1,695 research outputs found
Availability of timber housing construction techniques in Brazil
Se analiza la representatividad de las viviendas hechas en madera, en Brasil, indicando el porcentaje de cada técnica constructiva según la oferta de las empresas evaluadas. Los porcentajes que evidencian la frecuencia de utilización de las técnicas de construcción en madera fueron medidos por medio de dos metodologías aplicadas en las empresas: encuesta por entrevistas personales a sus propietarios y búsqueda de datos en sus sitios web. El método de encuestas por entrevistas evaluó 107 empresas brasileñas, y el de búsqueda en los sitios web alcanzó 207 empresas; se consiguió 50,95 y 98,57 %, respectivamente, de la población estimada. A pesar de esta diferencia, ambos métodos demostraron un escenario similar. Las entrevistas presentaron mayores costos de aplicación. Las técnicas contemporáneas están disponibles en más del 90 % de los productores brasileros. Las casas de tablas horizontales clavadas y las casas de tablas horizontales entre pilares fueron las que tuvieron mayores ofertas.This paper analyzes the representativeness of timber housing in Brazil, identifying the percentage of construction techniques offered by each evaluated company. Percentages that evidence the frequency of use of wooden building techniques were measured using two methods applied in the companies: survey through face-to-face interviews with owners and data search on their websites. The survey through interviews evaluated 107 Brazilian companies, while the data search included 207 companies, obtaining 50.95% and 98.57% of the estimated population, respectively. In spite of this difference, both methods showed a similar scenario. Interviews evidenced higher application costs. Contemporary techniques are available in more than 90% of Brazilian constructors. Houses with nailed horizontal boards and houses with horizontal wooden boards between columns were offered the most
DNA-based population density estimation of black bear at northern Mexico: A preliminary study
The analysis of deoxyribonucleic acid (DNA) microsatellites from hair samples obtained by the non-invasive method of traps was used to estimate the population density of black bears (Ursus americanus eremicus) in a mountain located at the county of Lampazos, Nuevo Leon, Mexico. The genotyping of bears was performed by multiplex polymerase chain reaction (PCR) using an average of two hairs for each animal. Samples were obtained with barbed wire placed at the traps, which contained food as bait. Multiplex PCR was performed with the GenomiPhiTM, G.E. kit and genotyping with an automated DNA sequencing machine (ABI 310 System). Allelic frequency, heterozygosis and exclusion probability of seven DNA microsatellites were calculated and analyzed with computer programs to determine the population density. Three of the microsatellites had a heterozygosis higher than 0.7 and the population density was calculated in at least 1 bear/km2.Keywords: Black bear, Ursus americanus, population size, DNA microsatellite, MexicoAfrican Journal of Biotechnology Vol. 12(2), pp. 103-10
Mosquitoes infected with dengue viruses in Brazil
Dengue epidemics have been reported in Brazil since 1985. The scenery has worsened in the last decade because several serotypes are circulating and producing a hyper-endemic situation, with an increase of DHF/DSS cases as well as the number of fatalities. Herein, we report dengue virus surveillance in mosquitoes using a Flavivirus genus-specific RT-Hemi-Nested-PCR assay. The mosquitoes (Culicidae, n = 1700) collected in the Northeast, Southeast and South of Brazil, between 1999 and 2005, were grouped into 154 pools. Putative genomes of DENV-1, -2 and -3 were detected in 6 mosquito pools (3.8%). One amplicon of putative DENV-1 was detected in a pool of Haemagogus leucocelaenus suggesting that this virus could be involved in a sylvatic cycle. DENV-3 was found infecting 3 pools of larvae of Aedes albopictus and the nucleotide sequence of one of these viruses was identified as DENV-3 of genotype III, phylogenetically related to other DENV-3 isolated in Brazil. This is the first report of a nucleotide sequence of DENV-3 from larvae of Aedes albopictus
Preparation and characterization of chloroaluminum phthalocyanine-loaded solid lipid nanoparticles by thermal analysis and powder X-ray diffraction techniques
Solid lipid nanoparticles (SLN) without drug and SLN loaded with chloroaluminum phthalocyanine (AlClPc) were prepared by solvent diffusion method in aqueous system and characterized by thermal analyses and X-ray diffraction (XRD) in this study. Determination of particle size, zeta potential (ZP), and encapsulation efficiency were also evaluated. SLN containing AlClPc of nanometer size with high encapsulation efficiency and ZP were obtained. The results indicated that the size of SLN loaded with AlClPc is larger than that of the inert particle, but ZP is not changed significantly with incorporation of the drug. In differential scanning calorimetry (DSC) curves, it was observed that the melting point of stearic acid (SA) isolated and in SLN occurred at 55 and 64 degrees C, respectively, suggesting the presence of different polymorphs. DSC also shows that the crystallinity state of SLN was much less than that of SA isolated. The incorporation of drug in SLN may have been favored by this lower crystallinity degree of the samples. XRD techniques corroborated with the thermal analytic techniques, suggesting the polymorphic modifications of stearic acid.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), BrazilFundacao de Amparo a Pesquisa do Estado de Sergipe-FAPITEC/SEMinisterio da SaudeSE
Author Correction: Whole-genome sequencing of 1,171 elderly admixed individuals from Brazil (vol 13, 1004, 2022)
Predictive models for mutations in mismatch repair genes: implication for genetic counseling in developing countries
<p>Abstract</p> <p>Background</p> <p>Lynch syndrome (LS) is the most common form of inherited predisposition to colorectal cancer (CRC), accounting for 2-5% of all CRC. LS is an autosomal dominant disease characterized by mutations in the mismatch repair genes mutL homolog 1 (MLH1), mutS homolog 2 (MSH2), postmeiotic segregation increased 1 (PMS1), post-meiotic segregation increased 2 (PMS2) and mutS homolog 6 (MSH6). Mutation risk prediction models can be incorporated into clinical practice, facilitating the decision-making process and identifying individuals for molecular investigation. This is extremely important in countries with limited economic resources. This study aims to evaluate sensitivity and specificity of five predictive models for germline mutations in repair genes in a sample of individuals with suspected Lynch syndrome.</p> <p>Methods</p> <p>Blood samples from 88 patients were analyzed through sequencing MLH1, MSH2 and MSH6 genes. The probability of detecting a mutation was calculated using the PREMM, Barnetson, MMRpro, Wijnen and Myriad models. To evaluate the sensitivity and specificity of the models, receiver operating characteristic curves were constructed.</p> <p>Results</p> <p>Of the 88 patients included in this analysis, 31 mutations were identified: 16 were found in the MSH2 gene, 15 in the MLH1 gene and no pathogenic mutations were identified in the MSH6 gene. It was observed that the AUC for the PREMM (0.846), Barnetson (0.850), MMRpro (0.821) and Wijnen (0.807) models did not present significant statistical difference. The Myriad model presented lower AUC (0.704) than the four other models evaluated. Considering thresholds of ≥ 5%, the models sensitivity varied between 1 (Myriad) and 0.87 (Wijnen) and specificity ranged from 0 (Myriad) to 0.38 (Barnetson).</p> <p>Conclusions</p> <p>The Barnetson, PREMM, MMRpro and Wijnen models present similar AUC. The AUC of the Myriad model is statistically inferior to the four other models.</p
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
High anti-SARS-CoV-2 antibody seroconversion rates before the second wave in Manaus, Brazil, and the protective effect of social behaviour measures: results from the prospective DETECTCoV-19 cohort
Background: The city of Manaus, Brazil, has seen two collapses of the health system due to the COVID-19 pandemic. We report anti-SARS-CoV-2 nucleocapsid IgG antibody seroconversion rates and associated risk factors in Manaus residents before the second wave of the epidemic in Brazil. Methods: A convenience sample of adult (aged ≥18 years) residents of Manaus was recruited through online and university website advertising into the DETECTCoV-19 study cohort. The current analysis of seroconversion included a subgroup of DETECTCoV-19 participants who had at least two serum sample collections separated by at least 4 weeks between Aug 19 and Oct 2, 2020 (visit 1), and Oct 19 and Nov 27, 2020 (visit 2). Those who reported (or had no data on) having a COVID-19 diagnosis before visit 1, and who were positive for anti-SARS-CoV-2 nucleocapsid IgG antibodies at visit 1 were excluded. Using an in-house ELISA, the reactivity index (RI; calculated as the optical density ratio of the sample to the negative control) for serum anti-SARS-CoV-2 nucleocapsid IgG antibodies was measured at both visits. We calculated the incidence of seroconversion (defined as RI values ≤1·5 at visit 1 and ≥1·5 at visit 2, and a ratio >2 between the visit 2 and visit 1 RI values) during the study period, as well as incidence rate ratios (IRRs) through cluster-corrected and adjusted Poisson regression models to analyse associations between seroconversion and variables related to sociodemographic characteristics, health access, comorbidities, COVID-19 exposure, protective behaviours, and symptoms. Findings: 2496 DETECTCoV-19 cohort participants returned for a follow-up visit between Oct 19 and Nov 27, 2020, of whom 204 reported having COVID-19 before the first visit and 24 had no data regarding previous disease status. 559 participants were seropositive for anti-SARS-CoV-2 nucleocapsid IgG antibodies at baseline. Of the remaining 1709 participants who were seronegative at baseline, 71 did not meet the criteria for seroconversion and were excluded from the analyses. Among the remaining 1638 participants who were seronegative at baseline, 214 showed seroconversion at visit 2. The seroconversion incidence was 13·06% (95% CI 11·52–14·79) overall and 6·78% (5·61–8·10) for symptomatic seroconversion, over a median follow-up period of 57 days (IQR 54–61). 48·1% of seroconversion events were estimated to be asymptomatic. The sample had higher proportions of affluent and higher-educated people than those reported for the Manaus city population. In the fully adjusted and corrected model, risk factors for seroconversion before visit 2 were having a COVID-19 case in the household (IRR 1·49 [95% CI 1·21–1·83]), not wearing a mask during contact with a person with COVID-19 (1·25 [1·09–1·45]), relaxation of physical distancing (1·31 [1·05–1·64]), and having flu-like symptoms (1·79 [1·23–2·59]) or a COVID-19 diagnosis (3·57 [2·27–5·63]) between the first and second visits, whereas working remotely was associated with lower incidence (0·74 [0·56–0·97]). Interpretation: An intense infection transmission period preceded the second wave of COVID-19 in Manaus. Several modifiable behaviours increased the risk of seroconversion, including non-compliance with non-pharmaceutical interventions measures such as not wearing a mask during contact, relaxation of protective measures, and non-remote working. Increased testing in high-transmission areas is needed to provide timely information about ongoing transmission and aid appropriate implementation of transmission mitigation measures. Funding: Ministry of Education, Brazil; Fundação de Amparo à Pesquisa do Estado do Amazonas; Pan American Health Organization (PAHO)/WHO.World Health OrganizationRevisión por pare
A survey on clinical presentation and nutritional status of infants with suspected cow' milk allergy
<p>Abstract</p> <p>Background</p> <p>Cow's milk is the most common food allergen in infants and the diagnosis of cow's milk allergy is difficult, even with the use of several diagnostic tests. Therefore, elimination diets and challenge tests are essential for the diagnosis and treatment of this disorder. The aim of this study is to report the clinical presentation and nutritional status of children evaluated by pediatric gastroenterologists for the assessment of symptoms suggestive of cow's milk allergy.</p> <p>Methods</p> <p>An observational cross-sectional study was performed among 9,478 patients evaluated by 30 pediatric gastroenterologists for 40 days in 5 different geographical regions in Brazil. Clinical data were collected from patients with symptoms suggestive of cow's milk allergy. The nutritional status of infants (age ≤ 24 months) seen for the first time was evaluated according to z-scores for weight-for-age, weight-for-height, and height-for-age. Epi-Info (CDC-NCHS, 2000) software was used to calculate z-scores.</p> <p>Results</p> <p>The prevalence of suspected cow's milk allergy in the study population was 5.4% (513/9,478), and the incidence was 2.2% (211/9,478). Among 159 infants seen at first evaluation, 15.1% presented with a low weight-for-age z score (< -2.0 standard deviation - SD), 8.7% with a low weight-for-height z score (< -2.0 SD), and 23.9% with a low height-for-age z score (< -2.0 SD).</p> <p>Conclusion</p> <p>The high prevalence of nutritional deficits among infants with symptoms suggestive of cow's milk allergy indicates that effective elimination diets should be prescribed to control allergy symptoms and to prevent or treat malnutrition.</p
The number of tree species on Earth
One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global ground sourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are ∼73,000 tree species globally, among which ∼9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness.
Please note an (erratum/corrigendum) for this article is available via https://www.pnas.org/doi/10.1073/pnas.220278411
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