Effect of urban vs. rural residence on the association between atopy and wheeze in Latin America: findings from a case-control analysis.

BACKGROUND: The association between atopy and asthma is attenuated in non-affluent populations, an effect that may be explained by childhood infections such as geohelminths. OBJECTIVE: To investigate the association between atopy and wheeze in schoolchildren living in urban and rural areas of Ecuador and examine the effects of geohelminths on this association. METHODS: We performed nested case-control studies among comparable populations of schoolchildren living in rural communities and urban neighbourhoods in the Province of Esmeraldas, Ecuador. We detected geohelminths in stool samples, measured recent wheeze and environmental exposures by parental questionnaire, and atopy by specific IgE (sIgE) and skin prick test (SPT) reactivity to aeroallergens. RESULTS: Atopy, particularly sIgE to house dust mite (HDM), was more strongly associated with recent wheeze in urban than rural schoolchildren: (urban, adj. OR 5.19, 95% CI 3.37-8.00, P < 0.0001; rural, adj. OR 1.81, 95%CI 1.09-2.99, P = 0.02; interaction, P < 0.001). The population fractions of wheeze attributable to atopy were approximately two-fold greater in urban schoolchildren: SPT to any allergen (urban 23.5% vs. rural 10.1%), SPT to HDM (urban 18.5% vs. rural 9.6%), and anti-HDM IgE (urban 26.5% vs. rural 10.5%), while anti-Ascaris IgE was related to wheeze in a high proportion of rural (49.7%) and urban (35.4%) children. The association between atopy and recent wheeze was attenuated by markers of geohelminth infections. CONCLUSIONS: Our data suggest that urban residence modifies the association between HDM atopy and recent wheeze, and this effect is explained partly by geohelminth infections

Rural to urban migration is associated with increased prevalence of childhood wheeze in a Latin-American city.

INTRODUCTION: The urbanisation process has been associated with increases in asthma prevalence in urban and rural areas of low-income and middle-income countries (LMICs). However, although rural to urban migration and migration between cities are considered important determinants of this process, few studies have evaluated the effects of internal migration on asthma in urban populations of LMICs. The present study evaluated the effects of internal migration on the prevalence of wheeze in an urban area of Latin America. METHODS: We did a cross-sectional analysis of 2510 schoolchildren living in the city of Esmeraldas, Ecuador. Logistic regression was used to analyse associations between childhood wheeze and different aspects of migration among schoolchildren. RESULTS: 31% of schoolchildren were migrants. Rural to urban migrants had a higher prevalence of wheeze, (adj.OR=2.01,95% CI1.30 to 3.01, p=0.001) compared with non-migrants. Age of migration and time since migration were associated with wheeze only for rural to urban migrants but not for urban to urban migrants. Children who had migrated after 3 years of age had a greater risk of wheeze (OR 2.51, 95% CI 1.56 to 3.97, p=0.001) than non-migrants while migrants with less than 5 years living in the new residence had a higher prevalence of wheeze than non-migrants (<3 years: OR=2.34, 95% CI 1.26 to 4.33, p<0.007 and 3-5 years: OR=3.03, 95% CI 1.49 to 6.15, p<0.002). CONCLUSIONS: Our study provides evidence that rural to urban migration is associated with an increase in the prevalence of wheeze among schoolchildren living in a Latin-American city. Age of migration and time since migration were important determinants of wheeze only among migrants from rural areas. A better understanding of the social and environmental effects of internal migration could improve our understanding of the causes of the increase in asthma and differences in prevalence between urban and rural populations

Cohort Profile: The Ecuador Life (ECUAVIDA) study in Esmeraldas Province, Ecuador.

The ECUAVIDA birth cohort is studying the impact of exposures to soil-transmitted helminth (STH) parasites and early-life microbial exposures on the development of atopy, allergic diseases and immune responses in childhood. A total of 2404 newborns were recruited between 2006 and 2009 in a public hospital serving the rural district of Quininde, Esmeraldas Province, in a tropical region of coastal Ecuador. Detailed measurements were done around the time of the birth, at 7 and 13 months and at 2 and 3 years, and data collection is ongoing at 5 and 8 years. Data being collected include questionnaires for: sociodemographic, lifestyle, psychosocial (at 4-6 years only) and dietary (at 6-7 years only) factors; childhood morbidity and clinical outcomes; stool samples for parasites; blood samples for DNA, measurements of vaccine responses and other measures of immune function/inflammation; and anthropometrics. Allergen skin prick test reactivity is done from 2 years and measures of airway function and inflammation at 8 years

A study on the construct validity of the Parent-Child Conflict Tactics Scale (CTSPC) in an urban population in Northeast Brazil

The Parent-Child Conflict Tactics Scale (CTSPC) is one of the most widely used instruments in the world for investigating domestic violence against children, but targeted use has proven inadequate given the phenomenon's complexity. This study focused on the factor structure of CTSPC scales in an urban population in Northeast Brazil. We conducted a cross-sectional study in a cohort of 1,370 children in Salvador, Bahia State. Factor analysis with promax oblique rotation was performed, and the Kuder-Richardson coefficient was calculated. Factor analysis showed a different distribution of items in the factors as compared to the original instrument. Violence showed a gradual profile in each factor. The Kuder-Richardson coefficient was 0.63 for factor 1, 0.59 for factor 2, and 0.42 for factor 3. The items behaved differently from the original instrument, corroborating international studies. These findings support proposing a resizing of the CTSPC

The course of specialization in public health in Rio de Janeiro, Brazil, from 1926 to 2006: lessons and challenges

<p>Abstract</p> <p>Background</p> <p>Public health, as a field of knowledge, depends on its professionals. Their education and training, therefore, is considered to be an important factor for the quality of health services. In Brazil, the Course of Specialization in Public Health of the National School of Public Health is one of the oldest in the country. The course has existed for over 80 years, during which it has had an eventful history, with modifications in its organization, interruptions in its delivery, threats to its survival and changes in the institutions hosting it, reflecting the wider transformation in Brazilian society and public life over that period.</p> <p>Methods</p> <p>In this article we analyse this course via its history, disciplines, organization and characteristics of the student body.</p> <p>Results</p> <p>Insights were gained into the advancement of public health in Brazil and the progress of education for professionals in this field was highlighted. The course has formed nearly 2000 specialists in public health.</p> <p>Conclusions</p> <p>An analysis of the course's history provides valuable lessons for other schools of public health trying to train professionals in developing countries.</p

Radiating Shear-Free Gravitational Collapse with Charge

We present a new shear free model for the gravitational collapse of a spherically symmetric charged body. We propose a dissipative contraction with radiation emitted outwards. The Einstein field equations, using the junction conditions and an ansatz, are integrated numerically. A check of the energy conditions is also performed. We obtain that the charge delays the black hole formation and it can even halt the collapse.Comment: 22 pages, 9 figures. It has been corrected several typos and included several references. Accepted for publication in GR

Análise comparativa do atendimento e tecnologia em 2 hotéis nos setores de recepção, reservas e governança / Comparative analysis of service and technology in 2 hotels in the reception, reservation and governance sectors

 No presente trabalho o objetivo geral é um estudo de caso, abordando a evolução e inovação no setor hoteleiro no Brasil, será relatado como os hotéis têm inovado, buscando melhorias nos seus processos, desde a solicitação da reserva, ao atendimento dos hospedes nos hotéis. Será apresentado um estudo comparativo, de 02 hotéis na região central de São Paulo- SP, detalhando, os processos de cada setor desde a solicitação da reserva, ao processo de liberação dos apartamentos, em nenhum dos hotéis foi observado reclamações referente ao uso das ferramentas inovadoras, porém é possível notar ao implementar essas ferramentas toda a experiência vivida pelo cliente no hotel será modificada. 

Impact of early life geohelminths on wheeze, asthma, and atopy in Ecuadorian children at 8 years.

BACKGROUND: Early-lifeexposures to geohelminths may protect against development of wheeze/asthma and atopy. OBJECTIVE: Study effect of maternal geohelminths and infections in children during the first 5 years on atopy, wheeze/asthma, and airways reactivity/inflammation at 8 years. METHODS: Birth cohort of 2,404 neonates followed to 8 years in rural Ecuador. Data on wheeze/asthma were collected by questionnaire and atopy by skin prick test (SPT) reactivity to 9 allergens. We measured airways reactivity to bronchodilator, fractional exhaled nitric oxide (FeNO), and nasal eosinophilia. Stool samples were examined for geohelminths by microscopy. RESULTS: 1,933 (80.4%) children were evaluated at 8 years. Geohelminths were detected in 45.8% of mothers and 45.5% of children to 5 years. Frequencies of outcomes at 8 years were: wheeze (6.6%), asthma between 5 and 8 years (7.9%), SPT (14.7%), airways reactivity (10%), and elevated FeNO (10.3%) and nasal eosinophilia (9.2%). Any maternal geohelminth was associated with reduced SPT prevalence (OR 0.72).Childhood Trichuris trichiura infectionsduring the first 5 years were associated with reduced wheeze (OR 0.57) but greater parasite burdens with Ascaris lumbricoidesat 5 years were associated with increased wheeze (OR 2.83) and asthma (OR 2.60). Associations between maternal geohelminths and wheeze/asthma were modified by atopy. Parasite-specificeffects on wheeze/asthma and airways reactivity and inflammation were observed in non-atopic children. CONCLUSIONS: Our data provide novel evidence for persistent effects of in utero geohelminth exposures on childhood atopy but highlight the complex nature of the relationship between geohelminths and the airways. Registered as an observational study (ISRCTN41239086)

Characteristic Evolution and Matching

I review the development of numerical evolution codes for general relativity based upon the characteristic initial value problem. Progress in characteristic evolution is traced from the early stage of 1D feasibility studies to 2D axisymmetric codes that accurately simulate the oscillations and gravitational collapse of relativistic stars and to current 3D codes that provide pieces of a binary black hole spacetime. Cauchy codes have now been successful at simulating all aspects of the binary black hole problem inside an artificially constructed outer boundary. A prime application of characteristic evolution is to extend such simulations to null infinity where the waveform from the binary inspiral and merger can be unambiguously computed. This has now been accomplished by Cauchy-characteristic extraction, where data for the characteristic evolution is supplied by Cauchy data on an extraction worldtube inside the artificial outer boundary. The ultimate application of characteristic evolution is to eliminate the role of this outer boundary by constructing a global solution via Cauchy-characteristic matching. Progress in this direction is discussed.Comment: New version to appear in Living Reviews 2012. arXiv admin note: updated version of arXiv:gr-qc/050809

Sampling strategies to measure the prevalence of common recurrent infections in longitudinal studies

<p>Abstract</p> <p>Background</p> <p>Measuring recurrent infections such as diarrhoea or respiratory infections in epidemiological studies is a methodological challenge. Problems in measuring the incidence of recurrent infections include the episode definition, recall error, and the logistics of close follow up. Longitudinal prevalence (LP), the proportion-of-time-ill estimated by repeated prevalence measurements, is an alternative measure to incidence of recurrent infections. In contrast to incidence which usually requires continuous sampling, LP can be measured at intervals. This study explored how many more participants are needed for infrequent sampling to achieve the same study power as frequent sampling.</p> <p>Methods</p> <p>We developed a set of four empirical simulation models representing low and high risk settings with short or long episode durations. The model was used to evaluate different sampling strategies with different assumptions on recall period and recall error.</p> <p>Results</p> <p>The model identified three major factors that influence sampling strategies: (1) the clustering of episodes in individuals; (2) the duration of episodes; (3) the positive correlation between an individual's disease incidence and episode duration. Intermittent sampling (e.g. 12 times per year) often requires only a slightly larger sample size compared to continuous sampling, especially in cluster-randomized trials. The collection of period prevalence data can lead to highly biased effect estimates if the exposure variable is associated with episode duration. To maximize study power, recall periods of 3 to 7 days may be preferable over shorter periods, even if this leads to inaccuracy in the prevalence estimates.</p> <p>Conclusion</p> <p>Choosing the optimal approach to measure recurrent infections in epidemiological studies depends on the setting, the study objectives, study design and budget constraints. Sampling at intervals can contribute to making epidemiological studies and trials more efficient, valid and cost-effective.</p