bluuebunny/crossref_metadata_2025 huggingface dataset:
Preferência alimentar (entre sangue humano e ave) dos Triatoma sordida encontrados em casas habitadas da região norte do Estado de São Paulo - Brasil
Authors: Silva Eduardo Olavo da Rocha e , Souza José Maria Pacheco de , Andrade José Carlos Rehder de , Mello Cassio da Silva , Ferreira Octávio Alves
Published: May 2006

São apresentados os resultados dos testes de precipitina contra soro anti-sangue humano e anti-sangue ave, realizados com 550 exemplares do T. sordida, capturados nas casas habitadas das Regionais: Ribeirão Preto e São José do Rio Preto. A partir dos percentuais de positividade para sangue humano e de ave e da freqüência relativa dos vertebrados nas casas, levantaram-se os índices de seletividade hematofílica. Como observação complementar, montou-se, no laboratório, um sistema de oferta simultânea de sangue humano e ave à ninfas do 1º estádio, não alimentadas, testando-se 185 exemplares. Concluiu-se que o T. sordida, nas áreas consideradas, suga mais ave do que homem, mesmo quando encontrado em casas habitadas. Em conseqüência, comentam-se as possíveis implicações do fato com a transmissão da endemia chagásica ao homem e com as medidas de controle.
Epidemia de encefalite por arbovírus na região sul do Estado de São Paulo, Brasil, em 1975 e 1976: aspectos da distribuição cronológica e geográfica dos casos
Authors: Iversson Lygia Busch
Published: May 2006

Foi estudada a evolução de uma epidemia de encefalite por arbovirus do grupo B (flavivirus) em 20 municípios da região sul do Estado de São Paulo, Brasil, durante os anos de 1975 e 1976. Verificou-se que a moléstia se propagou em forma de onda epidêmica na direção leste-oeste e leste-sudoeste. A cadeia de montanhas situada ao norte e noroeste da região parece ter-se constituido em barreira à doença. Foi observada também variação estacional, com maior morbidade nos meses de verão e início do outono.
Crescimento da parte aérea de plantas cultivadas em vaso, submetidas à irrigação subsuperficial e a diferentes graus de compactação de um Latossolo Vermelho-Escuro distrófico
Authors: Silva Geovani José , Maia João Carlos de Souza , Bianchini Aloísio
Published: May 2006

A compactação é um processo que pode ocorrer em solos manejados inadequadamente, afetando, direta ou indiretamente, o crescimento e a produção das culturas. Com o objetivo de avaliar o crescimento da parte aérea de plantas, considerando os diferentes graus de compactação subsuperficial, plantas de soja, milho, algodão e Brachiaria brizantha foram cultivadas em vasos com material de um Latossolo Vermelho-Escuro distrófico, sob condição de fornecimento subsuperficial de água. O experimento foi realizado, sob telado, na Faculdade de Agronomia e Medicina Veterinária da UFMT, em vasos de PVC rígido de 195 mm de diâmetro interno, adotando-se delineamento inteiramente casualizado em esquema fatorial 4 x 4 x 5 (quatro espécies, densidades do solo de 1,0; 1,2; 1,4 e 1,5 Mg m-3 e cinco repetições). O conteúdo de água no sistema solo/vaso foi mantido acima de 60 % da capacidade de campo. Ao fim do experimento, mediu-se a altura das plantas, cortaram-se as plantas rente ao solo e foram determinadas a área foliar, a massa seca de frutificações (algodão, soja e milho) e a massa seca total da parte aérea. A compactação do solo provocou reduções significativas no crescimento da parte aérea do algodoeiro, milho e soja a partir de 1,4 Mg m-3 e na densidade do solo de 1,5 Mg m-3, para Brachiaria brizantha. A soja apresentou os maiores incrementos das características avaliadas na densidade do solo de 1,2 Mg m-3. A Brachiaria brizantha mostrou-se como a espécie de maior tolerância, enquanto o algodoeiro revelou maior susceptibilidade aos efeitos da compactação. Em geral, o modelo quadrático explicou adequadamente o crescimento das plantas de acordo com a compactação.
Coffee and gastric cancer: systematic review and meta-analysis
Authors: Botelho Francisco , Lunet Nuno , Barros Henrique
Published: May 2006

We systematically reviewed the literature on the association between coffee consumption and gastric cancer and performed a meta-analysis of the results. Published cohort and case-control studies were identified in PubMed and reference lists. Random effects meta-analysis was used to pool effects from 23 studies, and heterogeneity was explored by stratification and meta-regression. The odds ratio (OR) for the overall association between coffee and gastric cancer (highest vs. lowest category of exposure) was 0.97 (95%CI: 0.86-1.09), similar for cohort (OR = 1.02; 95%CI: 0.76-1.37) and case-control studies (population-based: OR = 0.90; 95%CI: 0.70-1.15; hospital-based: OR = 0.97; 95%CI: 0.83-1.13). The OR was 1.26 (95%CI: 1.02-1.57) when considering five studies conducted in the USA, 0.97 (95%CI: 0.82-1.14) for the five Japanese studies, 0.98 (95%CI: 0.81-1.17) for the six studies from Europe, and 0.64 (95%CI: 0.47-0.86) for the two studies from South America. In this meta-analysis we found no adverse effect of coffee associated with gastric cancer. Knowledge on the level of exposure to different coffee constituents may provide a deeper understanding of this reassuring result and the real role of coffee on cancer risk.
Perfil clínico-epidemiológico de pacientes com doença de Chagas no Hospital Universitário de Maringá, Paraná, Brasil
Authors: Bozelli Carlos Eduardo , Araújo Silvana Marques de , Guilherme Ana Lúcia Falavigna , Gomes Mônica Lúcia
Published: May 2006

Este trabalho descreveu o perfil clínico-epidemiológico de pacientes com doença de Chagas atendidos no ambulatório e na internação do Hospital Universitário de Maringá (HUM), Paraná, Brasil, entre maio de 1998 a maio de 2003. A média de idade foi maior no serviço de internação (p < 0,000). O sexo masculino predominou entre os internados e o feminino entre os ambulatoriais (p = 0,0033). De 95 pacientes, 60% nasceram em Minas Gerais e São Paulo e 25,3% no Paraná. A história familiar para doença de Chagas foi positiva em 68,9% deles e 53,3% relataram a presença de triatomíneos no domicílio. Em ordem decrescente ocorreram as formas clínicas cardíaca, digestiva, indeterminada e cardiodigestiva. A forma indeterminada prevaleceu entre os ambulatoriais e as formas cardíaca e digestiva entre os internados. As complicações crônicas cardíacas e digestivas foram as principais queixas para a internação. Destacam-se os altos percentuais de doença cardíaca (38,9%) e digestiva (26,3%) encontrados neste estudo, de forma distinta ao que acontece em outras regiões geográficas. O HUM disponibiliza o tratamento sintomático dessas complicações e não prioriza o tratamento etiológico mesmo para pacientes em fase indeterminada.
Prevalência e fatores associados à ocorrência da dor de dente que impediu a realização de tarefas habituais em uma população de funcionários públicos no Rio de Janeiro, Brasil
Authors: Alexandre Gisele Caldas , Nadanovsky Paulo , Lopes Claudia S. , Faerstein Eduardo
Published: May 2006

Nesse estudo, objetivou-se estimar a prevalência da dor de dente que impedisse a realização de tarefas habituais e testar sua associação com fatores sócio-econômicos, transtornos mentais comuns, número de dentes perdidos e padrão de visita ao dentista. Realizou-se estudo transversal, com questionário autopreenchível, aplicado em 4.030 funcionários de uma universidade no Rio de Janeiro, Brasil Estudo Pró-Saúde. As análises foram conduzidas por meio de regressão logística multivariada. A prevalência da dor de dente que impediu a realização de tarefas habituais, nas duas semanas que antecederam o preenchimento do questionário, foi de 2,9% (IC95%: 2,5-3,6). Ser do sexo masculino (OR = 1,6; IC95%: 1,1-2,4), apresentar transtorno mental comum (OR = 1,7; IC95%: 1,2-2,6), ter perdido muitos dentes (OR = 3,4; IC95%: 1,5-7,8) e não visitar o dentista para uma revisão de rotina (OR = 2,5; IC95%: 1,8-17,3), aumentaram a chance de ter tido dor de dente. A dor de dente foi um problema importante nessa população. Circunstâncias desfavoráveis de vida e não visitar o dentista para uma revisão de rotina aumentaram as chances de ter dor de dente.
Georges Canguilhem y el estatuto epistemológico del concepto de salud
Authors: Caponi Sandra
Published: May 2006

Tomando como punto de partida la discusión de Canguilhem relativa al estatuto epistemológico del concepto de salud, pretendemos problematizar las conceptualizaciones dada por la OMS y una definición ampliada enunciada por la VIII Conferencia Nacional de Salud que se han convertido hoy en hegemónicas. Esas conceptualizaciones entienden la salud como equilibrio y adaptación al medio. Nuestro objetivo fundamental es evidenciar que el ámbito de los enunciados está en permanente cruzamiento con el ámbito de lo no discursivo, de lo institucional. Siendo así, la aceptación de determinado concepto de salud implica el direccionamiento de determinadas políticas y de ciertas intervenciones efectivas sobre el cuerpo y la vida de los sujetos.
Comportamento subagudo da pressão arterial após o treinamento de força em hipertensos controlados
Authors: Mediano Mauro Felippe Felix , Paravidino Vitor , Simão Roberto , Pontes Francisco Luciano , Polito Marcos Doederlein
Published: May 2006

Diversos estudos têm demonstrado um efeito benéfico do exercício de força sobre a redução da pressão arterial (PA) pós-exercício, mas ainda são escassas as pesquisas envolvendo pessoas hipertensas. Dessa forma, o presente estudo tem como objetivo comparar as respostas de PA em sujeitos hipertensos medicados após duas sessões de exercício de força com diferentes volumes de treinamento. Para tal, foram estudados 20 indivíduos de ambos os gêneros (61 ± 12 anos) com hipertensão controlada por fármacos e participantes de um programa de exercícios, porém sem experiência no treinamento de força. O estudo foi realizado em três dias não consecutivos. Primeiramente, foi determinada a carga de 10 repetições máximas em cada exercício da seqüência (supino reto, leg-press horizontal, remada em pé e rosca tríceps). Nos demais dias, os mesmos exercícios foram realizados com uma (SER1) ou três (SER3) séries. A aferição da PA foi executada pelo método auscultatório no momento pré-exercício, imediatamente após o término de cada sessão e durante 60 minutos após o término dos exercícios. A ANOVA de medidas repetidas identificou que em ambas as sessões os valores da PA sistólica (PAS) e diastólica (PAD), medidos imediatamente após o término dos exercícios, foram mais elevados (p < 0,05) que os do pré-exercício. O acompanhamento em 60 minutos exibiu, após SER1, uma redução dos valores de PAS apenas no 40º minuto, enquanto não foram encontradas reduções para a PAD. Já após SER3, observou-se uma queda dos níveis de PAS que perdurou por todo o período de monitorização. Para PAD, foram encontradas reduções apenas no 30º e 50º minuto pós-exercício. Conclui-se que uma sessão de treinamento de força pode promover reduções nos níveis de PAS em indivíduos hipertensos medicados e parece ser necessário um maior volume de treinamento para que tal efeito ocorra.
Comportamento de variáveis fisiológicas em atletas de nado sincronizado durante uma sessão de treinamento na fase de preparação para as Olimpíadas de Atenas 2004
Authors: Pazikas Marina Guimarães Antunes , Curi Andréa , Aoki Marcelo Saldanha
Published: May 2006

O objetivo do presente estudo foi avaliar o comportamento de variáveis fisiológicas durante uma sessão de treino de nado sincronizado realizada na fase de preparação para as Olimpíadas de Atenas 2004. MATERIAIS E MÉTODOS: A amostra utilizada foi constituída pelo dueto (24 ± 0 anos) representante do Brasil em Atenas 2004. A coleta de dados foi realizada durante uma sessão de treinamento com duração de 198 minutos. O treino se iniciou com a parte física, seguida da parte técnica. Para a determinação da glicemia e da concentração de beta-hidroxibutirato foi utilizado o monitor Optium® com suas respectivas tiras. As concentrações de cortisol e das enzimas lactato desidrogenase (LDH) e creatina quinase (CK) foram determinadas por radioimunoensaio (DPC©) e kits comerciais (CELM®), respectivamente. O acompanhamento da freqüência cardíaca (FC) foi realizado com o freqüêncimetro Advantage Polar®. RESULTADOS: Foi observada redução (~2%) do peso corporal. A glicemia também apresentou queda (~30%) em comparação ao valor obtido no início do treino. Em contrapartida, foi observada elevação na concentração de cortisol (salivar 22% e plasmática 29%) e de beta-hidroxibutirato (~340%). Não foi observada alteração significativa na concentração plasmática de CK e de LDH. O acompanhamento da FC demonstrou que dos 198 minutos que constituíram a sessão de treino, 36,5 ± 0,7 minutos foram realizados em intensidade leve; 103,5 ± 0,7 minutos em intensidade moderada, 54,0 ± 2,1 minutos em intensidade alta e 4,0 ± 0,0 minutos em intensidade muito alta. CONCLUSÕES: A perda de peso indica que a reposição hídrica não foi adequada. A redução na glicemia e o aumento na concentração de corpos cetônicos e de cortisol reforçam a importância da suplementação de carboidrato durante o treino de longa duração. O comportamento da FC demonstra que a sessão de treinamento foi realizada em uma intensidade moderada, porém com breves momentos de intensidade alta, nos quais foram realizadas as rotinas.
Relação da síndrome do excesso de treinamento com estresse, fadiga e serotonina
Authors: Rohlfs Izabel Cristina Provenza de Miranda , Mara Lourenço Sampaio de , Lima Walter Celso de , Carvalho Tales de
Published: May 2006

A grande exigência do esporte competitivo tem provocado sérias conseqüências em atletas envolvidos em treinamento de alto nível. Por sua vez, a mudança dos padrões estéticos tem levado indivíduos a buscarem, por meio do exercício físico, a redução da massa corporal, o aumento da massa muscular e do condicionamento aeróbio. É comum atletas e não atletas excederem os limites de suas capacidades físicas e psicológicas ocasionando o desenvolvimento da síndrome do excesso de treinamento (overtraining), a qual é definida como um distúrbio neuroendócrino (hipotálamo-hipofisário) que resulta do desequilíbrio entre a demanda do exercício e a possibilidade de assimilação de treinamento, acarretando alterações metabólicas, com conseqüências que abrangem não apenas o desempenho, mas também outros aspectos fisiológicos e emocionais. Altos índices de estresse físico, sócio-cultural e psíquico são fatores que colaboram com o seu aparecimento, bem como alterações neuroendócrinas provocadas por aspectos nutricionais, que levam a flutuações serotoninérgicas. Alterações nos níveis de serotonina cerebral podem ser associadas ao aparecimento do estado de fadiga física, que pode se estabelecer de forma crônica, constituindo-se um dos sintomas do quadro. Deficiências ou desequilíbrios em neurotransmissores e neuromoduladores também podem ser causados por severo ou longo estresse. O objetivo do presente artigo de revisão é fazer uma análise dos fatores que contribuem de forma sinérgica para o aparecimento da síndrome do excesso de treinamento.
Relationship between the diameter of great saphenous vein and body mass index
Authors: Seidel Amélia C. , Miranda Jr. Fausto , Juliano Yara , Novo Neil F.
Published: May 2006

OBJECTIVE: This study has been designed to correlate the diameter of the greater saphenous vein in different levels of the lower limbs with the body mass index of each individual to determine a possible relation between them. METHODS: Fifty-two lower limbs in 26 volunteers (six males and 20 females) without a chronic venous disease record, aged 21-68 were evaluated. Prior to color-flow duplex scanning the body mass index was defined. The deep and superficial venous systems and perforator veins were assessed as described in the literature. The diameter of the greater saphenous vein was measured with ultrasound longitudinal imaging in seven different levels. For the statistical analysis, Student t test for paired data and Spearman test were used. RESULTS: The difference observed in saphenous venous in the second and third levels when compared to the lower right and left limbs was not considered significant and a single group was formed to correlate with body mass index. The correlation was considered statistically irrelevant. CONCLUSION: By correlating the diameters of the greater saphenous vein with the body mass index of each individual it was noted that the relation between them is not significant, therefore it can be assumed that tall thin individuals can have greater saphenous vein with similar diameter as short fat individuals.
O papel do mapeamento dúplex no diagnóstico da trombose venosa profunda assintomática dos membros inferiores
Authors: Giannini Mariangela , Rollo Hamilton Almeida , Maffei Francisco Humberto de Abreu
Published: May 2006

O diagnóstico da trombose venosa profunda sintomática está bem estabelecido com o uso do mapeamento dúplex, que apresenta sensibilidade de 100% e especificidade de 98%, para trombose venosa profunda proximal, e sensibilidade de 94% e especificidade de 75%, para distal. Na trombose venosa profunda recente e assintomática, o diagnóstico com o mapeamento dúplex ainda não está bem estabelecido, mostrando uma queda na acurácia desse método diagnóstico. Essa queda é devida ao fato de o trombo recente não ser oclusivo, apresentar a mesma ecogenicidade do sangue e uma consistência diminuída, prejudicando o teste da compressibilidade, que é o mais sensível para diagnóstico da trombose venosa profunda. Nesta revisão, serão revistos artigos publicados que avaliaram a acurácia do mapeamento dúplex no diagnóstico da trombose venosa profunda assintomática.
A terapia celular no tratamento da isquemia crítica dos membros inferiores
Authors: Araújo José Dalmo de , Araújo Filho José Dalmo de , Ciorlin Emerson , Ruiz Milton Artur , Ruiz Lílian Piron , Greco Oswaldo Tadeu , Lago Mario Roberto , Ardito Roberto Vito
Published: May 2006

Os autores fazem um histórico sobre as pesquisas com células-tronco embrionárias e do cordão umbilical, suas respectivas vantagens e desvantagens. Seguem com as discussões sobre células-tronco adultas, sua definição, histórico, fontes e participação nos processos de regeneração tecidual, particularmente no endotélio. Ressaltam a importância de fatores que mobilizam as células-tronco adultas a partir da medula óssea: citocinas, angiopoietinas e outros fatores de crescimento. As células-tronco adultas mobilizam-se sob a forma de células endoteliais progenitoras, que têm origem comum com as células endoteliais a partir dos hemangioblastos. Os fatores de mobilização manifestam-se em condições de hipoxia e fazem com que as células endoteliais progenitoras se localizem nos locais de isquemia para produzir a neovasculogênese, que se faz por três possíveis mecanismos: a angiogênese (formação de novos capilares a partir de brotos de capilares já existentes), a arteriogênese (relacionada à circulação colateral) e a vasculogênese (vasos realmente novos). Fazem, a seguir, uma análise da literatura relativa à experimentação animal e aos estudos clínicos. Concluem ressaltando que as células-tronco adultas, embora tenham um grande potencial de uso, ainda demandam muito estudo e pesquisa para se firmar como método terapêutico.
A Bayesian belief network model of bridge deterioration
Authors: Attoh-Okine N. O. , Bowers S.
Published: May 2006

Bridge deterioration is a major component in making bridge management decisions. It is obvious that the deterioration of one bridge element may accelerate the overall deterioration of a bridge. Current studies, although very promising, fail to address interaction among bridge elements in an effective manner. Fault tree modelling has been advocated as one of the methods that effectively handle the issue of bridge element interaction. Fault tree analysis, however, is well suited for catastrophic failure, which is uncommon in bridge deterioration. As an alternative to fault trees, belief networks are more appropriate for modelling the long-term deterioration that is typically characteristic of bridges. This paper develops a new deterioration modelling procedure based on belief networks. Belief networks effectively capture and illustrate the hierarchical, interaction, and uncertainty factors present in the bridge deterioration process. An example belief network deterioration model is presented and used to address ‘what if’ issues that are characteristic of any bridge maintenance and management process.
Junctional Epithelium in Rats Is Characterized by Slow Cell Proliferation
Authors: Willberg Jaana , Syrjänen Stina , Hormia Marketta
Published: May 2006

Background: The integrity of junctional epithelium (JE) and a firm epithelial adhesion to the tooth surface are maintained by the balance between cell proliferation and cell death. Maintaining the JE structure is essential for the protection of periodontal connective tissues against oral microbes. In this study, the proliferative activity and the expression of caspase 3, a cysteine protease associated with cell death, were studied in rat JE and other epithelial structures during molar tooth development.

Methods: Fourteen rats aged 10 to 70 days were injected with bromodeoxyuridine (BrdU). Samples of first and second molars were selected for immunohistochemical staining. BrdU incorporation was studied in oral epithelium (OE) covering the erupting tooth, reduced enamel epithelium (REE), and gingival epithelium (GE), sulcular epithelium (SE), and JE. Samples were also subjected to immunohistochemical analysis for proliferating cell nuclear antigen (PCNA) and caspase 3.

Results: The basal cells of the GE were actively proliferating, but in the JE, only a few cells were positive for BrdU or PCNA immunostaining. Some outer REE cells were proliferating during tooth eruption. Caspase 3 expression was in specific areas of REE after completion of amelogenesis.

Conclusions: Results showed slow proliferative activity in the rat JE. However, specific studies on cellular turnover and cell migration are needed to understand tissue homeostasis in this area.
Chlorophyll Meter Readings Can Predict Nitrogen Need and Yield Response of Corn in the North‐Central USA
Authors: Scharf Peter C. , Brouder Sylvie M. , Hoeft Robert G.
Published: May 2006

Nitrogen fertilizer is a fundamental input for production of corn (Zea mays L.) that can move to ground and surface waters when over‐applied. Previous research has shown that chlorophyll meter (CM) readings can indicate N stress in corn, but has not addressed whether the amount of N needed can be predicted by CM readings. Our objective was to evaluate whether CM readings can predict corn N need and yield response to N. Sixty‐six N rate experiments were conducted in seven north‐central states over a 4‐yr period. Linear regression was used to relate absolute and relative CM readings over a range of growth stages to economically optimal N rate (EONR) and yield response to N applied at growth stage V7 or earlier. Chlorophyll meter readings at all growth stages from V5 to R5 were significantly related (P < 0.0001 in 22 of 24 models, P < 0.01 in 2 models) to EONR and yield response to N. Relationships were stronger for relative than for than absolute CM readings, and also were stronger when the corn had received no N fertilizer at planting. Coefficients of determination ranged from 0.53 to 0.76 for relative CM reading as a predictor of EONR or yield response to N, and were lower for the V5 to V9 stage than for later stages. Earlier research has indicated that measurements with this level of predictive accuracy can produce N rate recommendations that are more profitable than current N management practices. Our findings suggest that CM readings (and potentially other measures of corn color) are quantitatively related to early‐season EONR and yield response to N over a wide range of environments with enough accuracy to be helpful in making management decisions.
Soil Tests for Predicting Corn Response to Nitrogen Fertilizer in New York
Authors: Klapwyk Jonathan H. , Ketterings Quirine M.
Published: May 2006

The presidedress nitrate test (PSNT) is currently the best tool available for Northeastern producers to determine if corn (Zea mays L.) will benefit from sidedress N. The PSNT requires 0‐ to 30‐cm soil samples, which can be difficult to obtain on stony soils, and samples need to be taken in late‐spring, an inopportune time for dairy (Bos taurus) farmers. Additionally, the in‐season nature of the PSNT prevents its use by producers who apply preplant broadcast N. The Illinois soil N test (ISNT) is a simple test that estimates a potentially mineralizable fraction of soil organic N, amino sugar N. The test was able to identify sites that are nonresponsive to sidedress N fertilization in Illinois. From 2002 to 2004, 33 field trials were conducted to assess the effectiveness of the ISNT as compared with the PSNT in New York. Results confirmed the ability of the PSNT to separate responsive from nonresponsive corn sites. The ISNT was not an effective predictor by itself. However, when ISNT results and soil organic matter (OM) were considered, critical values could be developed that separated fields that were responsive to sidedress N from nonresponsive sites for corn silage dry matter yield, N concentration, N uptake, and estimated milk yield (kg of milk per ha predicted based on yield and quality of the silage). Further evaluation of the ISNT with consideration for OM could improve the accessibility of soil N testing to corn producers who apply N as sidedress as well as those who fertilize with preplant broadcast applications in the Northeast.
Spring Yield and Silage Characteristics of Kura Clover, Winter Wheat, and in Mixtures
Authors: Contreras‐Govea Francisco E. , Albrecht Kenneth A. , Muck Richard E.
Published: May 2006

Kura clover (Trifolium ambiguum M. Bieb.) grown in monoculture is difficult to harvest mechanically because of its decumbent growth habit, and legumes in general have poor ensiling characteristics. Our objectives were to assess forage yield, nutritive value, and silage characteristics of kura clover–winter wheat (Triticum aestivum L.) mixtures to determine usefulness as a silage crop. ‘Cardinal’ winter wheat was sown in monoculture and into an ‘Endura’ kura clover sward in autumn at two locations and in 2 yr, and harvested at wheat boot and milk stages the following spring. Sole kura clover was harvested at the same time as winter wheat and mixtures. In addition, two mixtures of kura clover with winter wheat were created at each harvest by blending desired proportions from crops grown in monoculture. The mixture of kura clover with winter wheat yielded 7.4 Mg dry matter (DM) ha−1 while sole kura clover yielded 3.4 Mg DM ha−1 and sole winter wheat 9.05 Mg DM ha−1 However, kura clover yield in the binary mixture was similar to sole kura clover. Neutral detergent fiber and acid detergent fiber concentrations were lower in kura clover than winter wheat and intermediate in mixtures. Fermented mixtures had similar pH to sole winter wheat (pH 3.8) and lower than sole kura clover (pH 4.1). The proportion of total N recovered as nonprotein N in silage was 9% lower in kura clover and in mixtures than in winter wheat. Water‐soluble carbohydrate (WSC) concentrations of wilted forage were higher in mixtures than sole kura clover (157 vs. 105 g kg−1 DM), and mixtures had lower WSC than sole winter wheat (198 g kg−1 DM). Lactate concentration was 13% higher in silage from mixtures than sole kura clover. Spring forage production of kura clover–winter wheat mixtures was greater than sole kura clover, possessed adequate nutritive value for high‐producing livestock, and mixture silage characteristics were better than sole kura clover.
Interference of Instrumental Instruction in Subsequent Relational Learning
Authors: Pesek Dolores D. , Kirshner David
Published: May 2006

To balance their professional obligation to teach for understanding against administrators' push for higher standardized test scores, mathematics teachers sometimes adopt a 2-track strategy: teach part of the time for meaning (relational learning) and part of the time for recall and procedural- skill development (instrumental learning). We explore a possible negative effect of this dual approach when relational learning is preceded by instrumental learning. A group of students who received only relational instruction outperformed a group of students who received instrumental instruction prior to relational instruction. Interview data show aspects of cognitive, metacognitive, and attitudinal interference that may have been caused by the juxtaposition of instructional modes.
A Calculus Graphing Schema
Authors: Baker Bernadette , Cooley Laurel , Trigueros María
Published: May 2006

In this study, we analyzed students' understanding of a complex calculus graphing problem. Students were asked to sketch the graph of a function, given its analytic properties (1st and 2nd derivatives, limits, and continuity) on specific intervals of the domain. The triad of schema development in the context of APOS theory was utilized to study students' responses. Two dimensions of understanding emerged, 1 involving properties and the other involving intervals. A student's coordination of the 2 dimensions is referred to as that student's overall calculus graphing schema. Additionally, a number of conceptual problems were consistently demonstrated by students throughout the study, and these difficulties are discussed in some detail.
Making Sense of the Total of Two Dice
Authors: Pratt Dave
Published: May 2006

Many studies have shown that the strategies used in making judgments of chance are subject to systematic bias. Concerning chance and randomness, little is known about the relationship between the external structuring resources, made available for example in a pedagogic environment, and the construction of new internal resources. In this study I used a novel approach in which young children articulated their meanings for chance through their attempts to “mend” possibly broken computer-based stochastic gadgets. I describe the interplay between informal intuitions and computer-based resources as the children constructed new internal resources for making sense of the total of 2 spinners and 2 dice.
Characterization and comparison of polyurethane networks prepared using soybean‐based polyols with varying hydroxyl content and their blends with petroleum‐based polyols
Authors: Pechar T. W. , Sohn S. , Wilkes G. L. , Ghosh S. , Frazier C. E. , Fornof A. , Long T. E.
Published: May 2006

Polyurethane Networks (PUNs) were synthesized using polyols derived from soybean oil, petroleum, or a blend of the two in conjunction with diisocyanate. The soybean‐based polyols (SBPs) were prepared using air oxidation, or by hydroxylating epoxidized soybean oil. Some of the networks were subjected to several solvents to determine their respective swelling behavior and solubility parameters. Sol‐fractions were also determined, and DMA experiments were utilized to monitor the changes in storage modulus and tan δ with temperature for networks with sol and with the sol extracted. A linear relationship was noted between the hydroxyl number of a SBP and the glass transition temperature of its corresponding unextracted PU network within the range of hydroxyl numbers (i.e., 55–237 mg KOH/g) and glass transition temperatures (i.e., −21–+83°C) encountered in this work. This same linear relationship was realized between the weighted hydroxyl number of soy and petroleum‐based polyol blends and the glass transition temperature of the resulting unextracted and extracted network PUs within the ranges utilized in this study (i.e., 44–57 mg KOH/g, −54–19°C). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1432–1443, 2006
RNA interference of sialidase improves glycoprotein sialic acid content consistency
Authors: Ngantung Frederyk A. , Miller Peter G. , Brushett Fikile R. , Tang Goh Lin , Wang Daniel I.C.
Published: May 2006

An important challenge facing therapeutic protein production in mammalian cell culture is the cleavage of terminal sialic acids on recombinant protein glycans by the glycosidase enzymes released by lysed cells into the supernatant. This undesired phenomenon results in a protein product which is rapidly cleared from the plasma by asialoglycoprotein receptors in the liver. In this study, RNA interference was utilized as a genetic approach to silence the activity of sialidase, a glycosidase responsible for cleaving terminal sialic acids on IFN‐γ produced by Chinese Hamster Ovary (CHO) cells. We first identified a 21‐nt double stranded siRNA that reduced endogenous sialidase mRNA and protein activity levels. Potency of each siRNA sequences was compared using real time RT‐PCR and a sialidase activity assay. We next integrated the siRNA sequence into CHO cells, allowing production and selection of stable cell lines. We isolated stable clones with sialidase activity reduced by over 60% as compared to the control cell line. Micellar electrokinetic chromatography (MEKC), thiobarbituric acid assay (TAA), and high performance anion exchange chromatography (HPAEC) coupled to amperometric detection were performed to analyze glycan site occupancy, sialic acid content, and distribution of asialo‐/sialylated‐glycan structures, respectively. Two of the stable clones successfully retained the full sialic acid content of the recombinant IFN‐γ, even upon cells' death. This was comparable to the case where a chemically synthesized sialidase inhibitor was used. These results demonstrated that RNA interference of sialidase can prevent the desialylation problem in glycoprotein production, resulting improved protein quality during the entire cell culture process. © 2006 Wiley Periodicals, Inc.
A Highly Tunable Family of Chiral Bisphospholanes for Rh‐Catalyzed Enantioselective Hydrogenation Reactions
Authors: Holz Jens , Zayas Odalys , Jiao Haijun , Baumann Wolfgang , Spannenberg Anke , Monsees Axel , Riermeier Thomas H. , Almena Juan , Kadyrov Renat , Börner Armin
Published: May 2006

A set of 16 new and closely related bisphospholane ligands have been prepared by using a highly flexible and convergent approach. Each synthesis can be performed on an industrially relevant scale. The bisphosphines differ in the nature of the bridge connecting both phospholane units. Bridges are formed by three‐, four‐, five‐ and six‐membered heterocyclic or alicyclic rings. Bisphospholanes and their Rh‐precatalysts have been investigated by using results of theoretical calculations (DFT) and analytic measurements (31P and 103Rh NMR spectroscopy, X‐ray structure analysis). The studies showed that catalysts based on ligands with maleic anhydride or maleimide bridges give constantly superior enantioselectivities in methanol as the solvent. This may account for optimised steric and electronic effects. However, by changing the solvent catalysts with other backbones can give rise to excellent results. This gives proof that simple correlations between steric and electronic properties and results in the enantioselective hydrogenation frequently claimed in literature are not general.
Reproducible and inducible knockdown of gene expression in mice
Authors: Yu Jing , McMahon Andrew P.
Published: May 2006

RNA interference (RNAi) has emerged as an efficient approach for rapid analysis of gene function. In mammalian cells, vector‐based expression of small hairpin RNAs (shRNA) produces potent and stable gene knockdown effects. An inducible RNAi system with reproducible levels of siRNA expression will extend the usefulness of this methodology to the identification of gene functions within the developing or adult mouse. We present evidence that an RNA polymerase III‐driven U6 promoter with stuffer sequences flanked by loxP sites inserted at three different sites within the promoter drives shRNA expression in a Cre recombinase‐dependent manner. We utilized this approach to develop a generic strategy for the reproducible knockdown of gene expression in mice. By placing the inducible shRNA cassette into the ROSA26 locus of the mouse, we were able to generate reproducible levels of controlled expression of shRNA to produce discernable phenotypes in vitro and in vivo. This approach circumvents the prescreening of random integration in embryonic stem cell clones and further enables conditional gene knockdown with temporal and/or tissue specificity. This methodology should expedite large‐scale functional studies. genesis 44:252–261, 2006. Published 2006 Wiley‐Liss, Inc.
More results on perfect (3,3,6k + 4; 6k − 2)‐threshold schemes
Authors: Ji L.
Published: May 2006

A (2,3)‐packing on X is a pair (X,$\cal A$), where $\cal A$ is a set of 3‐subsets (called blocks) of X, such that any pair of distinct points from X occurs together in at most one block. Its leave is a graph (X,E) such that E consists of all the pairs which do not appear in any block of $\cal A$. In this article, we shall construct a set of 6k − 2 disjoint (2,3)‐packings of order 6k + 4 with K1,3 ∪ 3kK2 or G1 ∪ (3k − 1)K2 as their common leave for any integer k ≥ 1 with a few possible exceptions (G1 is a special graph of order 6). Such a system can be used to construct perfect threshold schemes as noted by Schellenberg and Stinson (1989). © 2006 Wiley Periodicals, Inc. J Combin Designs
Direct determination of ciprofloxacin by mass spectrometry after a two‐step solid‐phase extraction using a molecularly imprinted polymer
Authors: Caro Ester , Marcé Rosa M. , Cormack Peter A. G. , Sherrington David C. , Borrull Francesc
Published: May 2006

A molecularly imprinted polymer (MIP) has been prepared for the first time with ciprofloxacin (CIPRO) as the template molecule, via a noncovalent synthetic procedure. Prior to its use as a sorbent in SPE, the MIP was evaluated chromatographically to confirm that it was indeed molecularly imprinted. The MIP was then used to extract CIPRO selectively from urine samples by means of a two‐step SPE procedure in which a commercial Oasis cartridge and a molecularly imprinted SPE cartridge were combined in series. This approach allowed the matrix compounds present in the samples to be removed effectively. The urine extracts obtained after this two‐step SPE procedure was applied were relatively clean compared to the original samples, and this made it possible to inject directly the extracts into a mass spectrometer and thus quantify CIPRO in urine samples at low levels and reduce the time of analysis.
A pilot study of perceived clinical usefulness of a new computer‐based tool for assessment of visual perception in occupational therapy practice
Authors: Reid Denise T. , Jutai Jeffrey
Published: May 2006

A new assessment instrument called the Componential Assessment of Visual Perception (CAVP)© has been developed recently by the authors. It was designed for use in occupational therapy practice, and in other practice areas such as neuropsychology, as a process‐based approach to the evaluation of visual perceptual functioning in children and adults with neurological disorders. In this paper, the CAVP is discussed in terms of its conceptual basis and relevance as an assessment of occupational functioning. In addition, the results of a preliminary study of the clinical usefulness of the CAVP are reported. In this study, a questionnaire designed to measure perceived clinical usefulness of the CAVP was completed by a group of experienced clinicians who routinely assess visual perceptual functioning in clients with neurological disorders. Clinicians were given a standardised demonstration of the CAVP program and a copy of the CAVP's documentation manual. The CAVP software program was installed on to each clinician's computer for a period of two weeks to allow them time to review and analyse it before completing the questionnaire. Overall, promising results regarding the CAVP's potential clinical usefulness were found. Results related to the CAVP's utility, ease of use, format, and appeal are presented, as well as a discussion of the study's limitations. In the final section of this paper, an example of selected CAVP client results is presented to demonstrate how to use it to isolate key processes that are significant in a client's perceptual performance. Copyright © 1997 Whurr Publishers Ltd.
Outer membrane vesicles of the VA‐MENGOC‐BC® vaccine against serogroup B of Neisseria meningitidis: Analysis of protein components by two‐dimensional gel electrophoresis and mass spectrometry
Authors: Uli Liliam , Castellanos‐Serra Lila , Betancourt Lazaro , Domínguez Francisco , Barberá Ramón , Sotolongo Franklin , Guillén Gerardo , Pajón Feyt Rolando
Published: May 2006

Neisseria meningitidis is a Gram‐negative bacterium responsible for significant mortality worldwide. While effective polysaccharides‐based vaccines exist against serogroups A, C, W135, and Y, no similar vaccine is suitable for children under 4 years against disease caused by serogroup B strains. Therefore, major vaccine efforts against this serogroup are based on outer membrane vesicles (OMVs), containing major outer membrane proteins. The OMV‐based vaccine produced by the Finlay Institute in Cuba (VA‐MENGOC‐BC®) contributed to the rapid decline of the epidemic in this Caribbean island. While the content of major proteins in this vaccine has been discussed, no detailed work of an outer membrane proteomic map of this, or any other, commercially available OMV‐derived product has been published so far. Since OMVs exhibit a large bias toward a few major proteins and usually contain a high content of lipids, establishing the adequate conditions for high resolution, 2‐DE of this kind of preparation was definitely a technical challenge. In this work, 2‐DE and MS have been used to generate a proteomic map of this product, detailing the presence of 31 different proteins, and it allows the identification of new putative protective protein components it contains.
Comparison of extraction procedures for proteome analysis of Streptococcus pneumoniae and a basic reference map
Authors: Encheva Vesela , Gharbia Saheer E. , Wait Robin , Begum Shajna , Shah Haroun N.
Published: May 2006

Streptococcus pneumoniae is an important human pathogen causing life‐threatening invasive diseases such as pneumonia, meningitis and bacteraemia. Despite major advances in our understanding of pneumococcal mechanisms of pathogenicity obtained through genomic studies very little has been achieved on the characterisation of the proteome of this pathogen. The highly complex structure of its cell envelope particularly amongst the various capsular forms enables the cell to resist lysis by conventional mechanical methods. It is therefore highly desirable to develop a cellular lysis and protein solubilisation procedure that minimises protein losses and allows for maximum possible coverage of the proteome of S. pneumoniae. Here we have utilised various combinations of mechanical or enzymatic cell lysis with two protein solubilisation mixtures urea/CHAPS‐based mixture or SDS/DTT‐based mixture in order to achieve best quality protein profiles using two proteomic technologies surface‐enhanced laser desorption ionisation (SELDI) TOF MS and 2‐DE. While urea/CHAPS‐based mixture combined with freeze/thawing provided enough material for good‐quality SELDI TOF MS fingerprints, a combination of mechanical, enzymatic and chemical lysis was needed to be used to successfully extract the desired protein content for 2‐DE analysis. The methods chosen were also assessed for reproducibility and tested on various capsular types of S. pneumoniae. As a result, good‐quality and reproducible profiles were created using various ProteinChip® arrays and more than 800 protein spots were separated on a single 2‐D gel of S. pneumoniae. Twenty‐five of the most abundant protein spots were identified using LC/MS/MS to create a reference map of S. pneumoniae. The proteins identified included glycolytic enzymes such as glyceraldehyde 3‐phosphate dehydrogenase, phosphoglycerate kinase, enolase etc. Several fermentation enzymes were also present including two of the components of the arginine deiminase system. Proteins involved in protein synthesis, such as translation factors and ribosomal proteins, as well as several chaperone proteins were also identified.
Exploring Allium species as a source of potential medicinal agents
Authors: Štajner D. , Milić N. , Čanadanović‐Brunet J. , Kapor A. , Štajner M. , Popović B. M.
Published: May 2006

It has been shown that Allium species may help to prevent tumor promotion, cardiovascular diseases and aging; all processes that are associated with free radicals. Therefore the Allium species of both cultivated species (Allium nutans L., Allium fistulosum L., Allium vineale L., Allium psekemense B. Fedtsch, Allium cepa L., Allium sativum L.) and wild species (Allium flavum L., Allium sphaerocephalum L., Allium atroviolaceum Boiss, Allium schenoprasum L., Allium vineale L., Allium ursinum L., Allium scorodoprasum L.) from various locations were investigated for their antioxidative properties. The leaves were examined for activities of antioxidative enzymes (catalase, peroxidase, superoxide‐dismutase, glutathione‐peroxidase), non‐enzymic antioxidants (reduced glutathione and total flavonoids), content of soluble proteins, vitamin C, carotenoids, chlorophylls a and b, as well as the quantities of malonyldialdehyde and ·OH and O2· – radicals. Using a contemporary spectroscopic fluorescent method, lipofuscin, ‘plant age pigments’ were determined. ESR spectroscopy was used to follow the decrease of oxygen radicals in the presence of extracts of Allium species in phosphate buffer (pH 7). The results showed that all Allium species had strong antioxidative properties due to their high concentration of total flavonoids, high content of carotenoids and chlorophylls, and very low concentrations of toxic oxygen radicals. ESR signals of DMPO‐OH radical adducts, in the presence of Allium extracts in phosphate buffer (pH 7), were reduced by up to 94.3%. Copyright © 2006 John Wiley & Sons, Ltd.
On the N2O correction used for mass spectrometric analysis of atmospheric CO2
Authors: Assonov S. S. , Brenninkmeijer C. A. M.
Published: May 2006

To obtain accurate values of δ13C(CO2) and δ18O(CO2) on environmental CO2 by mass spectrometry, the raw isotope data must be corrected for the isobaric N2O contribution. This is one of the analytical problems limiting inter‐laboratory δ13C(CO2) data consistency. The key parameter, the N2O relative ionisation efficiency (${\rm E}_{{\rm N}_2 {\rm O}}$), cannot be determined with sufficient accuracy by direct measurements of pure N2O. The determination of ${\rm E}_{{\rm N}_2 {\rm O}}$ by analyses on N2OCO2 mixtures of known isotope composition and mixing proportions has been recently suggested. In this work we propose a new method of N2O correction which uses the m/z 30 signal as a measure of the N2O/CO2 ratio, so that determinations of ${\rm E}_{{\rm N}_2 {\rm O}}$ and N2O content are not required. The method uses the fact that fragment‐ion spectra of N2O and CO2 are very specific. The formalism of the correction is considered. Various tests demonstrate that the new method is robust, stable and easy to implement in practice. The effective value $^{30} {\rm R}_{{\rm N}_2 {\rm O}}$ (the key parameter for the new correction) has to be calibrated on known N2OCO2 mixtures by measuring 30R signals only. The method accuracy we presently achieved is around 2.5% and any error which appears to come mostly from our N2OCO2 mixture preparation. Based on our tests and error considerations, the error of the proposed method that may be achieved is as low as ±1.5% (relative to the correction magnitude). For tropospheric CO2 this means ±0.003‰ and ±0.005‰ for δ13C(CO2) and δ18O(CO2), respectively. The proposed method may be valuable for small samples where no separate N2O determinations are available (e.g. ice core samples and CF‐IRMS measurements) as well as for determination of ${\rm E}_{{\rm N}_2 {\rm O}}$ and testing the ‘traditional’ N2O correction based on mass balance calculations. Copyright © 2006 John Wiley & Sons, Ltd.