Caenorhabditis elegans mutants resistant to phosphine toxicity show increased longevity and cross-resistance to the synergistic action of oxygen

Phosphine (hydrogen phosphide, PH3) is the fumigant most widely used to protect stored products from pest infestation. Despite the importance of this chemical, little is known about its mode of action. We have created three phosphine-resistant lines (pre-1, pre-7, pre-33) in the model organism C. elegans, with LC50 values 2, 5, and 9 times greater than the fully susceptible parental strain. Molecular oxygen was shown to be an extremely effective synergist with phosphine as, under hyperoxic conditions, 100% mortality was observed in wild-type nematodes exposed to 0.1 mg/l phosphine, a nonlethal concentration in air. All three mutants were resistant to the synergistic effects of oxygen in proportion to their resistance to phosphine with one mutant, pre-33, showing complete resistance to this synergism. We take the proportionality of cross-resistance between phosphine and the synergistic effect of oxygen to imply that all three mutants circumvent a mechanism of phosphine toxicity that is directly coupled to oxygen metabolism. Compared with the wild-type strain, all three mutants have an extended average life expectancy of from 12.5 to 25.3%. This is consistent with the proposed involvement of oxidative stress in both phosphine toxicity and ageing. Because the wild-type and mutant nematodes develop at the same rate, the longevity is unlikely to be caused by a clk-type reduction in oxidative metabolism, a potential alternative mechanism of phosphine resistance.

Characterisation of grafted supports used for solid-phase synthesis

A series of 'pellicular' type supports were fabricated by direct gamma-radiation-mediated graft polymerisation of styrene onto polypropylene, followed by aminomethylation. Raman spectroscopy was used for measuring the level of penetration of polystyrene graft into polypropylene, and other structural features such as density of graft and depth of functionalisation. The kinetics of the coupling of fluorenylmethylcarbamate (Fmoc)-labelled amino acids, to the aminomethylated polystyrene grafts have been measured by UV absorption followed cleavage of the Fmoc chromophore. The Raman spectroscopy results showed that for this series of experiments the calculated rate coefficient for coupling of Fmoc-labelled amino acids was primarily dependent on graft thickness, but was also influenced by the proportion of polystyrene graft to polypropylene. In general, it was also shown that with increasing loading capacity of support the calculated rate coefficient for amino-acid coupling decreased correspondingly. In addition, a support that had both a high rate coefficient and a high loading capacity was prepared from polypropylene base material with a co-continuous porous structure (high surface area). (C) 2003 Society of Chemical Industry.

Applied physiology and game analysis of rugby union

Increased professionalism in rugby has elicited rapid changes in the fitness profile of elite players. Recent research, focusing on the physiological and anthropometrical characteristics of rugby players, and the demands of competition are reviewed. The paucity of research on contemporary elite rugby players is highlighted, along with the need for standardised testing protocols. Recent data reinforce the pronounced differences in the anthropometric and physical characteristics of the forwards and backs. Forwards are typically heavier, taller, and have a greater proportion of body fat than backs. These characteristics are changing, with forwards developing greater total mass and higher muscularity. The forwards demonstrate superior absolute aerobic and anaerobic power, and Muscular strength. Results favour the backs when body mass is taken into account. The scaling of results to body mass can be problematic and future investigations should present results using power function ratios. Recommended tests for elite players include body mass and skinfolds, vertical jump, speed, and the multi-stage shuttle run. Repeat sprint testing is a possible avenue for more specific evaluation of players. During competition, high-intensity efforts are often followed by periods of incomplete recovery. The total work over the duration of a game is lower in the backs compared with the forwards; forwards spend greater time in physical contact with the opposition while the backs spend more time in free running, allowing them to cover greater distances. The intense efforts undertaken by rugby players place considerable stress on anaerobic energy sources, while the aerobic system provides energy during repeated efforts and for recovery. Training should focus on repeated brief high-intensity efforts with short rest intervals to condition players to the demands of the game. Training for the forwards should emphasise the higher work rates of the game, while extended rest periods can be provided to the backs. Players should not only be prepared for the demands of competition, but also the stress of travel and extreme environmental conditions. The greater professionalism of rugby union has increased scientific research in the sport; however, there is scope for significant refinement of investigations on the physiological demands of the game, and sports-specific testing procedures.

Quality of life assessment in the community-dwelling elderly: Validation of the Assessment of Quality of Life (AQoL) Instrument and comparison with the SF-36

Measurement of Health-Related Quality of Life (HRQoL) of the elderly requires instruments with demonstrated sensitivity, reliability, and validity, particularly with the increasing proportion of older people entering the health care system. This article reports the psychometric properties of the 12-item Assessment of Quality of Life (AQoL) instrument in chronically ill community-dwelling elderly people with an 18-month follow-up. Comparator instruments included the SF-36 and the OARS. Construct validity of the AQoL was strong when examined via factor analysis and convergent and divergent validity against other scales. Receiver Operator Characteristic (ROC) curve analyses and relative efficiency estimates indicated the AQoL is sensitive, responsive, and had the strongest predicative validity for nursing home entry. It was also sensitive to economic prediction over the follow-up. Given these robust psychometric properties and the brevity of the scale, AQoL appears to be a suitable instrument for epidemiologic studies where HRQoL and utility data are required from elderly populations. (C) 2003 Elsevier Science Inc. All rights reserved.

Selective entrainment of sediment graded by size and density under waves

The influence of near-bed sorting processes on heavy mineral content in suspension is discussed. Sediment concentrations above a rippled bed of mixed quartz and heavy mineral sand were measured under regular nonbreaking waves in the laboratory. Using the traditional gradient diffusion process, settling velocity would be expected to strongly affect sediment distribution. This was not observed during present trials. In fact, the vertical gradients of time-averaged suspension concentrations were found to be similar for the light and heavy minerals, despite their different settling velocities. This behavior implies a convective rather than diffusive distribution mechanism. Between the nonmoving bed and the lowest suspension sampling point, fight and heavy mineral concentration differs by two orders of magnitude. This discrimination against the heavy minerals in the pickup process is due largely to selective entrainment at the ripple face. Bed-form dynamics and the nature of quartz suspension profiles are found to be little affected by the trialed proportion of overall heavy minerals in the bed (3.8-22.1%).

Avalia????o de impacto do Programa de Fortalecimento e Melhoria da Qualidade dos Hospitais do SUS/ Minas Gerais (Pro-Hosp)

Este estudo avaliou o impacto do Programa de Fortalecimento e Melhoria da Qualidade dos Hospitais do SUS-MG (Pro-Hosp). Para tanto, foi empregado o m??todo diferen??as-em-diferen??as, que permite avaliar o impacto de pol??ticas p??blicas quando o indicador avaliado ?? observado em mais de um per??odo no tempo. Foram selecionados quatro indicadores de desempenho hospitalar: a propor????o m??dia de ces??rea, a taxa m??dia de ocupa????o, a taxa m??dia de mortalidade e o tempo m??dio de perman??ncia. Constatou-se que o Pro-Hosp teve impacto na propor????o m??dia de ces??reas no sentido esperado, ou seja, de reduzi-las

Estudo do processo de secagem em leito de espuma de cenoura, tomate, beterraba e morango

Em geral, produtos agrícolas são produzidos em larga escala e essa produtividade cresce proporcionalmente ao seu consumo. Entretanto, outro fator também cresce de forma proporcional, as perdas pós-colheita, o que sugere a utilização de tecnologias para aumentar a utilização desses produtos mitigando o desperdício e aumentando sua a vida de prateleira. Além disso, oferecer o produto durante o período de entressafra. No presente trabalho, foi utilizado à tecnologia de secagem em leito de espuma aplicada a cenoura, beterraba, tomate e morango, produtos amplamente produzidos e consumidos no Brasil. Neste trabalho, os quatros produtos foram submetidos à secagem em leito de espuma em secador com ar circulado em temperaturas controladas de 40, 50, 60, 70 e 80 °C. A descrição da cinética de secagem foi realizada pelo ajuste de modelos matemáticos para cada temperatura do ar de secagem. Além disso, foi proposto um modelo matemático generalizado ajustado por regressão não linear. O modelo de Page obteve o melhor ajuste sobre os dados de secagem em todos os produtos testados, com um coeficiente de determinação (R²) superior a 98% em todas as temperaturas avaliadas. Além disso, foi possível modelar a influência da temperatura do ar sobre o parâmetro k do modelo de Page através da utilização de um modelo exponencial. O coeficiente de difusão efetiva aumentou com a elevação da temperatura, apresentando valores entre 10-8e 10-7 m².s-¹ para as temperaturas de processo. A relação entre o coeficiente de difusão efetiva e a temperatura de secagem pôde ser descrita pela equação de Arrhenius.

Desenvolvimento e padronização de um método para determinação da sensibilidade do mycobacterium tuberculosis a fármacos contra tuberculose

A resistência a fármacos antituberculose tem constituído uma grande ameaça ao controle da tuberculose em âmbito mundial. A sua detecção precoce permite ao médico instituir um esquema de tratamento mais adequado ao paciente e consequentemente quebrar a cadeia de transmissão dos bacilos. Os testes de sensibilidade a antimicrobianos atuais, embora eficientes, são caros e/ou demorados e/ou trabalhosos. Com base nesta premissa, nos propusemos a desenvolver e padronizar um método fenotípico direto para determinação da sensibilidade do Mycobacterium tuberculosis a antimicrobianos de primeira linha do tratamento da tuberculose. Para o desenvolvimento deste novo teste, utilizaram-se os princípios do método das proporções e do exame de cultura pelo método de Ogawa–Kudoh. O estudo foi dividido em duas fases. A primeira, caracterizada pelo desenvolvimento e padronização do método proposto e a segunda, pela análise da concordância entre o método desenvolvido e o método do MGIT (padrão-ouro). Na primeira fase, foram realizados diversos ensaios para definir: os volumes de absorção e de liberação de líquidos de diferentes tipos de swab, o meio de cultura, as concentrações dos antimicrobianos e o tempo de leitura/interpretação das culturas. Além disso, foi verificado se a amostra deveria ou não ser diluída. Com base nos resultados destes ensaios, padronizou-se o método com: swab comercial, em meio de cultura Ogawa- Kudoh contendo separadamente 0,2 μg/mL de isoniazida, 40,0 μg/mL de rifampicina, 10,0 μg/mL de estreptomicina e 500,0 μg/mL de ácido para-nitrobenzóico. Padronizou-se ainda a inoculação da amostra de escarro de forma direta, ou seja, sem diluir e a leitura/interpretação do resultado do teste no período entre 21 e 28 dias. A análise comparativa entre este método e o teste de sensibilidade a antimicrobianos no sistema MGIT realizada na segunda fase do projeto indicou um índice kappa igual a 1,000, ou seja, uma concordância muito boa em relação ao padrão-ouro. Diante desses resultados promissores, acreditamos que o método desenvolvido apresente um grande potencial para ser utilizado em laboratórios com pouca infra-estrutura, por ser de baixo custo, fácil execução e relativamente rápido.

Efeitos do comitê de auditoria e do conselho fiscal na qualidade da informação contábil no Brasil

Esta dissertação foi desenvolvida com o objetivo de investigar os efeitos da instalação e das características do Conselho Fiscal e do Comitê de Auditoria sobre a qualidade das informações contábeis no Brasil. As características estudadas foram à independência e a qualificação dos membros. As proxies da qualidade da informação contábil foram relevância, tempestividade e conservadorismo condicional. A amostra utilizada foi composta por empresas brasileiras, listadas na Bolsa de Valores, Mercadorias e Futuros de São Paulo (BM&FBovespa), com liquidez anual superior a 0,001, no período de 2010 a 2013. Os dados foram coletados na base de dados Comdinheiro e nos Formulários de Referência das empresas, disponíveis no sítio eletrônico da Comissão de Valores Mobiliários (CVM) ou BM&FBovespa. Os modelos de qualidade da informação foram adaptados ao recorte metodológico e estimados pelo método dos mínimos quadrados ordinários (MQO), com erros-padrão robustos clusterizados por firma. Os resultados revelaram efeitos da instalação dos órgãos analisados sobre as proxies de qualidade da informação contábil. A instalação do Conselho Fiscal impactou positivamente a relevância do patrimônio líquido, enquanto a instalação do Comitê de Auditoria, a relevância do lucro. Esses resultados podem indicar diferenças no direcionamento da atenção desses órgãos: em proteger o patrimônio da entidade para os acionistas (Conselho Fiscal) ou em assegurar números mais confiáveis sobre o desempenho dos administradores (Comitê de Auditoria). Paralelamente, os resultados para a instalação do Conselho Fiscal de forma permanente inferiu força desse órgão como mecanismo de controle, ao invés da instalação somente a pedido dos acionistas. Já, a implementação do Conselho Fiscal Turbinado se mostrou ineficiente no controle da qualidade das informações contábeis. Na análise das características, a independência dos membros do Comitê de Auditoria impactou a relevância do lucro. Ao passo que a independência do Conselho Fiscal impactou a relevância do patrimônio líquido e o conservadorismo condicional (reconhecimento oportuno de perdas econômicas). Essas associações foram mais significantes quando os membros do Conselho Fiscal eram independentes dos acionistas controladores. Na análise da qualificação dos membros, foram encontradas evidências positivas na relação entre a relevância do patrimônio líquido e a maior proporção de membros do Conselho Fiscal com qualificação em Business (Contabilidade, Administração e Economia). O conservadorismo condicional foi maior na medida em que a qualificação dos membros do Conselho Fiscal convergia para a Contabilidade. Os resultados da qualificação dos membros do Comitê de Auditoria demonstraram relevância do lucro na presença de, ao menos, um Contador e na maior proporção de membros com qualificação tanto em Contabilidade como em Business; sendo mais significante conforme a qualificação dos membros do Comitê de Auditoria convergia para a Contabilidade.

Gender, wages, and productivity: an analysis of the tourism industry in northern Portugal

Tourism represents a major economic activity in Portugal, with an enormous wealth and employment growth potential. A significant proportion of jobs in the industry tourism are occupied by women, given that this industry is characterized by a relatively higher percentage of female employees. Despite the evidence of female progress with regard to their role in the Portuguese labor market, women continue to earn less than their male counterparts. This is clearly the case of the tourism industry, where statistics reveal a persistent gender wage gap. The objective of this paper is to provide empirical evidence on the determinants of gender wage inequality in the tourism industry in northern Portugal. Relying on firm-level wage equations and production functions, gender wage and productivity differentials are estimated and then compared. The comparison of these differentials allows inferring whether observed wage disparities are attributable to relatively lower female productivity, or instead disparities are due to gender wage discrimination. This approach is applied to tourism industry data gathered in the matched employer-employee data set Quadros de Pessoal (Employee Records). The main findings indicate that female employees in the tourism industry in northern Portugal are less productive than their male colleagues and that gender differences in wages are fully explained by gender differences in productivity.

Hydraulic conductivity in response to exchangeable sodium percentage and solution salt concentration

Hydraulic conductivity is determined in laboratory assays to estimate the flow of water in saturated soils. However, the results of this analysis, when using distilled or deionized water, may not correspond to field conditions in soils with high concentrations of soluble salts. This study therefore set out to determine the hydraulic conductivity in laboratory conditions using solutions of different electrical conductivities in six soils representative of the State of Pernambuco, with the exchangeable sodium percentage adjusted in the range of 5-30%. The results showed an increase in hydraulic conductivity with both decreasing exchangeable sodium percentage and increasing electrical conductivity in the solution. The response to the treatments was more pronounced in soils with higher proportion of more active clays. Determination of hydraulic conductivity in laboratory is routinely performed with deionized or distilled water. However, in salt affected soils, these determinations should be carried out using solutions of electrical conductivity different from 0 dS m-1, with values close to those determined in the saturation extracts.

Application of GA3 and girdling of branches on the production of extemporaneous fruits of 'Tahiti' acid lime

The objective of this study was to evaluate the effect of girdling of branches and the application of GA3, still in the main crop flowering on the formation of reproductive structures, the fruit set of the following extemporaneous flowering of 'Tahiti' acid lime. This work used a randomized block design with five replications in a 4x3 factorial design. The first factor was the foliar application of GA3, 88 days before extemporaneous flowering at five concentrations (0, 7, 14 and 21 mg.L-1). The second factor was the girdling times, 108 days before flowering onset (A108AF), 78 days before flowering (A78AF) plus no-girdling control (NG). In extemporaneous flowering, the proportion of buds, flowers and fruits that abscised was 38.75, 31.25 and 18.64% respectively and 11.34% of all reproductive structures formed were collected. GA3 did not affect fruit set. Girdling increased fruit set by 229 and 256% at A108DAF and A78DAF respectively, in relation to NG plants. The GA3 reduced the formation of floral structures, which resulted in a quadratic increase in field production by reducing the competition for photoassimilates among fruits. The concentration of 21 mg.L-1 was the most productive, with 15.97 fruit.plant-1.