bluuebunny/crossref_metadata_2025 huggingface dataset:
Susceptibilities to carbapenems and presence of cphA gene on food-borne Aeromonas
Authors: Martín Talavera Bibiana María , Benassi Fernando Olivio , von Specht Martha Helena , Quiroga Marina Inés , García Myriam Alicia , Pucciarelli Amanda Beatríz , Zubreski Emilce , Laczeski Margarita Esther , Gutkind Gabriel
Published: September 2006

The purpose of this study was to determine the susceptibilities of food-borne Aeromonas to carbapenems, as well as to investigate the presence of a metallo carbapenemase-encoding gene, named cphA. Minimum Inhibitory Concentration (MIC) was determined following NCCLS standards. All the tested microorganisms were susceptible to imipenem, meropenem and biapenem. However, a strong inoculum size effect on carbapenem MICs was observed for most of the strains. Six strains, out of seven, showed the presence of metallo--beta-lactamases but cphA gene was detected in only two strains of A. veronii bv. sobria.
Aporias políticas e psicológicas dos estudos literários latino-americanos: para uma leitura do livro Literatura comparada na América Latina, de Eduardo Coutinho
Authors: Losso Eduardo Guerreiro Brito
Published: September 2006

O artigo discute questões importantes para a crítica e para a teoria da literatura, levantadas por Eduardo Coutinho em livro recente, entre as quais a "maioridade" da teoria na América Latina, a inalterável necessidade do valor estético na discussão acerca dos estudos culturais, a abordagem da "pobre elite literária" e a relação entre o marxismo (Adorno) e os estudos pós-coloniais.
O impacto epistemológico das investigações sobre "complexidade"
Authors: Jorge Maria Manuel Araújo
Published: September 2006

A complexidade proposta coma idéia filosófica (embora a partir das ciências que a abordam) foi tida, por alguns, como a expressão de um novo "espírito epistemológico" que estaria a mudar não só a nossa imagem mecanicista da natureza mas, também, a nossa relação com ela e o modo de fazer ciência, numa aproximação mais qualitativa, menos agressiva e mais humana. Superando o reducionismo tradicional, reconhecendo a autonomia e as inter-relações entre os diferentes níveis da realidade, a simbiose entre a ordem e a desordem, as regularidades e o aleatório, as ciências assimilando o espírito da complexidade, estariam abertas a uma consciência dos seus limites fundamentais. Pela consideração da abordagem de "sistemas complexos" em algumas disciplinas, defendo que, por exigências de eficácia e objectividade, a busca de simplificação, compressão, e o esforço do "cálculo" de todos os seus objectos, permanece, ainda, a face típica das ciências, mesmo as da "complexidade".
La complejidad en la totalidad dialéctica
Authors: Massé Narváez Carlos
Published: September 2006

El trabajo parte de mostrar las limitaciones de los discursos sustantivos disciplinarios. Enseguida se expone la complejidad los conceptos de realidad, presente y utopía, para con ello, discutir cómo ocurre la producción de conocimiento científico, pero alertando al lector, sobre sus límites frente a la contradictoriedad de lo real. Frente a las contingencias imprevistas que siempre se presentan en dicho proceso, se exponen las categorías de Esperanza y Utopía, para finalmente proponer una apropiación del conocimiento, como conocimiento científico a través de una articulación transdisciplinaria, que garantice la apropiación de la complejidad de lo real, como totalidad.
Sociologia na complexidade
Authors: Lima Gilson
Published: September 2006

O artigo se propõe a fazer uma introdução didática e informativa e, ao mesmo tempo, aprofundada sobre as conseqüências da emergência do paradigma da complexidade para a Sociologia. No desenrolar da narrativa, faz comparações, o que permite ao leitor não familiarizado com a temática da ciência identificar as diferenças macroparadigmáticas pré-modernas, da modernidade simples e da emergência do paradigma da complexidade. Define e exemplifica, sempre que possível, os termos, afirmações e princípios significativos para uma melhor compreensão do tema. Faz, também, inúmeras indicações, no interior da narrativa, de autores e obras, para que aqueles que desejarem continuar, possam mergulhar mais intensamente nos caminhos da sociologia da complexidade. O artigo inicia com uma introdução que define, a partir de Thomas Kuhn, o conceito de paradigma. A seguir, desenvolve de modo comparado, os princípios mais importantes do paradigma da complexidade. E, por fim, chama a atenção para alguns desafios da Sociologia na complexidade, alertando para os riscos da paralisação da complexidade na difícil tarefa de religarmos os saberes diante da hiperespecialização presente na crise do paradigma da modernidade simples.
A reinvenção dos corpos: por uma pedagogia da complexidade
Authors: Gaya Adroaldo
Published: September 2006

O objetivo deste ensaio é o de reivindicar a presença do corpo humano nas reflexões epistemológicas e pedagógicas. Parte-se da seguinte hipótese: Em tempos pós-modernos, os discursos filosófico e sociológico apontam para a superação da racionalidade iluminista. As propostas pedagógicas procuram perspectivas interdisciplinares, novas formas de configuração curricular e de organização do espaço escolar. Muito seguidamente ouvem-se referências a uma pedagogia da complexidade. Todavia, paradoxalmente, é nesta mesma escola e no âmbito dessa mesma pedagogia que o paradigma do racionalismo iluminista inspirador de uma educação intelectualista permanece, assumindo a herança cartesiana que concebe o corpo como simples extensão da mente. Três temas compõem os argumentos em defesa da hipótese orientadora: (1) Nas escolas de nosso tempo o corpo considerado como res extensa permanece passivo. Enfim, o corpo não vai à escola. (2) As principais correntes epistemológicas sobre a origem do conhecimento, da mesma forma, limitam-se a expressões de um conhecimento predominantemente racional. O corpo permanece ausente de interesse epistemológico. (3) Uma pedagogia que se limita ao exclusivamente racional é míope e, por conseqüência, não pode exigir configurar-se numa pedagogia da complexidade. É necessário recolocar os corpos na epistemologia, na pedagogia e nas escolas. É a reinvenção dos corpos.
Sistemas de informação em saúde e monitoramento de morbidade materna grave e mortalidade materna
Authors: Sousa Maria Helena de , Cecatti José Guilherme , Hardy Ellen Elizabeth , Amaral Eliana , Souza João Paulo Dias de , Serruya Suzanne
Published: September 2006

Nas últimas décadas, nos países desenvolvidos houve queda acentuada da mortalidade materna, enquanto nos países em desenvolvimento a queda foi pequena ou não ocorreu. De qualquer forma, como o óbito materno, em termos absolutos, é pouco freqüente, os eventos mórbidos maternos graves tornaram-se o foco das atenções, por representarem "eventos sentinela" ao óbito. No Brasil a principal fonte de informações em saúde é o Ministério da Saúde, através de seu sistema chamado DATASUS. A utilização dessas informações rotineiras, disponíveis nos diversos sistemas de informação públicos de saúde pode ser útil não apenas para o mapeamento diagnóstico de morbidade grave e mortalidade materna, mas também para seu monitoramento contínuo e prospectivo, criando um sistema de alerta ou de vigilância que permita, quando ativado, desencadear intervenções terapêuticas ou preventivas para evitar a ocorrência do óbito materno, constituindo uma inovação e um desafio a ser testado em futuro próximo.
Avaliação antropométrica de pré-escolares do município de Mogi-Guaçú, São Paulo: subsídio para políticas públicas de saúde
Authors: Fernandes Isidoro Tadeu , Gallo Paulo Rogério , Advíncula Alberto Olavo
Published: September 2006

OBJETIVOS: analisar o estado nutricional, através de avaliação antropométrica, dos pré-escolares que freqüentam Escolas Municipais de Educação Infantil (EMEIs) de Mogi-Guaçú, São Paulo, Brasil. MÉTODOS: a partir de uma amostra por conglomerado, estimada pela equiprobabilidade, com participação de 347 crianças de três a sete anos de idade, matriculadas em nove EMEIs, das 38 existentes na pesquisa, foram tomadas medidas individuais de peso e estatura, complementadas por questionário com informações socioeconômicas familiares. As medidas foram controladas com o uso de escores z e comparadas com o referencial do Centro Nacional de Estatísticas da Saúde dos Estados Unidos da América, e o índice de massa corporal. RESULTADOS: verificou-se um provável deslocamento da média dos índices antropométricos para a direita da curva normal no tocante ao escore z dos indicadores peso/idade (+0,54; dp 1,48), altura/idade (+0,20; dp 1,02), IMC (+0,30; dp 1,13). CONCLUSÕES: a caracterização da situação nutricional das crianças matriculadas nas EMEIs não aponta para risco de desnutrição protéico-energética (DPE). Em contrapartida, observou-se, como problema, a presença de sobrepeso e obesidade.
Brain white matter lesions correlated to newborns death and lethality
Authors: Argollo Nayara , Lessa Ines , Ribeiro Suely , Abreu Katiusha C. , Pinto Juliana M.S. , Faria Raquel P. , Telles Tatiana G. , Santos Gabriel
Published: September 2006

OBJECTIVES: to describe hospital lethality rates and factors correlated to death in neonates with brain white matter lesions. METHODS: a retrospective study was performed from January 1994 to December 2001. Neonates with white brain matter lesions were divided into survival and death groups and their medical files reviewed through the single blind method to determine evolution. Death certificates provided the cause of death. The groups were compared through correlation coefficients. Hospital lethality rate was calculated. RESULTS: ninety three cases of white brain matter lesions and seven deaths were determined. Hospital lethality rate was of 8.2.% (95%CI: 2.4-14.0) independently from lesion occurrence time, and of 10.3% (95%CI: 3.3-17.3) for deaths occurred during prenatal and perinatal periods. Death was correlated to: Apgar score, non-cephalic presentation, gestational age, hyperglicemia, hypercalcemia, convulsion, respiratory insufficiency and atelectasy. CONCLUSIONS: hospital lethality was of 10.3% generating the following hypothesis: perinatal asphyxia must be the principal direct and indirect etiologic factor (aggravating the expression of prematurity and infection diseases), of prenatal and perinatal mortality among newborns with white brain matter lesions; and <7 Apgar score in the 5th minute associated to brain white matter lesions, are markers for perinatal asphyxia diagnosis.
Estudo da resposta tissular à endoprótese recoberta de jugular bovina em veia cava inferior de suínos
Authors: Pinto Cristina Ribeiro Riguetti , Chouin Celso Luiz Muhlethaler , Espinosa Lopez Gaudencio
Published: September 2006

OBJETIVO: Avaliar a resposta tissular a uma endoprótese, com cobertura biológica heteróloga, implantada em veia cava inferior de suínos. MÉTODO: Desenvolvemos uma endoprótese auto-expansível, revestida com um segmento de jugular bovina, conservada por processo L-hydro e suturada em um stent de aço inoxidável 316L. O dispositivo introdutor utilizado foi a bainha de liberação da endoprótese aórtica Taheri-Leonhardt (Flórida, EUA). Foram implantadas endopróteses em 10 suínos, todas na veia cava infra-renal. Os animais foram submetidos à flebografia peroperatória. À necropsia, após 2 meses, cada endoprótese foi retirada em bloco e analisada macroscopicamente, visando a avaliação da perviedade, aderência aos tecidos vizinhos e incorporação à parede venosa; e, histopatologicamente, visando a resposta histológica ao enxerto. RESULTADOS: Na análise macroscópica, todas as endopróteses encontravam-se pérvias e totalmente incorporadas à parede venosa, porém seis apresentavam trabeculações grosseiras no seu interior e quatro algum grau de fibrose perivascular. Três animais desenvolveram linfocele, uma retroperitoneal e as outras na parede abdominal. No estudo histopatológico, observamos reação inflamatória granulomatosa tipo corpo estranho em todos os casos, sendo predominante na camada média (80%). CONCLUSÃO: O modelo estudado apresentou baixa trombogenicidade, corroborando com a eficácia do meio de conservação e material escolhidos; porém, baixa biocompatibilidade, provavelmente pelo obstáculo imunológico dos xenoenxertos e resposta tissular exagerada do território venoso.
Tratamento cirúrgico dos aneurismas da aorta abdominal: existe diferença dos resultados entre homens e mulheres?
Authors: Bonamigo Telmo Pedro , Lucas Márcio Luís , Erling Jr. Nilon
Published: September 2006

OBJETIVO: Avaliar os resultados cirúrgicos após o tratamento convencional e eletivo do aneurisma da aorta abdominal, verificando se existe diferença entre homens e mulheres na mortalidade e morbidade cirúrgicas, bem como nos resultados a longo prazo. PACIENTES E MÉTODOS: Entre dezembro de 1983 e dezembro de 2003, 675 pacientes foram submetidos ao tratamento cirúrgico do aneurisma da aorta abdominal infra-renal, sendo divididos em dois grupos: homens (n = 575) e mulheres (n = 100). Os dados demográficos e aqueles relacionados ao procedimento cirúrgico, bem como os resultados perioperatórios, foram coletados pela revisão dos prontuários. Os pacientes com alta hospitalar formaram uma coorte retrospectiva, onde foram avaliadas as causas tardias de óbito e a sobrevida. RESULTADOS: A média das idades foi similar, sem diferença estatística entre mulheres e homens (68,9 ± 9,1 versus 67,4 ± 7,1 anos; P = 0,089). A presença de hipertensão arterial foi significativamente superior nas mulheres (73 versus 62,4%; P = 0,042), e a cardiopatia isquêmica e história de tabagismo foram mais freqüentes nos homens (P <0,05). A mortalidade operatória total foi de 2,8%, não havendo diferença significativa entre mulheres e homens (4 versus 2,6%, respectivamente; P = 0,43). A morbidade cirúrgica envolveu 14% dos pacientes femininos e 18,4% dos masculinos (P 0,05). A taxa de sobrevida global em 1, 3, 5 e 10 anos não diferiu entre os grupos, sendo a sobrevida em 5 anos de 71% para as mulheres e 72% para os homens (P 0,05). A principal causa de morte tardia foi de origem cardiovascular, seguida de complicações renais nas mulheres e neoplasia nos homens. CONCLUSÂO: A taxa de mortalidade e morbidade cirúrgicas não aumentou significativamente nas mulheres após a correção eletiva do aneurisma da aorta abdominal infra-renal. Além disso, os resultados a longo prazo são semelhantes entre os dois gêneros.
Tratamento cirúrgico da "síndrome do roubo" em acesso vascular para hemodiálise com revascularização distal e ligadura arterial
Authors: Linardi Fábio , Linardi Felipe de Francisco , Bevilacqua José Luis , Morad José Francisco Moron , Costa José Augusto
Published: September 2006

OBJETIVO: O propósito do trabalho é apresentar o resultado do tratamento da "síndrome do roubo", sintomática em acesso vascular para hemodiálise, utilizando a técnica da revascularização distal com ligadura arterial. PACIENTES E MÉTODOS: No período de dezembro de 2003 a novembro de 2004, quatro pacientes que apresentaram síndrome do roubo sintomática em acesso vascular para hemodiálise foram submetidos à revascularização distal com ligadura arterial e acompanhados até dezembro de 2005. Os quatro pacientes apresentavam dor de repouso, e dois casos evoluíram para lesão trófica. RESULTADOS: Todos os casos apresentaram regressão dos sintomas, com cicatrização das lesões tróficas e manutenção do acesso vascular, que continuou sendo utilizado para realização de sessões de hemodiálise. CONCLUSÕES: Concluímos que, atualmente, o tratamento de escolha da síndrome do roubo sintomática é a revascularização distal com ligadura arterial, pois, além de tratar a isquemia do membro, mantém o acesso vascular funcionante.
Aneurisma de artéria poplítea com rotura e formação de pseudo-aneurisma
Authors: Barbato Heraldo Antônio , Cunha Marcelo Tavares , Clauzo Alexandre Volpini , Petisco Ana Cláudia Gomes , Rossi Fabio Henrique , Malheiros Fernando Dagli , Oliveira Lannes Alberto Vasconcelos , Izukawa Nilo Mitsuru
Published: September 2006

Paciente relatava história aguda de dor e edema em membro inferior direito há 5 dias, e a semiologia caracterizava pulsos poplíteos amplos e perfusão distal satisfatória. Exames laboratoriais mostraram insuficiência renal, e o exame de ultra-som duplex evidenciou um aneurisma de artéria poplítea à direita roto, com formação de pseudo-aneurisma e um aneurisma de artéria poplítea à esquerda. O paciente foi submetido à exploração cirúrgica por via de acesso posterior, sendo evidenciado pseudo-aneurisma secundário a aneurisma de artéria poplítea roto e realizada endoaneurismorrafia com interposição de veia. A evolução pós-operatória foi boa. A ruptura de um aneurisma de artéria poplítea é uma complicação rara, e apenas um relato de formação espontânea de pseudo-aneurisma foi encontrado na literatura.
Tratamento endovascular de pseudo-aneurisma da artéria subclávia em criança hemofílica
Authors: Silva Emanuella Galvão de Sales e , Moreira Ricardo Wagner da Costa , Arcenio Neto Elias , Silva Camila de Campos , Zurstrassen Charles Edouard , Ribeiro Flávio Roberto Cavalleiro de Macedo , Barros Orlando da Costa , Burihan Marcelo Calil , Nasser Felipe , Ingrund José Carlos , Neser Adnan
Published: September 2006

O uso de cateteres venosos centrais em pacientes hemofílicos é muito freqüente, devido às próprias características terapêuticas da doença. As complicações desses procedimentos, tais como pseudo-aneurisma, geralmente são mais graves nesses pacientes. A correção cirúrgica do pseudo-aneurisma que acomete a artéria subclávia constitui um dos maiores desafios da cirurgia vascular. Em pacientes hemofílicos, à dificuldade habitual de exposição cirúrgica somam-se os problemas de alteração no processo normal de coagulação. Como alternativa ao tratamento cirúrgico convencional, a utilização de técnicas endovasculares constitui uma solução segura e com bons resultados.
Silicose
Authors: Terra Filho Mario , Santos Ubiratan de Paula
Published: September 2006

Os autores apresentam uma revisão da literatura nacional e internacional e discutem aspectos epidemiológicos, fisiopatológicos, funcionais e do diagnóstico da silicose. São revistas a classificação clínica, as formas de tratamento e outras doenças sílico relacionadas, como a tuberculose, o câncer de pulmão e a esclerodermia. Aspectos preventivos e médico-legais também são discutidos.
Avaliação da disfunção e da incapacidade nas pneumoconioses
Authors: Neder José Alberto , Bagatin Ericson , Nery Luiz Eduardo
Published: September 2006

A determinaçâo das conseqüências funcionais (disfunção) e do seu impacto na vida diária (incapacidade) são aspectos centrais da avalição de pacientes com doença ocupacional respiratória. A presente revisão apresenta as bases fundamentais para o entendimento dos instrumentos utilizados para a definição do grau de disfunção, incluindo aspectos clínicos, funcionais pulmonares e, em algumas circunstâncias, da capacidade de exercício. Em especial, apresenta-se uma classificação multifatorial do grau de disfunção com o intuito de nortear a concessão ou não de benefícios previdenciários em nosso meio.
Diagnósticos histopatológicos das pneumoconioses
Authors: Capelozzi Vera Luiza , Saldiva Paulo Hilário Nascimento
Published: September 2006

As doenças asbesto-induzidas constituem um grave problema de saúde em decorrência de um grande número de trabalhadores expostos ao asbesto ao longo dos últimos 50 anos. Processos judiciais contra indústrias que lidam com asbesto somam centenas, com crescente adição de novos casos. O assunto relativo à asbestose é complexo, e muito embora a história natural das doenças induzidas esteja bem estabelecida, muitas áreas importantes, como a patologia, permanecem ainda pouco compreendidas. No Brasil, desde 1940, o asbesto é explorado comercialmente, sendo que nos últimos anos sua produção é da ordem de 200.000 toneladas por ano, estimando-se que na atividade de mineração cerca de 10.000 trabalhadores foram expostos a essa fibra, desconhecendo-se a estimativa do número de pessoas expostas na produção de fibrocimento, especialmente telhas e caixas d'água. Um estudo, de cunho inter-institucional, com metodologia de investigação científica apropriada, para avaliar as repercussões sobre a saúde dos trabalhadores nas minas de asbesto, em nosso país foi elaborado e intitulado "Moralidade e Mortalidade Entre Trabalhadores Expostos ao Asbesto na Atividade de Mineração 1940-1996". O objetivo deste trabalho foi fornecer uma visão ampla das doenças asbesto-induzida, com ênfase às dificuldades no diagnóstico histopatológico, através da experiência adquirida com o desenrolar desse projeto.
Modeling site-specific wild oat (Avena fatua) emergence across a variable landscape
Authors: Page Eric R. , Gallagher Robert S. , Kemanian Armen R. , Zhang Hao , Fuerst E. Patrick
Published: September 2006

The spatial and temporal pattern of wild oat emergence in eastern Washington is affected by the steep, rolling hills that dominate this landscape. The objective of this study was to assess the impact of landscape position and crop residue on the emergence phenology of wild oat. Emergence of a natural wild oat infestation was characterized over two growing seasons (2003 and 2004), at two wheat residue levels (0 and 500 g m−2), and at five landscape positions differing in slope, aspect, and elevation in a no-till winter wheat field. Wild oat emerged 1 to 2 wk earlier at south-facing landscape positions than at north-facing landscape positions. Crop residue delayed wild oat emergence by 7 to 13 d relative to bare soil at south-facing positions in 2003 and had a reduced effect on emergence at north-facing landscape positions. Therefore, preserving surface residues tended to synchronize emergence across the landscape and may facilitate better timing of weed control where residue is present. Emergence of wild oat was modeled as a function of thermal time adjusted by water potential using a Weibull function. Temperature explained more variation in the model than water potential. This model explained much of the variability in wild oat emergence among landscape positions over these 2 yr and may be useful as a tool to predict the timing of wild oat emergence. Results also indicate that site-specific modeling is a plausible approach to improving prediction of weed seedling emergence.
Influence of relative time of emergence on nitrogen responses of corn and velvetleaf
Authors: Harbur Matthew M. , Owen Micheal D. K.
Published: September 2006

Nitrogen (N) management markedly affects weed competition with crops. The effect of N availability on plant competition varies with a plant's abilities to capture and use N. Accordingly, we expected the N effect on plant competition to change with the relative emergence time of competing individuals. This hypothesis was tested by growing corn and velvetleaf plants in target and neighbor roles and comparing their N responses. Sowing times were varied, so that target plant emergent dates were constant, whereas neighbor plants were sown to emerge 7 d before, with, or 7 d after targets. Seedlings were fertilized daily with 2.5 mmol (“low N”) or 10.0 mmol (“high N”) ammonium nitrate (NH4NO3). Corn had greater total weight, leaf area, and root-to-shoot ratio (RSR) than velvetleaf. Different dry weights may have reflected seed weights; corn seed weight was greater than velvetleaf. Regardless of role, corn and velvetleaf dry weight and leaf area were greater with high N than low N; in contrast, RSR was lower with high N than low N. The RSR response to N availability suggested plant resources were shifted from N foraging, toward competition for photosynthetically active radiation (PAR). In target plants of each species, dry weight and leaf area increased linearly with time between target and neighbor emergence. Conversely, dry weight and leaf area of neighbor plants decreased with time between target and neighbor emergence. The N response of neighbor plants increased with time of emergence between target and neighbor emergence. Larger plants likely required more N to sustain growth than smaller plants; plants that emerged earlier likely had greater daily N requirements than those that emerged later. These results support factoring in emergence when predicting N effects on plant competition. Optimal N provisioning for integrated weed management may differ with emergence times of competing plants.
Planting date influences critical period of weed control in sweet corn
Authors: Williams Martin M.
Published: September 2006

The critical period for weed control (CPWC) identifies the phase of the crop growth cycle when weed interference results in unacceptable yield losses; however, the effect of planting date on CPWC is not well understood. Field studies were conducted in 2004 and 2005 at Urbana, IL, to determine CPWC in sweet corn for early May (EARLY) and late-June (LATE) planting dates. A quantitative series of treatments of both increasing duration of interference and length of weed-free period were imposed within each planting-date main plot. The beginning and end of the CPWC, based on 5% loss of marketable ear mass, was determined by fitting logistic and Gompertz equations to the relative yield data representing increasing duration of weed interference and weed-free periods, respectively. Weed interference stressed the crop more quickly and to a greater extent in EARLY, relative to LATE. At a 5% yield-loss level, duration of weed interference for 160 and 662 growing-degree days (GDD) from crop emergence marked the beginning of the CPWC for EARLY and LATE, respectively. When maintained weed-free for 320 and 134 GDD, weeds emerging later caused yield losses of less than 5% for EARLY and LATE, respectively. Weed densities exceeded 85 plants m−2for the duration of the experiments and predominant species included barnyardgrass, common lambsquarters, common purslane, redroot pigweed, and velvetleaf. Weed canopy height and total aboveground weed biomass were 300% and 500% higher, respectively, for EARLY compared with LATE. Interactions between planting date and CPWC indicate the need to consider planting date in the optimization of integrated weed management systems for sweet corn. In this study, weed management in mid-June–planted sweet corn could have been less intensive than early May–planted corn, reducing herbicide use and risk of herbicide carryover to sensitive rotation crops.
Factors affecting germination of horseweed (Conyza canadensis)
Authors: Nandula Vijay K. , Eubank Thomas W. , Poston Daniel H. , Koger Clifford H. , Reddy Krishna N.
Published: September 2006

The influence of environmental factors on germination and emergence of horseweed was examined in growth chamber experiments. Germination was highest (61%) under 24/20 C day/night temperature under light. Horseweed seed germination was observed under both light (13 h photoperiod) and complete darkness (24 h), but germination under continuous darkness was only 0 to 15% compared with 0 to 61% under light. All other experiments were conducted under 24/20 C and 13-h light conditions. Germination was 19 to 36% over a pH range from 4 to 10, with a trend toward higher germination under neutral-to-alkaline conditions. Horseweed germination was > 20% at < 40 mM NaCl concentration and lowest (4%) at 160 mM NaCl. These data suggest that even at high soil salinity conditions, horseweed can germinate. Germination of horseweed decreased from 25% to 2% as osmotic potential increased from 0 (distilled water) to −0.8 MPa, indicating that germination can still occur under moderate water stress conditions. Horseweed seedling emergence was at its maximum on the soil surface, and no seedlings emerged from seeds placed at a depth of 0.5 cm or higher.
Effect of rust-causing pathogen (Puccinia thlaspeos) on auxin-like and cytokinin-like activity in dyer's woad (Isatis tinctoria)
Authors: Stirk Wendy A. , Thomson Sherman V. , van Staden Johannes
Published: September 2006

The rust pathogen,Puccinia thlaspeos, is used for biocontrol of dyer's woad. Rust infection results in chlorotic leaves and abnormal flower and seed production of this noxious weed during its second year of growth. Auxin-like and cytokinin-like activity of healthy and infected plants (roots, shoots, and leaves) were determined during different growth stages. These samples were analyzed by use of the mung-bean rooting bioassay (auxin-like activity) and the soybean-callus bioassay (cytokinin-like activity). Rooting activity in the mung-bean bioassay was significantly higher in the infected-root extracts from Harvest 1 (rosette stage) compared with the healthy-root extracts and significantly higher in the healthy-shoot extracts from Harvest 2 (bolting plants) compared with infected-shoot extracts. Infected plants collected during Harvest 1 had greatly reduced cytokinin-like activity in the roots, shoots, and leaves compared with the healthy plants. Cytokinin-like activity increased slightly in the infected plants collected in subsequent harvests, with the highest activity recorded in root extracts. The results suggest potential ways that the rust-causing fungal pathogen is able to influence some physiologic processes in dyer's woad and so affect its growth.
Factors affecting seed germination of annual sowthistle (Sonchus oleraceus) in southern Australia
Authors: Chauhan Bhagirath S. , Gill Gurjeet , Preston Christopher
Published: September 2006

Annual sowthistle has become more abundant under no-till systems in southern Australia. Increased knowledge of germination biology of annual sowthistle would facilitate development of effective weed control programs. The effects of environmental factors on germination and emergence of annual sowthistle seeds were examined in laboratory and field experiments. Seeds of annual sowthistle were able to germinate over a broad range of temperatures (25/15, 20/12, and 15/9 C day/night temperatures). Seed germination was favored by light; however, some germination occurred in the dark as well. Greater than 90% of seeds germinated at a low level of salinity (40 mM NaCl), and some seeds germinated even at 160 mM NaCl (7.5%). Germination decreased from 95% to 11% as osmotic potential increased from 0 to −0.6 MPa and was completely inhibited at osmotic potential greater than −0.6 MPa. Seed germination was greater than 90% over a pH range of 5 to 8, but declined to 77% at pH 10. Seedling emergence was the greatest (77%) for seeds present on the soil surface but declined with depth, and no seedlings emerged from a soil depth of 5 cm. In another experiment in which seeds were after-ripened at different depths in a field, seed decay was greater on the soil surface than at 2 or 5 cm depth. At the end of the growing season, there was a much greater persistence of buried seed (32 to 42%) than seeds present on the soil surface (8%). Greater persistence of buried seed could be due to dormancy enforced by dark in this species.
Production of Green Fluorescent Protein Transgenic Embryonic Stem Cells Using the GENSAT Bacterial Artificial Chromosome Library
Authors: Tomishima Mark J. , Hadjantonakis Anna-Katerina , Gong Shiaoching , Studer Lorenz
Published: September 2006

Transgenic green fluorescent protein (GFP) reporter embryonic stem (ES) cells are powerful tools for studying gene regulation and lineage choice during development. Here we present a rapid method for the generation of ES cells expressing GFP under the control of selected genes. Bacterial artificial chromosomes (BACs) from a previously constructed GFP transcriptional fusion library (Gene Expression Nervous System Atlas [GENSAT]) were modified for use in ES cells, and multiple BAC transgenic ES cell lines were generated. Specific GFP expression in transgenic cell lines was confirmed during neural differentiation marking neural stem cells, neuronal precursors, and glial progeny by Hes5, Dll1, and GFAP, respectively. GFP was dynamically regulated in ES cell progeny in response to soluble factors that inhibit Notch signaling and a factor that directs astroglial fate choice. Our protocols provide a simple and efficient strategy to utilize the whole GENSAT BAC library to create hundreds of novel fluorescent cell lines for use in ES cell biology.
Essential Roles of Sphingosine 1-Phosphate/S1P1 Receptor Axis in the Migration of Neural Stem Cells Toward a Site of Spinal Cord Injury
Authors: Kimura Atsushi , Ohmori Tsukasa , Ohkawa Ryunosuke , Madoiwa Seiji , Mimuro Jun , Murakami Takashi , Kobayashi Eiji , Hoshino Yuichi , Yatomi Yutaka , Sakata Yoichi
Published: September 2006

Neural stem/progenitor cells (NSPCs) migrate toward a damaged area of the central nervous system (CNS) for the purpose of limiting and/or repairing the damage. Although this migratory property of NSPCs could theoretically be exploited for cell-based therapeutics of CNS diseases, little is known of the mechanisms responsible for migratory responses of NSPCs. Here, we found that sphingosine 1-phosphate (Sph-1-P), a physiological lysophospholipid mediator, had a potent chemoattractant activity for NSPCs, in which, of Sph-1-P receptors, S1P1 was abundantly expressed. Sph-1-P-induced NSPC migration was inhibited by the pretreatment with pertussis toxin, Y-27632 (a Rho kinase inhibitor), and VPC23019 (a competitive inhibitor of S1P1 and S1P3). Sph-1-P does not act as intracellular mediator or in an autocrine manner, because [3H]sphingosine, incorporated into NSPCs, was mainly converted to ceramide and sphingomyeline intracellularly, and the stimulation-dependent formation and extracellular release of Sph-1-P were not observed. Further, Sph-1-P concentration in the spinal cord was significantly increased at 7 days after a contusion injury, due to accumulation of microglia and reactive astrocytes in the injured area. This locally increased Sph-1-P concentration contributed to the migration of in vivo transplanted NSPCs through its receptor S1P1, given that lentiviral transduction of NSPCs with a short hairpin RNA interference for S1P1 abolished in vivo NSPC migration toward the injured area. This is the first report to identify a physiological role for a lipid mediator in NSPC migration toward a pathological area of the CNS and further indicates that the Sph-1-P/S1P1 pathway may have therapeutic potential for CNS injuries.
Epicardial Cells of Human Adults Can Undergo an Epithelial-to-Mesenchymal Transition and Obtain Characteristics of Smooth Muscle Cells In Vitro
Authors: van Tuyn John , Atsma Douwe E. , Winter Elizabeth M. , van der Velde-van Dijke Ietje , Pijnappels Daniel A. , Bax Noortje A.M. , Knaän-Shanzer Shoshan , Gittenberger-de Groot Adriana C. , Poelmann Robert E. , van der Laarse Arnoud , van der Wall Ernst E. , Schalij Martin J. , de Vries Antoine A.F.
Published: September 2006

Myocardial and coronary development are both critically dependent on epicardial cells. During cardiomorphogenesis, a subset of epicardial cells undergoes an epithelial-to-mesenchymal transition (EMT) and invades the myocardium to differentiate into various cell types, including coronary smooth muscle cells and perivascular and cardiac interstitial fibroblasts. Our current knowledge of epicardial EMT and the ensuing epicardium-derived cells (EPDCs) comes primarily from studies of chick and mouse embryonic development. Due to the absence of an in vitro culture system, very little is known about human EPDCs. Here, we report for the first time the establishment of cultures of primary epicardial cells from human adults and describe their immunophenotype, transcriptome, transducibility, and differentiation potential in vitro. Changes in morphology and β-catenin staining pattern indicated that human epicardial cells spontaneously undergo EMT early during ex vivo culture. The surface antigen profile of the cells after EMT closely resembles that of subepithelial fibroblasts; however, only EPDCs express the cardiac marker genes GATA4 and cardiac troponin T. After infection with an adenovirus vector encoding the transcription factor myocardin or after treatment with transforming growth factor-β1 or bone morphogenetic protein-2, EPDCs obtain characteristics of smooth muscle cells. Moreover, EPDCs can undergo osteogenesis but fail to form adipocytes or endothelial cells in vitro. Cultured epicardial cells from human adults recapitulate at least part of the differentiation potential of their embryonic counterparts and represent an excellent model system to explore the biological properties and therapeutic potential of these cells.
Response to Phosphorus of Cranberry on High Phosphorus Testing Acid Sandy Soils
Authors: Parent L. E. , Marchand S.
Published: September 2006

The fertilized sand‐grown cranberry (Vaccinium macrocarponAiton cv. Stevens) could be at risk for water contamination by P during seasonal flooding and drainage, especially in high‐P soils. The P diagnosis is usually conducted from soil and tissue tests but should also include water‐extractable P (PW) as an environmental index. Although the Bray‐1 P (PBray1) test is the current test for cranberry soils, the Mehlich‐III (M‐III) test is now commonly used in Quebec and the mid‐Atlantic USA as an agri‐environmental index with specified thresholds. Our objective was to relate the (P/[Al+Fe])M‐IIImolar ratio to PWand PBray1and to evaluate this ratio against yield and tissue P responses to added P in high‐P sand‐grown cranberry crops. Fertilizer trials were conducted during the 2001 to 2004 period at rates of 0, 13, 26, and 39 kg P ha−1yr−1on permanent plots at five locations in central Quebec. The slope of the relationship between the (P/[Al+Fe])M‐IIImolar ratio (range: 0.024–0.094) and PBray1(60–235 mg P kg−1) was 0.0004 (R2= 0.92). There were significant site and year effects but no significant effect of added P on berry yield. There were significant linear effects of added P on tissue P concentration in the range of 0.9 to 1.4 g P kg−1but no critical value could be defined. The simulated (P/[Al+Fe])M‐IIIenvironmental threshold (9.7 mg PWkg−1) was 0.113. The (P/[Al+Fe])M‐IIImolar ratio could be used interchangeably with PBray1in Quebec sand‐grown cranberry crops but the provisionary environmental threshold must be ascertained from drainage water monitoring.
Shrinkage and Subsidence in a Marsh Soil
Authors: Bernard M. , Dudoignon P. , Chevallier C. , Pons Y.
Published: September 2006

Modeling the shrinkage and subsidence of soils is generally based on the laboratory shrinkage curves established from liquid state to shrinkage limit, rarely exhibited in situ. We studied the vertical behavior of clay‐dominant soils from the Marais de l'Ouest (France) in the 20 to 100% water content range. The consolidation states were quantified by recording profiles of wet density (γb) and gravimetric water content (W) down to the depth of 2.50 and 2.00 m in a sunflower (Helianthus annuus L.) field and a grassland, respectively. Under the evident surface consolidation, a paleosol was observed at 1.3‐m depth in the sunflower field. The W profiles show two superimposed layers: in the upper layer, W increased from the shrinkage limit (Ws) to the plasticity limit (Wp), the W profiles bounded by the wet and dry season profiles; in the subjacent layer (100% > W > Wp), the W profiles were quite constant. The depth of Wp marks the end of the downward progression of the shrinkage cracks. The properties of shrinkage were established through drying stages on intact samples. In the Ws to Wp domain, the linearity of the volume–water content relation allows the modeling of the interseasonal volumetric distribution of the macroporosity due to the shrinkage cracks. The preliminary model of porosity behavior proposed agrees with the two superimposed layers: the Ws to Wp domain characterized by isotropic shrinkage (shrinkage geometry factor r = 3), and the W > Wp domain characterized by subsidence only (r = 1).
No‐Till Corn/Soybean Systems Including Winter Cover Crops
Authors: Villamil M. B. , Bollero G. A. , Darmody R. G. , Simmons F. W. , Bullock D. G.
Published: September 2006

The use of winter cover crops (WCC) such as hairy vetch (Vicia villosa Roth) and cereal rye (Secale cereale L.), in a corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] rotation provides long‐term benefits that are generally overlooked. There is a particular lack of information regarding the effects of WCC on soil physical and chemical properties. The objective of this study was to assess the effects of four crop sequences (C/S, corn‐fallow/soybean‐fallow; C‐R/S‐R, corn‐rye/soybean‐rye; C‐R/S‐V, corn‐rye/soybean‐vetch; and C‐R/S‐VR, corn‐rye/soybean‐vetch and rye) under no‐till on several soil physical and chemical properties. Soil chemical properties included soil organic matter (SOM), pH, total nitrogen (TN), nitrates (NO3–N), and available phosphorus (P). The analyzed soil physical properties analyzed were: water‐aggregate stability (WAS), bulk density (Db), penetration resistance (PR), total porosity (TP), pore‐size distribution, water retention properties, and saturated hydraulic conductivity (Ksat). The experimental design was a split‐split‐plot where whole‐plot treatments (sampling period) had a Latin square design and subplot treatments (crop sequences) were arranged in a randomized complete block design with four replications. Compared with winter fallow, crop sequences that included WCC provided substantial benefits from the soil productivity standpoint. Specifically, the use of the C‐R/S‐V or C‐R/S‐VR increased SOM down to 30 cm. All WCC sequences improved WAS with increases of 9, 13, and 17% for C‐R/S‐R, C‐R/S‐V, and C‐R/S‐VR, respectively. Winter cover crop sequences reduced Db and PR of the soil surface and increased total and storage porosity along with plant available water. While the C‐R/S‐V sequence was the most effective in reducing soil NO3–N, the C‐R/S‐R sequence was the most effective in fixing soil P.
Drainage Flux Measurement and Errors Associated with Automatic Tension‐controlled Suction Plates
Authors: Morari Francesco
Published: September 2006

Automatic control of high tension soil solution samplers (suction lysimeters) in response to the surrounding soil matric potential has been proposed as a new method to reduce the convergence and divergence fluxes around the lysimeters. It is important to evaluate the instruments' performance with automatically regulated suction because the efficiency of the control and its effects on the flux volumes could vary with the surrounding soil matric potential. An automatic equilibrium tension lysimeter (AETL) system was developed composed of 16 small‐area (572 cm2) ceramic suction plates that were continuously kept in equilibrium by an automated control device. The automated control device consisted of a datalogger connected to electronic tensiometers and to an electric vacuum pump that was activated to regulate the ceramic plate suction. The system was evaluated by simulating its performance with the HYDRUS‐2D finite‐element model. The AETL system continuously kept the lysimeters' suction in equilibrium with the surrounding soil when the soil water matric potential head ranged from −306 to 0 cm H2O. Suction control was less effective during low drainage conditions (soil matric potential head less than −50 cm H2O), when it took more time to re‐equilibrate the pressure heads. However analysis of the variability of drainage and model simulations showed that incorrect suction control in drier conditions had a limited effect on the collected volumes. Suction was much better controlled when drainage flux was high, allowing a correct estimate of drainage. Automatic control of suction plates is a valuable tool for estimating drainage fluxes. Fine control of suction is needed when drainage flux is high because even the slight overapplication of suction, which is typically done during field experiments to overcome porous plate resistance and ensure that a sample is collected, could produce marked overestimation of water drainage (>30%).
Post‐Harvest Soil Nitrate in Irrigated Corn
Authors: Gehl Ronald J. , Schmidt John P. , Godsey Chad B. , Maddux Larry D. , Gordon W. Barney
Published: September 2006

Elevated post‐harvest soil NO3 is an indicator that N fertilizer was applied in excess of the amount required to obtain maximum corn (Zea mays L.) yield, and represents a quantifiable environmental risk if water percolates through the soil profile during the fallow season. The reliability of using post‐harvest soil NO3 as an indicator of NO3 leaching potential was considered for various field sites with similar soil characteristics and slightly variable rainfall conditions. Six N treatments (surface broadcast) included: (i) 300 and (ii) 250 kg N ha−1 applied at planting; (iii) 250 kg N ha−1 split‐applied at planting (1/2) and sidedress (1/2); (iv) 185 kg N ha−1 split‐applied at planting (1/3) and sidedress (2/3); (v) 125 kg N ha−1 split‐applied at planting (1/5) and sidedress (2/5, 2/5); and (vi) 0 kg N ha−1 At one site, N treatments were represented in each of two irrigation treatments: 1.0× (optimal) and 1.25× (125% optimal). Soil samples were collected in 30‐cm increments at preplant and post‐harvest to a 240‐cm depth. Sand content exceeded 0.8 g g−1 within the 240‐cm soil profile at every site except one; and distinct textural transitions were present within the soil profile at four sites. Maximum grain yield was obtained with <185 kg N ha−1 at every site in both years. When less than average water was received at those sites with distinct textural transition (silt and clay to sand) in the upper soil profile, post‐harvest soil NO3 for N rates > 180 kg N ha−1 often exceeded 60 kg N ha−1 within a 30‐cm sampling depth. When these same sites received additional rainfall, post‐harvest results indicated that NO3 had moved down the soil profile, past the textural transition, and perhaps beyond the 240‐cm depth. For those sites with uniformly high sand content (0–240 cm), few differences in post‐harvest NO3 could be attributed to the N treatments exceeding 185 kg N ha−1 Nitrate had probably moved beyond 240 cm by the end of the growing season. Slight differences in site characteristics (e.g., textural boundaries) can greatly influence conclusions derived from post‐harvest soil sampling regarding the risk of NO3 leaching.
Study of the grafting reaction of SnMe4 on the surface of ZSM‐5 zeolite
Authors: Zheng Ying , Wang Xu‐xu , Li Zhao‐hui , Fu Xian‐zhi , Wei Ke‐mei
Published: September 2006

The grafting reaction of tetramethyltin on the surface of ZSM‐5 zeolite (Si:Al = 55.0) was studied under vacuum conditions, and the chemical compositions, structure and properties of the resulting solid were characterized by in situ FTIR, ICP, XRD, XPS, UV–vis DRS, temperature programmed decomposition (TPD) and N2 adsorption. The results show that the reaction occurs on the surface of ZSM‐5 zeolite at 223 K without destroying the zeolite framework. The BET surface area and the pore volume of the zeolite decrease and the surface properties change; however, the microporous structure is retained during the reaction and post treatment. Copyright © 2006 John Wiley & Sons, Ltd.
Who will win Wimbledon? The recognition heuristic in predicting sports events
Authors: Serwe Sascha , Frings Christian
Published: September 2006

Goldstein and Gigerenzer (2002) described the recognition heuristic as a fast, frugal, and effective decision strategy. However, most studies concerning the recognition heuristic have been conducted in static domains, that is, in domains where it could plausibly be argued that relevant variables stay relatively constant. Yet the question is whether the heuristic would also work in dynamic environments where the quality of the actors rises and falls, such as in sports. We tested performance of the recognition heuristic in a dynamic environment and used it to predict the outcomes of tennis matches in Wimbledon 2003. Recognition data of amateur tennis players and laypeople was used to build recognition rankings. These rankings correlated with official rankings and led to at least as good predictions. Simulations of individual choices showed high recognition validities of both amateurs (0.73) and laypeople (0.67). In a second study the recognition heuristic correctly predicted 90% of actual individual choices. Overall, the recognition heuristic may be effectively generalized to dynamic environments. Copyright © 2006 John Wiley & Sons, Ltd.