Genetic and environmental risk factors and their interactions for Parkinson's disease in a Chinese population

The interaction between genetic and environmental factors for PD was examined in a Chinese population. It was found that although the intron 2 MAOB (GT)(n) repeat polymorphism was not associated with PID in the population, a relationship might have been masked by the protective effect of tea drinking. In individuals who did not drink tea (<1 cup/day), the possession of short length less than or equal to 178 bp (GT), alleles conferred a borderline significant increased risk for PD (adjusted OR = 1.47; C.l. = 1.03-2. 1). As the extent of tea consumption increased, the association between the less than or equal to178 bp allele and PD disappeared. This result suggests that the MAOB gene may be associated with PD in Chinese if the putative protective effect of tea drinking is taken into account. The significance of this finding is unclear as the study may be limited because of its marginal significance and limited numbers. However, it does demonstrate the importance of considering putative positive and negative environmental risk factors in any examination of genetic risk factors for PD. (C) 2003 Elsevier Science Ltd. All rights reserved.

The influence of key chemical constituents in activated sludge on surface and flocculating properties

This paper examines the influence of the chemical constituents of activated sludge and extracted extracellular polymeric substances (EPS) on the surface properties, hydrophobicity, surface charge (SC) and flocculating ability (FA) of activated sludge floes. Activated sludge samples from 7 different full-scale wastewater treatment plants were examined. Protein and humic substances were found to be the dominant polymeric compounds in the activated sludges and the extracted EPS, and they significantly affected the FA and surface properties, hydrophobicity and SC, of the sludge floes. The polymeric compounds proteins, humic substances and carbohydrates in the sludge floes and the extracted EPS contributed to the negative SC, but correlated negatively to the hydrophobicity of sludge floes. The quantity of protein and carbohydrate within the sludge and the extracted EPS was correlated positively to the FA of the sludge floes, while increased amounts of humic substances resulted in lower FA. In contrast, increased amounts of total extracted EPS had a negative correlation to FA. The results reveal that the quality and quantity of the polymeric compounds within the sludge floes is more informative, with respect to understanding the mechanisms involved in flocculation, than if only the extracted EPS are considered. This is an important finding as it indicates that extracting EPS may be insufficient to characterise the EPS. This is due to the low extraction efficiency and difficulties involved in the separation of EPS from other organic compounds. Correlations were observed between the surface properties and FA of the sludge floes., This confirms that the surface properties of the, sludge flocs play an important role in the bioflocculation process but that also other interactions like polymer entanglement are important. (C) 2002 Elsevier Science Ltd. All rights reserved.

Public investment and the risk premium for equity

Analysis of the equity premium puzzle has focused on private-sector capital markets. However, the existence of an anomalous equity premium raises important issues in the evaluation of public-sector investment projects. These issues are explored below. We begin by formalizing the argument that an equity premium may arise from uninsurable systematic risk in labour income, and show that, other things being equal, increases in public ownership of equity will improve welfare, up to the point where the equity premium is eliminated. Finally, we consider policy implications and the optimal extent of public ownership.

Chemical characterisation of deep profile Ferrosols under sugarcane in wet tropical northern Queensland

The chemical properties of deep profile samples ( up to 12 m) of Ferrosols from northern Queensland were investigated to provide an understanding of the accumulation of nitrate ( NO3) within these soil profiles. The influence of other cations and anions present in the soil solution or on the exchange and the charge chemistry of the profiles were examined with respect to the NO3 accumulations. The major ions in the soil solution were Na, NO3, and chloride ( Cl). Distinct regions of anion accumulation were observed; SO4 accumulated in the upper profile of all cores, whereas NO3 and Cl accumulations were restricted to the lower profile of cores with appreciable AEC (> 1 cmol(c)/kg). Gaines-Thomas selectivity coefficients were used to indicate exchange preference for cations and anions, and are as follows: Al > Ca similar to Mg > K > Na and sulfate (SO4) > Cl similar to NO3. The selectivity of SO4 increased and the extractable SO4 decreased in the lower profile of all cores. This has important implications for the adsorption of NO3 and Cl. The NO3 and Cl accumulations were shown to correspond to a region of low SO4 occupancy of the exchange sites in the lower profile. Along with the high SO4 selectivity, this suggests that SO4 may control the positioning of the NO3 accumulations. It was concluded that the NO3 accumulations were relatively stable under current management practices, although the reduction in NO3 inputs would likely see the gradual replacement of NO3 with Cl as a result of their comparable selectivity for exchange sites.

Compositional changes of Australia-grown Western Schley pecans [Carya illinoinensis (Wangenh.) K. Koch] during maturation

Changes in composition during the maturation of Western Schley pecans [Carya illinoinensis (Wangenh.) K. Koch] grown in Australia were investigated. Pecans of different maturity levels were collected at monthly intervals between March and June in. 1999 and 2000 and analyzed for the concentrations of moisture, total lipid, sucrose, raffinose, protein, and the minerals aluminum, boron, calcium, copper, iron, potassium, magnesium, manganese, sodium, phosphorus, sulfur, and zinc. Moisture, total lipid, and calcium contents changed significantly (p < 0.05) with harvest time and maturity, whereas the other components did not. Western Schley pecans grown in Australia should be harvested after the shuck has opened and it is either green or brown in color to maximize total lipid content and quality. This occurred after May 11 in 1999 and after May 17 in 2000.

A technique to assess small-scale heterogeneity of chemical properties in soil aggregates

A new method is presented which allows the separation of the soil aggregate exterior from the aggregate core. The method employs a combination of aggregate freezing with rapid separation of aggregate exteriors using ultrasonic energy. The factors influencing the thickness of the removed aggregate surface layer include water content of the aggregate prior to freezing, temperature difference between that of the frozen aggregate and that of the liquid it is submerged in during sonification, sonification time and energy, and the type of the immersion liquid. The success of the method and the thickness of the removed aggregate surface were examined using barium ( Ba2+) as a tracer. Barium ( as BaCl2) is rapidly absorbed by soil and is present at only very low levels in natural soils. Surface layers of 0.2 - 0.4 cm thickness were successfully removed from aggregates of 1 - 4 cm diameter. Two examples are given from soils in northern NSW to demonstrate the occurrence of small- scale heterogeneity in soil chemical properties. Compared with the surface fraction, a 4 - 7% higher calcium concentration was found in the core fraction of a clay loam soil ( Dermosol). Conversely, on a cracking clay soil ( Vertosol), atrazine concentration was around 15 times greater in the aggregate surface fractions compared with core fractions. Compared with the traditional estimation of soil chemical properties on homogenised bulk soil samples, it is suggested that separate analysis of aggregate surface and core fractions could provide useful additional information on the relationships between soil properties and environmental responses.

Injury related risk behavior - a study of Australian skydivers

Risk taking behaviour has been identified as an important host-related determinant of injury in young adults. The aim of this study is to clarify the relationship between the two key elements of risk taking behaviour - ie, risk assessment and risk acceptance - in participants of a high risk sporting activity. Skydivers registered with the Australian Parachute Federation were sampled at several jump meetings held at three 'drop-zones' in North Eastern Australia. A cross sectional survey of 215 skydivers ascertained each subject's risk assessment of each of nine hypothetical sky diving scenes and whether or not they would jump in the described conditions. Variables which independently predicted an individual's risk assessment were age group (p < 0.05), gender (p < 0.05) and scene details (p < 0.001). Risk assessment was found to be a statistically significant predictor of the decision to jump, with a 22% decrease in the odds of jumping with every unit increase in risk assessment (OR = 0.78: 95% Cl; 0.76, 0.80). Gender was also found to be a statistically significant predictor of the decision to jump, with males being 19% more likely to jump than females, after controlling for age, experience, currency and risk assessment (OR = 1.19: 95% CI; 1.04, 1.38). The importance of these results is that, by quantifying the relationship between two key elements of risk taking behaviour and several important host factor determinants, they facilitate more informed discussion about the possible role of risk taking behaviour in the causation of injury.

Desenvolvimento de metodologia para determinação de Co, Cr, Fe, Mn, Ni, Se e V em amostras de água produzida da indústria do petróleo através da técnica ICP OES utilizando digestão por micro-ondas

O descarte ou reutilização da água produzida da indústria do petróleo é difícil por causa dos impactos ambientais causados devido à presença de alta salinidade e componentes tóxicos, ou pelo risco de obstrução nas colunas de produção devido à formação de incrustações que causam redução na produção de petróleo e enormes perdas no processo de extração. Assim, o conhecimento da composição química da água produzida é muito importante. O método proposto por este trabalho visa a determinação de elementos traço (Co, Cr, Fe, Mn, Ni, Se e V) em amostras de água produzida de petróleo por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) utilizando a digestão ácida assistida por micro-ondas para o preparo das amostras (15 g de amostra e 2 mL de HNO3 concentrado). A curva analítica construída em HNO3 2% v v-1 foi adotada para o método após verificar que não é necessário o uso de salinidade para equiparação de matriz. Para o elemento Ni, não há necessidade do uso de padrão interno, para os elementos Co, Cr, Fe, Mn e V os melhores resultados foram obtidos usando Sc como padrão interno. Para o elemento Se é recomendado o uso de Y como padrão interno. Os limites de detecção obtidos foram Co 0,67, Cr 1,2, Fe 2,3, Mn 0,49, Ni 1,9, Se 3,7 e V 5,5 μg L-1; e os limites de quantificação foram Co 2,2, Cr 4,0, Fe 7,7, Mn 1,6, Ni 6,5, Se 12,4 e V 18,3 μg L-1. A exatidão do procedimento foi verificada através de testes de recuperação em dois níveis de concentração (40 e 80 μg L-1) e análise dos materiais certificados de referência de água estuarina SLEW-2 e de água do mar NASS-5. Bons valores de recuperação foram obtidos e não houve diferença significativa (95% de confiança) entre os resultados obtidos e os valores certificados dos materiais de referência.

Qualidade da água da lagoa Juara (Serra/ES) : avaliações físicas, químicas e respostas fisiológicas e citogenéticas em plantas

A gestão dos recursos hídricos necessita da integração entre os critérios físicos e químicos, e os aspectos bióticos, os quais possibilitam identificar os efeitos combinados de substâncias e avaliar suas influências. Os sistemas testes Allium cepa e Tradescantia pallida, são utilizados para o estudo da poluição aquática a partir de aspectos citogenéticos. Além destes biomarcadores, os teores de clorofila também são utilizados em estudos de estresse devido ao reflexo a múltiplos fatores. Assim, o objetivo deste trabalho foi avaliar a qualidade da água da lagoa Juara (Município de Serra/ES) pela análise integrada de aspectos físicos, químicos e ecotoxicológicos a partir de estudos citogenéticos em A. cepa e T. pallida, e fotossintéticos nesta última espécie. Foram definidas três estações amostrais ao longo da lagoa e a partir de amostras de água foram analisados parâmetros tais como condutividade, oxigênio dissolvido, concentração de nutrientes e metais. A determinação dos metais ocorreu por análises de espectrometria de massa. O teste do A. cepa foi realizado a partir sementes germinadas em amostras de água da lagoa. Com plantas de T. pallida, foi realizado o ensaio da mitose em ponta de raiz de T. pallida e dosado os teores de pigmentos cloroplastídicos em folhas totalmente expandidas. Para tanto, foi realizado ensaio utilizando-se a água da lagoa como solvente para solução de Hoagland onde estacas previamente enraizadas de T. pallida foram expostas durante 24 horas e 40 dias para as avaliações citogenéticas e fotossintéticas, respectivamente. Foi realizado novo teste do A. cepa nas águas da lagoa após os 40 dias de ensaio para aferir a manutenção das propriedades químicas das amostras. A avaliação citogenética nas duas espécies envolveu a análise dos índice mitótico (IM), índice de aberrações cromossômicas (AC) e frequência de micronúcleos (MN). Para a análise estatística foi utilizada a análise de variância seguida pelo teste de Tukey (p < 0.05) para a comparação dos tratamentos durante a mesma campanha, e teste de Bonferroni (p < 0,05) para a comparação entre as campanhas. Os resultados físicos e químicos mensurados demonstram que a lagoa Juara apresenta indícios de eutroficação artificial. Duas estações amostrais, em pelo menos uma campanha amostral, apresentaram potenciais citotóxico, genotóxico e mutagênico. Todavia, esses potenciais não demonstram relação com os teores de Fe e Mn quantificados, levando a crer que tais pontos apresentam outros potenciais poluentes. Os danos citogenéticos observados apresentaram efeitos maximizados durante a segunda campanha, demostrando o efeito do período de chuva na intensificação da poluição nesse ambiente. O estudo do metabolismo fotossintético em T. pallida, demonstrou os teores de pigmentos cloroplastídicos relacionados ao elevado aporte de nutrientes presentes nas estações J2 e J3. Sendo o excesso destes, o provável responsável pelo teor inferior de pigmentos em J3. Observa-se que os ensaios com A. cepa e T. pallida responderam de maneira fidedigna ao risco potencial do ambiente, complementando as análises físicas e químicas usualmente utilizadas na avaliação da qualidade da água de ambientes lacustres.

Economic Analysis of Occupational Risk Prevention in the Construction Sector

The construction sector has one of the worst occupational safety and health records in Europe. The costs of this scenario are very high, namely costs for workers and their families, costs to organizations, resulting from the absence of workers due to illness, insurance premiums, costs resulting from reduced productivity, cost of replacement and training of workers, etc., and costs to society, which in turn increases the costs of health systems. This paper presents and discusses the development of a methodology for economic evaluation in the context of risk management, which will allow senior management to support decision making. The possible application of this methodology to the construction sector is discussed.

Availability of heavy metals in contaminated soil evidenced by chemical extractants

Heavy metals have been accumulating in Brazilian soils, due to natural processes, such as atmospheric deposition, or human industrial activities. For certain heavy metals, when in high concentrations in the soil, there is no specific extractant to determine the availability of these elements in the soil. The objective of the present study was to evaluate the availability of Cd, Cu, Fe, Mn, Pb and Zn for rice and soybeans, using different chemical extractants. In this study we used seven soil samples with different levels of contamination, in completely randomized experimental design with four replications. We determined the available concentrations of Cd, Cu, Fe, Mn, Pb and Zn extracted by Mehlich-1, HCl 0.1 mol L-1, DTPA, and organic acid extractants and the contents in rice and soybeans, which extracts were analyzed by ICP-OES. It was observed that Mehlich-1, HCl 0.1 mol L-1 and DTPA extractants were effective to assess the availability of Cd, Cu, Pb and Zn for rice and soybeans. However, the same was not observed for the organic acid extractant.

Chemical sterilization in in vitro propagation of Arundina bambusifolia Lindl. and Epidendrum ibaguense Kunth

There is a great demand for simpler and less costly laboratory techniques and for more accessible procedures for orchid breeders who do not have the necessary theoretical basis to use the traditional seed and clone production methods of orchids in vitro. The aim of this study was to assess the use of sodium hypochlorite (NaClO) as a decontaminant in the process of inoculating adult orchid explants of Arundina bambusifolia and Epidendrum ibaguenses. Solutions of NaClO (1.200, 2.400, 3.600, 4.800 and 6.000 mg L-1 - equivalent to 50, 100, 150, 200 and 250 mL L-1 of commercial bleach - CB) were sprayed on the explants (1.0 mL) and the culture medium (GB5), in the presence or absence of activated charcoal (2 g L-1). The explants used were nodal segments of field-grown adult plants. The procedures for inoculating the explants were conducted outside the laminar flow chamber (LFC), except for the control treatment (autoclaved medium and explant inoculation inside the LFC). The best results for fresh weight yield, height and number of shoots were obtained using NaClO in solution at 1.200 mg L-1 (equivalent to 50 mL L-1 commercial bleach) with activated charcoal in the culture medium. Fresh weight figures were 1.10 g/jar for Arundina bambusifolia and 0.16 g/jar for Epidendrum ibaguenses. Spraying the NaClO solutions controls the contamination of the culture medium already inoculated with the explants.