Study of metals transfer from environment using teeth as biomonitor

We investigated chronic incorporation of metals in individuals from poor families, living in a small, restrict and allegedly contaminated area in Sao Paulo city, the surroundings of the Guarapiranga dam, responsible for water supply to 25% of the city population. A total of 59 teeth from individuals 7 to 60 years old were collected. The average concentrations of Pb, Cd, Fe, Zn, Mn, Ni and Cr were determined with an Atomic Absorption Spectrophotometer. The concentrations of all metals as function of the individuals` age exhibited a remarkable similarity: peaks between 7 and 10 years and sharply decreasing at higher ages, which could be attributed to alimentary habits and persistence to metals exposure all along the individuals` life span. From all the measured metals, lead and cadmium were a matter of much more concern since their measured values are close to the upper limits of the world wide averages. (C) 2009 Elsevier Ltd. All rights reserved.

Insights into the dynamics and sources of atmospheric lead and particulate matter in Sao Paulo, Brazil, from high temporal resolution sampling

We present the first results of a study investigating the processes that control concentrations and sources of Pb and particulate matter in the atmosphere of Sao Paulo City Brazil Aerosols were collected with high temporal resolution (3 hours) during a four-day period in July 2005 The highest Pb concentrations measured coincided with large fireworks during celebration events and associated to high traffic occurrence Our high-resolution data highlights the impact that a singular transient event can have on air quality even in a megacity Under meteorological conditions non-conducive to pollutant dispersion Pb and particulate matter concentrations accumulated during the night leading to the highest concentrations in aerosols collected early in the morning of the following day The stable isotopes of Pb suggest that emissions from traffic remain an Important source of Pb in Sao Paulo City due to the large traffic fleet despite low Pb concentrations in fuels (C) 2010 Elsevier BV All rights reserved

Use of Metals and Anion Species with Chemometrics Tools for Classification of Unprocessed and Processed Coconut Waters

Coconut water is a natural isotonic, nutritive, and low-caloric drink. Preservation process is necessary to increase its shelf life outside the fruit and to improve commercialization. However, the influence of the conservation processes, antioxidant addition, maturation time, and soil where coconut is cultivated on the chemical composition of coconut water has had few arguments and studies. For these reasons, an evaluation of coconut waters (unprocessed and processed) was carried out using Ca, Cu, Fe, K, Mg, Mn, Na, Zn, chloride, sulfate, phosphate, malate, and ascorbate concentrations and chemometric tools. The quantitative determinations were performed by electrothermal atomic absorption spectrometry, inductively coupled plasma optical emission spectrometry, and capillary electrophoresis. The results showed that Ca, K, and Zn concentrations did not present significant alterations between the samples. The ranges of Cu, Fe, Mg, Mn, PO (4) (3-) , and SO (4) (2-) concentrations were as follows: Cu (3.1-120 A mu g L(-1)), Fe (60-330 A mu g L(-1)), Mg (48-123 mg L(-1)), Mn (0.4-4.0 mg L(-1)), PO (4) (3-) (55-212 mg L(-1)), and SO (4) (2-) (19-136 mg L(-1)). The principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied to differentiate unprocessed and processed samples. Multivariated analysis (PCA and HCA) were compared through one-way analysis of variance with Tukey-Kramer multiple comparisons test, and p values less than 0.05 were considered to be significant.

The sources of stress experienced by professional Australian footballers

Previous studies looking at the sources of stress in sport have generally overlooked the unique experiences of professional athletes participating in team sports. This paper describes the results of a qualitative study aimed at identifying the sources of stress experienced by a cross-section of professional Australian footballers. Players from two Australian Football League clubs took part in the study involving in-depth, one-to-one interviews and focus group discussions. The results revealed that players identified sources of stress that went beyond those associated with the competitive event (such as poor performances) and included a lack of feedback, difficulty balancing football and study commitments, and job insecurity. The influence of both competition and non-competition sources of stress parallels previous research involving non-professional athletes and indicates that the entire sporting experience needs to be taken into account when developing stress management strategies.

Two sources of Michael Polanyi`s prototypal notion of incommensurability: Evans-Pritchard on Azande witchcraft and St Augustine on conversion

Michael Polanyi argues in Personal Knowledge (1958) that conceptual frameworks involved in major scientific controversies are separated by a `logical gap'. Such frameworks, according to Polanyi (1958: 151), are logically disconnected: their protagonists think differently, use different languages and occupy different worlds. Relinquishing one framework and adopting another, Polanyi's scientist undergoes a `conversion' to a new `faith'. Polanyi, in other words, presaged Kuhn and Feyerabend's concept of incommensurability. To what influences was Polanyi subject as he developed his concept of the logical gap? The answer, as unfolded in this article, is twofold: Evans-Pritchard's Witchcraft, Oracles and Magic among the Azande and the Confessions of St Augustine.

Using inorganic polymer to reduce leach rates of metals from brown coal fly ash

The burning of brown coal for electricity generation produces thousands of tonnes of fly ash each year. Treatment of the fly ash can reduce leach rates of metals and allow it to be disposed in less prescribed landfill. A geopolymer matrix was investigated as a potential stabilisation method for fly ash obtained from electrostatic precipitators and ash disposal ponds. The ratio of fly ash and geopolymer was varied to determine the effects of different compositions on leaching rates. The major element leachate concentrations obtained from pond ash were lower than that of precipitator fly ash. Conversely, precipitator ash-geopolymers were better for trace heavy metal stabilisation. Effective reduction of elemental concentrations in the leachate has been achieved, particularly for calcium, arsenic, selenium, strontium and barium. Scanning electron microscopy revealed the distribution of metals originated from fly ash and from added geopolymer material. It also showed that some elements are leached from ash particles to the geopolymer phase and others remained as undissolved particles. Qualitative analysis showed that fly ash particles interacted with the geopolymers phase through surface reactions.

Sources of doubt, sources of duty: HLA Hart on international law

In many ways HLA Hart’s critical analysis of the concept of law, with its repudiation of simple command theories of legal obligation, is at the same time a critique of the notion of state sovereignty. It is therefore an adumbration, if no more, of a radical reconceptualisation of international law, one which redefines the distinction between municipal and in-ternational jurisdiction. This paper is an exploration of what Hart could or ‘should’ have said about international law, based as much as possible on what he did say about international law and law in general. After some introductory comments it outlines Hart’s general analysis of law, with particular reference to the relevance for our understanding of international law.

B2B electronic markets: a conceptual model for analyzing the sources of business value

This paper describes research supporting the development of a conceptual model for understanding the sources of business value of Business-to-Business (B2B) Electronic Markets. Based on six case studies and an analysis of current literature, Aggregation, Matching, and Integration emerged as the three key sources of business value. The framework provides a structured and systematic approach for understanding various B2B Electronic Market models, and helps develop strategies to leverage these sources of business value.

Sources of productivity growth in Australian textile and clothing firms

This paper estimates the sources of productivity growth in Australian textile and clothing firms based on the Business Longitudinal Survey (BLS) from 1995 to 1998. Productivity growth estimates have been obtained for each sub-category of textile and clothing firms. Sources of growth in multifactor productivity (MFP) are examined with growth in technical efficiency and scale effects based on estimates of stochastic frontier production functions. Separate estimates of output growth have been compared with the productivity growth estimates for each of the product categories. MFP improved in all clothing firms and declined in textile firms over 1997–1998 by four-digit level of Australia New Zealand Standard Industrial classification Scheme (ANZSIC). MFP declined in most major categories of both textile and clothing firms in 1995–1997. Changes in technical efficiency mostly dominated scale effects in the overall direction of MFPG in both textile and clothing firms. The findings of the study provide evidence for policies for improving the firms' operative performance in the ongoing liberalised regime.

Sources of productivity growth in Australian textile and clothing firms

This paper estimates the sources of productivity growth in Australian textile and clothing firms based on the Business Longitudinal Survey (BLS) from 1995 to 1998. Productivity growth estimates have been obtained for each sub-category of textile and clothing firms. Sources of growth in multifactor productivity (MFP) are examined with growth in technical efficiency and scale effects based on estimates of stochastic frontier production functions. Separate estimates of output growth have been compared with the productivity growth estimates for each of the product categories. MFP improved in all clothing firms and declined in textile firms over 1997–1998 by four-digit level of Australia New Zealand Standard Industrial classification Scheme (ANZSIC). MFP declined in most major categories of both textile and clothing firms in 1995–1997. Changes in technical efficiency mostly dominated scale effects in the overall direction of MFPG in both textile and clothing firms. The findings of the study provide evidence for policies for improving the firms' operative performance in the ongoing liberalised regime.

Sources of well-being and commitment of staff in the Australian Disability Employment Services

This study examined the role of working conditions in predicting the psychological health, job satisfaction and organisational commitment of personnel responsible for helping people with disabilities gain employment in the mainstream Australian labour market. The working conditions were assessed using two theories: the Job Strain Model (job demand, social support and job control) and Psychological Contract Theory (unwritten reciprocal obligations between employers and employees). In the case of the Job Strain Model, the generic dimensions had been augmented by industry-specific sources of stress. A cross-sectional survey was undertaken in June and July 2005 with 514 staff returning completed questionnaires (representing a response rate of 30%). Comparisons between respondents and non-respondents revealed that on the basis of age, gender and tenure, the sample was broadly representative of employees working in the Australian disability employment sector at that time. The results of regression analyses indicate that social support was predictive of all of the outcome measures. Job control and the honouring of psychological contracts were both predictive of job satisfaction and commitment, while the more situation-specific stressors - treatment and workload stressors - were inversely related to psychological health (i.e. as concern regarding the treatment and workload stressors increased, psychological health decreased). Collectively, these findings suggest that strategies aimed at combating the negative effects of large-scale organisational change could be enhanced by addressing several variables represented in the models - particularly social support, job control, psychological contracts and sector-specific stressors.

Describing individual incidents of sexual abuse: a review of research on the effects of multiple sources of information on children's reports

Objective: For successful prosecution of child sexual abuse, children are often required to provide reports about individual, alleged incidents. Although verbally or mentally rehearsing memory of an incident can strengthen memories, children’s report of individual incidents can also be contaminated when they experience other events related to the individual incidents (e.g., informal interviews, dreams of the incident) and/or when they have similar, repeated experiences of an incident, as in cases of multiple abuse.

Method: Research is reviewed on the positive and negative effects of these related experiences on the length, accuracy, and structure of children’s reports of a particular incident.

Results: Children’s memories of a particular incident can be strengthened when exposed to information that does not contradict what they have experienced, thus promoting accurate recall and resistance to false, suggestive influences. When the encountered information differs from children’s experiences of the target incident, however, children can become confused between their experiences—they may remember the content but not the source of their experiences.

Conclusions: We discuss the implications of this research for interviewing children in sexual abuse investigations and provide a set of research-based recommendations for investigative interviewers.