268 research outputs found

    INIA 317: Altiplano, variedad de papa con buena adaptacion en la region altiplanica del Peru.

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    La papa constituye uno de los cultivos alimenticios más importantes en la agricultura familiar de la región andina del Perú. En las condiciones agroecológicas de esta región, uno de los factores más importantes que limita los niveles de producción y productividad de la papa es el clima adverso. Con el objetivo de lograr genotipos de papa; que además, de tener buena capacidad de rendimiento, respondan mejor a los nuevos estreses abióticos y bióticos provocados por el cambio climático, el Centro Internacional de la Papa realizó cruzamientos entre los cultivares nativos pertenecientes a Solanum tuberosum subsp. andigena. La evaluación de los genotipos se realizó a partir del año 2000 en las diferentes localidades de la región andina. Desde del año 2005, la Estación Experimental Illpa-Puno del Instituto Nacional de Innovación Agraria (INIA) y el Centro Internacional de la Papa (CIP) dentro de las actividades del Proyecto ALTAGRO, evaluaron un grupo de estos clones en diversas comunidades de la Región Altiplánica del Perú, a través de la metodología de selección participativa, con el objetivo de obtener una variedad de papa con alta capacidad productiva, adaptada a las condiciones climáticas de la Región Altiplánica y con aptitud para procesamiento en tunta. Como resultado de este trabajo de investigación se ha logrado seleccionar un genotipo de papa adaptada a la Región Altiplánica del Perú, con alto potencial de rendimiento y alto contenido de materia seca. Este genotipo de papa inicialmente identificado como el clon 399085.30 (B1C5041.30), actualmente es denominado variedad INIA 317 – ALTIPLAN

    Manejo del material de siembra de yuca (Manihot esculenta Crantz)

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    Several cassava trials were planted at CIAT to study the effect of the maturity of stem cuttings, depth of planting, cutting length, planting position and the angle of the cut on root yield. Cuttings from the top and middle part of vigorous 1-yr-old plants produced greater than root yields than those proceeding from the lower part of the plant or from older stem parts. Cuttings planted vertically 10, 20 and 30 cm deep do not affect the yield but do affect root distribution, the no. of roots/plant and the difficulty of harvesting; planting at 10 cm in depth was the most adequate. Twenty-cm long, selected and treated cuttings gave slightly higher yields than 40 or 60 cm ones. Cuttings placed vertically assure more rapid emergence, greater than percentage of germination, greater than yields and prevent lodging in comparison to those planted in a horizontal or inclined position. When the stems were cut rectangularly or bevel-edged, different rooting systems were produced; the former produced roots with a more uniform distribution; nevertheless, yield was not affected. Vertical planting, either with a straight or bevel-edged cut, gave greater than yields than horizontal planting. To obtain max yields, planting material should be selected from the middle part of mature, vigorous plants, cut at right angles 20 cm long and planted vertically 10 cm deep. (AS-CIAT)Se sembraron varios ensayos de yuca en el CIAT para estudiar el efecto de la madurez de las estacas, profundidad de siembra, longitud de la estaca, posicion de siembra y angulo de corte de la misma, en el rendimiento de las raices. Las estacas de la parte media y superior de plantas vigorosas de un ano de edad produjeron mayores rendimientos de raices que aquellas provenientes de la parte baja de la planta o de estacas viejas. Las estacas sembradas verticalmente a 10, 20 y 30 cm de profundidad no influyen en el rendimiento, pero afectan la distribucion de raices, el numero de raices/planta y la facilidad de cosecha; la siembra a 10 cm de profundidad fue la mas adecuada. Las mayores estacas de 20 cm de largo seleccionadas y tratadas dieron rendimientos ligeramente mayores que las de 40 o 60 cm. La siembra vertical de las estacas aseguro una emergencia mas rapida, un mayor porcentaje de germinacion, mayores rendimientos y previno el volcamiento de las plantas, en comparacion con la posicion horizontal o inclinada. El corte de la estaca en forma rectangular o en bisel produjo diferentes sistemas de enraizamiento; el primero produce raices mas uniformemente distribuidas; sin embargo, no afecta el rendimiento. La siembra vertical, ya sea con angulo de corte recto o en bisel, da mayores rendimientos que la siembra horizontal. Para obtener los rendimientos maximos, el material de siembra se debe seleccionar de la parte media de plantas vigorosas maduras, cortado en un angulo recto, en trozos de 20 cm de largo y sembrado verticalmente a 10 cm de profundidad. (RA-CIAT

    Active School Transport among Children from Canada, Colombia, Finland, South Africa, and the United States: A Tale of Two Journeys

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    Walking and biking to school represent a source of regular daily physical activity (PA). The objectives of this paper are to determine the associations of distance to school, crime safety, and socioeconomic variables with active school transport (AST) among children from five culturally and socioeconomically different country sites and to describe the main policies related to AST in those country sites. The analytical sample included 2845 children aged 9–11 years from the International Study of Childhood Obesity, Lifestyle and the Environment. Multilevel generalized linear mixed models were used to estimate the associations between distance, safety and socioeconomic variables, and the odds of engaging in AST. Greater distance to school and vehicle ownership were associated with a lower likelihood of engaging in AST in sites in upper-middle- and high-income countries. Crime perception was negatively associated to AST only in sites in high-income countries. Our results suggest that distance to school is a consistent correlate of AST in different contexts. Our findings regarding crime perception support a need vs. choice framework, indicating that AST may be the only commuting choice for many children from the study sites in upper-middle-income countries, despite the high perception of crime

    Clocking the formation of today's largest galaxies: Wide field integral spectroscopy of Brightest Cluster Galaxies and their surroundings

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    The formation and evolution of local brightest cluster galaxies (BCGs) is investigated by determining the stellar populations and dynamics from the galaxy core, though the outskirts and into the intracluster light (ICL). Integral spectroscopy of 23 BCGs observed out to 4 r_e is collected and high signal-to-noise regions are identified. Stellar population synthesis codes are used to determine the age, metallicity, velocity, and velocity dispersion of stars within each region. The intracluster light (ICL) spectra are best modeled with populations that are younger and less metal-rich than those of the BCG cores. The average BCG core age of the sample is 13.3±\pm 2.8 Gyr and the average metallicity is [Fe/H] = 0.30 ±\pm 0.09, whereas for the ICL the average age is 9.2±\pm3.5 Gyr and the average metallicity is [Fe/H] = 0.18±\pm0.16. The velocity dispersion profile is seen to be rising or flat in most of the sample (17/23), and those with rising values reach the value of the host cluster's velocity dispersion in several cases. The most extended BCGs are closest to the peak of the cluster's X-ray luminosity. The results are consistent with the idea that the BCG cores and inner regions formed quickly and long ago, with the outer regions and ICL forming more recently, and continuing to assemble through minor merging. Any recent star formation in the BCGs is a minor component, and is associated with the cluster cool core status.Comment: 22 pages, 21 figures, MNRAS, accepte

    Origin and Epidemiological History of HIV-1 CRF14_BG

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    This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Users must also make clear the license terms under which the work was published. CC BY Licence: http://creativecommons.org/licenses/by/4.0/Background: CRF14_BG isolates, originally found in Spain, are characterized by CXCR4 tropism and rapid disease progression. This study aimed to identify the origin of CRF14_BG and reconstruct its epidemiological history based on new isolates from Portugal.Methodology/Principal Findings: C2V3C3 env gene sequences were obtained from 62 samples collected in 1993–1998 from Portuguese HIV-1 patients. Full-length genomic sequences were obtained from three patients. Viral subtypes, diversity, divergence rate and positive selection were investigated by phylogenetic analysis. The molecular structure of the genomes was determined by bootscanning. A relaxed molecular clock model was used to date the origin of CRF14_BG. Geno2pheno was used to predict viral tropism. Subtype B was the most prevalent subtype (45 sequences; 73%) followed by CRF14_BG (8; 13%), G (4; 6%), F1 (2; 3%), C (2; 3%) and CRF02_AG (1; 2%). Three CRF14_BG sequences were derived from 1993 samples. Near full-length genomic sequences were strongly related to the CRF14_BG isolates from Spain. Genetic diversity of the Portuguese isolates was significantly higher than the Spanish isolates (0.044 vs 0.014, P,0.0001). The mean date of origin of the CRF14_BG cluster was estimated to be 1992 (range, 1989 and 1996) based on the subtype G genomic region and 1989 (range, 1984–1993) based on the subtype B genomic region. Most CRF14_BG strains (78.9%) were predicted to be CXCR4. Finally, up to five amino acids were under selective pressure in subtype B V3 loop whereas only one was found in the CRF14_BG cluster.Conclusions: CRF14_BG emerged in Portugal in the early 1990 s soon after the beginning of the HIV-1 epidemics, spread to Spain in late 1990 s as a consequence of IVDUs migration and then to the rest of Europe. CXCR4 tropism is a general characteristic of this CRF that may have been selected for by escape from neutralizing antibody response

    Particulate matter air pollution and cardiovascular disease: An update to the scientific statement from the American Heart Association

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    In 2004, the first American Heart Association scientific statement on “Air Pollution and Cardiovascular Disease” concluded that exposure to particulate matter (PM) air pollution contributes to cardiovascular morbidity and mortality. In the interim, numerous studies have expanded our understanding of this association and further elucidated the physiological and molecular mechanisms involved. The main objective of this updated American Heart Association scientific statement is to provide a comprehensive review of the new evidence linking PM exposure with cardiovascular disease, with a specific focus on highlighting the clinical implications for researchers and healthcare providers. The writing group also sought to provide expert consensus opinions on many aspects of the current state of science and updated suggestions for areas of future research. On the basis of the findings of this review, several new conclusions were reached, including the following: Exposure to PM less than 2.5 μm in diameter (PM2.5) over a few hours to weeks can trigger cardiovascular disease–related mortality and nonfatal events; longer-term exposure (eg, a few years) increases the risk for cardiovascular mortality to an even greater extent than exposures over a few days and reduces life expectancy within more highly exposed segments of the population by several months to a few years; reductions in PM levels are associated with decreases in cardiovascular mortality within a time frame as short as a few years; and many credible pathological mechanisms have been elucidated that lend biological plausibility to these findings. It is the opinion of the writing group that the overall evidence is consistent with a causal relationship between PM2.5 exposure and cardiovascular morbidity and mortality. This body of evidence has grown and been strengthened substantially since the first American Heart Association scientific statement was published. Finally, PM2.5 exposure is deemed a modifiable factor that contributes to cardiovascular morbidity and mortality

    Bacterial biogeography of adult airways in atopic asthma

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    Abstract Background Perturbations to the composition and function of bronchial bacterial communities appear to contribute to the pathophysiology of asthma. Unraveling the nature and mechanisms of these complex associations will require large longitudinal studies, for which bronchoscopy is poorly suited. Studies of samples obtained by sputum induction and nasopharyngeal brushing or lavage have also reported asthma-associated microbiota characteristics. It remains unknown, however, whether the microbiota detected in these less-invasive sample types reflect the composition of bronchial microbiota in asthma. Results Bacterial microbiota in paired protected bronchial brushings (BB; n = 45), induced sputum (IS; n = 45), oral wash (OW; n = 45), and nasal brushings (NB; n = 27) from adults with mild atopic asthma (AA), atopy without asthma (ANA), and healthy controls (HC) were profiled using 16S rRNA gene sequencing. Though microbiota composition varied with sample type (p < 0.001), compositional similarity was greatest for BB-IS, particularly in AAs and ANAs. The abundance of genera detected in BB correlated with those detected in IS and OW (r median [IQR] 0.869 [0.748–0.942] and 0.822 [0.687–0.909] respectively), but not with those in NB (r = 0.004 [− 0.003–0.011]). The number of taxa shared between IS-BB and NB-BB was greater in AAs than in HCs (p < 0.05) and included taxa previously associated with asthma. Of the genera abundant in NB, only Moraxella correlated positively with abundance in BB; specific members of this genus were shared between the two compartments only in AAs. Relative abundance of Moraxella in NB of AAs correlated negatively with that of Corynebacterium but positively with markers of eosinophilic inflammation in the blood and BAL fluid. The genus, Corynebacterium, trended to dominate all NB samples of HCs but only half of AAs (p = 0.07), in whom abundance of this genus was negatively associated with markers of eosinophilic inflammation. Conclusions Induced sputum is superior to nasal brush or oral wash for assessing bronchial microbiota composition in asthmatic adults. Although compositionally similar to the bronchial microbiota, the microbiota in induced sputum are distinct, reflecting enrichment of oral bacteria. Specific bacterial genera are shared between the nasal and the bronchial mucosa which are associated with markers of systemic and bronchial inflammation.https://deepblue.lib.umich.edu/bitstream/2027.42/144218/1/40168_2018_Article_487.pd

    Traffic-related air pollution and respiratory symptoms among asthmatic children, resident in Mexico City: the EVA cohort study

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    <p>Abstract</p> <p>Background</p> <p>Taffic-related air pollution has been related to adverse respiratory outcomes; however, there is still uncertainty concerning the type of vehicle emission causing most deleterious effects.</p> <p>Methods</p> <p>A panel study was conducted among 147 asthmatic and 50 healthy children, who were followed up for an average of 22 weeks. Incidence density of coughing, wheezing and breathing difficulty was assessed by referring to daily records of symptoms and child's medication. The association between exposure to pollutants and occurrence of symptoms was evaluated using mixed-effect models with binary response and poisson regression.</p> <p>Results</p> <p>Wheezing was found to relate significantly to air pollutants: an increase of 17.4 μg/m<sup>3 </sup>(IQR) of PM<sub>2.5 </sub>(24-h average) was associated with an 8.8% increase (95% CI: 2.4% to 15.5%); an increase of 34 ppb (IQR) of NO<sub>2 </sub>(1-h maximum) was associated with an 9.1% increase (95% CI: 2.3% to16.4%) and an increase of 48 ppb (IQR) in O<sub>3 </sub>levels (1 hr maximum) to an increase of 10% (95% CI: 3.2% to 17.3%). Diesel-fueled motor vehicles were significantly associated with wheezing and bronchodilator use (IRR = 1.29; 95% CI: 1.03 to 1.62, and IRR = 1.32; 95% CI: 0.99 to 1.77, respectively, for an increase of 130 vehicles hourly, above the 24-hour average).</p> <p>Conclusion</p> <p>Respiratory symptoms in asthmatic children were significantly associated with exposure to traffic exhaust, especially from natural gas and diesel-fueled vehicles.</p

    Residential exposure to motor vehicle emissions and the risk of wheezing among 7-8 year-old schoolchildren: a city-wide cross-sectional study in Nicosia, Cyprus

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    <p>Abstract</p> <p>Background</p> <p>Several studies have reported associations between respiratory outcomes in children and a range of self-reported, administrative or geographical indicators of traffic pollution. First-time investigation into the frequency of asthmatic symptoms among 7-8 year-old Cypriot children in 1999-2000 showed increased prevalence in the capital Nicosia compared to other areas. Geographical differences on an island the size of Cyprus may reflect environmental and/or lifestyle factors. This study investigates the relationship between self-reported symptoms and residential exposure to motor vehicle emissions among Nicosia schoolchildren.</p> <p>Methods</p> <p>The addresses of children in the metropolitan area of Nicosia who participated in the original survey (N = 1,735) were geo-coded and the level of exposure of each child was assessed using distance- and emission-based indicators (i.e. estimated levels of particulate matter and nitrogen oxides emissions due to motor vehicles on main roads around the residence). Odds ratios of wheezing and asthma diagnosis in relation to levels of exposure were estimated in logistic regression models adjusting for person-based factors, co-morbidity and intra-school clustering.</p> <p>Results</p> <p>We found an increased risk of wheezing at distances less than 50 m from a main road and/or only among those experiencing the highest levels of exposure. The strongest effect estimates were observed when exposure was defined in terms of the cumulative burden at all roads around the residence. Adjusted odds ratios for current wheezing were 2.33 (95% CI 1.27, 4.30) amongst the quartile of participants exposed to the highest levels of PM at all roads 50 m of their residence and 2.14 (95% CI 1.05, 4.35) for NOx, with no effect at intermediate levels of exposure. While the direction of effect was apparent at longer distances, differences were generally not statistically significant.</p> <p>Conclusions</p> <p>Children experiencing the highest burden of emissions in Nicosia seem to be at a higher risk of reporting asthmatic symptoms. Due to the small number of children residing at close proximity to main roads and lack of evidence of risk at intermediate levels of exposure or longer distances, the observed pattern alone does not explain the generally higher prevalence observed in urban Nicosia compared to other areas.</p
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