bluuebunny/crossref_metadata_2025 huggingface dataset:
Consumo voluntário de forragem de três cultivares de Panicum maximum sob pastejo
Authors: Euclides Valéria Pacheco Batista , Thiago Luiz Roberto Lopes de S. , Macedo Manuel Claudio Motta , Oliveira Marcelo Paschoal de
Published: September 2011

Os objetivos deste trabalho foram estimar o consumo de matéria seca de animais pastejando três cultivares de Panicum maximum e relacioná-lo com ganho de peso, tempo de pastejo (TP) e algumas características químicas e estruturais do pasto. O delineamento experimental foi o de blocos casualizados com três tratamentos e três repetições. O consumo voluntário de matéria seca (CVMS) foi estimado em quatro ocasiões (maio, setembro, novembro e fevereiro). Para calcular a produção de fezes, foi usado o óxido crômico como marcador externo. Foram estimados a digestibilidade in situ da matéria seca e o tempo de pastejo, respectivamente, por intermédio de extrusas e tacógrafos. Foram estimadas as disponibilidades da forragem e dos componentes da planta. Apesar de os CVMS pelos animais terem sido semelhantes entre as cultivares, foram observadas maiores diferenças nos ganhos de peso, para os animais pastejando o capim Tanzânia, seguidos daqueles pastejando os capins Colonião e Tobiatã. Diferenças também foram observadas entre as cultivares para TP, que foi menor para os animais em pasto de Tobiatã, quando comparados aos que pastejaram as outras duas cultivares. O aumento no TP observado durante o período da seca não foi suficiente para impedir queda no consumo de forragem neste período. O CVMS foi correlacionado (r² = 0,77) com ganho diário de peso. As características estruturais das pastagens, disponibilidade de folhas e relação material verde:material morto, influenciaram mais o CVMS, ganho de peso diário e TP que os valores nutritivos das mesmas.
Sincronização da onda folicular com buserelina prévia à indução da luteólise com cloprostenol em bovinos
Authors: Costa Deiler Sampaio , Torres Ciro Alexandre Alves , Fernandes Carlos Antônio de Carvalho , Junqueira Luiz Arthur C. , Almeida Cláudia D'avila de , Alvim Sandro Campos
Published: September 2011

Este experimento foi realizado para verificar o efeito da aplicação de diferentes doses de um análogo de GnRH (buserelina) sobre a emergência de nova onda de crescimento folicular e o número de folículos recrutados dessa onda, a formação de corpo lúteo acessório, o diâmetro do folículo dominante e do corpo lúteo espontâneo no dia da aplicação do luteolítico e subseqüente taxa de sincronização e o intervalo da aplicação de PGF2α à manifestação do estro. Vinte fêmeas bovinas em diestro, mestiças Holandês x Zebu e Simental x Zebu foram, distribuídas em quatro tratamentos contendo cinco animais cada. No tratamento 1, os animais receberam 4 mg IM de buserelina no dia z 0 (dia em que se iniciou o tratamento) e 150 mg de D(+) cloprostenol no dia 6. Nos tratamentos 2, 3 e 4, receberam, respectivamente, 6, 8 e 10 mg de buserelina, pela mesma via de aplicação, e 150mg de D(+) cloprostenol no dia 6. A atividade ovariana foi monitorada diariamente, com auxílio do aparelho de ultra-sonografia, do dia 0 ao estro, ou até o dia 11 pós-tratamento, naqueles animais que não responderam à prostaglandina. A aplicação de 8 ou 10 mg de buserelina em fase indeterminada do diestro, nas fêmeas bovinas mestiças, promoveu emergência de nova onda de crescimento folicular mais rápida que aplicações de 4 ou 6 mg do mesmo hormônio; enquanto os outros parâmetros avaliados não diferiram entre os animais dos tratamentos.
Eficiência de utilização de nutrientes em novilhas das raças Canchim e Nelore e cruzadas Canchim-Nelore
Authors: Manzano Airton , Esteves Sérgio Novita , Freitas Alfredo Ribeiro de , Romano Marco Aurélio , Novaes Nelson José
Published: September 2011

O objetivo deste trabalho foi estudar a eficiência de utilização de nutrientes por novilhas em crescimento das raças Canchim (CA) e Nelore (NE) e 1/2 Canchim + 1/2 Nelore (CANE) em três dietas: mantença, relação volumoso:concentrado: (RVC) de 75:25 (Teste 1); dieta para ganhos de 700 g/animal/dia, RVC de 60:40 (Teste 2); e dieta para ganhos de 1200 g/animal/dia, RVC de 40:60 (Teste 3). Vinte e quatro novilhas foram usadas por teste, oito de cada grupo genético. Cada teste compreendeu três etapas: a) desempenho, de 90 dias, em que foram determinados o consumo de matéria seca e o ganho em peso diário dos animais; b) digestibilidade aparente das dietas e balanço de nitrogênio dos animais; e c) taxas de passagem da fase líquida da digesta. Os animais de CA, NE e CANE tiveram desempenho semelhante, dentro de cada dieta, para todas as variáveis analisadas.
Exigências de minerais para cabras SRD durante a gestação: cálcio e fósforo
Authors: Resende Kleber Tomás de , Costa Roberto Germano , Rodrigues Marcelo Teixeira , Espeschit Cláudio José Borela , Queiroz Augusto César de
Published: September 2011

Este trabalho foi realizado para estimar a retenção e a exigência líquida dos minerais Ca e P em 120 cabras sem raça definida (SRD), não-gestantes, com peso médio de 42 kg. A estimativa de retenção baseou-se na diferença entre o total de cada mineral depositado no feto, no útero, nas membranas, nos fluídos fetais e na glândula mamária dos animais nas diferentes etapas da gestação e o total de cada mineral armazenado nas cabras vazias. O modelo de predição usado foi lnY=A+BX+CX², em que X = tempo de gestação. Na comparação dos valores estimados com os valores reais obtidos, foi observado que o modelo proposto explicou com coerência e precisão o comportamento biológico da retenção dos minerais durante todas as fases da gestação. O conteúdo de Ca durante a gestação foi de 38,9 e 78,7 g nas gestações de um e dois fetos, resultando em exigência líquida diária de 1,17 e 3,72 g, respectivamente. O conteúdo de P foi de 17,8 e 29,1 g, resultando em exigência líquida diária de 0,48 e 0,71 g, respectivamente.
Influência da seleção sobre a qualidade da dieta ingerida por caprinos com feno oferecido em excesso
Authors: Silva José Humberto Vilar da , Rodrigues Marcelo Teixeira , Campos Joaquim
Published: September 2011

O objetivo deste trabalho foi avaliar o hábito alimentar, consumo de matéria seca e desempenho em cabras alimentadas com fenos de rami (Boehemeria nivea G.), soja (Neonotonia wightii (L.) M.) e capim-elefante napier (Pennisetum purpureum Sch.), oferecidos para permitir excesso de 30 ou 60%, acima do consumo medido do dia anterior. Trinta e seis cabras foram distribuídas em delineamento inteiramente ao acaso com seis tratamentos em arranjo fatorial de 3 x 2 (fenos e níveis de oferta). O tamanho médio de partícula dos fenos foi mantido constante em 0,4 cm. Os consumos de matéria seca e proteína bruta aumentaram quando o feno de rami foi oferecido com excesso de 60%, comparado a 30%. Houve redução no consumo de lignina quando o feno de soja foi oferecido no nível de 60%. Inversamente, decréscimo no consumo de proteína bruta e aumento no de fibra em detergente ácido e lignina foram observados, quando a oferta do feno de capim-elefante napier variou de 30 a 60%. Maior ganho em peso médio diário foi observado para os animais que consumiram o feno de rami. Estes resultados sugeriram que o feno de rami foi o mais indicado para uso em manejo de alimentação de cabras, com fenos oferecidos em excesso.
Efeito da inoculação de soluções nutritivas in ovo sobre a eclodibilidade e o desempenho de frangos de corte
Authors: Campos Anastácia Maria de Araújo , Rostagno Horacio Santiago , Gomes Paulo Cezar , Silva Eliane Aparecida da , Albino Luiz Fernando Teixeira , Nogueira Eduardo Terra
Published: September 2011

Objetivou-se avaliar a influência da inoculação de soluções nutritivas in ovo sobre a eclodibilidade e o desempenho de frangos de corte aos 21 dias de idade. Foram incubados 2.400 ovos, oriundos de matrizes Cobb com 40 semanas de idade, em 4 datas diferentes. Aos 17,5 dias de incubação, os ovos foram inoculados com 0,5 mL de uma das seguintes soluções nutritivas: solução salina 0,5%; solução de 2,0% de glicose + 2,0% de sacarose; solução de 2,5% de glicose + 3,0% de sacarose; solução de vitaminas ou solução de minerais quelatados. Todas as soluções foram avaliadas em comparação a um tratamento controle, constituído por ovos não inoculados. Para determinação da eclodibilidade, os pintos foram selecionados pelo sexo e distribuídos em delineamento de blocos ao acaso, em esquema fatorial 2 × 6 (dois sexos e seis soluções), com 8 repetições de 12 a 16 aves por unidade experimental. Aos 7 e 21 dias, foram determinados o ganho de peso, o consumo de ração e a conversão alimentar. Os rendimentos de peito, filé de peito e perna foram determinados no fim do experimento. A inoculação das soluções in ovo diminuiu a eclodibilidade, aumentando o número de ovos bicados e não-nascidos. O ganho de peso e a conversão alimentar das aves aos 7 dias de idade não foram afetados pela inoculação in ovo. Aos 21 dias, as soluções de 2,0% de glicose + 2,0% de sacarose, de vitaminas e de minerais não afetaram o desempenho, entretanto, a inoculação de 2,5% de glicose + 3,0% de sacarose proporcionou melhor conversão alimentar e aumento de 4,07% no ganho de peso, 5,07% no peso de peito com osso e 5,47% no peso de filé de peito. A inoculação de solução nutritiva contendo 2,5% de glicose + 3,0% de sacarose proporciona maior ganho de peso, melhor conversão alimentar, maior rendimento de peito com osso e rendimento de filé de peito das aves aos 21 dias de idade.
Zona de conforto térmico de ovinos da raça Santa Inês com base nas respostas fisiológicas
Authors: Eustáquio Filho Antônio , Teodoro Sônia Martins , Chaves Modesto Antônio , Santos Paulo Eduardo Ferreira dos , Silva Marcos Welber Ribeiro da , Murta Rogério Mendes , Carvalho Gleidson Giordano Pinto de , Souza Luiz Eduardo Barreto de
Published: September 2011

Objetivou-se estabelecer a zona de conforto térmico para ovinos da raça Santa Inês por meio da comparação das respostas fisiológicas em diferentes opções de temperatura em câmara bioclimática. O experimento teve duração de 71 dias e foi conduzido utilizando-se sete borregas da raça Santa Inês por tratamento. Os tratamentos foram as faixas de temperatura de 10, 15, 20, 25, 30, 35 e 40°C, com três repetições (dias de exposição) e cinco dias de intervalo. O delineamento experimental utilizado foi o inteiramente casualizado. Os dados meteorológicos coletados foram temperatura de bulbo seco, temperatura de bulbo úmido e temperatura de globo negro e os fisiológicos, frequência respiratória, frequência cardíaca, temperatura retal, temperatura timpânica, taxa de sudação e pressão arterial. Os mecanismos fisiológicos de dissipação de calor mostraram-se eficientes em manter a homeotermia dos animais em todas as temperaturas avaliadas. A temperatura de 25°C pode ser considerada a zona de conforto térmico para borregas da raça Santa Inês em ambiente com umidade relativa de 65%.
A reestruturação do sistema de pagamentos Brasileiro e seus impactos nas instituições financeiras
Authors: Brito Alan
Published: September 2011

Em 2002 devem ocorrer algumas mudanças significativas no Sistema de Pagamentos Brasileiro, em decorrência de decisões tomadas pelo Banco Central do Brasil, com o objetivo de aperfeiçoar os mecanismos de pagamentos na economia brasileira. Se estas modificações ocorrerem como o previsto, conduzirão a alterações no funcionamento do sistema financeiro. O objetivo deste presente documento é contribuir para o entendimento da natureza daquelas mudanças, sugerir seus prováveis impactos para o mercado financeiro e analisar as principais vantagens e desvantagens decorrentes da implementação do novo Sistema de Pagamentos Brasileiro.
A comparative study of the Bivalvia (Mollusca) from the continental shelves of Antarctica and Brazil
Authors: Passos Flávio Dias , Magalhães Frederico Thomaisino
Published: September 2011

During identification of bivalve molluscs collected in Antarctica, a rich taxonomic bibliography was gathered, stimulating comparisons with the Brazilian malacofauna. We listed a total of 68 and 368 known shallow-water species (less than 200 m depth) from Antarctica and Brazil, respectively, in order to find species, families and superfamilies in common, and to investigate how these malacofaunas differ in regard to these representative groups and their life habits. There are 23 superfamilies absent in Antarctica, but present in Brazil with at least one species; the reverse does not occur, as all superfamilies known from Antarctica are also recorded from Brazil. The number of Brazilian species is higher, being composed of a mixture of taxa from different biogeographical provinces, whereas in Antarctica there are only a few species adapted to its polar conditions, with minor components from elsewhere. Thus, many typical Caribbean species extend into Brazil, belonging to the diverse Arcoidea, Pectinoidea, Lucinoidea, Cardioidea, Veneroidea, and Tellinoidea. Cemented Ostreoidea, Plicatuloidea, Dimyoidea, Spondylidae (Pectinoidea), and Chamoidea are absent from Antarctica, as are wood (Teredinidae, Pholadoidea) and rock borers (Pholadidae, Pholadoidea; Gastrochaenoidea; and Lithophaginae, Mytiloidea). A large number of Brazilian species of infaunal (e.g., Tellinidae, Veneridae, Cardiidae, and Mactroidea) and epifaunal groups (Pectinidae, Mytilidae, and Arcidae) are absent from or poorly represented in Antarctica. Nuculanoidea, Limopsoidea, Lucinoidea, Galeommatoidea, Cyamioidea, and Cuspidarioidea are the richest groups in Antarctica; some of them are also represented by several species in Brazil, albeit in deeper waters. Three species are recorded as living in both places: Limatula pygmaea (Limidae), Lasaea adansoni (Lasaeidae), and Gaimardia trapesina (Gaimardiidae). Through the analysis of these groups from each fauna, it is possible to identify those that are taxonomically diverse in one place or another, and then emphasize them in ecological studies, eventually using them as model or monitoring organisms. The present paper can be a starting point for future discussion on the existing latitudinal gradients along the coast of eastern South America, stimulating studies on changes occurring in the composition of the faunas of bivalves from Brazil, Uruguay, Argentina, and Antarctica.
The distribution of the spectral bat, Vampyrum spectrum, reaches the Southern Pantanal
Authors: Silveira Maurício , Munin Roberto Lobo , Tomás Walfrido Moraes , Fischer Erich , Bordignon Marcelo Oscar , Silveira Guilli de Almeida
Published: September 2011

The largest New World bat, Vampyrum spectrum, is a locally rare top predator, which occurs from Mexico to South America. Here, we report for the first time its occurrence in the southern Pantanal floodplain, basing our records on specimens that are also the first to be reported for the State of Mato Grosso do Sul, Brazil. We conducted bat surveys in two sites 120 km apart, in the Aquidauana and Nhecolândia regions. Among 2,498 bat captures, two individuals of V. spectrum were mist-netted, one at each site. These records expand southward the distribution range of V. spectrum, and in addition to other records in the Northern Pantanal border and Bolivia support that V. spectrum is widely distributed in the upper Paraguay basin.
Are deep-sea cephalopods really common preys for oceanic seabirds?
Authors: Vaske Júnior Teodoro
Published: September 2011

An analysis of published data on oceanic seabirds diets, show the predominance of muscular cephalopods with superficial distribution in the oceanic layers, but also important are the gelatinous and ammoniacal species restrict to layers below 300 m from the surface. In principle, it could be not expected that deep-sea cephalopods are common prey for seabirds like several authors have been concluded. It is proposed in this study that an indirect source, important and easily attainable, have been appeared with the beginning of tuna longline operations. The habit to feed upon viscera of the fishes captured by tuna longliners, that discard the gut contents to the water, may explain the probable equivocal conclusions that deep dwelling cephalopods are natural prey of oceanic seabirds.
Redescription of Pseudopomyzella flava Hennig (Diptera: Cypselosomatidae) and the first record from Brazil
Authors: Carvalho-Filho Fernando da Silva , Esposito Maria Cristina
Published: September 2011

Cypselosomatidae is composed of Cypselosomatinae and Pseudopomyzinae, including 11 extant genera. Only the genus Rhinopomyzella Hennig (Pseudopomyzinae) has been previously recorded from Brazil, represented by two species from Santa Catarina. The genus Pseudopomyzella Hennig is comprised of a single species, Pseudopomyzella flava Hennig, previously found only in Peru and Ecuador. Here, we report P. flava for the first time from Brazil (Pará) and redescribe the species based on the specimens collected.
Variação temporal e espacial na composição de guildas alimentares da ictiofauna em lagoas marginais do Rio Cuiabá, Pantanal Norte
Authors: Ximenes Lidiani Queli Lubas , Mateus Lúcia Aparecida de Fatima , Penha Jerry Magno Ferreira
Published: September 2011

O presente trabalho teve como objetivo avaliar a variação espacial e temporal das guildas alimentares das comunidades de peixes em 10 lagoas marginais do Rio Cuiabá no Pantanal. As lagoas foram amostradas em três períodos do ciclo hidrológico (início e final da seca e início da enchente de 2005). As guildas alimentares foram determinadas através da análise do conteúdo estomacal das espécies mais abundantes da comunidade. Foram analisadas 37 espécies pertencentes a oito guildas alimentares (insetívora, herbívora, onívora, zooplanctívora, planctívora, detritívora, bentívora e iliófaga), as quais variaram espacial e temporalmente. Observamos uma mudança na composição das guildas tróficas entre os períodos e locais analisados, porém o número de guildas não variou espaço-temporalmente. Nossos resultados sugerem que as mudanças espaciais e temporais na composição das guildas podem estar relacionadas com diversos fatores, como as alterações na composição da comunidade onde novas espécies podem compor as diferentes guildas; a exploração de recursos mais abundantes em determinadas épocas do ano favorecendo a presença de algumas guildas somente em alguns períodos.
Vertebrados da Estação Ecológica Serra Geral do Tocantins: faunística, biodiversidade e conservação no Cerrado brasileiro
Authors: Nogueira Cristiano de Campos , Ferreira Mariana Napolitano e , Recoder Renato Sousa , Carmignotto Ana Paula , Valdujo Paula Hanna , Lima Flávio César Thadeo de , Gregorin Renato , Silveira Luís Fábio , Rodrigues Miguel Trefaut
Published: September 2011

Inventários e estudos faunísticos detalhados sobre vertebrados são uma das fontes mais relevantes de dados para interpretações de padrões detalhados de diversidade biológica. Dados básicos e de boa qualidade sobre faunística são ainda mais urgentes em regiões pouco estudadas e sob intensa ameaça antrópica, tais como a região do Cerrado, um dos 34 hotspots globais para a conservação da biodiversidade. Apresentamos aqui uma síntese dos resultados dos inventários de vertebrados na Estação Ecológica Serra Geral do Tocantins (~716.000 ha), a segunda maior unidade de conservação em todo o Cerrado. Foram registradas 450 espécies de vertebrados na EESGT e entorno imediato, incluindo 17 espécies ameaçadas, 50 espécies endêmicas do Cerrado e 11 espécies com distribuição potencialmente restrita. Do total de espécies amostradas, 180 são novos registros para a região do Jalapão. Ao menos 12 espécies amostradas foram consideradas potenciais espécies novas, das quais quatro foram descritas recentemente, a partir do material obtido no inventário. Os resultados evidenciam que a EESGT é uma das mais importantes áreas protegidas no Brasil central, contribuindo para a persistência de espécies ameaçadas, dependentes dos últimos grandes blocos contínuos de vegetação nativa de Cerrado. Nossos resultados indicam ainda que a conservação da EESGT e suas principais subunidades é crucial para a representatividade do sistema de áreas protegidas do Cerrado, protegendo potenciais endemismos restritos que aliam alta vulnerabilidade intrínseca e valor como indicadores de padrões e processos biogeográficos formadores da rica e cada vez mais ameaçada fauna Neotropical.
Borboletas frugívoras (Lepidoptera: Nymphalidae) ocorrentes em um fragmento de Floresta Ombrófila Mista no Rio Grande do Sul, Brasil
Authors: Pedrotti Vanessa Schaeffer , Barros Marcelo Pereira de , Romanowski Helena Piccoli , Iserhard Cristiano Agra
Published: September 2011

O presente estudo tem como objetivo contribuir para o conhecimento das borboletas frugívoras em diferentes ambientes de um fragmento de Floresta Ombrófila Mista no município de São Francisco de Paula, região Nordeste do Rio Grande do Sul. As amostragens foram realizadas mensalmente entre março de 2008 e fevereiro de 2009 em duas transecções. Em cada transecção foram colocadas oito armadilhas atrativas fermentadas com banana e caldo de cana ao longo de três dias por ocasião amostral. Após um total de 5760 horas de amostragem foram registradas 30 espécies pertencentes a três subfamílias e seis tribos de borboletas frugívoras. Três espécies são novos registros para a Floresta Ombrófila Mista do Rio Grande do Sul: Prepona pylene pylene, Narope cyllastros e Opoptera sulcius, tendo esta última registro publicado para a região sudeste do estado.
Composição taxonômica da assembleia de larvas de peixes no reservatório de Rosana, Rio Paranapanema, Brasil
Authors: Kipper Darlon , Bialetzki Andréa , Santin Miriam
Published: September 2011

Em reservatórios, são escassos os estudos que consideram as fases iniciais do ciclo de vida de peixes, sendo que informações sobre a ecologia de larvas de peixes são úteis para o entendimento da biologia das espécies, visto que os estágios iniciais representam um período crítico no ciclo de vida dos peixes. Neste contexto, o conhecimento a respeito das assembleias de larvas pode ser valioso para a predição e o entendimento do recrutamento, auxiliando desta maneira, no manejo do ambiente. Desta forma, o presente trabalho pretende verificar a composição da assembleia de larvas de peixes em diferentes regiões do reservatório. As coletas foram realizadas trimestralmente (março, junho, setembro e dezembro) no ano de 2002, nas regiões limnética e litorânea das zonas fluvial, transição e lacustre do reservatório de Rosana. No laboratório, o material foi triado e as larvas foram separadas e identificadas ao menor nível taxonômico possível. Os táxons que tiveram maior contribuição na região limnética foram Plagioscion squamosissimus (Perciformes), Hypophthalmus edentatus, Pimelodus maculatus (Siluriformes), Astyanax spp. e Roeboides descalvadensis (Characiformes), enquanto na região litorânea Bryconamericus stramineus e Apareiodon affinis (Characiformes). As regiões limnética e litorânea do reservatório, assim como suas respectivas zonas apresentaram diferenças na composição de espécies de larvas e a segregação das assembleias pode estar sendo influenciada pela preferência por habitats ou por questões evolutivas que envolvem as estratégias reprodutivas das espécies.
Látex de amapá (Parahancornia fasciculata (Poir) Benoist, Apocynaceae): remédio e renda na floresta e na cidade
Authors: Silva Murilo da Serra , Fantini Alfredo Celso , Shanley Patricia
Published: September 2011

O estudo abordou a cadeia de produção e de comercialização e os aspectos do consumo do látex medicinal de amapá amargoso (Parahancornia fasciculata) em Belém e Ponta de Pedras, no Pará. Nosso objetivo foi investigar diversos aspectos do manejo e uso desse produto, revelando a sua importância na vida de seus produtores e consumidores. Foram utilizados a abordagem da 'cadeia de produção ao consumo' e métodos qualitativos e quantitativos de pesquisa, incluindo pesquisa de mercado, entrevistas com extrativistas, comerciantes e consumidores, oficinas, turnês guiadas e inventário florestal. Os oito mil litros de látex de amapá comercializados anualmente na região de Belém beneficiam, principalmente, consumidores de baixa renda, que têm tradição secular do uso desse látex. A renda obtida com esse produto representa 42% da renda total dos extrativistas com produtos florestais não madeireiros. A grande abundância da espécie e a distribuição diamétrica das árvores indicam possibilidade de regeneração natural. A melhoria na técnica de extração do látex realizada por alguns extrativistas revela que eles têm conhecimento da anatomia da árvore. A tradição de uso e manejo do látex e as características ecológicas da espécie sugerem grande potencial para programas de produção sustentável.
Seasonal and genetic influences on sex expression in a backcrossed segregating papaya population
Authors: Ramos Helaine Christine Cancela , Pereira Messias Gonzaga , Silva Francisco Filho da , Viana Alexandre Pio , Ferreguetti Geraldo Antônio
Published: September 2011

This study aimed to evaluate the genetic and seasonal influence on sex expression in segregating generations of papaya elite and backcrossed genotypes. In the four seasons of the 2005/2006 growing season, 200 hermaphrodite plants were evaluated. Of the eight studied traits, four were related to flowering and four to fruiting, i.e., to the percentage of normal, deformed, sterile, and total number of flowers, as well as the percentage of total, carpelloid, pentandric, and marketable fruits. Significant differences due to the genotype x season interaction were verified. Based on the genotypic determination coefficient and the variation index it was concluded that winter and spring are most appropriate for the selection of superior genotypes. Thus, selection in early stages of plant development is more successful, indicating that the physiological age may also be a factor involved in the expression of the above traits.
Prediction of genetic gains from selection in Arabica coffee progenies
Authors: Oliveira Antonio Carlos Baião de , Pereira Antonio Alves , Silva Felipe Lopes da , Rezende Juliana Costa de , Botelho César Elias , Carvalho Gladyston Rodrigues
Published: September 2011

Gains from selection for yield were estimated in Arabica coffee progenies carrying rust-resistance genes. The experiment in augmented block design was installed in Três Pontas, state of Minas Gerais. Three blocks were established with six plants per plot, spaced 3.50 x 0.90 m, in 96 regular (F2 progenies) and two control treatments. The plant response to rust was evaluated on a grade scale in 2008. Yield (bags per hectare) was estimated in the growing seasons 2005 to 2008. Significant differences between treatments for yield were observed in all harvests, except 2005. The presence of genetic variability among progenies allowed significant gain from selection for yield. Under the experimental conditions of this study, selection for yield can be performed in the first high-yield year, without major losses compared to genetic gain from selection for yield when based on the mean of four harvests.
Benthic–planktonic coupling, regime shifts, and whole‐lake primary production in shallow lakes
Authors: Genkai-Kato Motomi , Vadeboncoeur Yvonne , Liboriussen Lone , Jeppesen Erik
Published: September 2011

Alternative stable states in shallow lakes are typically characterized by submerged macrophyte (clear‐water state) or phytoplankton (turbid state) dominance. However, a clear‐water state may occur in eutrophic lakes even when macrophytes are absent. To test whether sediment algae could cause a regime shift in the absence of macrophytes, we developed a model of benthic (periphyton) and planktonic (phytoplankton) primary production using parameters derived from a shallow macrophyte‐free lake that shifted from a turbid to a clear‐water state following fish removal (biomanipulation). The model includes a negative feedback effect of periphyton on phosphorus (P) release from sediments. This in turn induces a positive feedback between phytoplankton production and P release. Scenarios incorporating a gradient of external P loading rates revealed that (1) periphyton and phytoplankton both contributed substantially to whole‐lake production over a broad range of external P loading in a clear‐water state; (2) during the clear‐water state, the loss of benthic production was gradually replaced by phytoplankton production, leaving whole‐lake production largely unchanged; (3) the responses of lakes to biomanipulation and increased external P loading were both dependent on lake morphometry; and (4) the capacity of periphyton to buffer the effects of increased external P loading and maintain a clear‐water state was highly sensitive to relationships between light availability at the sediment surface and the of P release. Our model suggests a mechanism for the persistence of alternative states in shallow macrophyte‐free lakes and demonstrates that regime shifts may trigger profound changes in ecosystem structure and function.
An Active Method for Characterization of Flow Units Between Injection/Production Wells by Injection-Rate Design
Authors: Lee Kun-Han , Ortega Antonio , Nejad Amir Mohammad , Ershaghi Iraj
Published: September 2011

This paper presents a novel data-mining method to characterize the flow units between injection and production wells in a waterflood, using carefully implemented variations in injection rates. The method allows the computation of weight factors representing the influence of any of the injectors surrounding a given producer. The weight factors are used to characterize the effective contribution of injection wells to the total gross production in surrounding production wells. A wavelet approach is used to design the perturbation in the injection rates and to analyze the observed variations in the gross production rates.

Tracking the contribution of injectors to various producers can help in balancing voidage replacement in waterflood optimization. A second application is reservoir characterization, in which information provided by the proposed procedure can help in mapping high-permeability flow units such as channels and fractures as well as flow barriers between wells. The method was calibrated and tested successfully for simulated line-drive and five-spot patterns with various assumed flow units and flow-heterogeneity conditions. The paper also includes a case study for a tight-formation waterflood in which the weight factors are intended to delineate the pattern of natural high-permeability channels causing preferential flows.
Multiscale Mimetic Solvers for Efficient Streamline Simulation of Fractured Reservoirs
Authors: Natvig J.R.. R. , Skaflestad B.. , Bratvedt F.. , Bratvedt K.. , Lie K.-A.. -A. , Laptev V.. , Khataniar S.K.. K.
Published: September 2011

Advances in reservoir characterization and modeling have given the industry improved ability to build detailed geological models of petroleum reservoirs. These models are characterized by complex shapes and structures with discontinuous material properties that span many orders of magnitude. Models that represent fractures explicitly as volumetric objects pose a particular challenge to standard simulation technology with regard to accuracy and computational efficiency.

We present a new simulation approach based on streamlines in combination with a new multiscale mimetic pressure solver with improved capabilities for complex fractured reservoirs. The multiscale solver approximates the flux as a linear combination of numerically computed basis functions defined over a coarsened simulation grid consisting of collections of cells from the geological model. Here, we use a mimetic multipoint-flux approximation to compute the multiscale-basis functions. This method has limited sensitivity to grid distortions. The multiscale technology is very robust with respect to fine-scale models containing geological objects such as fractures and fracture corridors. The methodology is very flexible in the choice of the coarse grids introduced to reduce the computational cost of each pressure solve. This can have a large impact on iterative modeling workflows.
Planning and Execution of Highly Overbalanced Completions From a Floating Rig: The Ursa-Princess Waterflood Project
Authors: Stair Craig D. , Hinnant Chuck H. , Hines Natalya O. , Schober Jamie M. , Davis Chris L. , Lizak Ken F. , Pugh Brian A.
Published: September 2011

The Ursa-Princess Waterflood (UPWF) targets the Lower Yellow sand, the main reservoir in the Mars-Ursa basin in Mississippi Canyon, approximately 60 miles south of the mouth of the Mississippi River in the Gulf of Mexico (GOM). The Lower Yellow sand, a world-class Upper Miocene turbidite reservoir, has been on production in the Ursa and Princess fields since 1999, and has been drawn down nearly to the bubblepoint. The waterflood is intended to increase and stabilize reservoir pressure, and to improve sweep efficiency. To accomplish this, four subsea injectors were designed and constructed to inject treated seawater at 40,000 B/D each for a target life of 30 years.

Because the Lower Yellow reservoir was already highly depleted, unique risks were identified in the planned subsea completion operations, to be conducted from a mobile offshore drilling unit (MODU). Seawater, used as a completion fluid, was expected to be up to 4,000 psi overbalanced to the reservoir, depending on the well location. This created the risk of either an uncontrollable fluid-level drop in the marine riser or an extreme impairment to the sandface completion. In order to maintain well control with a fluid level at the surface and still deliver low-skin completions, multiple design and procedural issues needed to be addressed, including the following:

Control systems on the rig and riser system to prevent uncontrollable fluid-level drop. Perforating systems to minimize impairment in a highly overbalanced environment without adding undue risk to well control. Pill designs that could both control fluid loss at the sandface and clean up effectively. Downhole completion systems capable of functioning either under very high pressure differentials or against very high loss rates. Development of high-burst screens suited to the use of fluid-loss-control pills as a contingency provision in the event that mechanical fluid-loss devices failed.

As more deepwater reservoirs approach depletion, specialized tools and procedures will be required to continue to deliver safe and effective sandface completions from floating rigs. This paper details many of these considerations and summarizes the execution experience and results for one such reservoir.
A Major Advancement in Expandable Connection Performance, Enabling Reliable Gastight Expandable Connections
Authors: DeLange Richard , Gandikota Raju , Osburn Scott
Published: September 2011

Since the introduction almost 15 years ago of today's solid-expandable-liner systems, threaded-connection technologies have advanced very little compared with the development of sophisticated, state-of-the-art expansion tools and systems. The severity of damage caused to threaded connections during the downhole expansion process leaves some threads unengaged and badly deformed, reducing the connections’ mechanical dependability. Even worse, traditional metal seals incorporated into most proprietary premium connections are destroyed during the expansion process or damaged to the point of being undependable.

Even though solid-expandable-liner systems offer a large number of important and valuable solutions, connection performance is obviously a problem. For more than a decade, engineers have worked on the development of connection features that are more resistant to damage caused during expansion. Although there has been some advancement, today most or all expanded connections share little resemblance to unexpanded connections when subjected to ISO 13679 (2002) qualification tests with gas.

This paper details new expansion-cone technology that eliminates the majority of damage caused to connections when expanded with traditional cones. This paper will provide finite-element analyses and physical-testing verification to show how this new technology leaves connections with minimal visible damage to the threads and metal seals after expansion.
The Effect of CO2-Saturated Brine on the Conductivity of Wellbore-Cement Fractures
Authors: Yalcinkaya Tevfik , Radonjic Mileva , Hughes Richard G. , Willson Clinton S. , Ham Kyungmin
Published: September 2011

The efficiency of carbon-capture and -storage (CCS) projects is directly related to the long-term sealing ability of cemented sections in wellbores penetrating CO2-storage reservoirs. The microfractures inside the wellbore cement and/or microannuli are possible pathways for CO2 leakage to the surface and/or freshwater-aquifer leakage and could jeopardize safe and long-term containment of CO2 in the subsurface. This paper presents an experimental study that investigates the changes inside the cement internal structure when exposed to acidic brine through an artificial fracture. A 30-day-long flow-through experiment was conducted using a 1 × 12-in. cement core and CO2-saturated brine as a permeant at a flow rate of 2 mL/min in a coreflooding apparatus with 10 and 600 psi of injection and net overburden pressure, respectively [low-pressure (LP) experiment]. The same experiment was repeated with the same flow rate but with 1,800 and 600 psi of injection and net overburden pressures, respectively, for 10 days in order to account for the effects of pressure on the degradation process of cement [high-pressure (HP) experiment]. High-resolution X-ray computed tomography (CT) was used to image several subvolumes extracted from the flow-through cores. The images were processed and thresholded, followed by calculation of porosity. Total porosity was observed to decrease from 26 to 22% after 30 days of exposure in the LP experiment. The HP experiment did not cause any significant change in total porosity, possibly because of the short duration of the experiment.
Effects of Injected-Water Salinity on Waterflood Sweep Efficiency Through Induced Fines Migration
Authors: Lemon Phillip , Zeinijahromi Abbas , Bedrikovetsky Pavel , Shahin Ibrahim
Published: September 2011

Permeability decline during corefloods with varying water composition, especially with low-salinity water, has been observed in numerous laboratory studies. It has often been explained by the lifting, migration, and subsequent plugging of pores by fine particles, which have been observed in numerous coreflood tests with altered water composition. In this paper, we investigated the concept that this permeability decline may be used for mobility control during waterflooding. The Dietz model for waterflooding in a layer-cake reservoir with a given injection and production rate was combined with a particle-detachment model to provide a simple analytical model for the process. The application of the model to an example data set showed that the induced fines migration may improve sweep efficiency.
Transient Nonisothermal Fully Coupled Wellbore/Reservoir Model for Gas-Well Testing, Part 1: Modelling
Authors: Bahonar Mehdi , Azaiez Jalel , Chen Zhangxing John
Published: September 2011

A numerical fully implicit nonisothermal wellbore/reservoir simulator is developed. The model entails simultaneous solution of transient coupled mass-, momentum-, and energy-balance equations within the wellbore; energy-balance equations for the tubular and cement materials and the formation surrounding the wellbore; and mass-balance and flow-rate/pressure equations for the reservoir formation. A wellbore heat-loss model that is a strong feature of this study is developed and employed in the model to improve the accuracy of the simulator and to be able to estimate the casing temperature and formation-temperature distribution. The model formulation is completed with an equation of state (EOS) to estimate fluid properties and appropriate friction-factor correlations in the wellbore tubing to compute the frictional pressure drop for different flow regimes.

The developed model has several applications in the petroleum industry, particularly in the gas-well testing design and interpretation of both isothermal and nonisothermal gas reservoirs.

This nonisothermal simulator is validated through comparisons to both analytical models and an equivalent numerical isothermal coupled wellbore/reservoir simulator that is also developed in this paper. Applications of this simulator to analyzing gas-well testing problems, in addition to several important observations, are extensively studied in Part 2 of this research work (Bahonar et al. 2010).

Currently, it has been well accepted that the applicability and significance of a reservoir simulator depend on the behaviour of the wellbore and interaction between the wellbore and reservoir. A robust, accurate coupled wellbore and reservoir simulator is an invaluable tool for the petroleum engineer to help the petroleum industry understand production behaviour, make a meaningful prediction, and make correct decisions in all field-development and production stages.
Transient Nonisothermal Fully Coupled Wellbore/Reservoir Model for Gas-Well Testing, Part 2: Applications
Authors: Bahonar Mehdi , Azaiez Jalel , Chen Zhangxing John
Published: September 2011

After the development of a numerical fully implicit nonisothermal wellbore/reservoir simulator in Part 1 of this study (Bahonar et al. 2010), this simulator is implemented for a close and detailed study of gas-well pressure-drawdown (DD) and -buildup (BU) tests. Overall, the developed simulator is an accurate and strong tool for design and analysis of transient gas-well testing, particularly for high- pressure/high-temperature (HP/HT) gas reservoirs.

Several numerical results will be presented. This includes demonstration of the behaviour of the wellbore-fluid pressure, temperature, density, and velocity and an overall heat-transfer coefficient during DD or shut-in tests for nonisothermal reservoirs and conceptual comparisons with the isothermal counterparts. Thermal effects on the behaviour of derivative plots and the sandface-flow rate of deep nonisothermal gas reservoirs will be studied. A significant effect of neglecting the heat capacity of tubular and cement materials on the wellhead-temperature simulation, and thus transient well tests, will be demonstrated. A sample case to show that neglecting the thermal effects in the gas-well tests of composite reservoirs leads to unreliable results in well-testing analysis will be presented. Several other numerical experiments, including the presence of a variable wellbore-storage coefficient, gas backflow from the wellbore to the reservoir, and other thermal effects during the gas-well tests, are also presented.

Hundreds of millions of dollars are spent every year on well testing around the world (Hawkes et al. 2001). A proper design and truthful interpretation of these tests can be achieved by a reliable coupled wellbore/reservoir simulator, which in turn can save a large portion of the required costs.
Controllability of Distillation Sequences for the Separation of Ternary Mixture
Authors: Nadendla Rajasekhar , Venu Vinod A.
Published: September 2011

The present work aims at finding the best distillation sequence in terms of control properties for the separation of a ternary mixture of n-pentane, n-hexane and n-heptane. The study has been carried out using ASPEN PLUS. The different sequences have been compared for regulatory problem (step change in feed concentration and feed flow rate) and servo problem (step change in product composition). PI controller has been used to control level and composition in the various configurations studied. Auto tuning of the controller has been carried out using relay feedback test. Ziegler–Nichols method was used to calculate controller gain (KI) and integral time (τI) of PI controller. Controller parameters have been fine tuned using these tuning maps.
Management of used tires, accomplishments in the world, and situation in Serbia
Authors: Stanojevic Dusan , Rajkovic Milos , Toskovic Dragan
Published: September 2011

It is estimated that all over the world there are more than 550 million road
vehicles in everyday use. Annually, 1.3 billion used tyres are dismantled
from these vehicles due to safety reasons. A small number of these tyres end
up reused as second-hand tyres or, after being retreated, as new ones. The
rest are end of life tyres which are recycled or used as tire derived fuels
under controlled combustion conditions. Modern vehicle tyres are a
high-technological product containing, on the average, 85% hydrocarbon,
10-15% steel, as well as some other chemical materials. Tyres belong to high
caloric materials, with calorific value of a passenger car tyre of approx.
30.2 MJ/kg being more than of hard coal and comparable to calorific value of
petrol-coke. Having this in mind many countries use end of life tyres as safe
alternative fuel in cement works or power plants. Undeveloped countries dump
end of life tyres on legal and illegal scrap stockpiles. End of life tyres,
if deposed correctly, don?t endanger the environment because they are
chemically inert. However, since they can easily be burnt there is a real
possibility of tyre dump fires, which in effect can lead to harmful products
emission that extremely pollute the environment. End of life tyres represent
a very important secondary material, which when recycled is transformed into
a number of raw materials used in rubber industry, for road construction,
sports facilities, residential and business buildings, artificial fish
habitats in shallow seas, sea walls, steel production, etc. By the industrial
procedures of controlled degradation, which have been uneconomical up till
now, gaseous and liquid fuel can be obtained by natural rubber, steel and
soot recycling. The countries of the EU, together with Norway and
Switzerland, were the world leaders in the field of effective end of life
tyre management in the year 2009. Out of 2.62 million tonnes of end of life
tyres, 95% were restored or used as energents, and 5% settled on dumps. About
26.000 t of used tyres are collected in Serbia each year. In accordance with
adopted legal legislations, up to 30% can be used as tire derived fuels while
70% are being recycled. Serbia belongs to the group of countries which have
solved the problem of used tyres in a modern way, and in accordance with EU
Legislation practice.
Changes in teaching of nontechnical skills, knowledge, aptitudes, and attitudes at US colleges and schools of veterinary medicine between 1999 and 2009
Authors: Harris Donna L. , Lloyd James W.
Published: September 2011

Objective—To identify changes in the teaching of nontechnical skills, knowledge, aptitudes, and attitudes (SKAs) at US colleges and schools of veterinary medicine between 1999 and 2009.

Design—Cross-sectional survey.

Sample—All 28 US colleges and schools of veterinary medicine.

Procedures—An electronic questionnaire was sent to the entire study population. Results were compared with published results of a similar survey performed in 1999 of colleges and schools of veterinary medicine in the United States and Canada.

Results—A 100% response rate was achieved. All respondents were found to offer at least 1 course related to SKAs in 2009, compared with 94% (29/31) of respondents in 1999. A total of 110 such courses were documented, compared with 47 in 1999. In 2009, 26 of the 28 (93%) colleges and schools had at least 1 course related to SKAs that was required, compared with 17 of the 31 (55%) respondents to the 1999 survey. Courses were most commonly incorporated in years 1 and 3 of the curriculum and were most often valued at 1 or 2 credit hours. Forty-one of 67 (61%) courses had been developed since 1999. The most common topics were communication and financial management.

Conclusions and Clinical Relevance—Results demonstrated an increased commitment to teaching the SKAs on the part of the US colleges and schools of veterinary medicine. However, the question remains as to how effective these initiatives will be in enhancing the economic success of graduates and the veterinary medical profession in general.