Method development and optimization for the determination of selenium in bean and soil samples using hydride generation electrothermal atomic absorption spectrometry

The present investigation is the first part of an initiative to prepare a regional map of the natural abundance of selenium in various areas of Brazil, based on the analysis of bean and soil samples. Continuous-flow hydride generation electrothermal atomic absorption spectrometry (HG-ET AAS) with in situ trapping on an iridium-coated graphite tube has been chosen because of the high sensitivity and relative simplicity. The microwave-assisted acid digestion for bean and soil samples was tested for complete recovery of inorganic and organic selenium compounds (selenomethionine). The reduction of Se(VI) to Se(IV) was optimized in order to guarantee that there is no back-oxidation, which is of importance when digested samples are not analyzed immediately after the reduction step. The limits of detection and quantification of the method were 30 ng L(-1) Se and 101 ng L(-1) Se, respectively, corresponding to about 3 ng g(-1) and 10 ng g(-1), respectively, in the solid samples, considering a typical dilution factor of 100 for the digestion process. The results obtained for two certified food reference materials (CRM), soybean and rice, and for a soil and sediment CRM confirmed the validity of the investigated method. The selenium content found in a number of selected bean samples varied between 5.5 +/- 0.4 ng g(-1) and 1726 +/- 55 ng g(-1), and that in soil samples varied between 113 +/- 6.5 ng g(-1) and 1692 +/- 21 ng g(-1). (C) 2011 Elsevier B.V. All rights reserved.

The Development of Science Education Research in Brazil and Contributions from the History and Philosophy of Science

Over the last 50 years a new research area, science education research, has arisen and undergone singular development worldwide. In the specific case of Brazil, research in science education first appeared systematically 40 years ago, as a consequence of an overall renovation in the field of science education. This evolution was also related to the political events taking place in the country. We will use the theoretical work of Rene Kaes on the development of groups and institutions as a basis for our discussion of the most important aspects that have helped the area of science education research develop into an institution and kept it operating as such. The growth of this area of research can be divided into three phases: The first was related to its beginning and early configurations; the second consisted of a process of consolidation of this institution; and the third consists of more recent developments, characterised by a multiplicity of research lines and corresponding challenges to be faced. In particular, we will analyse the special contributions to this study gleaned from the field known as the history and philosophy of science.

Re-description and new combination of five New World species of Chrysotus Meigen, with comments on the Neotropical genus Lyroneurus Loew (Diptera: Dolichopodidae)

Five New World species of Chrysotus Meigen are redescribed, four of them herein transferred from Diaphorus Meigen: C. angustifrons (Robinson), comb.nov., C. maculatus (Parent), comb.nov. (= D. maculipennis Robinson), C. robustus(Robinson), comb. nov., C. spectabilis (Loew) and C. wirthi (Robinson), comb. nov. The female of C. maculatus is described for the first time. Terminalia of both males and females are illustrated. The previous suggestion that C. angustifrons, C. robustus, C. wirthi, and C. spectabilis and the Neotropical genus Lyroneurus Loew are closely related based on wing venation similarities is analyzed and rejected.

The Development of Dalton`s Atomic Theory as a Case Study in the History of Science: Reflections for Educators in Chemistry

The inclusion of the history of science in science curricula-and specially, in the curricula of science teachers-is a trend that has been followed in several countries. The reasons advanced for the study of the history of science are manifold. This paper presents a case study in the history of chemistry, on the early developments of John Dalton`s atomic theory. Based on the case study, several questions that are worth discussing in educational contexts are pointed out. It is argued that the kind of history of science that was made in the first decades of the twentieth century (encyclopaedic, continuist, essentially anachronistic) is not appropriate for the development of the competences that are expected from the students of sciences in the present. Science teaching for current days will benefit from the approach that may be termed the ""new historiography of science"".

Cross-National Analysis of the Associations between Traumatic Events and Suicidal Behavior: Findings from the WHO World Mental Health Surveys

Background: Community and clinical data have suggested there is an association between trauma exposure and suicidal behavior (i.e., suicide ideation, plans and attempts). However, few studies have assessed which traumas are uniquely predictive of: the first onset of suicidal behavior, the progression from suicide ideation to plans and attempts, or the persistence of each form of suicidal behavior over time. Moreover, few data are available on such associations in developing countries. The current study addresses each of these issues. Methodology/Principal Findings: Data on trauma exposure and subsequent first onset of suicidal behavior were collected via structured interviews conducted in the households of 102,245 (age 18+) respondents from 21 countries participating in the WHO World Mental Health Surveys. Bivariate and multivariate survival models tested the relationship between the type and number of traumatic events and subsequent suicidal behavior. A range of traumatic events are associated with suicidal behavior, with sexual and interpersonal violence consistently showing the strongest effects. There is a dose-response relationship between the number of traumatic events and suicide ideation/attempt; however, there is decay in the strength of the association with more events. Although a range of traumatic events are associated with the onset of suicide ideation, fewer events predict which people with suicide ideation progress to suicide plan and attempt, or the persistence of suicidal behavior over time. Associations generally are consistent across high-, middle-, and low-income countries. Conclusions/Significance: This study provides more detailed information than previously available on the relationship between traumatic events and suicidal behavior and indicates that this association is fairly consistent across developed and developing countries. These data reinforce the importance of psychological trauma as a major public health problem, and highlight the significance of screening for the presence and accumulation of traumatic exposures as a risk factor for suicide ideation and attempt.

Instability of Higher-Dimensional Charged Black Holes in the de Sitter World

We have shown that higher-dimensional Reissner-Nordstrom-de Sitter black holes are gravitationally unstable for large values of the electric charge and cosmological constant in D >= 7 space-time dimensions. We have found the shape of the slightly perturbed black hole at the threshold point of instability.

LOW-INTENSITY PULSED ULTRASOUND PRODUCED AN INCREASE OF OSTEOGENIC GENES EXPRESSION DURING THE PROCESS OF BONE HEALING IN RATS

The aim of this study was to measure the temporal expression of osteogenic genes during the process of bone healing in low-intensity pulsed ultrasound (LIPUS) treated bone defects by means of histopathologic and real-time polymerase chain reaction (PCR) analysis. Animals were randomly distributed into two groups (n = 30): control group (bone defect without treatment) and LIPUS treated (bone defect treated with LIPUS). On days 7, 13 and 25 postinjury, 10 rats per group were sacrificed. Rats were treated with a 30 mW/cm(2) LIPUS. The results pointed out intense new bone formation surrounded by highly vascularized connective tissue presenting a slight osteogenic activity, with primary bone deposition was observed in the group exposed to LIPUS in the intermediary (13 days) and late stages of repair (25 days) in the treated animals. In addition, quantitative real-time polymerase chain reaction (RT-qPCR) showed an upregulation of bone morphogenetic protein 4 (BMP4), osteocalcin and Runx2 genes 7 days after the surgery. In the intermediary period, there was no increase in the expression. The expression of alkaline phosphatase, BMP4 and Runx2 was significantly increased at the last period. Our results indicate that LIPUS therapy improves bone repair in rats and upregulated osteogenic genes, mainly at the late stages of recovery. (E-mail: a.renno@unifesp.br) (C) 2010 Published by Elsevier Inc. on behalf of World Federation for Ultrasound in Medicine & Biology.

Prevalence and Correlates of Bipolar Spectrum Disorder in the World Mental Health Survey Initiative

Context: There is limited information on the prevalence and correlates of bipolar spectrum disorder in international population-based studies using common methods. Objectives: To describe the prevalence, impact, patterns of comorbidity, and patterns of service utilization for bipolar spectrum disorder (BPS) in the World Health Organization World Mental Health Survey Initiative. Design, Setting, and Participants: Crosssectional, face-to-face, household surveys of 61 392 community adults in 11 countries in the Americas, Europe, and Asia assessed with the World Mental Health version of the World Health Organization Composite International Diagnostic Interview, version 3.0, a fully structured, lay-administered psychiatric diagnostic interview. Main Outcome Measures: Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) disorders, severity, and treatment. Results: The aggregate lifetime prevalences were 0.6% for bipolar type I disorder (BP-I), 0.4% for BP-II, 1.4% for subthreshold BP, and 2.4% for BPS. Twelve-month prevalences were 0.4% for BP-I, 0.3% for BP-II, 0.8% for subthreshold BP, and 1.5% for BPS. Severity of both manic and depressive symptoms as well as suicidal behavior increased monotonically from subthreshold BP to BP-I. By contrast, role impairment was similar across BP subtypes. Symptom severity was greater for depressive episodes than manic episodes, with approximately 74.0% of respondents with depression and 50.9% of respondents with mania reporting severe role impairment. Three-quarters of those with BPS met criteria for at least 1 other disorder, with anxiety disorders (particularly panic attacks) being the most common comorbid condition. Less than half of those with lifetime BPS received mental health treatment, particularly in low-income countries, where only 25.2% reported contact with the mental health system. Conclusions: Despite cross-site variation in the prevalence rates of BPS, the severity, impact, and patterns of comorbidity were remarkably similar internationally. The uniform increases in clinical correlates, suicidal behavior, and comorbidity across each diagnostic category provide evidence for the validity of the concept of BPS. Treatment needs for BPS are often unmet, particularly in low-income countries.

Twelve-Month Prevalence of and Risk Factors for Suicide Attempts in the World Health Organization World Mental Health Surveys

Objective: Although suicide is a leading cause of death worldwide, clinicians and researchers lack a data-driven method to assess the risk of suicide attempts. This study reports the results of an analysis of a large cross-national epidemiologic survey database that estimates the 12-month prevalence of suicidal behaviors, identifies risk factors for suicide attempts, and combines these factors to create a risk index for 12-month suicide attempts separately for developed and developing countries. Method: Data come from the World Health Organization (WHO) World Mental Health (WMH) Surveys (conducted 2001-2007), in which 108,705 adults from 21 countries were interviewed using the WHO Composite International Diagnostic Interview. The survey assessed suicidal behaviors and potential risk factors across multiple domains, including socio-demographic characteristics, parent psychopathology, childhood adversities, DSM-IV disorders, and history of suicidal behavior. Results: Twelve-month prevalence estimates of suicide ideation, plans, and attempts are 2.0%, 0.6%, and 0.3%, respectively, for developed countries and 2.1%, 0.7%, and 0.4%, respectively, for developing countries. Risk factors for suicidal behaviors in both developed and developing countries include female sex, younger age, lower education and income, unmarried status, unemployment, parent psychopathology, childhood adversities, and presence of diverse 12-month DSM-IV mental disorders. Combining risk factors from multiple domains produced risk indices that accurately predicted 12-month suicide attempts in both developed and developing countries (area under the receiver operating characteristic curve = 0.74-0.80). Conclusions: Suicidal behaviors occur at similar rates in both developed and developing countries. Risk indices assessing multiple domains can predict suicide attempts with fairly good accuracy and may be useful in aiding clinicians in the prediction of these behaviors. J Clin Psychiatry 2010;71(12):1617-1628 (C) Copyright 2010 Physicians Postgraduate Press, Inc.

Associations of serious mental illness with earnings: results from the WHO World Mental Health surveys

Background Burden-of-illness data, which are often used in setting healthcare policy-spending priorities, are unavailable for mental disorders in most countries. Aims To examine one central aspect of illness burden, the association of serious mental illness with earnings, in the World Health Organization (WHO) World Mental Health (WMH) Surveys. Method The WMH Surveys were carried out in 10 high-income and 9 low- and middle-income countries. The associations of personal earnings with serious mental illness were estimated. Results Respondents with serious mental illness earned on average a third less than median earnings, with no significant between-country differences (chi(2)(9)=5.5-8.1, P=0.5-0.79). These losses are equivalent to 0.3-0.8% of total national earnings. Reduced earnings among those with earnings and the increased probability of not earning are both important components of these associations: Conclusions These results add to a growing body of evidence that mental disorders have high societal costs. Decisions about healthcare resource allocation should take these costs into consideration.

Treatment of suicidal people around the world

Background Suicide is a leading cause of death worldwide; however, little information is available about the treatment of suicidal people, or about barriers to treatment. Aims To examine the receipt of mental health treatment and barriers to care among suicidal people around the world. Method Twenty-one nationally representative samples worldwide (n=55 302; age 18 years and over) from the World Health Organization`s World Mental Health Surveys were interviewed regarding past-year suicidal behaviour and past-year healthcare use. Suicidal respondents who had not used services in the past year were asked why they had not sought care. Results Two-fifths of the suicidal respondents had received treatment (from 17% in low-income countries to 56% in high-income countries), mostly from a general medical practitioner (22%), psychiatrist (15%) or non-psychiatrist (15%). Those who had actually attempted suicide were more likely to receive care. Low perceived need was the most important reason for not seeking help (58%), followed by attitudinal barriers such as the wish to handle the problem alone (40%) and structural barriers such as financial concerns (15%). Only 7% of respondents endorsed stigma as a reason for not seeking treatment. Conclusions Most people with suicide ideation, plans and attempts receive no treatment. This is a consistent and pervasive finding, especially in low-income countries. Improving the receipt of treatment worldwide will have to take into account culture-specific factors that may influence the process of help-seeking.

PULSATILITY INDEX CHANGE OF BRACHIAL ARTERY SHOWS BETTER REPRODUCIBILITY THAN FLOW-MEDIATED VASODILATION

We aim to evaluate intra- and interobserver reproducibility of brachial artery flow-mediated dilation (FMD) and of pulsatility index change (PI-C) 1 min after a 5-min forearm compression in pregnant women. Flow-mediated dilation and PI-C were assessed in 31 healthy pregnant women in 3 consecutive days, by two observers. A broader range of response to the stimulus was observed for PI-C (-58.99%-86.71%) than FMD (2.38%-27.01%). The intraclass correlation coefficients were higher for PI-C than for FMD (intra = 0.90 vs. 0.69, p = 0.047; inter = 0.94 vs. 0.61, p = 0.007). Therefore, PI-C measurements were more reliable than FMD. However, studies comprising of subjects with cardiovascular risk factors relating FMD and PI-C become necessary to validate this method for the study of endothelial dysfunction. (E-mail: wpmartins@gmail.com) (C) 2010 World Federation for Ultrasound in Medicine & Biology.

LOW-INTENSITY ULTRASOUND APPLICATION IN DISTAL RADIUS METAPHYSEAL BONE DEFECTS OF DOGS

We assessed the repair of transverse, 3-mm wide bone gaps created at the distal radius in 28 dogs that were randomly divided into two 14-animal groups; one was the control group and the other received a daily, 20-min application of low-intensity pulsed ultrasound for 100 days. Sequential radiographs, histomorphometrics, bone fluorescent histology and bone vascularity assessments found that all animals from both groups obtained a stage of hypertrophic-type nonunion with fibrocartilage tissue formation throughout the region of osteotomy. However, treated animals exhibited areas of endochondral ossification within the fibrocartilage region. There was no difference in type of vascularity or the newly formed bone process obtained by tetracycline labeling. Application of low-intensity ultrasound was not capable of significantly changing the reparative process and it may not be sufficiently powerful to overcome a combination of local deleterious effects on bone healing, created by gapping, excessive motion and periosteal resection. (E-mail: jbvolpon@fmrp.usp.br) (C) 2010 World Federation for Ultrasound in Medicine & Biology.