113,555 research outputs found

    Combined impact of healthy lifestyle factors on risk of asthma, rhinoconjunctivitis and eczema in school children: ISAAC phase III

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    Background Asthma is not the key focus of prevention strategies. A Healthy Lifestyle Index (HLI) was developed to examine the combined effect of modifiable lifestyle factors on asthma, rhinoconjunctivitis and eczema using data from the International Study of Asthma and Allergies in Childhood (ISAAC) phase III. Methods Information on symptoms of asthma, rhinoconjunctivitis, eczema and several lifestyle factors was obtained from children aged 6–7 years through written questionnaires. The HLI combined five lifestyle factors: no parental smoking, child’s adherence to Mediterranean diet, child’s healthy body mass index, high physical activity and non-sedentary behaviour. The association between the HLI and risk of asthma, rhinoconjunctivitis and eczema was evaluated using multilevel mixed-effects logistic regression models. Findings Data of 70 795 children from 37 centres in 19 countries were analysed. Each additional healthy lifestyle factor was associated with a reduced risk of current wheeze (OR 0.87, 95% CI 0.84 to 0.89), asthma ever (OR 0.89, 95% CI 0.87 to 0.92), current symptoms of rhinoconjunctivitis (OR 0.95, 95% CI 0.92 to 0.97) and current symptoms of eczema (OR 0.92, 95% CI 0.92 to 0.98). Theoretically, if associations were causal, a combination of four or five healthy lifestyle factors would result into a reduction up to 16% of asthma cases (ranging from 2.7% to 26.3 % according to region of the world). Conclusions These findings should be interpreted with caution given the limitations to infer causality from cross-sectional observational data. Efficacy of interventions to improve multiple modifiable lifestyle factors to reduce the burden asthma and allergy in childhood should be assessed

    Systematic review of worldwide variations of the prevalence of wheezing symptoms in children

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    Background: Considerable variation in the prevalence of childhood asthma and its symptoms (wheezing) has been observed in previous studies and there is evidence that the prevalence has been increasing over time. Methods: We have systematically reviewed the reported prevalence and time trends of wheezing symptoms among children, worldwide and within the same country over time. All studies comprising more than 1000 persons and meeting certain other quality criteria published over a 16-year period, between January 1990 and December 2005, are reported and a comparison of ISAAC (International Study of Asthma and Allergies in Childhood) and non-ISAAC studies is made, in part as a way of expanding the power to examine time trends (the older studies tend to be non-ISAAC), but also to examine possible methodological differences between ISAAC and non-ISAAC questions. Results: A wide range of current prevalence of wheeze was observed between and within countries over time. The UK had the highest recorded prevalence of 32.2% in children aged 13–14 in 1994–5 and Ethiopia had the lowest prevalence, 1.7% in children aged 10–19 in 1996. All studies in Australia and the UK were compared using multiple logistic regression. ISAAC phase I and III studies reported significantly higher prevalence of current wheeze (OR = 1.638) compared with non-ISAAC studies, after adjusting for various other factors (country, survey year, age of child, parental vs child response to the survey). Australia showed a significantly higher prevalence of current wheezing (OR = 1.343) compared with the UK, there was a significant increase in the prevalence odds ratio per survey year (2.5% per year), a significant decrease per age of child (0.7% per year), and a significantly higher response in current wheezing if the response was self-completed by the child (OR = 1.290). These factors, when explored separately for ISAAC and non-ISAAC studies, showed very different results. In ISAAC studies, or non-ISAAC studies using ISAAC questions, there was a significant decrease in current wheezing prevalence over time (2.5% per year). In non-ISAAC studies, which tend to cover an earlier period, there was a significant increase (2.6% per year) in current wheezing prevalence over time. This is very likely to be a result of prevalence of wheezing increasing from the 1970s up to the early 1990s, but decreasing since then. Conclusion: The UK has the highest recorded prevalence of wheezing and Ethiopia the lowest. Prevalence of wheezing in Australia and the UK has increased from the 1970s up to the early 1990s, but decreased since then and ISAAC studies report significantly higher prevalences than non-ISAAC studies

    A asma na criança e no adolescente brasileiro: contribuição do International Study of Asthma and Allergies in Childhood (ISAAC)

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    Objective:To assess asthma among Brazilian pediatric population applying the International Study of Asthma and Allergies in Childhood (ISAAC), an internationally standardized and validated protocol.Data sources:ISAAC was conceived to maximize the value of epidemiologic studies on asthma and allergic diseases, establishing a standardized method (self-applicable written questionnaire and/or video questionnaire) capable to facilitate the international collaboration. Designed to be carried out in three successive and dependent phases, the ISAAC gathered a casuistic hitherto unimaginable in the world and in Brazil. This review included data gathered from ISAAC official Brazilian centers and others who used this method.Data synthesis:At the end of the first phase, it has been documented that the prevalence of asthma among Brazilian schoolchildren was the eighth among all centers participating all over the world. Few centers participated in the second phase and investigated possible etiological factors, especially those suggested by the first phase, and brought forth many conjectures. The third phase, repeated seven years later, assessed the evolutionary trend of asthma and allergic diseases prevalence in centers that participated simultaneously in phases I and III and in other centers not involved in phase I.Conclusions:In Brazil, the ISAAC study showed that asthma is a disease of high prevalence and impact in children and adolescents and should be seen as a Public Health problem. Important regional variations, not well understood yet, and several risk factors were found, which makes us wonder: is there only one or many asthmas in Brazil?Objetivo:Evaluar el asma en la población pediátrica brasileña por el protocolo del International Study of Asthma and Allergies in Childhood (ISAAC), internacionalmente estandarizado y validado.Fuentes de datos : El ISAAC, idealizado para maximizar el valor de estudios epidemiológicos en asma y enfermedades alérgicas, estableció un método estandarizado (cuestionario escrito autoaplicable y/o video-cuestionario) capaz de facilitar la colaboración internacional. Concebido para realizarse en tres etapas sucesivas y dependientes, el ISAAC reunió una casuística hasta entonces inimaginable en el mundo y en Brasil. En esta visión, se reunieron los datos de centros brasileños oficiales del ISAAC y de otros que emplean su método.Síntesis de los datos:Finalizada la primera etapa, la prevalencia de asma entre escolares brasileños fue documentada como la octava en magnitud entre todos los centros participantes del estudio. Los pocos centros involucrados en la segunda etapa investigaron posibles factores etiológicos, especialmente aquellos sugeridos por los resultados de la primera etapa, y generaron muchas especulaciones. La tercera etapa, repetida tras siete años, evaluó la tendencia evolutiva de la prevalencia de asma y de las enfermedades alérgicas en los centros participantes simultáneamente en las etapas I y III y determinó la prevalencia en otros no involucrados en la etapa I.Conclusiones:En Brasil, el ISAAC demostró, de modo definitivo, que el asma es una enfermedad de alta prevalencia e impacto en niños y adolescentes, debiendo ser encarada como problema de Salud Pública. Se encontraron importantes variaciones regionales, todavía no bien aclaradas, así como diversos factores de riesgo, lo que nos hace cuestionar: ¿hay en Brasil una o muchas asmas?Objetivo:Avaliar a asma na população pediátrica brasileira pelo protocolo do International Study of Asthma and Allergies in Childhood (ISAAC), internacionalmente padronizado e validado.Fontes de dados:O ISAAC, idealizado para maximizar o valor de estudos epidemiológicos em asma e doenças alérgicas, estabeleceu um método padronizado (questionário escrito autoaplicável e/ou vídeo-questionário) capaz de facilitar a colaboração internacional. Concebido para ser realizado em três fases sucessivas e dependentes, o ISAAC reuniu uma casuística até então inimaginável no mundo e no Brasil. Nesta revisão, reuniram-se os dados de centros brasileiros oficiais do ISAAC e de outros que empregaram o seu método.Síntese dos dados:Finalizada a primeira fase, a prevalência de asma entre escolares brasileiros foi documentada como a oitava em magnitude entre todos os centros participantes do estudo. Os poucos centros envolvidos na segunda fase investigaram possíveis fatores etiológicos, especialmente aqueles sugeridos pelos resultados da primeira fase, e geraram muitas especulações. A terceira fase, repetida após sete anos, avaliou a tendência evolutiva da prevalência de asma e das doenças alérgicas nos centros participantes simultaneamente das fases I e III e determinou a prevalência em outros não envolvidos na fase I.Conclusões:No Brasil, o ISAAC demonstrou, de forma definitiva, que a asma é uma doença de alta prevalência e impacto em crianças e adolescentes, devendo ser encarada como problema de Saúde Pública. Encontraram-se importantes variações regionais, ainda não bem esclarecidas, assim como diversos fatores de risco, o que traz a questão: há no Brasil uma ou muitas asmas?Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM) Departamento de PediatriaUNIFESP, EPM, Depto. de PediatriaSciEL

    Ambient particulate pollution and the world-wide prevalence of asthma, rhinoconjunctivitis and eczema in children: Phase One of the International Study of Asthma and Allergies in Childhood (ISAAC)

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    Objectives: To investigate the effect of ambient particulate matter on variation in childhood prevalence of asthma, rhinoconjunctivitis and eczema. Methods: Prevalences of asthma, rhinoconjunctivitis and eczema obtained in Phase One of the International Study of Asthma and Allergies in Childhood (ISAAC) were matched with city-level estimates of residential PM10 obtained from a World Bank model. Associations were investigated using binomial regression adjusting for GNP per capita and for clustering within country. For countries with more than one centre, a two stage meta-analysis was carried out. The results were compared with a meta-analysis of published multi-centre studies. Results: Annual concentrations of PM₁₀ at city level were obtained for 105 ISAAC centres in 51 countries. After controlling for GNP per capita, there was a weak negative association between PM₁₀ and various outcomes. For severe wheeze in 13-14-year-olds, the OR for a 10 μg/m³ increase in PM₁₀ was 0.92 (95 CI 0.84 to 1.00). In 24 countries with more than one centre, most summary estimates for within-country associations were weakly positive. For severe wheeze in 13-14-year-olds, the summary OR for a 10 μg/m³ increase in PM₁₀ was 1.01 (0.92 to 1.10). This result was close to a summary OR of 0.99 (0.91 to 1.06) obtained from published multi-centre studies. Conclusions: Modelled estimates of particulate matter at city level are imprecise and incomplete estimates of personal exposure to ambient air pollutants. Nevertheless, our results together with those of previous multi-centre studies, suggest that urban background PM₁₀ has little or no association with the prevalence of childhood asthma, rhinoconjunctivitis or eczema either within or between countries

    K-band spectroscopy of IGR J16358-4726 and IGR J16393-4643: two new symbiotic X-ray binaries

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    Symbiotic X-ray Binaries (SyXBs) are a recently discovered subclass of Low Mass X-ray Binaries. Their growing number makes them an important evolutionary channel of X-ray Binaries. Our goal is to perform spectral analysis and classification of the proposed counterparts to IGR J16358-4726 and IGR J16393-4643 and to establish their nature as X-ray systems. We used the ESO/UT1 ISAAC spectrograph to observe the proposed counterparts to the two sources, obtaining K-band medium resolution spectra (R = 500) with a S/N > 140. Data reduction was performed with the standard procedure. We classified them by means of comparison with published atlases. We performed SED fitting in order to refine the spectral classification. The two counterparts clearly exhibit the typical features of late-type stars, notably strong CO absorption bands in the red part of the spectrum. With information from previous X-ray studies, we classify the two systems as two new members of the SyXB class. For IGR J16393-4643, we considered the most probable counterpart to the system, although three other objects cannot be completely discarded. For this system, we compared our findings with available orbital solutions, constraining the orbital parameters and the mass of the companion star. By including two more systems, we increased to eight the number of known SyXBs, which emerges as a non-negligible category of galactic X-ray binaries.Comment: 7 pages, 3 figures, 4 tables; this version includes referee's comments and language editing. Accepted for publication in Astronomy and Astrophysics

    An investigation of development appraisal methods employed by valuers and appraisers in small and medium sized practices in Brazil

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    Purpose – Whilst the real estate development appraisal practices of large national and international real estate companies are well understood, relatively little is known about how development appraisals are conducted by indigenous appraisers and valuers in developing countries. The purpose of this paper is to investigate how development appraisal is conducted in Brazil, compared to the UK, focusing primarily on the methods employed by small- and medium-sized real estate practices and their appraisers to appraise the viability of commercial real estate developments in the State of Sao Paulo. Design/methodology/approach – The study employs a two phase Delphi Method to capture and analyse empirical data from small- and medium-sized real estate appraisers in Brazil. Using the long established and relatively transparent UK Residual Method of development appraisal as a template against which to compare Brazilian appraisal methods, guidance and practice. To understand how indigenous development appraisers operate the Brazilian development appraisal methods, the research was conducted in Portuguese by a bi-lingual real estate expert who was familiar with both UK and Brazilian practice. Findings – The research establishes that appraisers working for small- and medium -sized real estate practices in Brazil rarely use the Residual Method. Instead, they employ a range of methods, the choice of which is heavily influenced by the availability of comparable market data, with Direct Comparison of market data and the Capitalisation of Income being the methods of choice when sufficient comparable evidence is available. Appraisers rarely employ the Residual Method as the principal development appraisal technique, using instead the Comparative Method and Discounted Cash Flow (DCF) analysis. Land prices are usually agreed or already known and developer’s profit is usually determined using DCF analysis and is highly sensitive to fluctuations in construction costs. Research limitations/implications – The research engaged with a small number of appraisers and valuers in small- and medium-sized practices in the State of Sao Paulo using a two-phase Delphi Method. The long established UK Residual Method of development appraisal was used as a template against which to compare practice in Sao Paulo State. There is potential therefore to replicate the research in other Brazilian States and transfer the methodology to other developing countries. Practical implications – In Brazil, when development land in urban areas is acquired on the basis of plot exchange, land is often sold at less than market value and the original landowner retains an equity stake in the development and shares in the development overage. The practice of “permuta física”, giving landowners the freehold of part of the development, or “permuta financeira”, whereby the landowner receives an enhanced land price, indexed against development value, is of potential relevance to the UK and other developed countries that need help in urban unlocking land markets

    Ices in Star-Forming Regions: First Results from VLT-ISAAC

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    The first results from a VLT-ISAAC program on L- and M-band infrared spectroscopy of deeply-embedded young stellar objects are presented. The advent of 8-m class telescopes allows high S/N spectra of low-luminosity sources to be obtained. In our first observing run, low- and medium-resolution spectra have been measured toward a dozen objects, mostly in the Vela and Chamaeleon molecular clouds. The spectra show strong absorption of H2O and CO ice, as well as weak features at `3.47' and 4.62 mu. No significant solid CH3OH feature at 3.54 mu is found, indicating that the CH3OH/H2O ice abundance is lower than toward some massive protostars. Various evolutionary diagnostics are investigated for a set of sources in Vela.Comment: 8 pages, 4 figures, to appear in The Origins of Stars and Planets: the VLT View, eds. J. Alves, M. McCaughrean (Springer Verlag

    M-Band Spectra of Dust Embedded Sources at the Galactic Center

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    The goal of the present paper is to investigate the circumstellar material around the brightest dust-enshrouded sources in the central stellar cluster of the Milky Way. Observations have been carried out at the European Southern Observatory's Very Large Telescope on Paranal, Chile. We have used the long wavelength (LWS3) low resolution (LR) spectroscopic mode of the ISAAC camera at the VLT in the spectral range of the M filter from 4.4micron to 5.1micron. The use of a slit width of 0.6" implied a spectral resolution of R=l/Dl=800 (Dv=375 km/s). These observations resulted in M-band spectra of 15 bright sources in the central stellar cluster of the Milky Way. In addition to gaseous 12^CO (4.666 micron) and 13^CO (4.77 micron) vibration-rotational absorptions, we detect a strong absorption due to a mixture of polar and apolar CO ice (centered at 4.675 micron). In the shorter wavelength absorption wing there is an absorption feature due to XCN at 4.62 micron. The XCN absorption is strongest toward the M2 supergiant IRS7. We find that the extinctions due to material traced by the CO ice and the CO gas absorptions may be of comparable importance. Using the spectra of IRS2L and IRS16C we perform a first order correction of the line of sight absorption due to CO-ice and 13^CO gas. In combination with published hydrogen number density estimates from sub-mm CO(7-6) and FIR [OI] line data we obtain gas masses of the circumstellar shells of the order of 10^-3 and 10^-2 solar masses. This implies that in future spectra taken at high spectral and angular resolution the bright and dust embedded Galactic Center sources should show a substantial line absorption due to source intrinsic absorption.Comment: 23 pages, 9 figures, Accepted for publication in Ap

    A search for hydrogenated fullerenes in fullerene-containing planetary nebulae

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    Detections of C60 and C70 fullerenes in planetary nebulae (PNe) of the Magellanic Clouds and of our own Galaxy have raised the idea that other forms of carbon such as hydrogenated fullerenes (fulleranes like C60H36 and C60H18), buckyonions, and carbon nanotubes, may be widespread in the Universe. Here we present VLT/ISAAC spectra (R ~600) in the 2.9-4.1 microns spectral region for the Galactic PNe Tc 1 and M 1-20, which have been used to search for fullerene-based molecules in their fullerene-rich circumstellar environments. We report the non-detection of the most intense infrared bands of several fulleranes around ~3.4-3.6 microns in both PNe. We conclude that if fulleranes are present in the fullerene-containing circumstellar environments of these PNe, then they seem to be by far less abundant than C60 and C70. Our non-detections together with the (tentative) fulleranes detection in the proto-PN IRAS 01005+7910 suggest that fulleranes may be formed in the short transition phase between AGB stars and PNe but they are quickly destroyed by the UV radiation field from the central star.Comment: Accepted for publication in Astronomy & Astrophysics (7 pages, 3 figures, and 3 Tables
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