-arbustivas, 19 famílias e 31 gêneros. As famílias que mais se destacaram foram Mimosaceae, Euphorbiaceae, Anacardiaceae, Caesalpiniaceae e Rhamnaceae. O índice de diversidade de Shannon-Weaver foi de 2,05 nats/ind. e a equabilidade de Pielou, de 0,57. Nos sete parâmetros fitossociólogicos avaliados, as espécies que mais se destacaram foram Mimosa ophthalmocentra, Poincianella pyramidalis, Senegalia bahiensis, Senegalia paniculata, Croton blanchetianus e Mimosa tenuiflora, indicando ser essas espécies as mais bem adaptadas ao ambiente avaliado, tanto nas condições edafoclimáticas quanto na competição com as demais espécies presentes no fragmento de Caatinga em Arcoverde, PE.

Dynamics of Quantum Causal Structures

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Esteban Castro-Ruiz

2018-03-01

Full Text Available It was recently suggested that causal structures are both dynamical, because of general relativity, and indefinite, because of quantum theory. The process matrix formalism furnishes a framework for quantum mechanics on indefinite causal structures, where the order between operations of local laboratories is not definite (e.g., one cannot say whether operation in laboratory A occurs before or after operation in laboratory B. Here, we develop a framework for “dynamics of causal structures,” i.e., for transformations of process matrices into process matrices. We show that, under continuous and reversible transformations, the causal order between operations is always preserved. However, the causal order between a subset of operations can be changed under continuous yet nonreversible transformations. An explicit example is that of the quantum switch, where a party in the past affects the causal order of operations of future parties, leading to a transition from a channel from A to B, via superposition of causal orders, to a channel from B to A. We generalize our framework to construct a hierarchy of quantum maps based on transformations of process matrices and transformations thereof.

Estudios florísticos y ecológicos sobre las algas de agua dulce de turberas de Tierra del Fuego

OpenAIRE

Mataloni, María Gabriela

1994-01-01

En esta Tesis Doctoral se realizan diversas investigaciones florísticas y ecológicas sobre las algas de turberas de Sphagnum de la provincia de Tierra Fuego. Para ello se condijeron básicamente dos trabajos. en la primera parte se estudiaron ocho ojos de agua pertenecientes a siete turberas ubicadas en el sur de Tierra del Fuego. En cada una de ellas se muestrearon tanto el fitoplancton del agua libre como las algas que viven asociadas a Sphagnum a lo largo de un gradiente ambiental caracteri...

Causal inference in public health.

Science.gov (United States)

Glass, Thomas A; Goodman, Steven N; Hernán, Miguel A; Samet, Jonathan M

2013-01-01

Causal inference has a central role in public health; the determination that an association is causal indicates the possibility for intervention. We review and comment on the long-used guidelines for interpreting evidence as supporting a causal association and contrast them with the potential outcomes framework that encourages thinking in terms of causes that are interventions. We argue that in public health this framework is more suitable, providing an estimate of an action's consequences rather than the less precise notion of a risk factor's causal effect. A variety of modern statistical methods adopt this approach. When an intervention cannot be specified, causal relations can still exist, but how to intervene to change the outcome will be unclear. In application, the often-complex structure of causal processes needs to be acknowledged and appropriate data collected to study them. These newer approaches need to be brought to bear on the increasingly complex public health challenges of our globalized world.

Putting a cap on causality violations in causal dynamical triangulations

International Nuclear Information System (INIS)

Ambjoern, Jan; Loll, Renate; Westra, Willem; Zohren, Stefan

2007-01-01

The formalism of causal dynamical triangulations (CDT) provides us with a non-perturbatively defined model of quantum gravity, where the sum over histories includes only causal space-time histories. Path integrals of CDT and their continuum limits have been studied in two, three and four dimensions. Here we investigate a generalization of the two-dimensional CDT model, where the causality constraint is partially lifted by introducing branching points with a weight g s , and demonstrate that the system can be solved analytically in the genus-zero sector. The solution is analytic in a neighborhood around weight g s = 0 and cannot be analytically continued to g s = ∞, where the branching is entirely geometric and where one would formally recover standard Euclidean two-dimensional quantum gravity defined via dynamical triangulations or Liouville theory

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

A frequency domain subspace algorithm for mixed causal, anti-causal LTI systems

NARCIS (Netherlands)

Fraanje, Rufus; Verhaegen, Michel; Verdult, Vincent; Pintelon, Rik

2003-01-01

The paper extends the subspacc identification method to estimate state-space models from frequency response function (FRF) samples, proposed by McKelvey et al. (1996) for mixed causal/anti-causal systems, and shows that other frequency domain subspace algorithms can be extended similarly. The method

The Functions of Danish Causal Conjunctions

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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.

Space and time in perceptual causality

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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.

Causal inference in nonlinear systems: Granger causality versus time-delayed mutual information

Science.gov (United States)

Li, Songting; Xiao, Yanyang; Zhou, Douglas; Cai, David

2018-05-01

The Granger causality (GC) analysis has been extensively applied to infer causal interactions in dynamical systems arising from economy and finance, physics, bioinformatics, neuroscience, social science, and many other fields. In the presence of potential nonlinearity in these systems, the validity of the GC analysis in general is questionable. To illustrate this, here we first construct minimal nonlinear systems and show that the GC analysis fails to infer causal relations in these systems—it gives rise to all types of incorrect causal directions. In contrast, we show that the time-delayed mutual information (TDMI) analysis is able to successfully identify the direction of interactions underlying these nonlinear systems. We then apply both methods to neuroscience data collected from experiments and demonstrate that the TDMI analysis but not the GC analysis can identify the direction of interactions among neuronal signals. Our work exemplifies inference hazards in the GC analysis in nonlinear systems and suggests that the TDMI analysis can be an appropriate tool in such a case.

Paradoxical Behavior of Granger Causality

Science.gov (United States)

Witt, Annette; Battaglia, Demian; Gail, Alexander

2013-03-01

Granger causality is a standard tool for the description of directed interaction of network components and is popular in many scientific fields including econometrics, neuroscience and climate science. For time series that can be modeled as bivariate auto-regressive processes we analytically derive an expression for spectrally decomposed Granger Causality (SDGC) and show that this quantity depends only on two out of four groups of model parameters. Then we present examples of such processes whose SDGC expose paradoxical behavior in the sense that causality is high for frequency ranges with low spectral power. For avoiding misinterpretations of Granger causality analysis we propose to complement it by partial spectral analysis. Our findings are illustrated by an example from brain electrophysiology. Finally, we draw implications for the conventional definition of Granger causality. Bernstein Center for Computational Neuroscience Goettingen

On causality of extreme events

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Massimiliano Zanin

2016-06-01

Full Text Available 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 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. We further show how the proposed metric is able to outperform classical causality metrics, provided non-linear relationships are present and large enough data sets are available.

Causal symmetric spaces

CERN Document Server

Olafsson, Gestur; Helgason, Sigurdur

1996-01-01

This book is intended to introduce researchers and graduate students to the concepts of causal symmetric spaces. To date, results of recent studies considered standard by specialists have not been widely published. This book seeks to bring this information to students and researchers in geometry and analysis on causal symmetric spaces.Includes the newest results in harmonic analysis including Spherical functions on ordered symmetric space and the holmorphic discrete series and Hardy spaces on compactly casual symmetric spacesDeals with the infinitesimal situation, coverings of symmetric spaces, classification of causal symmetric pairs and invariant cone fieldsPresents basic geometric properties of semi-simple symmetric spacesIncludes appendices on Lie algebras and Lie groups, Bounded symmetric domains (Cayley transforms), Antiholomorphic Involutions on Bounded Domains and Para-Hermitian Symmetric Spaces

Predicting Causal Relationships from Biological Data: Applying Automated Causal Discovery on Mass Cytometry Data of Human Immune Cells

KAUST Repository

Triantafillou, Sofia; Lagani, Vincenzo; Heinze-Deml, Christina; Schmidt, Angelika; Tegner, Jesper; Tsamardinos, Ioannis

2017-01-01

Learning the causal relationships that define a molecular system allows us to predict how the system will respond to different interventions. Distinguishing causality from mere association typically requires randomized experiments. Methods for automated  causal discovery from limited experiments exist, but have so far rarely been tested in systems biology applications. In this work, we apply state-of-the art causal discovery methods on a large collection of public mass cytometry data sets, measuring intra-cellular signaling proteins of the human immune system and their response to several perturbations. We show how different experimental conditions can be used to facilitate causal discovery, and apply two fundamental methods that produce context-specific causal predictions. Causal predictions were reproducible across independent data sets from two different studies, but often disagree with the KEGG pathway databases. Within this context, we discuss the caveats we need to overcome for automated causal discovery to become a part of the routine data analysis in systems biology.

Predicting Causal Relationships from Biological Data: Applying Automated Causal Discovery on Mass Cytometry Data of Human Immune Cells

KAUST Repository

Triantafillou, Sofia

2017-09-29

Learning the causal relationships that define a molecular system allows us to predict how the system will respond to different interventions. Distinguishing causality from mere association typically requires randomized experiments. Methods for automated  causal discovery from limited experiments exist, but have so far rarely been tested in systems biology applications. In this work, we apply state-of-the art causal discovery methods on a large collection of public mass cytometry data sets, measuring intra-cellular signaling proteins of the human immune system and their response to several perturbations. We show how different experimental conditions can be used to facilitate causal discovery, and apply two fundamental methods that produce context-specific causal predictions. Causal predictions were reproducible across independent data sets from two different studies, but often disagree with the KEGG pathway databases. Within this context, we discuss the caveats we need to overcome for automated causal discovery to become a part of the routine data analysis in systems biology.

Investigating the multi-causal and complex nature of the accident causal influence of construction project features.

Science.gov (United States)

Manu, Patrick A; Ankrah, Nii A; Proverbs, David G; Suresh, Subashini

2012-09-01

Construction project features (CPFs) are organisational, physical and operational attributes that characterise construction projects. Although previous studies have examined the accident causal influence of CPFs, the multi-causal attribute of this causal phenomenon still remain elusive and thus requires further investigation. Aiming to shed light on this facet of the accident causal phenomenon of CPFs, this study examines relevant literature and crystallises the attained insight of the multi-causal attribute by a graphical model which is subsequently operationalised by a derived mathematical risk expression that offers a systematic approach for evaluating the potential of CPFs to cause harm and consequently their health and safety (H&S) risk implications. The graphical model and the risk expression put forth by the study thus advance current understanding of the accident causal phenomenon of CPFs and they present an opportunity for project participants to manage the H&S risk associated with CPFs from the early stages of project procurement. Copyright © 2011 Elsevier Ltd. All rights reserved.

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.

Causal Set Generator and Action Computer

OpenAIRE

Cunningham, William; Krioukov, Dmitri

2017-01-01

The causal set approach to quantum gravity has gained traction over the past three decades, but numerical experiments involving causal sets have been limited to relatively small scales. The software suite presented here provides a new framework for the generation and study of causal sets. Its efficiency surpasses previous implementations by several orders of magnitude. We highlight several important features of the code, including the compact data structures, the $O(N^2)$ causal set generatio...

Caracterização florística de uma área de contato entre Cerrado e Mata Atlântica na região sudoeste do Estado de São Paulo.

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Nicole da Silva PINTO

2012-06-01

Full Text Available Remanescentes de vegetação nativa em áreas de contato florístico e fitogeográfico têm especial importância na conservação da biodiversidade. A EstaçãoExperimental de Itapeva – EExI apresenta os referidos atributos, pois, abriga remanescentes de Floresta Estacional Semidecidual e de Cerrado. A EExI está localizada na BaciaHidrográfica do Alto Paranapanema – BHAP, na região sudoeste do Estado de São Paulo, considerada altamente degradada e prioritária para estudos de flora e fauna. Os objetivos deste trabalho foram: inventariar e caracterizar a vegetação e a flora vascular da EExI; ampliar o conhecimento sobre a biodiversidade da BHAP e subsidiar propostas de manejo. Realizou-se a caracterização fisionômica e florística considerando todos os hábitos, com coletas mensais de material botânico, de maio de 2009 a dezembro de 2010. Nas duas formações presentes na EExI, Mata Atlântica (Floresta Estacional Semidecidual – FES e Cerrado (campo rupestre, campo sujo úmido, campo sujo, cerrado ralo e cerrado denso, foram registradas 605 espécies. As famílias mais ricasna FES foram: Fabaceae, Myrtaceae, Rubiaceae, Asteraceae e Lauraceae, e no Cerrado:Asteraceae, Fabaceae, Myrtaceae, Melastomataceae e Bignoniaceae. Na FES predominaramas espécies arbóreas com 54,1% do total, ao contrário do Cerrado, onde predominaram as espécies não arbóreas (67,5%. Entre as espécies levantadas, 14 estão ameaçadas de extinção, mas apenas Araucaria angustifolia é citada nas listas estadual, nacional e mundial. Considerando o mosaico de FES e fisionomias de Cerrado, a alta diversidade de espécies e a presença de espécies ameaçadas de extinção, os remanescentes de vegetação da EExI são de extrema importância para a conservação e o estudo da biodiversidade regional.Remnants of native vegetation in areas of floristic and phytogeographical contact have special importance in biodiversity conservation. The Itapeva Experimental

Spectral dimension in causal set quantum gravity

International Nuclear Information System (INIS)

Eichhorn, Astrid; Mizera, Sebastian

2014-01-01

We evaluate the spectral dimension in causal set quantum gravity by simulating random walks on causal sets. In contrast to other approaches to quantum gravity, we find an increasing spectral dimension at small scales. This observation can be connected to the nonlocality of causal set theory that is deeply rooted in its fundamentally Lorentzian nature. Based on its large-scale behaviour, we conjecture that the spectral dimension can serve as a tool to distinguish causal sets that approximate manifolds from those that do not. As a new tool to probe quantum spacetime in different quantum gravity approaches, we introduce a novel dimensional estimator, the causal spectral dimension, based on the meeting probability of two random walkers, which respect the causal structure of the quantum spacetime. We discuss a causal-set example, where the spectral dimension and the causal spectral dimension differ, due to the existence of a preferred foliation. (paper)

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

International Nuclear Information System (INIS)

Kandemir Kocaaslan, Ozge

2013-01-01

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

¿CONFIEREN PODERES CAUSALES LOS UNIVERSALES TRASCENDENTES?

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José Tomás Alvarado Marambio

2013-11-01

Full Text Available This work discusses the so-called ‘Eleatic’ argument against the existence of transcendent universals, i. e. universals which does not require instantiation for its existence. The Eleatic Principle states that everything produces a difference in the causal powers of something. As transcendent universals seem not to produce such a difference, transcendent universals seem not to exist. The argument depends crucially on the justification and the interpretation of the Eleatic Principle. It is argued, first, that it is not very clear that the principle is justified, and, second, that there are several alternatives for its interpretation, in relation with the different theories one can endorse about modality or causality. Anti-realist theories of modality or causality are not very appropriate for the understanding of what should be a ‘causal power’. Neither does a realist theory of causality conjoined with a combinatorial theory of possible worlds. A ‘causal power’ seems to be better understood in connection with a realist –non-reductionist– theory of causality and a causal theory of modality. Taken in this way the Eleatic Principle, nonetheless, it is argued that transcendent universals do ‘produce’ a difference in causal powers, for every causal connection requires such universals for its existence.

Re-thinking local causality

NARCIS (Netherlands)

Friederich, Simon

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

mediation: R package for causal mediation analysis

OpenAIRE

Tingley, Dustin; Yamamoto, Teppei; Hirose, Kentaro; Keele, Luke; Imai, Kosuke

2012-01-01

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 su...

Levantamento da intensidade da alternariose e da podridão negra em cultivos orgânicos de brássicas em Pernambuco e Santa Catarina Survey of the intensity of Alternaria black spot and black rot on brassica species under organic farming systems in Pernambuco and Santa Catarina states, Brazil

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Luiz A M Peruch

2006-12-01

Full Text Available O objetivo deste trabalho foi avaliar a intensidade da alternariose, causada por Alternaria brassicicola e/ou Alternaria brassicae, e da podridão negra, causada por Xanthomonas campestris pv. campestris, em cultivos orgânicos de brássicas em Pernambuco e Santa Catarina. Os levantamentos foram realizados no período de novembro de 2001 a fevereiro de 2002, num total de 103 cultivos orgânicos de várias espécies de brássicas. Foram registradas elevadas prevalências das doenças nos estados, com exceção em couve-chinesa em Santa Catarina. A prevalência da alternariose foi 100% nos cultivos de brócolis em Pernambuco, bem como em couve-flor nos dois estados, enquanto a podridão negra atingiu esse nível nos cultivos de brócolis e couve-flor em Santa Catarina. Na média das diferentes espécies de brássicas, as doenças foram mais prevalentes em Pernambuco que Santa Catarina. Entretanto, as médias de severidade de cada doença no conjunto das brássicas não foram diferentes entre os estados, embora as condições climáticas tenham sido nitidamente distintas. A severidade da alternariose variou entre as espécies de brássicas somente em Pernambuco, com a menor severidade registrada em couve-manteiga. Em relação à podridão negra, apenas em Santa Catarina houve diferença na severidade entre as brássicas, sendo registrados os menores níveis em couve-chinesa. Não foram constatadas correlações significativas entre os níveis de severidade da alternariose e da podridão negra, bem como da severidade destas com o número total de plantas e a idade das plantas nos cultivos.The objective of this research was to evaluate the intensity of Alternaria black spot, caused by Alternaria brassicicola and/or Alternaria brassicae, and black rot, caused by Xanthomonas campestris pv. campestris in organic cultivation of brassicas in Pernambuco and Santa Catarina. The survey was carried aut from November 2001 to February 2002, in 103 fields under

Causal knowledge and the development of inductive reasoning.

Science.gov (United States)

Bright, Aimée K; Feeney, Aidan

2014-06-01

We explored the development of sensitivity to causal relations in children's inductive reasoning. Children (5-, 8-, and 12-year-olds) and adults were given trials in which they decided whether a property known to be possessed by members of one category was also possessed by members of (a) a taxonomically related category or (b) a causally related category. The direction of the causal link was either predictive (prey→predator) or diagnostic (predator→prey), and the property that participants reasoned about established either a taxonomic or causal context. There was a causal asymmetry effect across all age groups, with more causal choices when the causal link was predictive than when it was diagnostic. Furthermore, context-sensitive causal reasoning showed a curvilinear development, with causal choices being most frequent for 8-year-olds regardless of context. Causal inductions decreased thereafter because 12-year-olds and adults made more taxonomic choices when reasoning in the taxonomic context. These findings suggest that simple causal relations may often be the default knowledge structure in young children's inductive reasoning, that sensitivity to causal direction is present early on, and that children over-generalize their causal knowledge when reasoning. Copyright © 2013 Elsevier Inc. All rights reserved.

Causal Diagrams for Empirical Research

OpenAIRE

Pearl, Judea

1994-01-01

The primary aim of this paper is to show how graphical models can be used as a mathematical language for integrating statistical and subject-matter information. In particular, the paper develops a principled, nonparametric framework for causal inference, in which diagrams are queried to determine if the assumptions available are sufficient for identifiying causal effects from non-experimental data. If so the diagrams can be queried to produce mathematical expressions for causal effects in ter...

Capacidade reprodutiva e preferência da traça-das-crucíferas para diferentes brassicáceas Reproductive capacity and preference of the diamondback moth feeding on different brassicacea

Directory of Open Access Journals (Sweden)

Sergio A De Bortoli

2011-06-01

Full Text Available O objetivo desta pesquisa foi comparar diferentes cultivares de brassicáceas em relação à capacidade reprodutiva e preferência para alimentação e oviposição da traça-das-crucíferas. Os experimentos foram realizados utilizando-se as cultivares de repolho Midori, Chato-de-Quintal, híbridos da Top Seed® - Agristar (TPC 308, TPC 681 e TPC 668, couve-flor Bola de Neve, couve brócolis Ramoso Piracicaba Precoce e couve Manteiga da Geórgia, sendo esta última utilizada como padrão de suscetibilidade. Por meio dos dados biológicos de P. xylostella foram estimados os parâmetros necessários para a construção de tabela de vida de fertilidade, para comparação das cultivares testadas em relação à capacidade reprodutiva da praga. Em gaiolas de criação da traça-das-crucíferas foram colocados quatro quartos de folha, dois a dois, que justapostos formavam um círculo de 8 cm de diâmetro, confrontando-se os materiais dois a dois. As partes foram dispostas equidistantemente, para realização do teste de dupla chance de escolha (preferência para alimentação e oviposição e de múltipla chance de escolha, confrontando todos os substratos (preferência para alimentação. As cultivares que proporcionaram melhor desenvolvimento e reprodução para a traça-das-crucíferas foram couve Manteiga da Geórgia e couve brócolis. Para preferência alimentar constatou-se alta suscetibilidade em couve Manteiga e TPC 681 e para preferência de oviposição alta preferência para couve-flor Bola de Neve. Com isso, sugere-se a divisão das cultivares estudadas em quatro classes distintas: repolho Midori como moderadamente resistente (MR; couve-flor Bola de Neve e repolho Chato-de-Quintal como suscetíveis (S; couve brócolis, TPC308, TPC681 e TPC668 como moderadamente suscetíveis (MS; e couve Manteiga como altamente suscetível (AS.We compared different cultivars of crucifer in relation to reproductive capacity and preference for feeding and

The selective power of causality on memory errors.

Science.gov (United States)

Marsh, Jessecae K; Kulkofsky, Sarah

2015-01-01

We tested the influence of causal links on the production of memory errors in a misinformation paradigm. Participants studied a set of statements about a person, which were presented as either individual statements or pairs of causally linked statements. Participants were then provided with causally plausible and causally implausible misinformation. We hypothesised that studying information connected with causal links would promote representing information in a more abstract manner. As such, we predicted that causal information would not provide an overall protection against memory errors, but rather would preferentially help in the rejection of misinformation that was causally implausible, given the learned causal links. In two experiments, we measured whether the causal linkage of information would be generally protective against all memory errors or only selectively protective against certain types of memory errors. Causal links helped participants reject implausible memory lures, but did not protect against plausible lures. Our results suggest that causal information may promote an abstract storage of information that helps prevent only specific types of memory errors.

Influência da época de poda e tipos de polinização no florescimento e frutificação da pinha

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Paulo Cesar dos Santos

2014-01-01

Full Text Available O desconhecimento de tecnologias, que permitam melhorias no manejo da cultura da pinha, principalmente no que se refere às épocas de podas e métodos de polinização, limita o crescimento da área plantada desta fruta no Brasil. Nesse sentido, o objetivo deste trabalho foi avaliar o desenvolvimento de frutos de pinha em função de épocas de poda e de métodos de polinização. O experimento foi conduzido no município de São Francisco do Itabapoana-RJ, no período compreendido entre abril de 2001 e fevereiro de 2002. O delineamento experimental adotado foi em blocos casualizados (DBC, com parcelas subdivididas, em esquema fatorial 5x3, sendo cinco épocas de poda (maio, junho, julho, agosto e setembro de 2001 e três métodos de polinização (Polinização aberta ou natural; Polinização com pincel macio, realizada diretamente na flor, e Polinização realizada com bomba polinizadora, com quatro repetições. O comprimento e o diâmetro dos ramos foram influenciados pela época de poda. Os dois métodos de polinização artificial aumentaram a porcentagem de fecundação de frutos. O florescimento foi influenciado pela época de poda. Em média, o pico de desenvolvimento dos frutos foi verificado com aproximadamente 50 dias após a polinização e foi superior quando se utilizou a polinização artificial.

Rate-Agnostic (Causal) Structure Learning.

Science.gov (United States)

Plis, Sergey; Danks, David; Freeman, Cynthia; Calhoun, Vince

2015-12-01

Causal structure learning from time series data is a major scientific challenge. Extant algorithms assume that measurements occur sufficiently quickly; more precisely, they assume approximately equal system and measurement timescales. In many domains, however, measurements occur at a significantly slower rate than the underlying system changes, but the size of the timescale mismatch is often unknown. This paper develops three causal structure learning algorithms, each of which discovers all dynamic causal graphs that explain the observed measurement data, perhaps given undersampling. That is, these algorithms all learn causal structure in a "rate-agnostic" manner: they do not assume any particular relation between the measurement and system timescales. We apply these algorithms to data from simulations to gain insight into the challenge of undersampling.

Quando morre a flor do sertão: figuração da morte em “Buriti” de João Guimarães Rosa

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Sarah Maria Forte Diogo

2008-12-01

Full Text Available Este artigo tem por objetivo estudar de que modo é figurada a morte da personagem Maria Behú, de “Buriti”, Noites do sertão (1956, de João Guimarães Rosa e os símbolos que a ela se agregam. Para tanto, investigamos as focalizações narrativas que incidem sobre Behú, construindo sua imagem como beata, assexuada, atuante na esfera da metafísica, sendo a sua morte o início da intensa vivência da sexualidade pelos demais personagens. “Buriti” narra a estória dos habitantes da fazenda Buriti Bom e daqueles que por lá transitam e as mudanças que ocasionam na vida uns dos outros. Behú é a personagem que mais contrasta com o ambiente, pois dele difere por não apresentar marcas de erotismo ou vida plena. Behú funciona na novela como guardiã da tradição e da cultura, seus usos e seus costumes, estilizados pela linguagem roseana.Palavras-chave: João Guimarães Rosa; Cultura; Linguagem; Morte; Tradição.

Causality and analyticity in optics

International Nuclear Information System (INIS)

Nussenzveig, H.M.

In order to provide an overall picture of the broad range of optical phenomena that are directly linked with the concepts of causality and analyticity, the following topics are briefly reviewed, emphasizing recent developments: 1) Derivation of dispersion relations for the optical constants of general linear media from causality. Application to the theory of natural optical activity. 2) Derivation of sum rules for the optical constants from causality and from the short-time response function (asymptotic high-frequency behavior). Average spectral behavior of optical media. Applications. 3) Role of spectral conditions. Analytic properties of coherence functions in quantum optics. Reconstruction theorem.4) Phase retrieval problems. 5) Inverse scattering problems. 6) Solution of nonlinear evolution equations in optics by inverse scattering methods. Application to self-induced transparency. Causality in nonlinear wave propagation. 7) Analytic continuation in frequency and angular momentum. Complex singularities. Resonances and natural-mode expansions. Regge poles. 8) Wigner's causal inequality. Time delay. Spatial displacements in total reflection. 9) Analyticity in diffraction theory. Complex angular momentum theory of Mie scattering. Diffraction as a barrier tunnelling effect. Complex trajectories in optics. (Author) [pt

mediation: R Package for Causal Mediation Analysis

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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.

Causal asymmetry across cultures: Assigning causal roles in symmetric physical settings

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Andrea eBender

2011-09-01

Full Text Available In the cognitive sciences, causal cognition in the physical domain has featured as a core research topic, but the impact of culture has been rarely ever explored. One case in point for a topic on which this neglect is pronounced is the pervasive tendency of people to consider one of two (equally important entities as more important for bringing about an effect. In order to scrutinize how robust such tendencies are across cultures, we asked German and Tongan participants to assign prime causality in nine symmetric settings. For most settings, strong asymmetries in both cultures were found, but not always in the same direction, depending on the task content. This indicates that causal asymmetries, while indeed being a robust phenomenon across cultures, are also subject to culture-specific concepts. Moreover, the asymmetries were found to be modulated by figure-ground relations, but not by marking agency.

Entanglement, non-Markovianity, and causal non-separability

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Milz, Simon; Pollock, Felix A.; Le, Thao P.; Chiribella, Giulio; Modi, Kavan

2018-03-01

Quantum mechanics, in principle, allows for processes with indefinite causal order. However, most of these causal anomalies have not yet been detected experimentally. We show that every such process can be simulated experimentally by means of non-Markovian dynamics with a measurement on additional degrees of freedom. In detail, we provide an explicit construction to implement arbitrary a causal processes. Furthermore, we give necessary and sufficient conditions for open system dynamics with measurement to yield processes that respect causality locally, and find that tripartite entanglement and nonlocal unitary transformations are crucial requirements for the simulation of causally indefinite processes. These results show a direct connection between three counter-intuitive concepts: entanglement, non-Markovianity, and causal non-separability.

Amodal causal capture in the tunnel effect.

Science.gov (United States)

Bae, Gi Yeul; Flombaum, Jonathan I

2011-01-01

In addition to identifying individual objects in the world, the visual system must also characterize the relationships between objects, for instance when objects occlude one another or cause one another to move. Here we explored the relationship between perceived causality and occlusion. Can one perceive causality in an occluded location? In several experiments, observers judged whether a centrally presented event involved a single object passing behind an occluder, or one object causally launching another (out of view and behind the occluder). With no additional context, the centrally presented event was typically judged as a non-causal pass, even when the occluding and disoccluding objects were different colors--an illusion known as the 'tunnel effect' that results from spatiotemporal continuity. However, when a synchronized context event involved an unambiguous causal launch, participants perceived a causal launch behind the occluder. This percept of an occluded causal interaction could also be driven by grouping and synchrony cues in the absence of any explicitly causal interaction. These results reinforce the hypothesis that causality is an aspect of perception. It is among the interpretations of the world that are independently available to vision when resolving ambiguity, and that the visual system can 'fill in' amodally.

Space-time as a causal set

International Nuclear Information System (INIS)

Bombelli, L.; Lee, J.; Meyer, D.; Sorkin, R.D.

1987-01-01

We propose that space-time at the smallest scales is in reality a causal set: a locally finite set of elements endowed with a partial order corresponding to the macroscopic relation that defines past and future. We explore how a Lorentzian manifold can approximate a causal set, noting in particular that the thereby defined effective dimensionality of a given causal set can vary with length scale. Finally, we speculate briefly on the quantum dynamics of causal sets, indicating why an appropriate choice of action can reproduce general relativity in the classical limit

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.…

[Causal analysis approaches in epidemiology].

Science.gov (United States)

Dumas, O; Siroux, V; Le Moual, N; Varraso, R

2014-02-01

Epidemiological research is mostly based on observational studies. Whether such studies can provide evidence of causation remains discussed. Several causal analysis methods have been developed in epidemiology. This paper aims at presenting an overview of these methods: graphical models, path analysis and its extensions, and models based on the counterfactual approach, with a special emphasis on marginal structural models. Graphical approaches have been developed to allow synthetic representations of supposed causal relationships in a given problem. They serve as qualitative support in the study of causal relationships. The sufficient-component cause model has been developed to deal with the issue of multicausality raised by the emergence of chronic multifactorial diseases. Directed acyclic graphs are mostly used as a visual tool to identify possible confounding sources in a study. Structural equations models, the main extension of path analysis, combine a system of equations and a path diagram, representing a set of possible causal relationships. They allow quantifying direct and indirect effects in a general model in which several relationships can be tested simultaneously. Dynamic path analysis further takes into account the role of time. The counterfactual approach defines causality by comparing the observed event and the counterfactual event (the event that would have been observed if, contrary to the fact, the subject had received a different exposure than the one he actually received). This theoretical approach has shown limits of traditional methods to address some causality questions. In particular, in longitudinal studies, when there is time-varying confounding, classical methods (regressions) may be biased. Marginal structural models have been developed to address this issue. In conclusion, "causal models", though they were developed partly independently, are based on equivalent logical foundations. A crucial step in the application of these models is the

Repeated Causal Decision Making

Science.gov (United States)

Hagmayer, York; Meder, Bjorn

2013-01-01

Many of our decisions refer to actions that have a causal impact on the external environment. Such actions may not only allow for the mere learning of expected values or utilities but also for acquiring knowledge about the causal structure of our world. We used a repeated decision-making paradigm to examine what kind of knowledge people acquire in…

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…

Metodologia psicopatológica e ética em psicanálise: o princípio da alteridade hermética

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Nelson da Silva Junior

Full Text Available A compreensão da metapsicologia como sistema causal de representação da subjetividade exclui implicitamente a legitimidade do registro da ética como tal. Contra tal compreensão, apresentamos a noção de alteridade hermética enquanto um princípio da metodologia psicopatológica da psicanálise que não somente convive com a ética, mas ainda que solicita a independência e a transformação dos valores da normalidade.

Florística de lianas em um fragmento de floresta estacional semidecidual, Parque Estadual de Vassununga, Santa Rita do Passa Quatro, SP, Brasil Floristic of lianas in a fragment of seasonal semidecidual forest State Park of Vassununga, Santa Rita do Passa Quatro, São Paulo State, Brazil

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Yara Junqueira de Azevedo Tibiriçá

2006-06-01

Full Text Available Embora o conhecimento sobre a florística dos fragmentos de florestas estacionais semideciduais tenha crescido nos últimos anos, ainda sabe-se pouco sobre a comunidade de lianas (lenhosas ou herbáceas nesses fragmentos. Assim, foi realizado o levantamento florístico de lianas na gleba Maravilha, pertencente ao Parque Estadual de Vassununga (Santa Rita do Passa Quatro, SP, a fim de colaborar com o conhecimento dessa comunidade e subsidiar futuros trabalhos que envolvam essa forma de vida. A área de estudo compreende 127,08 ha, com inverno seco e temperatura média anual de 22 ºC. Para a coleta do material, percorreu-se mensalmente toda a borda do fragmento e três trilhas no interior da mata, de agosto/2002 a setembro/2003. Foram identificadas 120 espécies de lianas, pertencentes a 30 famílias e 71 gêneros, das quais 51% das espécies são volúveis, 42% apresentam gavinhas e apenas 7% são escandentes. As famílias mais representativas em número de espécies foram: Bignoniaceae (26, Malpighiaceae (14, Sapindaceae (12 e Asteraceae (9. Houve baixa similaridade florística entre as espécies de lianas presentes na gleba Maravilha em relação a outras áreas de florestas estacionais semideciduais do interior paulista.Although the knowledge about the floristic composition of the fragments of seasonal semidecidual forest had grown in the last few years, little is known about the liana communities (woody vines and herbaceous vines in those fragments. To collaborate with the knowledgement of the lianas and subsidize future works involving this life form, a floristic survey of the liana species occurring at the fragment Maravilha of the State Park of Vassununga (Santa Rita do Passa Quatro - SP was carried out. The study area comprised 127.08ha, with average temperature of 22 ºC. The whole border of the forest fragment and three tracks inside the forest were surveyed monthly between August 2002 and September 2003. One hundred and twenty species

Kant on causal laws and powers.

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Henschen, Tobias

2014-12-01

The aim of the paper is threefold. Its first aim is to defend Eric Watkins's claim that for Kant, a cause is not an event but a causal power: a power that is borne by a substance, and that, when active, brings about its effect, i.e. a change of the states of another substance, by generating a continuous flow of intermediate states of that substance. The second aim of the paper is to argue against Watkins that the Kantian concept of causal power is not the pre-critical concept of real ground but the category of causality, and that Kant holds with Hume that causal laws cannot be inferred non-inductively (that he accordingly has no intention to show in the Second analogy or elsewhere that events fall under causal laws). The third aim of the paper is to compare the Kantian position on causality with central tenets of contemporary powers ontology: it argues that unlike the variants endorsed by contemporary powers theorists, the Kantian variants of these tenets are resistant to objections that neo-Humeans raise to these tenets.

Análise florística e estrutural de sistemas silviagrícolas em Tomé-Açu, Pará.

OpenAIRE

BOLFE, E. L.; BATISTELLA, M.

2012-01-01

O objetivo deste trabalho foi analisar a composição florística e estrutural de sistemas silviagrícolas em Tomé-Açu, Pará. Os dados dendrométricos foram obtidos por inventário em 40 parcelas amostrais, com três unidades cada uma, no total de 120 unidades de 10x10 m. Foi inventariada a média de 1.424,3 indivíduos por hectare, pertencentes a 27 famílias e a 54 espécies. Tendo-se considerado a variabilidade dos estágios vegetativos, os diferentes sistemas silviagrícolas (SAF) foram divididos em q...

An Evaluation of Active Learning Causal Discovery Methods for Reverse-Engineering Local Causal Pathways of Gene Regulation

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Ma, Sisi; Kemmeren, Patrick; Aliferis, Constantin F.; Statnikov, Alexander

2016-01-01

Reverse-engineering of causal pathways that implicate diseases and vital cellular functions is a fundamental problem in biomedicine. Discovery of the local causal pathway of a target variable (that consists of its direct causes and direct effects) is essential for effective intervention and can facilitate accurate diagnosis and prognosis. Recent research has provided several active learning methods that can leverage passively observed high-throughput data to draft causal pathways and then refine the inferred relations with a limited number of experiments. The current study provides a comprehensive evaluation of the performance of active learning methods for local causal pathway discovery in real biological data. Specifically, 54 active learning methods/variants from 3 families of algorithms were applied for local causal pathways reconstruction of gene regulation for 5 transcription factors in S. cerevisiae. Four aspects of the methods’ performance were assessed, including adjacency discovery quality, edge orientation accuracy, complete pathway discovery quality, and experimental cost. The results of this study show that some methods provide significant performance benefits over others and therefore should be routinely used for local causal pathway discovery tasks. This study also demonstrates the feasibility of local causal pathway reconstruction in real biological systems with significant quality and low experimental cost. PMID:26939894

Repair of Partly Misspecified Causal Diagrams.

Science.gov (United States)

Oates, Chris J; Kasza, Jessica; Simpson, Julie A; Forbes, Andrew B

2017-07-01

Errors in causal diagrams elicited from experts can lead to the omission of important confounding variables from adjustment sets and render causal inferences invalid. In this report, a novel method is presented that repairs a misspecified causal diagram through the addition of edges. These edges are determined using a data-driven approach designed to provide improved statistical efficiency relative to de novo structure learning methods. Our main assumption is that the expert is "directionally informed," meaning that "false" edges provided by the expert would not create cycles if added to the "true" causal diagram. The overall procedure is cast as a preprocessing technique that is agnostic to subsequent causal inferences. Results based on simulated data and data derived from an observational cohort illustrate the potential for data-assisted elicitation in epidemiologic applications. See video abstract at, http://links.lww.com/EDE/B208.

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.

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...... to 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...

Causal inference in economics and marketing.

Science.gov (United States)

Varian, Hal R

2016-07-05

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.

Interactions of information transfer along separable causal paths

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Jiang, Peishi; Kumar, Praveen

2018-04-01

Complex systems arise as a result of interdependences between multiple variables, whose causal interactions can be visualized in a time-series graph. Transfer entropy and information partitioning approaches have been used to characterize such dependences. However, these approaches capture net information transfer occurring through a multitude of pathways involved in the interaction and as a result mask our ability to discern the causal interaction within a subgraph of interest through specific pathways. We build on recent developments of momentary information transfer along causal paths proposed by Runge [Phys. Rev. E 92, 062829 (2015), 10.1103/PhysRevE.92.062829] to develop a framework for quantifying information partitioning along separable causal paths. Momentary information transfer along causal paths captures the amount of information transfer between any two variables lagged at two specific points in time. Our approach expands this concept to characterize the causal interaction in terms of synergistic, unique, and redundant information transfer through separable causal paths. Through a graphical model, we analyze the impact of the separable and nonseparable causal paths and the causality structure embedded in the graph as well as the noise effect on information partitioning by using synthetic data generated from two coupled logistic equation models. Our approach can provide a valuable reference for an autonomous information partitioning along separable causal paths which form a causal subgraph influencing a target.

Does Causality Matter More Now? Increase in the Proportion of Causal Language in English Texts.

Science.gov (United States)

Iliev, Rumen; Axelrod, Robert

2016-05-01

The vast majority of the work on culture and cognition has focused on cross-cultural comparisons, largely ignoring the dynamic aspects of culture. In this article, we provide a diachronic analysis of causal cognition over time. We hypothesized that the increased role of education, science, and technology in Western societies should be accompanied by greater attention to causal connections. To test this hypothesis, we compared word frequencies in English texts from different time periods and found an increase in the use of causal language of about 40% over the past two centuries. The observed increase was not attributable to general language effects or to changing semantics of causal words. We also found that there was a consistent difference between the 19th and the 20th centuries, and that the increase happened mainly in the 20th century. © The Author(s) 2016.

Causality, spin, and equal-time commutators

International Nuclear Information System (INIS)

Abdel-Rahman, A.M.

1975-01-01

We study the causality constraints on the structure of the Lorentz-antisymmetric component of the commutator of two conserved isovector currents between fermion states of equal momenta. We discuss the sum rules that follow from causality and scaling, using the recently introduced refined infinite-momentum technique. The complete set of sum rules is found to include the spin-dependent fixed-mass sum rules obtained from light-cone commutators. The causality and scaling restrictions on the structure of the electromagnetic equal-time commutators are discussed, and it is found, in particular, that causality requires the spin-dependent part of the matrix element for the time-space electromagnetic equal-time commutator to vanish identically. It is also shown, in comparison with the electromagnetic case, that the corresponding matrix element for the time-space isovector current equal-time commutator is required, by causality, to have isospin-antisymmetric tensor and scalar operator Schwinger terms

Causal inference, probability theory, and graphical insights.

Science.gov (United States)

Baker, Stuart G

2013-11-10

Causal inference from observational studies is a fundamental topic in biostatistics. The causal graph literature typically views probability theory as insufficient to express causal concepts in observational studies. In contrast, the view here is that probability theory is a desirable and sufficient basis for many topics in causal inference for the following two reasons. First, probability theory is generally more flexible than causal graphs: Besides explaining such causal graph topics as M-bias (adjusting for a collider) and bias amplification and attenuation (when adjusting for instrumental variable), probability theory is also the foundation of the paired availability design for historical controls, which does not fit into a causal graph framework. Second, probability theory is the basis for insightful graphical displays including the BK-Plot for understanding Simpson's paradox with a binary confounder, the BK2-Plot for understanding bias amplification and attenuation in the presence of an unobserved binary confounder, and the PAD-Plot for understanding the principal stratification component of the paired availability design. Published 2013. This article is a US Government work and is in the public domain in the USA.

Causality as a Rigorous Notion and Quantitative Causality Analysis with Time Series

Science.gov (United States)

Liang, X. S.

2017-12-01

Given two time series, can one faithfully tell, in a rigorous and quantitative way, the cause and effect between them? Here we show that this important and challenging question (one of the major challenges in the science of big data), which is of interest in a wide variety of disciplines, has a positive answer. Particularly, for linear systems, the maximal likelihood estimator of the causality from a series X2 to another series X1, written T2→1, turns out to be concise in form: T2→1 = [C11 C12 C2,d1 — C112 C1,d1] / [C112 C22 — C11C122] where Cij (i,j=1,2) is the sample covariance between Xi and Xj, and Ci,dj the covariance between Xi and ΔXj/Δt, the difference approximation of dXj/dt using the Euler forward scheme. An immediate corollary is that causation implies correlation, but not vice versa, resolving the long-standing debate over causation versus correlation. The above formula has been validated with touchstone series purportedly generated with one-way causality that evades the classical approaches such as Granger causality test and transfer entropy analysis. It has also been applied successfully to the investigation of many real problems. Through a simple analysis with the stock series of IBM and GE, an unusually strong one-way causality is identified from the former to the latter 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 computer market. Another example presented here regards the cause-effect relation between the two climate modes, El Niño and Indian Ocean Dipole (IOD). In general, these modes are mutually causal, but the causality is asymmetric. To El Niño, the information flowing from IOD manifests itself as a propagation of uncertainty from the Indian Ocean. In the third example, an unambiguous one-way causality is found between CO2 and the global mean temperature anomaly. While it is confirmed that CO2 indeed drives the recent global warming

K-causality and degenerate spacetimes

Science.gov (United States)

Dowker, H. F.; Garcia, R. S.; Surya, S.

2000-11-01

The causal relation K+ was introduced by Sorkin and Woolgar to extend the standard causal analysis of C2 spacetimes to those that are only C0. Most of their results also hold true in the case of metrics with degeneracies which are C0 but vanish at isolated points. In this paper we seek to examine K+ explicitly in the case of topology-changing `Morse histories' which contain degeneracies. We first demonstrate some interesting features of this relation in globally Lorentzian spacetimes. In particular, we show that K+ is robust and the Hawking and Sachs characterization of causal continuity translates into a natural condition in terms of K+. We then examine K+ in topology-changing Morse spacetimes with the degenerate points excised and then for the Morse histories in which the degenerate points are reinstated. We find further characterizations of causal continuity in these cases.

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.

Causal localizations in relativistic quantum mechanics

Science.gov (United States)

Castrigiano, Domenico P. L.; Leiseifer, Andreas D.

2015-07-01

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.

ASSESSMENT OF THE QUALITY OF THE WATER OF FOUR JAGÜEYES IN THE STATE PARK “FLOR DEL BOSQUE”, PUEBLA, MEXICO

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Gabriela Pérez-Osorio

2016-01-01

Full Text Available The water supply is currently a problem, given the over-exploitation of groundwater and contamination of surface water, so it is important to find alternative supplies. The rain water harvesting is considered one of the most viable options for the supply of the vital liquid; some of the most utilized systems for this purpose are the jagüeyes. State Park General Lázaro Cárdenas del Río better known as "Flor del Bosque", it is located east of the city of Puebla and listed as Protected Natural Area, this park has jagüeyes which store water from rain. In this research, the main physicochemical and microbiological parameters of water stored in four jagüeyes of “Flor del Bosque” were measured according to Mexican regulations, in order to establish its quality and determine the uses that are given as a watering wooded areas and drinking trough do not represent a risk to the flora and fauna of the park. Composite samples of each jagüey were analyzed, during two dry weather stations and two rainy weather stations between the moths of November 2011 and October 2012. The water of the four jagüeyes has microbiological contamination by helminth eggs, Fasciola hepatica, fecal (180 CFU and total coliforms (475 CFU, this represents a risk to the health of wildlife; as well as lots of settleable and suspended solids. Since these systems have been installed for watering wooded areas and drinking trough of animals live there, it would be advisable before use be given appropriate treatment, plus it aims to improve its design or construction to be suitable for the intended uses.

Bayesian networks improve causal environmental ...

Science.gov (United States)

Rule-based weight of evidence approaches to ecological risk assessment may not account for uncertainties and generally lack probabilistic integration of lines of evidence. Bayesian networks allow causal inferences to be made from evidence by including causal knowledge about the problem, using this knowledge with probabilistic calculus to combine multiple lines of evidence, and minimizing biases in predicting or diagnosing causal relationships. Too often, sources of uncertainty in conventional weight of evidence approaches are ignored that can be accounted for with Bayesian networks. Specifying and propagating uncertainties improve the ability of models to incorporate strength of the evidence in the risk management phase of an assessment. Probabilistic inference from a Bayesian network allows evaluation of changes in uncertainty for variables from the evidence. The network structure and probabilistic framework of a Bayesian approach provide advantages over qualitative approaches in weight of evidence for capturing the impacts of multiple sources of quantifiable uncertainty on predictions of ecological risk. Bayesian networks can facilitate the development of evidence-based policy under conditions of uncertainty by incorporating analytical inaccuracies or the implications of imperfect information, structuring and communicating causal issues through qualitative directed graph formulations, and quantitatively comparing the causal power of multiple stressors on value

Hierarchical organisation of causal graphs

International Nuclear Information System (INIS)

Dziopa, P.

1993-01-01

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

Dynamics and causality constraints

International Nuclear Information System (INIS)

Sousa, Manoelito M. de

2001-04-01

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)

Causal uncertainty, claimed and behavioural self-handicapping.

Science.gov (United States)

Thompson, Ted; Hepburn, Jonathan

2003-06-01

Causal uncertainty beliefs involve doubts about the causes of events, and arise as a consequence of non-contingent evaluative feedback: feedback that leaves the individual uncertain about the causes of his or her achievement outcomes. Individuals high in causal uncertainty are frequently unable to confidently attribute their achievement outcomes, experience anxiety in achievement situations and as a consequence are likely to engage in self-handicapping behaviour. Accordingly, we sought to establish links between trait causal uncertainty, claimed and behavioural self-handicapping. Participants were N=72 undergraduate students divided equally between high and low causally uncertain groups. We used a 2 (causal uncertainty status: high, low) x 3 (performance feedback condition: success, non-contingent success, non-contingent failure) between-subjects factorial design to examine the effects of causal uncertainty on achievement behaviour. Following performance feedback, participants completed 20 single-solution anagrams and 12 remote associate tasks serving as performance measures, and 16 unicursal tasks to assess practice effort. Participants also completed measures of claimed handicaps, state anxiety and attributions. Relative to low causally uncertain participants, high causally uncertain participants claimed more handicaps prior to performance on the anagrams and remote associates, reported higher anxiety, attributed their failure to internal, stable factors, and reduced practice effort on the unicursal tasks, evident in fewer unicursal tasks solved. These findings confirm links between trait causal uncertainty and claimed and behavioural self-handicapping, highlighting the need for educators to facilitate means by which students can achieve surety in the manner in which they attribute the causes of their achievement outcomes.

Estabelecimento de meio de cultura e quantificação da germinação de grãos de pólen de cultivares de marmeleiros

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Carolina Ruiz Zambon

2014-06-01

Full Text Available Visando a dar suporte aos trabalhos de melhoramento genético do marmeleiro (Cydoniaoblonga Mill., voltados para a seleção de cultivares altamente produtivas, aptas a serem cultivadas em regiões subtropicais e produtoras de doces de qualidade superior, objetivou-se ajustar o meio de cultura básico para a germinação de grãos de pólen de diferentes cultivares dessa espécie e quantificar o número de estames, número de grãos de pólen por antera e por flor. O pólen utilizado foi da cultivar Portugal, obtido de anteras provenientes de flores em estádio de balão. Em seguida, com auxílio de um pincel, os grãos de pólen foram espalhados sobre a superfície de placas de Petri, contendo 20 mL de meio de cultura, de acordo com os seguintes experimentos: 1 concentrações de ágar (4; 6; 8 e 10 g L-1 e valores de pH (3,5; 4,5; 5,5 e 6,5; 2 concentrações de sacarose (0; 30; 60 e 90 g L-1; 3 concentrações de nitrato de cálcio (0; 200; 400 e 800 mg L-1; 4 concentrações de ácido bórico (0; 400; 800 e 1.200 mg L-1; e 5 tempo de emissão do tubo polínico (0; 1; 2; 3; 4; 5 e 6 horas após a inoculação, os quais foram montados de forma sequencial. Após, avaliou-se a taxa de germinação dos grãos de pólen das 27 cultivares (Alaranjado, Alongado, Apple, BA29, Bereckzy, Champion, Cheldow, Constantinopla, CTS 207, Dangers, De Patras, De Vranja, Dulot, Fuller, Mendoza INTA 37, Kiakami, Lajeado, Meeck Profilic, Meliforme, Pineapple, Portugal, Provence, Radaelli, Rea's Mamouth, Smyrna, Van Deman e Zuquerineta, além do número de estames, número de grãos de pólen por antera e por flor. Realizando-se as leituras da porcentagem de germinação após cinco horas de incubação, conclui-se que o meio de cultura para a germinação de grãos de pólen do marmeleiro deve ser acrescido de 68 g L-1 de sacarose e 366 mg L-1 de ácido bórico, sendo o pH aferido para 5,8 e o meio solidificado com 10 g L-1 de ágar. Foram constatadas diferen

Causal knowledge and reasoning in decision making

NARCIS (Netherlands)

Hagmayer, Y.; Witteman, C.L.M.

2017-01-01

Normative causal decision theories argue that people should use their causal knowledge in decision making. Based on these ideas, we argue that causal knowledge and reasoning may support and thereby potentially improve decision making based on expected outcomes, narratives, and even cues. We will

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…

Links between causal effects and causal association for surrogacy evaluation in a gaussian setting.

Science.gov (United States)

Conlon, Anna; Taylor, Jeremy; Li, Yun; Diaz-Ordaz, Karla; Elliott, Michael

2017-11-30

Two paradigms for the evaluation of surrogate markers in randomized clinical trials have been proposed: the causal effects paradigm and the causal association paradigm. Each of these paradigms rely on assumptions that must be made to proceed with estimation and to validate a candidate surrogate marker (S) for the true outcome of interest (T). We consider the setting in which S and T are Gaussian and are generated from structural models that include an unobserved confounder. Under the assumed structural models, we relate the quantities used to evaluate surrogacy within both the causal effects and causal association frameworks. We review some of the common assumptions made to aid in estimating these quantities and show that assumptions made within one framework can imply strong assumptions within the alternative framework. We demonstrate that there is a similarity, but not exact correspondence between the quantities used to evaluate surrogacy within each framework, and show that the conditions for identifiability of the surrogacy parameters are different from the conditions, which lead to a correspondence of these quantities. Copyright © 2017 John Wiley & Sons, Ltd.

Non-Gaussian Methods for Causal Structure Learning.

Science.gov (United States)

Shimizu, Shohei

2018-05-22

Causal structure learning is one of the most exciting new topics in the fields of machine learning and statistics. In many empirical sciences including prevention science, the causal mechanisms underlying various phenomena need to be studied. Nevertheless, in many cases, classical methods for causal structure learning are not capable of estimating the causal structure of variables. This is because it explicitly or implicitly assumes Gaussianity of data and typically utilizes only the covariance structure. In many applications, however, non-Gaussian data are often obtained, which means that more information may be contained in the data distribution than the covariance matrix is capable of containing. Thus, many new methods have recently been proposed for using the non-Gaussian structure of data and inferring the causal structure of variables. This paper introduces prevention scientists to such causal structure learning methods, particularly those based on the linear, non-Gaussian, acyclic model known as LiNGAM. These non-Gaussian data analysis tools can fully estimate the underlying causal structures of variables under assumptions even in the presence of unobserved common causes. This feature is in contrast to other approaches. A simulated example is also provided.

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...

La descentralización a la luz del caso Bella Flor en Ciudad Bolívar, Bogotá

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Pening G Jean Philippe

2005-12-01

Full Text Available En Colombia, las políticas de descentralización se profundizaron con la Constitución Política de 1991 y los desarrollos legislativos posteriores. A los municipios se les devolvió la responsabilidad en inversiones en sectores como educación, salud y agua potable y saneamiento básico. Bogotá presenta los mejores indicadores colombianos, sin embargo en la ciudad conviven hogares que presentan indicadores bastante alejados del promedio de la localidad, de la ciudad y del país. Para demostrarlo, se realizó un censo en el barrio Bella Flor de la localidad de Ciudad Bolívar en Bogotá, el cual arroja unos resultados que comparamos con un censo realizado en 2000 y con resultados de encuestas del DANE.

Illness causal beliefs in Turkish immigrants

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Klimidis Steven

2007-07-01

Full Text Available Abstract Background People hold a wide variety of beliefs concerning the causes of illness. Such beliefs vary across cultures and, among immigrants, may be influenced by many factors, including level of acculturation, gender, level of education, and experience of illness and treatment. This study examines illness causal beliefs in Turkish-immigrants in Australia. Methods Causal beliefs about somatic and mental illness were examined in a sample of 444 members of the Turkish population of Melbourne. The socio-demographic characteristics of the sample were broadly similar to those of the Melbourne Turkish community. Five issues were examined: the structure of causal beliefs; the relative frequency of natural, supernatural and metaphysical beliefs; ascription of somatic, mental, or both somatic and mental conditions to the various causes; the correlations of belief types with socio-demographic, modernizing and acculturation variables; and the relationship between causal beliefs and current illness. Results Principal components analysis revealed two broad factors, accounting for 58 percent of the variation in scores on illness belief scales, distinctly interpretable as natural and supernatural beliefs. Second, beliefs in natural causes were more frequent than beliefs in supernatural causes. Third, some causal beliefs were commonly linked to both somatic and mental conditions while others were regarded as more specific to either somatic or mental disorders. Last, there was a range of correlations between endorsement of belief types and factors defining heterogeneity within the community, including with demographic factors, indicators of modernizing and acculturative processes, and the current presence of illness. Conclusion Results supported the classification of causal beliefs proposed by Murdock, Wilson & Frederick, with a division into natural and supernatural causes. While belief in natural causes is more common, belief in supernatural causes

Illness causal beliefs in Turkish immigrants.

Science.gov (United States)

Minas, Harry; Klimidis, Steven; Tuncer, Can

2007-07-24

People hold a wide variety of beliefs concerning the causes of illness. Such beliefs vary across cultures and, among immigrants, may be influenced by many factors, including level of acculturation, gender, level of education, and experience of illness and treatment. This study examines illness causal beliefs in Turkish-immigrants in Australia. Causal beliefs about somatic and mental illness were examined in a sample of 444 members of the Turkish population of Melbourne. The socio-demographic characteristics of the sample were broadly similar to those of the Melbourne Turkish community. Five issues were examined: the structure of causal beliefs; the relative frequency of natural, supernatural and metaphysical beliefs; ascription of somatic, mental, or both somatic and mental conditions to the various causes; the correlations of belief types with socio-demographic, modernizing and acculturation variables; and the relationship between causal beliefs and current illness. Principal components analysis revealed two broad factors, accounting for 58 percent of the variation in scores on illness belief scales, distinctly interpretable as natural and supernatural beliefs. Second, beliefs in natural causes were more frequent than beliefs in supernatural causes. Third, some causal beliefs were commonly linked to both somatic and mental conditions while others were regarded as more specific to either somatic or mental disorders. Last, there was a range of correlations between endorsement of belief types and factors defining heterogeneity within the community, including with demographic factors, indicators of modernizing and acculturative processes, and the current presence of illness. Results supported the classification of causal beliefs proposed by Murdock, Wilson & Frederick, with a division into natural and supernatural causes. While belief in natural causes is more common, belief in supernatural causes persists despite modernizing and acculturative influences. Different

Covariation in Natural Causal Induction.

Science.gov (United States)

Cheng, Patricia W.; Novick, Laura R.

1991-01-01

Biases and models usually offered by cognitive and social psychology and by philosophy to explain causal induction are evaluated with respect to focal sets (contextually determined sets of events over which covariation is computed). A probabilistic contrast model is proposed as underlying covariation computation in natural causal induction. (SLD)

Exploring Individual Differences in Preschoolers' Causal Stance

Science.gov (United States)

Alvarez, Aubry; Booth, Amy E.

2016-01-01

Preschoolers, as a group, are highly attuned to causality, and this attunement is known to facilitate memory, learning, and problem solving. However, recent work reveals substantial individual variability in the strength of children's "causal stance," as demonstrated by their curiosity about and preference for new causal information. In…

ANÁLISE DE RELATÓRIOS AMBIENTAIS PRÉVIOS DE CURITIBA/PR COM BASE NOS PRINCÍPIOS DO PLANEJAMENTO DA PAISAGEM

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Laura Freire Estêvez

2015-09-01

Full Text Available O Planejamento da Paisagem aplicado ao meio urbanizado tem como um dos princípios a manutenção ou melhoria da qualidade ambiental urbana, que pode ser diminuída com a crescente instalação de empreendimentos na cidade. Para avaliar os impactos ambientais desses empreendimentos antes da sua instalação, o Estatuto da Cidade (BRASIL, 2001 instituiu o Estudo Prévio de Impacto de Vizinhança - EIV. O Município de Curitiba realiza estudos de impactos ambientais de empreendimentos e suas atividades desde 1997 com o estabelecimento do Relatório Ambiental Prévio – RAP (CURITIBA, 1997. O objetivo do trabalho foi analisar RAPs elaborados em Curitiba, PR, com base nos princípios do Planejamento da Paisagem e com isso fornecer subsídios para a reflexão sobre a possibilidade de um planejamento urbano que considere a qualidade ambiental. Para a avaliação dos RAPs foram definidos critérios e parâmetros, com base nos estudos de qualidade ambiental urbana, nos estudos sobre cidades saudáveis da Organização Mundial da Saúde e em princípios da Flor da Permacultura. Os critérios definidos foram: Espaços Livres, Cobertura Vegetal, Verticalidade das Edificações, Usos Potencialmente Poluidores, Estilos de Vida Saudável e Pegada Ecológica. Apesar de tratar sobre alguns impactos ambientais negativos de forma superficial, os RAPs não contemplam a grande maioria dos impactos ambientais negativos relacionados à qualidade ambiental urbana e, mesmo assim, forneceram diagnósticos favoráveis à instalação dos empreendimentos. Esse diagnóstico foi aceito pelo poder público que permitiu a instalação dos empreendimentos, que resultaram em diminuição da qualidade ambiental urbana.

Behavioural Pattern of Causality Parameter of Autoregressive ...

African Journals Online (AJOL)

In this paper, a causal form of Autoregressive Moving Average process, ARMA (p, q) of various orders and behaviour of the causality parameter of ARMA model is investigated. It is deduced that the behaviour of causality parameter ψi depends on positive and negative values of autoregressive parameter φ and moving ...

Nascentes da sub-bacia hidrográfica do rio Poxim, estado de Sergipe: da degradação à restauração

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Robério Anastácio Ferreira

2011-04-01

Full Text Available Estudos ambientais em bacias hidrográficas são fundamentais para o entendimento do uso dos recursos naturais e dos problemas relacionados à ocupação do espaço. Em Sergipe, há necessidade de se obter informações para fins de planejamento e gestão futura de suas bacias hidrográficas, uma vez que gradualmente observa-se uma redução do volume produzido nos cursos d'água e da qualidade de suas águas, que são imprescindíveis para o abastecimento humano, a utilização na agricultura e na indústria. Devido ao acelerado processo de supressão da vegetação na sub-bacia hidrográfica do rio Poxim, formada pelos rios Poxim-mirim, Poxim-açu, e Pitanga e seus pequenos tributários, foi realizado um diagnóstico para se verificar o estado de conservação das suas principais nascentes, a situação quanto ao fluxo de água, as formas de uso e ocupação do solo no entorno destas e os tipos fisionômicos de vegetação remanescentes. As informações obtidas serão úteis para a realização de projetos de restauração ambiental, a promoção de melhorias no ambiente e nas comunidades rurais e resgate da diversidade da flora e fauna nestas áreas. Observou-se que as 20 principais nascentes dos rios e tributários que compõem a sub-bacia hidrográfica do rio Poxim, apresentam alterações decorrentes da acelerada antropização (90%, a maioria delas (65% com elevada degradação (sem raio mínimo de 50m de vegetação e ocupadas por agricultura (50% e pastagens (35%. Somente duas nascentes encontram-se preservadas. Quanto à composição florística, as espécies identificadas (43 podem ser utilizadas em projetos futuros para restauração das nascentes e dos cursos d'água nesta sub-bacia hidrográfica.

Tachyons and causal paradoxes

International Nuclear Information System (INIS)

Maund, J.B.

1979-01-01

Although the existence of tachyons is not ruled out by special relativity, it appears that causal paradoxes will arise if there are tachyons. The usual solutions to these paradoxes employ some form of the reinterpretation principle. In this paper it is argued first that, the principle is incoherent, second, that even if it is not, some causal paradoxes remain, and third, the most plausible ''solution,'' which appeals to boundary conditions of the universe, will conflict with special relativity

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

Directory of Open Access Journals (Sweden)

York eHagmayer

2014-11-01

Full Text Available 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 literature review on causal beliefs about depression was conducted, including original, quantitative research. Thirty-six studies investigating 13 non-Western and 32 Western cultural groups were analysed by classifying assumed causes and preferred forms of treatment into common categories. Relations between beliefs and treatment preferences were assessed. Substantial agreement between cultural groups was found with respect to the impact of observable causes. Stress was generally rated as most important. Less agreement resulted for hidden, especially supernatural causes. Causal beliefs were clearly related to treatment preferences in Western groups, while evidence was mostly lacking for non-Western groups. Overall predictions were supported, but there were considerable methodological limitations. Pointers to future research, which may combine studies on causal beliefs with experimental paradigms on causal reasoning, are given.

El efecto del pastoreo sobre la diversidad florística y estructural en pastizales de montaña del centro de Argentina Grazing effects on the floristic and structural diversity in mountain grasslands from central Argentina

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MARIANA NAI-BREGAGLIO

2002-09-01

Full Text Available Se estudió el efecto del pastoreo y de su exclusión por 10 años sobre la composición y diversidad florística y sobre la diversidad estructural de pastizales naturales de montaña, en las Sierras de Córdoba (2.200 m de altitud, Argentina. Consideramos diversidad estructural a la complejidad en la disposición de la biomasa en el espacio horizontal y vertical. Se estimó la abundancia de todas las especies de plantas y su arreglo en el espacio vertical y horizontal, por medio de 50 agujas distribuidas al azar, subdivididas en intervalos verticales de 20 cm. El muestreo se realizó en el interior de cinco réplicas, cada una de las cuales consistió de dos parcelas adyacentes de 20 x 20 m separadas por un alambrado, una pastoreada y otra excluida al pastoreo. Se estimaron índices de diversidad de Shannon para la composición florística y para la estructura vertical. Para analizar las posibles variaciones entre tratamientos en la distribución horizontal de la diversidad de especies y de la diversidad de estratos verticales, se compararon las varianzas de los índices de diversidad florística y de la estructura vertical, respectivamente. La riqueza de especies y la diversidad florística alcanzaron valores máximos en sitios pastoreados. Más del 85 % del total de especies se registraron en estos sitios en contraste con un 65 % presente en los sitios excluidos al ganado. Sólo se registraron tres especies de plantas exóticas, una de ellas exclusiva de los sitios pastoreados. El pastoreo produjo una disminución significativa de la diversidad de estratos verticales y de la varianza en el espacio horizontal del índice de diversidad florística, pero no produjo cambios significativos en la varianza en el espacio horizontal del índice de diversidad de estratos verticales. Si bien el pastoreo promueve la formación de céspedes de alta diversidad florística, produce, además, una simplificación de la estructura comunitaria, tanto en sentido

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

Identity, causality, and pronoun ambiguity.

Science.gov (United States)

Sagi, Eyal; Rips, Lance J

2014-10-01

This article looks at the way people determine the antecedent of a pronoun in sentence pairs, such as: Albert invited Ron to dinner. He spent hours cleaning the house. The experiment reported here is motivated by the idea that such judgments depend on reasoning about identity (e.g., the identity of the he who cleaned the house). Because the identity of an individual over time depends on the causal-historical path connecting the stages of the individual, the correct antecedent will also depend on causal connections. The experiment varied how likely it is that the event of the first sentence (e.g., the invitation) would cause the event of the second (the house cleaning) for each of the two individuals (the likelihood that if Albert invited Ron to dinner, this would cause Albert to clean the house, versus cause Ron to clean the house). Decisions about the antecedent followed causal likelihood. A mathematical model of causal identity accounted for most of the key aspects of the data from the individual sentence pairs. Copyright © 2014 Cognitive Science Society, Inc.

Composição, diversidade e similaridade florística de uma floresta tropical semidecídua submontana em Marcelândia - MT

OpenAIRE

Ferreira Júnior,Elbert Viana; Soares,Thelma Shirlen; Costa,Marcus Filipe Fernandes da; Moraes e Silva,Versides Sebastião

2008-01-01

O objetivo deste estudo foi avaliar a composição, diversidade e similaridade florística de uma área de floresta estacional semidecidual localizada no município de Marcelândia-MT, em área de tensão ecológica, na região de contato floresta ombrófila/floresta estacional. Foram amostrados 4008 indivíduos, pertencentes a 33 famílias e 92 espécies, em 74 parcelas de 10 m x 250 m. As famílias que apresentaram maior valor percentual de árvores foram: Lauraceae (15,99%), Melastomataceae (12,97%), Sapo...

A Causal Theory of Modality

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José Tomás Alvarado

2009-08-01

Full Text Available This work presents a causal conception of metaphysical modality in which a state of affairs is metaphysically possible if and only if it can be caused (in the past, the present or the future by current entities. The conception is contrasted with what is called the “combinatorial” conception of modality, in which everything can co-exist with anything else. This work explains how the notion of ‘causality’ should be construed in the causal theory, what difference exists between modalities thus defined from nomological modality, how accessibility relations between possible worlds should be interpreted, and what is the relation between the causal conception and the necessity of origin.

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

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.

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.

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

Polimorfismo floral em Valeriana scandens L. (Valerianaceae Floral polymorphism in Valeriana scandens L. (Valerianaceae

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Erica Duarte-Silva

2010-09-01

Full Text Available Foram encontrados três morfos florais em Valeriana scandens L.: flor perfeita, flor pistilada 1 e flor pistilada 2. A perfeita possui corola maior que a dos demais morfos, com lobos reflexos na antese, giba proeminente e localizada na porção proximal do tubo floral; anteras maiores que as dos demais morfos, com pólen viável; estilete curto e estigma incluso, o menor ovário e saco embrionário estruturalmente normal, semelhante ao dos demais morfos. A pistilada 1 possui a giba menos proeminente, corola de tamanho intermediário em relação aos demais morfos, lobos radiais na antese; anteras pequenas, sem pólen e estilete longo e estigma exserto. A pistilada 2 possui lobos radiais na antese, anteras de comprimento semelhante às da perfeita, mas de menor largura, com pólen inviável; estilete mais curto, tal como o da flor perfeita, e estigma exserto, tal como o da flor pistilada 1. Nos três morfos, o nectário é formado por tricomas secretores unicelulares situados na epiderme da face interna da giba, e suas sementes são viáveis. As flores pistilada 2 e perfeita apresentam um septo que isola a giba do restante do tubo floral, formando uma câmara nectarífera. V. scandens L. é ginomonóica-ginodióica, expressão sexual inédita em Valerianaceae.Three floral morphs were found in Valeriana scandens L.: perfect, pistillate 1, and pistillate 2. In perfect flowers, the corolla is longer than in the other morphs, with reflexed lobes at anthesis and a prominent gibbus at the tube base; anthers are longer and contain viable pollen grains; the pistil has a short included style/stigma and the smallest ovary, but a structurally normal embryo sac similar to that of the other morphs. In pistillate 1 flowers, the corolla is intermediate in size, and has radially displayed lobes at anthesis, and a softly prominent gibbus; anthers are small and devoid of pollen; the pistil shows a long exerted style/stigma. In pistillate 2 flowers, the corolla

Evaluación del conocimiento florístico de la cordillera Cantábrica (España a partir de bases de datos de biodiversidad

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Jiménez-Alfaro, B.

2009-12-01

un requisito fundamental para la conservación de cualquier región, y las bases de datos biológicas representan una herramienta básica para la estimación de medidas de diversidad. Sin embargo, muchas regiones biogeográficas fragmentadas administrativamente suelen estar caracterizadas por bases de datos heterogéneas realizadas desde diferentes instituciones y a diferentes escalas. En este trabajo se evalúa el conocimiento florístico de plantas vasculares aportado por bases de datos regionales en la Cordillera Cantábrica (España. Se utilizaron los datos georeferenciados de bases de datos no superpuestas, provenientes de una colección de herbario y de un atlas completado con información bibliográfica, los cuales fueron comparados en función de los patrones temporales y espaciales (cuadrículas UTM de 10x10 km de riqueza florística, utilizando estimadores no paramétricos (ICE, Chao2, Jack1 y Jack2 para medir el grado de conocimiento que las bases de datos reflejan. Ambas fuentes fueron también comparadas con una base de datos nacional con información sobre todo el área de estudio. Las bases de datos regionales detectaron unos patrones similares de prospección histórica y espacial, y los valores de riqueza florística observada estuvieron altamente correlacionados con la base de datos nacional, si bien se detectó una elevada heterogeneidad en la riqueza conocida por UTM. Las estimaciones de riqueza florística indicaron que ambas bases de datos están incompletas, aunque permitieron realizar una estimación de la riqueza total de la Cordillera Cantábrica (en torno a 3590 especies y subespecies. Los resultados obtenidos sugieren que bases de datos incompletas, parciales y de diferente naturaleza pueden aportar información similar para la detección de áreas poco prospectadas, aunque la incorporación de referencias bibliográficas a las bases de datos de herbarios puede ofrecer mejores estimaciones de riqueza florística. Sin embargo, una valoraci

Alterações na composição florística das algas da Praia de Boa Viagem (Niterói, RJ)

OpenAIRE

TAOUIL, ANDRÉ; YONESHIGUE-VALENTIN, YOCIE

2002-01-01

A Baía de Guanabara no decorrer da ocupação de suas margens sofreu uma continua degradação, levando-a a grandes modificações em seu entorno e a inúmeros danos ambientais. Além de uma significativa alteração paisagística, ocorreu também uma queda na qualidade de suas águas, devido ao lançamento de grande quantidade de efluentes não tratados (domésticos e industriais). Este trabalho teve como objetivo inventariar a flora algácea da praia de Boa Viagem (Niterói, RJ), compará-la com levantamentos...

Classificação fitogeográfica das florestas do Alto Rio Xingu Phytogeographical classification of the Upper Xingu River forest

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Natália Macedo Ivanauskas

2008-01-01

Full Text Available Este trabalho propõe a inclusão da categoria Floresta Estacional Perenifólia no sistema oficial de classificação da vegetação brasileira, devido às particularidades florísticas e fisionômicas da floresta da borda sul-amazônica, que atinge maior amplitude geográfica na região do Alto Rio Xingu. Para justificar essa inclusão são apresentadas as características ambientais (clima, solo, hidrologia e diferenças fisionômicas e florísticas entre as florestas do Alto Xingu e demais florestas ombrófilas da Bacia do Amazonas e estacionais do Planalto Central.This paper proposes the inclusion of the "Evergreen Seasonal Forest" category in the official system used to classify Brazilian forests. This proposal is based upon the floristic and physiognomic particularities of the Southern Amazonian forest, which reach a greater magnitude around the Upper Xingu River. In order to justify the inclusion, the paper reports environmental characteristics (climate, soil and hydrology as well as floristic and physiognomic differences between the Upper Xingu River forest and both the Ombrophilous Forest from the Amazon Basin and the Seasonal Forest of the Central Plateau.

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....... This might lead us to find heterogeneous effects when the true effect is homogenous, or to wrongly estimate not only the magnitude but also the sign of heterogeneous effects. We apply a test for the robustness of heterogeneous causal effects in the face of varying degrees and patterns of selection bias...

Levantamento florístico no cerrado de Pedregulho, SP, Brasil Floristic inventory of cerrado at Pedregulho, São Paulo State, Brazil

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Denise Sasaki

2008-03-01

Full Text Available Em Pedregulho, município do extremo nordeste do Estado de São Paulo, ocorrem fragmentos de cerrado considerados floristicamente distintos dos demais remanescentes paulistas. Nesse estudo, foi realizado um levantamento florístico em Pedregulho, abordando duas regiões geologicamente distintas: o Parque Estadual das Furnas do Bom Jesus e o distrito de Estreito. Em cada uma, delimitaram-se duas parcelas de 50×50 m, totalizando um hectare, onde foram encontradas 65 famílias e 379 espécies de angiospermas. Coletas em áreas adjacentes totalizaram 71 famílias e 443 espécies. As duas regiões estudadas têm baixa similaridade florística entre si. A distribuição geográfica das espécies é analisada e oito padrões são delimitados para aquelas cuja distribuição no Estado de São Paulo é restrita à região de Pedregulho.Pedregulho municipality in the far northeastern region of São Paulo state has fragments of cerrado vegetation thought to be floristically distinct from other cerrado remmants in the state. In this study, a floristic survey was carried out at Pedregulho, focusing on two geologically distinct regions: Furnas do Bom Jesus State Park and the Estreito district. In each region, 50×50 m plots were set up for a total sample area of 1 hectare, where 65 families and 379 angiosperm species were recorded. Collecting efforts in adjacent areas resulted in a total of 71 families and 443 species. The two study areas had low floristic similarity. Geographic species distribution was analyzed and eight patterns were defined for those species restricted to the Pedregulho region in São Paulo.

Contribuição da caatinga na sustentabilidade de projetos de assentamentos no sertão norte-rio-grandense Caatinga forest contribution to the sustainability of settlement projects on rio grande do norte backwoods

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Márcio Rocha Francelino

2003-02-01

Full Text Available Os objetivos deste trabalho foram caracterizar os recursos florestais da caatinga e determinar a sua contribuição na sustentabilidade em projetos de reforma agrária localizados na região oeste do Estado do Rio Grande do Norte. Foi realizado um levantamento florístico, no qual se constatou que as espécies mais bem distribuídas pelas unidades amostrais foram as de caráter pioneiro, indicando que essas matas já foram exploradas anteriormente à ocupação dos assentados. O estrato florestal mais comum foi o arbustivo-arbóreo fechado, correspondendo a 75% da parcelas amostradas. Os assentamentos com presença de cobertura florestal do tipo arbustivo-arbórea aberta apresentaram baixa densidade, associada à baixa diversidade florística e à forte tendência à homogeneização, o que as enquadra como prioritárias em um processo de conservação e, ou, enriquecimento da flora. Devido à baixa rentabilidade da exploração dos recursos florestais da caatinga, essa atividade deveria servir apenas como complemento de renda dos assentados, já que outras atividades apresentam maiores retornos econômicos. Entretanto, ela possui grande importância no contexto social, sendo fundamental para a sustentabilidade dos assentamentos estudados.A floristic survey was conducted to characterize the caatinga forest resources as well as to determine its contribution to the sustainability agrarian reform projects in western Rio Grande do Norte. This survey showed that the pioneer species were better distributed in the sampling units, indicating that these forests had been explored prior to occupation by the settlers. The closed arboreal-shruby type was the most common forest stratum, and corresponded to 75% of the sampled plots. The settlements with forest cover of the open arboreal-shruby type presented low density associated with a low floristic diversity as well as a marked tendency to homogenization, making this forest cover a priority for conservation

Entanglement entropy in causal set theory

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Sorkin, Rafael D.; Yazdi, Yasaman K.

2018-04-01

Entanglement entropy is now widely accepted as having deep connections with quantum gravity. It is therefore desirable to understand it in the context of causal sets, especially since they provide in a natural manner the UV cutoff needed to render entanglement entropy finite. Formulating a notion of entanglement entropy in a causal set is not straightforward because the type of canonical hypersurface-data on which its definition typically relies is not available. Instead, we appeal to the more global expression given in Sorkin (2012 (arXiv:1205.2953)) which, for a Gaussian scalar field, expresses the entropy of a spacetime region in terms of the field’s correlation function within that region (its ‘Wightman function’ W(x, x') ). Carrying this formula over to the causal set, one obtains an entropy which is both finite and of a Lorentz invariant nature. We evaluate this global entropy-expression numerically for certain regions (primarily order-intervals or ‘causal diamonds’) within causal sets of 1  +  1 dimensions. For the causal-set counterpart of the entanglement entropy, we obtain, in the first instance, a result that follows a (spacetime) volume law instead of the expected (spatial) area law. We find, however, that one obtains an area law if one truncates the commutator function (‘Pauli–Jordan operator’) and the Wightman function by projecting out the eigenmodes of the Pauli–Jordan operator whose eigenvalues are too close to zero according to a geometrical criterion which we describe more fully below. In connection with these results and the questions they raise, we also study the ‘entropy of coarse-graining’ generated by thinning out the causal set, and we compare it with what one obtains by similarly thinning out a chain of harmonic oscillators, finding the same, ‘universal’ behaviour in both cases.

Preschoolers prefer to learn causal information

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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.

Composição florística e estrutura da comunidade de plantas do estrato herbáceo em áreas de cultivo de árvores frutíferas Floristic composition and community structure of understory vegetation in orchard

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Yuriko A. N. P. Yanagizawa

1999-12-01

Full Text Available O objetivo do presente trabalho foi caracterizar, em três épocas, a comunidade de plantas presentes em áreas de cultivo de abacateiro e de nogueira pecan, localizadas na Fazenda Experimental Lageado, da FCA-UNESP, município de Botucatu-SP. Em decorrência da arquitetura da copa e do caráter decíduo das nogueiras, esta área apresenta-se mais ensolarada, o que produz condições ambientais diferentes entre as duas áreas estudadas. Foi estabelecida uma grade retangular composta de 55 parcelas quadradas, contíguas, com 5 m de lado, havendo 40 parcelas sob os abacateiros e 15 sob as nogueiras. As coletas foram realizadas em março, maio e agosto de 1993, quando foram sorteados quadrados de 1x 1 m em cada parcela, de forma a não haver coincidência entre as amostragens realizadas em cada época. Foram levantadas as espécies ocorrentes, sua porcentagem de cobertura e freqüência. Os dados foram analisados através de métodos multivariados, utilizando-se a Análise de Agrupamento para as seis situações (3 épocas x 2 ambientes. Foram coletadas, no total, 54 espécies, distribuídas em 38 gêneros e 19 famílias, sendo Asteraceae e Poaceae as que contribuíram com o maior número de espécies. A riqueza em espécies foi maior na área sob as nogueiras; em ambas as áreas, a riqueza foi maior na estação úmida. Sob os abacateiros, a porcentagem de cobertura total da comunidade apresentou pouca variação temporal, diferindo da área sob as nogueiras onde se observou flutuação deste parâmetro. O padrão de distribuição espacial, para quase todas as populações, foi do tipo agrupado. A similaridade florística foi maior entre as duas áreas dentro de cada época de coleta. A presença constante de espécies como Commelina nudiflora que contribuiu com valores elevados de cobertura nas três épocas de coleta, mostra a necessidade de utilizar métodos de controle permanentes na área do pomar estudado.The main goal of this study was to

Mathematical implications of Einstein-Weyl causality

International Nuclear Information System (INIS)

Borchers, H.J.; Sen, R.N.

2006-01-01

The present work is the first systematic attempt at answering the following fundamental question: what mathematical structures does Einstein-Weyl causality impose on a point-set that has no other previous structure defined on it? The authors propose an axiomatization of Einstein-Weyl causality (inspired by physics), and investigate the topological and uniform structures that it implies. Their final result is that a causal space is densely embedded in one that is locally a differentiable manifold. The mathematical level required of the reader is that of the graduate student in mathematical physics. (orig.)

Causality violation, gravitational shockwaves and UV completion

Energy Technology Data Exchange (ETDEWEB)

Hollowood, Timothy J.; Shore, Graham M. [Department of Physics, Swansea University,Swansea, SA2 8PP (United Kingdom)

2016-03-18

The effective actions describing the low-energy dynamics of QFTs involving gravity generically exhibit causality violations. These may take the form of superluminal propagation or Shapiro time advances and allow the construction of “time machines”, i.e. spacetimes admitting closed non-spacelike curves. Here, we discuss critically whether such causality violations may be used as a criterion to identify unphysical effective actions or whether, and how, causality problems may be resolved by embedding the action in a fundamental, UV complete QFT. We study in detail the case of photon scattering in an Aichelburg-Sexl gravitational shockwave background and calculate the phase shifts in QED for all energies, demonstrating their smooth interpolation from the causality-violating effective action values at low-energy to their manifestly causal high-energy limits. At low energies, these phase shifts may be interpreted as backwards-in-time coordinate jumps as the photon encounters the shock wavefront, and we illustrate how the resulting causality problems emerge and are resolved in a two-shockwave time machine scenario. The implications of our results for ultra-high (Planck) energy scattering, in which graviton exchange is modelled by the shockwave background, are highlighted.

Introductive remarks on causal inference

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Silvana A. Romio

2013-05-01

Full Text Available One of the more challenging issues in epidemiological research is being able to provide an unbiased estimate of the causal exposure-disease effect, to assess the possible etiological mechanisms and the implication for public health. A major source of bias is confounding, which can spuriously create or mask the causal relationship. In the last ten years, methodological research has been developed to better de_ne the concept of causation in epidemiology and some important achievements have resulted in new statistical models. In this review, we aim to show how a technique the well known by statisticians, i.e. standardization, can be seen as a method to estimate causal e_ects, equivalent under certain conditions to the inverse probability treatment weight procedure.

Líquens da reserva biológica do Alto da Serra de Paranapiacaba

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Wilson Roberto Pereira

1989-01-01

Full Text Available Com o objetivo principal de levantamento florístico foi efetuado estudo de material depositado no herbário do Instituto de Botânica de São Paulo mais coletas dos autores no ano de 1988. Foram encontradas ao todo 63 espécies, sendo que a maior parte do material antigo não foi recoletado e a amostragem atual revela uma flora heliófila composta principalmente por Parmeliaceae. Lobariaceae presentes nas coletas antigas não puderam ser encontradas, sendo notada também a ausência de liquens fruticosos como Usnea e Ramalina. A alteração da mata por poluição do ar proveniente de Cubatão aliada às condições de excessiva umidade e sombra podem ser os fatores responsáveis pela pobreza da flora liquênica encontrada.The biological reserve of the Serra de Paranapiacaba is part of the Serra do Mar at Santo André city, São Paulo state, Brazil (23º4TS, 46º19'W, 800m above sea level. It is covered with a tropical rain forest and is the most rainy place of Brazil. It stands near (16km of Cubatão city (at sea level from were receives a great deal of air pollutants. The principal aim of this work is verify the old and recent lichen floras of the reserve. Altogether 63 species were found. The most (16 of the 25 species held at the SP herbarium (Instituto de Botânica de São Paulo could not be collected in 1988 and nowadays 60% of the lichens are Parmelia s.l. species. No Stictaceae or corticolous fruticose species, wliich are present at the herbarium, could be recollected in 1988. Air pollution, too high umidity and shade can together be the responsible for the flora poorness.

A Causal Inference Model Explains Perception of the McGurk Effect and Other Incongruent Audiovisual Speech.

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John F Magnotti

2017-02-01

Full Text Available Audiovisual speech integration combines information from auditory speech (talker's voice and visual speech (talker's mouth movements to improve perceptual accuracy. However, if the auditory and visual speech emanate from different talkers, integration decreases accuracy. Therefore, a key step in audiovisual speech perception is deciding whether auditory and visual speech have the same source, a process known as causal inference. A well-known illusion, the McGurk Effect, consists of incongruent audiovisual syllables, such as auditory "ba" + visual "ga" (AbaVga, that are integrated to produce a fused percept ("da". This illusion raises two fundamental questions: first, given the incongruence between the auditory and visual syllables in the McGurk stimulus, why are they integrated; and second, why does the McGurk effect not occur for other, very similar syllables (e.g., AgaVba. We describe a simplified model of causal inference in multisensory speech perception (CIMS that predicts the perception of arbitrary combinations of auditory and visual speech. We applied this model to behavioral data collected from 60 subjects perceiving both McGurk and non-McGurk incongruent speech stimuli. The CIMS model successfully predicted both the audiovisual integration observed for McGurk stimuli and the lack of integration observed for non-McGurk stimuli. An identical model without causal inference failed to accurately predict perception for either form of incongruent speech. The CIMS model uses causal inference to provide a computational framework for studying how the brain performs one of its most important tasks, integrating auditory and visual speech cues to allow us to communicate with others.

Quasi-Experimental Designs for Causal Inference

Science.gov (United States)

Kim, Yongnam; Steiner, Peter

2016-01-01

When randomized experiments are infeasible, quasi-experimental designs can be exploited to evaluate causal treatment effects. The strongest quasi-experimental designs for causal inference are regression discontinuity designs, instrumental variable designs, matching and propensity score designs, and comparative interrupted time series designs. This…

Gravity and matter in causal set theory

International Nuclear Information System (INIS)

Sverdlov, Roman; Bombelli, Luca

2009-01-01

The goal of this paper is to propose an approach to the formulation of dynamics for causal sets and coupled matter fields. We start from the continuum version of the action for a Klein-Gordon field coupled to gravity, and rewrite it first using quantities that have a direct correspondent in the case of a causal set, namely volumes, causal relations and timelike lengths, as variables to describe the geometry. In this step, the local Lagrangian density L(f;x) for a set of fields f is recast into a quasilocal expression L 0 (f;p,q) that depends on pairs of causally related points pprq and is a function of the values of f in the Alexandrov set defined by those points, and whose limit as p and q approach a common point x is L(f;x). We then describe how to discretize L 0 (f;p,q) and use it to define a causal-set-based action.

Avaliação da diversidade genética e associação com patogenicidade de isolados de Moniliophthora perniciosa oriundos da Amazônia Brasileira

OpenAIRE

Angela Sanche Artero Freitas

2012-01-01

O fungo Moniliophthora perniciosa é o agente causal da vassoura de bruxa no cacaueiro (Theobroma cacao L.). Três biótipos distintos (biótipos -C, -L e -S) são reconhecidos de acordo com a especificidade quanto ao hospedeiro. O presente estudo teve como objetivo a análise da diversidade genética com o uso de marcadores microssatélites de 134 isolados dos biótipos -C, -L e -S de M. perniciosa coletados principalmente na Amazônia Brasileira e áreas de cultivo. A diversidade genética foi associad...

Causal theory in (2+1)-dimensional Qed

International Nuclear Information System (INIS)

Scharf, G.; Wreszinski, W.F.

1994-01-01

The program of constructing the S-matrix by means of causality in quantum field theory goes back to Stueckelberg and Bogoliubov. Epstein and Glaser proposed an axiomatic construct where ultraviolet divergences do not appear, leading directly to the renormalized perturbation series. They have shown that in the causal theory the UV problem is a consequence of incorrect distribution splitting. This paper studies the causal theory in (2+1)D Qed

How multiple causes combine: independence constraints on causal inference.

Science.gov (United States)

Liljeholm, Mimi

2015-01-01

According to the causal power view, two core constraints-that causes occur independently (i.e., no confounding) and influence their effects independently-serve as boundary conditions for causal induction. This study investigated how violations of these constraints modulate uncertainty about the existence and strength of a causal relationship. Participants were presented with pairs of candidate causes that were either confounded or not, and that either interacted or exerted their influences independently. Consistent with the causal power view, uncertainty about the existence and strength of causal relationships was greater when causes were confounded or interacted than when unconfounded and acting independently. An elemental Bayesian causal model captured differences in uncertainty due to confounding but not those due to an interaction. Implications of distinct sources of uncertainty for the selection of contingency information and causal generalization are discussed.

The mistake of the causal relationship

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О. Д. Комаров

2015-03-01

Full Text Available The article deals with issues of the mistake of the causal relationship. The modern criminal law science approaches to the content of the mistake of the causal relationship and its significance to the qualification of the crime are described. It is proved that in cases of dolus generalis different mental attitude of the guilty person to two separate acts of his conduct exist. Consequently, in mentioned above cases mistake of the causal relationship does not have place. The rules of qualification of the crimes commited with the mistake of causation and in cases of dolus generalis are proposed .

Causal independence between energy consumption and economic growth in Liberia: Evidence from a non-parametric bootstrapped causality test

International Nuclear Information System (INIS)

Wesseh, Presley K.; Zoumara, Babette

2012-01-01

This contribution investigates causal interdependence between energy consumption and economic growth in Liberia and proposes application of a bootstrap methodology. To better reflect causality, employment is incorporated as additional variable. The study demonstrates evidence of distinct bidirectional Granger causality between energy consumption and economic growth. Additionally, the results show that employment in Liberia Granger causes economic growth and apply irrespective of the short-run or long-run. Evidence from a Monte Carlo experiment reveals that the asymptotic Granger causality test suffers size distortion problem for Liberian data, suggesting that the bootstrap technique employed in this study is more appropriate. Given the empirical results, implications are that energy expansion policies like energy subsidy or low energy tariff for instance, would be necessary to cope with demand exerted as a result of economic growth in Liberia. Furthermore, Liberia might have the performance of its employment generation on the economy partly determined by adequate energy. Therefore, it seems fully justified that a quick shift towards energy production based on clean energy sources may significantly slow down economic growth in Liberia. Hence, the government’s target to implement a long-term strategy to make Liberia a carbon neutral country, and eventually less carbon dependent by 2050 is understandable. - Highlights: ► Causality between energy consumption and economic growth in Liberia investigated. ► There is bidirectional causality between energy consumption and economic growth. ► Energy expansion policies are necessary to cope with demand from economic growth. ► Asymptotic Granger causality test suffers size distortion problem for Liberian data. ► The bootstrap methodology employed in our study is more appropriate.

CONTROLE QUÍMICO DOS PULG��ES Mysus persicae E Brevicoryne brassicae NA CULTURA DA COUVE-FLOR COM INSETICIDAS APLICADOS NA FORMA DE ESGUICHO CHEMICAL CONTROL OF APHIDS Mizus persicae AND Brevicoryne brassicae ON CAULIFLOWER WITH INSECTICIDES APPLIED IN TRANSPLANT HOLES

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Selby Pereira dos Santos

2007-09-01

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Avaliou-se o controle químico dos pulgões Mysus persicae e Brevicoryne brassicae, em couve-flor, através dos inseticidas Confidor 700 GRDA e Confidor 200 SC, na área experimental da Escola de Agronomia da Universidade Federal de Goiás em maio de 1998. Foram utilizadas duas dosagens para cada um dos inseticidas, um inseticida padrão (Tamaron Br e uma testemunha. Confidor 700 GRDA e Confidor 200 SC, ambos em duas dosagens, foram aplicados em uma única vez nas covas de transplante, com um pulverizador costal, utilizando bico de esguicho. A avaliação dos resultados de M. persicae constou de contagens de ninfas e adultos em folhas escolhidas ao acaso, nas plantas da linha central das parcelas, 35 dias após os tratamentos. A mesma metodologia foi utilizada para a avaliação de B. brassicae 48 dias após o tratamento. O tratamento com Tamaron Br foi aplicado na forma de pulverizações semanais, ocorrendo as avalia

Análisis de la evolución diacrónica (1984-2014 de los fresnales de flor (Fraxinus ornus L. valencianos mediante la interpretación de su interactividad geoecológica (“Método EFG-Meaza”

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David Cristel Gómez-Montblanch, Pedro José Lozano-Valencia, Emilio Laguna-Lumbreras, Pedro Pablo Ferrer-Gallego, Guillermo Meaza-Rodrïguez

2016-01-01

Full Text Available En el presente trabajo se aborda el análisis de la influencia que ejercen los factores mesológicos –agrupados según la metodología propuesta (“Método EFG-Meaza”- para cada etapa de la sucesión vegetal en una comunidad de fresno de flor (Fraxinus ornus L. de la Sierra de Malacara (Buñol, Valencia estudiada por Laguna et al. (2015b mediante su aplicación con carácter diacrónico (1984-2014. Se pretende comprobar si el grado de complejidad de las relaciones ecológicas estudiadas a la escala territorial propuesta –interactividad geoecológica- guarda relación con la evolución de la comunidad concernida en cada etapa de sucesión, prestando especial atención a los cambios en su estructura y composición florística.

A Bayesian Theory of Sequential Causal Learning and Abstract Transfer.

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

2016-03-01

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 abstract causal constraints? Recent empirical studies have revealed that experience with one set of causal cues can dramatically alter subsequent learning and performance with entirely different cues, suggesting that learning involves abstract transfer, and such transfer effects involve sequential presentation of distinct sets of causal cues. It has been demonstrated that pre-training (or even post-training) can modulate classic causal learning phenomena such as forward and backward blocking. To account for these effects, we propose a Bayesian theory of sequential causal learning. The theory assumes that humans are able to consider and use several alternative causal generative models, each instantiating a different causal integration rule. Model selection is used to decide which integration rule to use in a given learning environment in order to infer causal knowledge from sequential data. Detailed computer simulations demonstrate that humans rely on the abstract characteristics of outcome variables (e.g., binary vs. continuous) to select a causal integration rule, which in turn alters causal learning in a variety of blocking and overshadowing paradigms. When the nature of the outcome variable is ambiguous, humans select the model that yields the best fit with the recent environment, and then apply it to subsequent learning tasks. Based on sequential patterns of cue-outcome co-occurrence, the theory can account for a range of phenomena in sequential causal learning, including various blocking effects, primacy effects in some experimental conditions, and apparently abstract transfer of causal knowledge. Copyright © 2015

On minimizers of causal variational principles

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Schiefeneder, Daniela

2011-01-01

Causal variational principles are a class of nonlinear minimization problems which arise in a formulation of relativistic quantum theory referred to as the fermionic projector approach. This thesis is devoted to a numerical and analytic study of the minimizers of a general class of causal variational principles. We begin with a numerical investigation of variational principles for the fermionic projector in discrete space-time. It is shown that for sufficiently many space-time points, the minimizing fermionic projector induces non-trivial causal relations on the space-time points. We then generalize the setting by introducing a class of causal variational principles for measures on a compact manifold. In our main result we prove under general assumptions that the support of a minimizing measure is either completely timelike, or it is singular in the sense that its interior is empty. In the examples of the circle, the sphere and certain flag manifolds, the general results are supplemented by a more detailed analysis of the minimizers. (orig.)

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...

Estructura y composición florística de tres robledales en la región norte de la cordillera central de Colombia

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Juan D León

2009-12-01

Full Text Available La alta diversidad florística que albergan los ecosistemas andinos está siendo amenazada por fuertes presiones de origen antrópico. Uno de estos ecosistemas son los robledales, bosques dominados por la especie Quercus humboldtii, que se encuentra seriamente amenazada en Colombia porque su madera es valiosa comercial y dendroenergéticamente. En este estudio, se caracterizó la composición florística y la estructura de tres robledales de los Andes colombianos, con el fin de determinar su similaridad. En cada sitio, se estableció una parcela permanente (5 000 m² donde se muestrearon todos los árboles con D ≥ 10 cm. En los tres sitios, la especie dominante fue Q. humboldtii, pero la similitud florística entre ellos no fue alta. La estructura por clases de tamaño para los tres sitios fue en forma de J invertida, aunque varió la abundancia de individuos por clase diamétrica. Los resultados indican que los robledales estudiados difieren en su composición florística y estructura a pesar de presentar características biofísicas similares. Las diferencias encontradas se deben posiblemente, a los diferentes factores que interactúan en cada sitio como la historia de uso, intensidad y duración de las perturbaciones antrópicas pasadas, topografía, fauna y clima local, que se ven reflejados en los parámetros estructurales de la vegetación.Structure and floristic composition of three oak forests in the northern region of the Central Cordillera in Colombia. Andean ecosystems harbor a high floristic diversity, which is being threatened by human disturbances such us deforestation and by the expansion of the agricultural frontier. One of these ecosystems are the Andean oak forests dominated by Quercus humboldtii, a threatened species in Colombia. We assessed the floristic composition and structure of three Andean oak forests located in three localities (San Andrés de Cuerquia, Belmira and Guarne of Antioquia. The main goal was to determine

Causal inference in biology networks with integrated belief propagation.

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Chang, Rui; Karr, Jonathan R; Schadt, Eric E

2015-01-01

Inferring causal relationships among molecular and higher order phenotypes is a critical step in elucidating the complexity of living systems. Here we propose a novel method for inferring causality that is no longer constrained by the conditional dependency arguments that limit the ability of statistical causal inference methods to resolve causal relationships within sets of graphical models that are Markov equivalent. Our method utilizes Bayesian belief propagation to infer the responses of perturbation events on molecular traits given a hypothesized graph structure. A distance measure between the inferred response distribution and the observed data is defined to assess the 'fitness' of the hypothesized causal relationships. To test our algorithm, we infer causal relationships within equivalence classes of gene networks in which the form of the functional interactions that are possible are assumed to be nonlinear, given synthetic microarray and RNA sequencing data. We also apply our method to infer causality in real metabolic network with v-structure and feedback loop. We show that our method can recapitulate the causal structure and recover the feedback loop only from steady-state data which conventional method cannot.

Efeito de queimadas sobre a estrutura e composição da comunidade vegetal lenhosa do cerrado sentido restrito em Caldas Novas, GO Effect of fire on the structure and floristic composition of a cerrado sensu stricto area in Caldas Novas, GO

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Sérgio de Faria Lopes

2009-08-01

Full Text Available Considerando que o regime de queima é um dos principais fatores que alteram a estrutura e composição de espécies de uma comunidade vegetal, este trabalho teve como objetivo analisar o efeito do fogo na composição florística e estrutura da vegetação lenhosa de Cerrado sentido restrito no Parque Estadual da Serra de Caldas Novas (PESCAN, Goiás, submetida a diferentes regimes de queima. Foram utilizadas duas áreas de Cerrado sentido restrito: uma delas submetida ao fogo em 2002 e 2006 e outra sem a passagem do fogo nessas duas épocas. Em cada área foram estabelecidas 25 parcelas de 20 x 20 m, sendo incluídas no estudo todas as árvores (C30>15 cm. As duas áreas estudadas apresentaram composição florística similar, evidenciada pelo Coeficiente de Sorensen, o qual encontrou 84% de similaridade na composição florística entre as áreas. Entretanto, a estrutura da vegetação apresentou diferenças relevantes, evidenciada pelo Indice de Similaridade de Bray Curtis, o qual obteve valor de 0,67, que foi refletido por mudanças na estrutura das comunidades estudadas. A área queimada apresentou menor número de indivíduos, de espécies, menor valor de área basal e, por conseguinte, do Índice de Diversidade de Shannon (H' e Equabilidade (J'. Nesse sentido, provavelmente a frequência das queimadas ocorridas na área não foram suficientes para evidenciar o efeito do fogo no processo de alteração na composição das espécies lenhosas. Entretanto, o fogo exerceu papel relevante na modificação da estrutura da vegetação.Considering that the regimes of burning modify important factors of the structure and composition of the species of a plant community, the objective of this work was to analyze the effect of burning on the floristic composition and structure of the wood vegetation of the cerrado sensu stricto at the Parque Estadual da Serra de Caldas Novas (PESCAN, Goiás, submitted to different times of burning. Two areas had been

A general, multivariate definition of causal effects in epidemiology.

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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.

Information causality from an entropic and a probabilistic perspective

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Al-Safi, Sabri W.; Short, Anthony J.

2011-01-01

The information causality principle is a generalization of the no-signaling principle which implies some of the known restrictions on quantum correlations. But despite its clear physical motivation, information causality is formulated in terms of a rather specialized game and figure of merit. We explore different perspectives on information causality, discussing the probability of success as the figure of merit, a relation between information causality and the nonlocal ''inner-product game,'' and the derivation of a quadratic bound for these games. We then examine an entropic formulation of information causality with which one can obtain the same results, arguably in a simpler fashion.

Causal Mediation Analysis: Warning! Assumptions Ahead

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Keele, Luke

2015-01-01

In policy evaluations, interest may focus on why a particular treatment works. One tool for understanding why treatments work is causal mediation analysis. In this essay, I focus on the assumptions needed to estimate mediation effects. I show that there is no "gold standard" method for the identification of causal mediation effects. In…

How to Be Causal: Time, Spacetime and Spectra

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Kinsler, Paul

2011-01-01

I explain a simple definition of causality in widespread use, and indicate how it links to the Kramers-Kronig relations. The specification of causality in terms of temporal differential equations then shows us the way to write down dynamical models so that their causal nature "in the sense used here" should be obvious to all. To extend existing…

On the road toward formal reasoning: reasoning with factual causal and contrary-to-fact causal premises during early adolescence.

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Markovits, Henry

2014-12-01

Understanding the development of conditional (if-then) reasoning is critical for theoretical and educational reasons. Here we examined the hypothesis that there is a developmental transition between reasoning with true and contrary-to-fact (CF) causal conditionals. A total of 535 students between 11 and 14 years of age received priming conditions designed to encourage use of either a true or CF alternatives generation strategy and reasoning problems with true causal and CF causal premises (with counterbalanced order). Results show that priming had no effect on reasoning with true causal premises. By contrast, priming with CF alternatives significantly improved logical reasoning with CF premises. Analysis of the effect of order showed that reasoning with CF premises reduced logical responding among younger students but had no effect among older students. Results support the idea that there is a transition in the reasoning processes in this age range associated with the nature of the alternatives generation process required for logical reasoning with true and CF causal conditionals. Copyright © 2014 Elsevier Inc. All rights reserved.

BOLD Granger causality reflects vascular anatomy.

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J Taylor Webb

Full Text Available A number of studies have tried to exploit subtle phase differences in BOLD time series to resolve the order of sequential activation of brain regions, or more generally the ability of signal in one region to predict subsequent signal in another region. More recently, such lag-based measures have been applied to investigate directed functional connectivity, although this application has been controversial. We attempted to use large publicly available datasets (FCON 1000, ADHD 200, Human Connectome Project to determine whether consistent spatial patterns of Granger Causality are observed in typical fMRI data. For BOLD datasets from 1,240 typically developing subjects ages 7-40, we measured Granger causality between time series for every pair of 7,266 spherical ROIs covering the gray matter and 264 seed ROIs at hubs of the brain's functional network architecture. Granger causality estimates were strongly reproducible for connections in a test and replication sample (n=620 subjects for each group, as well as in data from a single subject scanned repeatedly, both during resting and passive video viewing. The same effect was even stronger in high temporal resolution fMRI data from the Human Connectome Project, and was observed independently in data collected during performance of 7 task paradigms. The spatial distribution of Granger causality reflected vascular anatomy with a progression from Granger causality sources, in Circle of Willis arterial inflow distributions, to sinks, near large venous vascular structures such as dural venous sinuses and at the periphery of the brain. Attempts to resolve BOLD phase differences with Granger causality should consider the possibility of reproducible vascular confounds, a problem that is independent of the known regional variability of the hemodynamic response.

The causal structure of utility conditionals.

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Bonnefon, Jean-François; Sloman, Steven A

2013-01-01

The psychology of reasoning is increasingly considering agents' values and preferences, achieving greater integration with judgment and decision making, social cognition, and moral reasoning. Some of this research investigates utility conditionals, ''if p then q'' statements where the realization of p or q or both is valued by some agents. Various approaches to utility conditionals share the assumption that reasoners make inferences from utility conditionals based on the comparison between the utility of p and the expected utility of q. This article introduces a new parameter in this analysis, the underlying causal structure of the conditional. Four experiments showed that causal structure moderated utility-informed conditional reasoning. These inferences were strongly invited when the underlying structure of the conditional was causal, and significantly less so when the underlying structure of the conditional was diagnostic. This asymmetry was only observed for conditionals in which the utility of q was clear, and disappeared when the utility of q was unclear. Thus, an adequate account of utility-informed inferences conditional reasoning requires three components: utility, probability, and causal structure. Copyright © 2012 Cognitive Science Society, Inc.

Entanglement, holography and causal diamonds

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de Boer, Jan; Haehl, Felix M.; Heller, Michal P.; Myers, Robert C.

2016-08-01

We argue that the degrees of freedom in a d-dimensional CFT can be reorganized 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 2 d-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 entanglemententropy from this unifying point of view. We demonstrate that for small perturbations of the vacuum, our observables obey linear two-derivative equations of motion on the space of causal diamonds. In two dimensions, the latter is given by a product of two copies of a two-dimensional de Sitter space. For a class of universal states, we show that the entanglement entropy and its spin-three generalization obey nonlinear equations of motion with local interactions on this moduli space, which can be identified with Liouville and Toda equations, respectively. This suggests the possibility of extending the definition of our new observables beyond the linear level more generally and in such a way that they give rise to new dynamically interacting theories on the moduli space of causal diamonds. Various challenges one has to face in order to implement this idea are discussed.

Entanglement, holography and causal diamonds

Energy Technology Data Exchange (ETDEWEB)

Boer, Jan de [Institute of Physics, Universiteit van Amsterdam,Science Park 904, 1090 GL Amsterdam (Netherlands); Haehl, Felix M. [Centre for Particle Theory & Department of Mathematical Sciences, Durham University,South Road, Durham DH1 3LE (United Kingdom); Heller, Michal P.; Myers, Robert C. [Perimeter Institute for Theoretical Physics,31 Caroline Street North, Waterloo, Ontario N2L 2Y5 (Canada)

2016-08-29

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 vacuum, our observables obey linear two-derivative equations of motion on the space of causal diamonds. In two dimensions, the latter is given by a product of two copies of a two-dimensional de Sitter space. For a class of universal states, we show that the entanglement entropy and its spin-three generalization obey nonlinear equations of motion with local interactions on this moduli space, which can be identified with Liouville and Toda equations, respectively. This suggests the possibility of extending the definition of our new observables beyond the linear level more generally and in such a way that they give rise to new dynamically interacting theories on the moduli space of causal diamonds. Various challenges one has to face in order to implement this idea are discussed.

Detectability of Granger causality for subsampled continuous-time neurophysiological processes.

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Barnett, Lionel; Seth, Anil K

2017-01-01

Granger causality is well established within the neurosciences for inference of directed functional connectivity from neurophysiological data. These data usually consist of time series which subsample a continuous-time biophysiological process. While it is well known that subsampling can lead to imputation of spurious causal connections where none exist, less is known about the effects of subsampling on the ability to reliably detect causal connections which do exist. We present a theoretical analysis of the effects of subsampling on Granger-causal inference. Neurophysiological processes typically feature signal propagation delays on multiple time scales; accordingly, we base our analysis on a distributed-lag, continuous-time stochastic model, and consider Granger causality in continuous time at finite prediction horizons. Via exact analytical solutions, we identify relationships among sampling frequency, underlying causal time scales and detectability of causalities. We reveal complex interactions between the time scale(s) of neural signal propagation and sampling frequency. We demonstrate that detectability decays exponentially as the sample time interval increases beyond causal delay times, identify detectability "black spots" and "sweet spots", and show that downsampling may potentially improve detectability. We also demonstrate that the invariance of Granger causality under causal, invertible filtering fails at finite prediction horizons, with particular implications for inference of Granger causality from fMRI data. Our analysis emphasises that sampling rates for causal analysis of neurophysiological time series should be informed by domain-specific time scales, and that state-space modelling should be preferred to purely autoregressive modelling. On the basis of a very general model that captures the structure of neurophysiological processes, we are able to help identify confounds, and offer practical insights, for successful detection of causal connectivity

Dual Causality and the Autonomy of Biology.

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Bock, Walter J

2017-03-01

Ernst Mayr's concept of dual causality in biology with the two forms of causes (proximate and ultimate) continues to provide an essential foundation for the philosophy of biology. They are equivalent to functional (=proximate) and evolutionary (=ultimate) causes with both required for full biological explanations. The natural sciences can be classified into nomological, historical nomological and historical dual causality, the last including only biology. Because evolutionary causality is unique to biology and must be included for all complete biological explanations, biology is autonomous from the physical sciences.

Can chance cause cancer? A causal consideration.

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Stensrud, Mats Julius; Strohmaier, Susanne; Valberg, Morten; Aalen, Odd Olai

2017-04-01

The role of randomness, environment and genetics in cancer development is debated. We approach the discussion by using the potential outcomes framework for causal inference. By briefly considering the underlying assumptions, we suggest that the antagonising views arise due to estimation of substantially different causal effects. These effects may be hard to interpret, and the results cannot be immediately compared. Indeed, it is not clear whether it is possible to define a causal effect of chance at all. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determining Directional Dependency in Causal Associations

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Pornprasertmanit, Sunthud; Little, Todd D.

2012-01-01

Directional dependency is a method to determine the likely causal direction of effect between two variables. This article aims to critique and improve upon the use of directional dependency as a technique to infer causal associations. We comment on several issues raised by von Eye and DeShon (2012), including: encouraging the use of the signs of…

Abiotic gradients drive floristic composition and structure of plant communities in the Monte Desert Gradientes abióticos dirigen la composición florística y la estructura de las comunidades de plantas en el Desierto del Monte

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PABLO ACEBES

2010-01-01

Full Text Available Defining plant communities in desert zones is difficult due to large scale homogeneity and small scale heterogeneity, thus making provision of systematic information for conservation decisions problematic. We analysed plant communities of the most arid sector of Monte Desert for structure, plant composition and environmental variables. Small-scale variables such as slope, rock cover, bare ground and litter, as well as large-scale ones such as species diversity, composition and similarity within and between sites were included. Analyses of floristic composition showed the difficulty of segregating distinct communities due to high internal heterogeneity and overlap between the different sites. Only mesquite woodlands, a community situated at the extreme of the soil moisture-gradient was segregated. Ordination on structural variables was somewhat more successful in segregating communities on the basis of substrate type and of tree and shrub cover. Our results showed the difficulty distinguishing plant communities in temperate deserts, suggesting the existence of relatively stable assemblages of species at the extremes of the gradients and of great heterogeneity within and between sites. They cannot be defined by floristic variables solely, but require environmental information also.La definición de comunidades discretas de plantas en zonas desérticas es complejo debido tanto a su homogeneidad a gran escala como a su heterogeneidad a pequeña escala, lo que acaba generando dificultades para la toma de decisiones de conservación. En este trabajo analizamos las comunidades de plantas del sector más árido del Desierto del Monte en función de su estructura y composición florística. Se han utilizado también variables ambientales estimadas a pequeña escala como la pendiente o la superficie de roca, suelo desnudo y hojarasca, así como variables que operan a mayor escala como la diversidad de especies, la composición florística y la similitud

Estrutura de uma floresta tropical dez anos após exploração de madeira em Moju, Pará

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Fernando Cristóvam da Silva Jardim

Full Text Available RESUMO Estudos das dinâmicas florística e estrutural em áreas de exploração florestal permitem avaliar os impactos e fornecem informações básicas para o manejo florestal racional. Nesse contexto, as dinâmicas florística e estrutural foram avaliadas em uma floresta tropical, dez anos após sua exploração madeireira. O experimento foi executado em 200 ha do Campo Experimental da Embrapa Amazônia Oriental, em Moju, PA, onde foi feita a exploração madeireira. No entorno de nove clareiras selecionadas foram instaladas faixas de 10 m x 50 m, divididas em parcelas quadradas de 10 m de lado (1 a 5, onde foram inventariadas as plantas com DAP ≥ 5 cm. Nas parcelas 1, 3 e 5 e no centro da clareira foram instaladas subparcelas de 2 m x 2 m, onde foram medidos os indivíduos com altura ≥ 10 cm e DAP < 5 cm. O monitoramento da floresta abrangeu um período de nove anos e meio, entre março de 1998 e outubro de 2007. A análise estrutural foi feita com base nos parâmetros de abundância, frequência, dominância, regeneração natural, posição sociológica e índice de valor de importância ampliado (IVIA, sendo comparadas as estruturas da floresta dos anos de 2007 e 1998. Dez anos após a exploração, a alta heterogeneidade foi mantida e aumentou no povoamento mais jovem, graças ao ingresso de espécies com forte demanda por luz. Entretanto, a composição florística e a estrutura da floresta manejada ainda mostram grande importância de espécies que, em florestas não perturbadas, não teriam grande expressão em termos de IVIA.

Causal strength induction from time series data.

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Soo, Kevin W; Rottman, Benjamin M

2018-04-01

One challenge when inferring the strength of cause-effect relations from time series data is that the cause and/or effect can exhibit temporal trends. If temporal trends are not accounted for, a learner could infer that a causal relation exists when it does not, or even infer that there is a positive causal relation when the relation is negative, or vice versa. We propose that learners use a simple heuristic to control for temporal trends-that they focus not on the states of the cause and effect at a given instant, but on how the cause and effect change from one observation to the next, which we call transitions. Six experiments were conducted to understand how people infer causal strength from time series data. We found that participants indeed use transitions in addition to states, which helps them to reach more accurate causal judgments (Experiments 1A and 1B). Participants use transitions more when the stimuli are presented in a naturalistic visual format than a numerical format (Experiment 2), and the effect of transitions is not driven by primacy or recency effects (Experiment 3). Finally, we found that participants primarily use the direction in which variables change rather than the magnitude of the change for estimating causal strength (Experiments 4 and 5). Collectively, these studies provide evidence that people often use a simple yet effective heuristic for inferring causal strength from time series data. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Dimensões lineares da folha e seu uso na determinação do perfil vertical foliar de gladíolo

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Natalia Teixeira Schwab

2014-06-01

Full Text Available O gladíolo, importante flor de corte, é uma planta herbácea e suas folhas apresentam formato de lança. Os objetivos do trabalho foram determinar um modelo matemático empírico que melhor estima a área da folha do gladíolo a partir de dimensões lineares e aplicar o modelo matemático para determinar o perfil vertical da área das folhas de diferentes posições na planta. Para isso foi realizado um experimento de campo em Santa Maria com quatro cultivares de gladíolo (Peter Pears, Rose Friendship, Jester e Amsterdã, sendo coletadas 50 folhas de cada cultivar, das quais mensuraram-se o comprimento (C e a maior largura (L. Em seguida, fotocopiou-se cada folha em um scanner, calculando-se a área individual (AF com auxílio de um software. A relação entre área e as dimensões das folhas foi ajustada no modelo potência e a capacidade preditiva das equações foi avaliada por várias estatísticas. Resultados indicam que o modelo AF = a (C.L é o mais indicado para a estimativa da área foliar em gladíolo, podendo-se utilizar a = 0,644 para as quatro cultivares testadas. As menores folhas estão nas posições basais e apicais e as maiores, na posição intermediária da planta.

Composição florística e fitossociologia de espécies arbóreas do Parque Fenológico da Embrapa Amazônia Ocidental Floristic composition and phytosociology of tree species in the Phenological Site of the Embrapa Western Amazonia

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Kátia Emídio da Silva

2008-01-01

Full Text Available Este trabalho objetiva avaliar a composição florística e a fitossociologia de espécies arbóreas do parque fenológico da Embrapa Amazônia Ocidental no Distrito Agropecuário da Suframa (DAS, Manaus-AM, a fim de subsidiar seleções futuras de árvores matrizes visando estudos fenológicos e a implantação de áreas de coleta de sementes. Foram alocadas aleatoriamente 20 parcelas de 10m x 50 m ao longo de um transecto, amostrando-se todos os indivíduos com diâmetro a 1,30 m do solo, (DAP ≥ 20,0 cm. Foram registrados 240 indivíduos, distribuídos em 100 espécies, 70 gêneros e 29 famílias. As famílias de maior importância ecológica são, em ordem decrescente, Lecythidaceae, Sapotaceae, Mimosaceae, Caesalpiniaceae, Chrysobalanaceae, Fabaceae, Humiriaceae, Moraceae, Vochysiaceae e Apocynaceae. Essas famílias contribuem com 67% da riqueza local de espécies e com 75,8% do número de indivíduos, sugerindo que a diversidade vegetal da área está concentrada em poucas famílias. A família Lecythidaceae possui os maiores valores de dap e número de indivíduos, sendo Sapotaceae a que possui a maior riqueza de espécies na área. As espécies mais importantes, segundo o Índice de Valor de Importância-IVI, são Eschweilera coriacea (DC S.A. Mori; Qualea paraensis Ducke; Vantanea macrocarpa Ducke; Eschweilera atropetiolataThis research was carried out to study the floristic composition and phytosociology of tree species in the phenological site of Embrapa Western Amazonia, Suframa Agropecuary District-SAD, Manaus-AM, aiming to help future selection of seed trees, for the establishment of seed collecting areas. Twenty plots of 10m x 50m were studied, along a topographic sequence, where trees with a diameter at breast height (dbh ≥ 20,0cm were inventoried. A total of 240 trees belonging to 29 families, in 70 genera with 100 species were identified. The most important families, in a decreasing order, were: Lecythidaceae, Sapotaceae

The Relevance of Causal Social Construction

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Marques Teresa

2017-02-01

Full Text Available Social constructionist claims are surprising and interesting when they entail that presumably natural kinds are in fact socially constructed. The claims are interesting because of their theoretical and political importance. Authors like Díaz-León argue that constitutive social construction is more relevant for achieving social justice than causal social construction. This paper challenges this claim. Assuming there are socially salient groups that are discriminated against, the paper presents a dilemma: if there were no constitutively constructed social kinds, the causes of the discrimination of existing social groups would have to be addressed, and understanding causal social construction would be relevant to achieve social justice. On the other hand, not all possible constitutively socially constructed kinds are actual social kinds. If an existing social group is constitutively constructed as a social kind K, the fact that it actually exists as a K has social causes. Again, causal social construction is relevant. The paper argues that (i for any actual social kind X, if X is constitutively socially constructed as K, then it is also causally socially constructed; and (ii causal social construction is at least as relevant as constitutive social construction for concerns of social justice. For illustration, I draw upon two phenomena that are presumed to contribute towards the discrimination of women: (i the poor performance effects of stereotype threat, and (ii the silencing effects of gendered language use.

Selecting appropriate cases when tracing causal mechanisms

DEFF Research Database (Denmark)

Beach, Derek; Pedersen, Rasmus Brun

2016-01-01

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 unpack the causal mechanism between X and Y, enabling causal inferences to be made because empirical evidence is provided for how the mechanism actually operated in a particular case. The in-depth, within-case tracing of how mechanisms operate in particular cases produces what can be termed mechanistic...

Explaining quantum correlations through evolution of causal models

Science.gov (United States)

Harper, Robin; Chapman, Robert J.; Ferrie, Christopher; Granade, Christopher; Kueng, Richard; Naoumenko, Daniel; Flammia, Steven T.; Peruzzo, Alberto

2017-04-01

We propose a framework for the systematic and quantitative generalization of Bell's theorem using causal networks. We first consider the multiobjective optimization problem of matching observed data while minimizing the causal effect of nonlocal variables and prove an inequality for the optimal region that both strengthens and generalizes Bell's theorem. To solve the optimization problem (rather than simply bound it), we develop a genetic algorithm treating as individuals causal networks. By applying our algorithm to a photonic Bell experiment, we demonstrate the trade-off between the quantitative relaxation of one or more local causality assumptions and the ability of data to match quantum correlations.

Tachyon kinematics and causality: a systematic thorough analysis of the tachyon causal paradoxes

International Nuclear Information System (INIS)

Recami, E.

1987-01-01

The chronological order of the events along a spacelike path is not invariant under Lorentz transformations, as is well known. This led to an early conviction that tachyons would give rise to causal anomalies. A relativistic version of the Stueckelberg-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 detector. 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 the tachyon relativistic mechanics has been properly developed. They start by showing how to apply the SWP, both in the case of ordinary special relativity and in the case with tachyons. Then they carefully exploit the kinetics of the tachyon exchange between two (ordinary) bodies. Being finally able to tackle the tachyon causality problem, they successively solve the paradoxes of: (i) Tolman-Regge, (ii) Pirani, (iii) Edmonds, and (iv) Bell. Finally, they discuss a further, new paradox associated with the transmission of signals by modulated tachyon beams

Powdery mildew of ornamental species caused by Oidiopsis haplophylli in Brazil Oídio em plantas ornamentais, causado por Oidiopsis haplophylli, no Brasil

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Ailton Reis

2007-12-01

: Gentianaceae e flor-borboleta (Asclepias physocarpa: Asclepiadaceae em Brasília-DF, Brasil. Esta doença foi observada em condições de casa de vegetação em beijo-de-frade, copo-de-leite, lisianthus e flor-borboleta e em condições de campo na capuchinha. O sintoma típico é o aparecimento de uma área clorótica na superfície superior da lâmina foliar que corresponde a uma colônia fúngica na superfície inferior. Com o progresso da doença, estas lesões tornavam-se necróticas e eventualmente coalesciam. As características morfológicas, observadas em microscopia de luz, corresponderam àquelas descritas para a fase imperfeita do fungo Leveillula taurica (O. haplophylli. Os testes de patogenicidade foram completados via inoculação por contato entre folhas sadias e folhas apresentado colônias do fungo. Um isolado de pimentão foi também patogênico a estas cinco espécies ornamentais (pertencentes a diferentes famílias botânicas confirmando a ausência de especialização por hospedeiro deste fungo. Este é o primeiro registro deste patógeno nestas espécies ornamentais no Brasil e, provavelmente, o primeiro relato de flor-borboleta como hospedeira. Este oídio pode se tornar importante para o cultivo destas espécies em cultivo protegido ou condições de clima quente e seco.

Composição, diversidade e similaridade florística de uma floresta tropical semidecídua submontana em Marcelândia - MT Floristic composition, diversity and similarity of a submontane semideciduous tropical forest in Marcelândia - MT

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Elbert Viana Ferreira Júnior

2008-12-01

Full Text Available O objetivo deste estudo foi avaliar a composição, diversidade e similaridade florística de uma área de floresta estacional semidecidual localizada no município de Marcelândia-MT, em área de tensão ecológica, na região de contato floresta ombrófila/floresta estacional. Foram amostrados 4008 indivíduos, pertencentes a 33 famílias e 92 espécies, em 74 parcelas de 10 m x 250 m. As famílias que apresentaram maior valor percentual de árvores foram: Lauraceae (15,99%, Melastomataceae (12,97%, Sapotaceae (12,50%, Fabaceae - Mimosoideae (9,91%, Burseraceae (9,13% e Moraceae (7,29%. Os valores obtidos para os índices de diversidade Shannon-Weaver, de concentração de Simpson e de equitabilidade de Pielou indicaram que a área apresenta diversidade relativamente alta e baixa concentração de espécies com alta uniformidade nas proporções indivíduos/espécies dentro da comunidade vegetal. Os padrões de similaridade florística evidenciaram baixa similaridade entre as áreas avaliadas evidenciando existência de padrões fitogeográficos baseados na distribuição das espécies.The objective of this study was to analyze the floristic composition, diversity and similarity of a submontane, semideciduous tropical forest in Marcelândia-MT, in an ecological tension area in the forest contact region. The 33 families and 92 species specimens were found in 4008 individuals, in 74 plots of 10m x 250 m. The families that contributed most frequently to the floristic composition were Lauraceae (15.99%, Melastomataceae (12.97%, Sapotaceae (12.50%, Fabaceae - Mimosoideae (9.91%, Burseraceae (9.13% and Moraceae (7.29%. The Shannon-Weaver diversity, Simpson concentration and Pielou evenness indexes indicated that the area presents relatively high diversity and low concentration of species with high uniformity in the ratios of individuals per species. The floristic similarity standards had low similarity among the evaluated areas evidencing the

Causal learning and inference as a rational process: the new synthesis.

Science.gov (United States)

Holyoak, Keith J; Cheng, Patricia W

2011-01-01

Over the past decade, an active line of research within the field of human causal learning and inference has converged on a general representational framework: causal models integrated with bayesian probabilistic inference. We describe this new synthesis, which views causal learning and inference as a fundamentally rational process, and review a sample of the empirical findings that support the causal framework over associative alternatives. Causal events, like all events in the distal world as opposed to our proximal perceptual input, are inherently unobservable. A central assumption of the causal approach is that humans (and potentially nonhuman animals) have been designed in such a way as to infer the most invariant causal relations for achieving their goals based on observed events. In contrast, the associative approach assumes that learners only acquire associations among important observed events, omitting the representation of the distal relations. By incorporating bayesian inference over distributions of causal strength and causal structures, along with noisy-logical (i.e., causal) functions for integrating the influences of multiple causes on a single effect, human judgments about causal strength and structure can be predicted accurately for relatively simple causal structures. Dynamic models of learning based on the causal framework can explain patterns of acquisition observed with serial presentation of contingency data and are consistent with available neuroimaging data. The approach has been extended to a diverse range of inductive tasks, including category-based and analogical inferences.

New Insights into Signed Path Coefficient Granger Causality Analysis.

Science.gov (United States)

Zhang, Jian; Li, Chong; Jiang, Tianzi

2016-01-01

Granger causality analysis, as a time series analysis technique derived from econometrics, has been applied in an ever-increasing number of publications in the field of neuroscience, including fMRI, EEG/MEG, and fNIRS. The present study mainly focuses on the validity of "signed path coefficient Granger causality," a Granger-causality-derived analysis method that has been adopted by many fMRI researches in the last few years. This method generally estimates the causality effect among the time series by an order-1 autoregression, and defines a positive or negative coefficient as an "excitatory" or "inhibitory" influence. In the current work we conducted a series of computations from resting-state fMRI data and simulation experiments to illustrate the signed path coefficient method was flawed and untenable, due to the fact that the autoregressive coefficients were not always consistent with the real causal relationships and this would inevitablely lead to erroneous conclusions. Overall our findings suggested that the applicability of this kind of causality analysis was rather limited, hence researchers should be more cautious in applying the signed path coefficient Granger causality to fMRI data to avoid misinterpretation.

Granger Causality Testing with Intensive Longitudinal Data.

Science.gov (United States)

Molenaar, Peter C M

2018-06-01

The availability of intensive longitudinal data obtained by means of ambulatory assessment opens up new prospects for prevention research in that it allows the derivation of subject-specific dynamic networks of interacting variables by means of vector autoregressive (VAR) modeling. The dynamic networks thus obtained can be subjected to Granger causality testing in order to identify causal relations among the observed time-dependent variables. VARs have two equivalent representations: standard and structural. Results obtained with Granger causality testing depend upon which representation is chosen, yet no criteria exist on which this important choice can be based. A new equivalent representation is introduced called hybrid VARs with which the best representation can be chosen in a data-driven way. Partial directed coherence, a frequency-domain statistic for Granger causality testing, is shown to perform optimally when based on hybrid VARs. An application to real data is provided.

Causality Between Urban Concentration and Environmental Quality

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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.

Partial Granger causality--eliminating exogenous inputs and latent variables.

Science.gov (United States)

Guo, Shuixia; Seth, Anil K; Kendrick, Keith M; Zhou, Cong; Feng, Jianfeng

2008-07-15

Attempts to identify causal interactions in multivariable biological time series (e.g., gene data, protein data, physiological data) can be undermined by the confounding influence of environmental (exogenous) inputs. Compounding this problem, we are commonly only able to record a subset of all related variables in a system. These recorded variables are likely to be influenced by unrecorded (latent) variables. To address this problem, we introduce a novel variant of a widely used statistical measure of causality--Granger causality--that is inspired by the definition of partial correlation. Our 'partial Granger causality' measure is extensively tested with toy models, both linear and nonlinear, and is applied to experimental data: in vivo multielectrode array (MEA) local field potentials (LFPs) recorded from the inferotemporal cortex of sheep. Our results demonstrate that partial Granger causality can reveal the underlying interactions among elements in a network in the presence of exogenous inputs and latent variables in many cases where the existing conditional Granger causality fails.

Alienígenas na sala: o que fazer com espécies exóticas em trabalhos de taxonomia, florística e fitossociologia? Aliens in the room: what to do with exotic species in taxonomic, floristic and phytosociological studies?

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Marcelo Freire Moro

2012-12-01

Full Text Available A presença cada vez mais disseminada de organismos exóticos (muitos dos quais se tornam invasores nas diferentes regiões do planeta levou ao surgimento de uma linha de pesquisa na ecologia voltada às invasões biológicas. E para permitir a comunicação entre autores também foi desenvolvido um arcabouço terminológico. Mas, apesar disso, a terminologia relativa às bioinvasões tem sido ignorada por boa parte dos botânicos no Brasil. Há uma boa dose de confusão entre botânicos sobre o que seja uma espécie exótica, naturalizada, invasora, daninha e ruderal, levando ao uso inconsistente da terminologia. Além disso, diferentes autores têm adotado posturas praticamente opostas ao lidar com espécies exóticas em suas áreas de estudo, seja na preparação de tratamentos taxonômicos, seja na publicação de levantamentos florísticos e fitossociológicos. Enquanto alguns pesquisadores incluem em floras mesmo espécies cultivadas que não se reproduzem, outros excluem plantas invasoras comuns e conspícuas. Nós apresentamos aqui, em português, os principais conceitos relativos ao tema da bioinvasão e chamamos a atenção dos autores brasileiros para a necessidade de utilizar de modo consistente o arcabouço terminológico já existente na literatura. Também propomos a adoção de rótulos claros para informar quais espécies são exóticas na área estudada, diferenciando-as das nativas, e sugerimos critérios para ajudar botânicos a decidirem quando uma planta exótica deve ou não ser incluída em tratamentos taxonômicos ou levantamentos de florística.The ever-growing presence of exotic organisms (many of which become invasive throughout the planet has led to the emergence of biological invasions as a field of study within ecology. To enable communication between scientists in this field, a terminology has developed. However, this terminology has been ignored by many botanists in Brazil where there is confusion regarding

Inductive reasoning about causally transmitted properties.

Science.gov (United States)

Shafto, Patrick; Kemp, Charles; Bonawitz, Elizabeth Baraff; Coley, John D; Tenenbaum, Joshua B

2008-11-01

Different intuitive theories constrain and guide inferences in different contexts. Formalizing simple intuitive theories as probabilistic processes operating over structured representations, we present a new computational model of category-based induction about causally transmitted properties. A first experiment demonstrates undergraduates' context-sensitive use of taxonomic and food web knowledge to guide reasoning about causal transmission and shows good qualitative agreement between model predictions and human inferences. A second experiment demonstrates strong quantitative and qualitative fits to inferences about a more complex artificial food web. A third experiment investigates human reasoning about complex novel food webs where species have known taxonomic relations. Results demonstrate a double-dissociation between the predictions of our causal model and a related taxonomic model [Kemp, C., & Tenenbaum, J. B. (2003). Learning domain structures. In Proceedings of the 25th annual conference of the cognitive science society]: the causal model predicts human inferences about diseases but not genes, while the taxonomic model predicts human inferences about genes but not diseases. We contrast our framework with previous models of category-based induction and previous formal instantiations of intuitive theories, and outline challenges in developing a complete model of context-sensitive reasoning.

Neural correlates of continuous causal word generation.

Science.gov (United States)

Wende, Kim C; Straube, Benjamin; Stratmann, Mirjam; Sommer, Jens; Kircher, Tilo; Nagels, Arne

2012-09-01

Causality provides a natural structure for organizing our experience and language. Causal reasoning during speech production is a distinct aspect of verbal communication, whose related brain processes are yet unknown. The aim of the current study was to investigate the neural mechanisms underlying the continuous generation of cause-and-effect coherences during overt word production. During fMRI data acquisition participants performed three verbal fluency tasks on identical cue words: A novel causal verbal fluency task (CVF), requiring the production of multiple reasons to a given cue word (e.g. reasons for heat are fire, sun etc.), a semantic (free association, FA, e.g. associations with heat are sweat, shower etc.) and a phonological control task (phonological verbal fluency, PVF, e.g. rhymes with heat are meat, wheat etc.). We found that, in contrast to PVF, both CVF and FA activated a left lateralized network encompassing inferior frontal, inferior parietal and angular regions, with further bilateral activation in middle and inferior as well as superior temporal gyri and the cerebellum. For CVF contrasted against FA, we found greater bold responses only in the left middle frontal cortex. Large overlaps in the neural activations during free association and causal verbal fluency indicate that the access to causal relationships between verbal concepts is at least partly based on the semantic neural network. The selective activation in the left middle frontal cortex for causal verbal fluency suggests that distinct neural processes related to cause-and-effect-relations are associated with the recruitment of middle frontal brain areas. Copyright © 2012 Elsevier Inc. All rights reserved.

Testing causal relationships between wholesale electricity prices and primary energy prices

International Nuclear Information System (INIS)

Nakajima, Tadahiro; Hamori, Shigeyuki

2013-01-01

We apply the lag-augmented vector autoregression technique to test the Granger-causal relationships among wholesale electricity prices, natural gas prices, and crude oil prices. In addition, by adopting a cross-correlation function approach, we test not only the causality in mean but also the causality in variance between the variables. The results of tests using both techniques show that gas prices Granger-cause electricity prices in mean. We find no Granger-causality in variance among these variables. -- Highlights: •We test the Granger-causality among wholesale electricity and primary energy prices. •We test not only the causality in mean but also the causality in variance. •The results show that gas prices Granger-cause electricity prices in mean. •We find no Granger-causality in variance among these variables

World oil and agricultural commodity prices: Evidence from nonlinear causality

International Nuclear Information System (INIS)

Nazlioglu, Saban

2011-01-01

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.

UMA TEORÍA CAUSAL PARA LOS CASOS FREGE

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ABEL WAJNERMAN PAZ

2015-06-01

Full Text Available Fodor ha argumentado a favor de un par de tesis que pueden caracterizarse como constituyendo un dilema: Por un lado, si adoptamos una teoría funcional para los conceptos explicamos semánticamente los casos Frege pero caemos en el holismo semántico. Por otro lado, si adoptamos una teoría causal/informacional evitamos el holismo pero no explicamos los casos Frege semánticamente. Fodor (por ej, 1994, 1998 y 2008 intenta evitar la segunda parte del dilema argumentando que los casos de Frege pueden tener una explicación sintáctica y no semántica. En este trabajo intentaré ofrecer una salida alternativa al dilema fodoriano. Propondré una explicación semántica de los casos Frege que incorpora tanto elementos de una teoría causal como de una de rol funcional. Afirmaré que el contenido cognitivo o estrecho de un concepto (el tipo de contenido aparentemente exigido por los casos Frege es el conjunto de contenidos causales/informacionales de las representaciones que figuran en su rol funcional. Considero que individuar a las representaciones en los roles por medio de sus contenidos causales permite evitar el holismo (evitando el proceso de ramsificación típicamente empleado para individuar a los roles y que identificar el contenido cognitivo con contenidos causales/informacionales de las representaciones en los roles permite evitar el referencialismo de las propuestas causales (podemos distinguir sentido de referencia en términos causales.

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......, eventually rejecting the null hypothesis, even when the series are independent of each other. Moreover, controlling for these deterministic elements (in the auxiliary regressions of the test) does not preclude the possibility of drawing erroneous inferences. Granger-causality tests should not be used under...

Quantum theory and local causality

CERN Document Server

Hofer-Szabó, Gábor

2018-01-01

This book summarizes the results of research the authors have pursued in the past years on the problem of implementing Bell's notion of local causality in local physical theories and relating it to other important concepts and principles in the foundations of physics such as the Common Cause Principle, Bell's inequalities, the EPR (Einstein-Podolsky-Rosen) scenario, and various other locality and causality concepts. The book is intended for philosophers of science with an interest in the formal background of sciences, philosophers of physics and physicists working in foundation of physics.

Quantum causality conceptual issues in the causal theory of quantum mechanics

CERN Document Server

Riggs, Peter J; French, Steven RD

2009-01-01

This is a treatise devoted to the foundations of quantum physics and the role that causality plays in the microscopic world governed by the laws of quantum mechanics. The book is controversial and will engender some lively debate on the various issues raised.

Analise da influencia das fontes de carbono na patogenicidade do Moniliophthora perniciosa pathogenicity em Theobroma cacao

OpenAIRE

Fatima Cerqueira Alvim

2009-01-01

Resumo: O fungo basidiomiceto hemibiotrófico Moniliophthora perniciosa, agente causal da doença vassoura-de-bruxa (VB) em Theobroma cacao, é o principal patógeno da lavoura cacaueira nas Américas e no Caribe. O presente trabalho apresentou como objetivo primordial identificar proteínas relacionadas com a patogenicidade deste fungo. No primeiro capítulo desta tese foi demonstrado o efeito de diferentes fontes de carbono sobre a morfologia e fisiologia do M, perniciosa. O fungo foi crescido em ...

A Causal Model of Faculty Research Productivity.

Science.gov (United States)

Bean, John P.

A causal model of faculty research productivity was developed through a survey of the literature. Models of organizational behavior, organizational effectiveness, and motivation were synthesized into a causal model of productivity. Two general types of variables were assumed to affect individual research productivity: institutional variables and…

Causal inheritance in plane wave quotients

International Nuclear Information System (INIS)

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

2003-01-01

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

Testing the causal theory of reference.

Science.gov (United States)

Domaneschi, Filippo; Vignolo, Massimiliano; Di Paola, Simona

2017-04-01

Theories of reference are a crucial research topic in analytic philosophy. Since the publication of Kripke's Naming and Necessity, most philosophers have endorsed the causal/historical theory of reference. The goal of this paper is twofold: (i) to discuss a method for testing experimentally the causal theory of reference for proper names by investigating linguistic usage and (ii) to present the results from two experiments conducted with that method. Data collected in our experiments confirm the causal theory of reference for people proper names and for geographical proper names. A secondary but interesting result is that the semantic domain affects reference assignment: while with people proper names speakers tend to assign the semantic reference, with geographical proper names they are prompted to assign the speaker's reference. Copyright © 2016 Elsevier B.V. All rights reserved.

Causal inheritance in plane wave quotients

Science.gov (United States)

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

2004-01-01

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 space-time 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 space-times. We show that all other quotients preserve stable causality.

Causal mediation analysis with multiple causally non-ordered mediators.

Science.gov (United States)

Taguri, Masataka; Featherstone, John; Cheng, Jing

2018-01-01

In many health studies, researchers are interested in estimating the treatment effects on the outcome around and through an intermediate variable. Such causal mediation analyses aim to understand the mechanisms that explain the treatment effect. Although multiple mediators are often involved in real studies, most of the literature considered mediation analyses with one mediator at a time. In this article, we consider mediation analyses when there are causally non-ordered multiple mediators. Even if the mediators do not affect each other, the sum of two indirect effects through the two mediators considered separately may diverge from the joint natural indirect effect when there are additive interactions between the effects of the two mediators on the outcome. Therefore, we derive an equation for the joint natural indirect effect based on the individual mediation effects and their interactive effect, which helps us understand how the mediation effect works through the two mediators and relative contributions of the mediators and their interaction. We also discuss an extension for three mediators. The proposed method is illustrated using data from a randomized trial on the prevention of dental caries.

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…

Beyond Markov: Accounting for independence violations in causal reasoning.

Science.gov (United States)

Rehder, Bob

2018-06-01

Although many theories of causal cognition are based on causal graphical models, a key property of such models-the independence relations stipulated by the Markov condition-is routinely violated by human reasoners. This article presents three new accounts of those independence violations, accounts that share the assumption that people's understanding of the correlational structure of data generated from a causal graph differs from that stipulated by causal graphical model framework. To distinguish these models, experiments assessed how people reason with causal graphs that are larger than those tested in previous studies. A traditional common cause network (Y 1 ←X→Y 2 ) was extended so that the effects themselves had effects (Z 1 ←Y 1 ←X→Y 2 →Z 2 ). A traditional common effect network (Y 1 →X←Y 2 ) was extended so that the causes themselves had causes (Z 1 →Y 1 →X←Y 2 ←Z 2 ). Subjects' inferences were most consistent with the beta-Q model in which consistent states of the world-those in which variables are either mostly all present or mostly all absent-are viewed as more probable than stipulated by the causal graphical model framework. Substantial variability in subjects' inferences was also observed, with the result that substantial minorities of subjects were best fit by one of the other models (the dual prototype or a leaky gate models). The discrepancy between normative and human causal cognition stipulated by these models is foundational in the sense that they locate the error not in people's causal reasoning but rather in their causal representations. As a result, they are applicable to any cognitive theory grounded in causal graphical models, including theories of analogy, learning, explanation, categorization, decision-making, and counterfactual reasoning. Preliminary evidence that independence violations indeed generalize to other judgment types is presented. Copyright © 2018 Elsevier Inc. All rights reserved.

Trivariate causality between economic growth, urbanisation and electricity consumption in Angola: Cointegration and causality analysis

International Nuclear Information System (INIS)

Solarin, Sakiru Adebola; Shahbaz, Muhammad

2013-01-01

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

Simplifying Causal Complexity: How Interactions between Modes of Causal Induction and Information Availability Lead to Heuristic-Driven Reasoning

Science.gov (United States)

Grotzer, Tina A.; Tutwiler, M. Shane

2014-01-01

This article considers a set of well-researched default assumptions that people make in reasoning about complex causality and argues that, in part, they result from the forms of causal induction that we engage in and the type of information available in complex environments. It considers how information often falls outside our attentional frame…

Um país à flor da pele: a relação dos brasileiros com o futebol na cobertura da Copa do Mundo pelo jornal The Guardian

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Maria Carolina Vieira

2016-09-01

Full Text Available O jornalismo internacional tem o papel de reportar sobre outros países e culturas, contribuindo, assim, para a construção de um olhar estrangeiro sobre diversos aspectos nacionais. A Copa do Mundo 2014, por sua vez, foi um momento abundante na formação de imagens sobre o país-sede e seus habitantes, já que os holofotes da mídia estavam voltados para o Brasil. Diante destas considerações, este trabalho foca no estudo das representações sobre a relação dos brasileiros com o futebol no The Guardian, tema que se destacou na cobertura do megaevento esportivo no jornal inglês. Utilizando a Análise de Conteúdo, verificou-se que a emotividade e o futebol como algo que significa mais do que um esporte são fatores-chave para o entendimento estrangeiro da relação Brasil x futebol. Esta visão passional, no entanto, não se estende a outros assuntos abordados no período, sugerindo que a postura editorial dos veículos pode influenciar as representações midiáticas tanto quanto seus históricos ou os próprios acontecimentos.

Causal Relationship between Construction Production and GDP in Turkey

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Hakkı Kutay Bolkol

2015-12-01

Full Text Available This study empirically investigates the causal relationship between construction production and GDP for Turkey during 2005Q1-2013Q4 period. Because it is found that, there is no cointegration which means there is no long run relationship between variables, VAR Granger Causality Method is used to test the causality in short run. The findings reveal that, the causality runs from GDP to Building Production and Building Production to Non-Building Production (i.e. bidirectional relationship. Findings of this paper suggest that, because there is no long run relationship between Construction Production (Building and Non-Building and GDP and also in short run the causality runs from GDP to Construction Production, the growth strategy based on mainly Construction Sector growth is not a good idea for Turkey.

Causal Relationship between Construction Production and GDP in Turkey

Directory of Open Access Journals (Sweden)

Hakkı Kutay Bolkol

2015-09-01

Full Text Available This study empirically investigates the causal relationship between construction production and GDP for Turkey during 2005Q1-2013Q4 period. Because it is found that, there is no cointegration which means there is no long run relationship between variables, VAR Granger Causality Method is used to test the causality in short run. The findings reveal that, the causality runs from GDP to Building Production and Building Production to Non-Building Production (i.e. bidirectional relationship. Findings of this paper suggest that, because there is no long run relationship between Construction Production (Building and Non-Building and GDP and also in short run the causality runs from GDP to Construction Production, the growth strategy based on mainly Construction Sector growth is not a good idea for Turkey.

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...

The causal relationship between Foreign Direct Investment (FDI ...

African Journals Online (AJOL)

The causal relationship between Foreign Direct Investment (FDI) and the ... of selected west African countries: Panel ARDL/Granger Causality Analysis. ... among this developing countries and an important revelation for policy implication.

Biologia floral e sistema reprodutivo da erva-baleeira (Varronia curassavica Jacq.

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D. S. BRANDÃO

2015-12-01

Full Text Available RESUMOO conhecimento do sistema reprodutivo é fundamental para a conservação e manejo de uma espécie. O objetivo deste trabalho foi descrever a fenologia da floração, a antese, registrar os insetos visitantes no período de floração, determinar as características morfométricas das flores e o sistema reprodutivo da erva-baleeira, em um ambiente de Cerrado do Norte de Minas Gerais. Entre maio a dezembro de 2012 foi caracterizado o comportamento fenológico da floração. Na análise da fenologia floral foi determinado: o crescimento da inflorescência, o número de flores e frutos por inflorescências. Utilizou-se seis acessos que tiveram dez inflorescências marcadas em cada acesso, totalizando 60 inflorescências. A antese foi determinada utilizando quatro inflorescências em duas plantas. Os visitantes florais foram observados in loco e capturados em três dias consecutivos de coleta. As características morfométricas foram determinadas com paquímetro utilizando 20 flores, sendo cinco flores de quatro acessos. Para determinar o sistema reprodutivo utilizou-se a razão pólen:óvulo (P:O, utilizando 50 flores, sendo 10 flores de cinco acessos em pré-antese. Nas condições de Montes Claros, o crescimento das inflorescências de erva-baleeira ocorreu entre meados de agosto e início de outubro, totalizando 45 dias. O florescimento foi observado entre meados de setembro e final de outubro, enquanto a frutificação ocorreu de meados de outubro a início de dezembro, sendo que ambos ocorreram de forma irregular. A antese floral de erva-baleeira, neste estudo, ocorre entre 7:00 e 11:00 horas. Os insetos visitantes pertencem as ordens Coleoptera, Hemiptera, Diptera e Hymenoptera. As flores apresentaram o diâmetro de 2,13 ± 0,05 (mm, o comprimento de 3,29 ± 0,08 (mm, diâmetro do ovário de 0,70 ± 0,02 (mm, o comprimento do ovário de 2,48 ± 0,12 (mm, o diâmetro da antera de 0,67 ± 0,01(mm e o comprimento da antera de 0,93 ±0

Sensitivity Analysis and Bounding of Causal Effects with Alternative Identifying Assumptions

Science.gov (United States)

Jo, Booil; Vinokur, Amiram D.

2011-01-01

When identification of causal effects relies on untestable assumptions regarding nonidentified parameters, sensitivity of causal effect estimates is often questioned. For proper interpretation of causal effect estimates in this situation, deriving bounds on causal parameters or exploring the sensitivity of estimates to scientifically plausible…

Causal quantum theory and the collapse locality loophole

International Nuclear Information System (INIS)

Kent, Adrian

2005-01-01

Causal quantum theory is an umbrella term for ordinary quantum theory modified by two hypotheses: state vector reduction is a well-defined process, and strict local causality applies. The first of these holds in some versions of Copenhagen quantum theory and need not necessarily imply practically testable deviations from ordinary quantum theory. The second implies that measurement events which are spacelike separated have no nonlocal correlations. To test this prediction, which sharply differs from standard quantum theory, requires a precise definition of state vector reduction. Formally speaking, any precise version of causal quantum theory defines a local hidden variable theory. However, causal quantum theory is most naturally seen as a variant of standard quantum theory. For that reason it seems a more serious rival to standard quantum theory than local hidden variable models relying on the locality or detector efficiency loopholes. Some plausible versions of causal quantum theory are not refuted by any Bell experiments to date, nor is it evident that they are inconsistent with other experiments. They evade refutation via a neglected loophole in Bell experiments--the collapse locality loophole--which exists because of the possible time lag between a particle entering a measurement device and a collapse taking place. Fairly definitive tests of causal versus standard quantum theory could be made by observing entangled particles separated by ≅0.1 light seconds

Causal inference in survival analysis using pseudo-observations.

Science.gov (United States)

Andersen, Per K; Syriopoulou, Elisavet; Parner, Erik T

2017-07-30

Causal inference for non-censored response variables, such as binary or quantitative outcomes, is often based on either (1) direct standardization ('G-formula') or (2) inverse probability of treatment assignment weights ('propensity score'). To do causal inference in survival analysis, one needs to address right-censoring, and often, special techniques are required for that purpose. We will show how censoring can be dealt with 'once and for all' by means of so-called pseudo-observations when doing causal inference in survival analysis. The pseudo-observations can be used as a replacement of the outcomes without censoring when applying 'standard' causal inference methods, such as (1) or (2) earlier. We study this idea for estimating the average causal effect of a binary treatment on the survival probability, the restricted mean lifetime, and the cumulative incidence in a competing risks situation. The methods will be illustrated in a small simulation study and via a study of patients with acute myeloid leukemia who received either myeloablative or non-myeloablative conditioning before allogeneic hematopoetic cell transplantation. We will estimate the average causal effect of the conditioning regime on outcomes such as the 3-year overall survival probability and the 3-year risk of chronic graft-versus-host disease. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Causal Bayes Model of Mathematical Competence in Kindergarten

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Božidar Tepeš

2016-06-01

Full Text Available In this paper authors define mathematical competences in the kindergarten. The basic objective was to measure the mathematical competences or mathematical knowledge, skills and abilities in mathematical education. Mathematical competences were grouped in the following areas: Arithmetic and Geometry. Statistical set consisted of 59 children, 65 to 85 months of age, from the Kindergarten Milan Sachs from Zagreb. The authors describe 13 variables for measuring mathematical competences. Five measuring variables were described for the geometry, and eight measuring variables for the arithmetic. Measuring variables are tasks which children solved with the evaluated results. By measuring mathematical competences the authors make causal Bayes model using free software Tetrad 5.2.1-3. Software makes many causal Bayes models and authors as experts chose the model of the mathematical competences in the kindergarten. Causal Bayes model describes five levels for mathematical competences. At the end of the modeling authors use Bayes estimator. In the results, authors describe by causal Bayes model of mathematical competences, causal effect mathematical competences or how intervention on some competences cause other competences. Authors measure mathematical competences with their expectation as random variables. When expectation of competences was greater, competences improved. Mathematical competences can be improved with intervention on causal competences. Levels of mathematical competences and the result of intervention on mathematical competences can help mathematical teachers.

A General Approach to Causal Mediation Analysis

Science.gov (United States)

Imai, Kosuke; Keele, Luke; Tingley, Dustin

2010-01-01

Traditionally in the social sciences, causal mediation analysis has been formulated, understood, and implemented within the framework of linear structural equation models. We argue and demonstrate that this is problematic for 3 reasons: the lack of a general definition of causal mediation effects independent of a particular statistical model, the…

Causal knowledge and the development of inductive reasoning

OpenAIRE

Bright, Aimée K.; Feeney, Aidan

2014-01-01

We explored the development of sensitivity to causal relations in children’s inductive reasoning. Children (5-, 8-, and 12-year-olds) and adults were given trials in which they decided whether a property known to be possessed by members of one category was also possessed by members of (a) a taxonomically related category or (b) a causally related category. The direction of the causal link was either predictive (prey → predator) or diagnostic (predator → prey), and the property that participan...

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.

Inference of boundaries in causal sets

Science.gov (United States)

Cunningham, William J.

2018-05-01

We investigate the extrinsic geometry of causal sets in (1+1) -dimensional Minkowski spacetime. The properties of boundaries in an embedding space can be used not only to measure observables, but also to supplement the discrete action in the partition function via discretized Gibbons–Hawking–York boundary terms. We define several ways to represent a causal set using overlapping subsets, which then allows us to distinguish between null and non-null bounding hypersurfaces in an embedding space. We discuss algorithms to differentiate between different types of regions, consider when these distinctions are possible, and then apply the algorithms to several spacetime regions. Numerical results indicate the volumes of timelike boundaries can be measured to within 0.5% accuracy for flat boundaries and within 10% accuracy for highly curved boundaries for medium-sized causal sets with N  =  214 spacetime elements.

Spatial hypersurfaces in causal set cosmology

International Nuclear Information System (INIS)

Major, Seth A; Rideout, David; Surya, Sumati

2006-01-01

Within the causal set approach to quantum gravity, a discrete analogue of a spacelike region is a set of unrelated elements, or an antichain. In the continuum approximation of the theory, a moment-of-time hypersurface is well represented by an inextendible antichain. We construct a richer structure corresponding to a thickening of this antichain containing non-trivial geometric and topological information. We find that covariant observables can be associated with such thickened antichains and transitions between them, in classical sequential growth models of causal sets. This construction highlights the difference between the covariant measure on causal set cosmology and the standard sum-over-histories approach: the measure is assigned to completed histories rather than to histories on a restricted spacetime region. The resulting re-phrasing of the sum-over-histories may be fruitful in other approaches to quantum gravity

Analogy in causal inference: rethinking Austin Bradford Hill's neglected consideration.

Science.gov (United States)

Weed, Douglas L

2018-05-01

The purpose of this article was to rethink and resurrect Austin Bradford Hill's "criterion" of analogy as an important consideration in causal inference. In epidemiology today, analogy is either completely ignored (e.g., in many textbooks), or equated with biologic plausibility or coherence, or aligned with the scientist's imagination. None of these examples, however, captures Hill's description of analogy. His words suggest that there may be something gained by contrasting two bodies of evidence, one from an established causal relationship, the other not. Coupled with developments in the methods of systematic assessments of evidence-including but not limited to meta-analysis-analogy can be restructured as a key component in causal inference. This new approach will require that a collection-a library-of known cases of causal inference (i.e., bodies of evidence involving established causal relationships) be developed. This library would likely include causal assessments by organizations such as the International Agency for Research on Cancer, the National Toxicology Program, and the United States Environmental Protection Agency. In addition, a process for describing key features of a causal relationship would need to be developed along with what will be considered paradigm cases of causation. Finally, it will be important to develop ways to objectively compare a "new" body of evidence with the relevant paradigm case of causation. Analogy, along with all other existing methods and causal considerations, may improve our ability to identify causal relationships. Copyright © 2018 Elsevier Inc. All rights reserved.

Multichannel Signal Enhancement using Non-Causal, Time-Domain Filters

DEFF Research Database (Denmark)

Jensen, Jesper Rindom; Christensen, Mads Græsbøll; Benesty, Jacob

2013-01-01

In the vast amount of time-domain filtering methods for speech enhancement, the filters are designed to be causal. Recently, however, it was shown that the noise reduction and signal distortion capabilities of such single-channel filters can be improved by allowing the filters to be non-causal. W......In the vast amount of time-domain filtering methods for speech enhancement, the filters are designed to be causal. Recently, however, it was shown that the noise reduction and signal distortion capabilities of such single-channel filters can be improved by allowing the filters to be non......-causal, multichannel filters for enhancement based on an orthogonal decomposition is proposed. The evaluation shows that there is a potential gain in noise reduction and signal distortion by introducing non-causality. Moreover, experiments on real-life speech show that we can improve the perceptual quality....

Elements of Causal Inference: Foundations and Learning Algorithms

DEFF Research Database (Denmark)

Peters, Jonas Martin; Janzing, Dominik; Schölkopf, Bernhard

A concise and self-contained introduction to causal inference, increasingly important in data science and machine learning......A concise and self-contained introduction to causal inference, increasingly important in data science and machine learning...

Catálogo florístico del término de Ladruñán (Castellote, Maestrazgo, Teruel [Floristic Checklist of Ladruñán (Castellote, Teruel, E Spain

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Antoni AGUILELLA i PALASÍ

2012-07-01

Full Text Available RESUMEN: Se presenta el catalogo florístico del término de Ladruñán, en el Guadalope medio (NE de Teruel, donde la diversidad de hábitats favorece la coexistencia de 694 taxones vegetales, en un área que apenas llega a una tercera parte de una cuadrícula MGRS de 10x10 km. Algunas citas como la de Ridolfia segetum, constituyen una nueva localidad relevante para la flora aragonesa. De cada taxón se dan las cuadrículas MGRS en las que está presente. En algunos casos como Arbutus unedo, Erica multiflora, Juniperus thurifera y Ridolfia segetum, se hacen comentarios adicionales. Palabras clave: Florística, Catálogo, Corología. SUMMARY: Floristic Checklist of Ladruñán (Castellote, Teruel, E Spain. In this work, the checklist of Ladruñán area is presented. The habitats diversity of this territory, from the medium Guadalope River Basin, allows the presence of 693 taxa, with an area near to a third part of a 10x10 km2 MGRS square. Some records, as that of Ridolfia segetum, are a new and relevant record for the flora of Aragón. For every taxon we provided the 10x10 km2 squares were it has been observed or collected. In some cases as Arbutus unedo, Erica multiflora, Juniperus thurifera and Ridolfia segetum, some extra comments are made. Key words: loristics, Checklist, Chorology.

Counterfactual overdetermination vs. the causal exclusion problem.

Science.gov (United States)

Sparber, Georg

2005-01-01

This paper aims to show that a counterfactual approach to causation is not sufficient to provide a solution to the causal exclusion problem in the form of systematic overdetermination. Taking into account the truthmakers of causal counterfactuals provides a strong argument in favour of the identity of causes in situations of translevel, causation.

Non-Bayesian Inference: Causal Structure Trumps Correlation

Science.gov (United States)

Bes, Benedicte; Sloman, Steven; Lucas, Christopher G.; Raufaste, Eric

2012-01-01

The study tests the hypothesis that conditional probability judgments can be influenced by causal links between the target event and the evidence even when the statistical relations among variables are held constant. Three experiments varied the causal structure relating three variables and found that (a) the target event was perceived as more…

Fundamentos do 'Paradigma Metodológico Causal' nas ciências sociais Foundations of the "Causal Methodological Paradigm" in social sciences

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Juan Mario Fandiño Marino

2012-12-01

Full Text Available O presente ensaio trata da lógica subjacente dos chamados 'métodos quantitativos' nas ciências sociais. A especificação desta lógica subjacente se enquadra na tentativa de estabelecer a existência de uma lógica unitária abrangente para as duas abordagens mais gerais da metodologia nas ciências sociais, a saber, a qualitativa e a quantitativa. Esta lógica unitária é procurada a partir da noção de 'paradigmas científicos' de T. Kuhn (1975, sendo que as questões metodológicas representam, por 'hipótese de trabalho', um caso especial de paradigma científico, diferenciando-se dos outros paradigmas na ausência de generalizações simbólicas, anomalias, e 'revoluções', e pelo papel substantivo dos modelos procedimentais, principalmente de fornecimento de evidências. Com este objetivo, o trabalho realiza uma revisão esquemática dos paradigmas Kuhnianos, e depois analisa a tradição metodológica chamada quantitativa nas ciências sociais - especialmente na sociologia - , à luz de tais paradigmas, cunhando a expressão 'paradigma metodológico causal' (PMC. Através, pois, do enquadramento paradigmático das duas abordagens (sendo que a dos métodos qualitativos ainda é deixada para o futuro desta linha de pesquisa, será possível verificar se a interface entre as duas abordagens responde a uma lógica 'metodológica' unitária subjacente; em caso afirmativo se reduziriam - ou até se eliminariam - as respostas conflitantes sobre questões de escolha e combinações entre os dois tipos de práticas, subsidiando a formalização de estratégias do tipo 'quali-quanti'. Note-se, finalmente, que a lógica subjacente ao PMC envolve a combinação da noção de causa, lato sensu, com o modelo experimental e seus desdobramentos, sem que isto pressuponha que o papel instrumental dos métodos qualitativos no próprio PMC passe pela noção de causa, ou pela experimentação, ou por comparações do tipo que for.The present paper

Genetic analisys of a cross of gaillon (Brassica oleracea var. alboglabra with cauliflower (B.oleracea var. botrytis

Directory of Open Access Journals (Sweden)

Vanessa B.M.G. Spini

2000-03-01

Full Text Available The cauliflower (Brassica oleracea var. botrytis is an annual vegetable cultivated in Southern and Southwestern Brazil with limited production in the Northeast and Centralwest. A variety of Chinese kale, "kaai laan" or "gaillon" (Brassica oleracea var. alboglabra, produces seeds at high temperatures and therefore can do so in North and Northeastern Brazil. Gaillon and cauliflower were crossed 55 times using 10 gaillon plants as mothers and 4 cauliflower plants as pollen donors. From these crosses, in the F2 generation, 612 plants with inflorescence like gaillon and 48 plants with inflorescence like cauliflower were obtained, in a proportion similar to 15:1, implying that 2 pairs of genes entered into formation of the cauliflower inflorescence type. In order to study flower color, 339 plants were analyzed: 274 presented white flowers and 65, yellow flowers, denoting that this caracter is determined by 1 pair of genes, white being dominant over yellow; white flowers had a slighly higher adaptive value in our population. The characteristic waxy leaf showed a proportion of 3 waxy plants for 1 not waxy, indicating the action of one pair of genes.A couve-flor (Brassica oleracea var. botrytis é um vegetal anual e tem seu cultivo no Brasil limitado às regiões Sul e Sudeste, com pequena produção no Nordeste e Centro-Oeste. Uma variedade de couve da China, "kaai laan" ou "gaillon" (Brassica oleracea var. alboglabra, produz sementes em altas temperaturas e, portanto, é apta a produzir sementes no Norte e Nordeste do Brasil. Gaillon e couve-flor foram cruzados. Foram feitos 55 cruzamentos usando 10 plantas de gaillon como mãe e 4 plantas de couve-flor como doadores de pólen. Desses cruzamentos, na geração F2, 612 plantas com inflorescência tipo gaillon e 48 plantas com inflorescência tipo couve-flor foram obtidas, em proporção similar a 15:1, demonstrando que 2 pares de genes estão envolvidos na formação da inflorescência em couve-flor

Causality and complexity: the myth of objectivity in science.

Science.gov (United States)

Mikulecky, Donald C

2007-10-01

Two distinctly different worldviews dominate today's thinking in science and in the world of ideas outside of science. Using the approach advocated by Robert M. Hutchins, it is possible to see a pattern of interaction between ideas in science and in other spheres such as philosophy, religion, and politics. Instead of compartmentalizing these intellectual activities, it is worthwhile to look for common threads of mutual influence. Robert Rosen has created an approach to scientific epistemology that might seem radical to some. However, it has characteristics that resemble ideas in other fields, in particular in the writings of George Lakoff, Leo Strauss, and George Soros. Historically, the atmosphere at the University of Chicago during Hutchins' presidency gave rise to Rashevsky's relational biology, which Rosen carried forward. Strauss was writing his political philosophy there at the same time. One idea is paramount in all this, and it is Lakoff who gives us the most insight into how the worldviews differ using this idea. The central difference has to do with causality, the fundamental concept that we use to build a worldview. Causal entailment has two distinct forms in Lakoff 's analysis: direct causality and complex causality. Rosen's writings on complexity create a picture of complex causality that is extremely useful in its detail, grounding in the ideas of Aristotle. Strauss asks for a return to the ancients to put philosophy back on track. Lakoff sees the weaknesses in Western philosophy in a similar way, and Rosen provides tools for dealing with the problem. This introduction to the relationships between the thinking of these authors is meant to stimulate further discourse on the role of complex causal entailment in all areas of thought, and how it brings them together in a holistic worldview. The worldview built on complex causality is clearly distinct from that built around simple, direct causality. One important difference is that the impoverished causal

Causal Relations and Feature Similarity in Children's Inductive Reasoning

Science.gov (United States)

Hayes, Brett K.; Thompson, Susan P.

2007-01-01

Four experiments examined the development of property induction on the basis of causal relations. In the first 2 studies, 5-year-olds, 8-year-olds, and adults were presented with triads in which a target instance was equally similar to 2 inductive bases but shared a causal antecedent feature with 1 of them. All 3 age groups used causal relations…

Causality and subjectivity in discourse : The meaning and use of causal connectives in spontaneous conversation, chat interactions and written text

NARCIS (Netherlands)

Sanders, T.J.M.|info:eu-repo/dai/nl/075243911; Spooren, W.P.M.S.

Many languages of the world have connectives to express causal relations at the discourse level. Often, language users systematically prefer one lexical item (because) over another (even highly similar) one (since) to express a causal relationship. Such choices provide a window on speakers'

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…

Florística e fitossociologia de uma floresta de vertente na Amazônia Central, Amazonas, Brasil Floristic and phytosociology of a slope forest in Central Amazonia, Amazonas, Brazil

Directory of Open Access Journals (Sweden)

Arlem Nascimento de Oliveira

2004-01-01

Full Text Available O estudo florístico e fitossociológico de árvores, palmeiras e lianas com diâmetro à altura do peito (DAP >10 cm, em uma floresta de vertente na Amazônia Central (2º35'45" S e 60º12'40" W, foi realizado empregando-se 20 parcelas de 50 x 10 m, distribuídas em dois transectos paralelos de 500 x 10 m. Foram registrados 771 indivíduos, pertencentes a 50 famílias, 120 gêneros e 239 espécies. Das espécies amostradas, 44% são "localmente raras". Sapotaceae, Lecythidaceae, Fabaceae, Caesalpiniaceae e Chrysobalanaceae constituíram as cinco famílias com maior riqueza de espécies e número de indivíduos. Dos 771 indivíduos amostrados, mais de 65% apresentaram DAP > 20 cm. As espécies Eschweilera bracteosa e Protium apiculatum apresentaram os maiores valores de IVI. Cerca de 83% das espécies encontram-se distribuídas aleatoriamente no hectare amostrado. O índice de diversidade Shannon-Wiener foi de 5,01 nats.indivíduo-1, com uniformidade de 0,91, valores altos no contexto de levantamentos semelhantes na região. A heterogeneidade edáfica e topográfica da área, as taxas de recrutamento de novos indivíduos e de espécies "localmente raras" à comunidade local, podem ter contribuído para as altas dissimilaridade (36,2% e diversidade florísticas documentadas neste estudo.The floristic and phytosociological study of trees, palms and lianas with diameter at breast height (DBH >10 cm in a forest slope in Central Amazonia (2º35'45 "S and 60º12'40" W was carried out using 20 plots of 50 x 10 m, distributed in two parallel transects of 500 x 10 m. A total of 771 plants were registered, belonging to 50 families, 120 genera and 239 species. Of the sampled species, 44% are locally rare. Families with the most species and number of individuals were Sapotaceae, Lecythidaceae, Fabaceae, Caesalpiniaceae and Chrysobalanaceae. More than 65% of the sampled plants had DBH > 20 cm. Eschweilera bracteosa and Protium apiculatum were the most

Increasing fMRI sampling rate improves Granger causality estimates.

Directory of Open Access Journals (Sweden)

Fa-Hsuan Lin

Full Text Available Estimation of causal interactions between brain areas is necessary for elucidating large-scale functional brain networks underlying behavior and cognition. Granger causality analysis of time series data can quantitatively estimate directional information flow between brain regions. Here, we show that such estimates are significantly improved when the temporal sampling rate of functional magnetic resonance imaging (fMRI is increased 20-fold. Specifically, healthy volunteers performed a simple visuomotor task during blood oxygenation level dependent (BOLD contrast based whole-head inverse imaging (InI. Granger causality analysis based on raw InI BOLD data sampled at 100-ms resolution detected the expected causal relations, whereas when the data were downsampled to the temporal resolution of 2 s typically used in echo-planar fMRI, the causality could not be detected. An additional control analysis, in which we SINC interpolated additional data points to the downsampled time series at 0.1-s intervals, confirmed that the improvements achieved with the real InI data were not explainable by the increased time-series length alone. We therefore conclude that the high-temporal resolution of InI improves the Granger causality connectivity analysis of the human brain.

Inference of Boundaries in Causal Sets

OpenAIRE

Cunningham, William

2017-01-01

We investigate the extrinsic geometry of causal sets in $(1+1)$-dimensional Minkowski spacetime. The properties of boundaries in an embedding space can be used not only to measure observables, but also to supplement the discrete action in the partition function via discretized Gibbons-Hawking-York boundary terms. We define several ways to represent a causal set using overlapping subsets, which then allows us to distinguish between null and non-null bounding hypersurfaces in an embedding space...

Causal Relationship Between Relative Price Variability and Inflation in Turkey:

Directory of Open Access Journals (Sweden)

Nebiye Yamak

2016-09-01

Full Text Available This study investigates the causal relationship between inflation and relative price variability in Turkey for the period of January 2003-January 2014, by using panel data. In the study, a Granger (1969 non-causality test in heterogeneous panel data models developed by Dumitrescu and Hurlin (2012 is utilized to determine the causal relations between inflation rate relative price variability. The panel data consists of 4123 observations: 133 time observations and 31 cross-section observations. The results of panel causality test indicate that there is a bidirectional causality between inflation rate and relative price variability by not supporting the imperfection information model of Lucas and the menu cost model of Ball and Mankiw.

Causality and prediction: differences and points of contact

Directory of Open Access Journals (Sweden)

Luis Carlos Silva Ayçaguer, PhD

2014-09-01

Full Text Available This contribution presents the differences between those variables that might play a causal role in a certain process and those only valuable for predicting the outcome. Some considerations are made about the core intervention of the association and the temporal precedence and biases in both cases, the study of causality and predictive modeling. In that context, several relevant aspects related to the design of the corresponding studies are briefly reviewed and some of the mistakes that are often committed in handling both, causality and prediction, are illustrated.

Cortical hierarchies perform Bayesian causal inference in multisensory perception.

Directory of Open Access Journals (Sweden)

Tim Rohe

2015-02-01

Full Text Available To form a veridical percept of the environment, the brain needs to integrate sensory signals from a common source but segregate those from independent sources. Thus, perception inherently relies on solving the "causal inference problem." Behaviorally, humans solve this problem optimally as predicted by Bayesian Causal Inference; yet, the underlying neural mechanisms are unexplored. Combining psychophysics, Bayesian modeling, functional magnetic resonance imaging (fMRI, and multivariate decoding in an audiovisual spatial localization task, we demonstrate that Bayesian Causal Inference is performed by a hierarchy of multisensory processes in the human brain. At the bottom of the hierarchy, in auditory and visual areas, location is represented on the basis that the two signals are generated by independent sources (= segregation. At the next stage, in posterior intraparietal sulcus, location is estimated under the assumption that the two signals are from a common source (= forced fusion. Only at the top of the hierarchy, in anterior intraparietal sulcus, the uncertainty about the causal structure of the world is taken into account and sensory signals are combined as predicted by Bayesian Causal Inference. Characterizing the computational operations of signal interactions reveals the hierarchical nature of multisensory perception in human neocortex. It unravels how the brain accomplishes Bayesian Causal Inference, a statistical computation fundamental for perception and cognition. Our results demonstrate how the brain combines information in the face of uncertainty about the underlying causal structure of the world.

Fatores determinantes da capacidade funcional entre idosos

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Tereza Etsuko da Costa Rosa

2003-02-01

Full Text Available OBJETIVO; Investigar a influência de fatores socioeconômicos e demográficos relativos à saúde, bem como os fatores ligados às atividades sociais e à avaliação subjetiva da saúde sobre a capacidade funcional dos idosos. MÉTODOS: Estudo transversal, integrante de estudo multicêntrico, em amostra representativa do município de São Paulo, realizado em 1989. A capacidade funcional foi avaliada através da escala de atividades da vida diária pessoal e instrumental e investigada como variável dicotômica: ausência de dependência - incapacidade/dificuldade em nenhuma das atividades versus presença de dependência moderada/grave - incapacidade/dificuldade em 4 ou mais atividades. Análise de regressão logística múltipla foi aplicada aos fatores hierarquicamente agrupados. RESULTADOS: As características que se associaram com a dependência moderada/grave foram analfabetismo, ser aposentado, ser pensionista, ser dona de casa, não ser proprietário da moradia, ter mais de 65 anos, ter composição familiar multigeracional, ter sido internado nos últimos 6 meses, ser "caso" no rastreamento de saúde mental, não visitar amigos, ter problemas de visão, ter história de derrame, não visitar parentes e ter avaliação pessimista da saúde ao se comparar com seus pares. CONCLUSÕES: As características identificadas que se associaram à dependência moderada/grave sugerem uma complexa rede causal do declínio da capacidade funcional. Pode-se supor, entretanto, que ações preventivas especificamente voltadas para certos fatores podem propiciar benefícios para o prolongamento do bem estar da população idosa.

Fatores determinantes da capacidade funcional entre idosos

Directory of Open Access Journals (Sweden)

Rosa Tereza Etsuko da Costa

2003-01-01

Full Text Available OBJETIVO; Investigar a influência de fatores socioeconômicos e demográficos relativos à saúde, bem como os fatores ligados às atividades sociais e à avaliação subjetiva da saúde sobre a capacidade funcional dos idosos. MÉTODOS: Estudo transversal, integrante de estudo multicêntrico, em amostra representativa do município de São Paulo, realizado em 1989. A capacidade funcional foi avaliada através da escala de atividades da vida diária pessoal e instrumental e investigada como variável dicotômica: ausência de dependência - incapacidade/dificuldade em nenhuma das atividades versus presença de dependência moderada/grave - incapacidade/dificuldade em 4 ou mais atividades. Análise de regressão logística múltipla foi aplicada aos fatores hierarquicamente agrupados. RESULTADOS: As características que se associaram com a dependência moderada/grave foram analfabetismo, ser aposentado, ser pensionista, ser dona de casa, não ser proprietário da moradia, ter mais de 65 anos, ter composição familiar multigeracional, ter sido internado nos últimos 6 meses, ser "caso" no rastreamento de saúde mental, não visitar amigos, ter problemas de visão, ter história de derrame, não visitar parentes e ter avaliação pessimista da saúde ao se comparar com seus pares. CONCLUSÕES: As características identificadas que se associaram à dependência moderada/grave sugerem uma complexa rede causal do declínio da capacidade funcional. Pode-se supor, entretanto, que ações preventivas especificamente voltadas para certos fatores podem propiciar benefícios para o prolongamento do bem estar da população idosa.

Composição da comunidade de diatomáceas periféricas do rio Jaú, Amazonas, Brasil Composition of the periphytic diatom community of the Jaú river, Amazonas, Brazil

Directory of Open Access Journals (Sweden)

José Gerley Díaz-Castro

2003-12-01

Full Text Available Foi realizado um estudo da flora perifítica de diatomáceas (Bacillariophyceae existente no Rio Jaú, tributário do Rio Negro, Amazônia (2º57'S e 61º49'W. As coletas foram realizadas manualmente nas cheias de 1995, 1996 e 1997, e as lâminas permanentes encontram-se depositadas no Herbário FLOR, Universidade Federal de Santa Catarina. Foram identificados 60 táxons específicos e infra-específicos, distribuidos em 16 gêneros e 13 famílias. Eunotiaceae foi a família melhor representada, com 43,3% do total dos táxons inventariados, seguida de Pinnulariaceae com 21,6% e Surirellaceae com 11,6%. O gênero Eunotia destacou-se dentre os demais com 20 táxons. Eunotia e Pinnularia foram os gêneros mais abundantes da flora diatomológica e os que apresentaram maior variação morfológica. Para cada táxon identificado foi feita uma revisão de literatura que incluem diversos aspectos ecológicos.The periphytic diatom flora of the Jaú River, a tributary of the Negro River, in Amazonia (2º 57' S; 61º49' W was studied. Algae were collected manually during the high water periods of 1995, 1996 and 1997 and permanent slides prepared from this material were deposited in the FLOR Herbarium of the Federal University of Santa Catarina. Sixty specific and infra-specific taxa were identified, distributed among 16 genuses and 13 families. Eunotiaceae was the best represented family, with 43.3% of all taxa inventoried, followed by Pinnulariaceae with 21.6% and Surirellaceae with 11.6%. Accounting for 20 taxa. Eunotia and Pinnularia were the dominant genuses and showed the broadest morphological variation. Eunotia was the best. The relevant literature for each taxon was reveiwed and discussed.

Whose statistical reasoning is facilitated by a causal structure intervention?

Science.gov (United States)

McNair, Simon; Feeney, Aidan

2015-02-01

People often struggle when making Bayesian probabilistic estimates on the basis of competing sources of statistical evidence. Recently, Krynski and Tenenbaum (Journal of Experimental Psychology: General, 136, 430-450, 2007) proposed that a causal Bayesian framework accounts for peoples' errors in Bayesian reasoning and showed that, by clarifying the causal relations among the pieces of evidence, judgments on a classic statistical reasoning problem could be significantly improved. We aimed to understand whose statistical reasoning is facilitated by the causal structure intervention. In Experiment 1, although we observed causal facilitation effects overall, the effect was confined to participants high in numeracy. We did not find an overall facilitation effect in Experiment 2 but did replicate the earlier interaction between numerical ability and the presence or absence of causal content. This effect held when we controlled for general cognitive ability and thinking disposition. Our results suggest that clarifying causal structure facilitates Bayesian judgments, but only for participants with sufficient understanding of basic concepts in probability and statistics.

Modeling of causality with metamaterials

International Nuclear Information System (INIS)

Smolyaninov, Igor I

2013-01-01

Hyperbolic metamaterials may be used to model a 2 + 1-dimensional Minkowski space–time in which the role of time is played by one of the spatial coordinates. When a metamaterial is built and illuminated with a coherent extraordinary laser beam, the stationary pattern of light propagation inside the metamaterial may be treated as a collection of particle world lines, which represents a complete ‘history’ of this 2 + 1-dimensional space–time. While this model may be used to build interesting space–time analogs, such as metamaterial ‘black holes’ and a metamaterial ‘big bang’, it lacks causality: since light inside the metamaterial may propagate back and forth along the ‘timelike’ spatial coordinate, events in the ‘future’ may affect events in the ‘past’. Here we demonstrate that a more sophisticated metamaterial model may fix this deficiency via breaking the mirror and temporal (PT) symmetries of the original model and producing one-way propagation along the ‘timelike’ spatial coordinate. The resulting 2 + 1-dimensional Minkowski space–time appears to be causal. This scenario may be considered as a metamaterial model of the Wheeler–Feynman absorber theory of causality. (paper)

Electricity consumption-real GDP causality nexus: Evidence from a bootstrapped causality test for 30 OECD countries

International Nuclear Information System (INIS)

Narayan, Paresh Kumar; Prasad, Arti

2008-01-01

The goal of this paper is to examine any causal effects between electricity consumption and real GDP for 30 OECD countries. We use a bootstrapped causality testing approach and unravel evidence in favour of electricity consumption causing real GDP in Australia, Iceland, Italy, the Slovak Republic, the Czech Republic, Korea, Portugal, and the UK. The implication is that electricity conservation policies will negatively impact real GDP in these countries. However, for the rest of the 22 countries our findings suggest that electricity conversation policies will not affect real GDP

TendÃncias granulomÃtricas dos sedimentos de fundo no Rio Marrecas, regiÃo Sudoeste do ParanÃ

OpenAIRE

Constantino EleuthÃrio da Luz

2011-01-01

A presente dissertaÃÃo trata sobre a variaÃÃo longitudinal das caracterÃsticas texturais dos sedimentos de fundo no rio Marrecas, localizado na regiÃo Sudoeste do ParanÃ. A Ãrea da bacia do rio Marrecas possui 865,43 km2 e abarca parte dos municÃpios de Francisco BeltrÃo, Marmeleiro, Flor da Serra do Sul, Verà e Itapejara DâOeste. O total da bacia do rio Marrecas està inserida em terrenos de idade cretÃcea formada por rochas basÃlticas da formaÃÃo Serra Geral que formam planaltos caracterizad...

Non-Causal Time-Domain Filters for Single-Channel Noise Reduction

DEFF Research Database (Denmark)

Jensen, Jesper Rindom; Benesty, Jacob; Christensen, Mads Græsbøll

2012-01-01

suppression and signal distortion by allowing the filters to be non-causal. Non-causal time-domain filters require knowledge of the future, and are therefore not directly implementable. If the observed signal is processed in blocks, however, the non-causal filters are implementable. In this paper, we propose...

Causal Effect Inference with Deep Latent-Variable Models

NARCIS (Netherlands)

Louizos, C; Shalit, U.; Mooij, J.; Sontag, D.; Zemel, R.; Welling, M.

2017-01-01

Learning individual-level causal effects from observational data, such as inferring the most effective medication for a specific patient, is a problem of growing importance for policy makers. The most important aspect of inferring causal effects from observational data is the handling of

Causal inference in survival analysis using pseudo-observations

DEFF Research Database (Denmark)

Andersen, Per K; Syriopoulou, Elisavet; Parner, Erik T

2017-01-01

Causal inference for non-censored response variables, such as binary or quantitative outcomes, is often based on either (1) direct standardization ('G-formula') or (2) inverse probability of treatment assignment weights ('propensity score'). To do causal inference in survival analysis, one needs ...

Causal Indicators Can Help to Interpret Factors

Science.gov (United States)

Bentler, Peter M.

2016-01-01

The latent factor in a causal indicator model is no more than the latent factor of the factor part of the model. However, if the causal indicator variables are well-understood and help to improve the prediction of individuals' factor scores, they can help to interpret the meaning of the latent factor. Aguirre-Urreta, Rönkkö, and Marakas (2016)…

QED representation for the net of causal loops

Science.gov (United States)

Ciolli, Fabio; Ruzzi, Giuseppe; Vasselli, Ezio

2015-06-01

The present work tackles the existence of local gauge symmetries in the setting of Algebraic Quantum Field Theory (AQFT). The net of causal loops, previously introduced by the authors, is a model independent construction of a covariant net of local C*-algebras on any 4-dimensional globally hyperbolic space-time, aimed to capture structural properties of any reasonable quantum gauge theory. Representations of this net can be described by causal and covariant connection systems, and local gauge transformations arise as maps between equivalent connection systems. The present paper completes these abstract results, realizing QED as a representation of the net of causal loops in Minkowski space-time. More precisely, we map the quantum electromagnetic field Fμν, not free in general, into a representation of the net of causal loops and show that the corresponding connection system and the local gauge transformations find a counterpart in terms of Fμν.

Causal learning is collaborative: Examining explanation and exploration in social contexts.

Science.gov (United States)

Legare, Cristine H; Sobel, David M; Callanan, Maureen

2017-10-01

Causal learning in childhood is a dynamic and collaborative process of explanation and exploration within complex physical and social environments. Understanding how children learn causal knowledge requires examining how they update beliefs about the world given novel information and studying the processes by which children learn in collaboration with caregivers, educators, and peers. The objective of this article is to review evidence for how children learn causal knowledge by explaining and exploring in collaboration with others. We review three examples of causal learning in social contexts, which elucidate how interaction with others influences causal learning. First, we consider children's explanation-seeking behaviors in the form of "why" questions. Second, we examine parents' elaboration of meaning about causal relations. Finally, we consider parents' interactive styles with children during free play, which constrains how children explore. We propose that the best way to understand children's causal learning in social context is to combine results from laboratory and natural interactive informal learning environments.

Human Papilloma Viruses and Breast Cancer - Assessment of Causality.

Science.gov (United States)

Lawson, James Sutherland; Glenn, Wendy K; Whitaker, Noel James

2016-01-01

High risk human papilloma viruses (HPVs) may have a causal role in some breast cancers. Case-control studies, conducted in many different countries, consistently indicate that HPVs are more frequently present in breast cancers as compared to benign breast and normal breast controls (odds ratio 4.02). The assessment of causality of HPVs in breast cancer is difficult because (i) the HPV viral load is extremely low, (ii) HPV infections are common but HPV associated breast cancers are uncommon, and (iii) HPV infections may precede the development of breast and other cancers by years or even decades. Further, HPV oncogenesis can be indirect. Despite these difficulties, the emergence of new evidence has made the assessment of HPV causality, in breast cancer, a practical proposition. With one exception, the evidence meets all the conventional criteria for a causal role of HPVs in breast cancer. The exception is "specificity." HPVs are ubiquitous, which is the exact opposite of specificity. An additional reservation is that the prevalence of breast cancer is not increased in immunocompromised patients as is the case with respect to HPV-associated cervical cancer. This indicates that HPVs may have an indirect causal influence in breast cancer. Based on the overall evidence, high-risk HPVs may have a causal role in some breast cancers.

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

Causality and skies: is non-refocussing necessary?

International Nuclear Information System (INIS)

Bautista, A; Ibort, A; Lafuente, J

2015-01-01

The causal structure of a strongly causal, null pseudo-convex, space-time M is completely characterized in terms of a partial order on its space of skies defined by means of a class of non-negative Legendrian isotopies called sky isotopies. It is also shown that such partial order is determined by the class of future causal celestial curves, that is, curves in the space of light rays which are tangent to skies and such that they determine non-negative sky isotopies. It will also be proved that the space of skies Σ equipped with Low’s (or reconstructive) topology is homeomorphic and diffeomorphic to M under the only additional assumption that M separates skies, that is, that different events determine different skies. The sky-separating property of M is sharp and the previous result provides an answer to the question about the class of space-times whose causal structure, topological and differentiable structure can be reconstructed from their spaces of light rays and skies. These results can be understood as a Malament–Hawking-like theorem stated in terms of the partial order defined on the space of skies. (paper)

A quantum probability model of causal reasoning

Directory of Open Access Journals (Sweden)

Jennifer S Trueblood

2012-05-01

Full Text Available People can often outperform statistical methods and machine learning algorithms in situations that involve making inferences about the relationship between causes and effects. While people are remarkably good at causal reasoning in many situations, there are several instances where they deviate from expected responses. This paper examines three situations where judgments related to causal inference problems produce unexpected results and describes a quantum inference model based on the axiomatic principles of quantum probability theory that can explain these effects. Two of the three phenomena arise from the comparison of predictive judgments (i.e., the conditional probability of an effect given a cause with diagnostic judgments (i.e., the conditional probability of a cause given an effect. The third phenomenon is a new finding examining order effects in predictive causal judgments. The quantum inference model uses the notion of incompatibility among different causes to account for all three phenomena. Psychologically, the model assumes that individuals adopt different points of view when thinking about different causes. The model provides good fits to the data and offers a coherent account for all three causal reasoning effects thus proving to be a viable new candidate for modeling human judgment.

Scalar field Green functions on causal sets

International Nuclear Information System (INIS)

Nomaan Ahmed, S; Surya, Sumati; Dowker, Fay

2017-01-01

We examine the validity and scope of Johnston’s models for scalar field retarded Green functions on causal sets in 2 and 4 dimensions. As in the continuum, the massive Green function can be obtained from the massless one, and hence the key task in causal set theory is to first identify the massless Green function. We propose that the 2d model provides a Green function for the massive scalar field on causal sets approximated by any topologically trivial 2-dimensional spacetime. We explicitly demonstrate that this is indeed the case in a Riemann normal neighbourhood. In 4d the model can again be used to provide a Green function for the massive scalar field in a Riemann normal neighbourhood which we compare to Bunch and Parker’s continuum Green function. We find that the same prescription can also be used for de Sitter spacetime and the conformally flat patch of anti-de Sitter spacetime. Our analysis then allows us to suggest a generalisation of Johnston’s model for the Green function for a causal set approximated by 3-dimensional flat spacetime. (paper)

Causal Scale of Rotors in a Cardiac System

Science.gov (United States)

Ashikaga, Hiroshi; Prieto-Castrillo, Francisco; Kawakatsu, Mari; Dehghani, Nima

2018-04-01

Rotors of spiral waves are thought to be one of the potential mechanisms that maintain atrial fibrillation (AF). However, disappointing clinical outcomes of rotor mapping and ablation to eliminate AF raise a serious doubt on rotors as a macro-scale mechanism that causes the micro-scale behavior of individual cardiomyocytes to maintain spiral waves. In this study, we aimed to elucidate the causal relationship between rotors and spiral waves in a numerical model of cardiac excitation. To accomplish the aim, we described the system in a series of spatiotemporal scales by generating a renormalization group, and evaluated the causal architecture of the system by quantifying causal emergence. Causal emergence is an information-theoretic metric that quantifies emergence or reduction between micro- and macro-scale behaviors of a system by evaluating effective information at each scale. We found that the cardiac system with rotors has a spatiotemporal scale at which effective information peaks. A positive correlation between the number of rotors and causal emergence was observed only up to the scale of peak causation. We conclude that rotors are not the universal mechanism to maintain spiral waves at all spatiotemporal scales. This finding may account for the conflicting benefit of rotor ablation in clinical studies.

Norms and customs: causally important or causally impotent?

Science.gov (United States)

Jones, Todd

2010-01-01

In this article, I argue that norms and customs, despite frequently being described as being causes of behavior in the social sciences and ordinary conversation, cannot really cause behavior. Terms like "norms" and the like seem to refer to philosophically disreputable disjunctive properties. More problematically, even if they do not, or even if there can be disjunctive properties after all, I argue that norms and customs still cannot cause behavior. The social sciences would be better off without referring to properties like norms and customs as if they could be causal.

Causal reasoning and models of cognitive tasks for naval nuclear power plant operators; Raisonnement causal et modelisation de l`activite cognitive d`operateurs de chaufferie nucleaire navale

Energy Technology Data Exchange (ETDEWEB)

Salazar-Ferrer, P

1995-06-01

In complex industrial process control, causal reasoning appears as a major component in operators` cognitive tasks. It is tightly linked to diagnosis, prediction of normal and failure states, and explanation. This work provides a detailed review of literature in causal reasoning. A synthesis is proposed as a model of causal reasoning in process control. This model integrates distinct approaches in Cognitive Science: especially qualitative physics, Bayesian networks, knowledge-based systems, and cognitive psychology. Our model defines a framework for the analysis of causal human errors in simulated naval nuclear power plant fault management. Through the methodological framework of critical incident analysis we define a classification of errors and difficulties linked to causal reasoning. This classification is based on shallow characteristics of causal reasoning. As an origin of these errors, more elementary component activities in causal reasoning are identified. The applications cover the field of functional specification for man-machine interfaces, operators support systems design as well as nuclear safety. In addition of this study, we integrate the model of causal reasoning in a model of cognitive task in process control. (authors). 106 refs., 49 figs., 8 tabs.

BioCause: Annotating and analysing causality in the biomedical domain.

Science.gov (United States)

Mihăilă, Claudiu; Ohta, Tomoko; Pyysalo, Sampo; Ananiadou, Sophia

2013-01-16

Biomedical corpora annotated with event-level information represent an important resource for domain-specific information extraction (IE) systems. However, bio-event annotation alone cannot cater for all the needs of biologists. Unlike work on relation and event extraction, most of which focusses on specific events and named entities, we aim to build a comprehensive resource, covering all statements of causal association present in discourse. Causality lies at the heart of biomedical knowledge, such as diagnosis, pathology or systems biology, and, thus, automatic causality recognition can greatly reduce the human workload by suggesting possible causal connections and aiding in the curation of pathway models. A biomedical text corpus annotated with such relations is, hence, crucial for developing and evaluating biomedical text mining. We have defined an annotation scheme for enriching biomedical domain corpora with causality relations. This schema has subsequently been used to annotate 851 causal relations to form BioCause, a collection of 19 open-access full-text biomedical journal articles belonging to the subdomain of infectious diseases. These documents have been pre-annotated with named entity and event information in the context of previous shared tasks. We report an inter-annotator agreement rate of over 60% for triggers and of over 80% for arguments using an exact match constraint. These increase significantly using a relaxed match setting. Moreover, we analyse and describe the causality relations in BioCause from various points of view. This information can then be leveraged for the training of automatic causality detection systems. Augmenting named entity and event annotations with information about causal discourse relations could benefit the development of more sophisticated IE systems. These will further influence the development of multiple tasks, such as enabling textual inference to detect entailments, discovering new facts and providing new

Evolución de la composición florística Post-fuego en un carrascal de Navarra (n de España

Directory of Open Access Journals (Sweden)

Cavero, R. Y.

1999-12-01

Full Text Available This paper presents results about floristic composition dynamics during four years after controlled fires in a Mediterranean pin-oak wood in Navarra (N Spain. The samples have been taken from eight permanent 1 m² plots subjected to different treatments: different fire type, different situation on the field, and with or without not fired soil addition. The regeneration strategies of the species and the influence of the different treatments on the flora are analyzed. The floristic composition dynamics follows a general model: the species began to appear progressively. The number of species grows gradually to reach a maximum between one and three years after the fire. Later, the number of species diminishes. Post fire species are those that existed before the fire, that is to say, there is an autosuccession process.

[es] Se presentan los resultados de cuatro años de estudio sobre la evolución de la composición florística de un carrascal mediterráneo sometido a fuegos controlados en Navarra (N de España. Los muestreos se han llevado a cabo en ocho cuadrados permanentes de 1 m² de superficie, cada uno sometido a distinto tratamiento: distinto tipo de fuego, distinta situación en la parcela y adición o no de suelo no quemado. Se analizan la estrategia de regeneración de las especies que aparecen después de los fuegos y la influencia de los tratamientos en la regeneración de la flora. La evolución de la composición florística sigue un modelo general: las especies empiezan a aparecer progresivamente, su número crece hasta obtener un máximo entre el año y los cuatro años después de los fuegos, a partir del cual disminuye. Las especies que aparecen son las mismas que había previamente, es decir, se da un proceso de autosucesión. [fr] On présente les résultats de quatre ans d'étude sur l'évolution de la composition floristique d'un bois de chêne vert méditerranéen soumis à des feux contr

Theories of conduct disorder: a causal modelling analysis

NARCIS (Netherlands)

Krol, N.P.C.M.; Morton, J.; Bruyn, E.E.J. De

2004-01-01

Background: If a clinician has to make decisions on diagnosis and treatment, he or she is confronted with a variety of causal theories. In order to compare these theories a neutral terminology and notational system is needed. The Causal Modelling framework involving three levels of description –

O Complexo Vegetacional da Zona Litorânea no Ceará: Pecém, São Gonçalo do Amarante The vegetation complex of the coastal zone of Ceará: Pecém, São Gonçalo do Amarante

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Antônio Sérgio Farias Castro

2012-03-01

Full Text Available O Litoral Setentrional do Nordeste (LSN por sua localização geográfica apresenta clima mais quente e seco do que na costa leste do Brasil. Por sua proximidade com a caatinga e o cerrado, o LSN permite a co-existência de espécies destes Domínios conjuntamente com espécies de restinga, em diferentes formações, constituindo um Complexo Vegetacional. Apesar da grande importância ecológica e botânica deste ecótono, existem poucos estudos sobre a flora regional. O objetivo deste trabalho foi aprofundar o conhecimento sobre a composição florística e fitossociológica da região. Para isso, fizemos um levantamento florístico na área (entre 2007-2011, bem como consultas a registros de herbário na região e um levantamento fitossociológico em um trecho da floresta estacional semidecídua costeira (mata de tabuleiro. Foram inventariadas 382 espécies vegetais, pertencentes a 96 famílias. Na parcela fitossociológica (0,32 ha foram registrados 2.970 indivíduos de 52 espécies, sendo as mais abundantes as arbóreas Manilkara triflora, Chamaecrista ensiformis e Guapira nitida e as arbustivas Cordiera sessilis e Maytenus erythroxyla (altura média 3,8 m, diâmetro médio 6,2 cm, área basal 39,28 m²/ha. A flora local inclui elementos florísticos de caatinga, cerrado e restinga, sugerindo que a comunidade vegetal na região costeira do Ceará possui natureza ecotonal.Due to its geographical location, the northeastern Coast of Brazil (Litoral Setentrional do Nordeste - LSN is a hotter and drier climate than the eastern coast. In addition, because of its proximity to caatinga and cerrado, the LSN contains species from these vegetation biomes and from the restinga on the coast, which comprise different plant formations and creates a vegetation complex. Despite the great importance of this ecotone, there are few studies about its flora. The objective of this work was to contribute to what is known about the floristic and phytosociological

Violation of causality in f(T) gravity

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Otalora, G. [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Valparaiso (Chile); Reboucas, M.J. [Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, RJ (Brazil)

2017-11-15

In the standard formulation, the f(T) field equations are not invariant under local Lorentz transformations, and thus the theory does not inherit the causal structure of special relativity. Actually, even locally violation of causality can occur in this formulation of f(T) gravity. A locally Lorentz covariant f(T) gravity theory has been devised recently, and this local causality problem seems to have been overcome. The non-locality question, however, is left open. If gravitation is to be described by this covariant f(T) gravity theory there are a number of issues that ought to be examined in its context, including the question as to whether its field equations allow homogeneous Goedel-type solutions, which necessarily leads to violation of causality on non-local scale. Here, to look into the potentialities and difficulties of the covariant f(T) theories, we examine whether they admit Goedel-type solutions. We take a combination of a perfect fluid with electromagnetic plus a scalar field as source, and determine a general Goedel-type solution, which contains special solutions in which the essential parameter of Goedel-type geometries, m{sup 2}, defines any class of homogeneous Goedel-type geometries. We show that solutions of the trigonometric and linear classes (m{sup 2} < 0 and m = 0) are permitted only for the combined matter sources with an electromagnetic field matter component. We extended to the context of covariant f(T) gravity a theorem which ensures that any perfect-fluid homogeneous Goedel-type solution defines the same set of Goedel tetrads h{sub A}{sup μ} up to a Lorentz transformation. We also showed that the single massless scalar field generates Goedel-type solution with no closed time-like curves. Even though the covariant f(T) gravity restores Lorentz covariance of the field equations and the local validity of the causality principle, the bare existence of the Goedel-type solutions makes apparent that the covariant formulation of f(T) gravity

Composição florística da regeneração natural de espécies arbóreas ao longo de oito anosem um fragmento de floresta estacional semidecidual, em Viçosa, MG Floristic composition of natural regeneration of tree species in a mountain seasonal semideciduous florest fragment over an eigth year period, in Viçosa, MG, Brazil

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Pedro Higuchi

2006-12-01

Full Text Available A florística da regeneração natural foi estudada em 10 locais, com seis sub-parcelas em cada local, em 1992, 1995 e 2000, em fragmento de Floresta Estacional Semidecidual Montana, em Viçosa, MG. A amostragem da classe 1 de tamanho de planta (até 1 m de altura, classe 2 (1-3 m de altura e classe 3 (>3 m de altura e The floristic composition of the natural regeneration in a secondary Seasonal Semideciduous Forest fragment in the Atlantic Forest domain, Southeastern Brazil, was studied in the years 1992, 1995 and 2000. The sampling unit sizes were 0.5x10m, 0.5x20m and 1x20m, respectively, for plant size class 1 (height up to 1 m, class 2 (height from 1 to 3 m and class 3 (height > 3m and DBH < 5cm. A total of 4,149 individuals were sampled over the inventory period, comprising 42 families and 160 species, being 11.7 % pioneer, 62.1 % early secondary, and 26.2 % late secondary species. Family number did not change and number of species increased with time. Fabaceae, Myrtaceae, Rubiaceae and Lauraceae were the predominant families. Species ingrowth was higher than mortality. Shannon-Weaver diversity index was significantly lower (P < 0.05 only for the plant size class 1 as compared to the other size classes, in 1992, and it increased significantly from 3.45 (average of all plant size classes, in 1992, to 3.67 and 3.64 in 1995 and 2000, respectively. The Pielou equability index per inventory date varied from 0.71 to 0.74, and it was 0.71; 0. 79 and 0.82 for the size classes 1, 2 and 3, respectively. Overall, the results showed that monitoring the natural regeneration over an age sequence is important to understand the dynamics of the secondary forest fragments.

The Bradford Hill considerations on causality: a counterfactual perspective

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Höfler Michael

2005-11-01

Full Text Available Abstract Bradford Hill's considerations published in 1965 had an enormous influence on attempts to separate causal from non-causal explanations of observed associations. These considerations were often applied as a checklist of criteria, although they were by no means intended to be used in this way by Hill himself. Hill, however, avoided defining explicitly what he meant by "causal effect". This paper provides a fresh point of view on Hill's considerations from the perspective of counterfactual causality. I argue that counterfactual arguments strongly contribute to the question of when to apply the Hill considerations. Some of the considerations, however, involve many counterfactuals in a broader causal system, and their heuristic value decreases as the complexity of a system increases; the danger of misapplying them can be high. The impacts of these insights for study design and data analysis are discussed. The key analysis tool to assess the applicability of Hill's considerations is multiple bias modelling (Bayesian methods and Monte Carlo sensitivity analysis; these methods should be used much more frequently.

Canales de distribución y estrategias de comercialización para la flor colombiana en los Estados Unidos: un marco conceptual

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LUIS FELIPE SALOM SERNA

2012-01-01

Full Text Available El floricultor colombiano no puede desconocer los cambios en tendencias de consumo ni la consolidación del canal retail en su mercado principal, USA. El cuál generará un alto impacto en las características del negocio y el papel de los jugadores en la cadena de suministros. El objetivo de este estudio exploratorio utilizando casos múltiples, es presentar un marco de oportunidades para fortalecer la comercialización de la flor y estructurar canales de distribución acordes a las necesidades del consumidor norteamericano y a los cambios en los hábitos de compra. Las conclusiones, proponen las acciones a emprender por las empresas floricultoras estudiadas a fin de incrementar su competitividad y resolver su dilema actual: contraer oferta para mejorar el precio de venta o incrementar demanda.

Canales de distribución y estrategias de comercialización para la flor colombiana en los Estados Unidos: un marco conceptual

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Luis Felipe Salom Serna

2012-07-01

Full Text Available El floricultor colombiano no puede desconocer los cambios en tendencias de consumo ni la consolidación del canal retail en su mercado principal, usa.El cuál generará un alto impacto en las características del negocio y el papel de los jugadores en la cadena de suministros. El objetivo de este estudio exploratorio utilizando casos múltiples, es presentar un marco de oportunidades para fortalecer la comercialización de la flor y estructurar canales de distribución acordes a las necesidades del consumidor norteamericano y a los cambios en los hábitos de compra. Las conclusiones, proponen las acciones a emprender por las empresas floriculturas estudiadas a fin de incrementar su competitividad y resolver su dilema actual: contraer oferta para mejorar el precio de venta o incrementar demanda.

Temporal and Statistical Information in Causal Structure Learning

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McCormack, Teresa; Frosch, Caren; Patrick, Fiona; Lagnado, David

2015-01-01

Three experiments examined children's and adults' abilities to use statistical and temporal information to distinguish between common cause and causal chain structures. In Experiment 1, participants were provided with conditional probability information and/or temporal information and asked to infer the causal structure of a 3-variable mechanical…

Ends, Principles, and Causal Explanation in Educational Justice

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Dum, Jenn

2017-01-01

Many principles characterize educational justice in terms of the relationship between educational inputs, outputs and distributive standards. Such principles depend upon the "causal pathway view" of education. It is implicit in this view that the causally effective aspects of education can be understood as separate from the normative…

The power of possibility: causal learning, counterfactual reasoning, and pretend play.

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Buchsbaum, Daphna; Bridgers, Sophie; Skolnick Weisberg, Deena; Gopnik, Alison

2012-08-05

We argue for a theoretical link between the development of an extended period of immaturity in human evolution and the emergence of powerful and wide-ranging causal learning mechanisms, specifically the use of causal models and Bayesian learning. We suggest that exploratory childhood learning, childhood play in particular, and causal cognition are closely connected. We report an empirical study demonstrating one such connection--a link between pretend play and counterfactual causal reasoning. Preschool children given new information about a causal system made very similar inferences both when they considered counterfactuals about the system and when they engaged in pretend play about it. Counterfactual cognition and causally coherent pretence were also significantly correlated even when age, general cognitive development and executive function were controlled for. These findings link a distinctive human form of childhood play and an equally distinctive human form of causal inference. We speculate that, during human evolution, computations that were initially reserved for solving particularly important ecological problems came to be used much more widely and extensively during the long period of protected immaturity.

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....

Occupational safety management: the role of causal attribution.

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Gyekye, Seth Ayim

2010-12-01

The paper addresses the causal attribution theory, an old and well-established theme in social psychology which denotes the everyday, commonsense explanations that people use to explain events and the world around them. The attribution paradigm is considered one of the most appropriate analytical tools for exploratory and descriptive studies in social psychology and organizational literature. It affords the possibility of describing accident processes as objectively as possible and with as much detail as possible. Causal explanations are vital to the formal analysis of workplace hazards and accidents, as they determine how organizations act to prevent accident recurrence. Accordingly, they are regarded as fundamental and prerequisite elements for safety management policies. The paper focuses primarily on the role of causal attributions in occupational and industrial accident analyses and implementation of safety interventions. It thus serves as a review of the contribution of attribution theory to occupational and industrial accidents. It comprises six sections. The first section presents an introduction to the classic attribution theories, and the second an account of the various ways in which the attribution paradigm has been applied in organizational settings. The third and fourth sections review the literature on causal attributions and demographic and organizational variables respectively. The sources of attributional biases in social psychology and how they manifest and are identified in the causal explanations for industrial and occupational accidents are treated in the fifth section. Finally, conclusion and recommendations are presented. The recommendations are particularly important for the reduction of workplace accidents and associated costs. The paper touches on the need for unbiased causal analyses, belief in the preventability of accidents, and the imperative role of management in occupational safety management.

THE CAUSAL ANALYSIS / DIAGNOSIS DECISION ...

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CADDIS is an on-line decision support system that helps investigators in the regions, states and tribes find, access, organize, use and share information to produce causal evaluations in aquatic systems. It is based on the US EPA's Stressor Identification process which is a formal method for identifying causes of impairments in aquatic systems. CADDIS 2007 increases access to relevant information useful for causal analysis and provides methods and tools that practitioners can use to analyze their own data. The new Candidate Cause section provides overviews of commonly encountered causes of impairments to aquatic systems: metals, sediments, nutrients, flow alteration, temperature, ionic strength, and low dissolved oxygen. CADDIS includes new Conceptual Models that illustrate the relationships from sources to stressors to biological effects. An Interactive Conceptual Model for phosphorus links the diagram with supporting literature citations. The new Analyzing Data section helps practitioners analyze their data sets and interpret and use those results as evidence within the USEPA causal assessment process. Downloadable tools include a graphical user interface statistical package (CADStat), and programs for use with the freeware R statistical package, and a Microsoft Excel template. These tools can be used to quantify associations between causes and biological impairments using innovative methods such as species-sensitivity distributions, biological inferenc

Obesity and infection: reciprocal causality.

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Hainer, V; Zamrazilová, H; Kunešová, M; Bendlová, B; Aldhoon-Hainerová, I

2015-01-01

Associations between different infectious agents and obesity have been reported in humans for over thirty years. In many cases, as in nosocomial infections, this relationship reflects the greater susceptibility of obese individuals to infection due to impaired immunity. In such cases, the infection is not related to obesity as a causal factor but represents a complication of obesity. In contrast, several infections have been suggested as potential causal factors in human obesity. However, evidence of a causal linkage to human obesity has only been provided for adenovirus 36 (Adv36). This virus activates lipogenic and proinflammatory pathways in adipose tissue, improves insulin sensitivity, lipid profile and hepatic steatosis. The E4orf1 gene of Adv36 exerts insulin senzitizing effects, but is devoid of its pro-inflammatory modalities. The development of a vaccine to prevent Adv36-induced obesity or the use of E4orf1 as a ligand for novel antidiabetic drugs could open new horizons in the prophylaxis and treatment of obesity and diabetes. More experimental and clinical studies are needed to elucidate the mutual relations between infection and obesity, identify additional infectious agents causing human obesity, as well as define the conditions that predispose obese individuals to specific infections.

Untangling the causal relationship between tax burden distribution and economic growth in 23 OECD countries: Fresh evidence from linear and non-linear Granger causality

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Sami Saafi

2017-12-01

Full Text Available The aim of the paper is to investigate the linear and nonlinear causality between a set of alternative tax burden ratios and economic growth in 23 OECD countries. To that end, the linear causality approach of Toda– Yamamoto (1995 and the nonparametric causality method of Kyrtsou and Labys (2006 are applied to annual data spanning from 1970 to 2014. Results obtained from the nonlinear causality test tend to reject the neutrality hypothesis for the tax structure–growth relationship in 19 of the 23 OECD countries. In the majority of the countries under investigation, the evidence is in line with the growth hypothesis where causality running from economic growth to tax burden ratios was detected in Australia, Denmark, Finland, Japan, New Zealand, and Norway. The opposite causality running from tax structure to economic growth was found in Germany, Netherlands, Portugal, and Sweden. In contrast, the neutrality hypothesis was supported in Austria, Italy, Luxembourg, and the USA, whereas the feedback hypothesis was supported in Turkey and the UK. Additional robustness checks show that when the signs of variations are taken into account, there is an asymmetric causality running from positive tax burden shocks to positive per capita GDP shocks for Belgium, France, and Turkey. Overall, our findings suggest that policy implications of the tax structure-economic growth relationships should be interpreted with caution, taking into account the test-dependent and country-specific results.

Diversidad florística arbórea y su relación con el suelo en un bosque pluvial tropical del chocó biogeográfico

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Harley Quinto Mosquera

2014-12-01

Full Text Available El objetivo del presente estudio fue determinar la composición y diversidad florística arbórea a escala local en un bosque del Chocó biogeográfico, una de las regiones más lluviosas del mundo, y su relación con las características del sitio. Se emplearon dos parcelas de una hectárea, en las cuales se determinó la composición y diversidad de árboles con DAP > 10 cm y se relacionaron con los nutrientes del suelo, la topografíay el espacio. No se presentaron diferencias significativas entre las parcelas para las variables estructurales y de diversidad estudiadas, con valores de abundancia de 640 y 716 individuos/ha yde riqueza de 174 y 223 especies/ha.Nuestros resultados soportan la hipótesis de hiperdominancia de unos pocos grupos biológicos en los bosques húmedos tropicales. Ladiversidad arbórea a escala local se relacionó significativamente con algunas condiciones edáficas.Se presentó asociación positiva de la diversidad con el aluminio del suelo, y negativa con la topografía.No obstante, solamente un 37% de la variación en la composición florística fue explicada por las variables espaciales y ambientales (topográficas y edáficas. Por ello, aparentemente la distribución de las especies a escala local parece estar gobernada principalmente por procesos aleatorios o biológicos (como la limitación en dispersión, conforme lo propone la teoría neutral. El papel de las adaptaciones específicas al hábitat (teoría del nicho pareciera ser limitado.

Florística, fitossociologia e diversidade da vegetação arbórea nas matas de galeria do Parque Nacional de Sete Cidades (PNSC, Piauí, Brasil Floristics, phytosociology and diversity of tree vegetation in gallery forests of Sete Cidades National Park (PNSC, Piauí, Brazil

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Mariana de Queiroz Matos

2010-06-01

Full Text Available O presente estudo foi realizado nas matas de galeria do Parque Nacional de Sete Cidades (PNSC, área prioritária para conservação do Cerrado. Teve como objetivos estudar a composição florística, fitossociologia e diversidade das matas de galeria que se distribuem ao longo dos cursos d’água localizados no PNSC e avaliar a similaridade florística destas com outras matas em diversas localidades do Cerrado. A vegetação arbórea (DAP > 5 cm foi amostrada em quatro trechos de mata ao longo do Parque, cada um subdividido em transectos (equidistantes em 50 m e perpendiculares ao leito do córrego principal, onde sistematicamente foram alocadas 56 parcelas de 10 x 10 m (0,01 ha. Foram encontradas 75 espécies arbóreas pertencentes a 64 gêneros e 30 famílias. A família de maior riqueza na amostragem foi Fabaceae (14 espécies. Virola surinamensis foi a espécie de maior valor de importância (VI na amostragem.Estimou-se uma densidade absoluta de 1.146,43 ind ha-1 e área basal de 26,55 m² ha-1. A diversidade alfa, obtida por meio do Índice de Shannon (H’, foi de 3,53 e a equabilidade de Pielou (J’ de 0,82. A diversidade beta entre o Parque e outras localidades do bioma Cerrado foi elevada. As matas de galeria do PNSC apresentam alta riqueza e diversidade florística, compartilham espécies com matas em localidades diversas e contêm espécies típicas a outros biomas, evidenciando a localização geográfica do Parque em "área de tensão ecológica".This study was undertaken in the gallery forests of Sete Cidades National Park (PNSC, a priority area for conservation of the Cerrado. The objective was to study the floristic composition, phytosociology and diversity of the gallery forests distributed along the river courses located in PNSC and also evaluate floristic similarity between these forests and others in the Cerrado biome. The tree vegetation (DAP > 5 cm was sampled in four sections of forest in the Park, each subdivided into

Causal Learning in Gambling Disorder: Beyond the Illusion of Control.

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Perales, José C; Navas, Juan F; Ruiz de Lara, Cristian M; Maldonado, Antonio; Catena, Andrés

2017-06-01

Causal learning is the ability to progressively incorporate raw information about dependencies between events, or between one's behavior and its outcomes, into beliefs of the causal structure of the world. In spite of the fact that some cognitive biases in gambling disorder can be described as alterations of causal learning involving gambling-relevant cues, behaviors, and outcomes, general causal learning mechanisms in gamblers have not been systematically investigated. In the present study, we compared gambling disorder patients against controls in an instrumental causal learning task. Evidence of illusion of control, namely, overestimation of the relationship between one's behavior and an uncorrelated outcome, showed up only in gamblers with strong current symptoms. Interestingly, this effect was part of a more complex pattern, in which gambling disorder patients manifested a poorer ability to discriminate between null and positive contingencies. Additionally, anomalies were related to gambling severity and current gambling disorder symptoms. Gambling-related biases, as measured by a standard psychometric tool, correlated with performance in the causal learning task, but not in the expected direction. Indeed, performance of gamblers with stronger biases tended to resemble the one of controls, which could imply that anomalies of causal learning processes play a role in gambling disorder, but do not seem to underlie gambling-specific biases, at least in a simple, direct way.

The discourse of causal explanations in school science

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Slater, Tammy Jayne Anne

Researchers and educators working from a systemic functional linguistic perspective have provided a body of work on science discourse which offers an excellent starting point for examining the linguistic aspects of the development of causal discourse in school science, discourse which Derewianka (1995) claimed is critical to success in secondary school. No work has yet described the development of causal language by identifying the linguistic features present in oral discourse or by comparing the causal discourse of native and non-native (ESL) speakers of English. The current research responds to this gap by examining the oral discourse collected from ESL and non-ESL students at the primary and high school grades. Specifically, it asks the following questions: (1) How do the teachers and students in these four contexts develop causal explanations and their relevant taxonomies through classroom interactions? (2) What are the causal discourse features being used by the students in these four contexts to construct oral causal explanations? The findings of the social practice analysis showed that the teachers in the four contexts differed in their approaches to teaching, with the primary school mainstream teacher focusing largely on the hands-on practice , the primary school ESL teacher moving from practice to theory, the high school mainstream teacher moving from theory to practice, and the high school ESL teacher relying primarily on theory. The findings from the quantitative, small corpus approach suggest that the developmental path of cause which has been identified in the writing of experts shows up not only in written texts but also in the oral texts which learners construct. Moreover, this move appears when the discourse of high school ESL and non-ESL students is compared, suggesting a developmental progression in the acquisition of these features by these students. The findings also reveal that the knowledge constructed, as shown by the concept maps created

Composição lignocelulósica e isótopica da vegetação e da matéria orgânica do solo de uma turfeira tropical: I - composição florística, fitomassa e acúmulo de carbono

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Vinicius Evangelista Silva

2013-02-01

Full Text Available A matéria orgânica do solo (MOS é um dos grandes reservatórios de carbono (C da Terra e constitui um dos principais componentes do ciclo do C. Turfeiras, ambientes acumuladores de MOS, são produto da decomposição de vegetais, que se desenvolvem e se acumulam em ambientes saturados com água, sendo o estádio inicial da sequência de carbonificação. A fitomassa participa de forma marcante no ciclo global do C, armazenando em torno de 85 % de todo o C terrestre acima do solo. O tecido vegetal é composto principalmente por lignina, celulose e hemicelulose, constituindo até 85 % da biomassa seca. As plantas discriminam C de forma diferenciada, em razão de seu ciclo fotossintético (C3, C4 e CAM. As turfeiras da Serra do Espinhaço Meridional (SdEM-MG são colonizadas por vegetação de Campo Limpo Úmido (CLU e de Floresta Estacional Semidecidual (FES, onde ocorrem espécies dos ciclos fotossintéticos C3 e C4. Este trabalho objetivou avaliar a contribuição dessas duas fitofisionomias para o acúmulo de MOS, por meio da avaliação da fitomassa e da composição lignocelulósica e isotópica da vegetação e da MOS. A turfeira estudada localiza-se na SdEM e ocupa 81,75 ha. Para a estimativa da fitomassa do CLU e da FES, foram marcadas três parcelas de 0,5 x 0,5 m em cada fitofisionomia, onde todos os indivíduos da parcela foram cortados e armazenados. Para as análises isotópicas e lignocelulósicas da vegetação, identificaram-se as espécies dominantes em cada fitofisionomia. Amostras de solo foram coletadas em três locais representativos sob cada fitofisionomia, a cada 5 cm de profundidade, até 50 cm. Foram extraídas a celulose e a lignina das folhas das 15 espécies dominantes e das 60 amostras de turfeira para quantificação e determinação dos valores de δ13C e δ15N. Para datação da MOS, o 14C foi determinado em três profundidades, sob o CLU e a FES. A produção da fitomassa da FES foi muito superior à produ

Nonparametric Identification of Causal Effects under Temporal Dependence

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Dafoe, Allan

2018-01-01

Social scientists routinely address temporal dependence by adopting a simple technical fix. However, the correct identification strategy for a causal effect depends on causal assumptions. These need to be explicated and justified; almost no studies do so. This article addresses this shortcoming by offering a precise general statement of the…

On Storks and Babies: Correlation, Causality and Field Experiments

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Lambrecht Anja

2016-11-01

Full Text Available The explosion of available data has created much excitement among marketing practitioners about their ability to better understand the impact of marketing investments. Big data allows for detecting patterns and often it seems plausible to interpret them as causal. While it is quite obvious that storks do not bring babies, marketing relationships are usually less clear. Apparent “causalities” often fail to hold up under examination. If marketers want to be sure not to walk into a causality trap, they need to conduct field experiments to detect true causal relationships. In the present digital environment, experiments are easier than ever to execute. However, they need to be prepared and interpreted with great care in order to deliver meaningful and genuinely causal results that help improve marketing decisions.

Implications of causality for quantum biology - I: topology change

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Scofield, D. F.; Collins, T. C.

2018-06-01

A framework for describing the causal, topology changing, evolution of interacting biomolecules is developed. The quantum dynamical manifold equations (QDMEs) derived from this framework can be related to the causality restrictions implied by a finite speed of light and to Planck's constant to set a transition frequency scale. The QDMEs imply conserved stress-energy, angular-momentum and Noether currents. The functional whose extremisation leads to this result provides a causal, time-dependent, non-equilibrium generalisation of the Hohenberg-Kohn theorem. The system of dynamical equations derived from this functional and the currents J derived from the QDMEs are shown to be causal and consistent with the first and second laws of thermodynamics. This has the potential of allowing living systems to be quantum mechanically distinguished from non-living ones.

On the Temporal Causal Relationship Between Macroeconomic Variables

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Srinivasan Palamalai

2014-02-01

Full Text Available The present study examines the dynamic interactions among macroeconomic variables such as real output, prices, money supply, interest rate (IR, and exchange rate (EXR in India during the pre-economic crisis and economic crisis periods, using the autoregressive distributed lag (ARDL bounds test for cointegration, Johansen and Juselius multivariate cointegration test, Granger causality/Block exogeneity Wald test based on Vector Error Correction Model, variance decomposition analysis and impulse response functions. The empirical results reveal a stronger long-run bilateral relationship between real output, price level, IR, and EXR during the pre-crisis sample period. Moreover, the empirical results confirm a unidirectional short-run causality running from price level to EXR, IR to price level, and real output to money supply during the pre-crisis period. Also, it is evident from the test results that there exist short-run bidirectional relationships running between real output and EXR, price level and IR, and IR and EXR in the pre-crisis era, respectively. Most importantly, long-run bidirectional causality is found between real output, EXR, and IR during the economic crisis period. And the study results indicate short-run bidirectional causality between money supply and EXR, IR and price level, and IR and output in India during the crisis era. Also, a short-run unidirectional causality runs from prices to real output in the crisis period.

Explaining through causal mechanisms

NARCIS (Netherlands)

Biesbroek, Robbert; Dupuis, Johann; Wellstead, Adam

2017-01-01

This paper synthesizes and builds on recent critiques of the resilience literature; namely that the field has largely been unsuccessful in capturing the complexity of governance processes, in particular cause–effects relationships. We demonstrate that absence of a causal model is reflected in the

They Work Together to Roar: Kindergartners' Understanding of an Interactive Causal Task

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Solis, S. Lynneth; Grotzer, Tina A.

2016-01-01

The aim of this study was to investigate kindergartners' exploration of interactive causality during their play with a pair of toy sound blocks. Interactive causality refers to a type of causal pattern in which two entities interact to produce a causal force, as in particle attraction and symbiotic relationships. Despite being prevalent in nature,…

Respuesta de la composición florística y la diversidad biológica de pastizales a las estrategias de manejo en una dehesa de la Sierra de Guadarrama, Madrid

OpenAIRE

Martínez, T.; Urquia, J.; Tejerina, J.I.; Miguel, J.M. de

2012-01-01

Ponencia presentada a la 51 Reunión Científica de la SEEP celebrada en la Escuela Superior de Ingenieros Agrónomos de la Universidad Pública de Navarra entre el 14 y el 18 de mayo de 2012. Este estudio tipifica y caracteriza las comunidades de pastizal en función de su composición florística, riqueza y diversidad biológica en un sistema silvopastoral de dehesa situado en la Sierra de Guadarrama (Finca de Riosequillo, Buitrago de Lozoya, Madrid). Se identifican las tendencias principales de...

On the conceptual distinction of general causality orientations

DEFF Research Database (Denmark)

Olesen, Martin Hammershøj

electronic questionnaires of dispositional personality traits (NEO-FFI) and general causality orientations (GCOS). Proposed separate latent models and alternative shared latent models of the underlying individual differences constructs had been developed in a previous exploratory study (Olesen, Thomsen......, that is general causality orientations can be understood as characteristic adaptations of dispositional traits....

An Information Processing Approach to Children's Causal Reasoning.

Science.gov (United States)

Siegler, Robert S.

This paper questions evidence for the thesis that causal reasoning of older children is more logical than that of younger ones, and describes two experiments which attempted to determine (1) whether there are true developmental differences in causal reasoning, and (2) what explanations for developmental differences can be supported. In the first…

Weighting-Based Sensitivity Analysis in Causal Mediation Studies

Science.gov (United States)

Hong, Guanglei; Qin, Xu; Yang, Fan

2018-01-01

Through a sensitivity analysis, the analyst attempts to determine whether a conclusion of causal inference could be easily reversed by a plausible violation of an identification assumption. Analytic conclusions that are harder to alter by such a violation are expected to add a higher value to scientific knowledge about causality. This article…

Causality analysis in business performance measurement system using system dynamics methodology

Science.gov (United States)

Yusof, Zainuridah; Yusoff, Wan Fadzilah Wan; Maarof, Faridah

2014-07-01

One of the main components of the Balanced Scorecard (BSC) that differentiates it from any other performance measurement system (PMS) is the Strategy Map with its unidirectional causality feature. Despite its apparent popularity, criticisms on the causality have been rigorously discussed by earlier researchers. In seeking empirical evidence of causality, propositions based on the service profit chain theory were developed and tested using the econometrics analysis, Granger causality test on the 45 data points. However, the insufficiency of well-established causality models was found as only 40% of the causal linkages were supported by the data. Expert knowledge was suggested to be used in the situations of insufficiency of historical data. The Delphi method was selected and conducted in obtaining the consensus of the causality existence among the 15 selected expert persons by utilizing 3 rounds of questionnaires. Study revealed that only 20% of the propositions were not supported. The existences of bidirectional causality which demonstrate significant dynamic environmental complexity through interaction among measures were obtained from both methods. With that, a computer modeling and simulation using System Dynamics (SD) methodology was develop as an experimental platform to identify how policies impacting the business performance in such environments. The reproduction, sensitivity and extreme condition tests were conducted onto developed SD model to ensure their capability in mimic the reality, robustness and validity for causality analysis platform. This study applied a theoretical service management model within the BSC domain to a practical situation using SD methodology where very limited work has been done.

Information–theoretic implications of quantum causal structures

DEFF Research Database (Denmark)

Chaves, Rafael; Majenz, Christian; Gross, David

2015-01-01

. However, no systematic method is known for treating such problems in a way that generalizes to quantum systems. Here, we describe a general algorithm for computing information–theoretic constraints on the correlations that can arise from a given causal structure, where we allow for quantum systems as well...... as classical random variables. The general technique is applied to two relevant cases: first, we show that the principle of information causality appears naturally in our framework and go on to generalize and strengthen it. Second, we derive bounds on the correlations that can occur in a networked architecture......It is a relatively new insight of classical statistics that empirical data can contain information about causation rather than mere correlation. First algorithms have been proposed that are capable of testing whether a presumed causal relationship is compatible with an observed distribution...

Comparison of a noncausal with a causal relativistic wave-packet evolution

International Nuclear Information System (INIS)

Castro, A.N. de; Jabs, A.

1991-01-01

In order to study causality violation in more detail we contrast the Klein-Gordon wave packet of Rosenstein und Usher with the Dirac wave packet of Bakke and Wergeland. Both packets are initially localized with exponentially bounded tails but just outside the condition of the general Hegerfeldt theorem for causality violation. It turns out that the wave packet of Bakke and Wergeland exhibits all the features investigated by Rosenstein and Usher, except that it never violates relativistic causality. Thus none of those features, in particular the back- and forerunners emerging from the light cone, can be held responsible for causality violation, and the Ruijsenaars integral is not necessarily a measure of the amount of causality violation. (orig.)

Variación florística de especies arbóreas a escala local en un bosque de tierra firme en la Amazonia colombiana Floristic variation of canopy tree species at a local scale on tierra firme forests in colombian Amazonia

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Juan Sebastian Barreto Silva

2010-03-01

Full Text Available El presente estudio se llevó a cabo en cinco hectáreas de una parcela permanente establecida en el Parque Nacional Amacayacu, Amazonia colombiana. En éste, se evaluó el efecto de la variación ambiental y la configuración espacial sobre los patrones florísticos de las especies arbóreas (DAP>10 cm a escala local en un bosque de tierra firme. Se estudió la variación florística y ambiental en cuadrantes de 20x20 m. Adicionalmente, se consideraron diferentes categorías de abundancia (total, alta, media y baja. Se utilizó el Análisis de Correspondencia Linealizado y el Análisis de Correspondencia Canónica, seguido de una partición de la variación, para cuantificar la magnitud a la cual el ambiente y la limitación en dispersión determinan la variación florística. La fracción espacial, representando procesos de autocorrelación como la limitación en dispersión, se analizó mediante dos métodos: Asumiendo un polinomio de tercer grado y por el método de Coordenadas Principales de Matrices Vecinas (PCNM. La diversidad beta de la parcela fue baja. El PCNM aparece como el método de análisis más apropiado para estudios a esta escala. Las diferencias florísticas explicadas a lo largo de la parcela de 5-ha fueron principalmente asociadas con procesos biológicos como la limitación en dispersión. La mayor parte de la variación florística, no obstante, no fue explicada por las variables ambientales o espaciales consideradas. En conclusión, estos resultados sugieren que procesos aleatorios son determinantes esenciales de la variación espacial de las especies arbóreas a escala local en tierra firme en los bosques en el Parque Nacional Amacayacu.This study was carried out in a 5-ha permanent plot established in the Amacayacu National Park, Colombian Amazonia. We assessed the extent at which floristic patterns of tree species were determined by either the environmental variation or the spatial configuration in tierra firme

Granger Causality and Transfer Entropy Are Equivalent for Gaussian Variables

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Barnett, Lionel; Barrett, Adam B.; Seth, Anil K.

2009-12-01

Granger causality is a statistical notion of causal influence based on prediction via vector autoregression. Developed originally in the field of econometrics, it has since found application in a broader arena, particularly in neuroscience. More recently transfer entropy, an information-theoretic measure of time-directed information transfer between jointly dependent processes, has gained traction in a similarly wide field. While it has been recognized that the two concepts must be related, the exact relationship has until now not been formally described. Here we show that for Gaussian variables, Granger causality and transfer entropy are entirely equivalent, thus bridging autoregressive and information-theoretic approaches to data-driven causal inference.

Efficient nonparametric estimation of causal mediation effects

OpenAIRE

Chan, K. C. G.; Imai, K.; Yam, S. C. P.; Zhang, Z.

2016-01-01

An essential goal of program evaluation and scientific research is the investigation of causal mechanisms. Over the past several decades, causal mediation analysis has been used in medical and social sciences to decompose the treatment effect into the natural direct and indirect effects. However, all of the existing mediation analysis methods rely on parametric modeling assumptions in one way or another, typically requiring researchers to specify multiple regression models involving the treat...

The Continuum Limit of Causal Fermion Systems

OpenAIRE

Finster, Felix

2016-01-01

This monograph introduces the basic concepts of the theory of causal fermion systems, a recent approach to the description of fundamental physics. The theory yields quantum mechanics, general relativity and quantum field theory as limiting cases and is therefore a candidate for a unified physical theory. From the mathematical perspective, causal fermion systems provide a general framework for describing and analyzing non-smooth geometries and "quantum geometries." The dynamics is described by...

Papilionoideae (Leguminosae arbóreas e lianas na estação de pesquisa, treinamento e educação ambiental (EPTEA, Mata do Paraíso, Viçosa, Zona da Mata Mineira Trees and lianes of the papilionoideae (Leguminosae in the research, training and environmental education station (EPTEA, Mata do Paraíso, Viçosa, Zona da Mata Mineira

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Izabella Martins da Costa Rodrigues

2007-01-01

Full Text Available Este trabalho consiste em um levantamento florístico das árvores e lianas pertencentes à Papilionoideae da Mata do Paraíso, importante fragmento de Floresta Estacional Semidecidual Submontana, no Município de Viçosa, Zona da Mata mineira. A pesquisa de campo foi realizada por meio de visitas à área de estudo, no período de julho/2004 a agosto/2005. Foram reconhecidos 12 táxons infra-específicos pertencentes a oito gêneros, sendo Machaerium Pers. (4 spp. e Dalbergia L. f. (2 spp. os mais representativos. São apresentados chaves de identificação, descrições, ilustrações e comentários sobre os táxons analisados. Dalbergia nigra (Vell. Allemão ex Benth., espécie vulnerável, e Ormosia vicosana Rudd, endêmica da região, foram encontradas na EPTEA.This work is a floristic survey of trees and lianas of the Papilionoideae in the Mata do Paraíso, an important fragment of Submontane Semideciduous Seasonal Forest, in Viçosa, Zona da Mata Mineira. The fieldwork was carried out through visits to the studied area, from July/2004 to August/2005. Twelve taxa represented by eight genera were recorded. Machaerium Pers. (4spp. and Dalbergia L. f. (2 spp. were the most representatives. Identification keys, descriptions and illustrations are presented for the analyzed taxa. Dalbergia nigra (Vell. Allemão ex Benth., vulnerable species and, Ormosia vicosana Rudd, endemic for the region were found at EPTEA.

QUALIDADE PÓS-COLHEITA DA MORINGA (MORINGA OLEIFERA LAM UTILIZADA NA FORMA IN NATURA E SECA

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Menezes dos Passos

2013-03-01

Full Text Available A Moringa Oleifera Lam é uma planta ornamental e medicinal e possui a característica de adaptar-se a climas áridos e solos pobres em nutrientes. É um vegetal da família Moringaceae, originária do norte da Índia. Este trabalho teve como objetivo realizar a caracterização físico-química de partes constituintes da planta: folha, flor, semente e vagem utilizadas na forma in natura e seca. O experimento foi conduzido no Laboratório de Tecnologias Alternativas em São Cristóvão - SE. Posteriormente, as amostras de folhas, flores, sementes e vagens utilizadas neste trabalho foram coletadas e separadas em dois lotes, sendo um lote com as amostras que seriam analisadas in natura e o outro com amostras secas em secador solar. Foram realizadas as seguintes análises: atividade de água, acidez titulável, umidade, cinzas, lipídeos, proteínas, carboidratos, vitamina C, carotenoides,fibra total e alimentícia.Os dados obtidos foram submetidos à análise de variância (ANOVA e teste de Tukey para comparação de médias ao nível de significância de 5%. Foi possível observar que para as análises de acidez, cinzas, lipídeos, proteínas e carboidratos, os resultados encontrados foram maiores nas partes secas quando comparado ao in natura. Entretanto, os valores para atividade de água, umidade, vitamina C e pH foram superiores nas análises in natura quando comparadas às amostras secas. Para os resultados de carotenoides, obtiveram-se variações em ambas as partes. Portanto, a Moringa apresenta-se como um vegetal de excelentes propriedades nutricionais e funcionais.

On causal nonrelativistic classical electrodynamics

International Nuclear Information System (INIS)

Goedecke, G.H.

1984-01-01

The differential-difference (DD) motion equations of the causal nonrelativistic classical electrodynamics developed by the author in 1975 are shown to possess only nonrunaway, causal solutions with no discontinuities in particle velocity or position. As an example, the DD equation solution for the problem of an electromagnetic shock incident on an initially stationary charged particle is contrasted with the standard Abraham-Lorentz equation solution. The general Cauchy problem for these DD motion equations is discussed. In general, in order to uniquely determine a solution, the initial data must be more detailed than the standard Cauchy data of initial position and velocity. Conditions are given under which the standard Cauchy data will determine the DD equation solutions to sufficient practical accuracy

Corporate Governance and Financial Performance Nexus: Any Bidirectional Causality?

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Alley Ibrahim S.

2016-06-01

Full Text Available Most studies on corporate governance recognize endogeneity in the nexus between corporate governance and financial performance. Little attention has, however, been paid to the direction of causality between the two phenomena, and hence the Vector Error Correction (VEC model, which allows for endogenous determination of the direction of causality, has not been widely employed. This study fills that gap by estimating the nexus and the direction of causality using the VEC model to analyze panel data on selected listed firms in Nigeria. The results agree with the findings of most previous studies that corporate governance significantly affects financial performance. Board skills, board composition and management skills enhanced financial performance indicators – return on equity (ROE, return on asset (ROA and net profit margin (NPM; in many occasions, significantly. Board size and audit committee size did not, and can actually undermine financial performance. More importantly, financial performance did not significantly affect corporate governance. On the basis of the lag structure of the VEC model, this study affirms unidirectional causality in the nexus, running from corporate governance to financial performance, nullifying the hypothesis of bidirectional causality in the nexus.

Bromeliaceae da restinga da Reserva Biológica Estadual da Praia do Sul: composição, abundância e similaridade da comunidade Bromeliaceae of the Praia do Sul State Biological Reserve restinga: community composition, abundance and similarity

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André Felippe Nunes-Freitas

2006-09-01

Full Text Available A Reserva Biológica Estadual da Praia do Sul (Ilha Grande, RJ é um importante remanescente de restinga preservada do Rio de Janeiro. A vegetação das restingas não é homogênea, distribuindo-se em zonas de vegetação, e cada uma delas é caracterizada por sua topografia, fisionomia e florística distintas. Estudamos a comunidade de Bromeliaceae, analisando variações na riqueza, abundância, densidade e freqüência de ocorrência entre quatro zonas de vegetação. Nas quatro zonas, amostramos um total de 150 parcelas de 100 m² cada, onde contabilizamos as espécies e suas abundâncias, e medidas de estrutura da vegetação (altura e DAP das árvores e densidade de árvores e de arbustos do sub-bosque. Testamos diferenças entre zonas na abundância de rosetas e na estrutura da vegetação, e entre as abundâncias das espécies de bromélias através de ANOVA seguida do teste de Tukey. Encontramos 16 espécies de bromélias, com abundâncias e padrões de distribuição distintos entre as zonas, além de diferenças significativas entre as abundâncias das espécies. Os dados indicam que a elevada riqueza de espécies encontradas na RBEPS pode estar relacionada à heterogeneidade e à complexidade locais. As diferenças encontradas entre as zonas de vegetação podem ser devidas às diferenças na estrutura da vegetação de cada zona.The Praia do Sul State Biological Reserve (Ilha Grande, RJ is an important remnant of Restinga habitat in Rio de Janeiro State. Restinga vegetation is not homogeneous and it is distributed in different vegetation zones, each zone having different topography, physiognomy and flora. We analyzed ecological parameters of the bromeliad community such as richness, abundance, density, biomass and variation in species composition in four vegetation zones. We sampled 150 plots of 100 m² (10×10 m, distributed in the four vegetation zones, recording the bromeliad species and their abundance, and measuring the height

Causality between Prices and Wages: VECM Analysis for EU-27

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Adriatik Hoxha

2010-09-01

Full Text Available The literature on causality as well as the empirical evidence clearly shows that there are two opposing groups of economists, who support different hypotheses with respect to the flow of causality in the price-wage causal relationship. The first group argues that causality runs from wages to prices, whereas the second argues that effect flows from prices to wages. Nonetheless, the literature review suggeststhat there is at least some consensus in that researcher’s conclusions may be contingent on the type of data employed, applied econometric model, or even that relationship may alter with economic cycles. This paper empirically examines theprice-wage causal relationship in EU-27, by using the OLS and VECM analysis, and it also provides robust evidence in support of a bilateral causal relationship between prices and wages, both in long-run as well as in the shortrun.Prior to designing and estimating the econometric model we have performed stationarity tests for the employed price, wage and productivity variables. Additionally, we have also specified the model taking into account the lag order as well as the rank of co-integration for the co-integrated variables. Furthermore, we have also applied respective restrictions on the parameters of estimatedVECM. The evidence resulting from model robustness checks indicates that results are statistically robust. Although far from closing the issue of causality between prices and wages, this paper at least provides some fresh evidence in the case of EU-27.

Contrasting cue-density effects in causal and prediction judgments.

Science.gov (United States)

Vadillo, Miguel A; Musca, Serban C; Blanco, Fernando; Matute, Helena

2011-02-01

Many theories of contingency learning assume (either explicitly or implicitly) that predicting whether an outcome will occur should be easier than making a causal judgment. Previous research suggests that outcome predictions would depart from normative standards less often than causal judgments, which is consistent with the idea that the latter are based on more numerous and complex processes. However, only indirect evidence exists for this view. The experiment presented here specifically addresses this issue by allowing for a fair comparison of causal judgments and outcome predictions, both collected at the same stage with identical rating scales. Cue density, a parameter known to affect judgments, is manipulated in a contingency learning paradigm. The results show that, if anything, the cue-density bias is stronger in outcome predictions than in causal judgments. These results contradict key assumptions of many influential theories of contingency learning.

Análisis florístico del Parque Nacional Natural Amacayucu e Isla Mocagua, Amazonas (Colombia

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Rudas L. Agustín

1998-11-01

Full Text Available A floristic study of the Parque Nacional Natural Amacayacu and Isla Mocagua shows 1348 species, 574 genera and 128 families of vascular plants; 82% of the species are dicotyledons, 14% monocotyledons, 3.7% ferns and ca. 0.2% gymnosperms. Leguminosae, Rubiaceae, Melastomataceae, Moraceae and Annonaceae represent 33% of the dicotyledonous species, whereas Araceae, Arecaceae and Poaceae are the main monocotyledonous families. Most families are Gondwanaland elements with sorne Laurasian elements; others are of unknown origino The main habit is represented by trees and shrubs (47% and 19% of the species, 25% are vines and herbs, 9% epiphytes and hemiepiphytes, and En un estudio florístico en cinco sectores del Parque Nacional Natural Amacayacu y en la Isla Mocagua, se encontraron 1348 especies de plantas vasculares, distribuidas en 574 géneros y 128 familias; 82% de las especies corresponden a dicotiledóneas, 14% a monocotiledóneas, 3.7% a pteridófitos y ca. de 0.2% a  gimnospermas. Las principales familias fueron Leguminosae, Rubiaceae, Melastomataceae, Moraceae y Annonaceae  (dicotiledóneas, y Araceae, Arecaceae y Poaceae (monocotiledóneas. La mayoría de las familias corresponde a elementos de Gondwana con algunos elementos Laurásicos y otros sin origen asignado. El mayor número de las especies tienen hábito arbóreo o arbustivo (47% y 19% respectivamente, ca. del 25% de las especies son lianas y hierbas, 9% epífitas y hemiepífitas, mientras que las parásitas y saprófitas apenas representan < 1%. Los bosques de tierra firme presentan casi el doble de especies de arbustos, hierbas y epífitos que las planicies inundables. Algunos sectores del Parque relativamente distantes entre sí presentan una gran similaridad en cuanto a composición florística, hecho que puede atribuirse principalmente al tipo de agua (blanca, negra o mixta que los irriga. Una comparación con regiones similares en el corredor pacífico, el piedemonte amaz