793 research outputs found
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
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
Cloning and expression of activation induced cytidine deaminase from Bos taurus'
Activation induced cytidine deaminase is an enzyme crucial to somatic hypermutation and gene conversion, processes that are essential for the diversification of Ig V genes. The bovine Ig repertoire appears to be diversified by mechanisms that are significantly different to those that operate in humans and mice. This study set out to test the hypothesis that differences in the organization, coding sequence, expression or genomic location of the bovine AICDA gene enables the encoded enzyme to catalyse the unusual Ig diversification mechanism seen in cattle as well as conventional antigen-driven mutation. Characterization of bovine AICDA excluded the first two possibilities. AICDA expression was detected in lymphoid tissues from neonatal and older cattle, but AICDA cDNA could not be detected in muscle tissue. The pattern of gene expression did not therefore differ from that in other vertebrates. The AICDA cDNA was cloned and expressed successfully in Escherichia coli generating a phenotype consistent with the mutating action of this deaminase. Using a whole genome radiation hybrid panel, bovine AICDA was mapped to a region of bovine chromosome 5 syntenic with the location of human AICDA on chromosome 12. We conclude that the unusual nature of Ig diversification in cattle is unlikely to be attributable to the structure, sequence, activity or genomic location of bovine AICDA
Identity-Related Factors Protect Well-Being against Stigma for Transgender and Gender Non-Conforming People
This is the final version. Available on open access from Springer via the DOI in this recordAvailability of data and material: The materials and anonymized data for this study are available
upon request to the corresponding author.Code availability: The code for analyses conducted in this work are available upon request to the
corresponding author.Relatively little is known about identity-related resilience factors associated with well-being among transgender and gender non-conforming (TGNC) people. Drawing upon theory on stigma-related stress and resilience and work examining group identification as a buffer against discrimination, the aim of the current study was to model perceived discrimination, transgender identification, and gender identity affirmation as predictors of well-being for TGNC people. We also tested whether the positive association between gender identity affirmation and well-being might be explained by the benefits affirmation has for individual self-concept clarity. Participants were 105 TGNC individuals (42% transgender male, 39% transgender female, 19% other gender non-conforming [e.g., non-binary]) recruited through online forums and support groups in the United Kingdom and North America who completed an online survey including self-report measures of key constructs. Results from structural equation models demonstrated that: (1) experiences of discrimination were associated with lower well-being overall, but having a stronger transgender identity moderated this association; (2) after adjustment for discrimination and transgender identification, experiences of gender identity affirmation were independently associated with greater well-being for TGNC people. Secondary analyses demonstrated that gender identity affirmation was linked to well-being through reinforcing a strong, internalized sense of clarity about individual self-concept. Results are discussed in terms of the implications for TGNC health and well-being, particularly with regards to the need for supportive, identity-affirming social environments.University of Exete
Histological evidence for a supraspinous ligament in sauropod dinosaurs
Supraspinous ossified rods have been reported in the sacra of some derived sauropod dinosaurs. Although different hypotheses have been proposed to explain the origin ofthis structure, histological evidence has never been provided to support or reject any of them. In order to establish its origin, we analyse and characterize the microstructure of thesupraspinous rod of two sauropod dinosaurs from the Upper Cretaceous of Argentina. The supraspinous ossified rod is almost entirely formed by dense Haversian bone. Remains ofprimary bone consist entirely of an avascular tissue composed of two types of fibre-like structures, which are coarse and longitudinally (parallel to the main axis of the element) oriented. These structures are differentiated on the basis of their optical properties under polarized light. Very thin fibrous strands are also observed in some regions. These small fibres are all oriented parallel to one another but perpendicular to the element main axis. Histological features of the primary bone tissue indicate that the sacral supraspinous rod corresponds to an ossified supraspinous ligament. The formation of this structure appears to have been a non-pathological metaplastic ossification, possibly induced by the continuous tensile forces applied to the element.Fil: Cerda, Ignacio Alejandro. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en PaleobiologÃa y GeologÃa; Argentina. Universidad Nacional de RÃo Negro; ArgentinaFil: Casal, Gabriel. Universidad Nacional de la Patagonia; ArgentinaFil: MartÃnez, Rubén DarÃo. Universidad Nacional de la Patagonia ; ArgentinaFil: Ibiricu, Lucio Manuel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro Nacional Patagónico; Argentin
Activation-Induced Cytidine Deaminase Initiates Immunoglobulin Gene Conversion and Hypermutation by a Common Intermediate
Depending on the species and the lymphoid organ, activation-induced cytidine deaminase (AID) expression triggers diversification of the rearranged immunoglobulin (Ig) genes by pseudo V (ψV) gene- templated gene conversion or somatic hypermutation. To investigate how AID can alternatively induce recombination or hypermutation, ψV gene deletions were introduced into the rearranged light chain locus of the DT40 B-cell line. We show that the stepwise removal of the ψV donors not only reduces and eventually abolishes Ig gene conversion, but also activates AID-dependent Ig hypermutation. This strongly supports a model in which AID induces a common modification in the rearranged V(D)J segment, leading to a conversion tract in the presence of nearby donor sequences and to a point mutation in their absence
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)
Asthma in changing environments - chances and challenges of international research collaborations between South America and Europe - study protocol and description of the data acquisition of a case-control-study
<p>Abstract</p> <p>Background</p> <p>Asthma in children is an emerging public health problem in South America. So far, research in this part of the world is limited. This paper presents the methodology and description of the data acquisition of an asthma case-control study conducted in the Central South of Chile.</p> <p>Methods/Design</p> <p>A hospital-based case-control study about asthma (188 cases, 294 controls) in children (6-15 years) was carried out in Valdivia, Chile between November 2008 and December 2009. Data on asthma risk factors were collected by computer-assisted personal interview using validated questions from e.g. ISAAC phase II. Data on household dust exposure (endotoxin, allergen analyses), skin prick tests to most common allergens, stool examinations for parasitic infection, and blood samples (total IgE, genetics) were collected. Additionally, 492 randomly chosen blood donors were recruited in order to assess allele frequencies in the population of Valdivia.</p> <p>Discussion</p> <p>Overall 1,173 participants were contacted. Response was 82% among cases and 65% among controls. Atopic sensitization was high (78% among cases, 47% among controls). Cases had a statistically significantly (p < .0001) increased self-reported 12-month prevalence of symptoms of rhinitis (82% vs. 51%) and wheeze (68% vs. 16%). The study is well placed to address current hypotheses about asthma and its correlates in the South American context. Results of this study might help develop novel, innovative and individualized prevention strategies in countries in transition with respect to the South American context.</p
Morteros macroporosos para asentamiento y revestimiento.
The envelope of a building is responsible for its physical protection against external agents, including humidity and temperature. Thus, the present
work seeks to evaluate the effect of air entraining admixtures (AEA) in mortars for laying and coating to improve their physical and thermal
performances. The AEA generates macropores, interrupting the system of canaliculi that allows the capillary absorption of water. The AEA used is
based on biodegradable surfactant molecules of Linear Alkyl Benzene Sodium Sulfonate. Results compare physical tests (water absorption, capillary
coefficient, specific gravity, and mechanical strength), and thermal evaluation (thermal conductivity and specific heat) from two mortars mixtures
with varying levels of AEA. Scanning electron microscopy (SEM) of the pore system were also analysed. All mixtures studied presented higher
workability and cohesion, reduced thermal conductivity, decreased specific heat, and a reduction in the effects of water absorption, capillary elevation
and specific gravity (density). In this sense, the durability of mortars to humidity effect is potentially improved, along with several other properties.
Therefore, this work seeks to contribute to the quality of built environments, as well as to promote the technological development of cement-based
composites.Los cerramientos de un edificio son responsables de su protecci?n f?sica contra agentes externos, incluida la humedad y la temperatura. Por lo tanto,
el presente trabajo busca evaluar el efecto de los aditivos inclusores de aire (AEA) en los morteros para asentamiento y revestimiento para mejorar
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sus rendimientos f?sicos y t?rmicos. Los AEA generan macroporos, interrumpiendo el sistema de canal?culos que permiten la absorci?n capilar del
agua. El AEA utilizado se basa en mol?culas de un surfactante biodegradables - alquil benceno sulfonato de sodio lineal. Los resultados comparan
pruebas f?sicas (absorci?n de agua, coeficiente capilar, masa espec?fica y resistencia mec?nica) y evaluaci?n t?rmica (conductividad t?rmica y calor
espec?fico) de dos mezclas de morteros con niveles variables de AEA. Tambi?n se analiz? la microscop?a electr?nica de barrido (SEM) del sistema de
poros. Todas las mezclas estudiadas presentaron mayor trabajabilidad y cohesi?n, reducci?n de la conductividad t?rmica, disminuci?n del calor
espec?fico y reducci?n de los efectos de la absorci?n de agua, elevaci?n del capilar y gravedad espec?fica (densidad). En este sentido, la durabilidad
de los morteros al efecto de la humedad es potencialmente mejorada, junto con varias otras propiedades. Por lo tanto, este trabajo busca contribuir
a la calidad de los entornos construidos, as? como a promover el desarrollo tecnol?gico de compuestos de matriz cementicia
Study of Zγ events and limits on anomalous ZZγ and Zγγ couplings in pp̄ collisions at s=1.96TeV
We present a measurement of the Zγ production cross section and limits on anomalous ZZγ and Zγγ couplings for form-factor scales of Λ=750 and 1000 GeV. The measurement is based on 138 (152) candidates in the eeγ (μμγ) final state using 320(290)pb-1 of pp̄ collisions at s=1.96TeV. The 95% C.L. limits on real and imaginary parts of individual anomalous couplings are |h10,30Z|<0.23, |h20,40Z|<0.020, |h10,30γ|<0.23, and |h20,40γ|<0.019 for Λ=1000GeV. © 2005 The American Physical Society
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