RESUMO
Biogenic volatile organic compounds (BVOCs) from the Amazon forest region represent the largest source of organic carbon emissions to the atmosphere globally. These BVOC emissions dominantly consist of volatile and intermediate-volatility terpenoid compounds that undergo chemical transformations in the atmosphere to form oxygenated condensable gases and secondary organic aerosol (SOA). We collected quartz filter samples with 12 h time resolution and performed hourly in situ measurements with a semi-volatile thermal desorption aerosol gas chromatograph (SV-TAG) at a rural site ("T3") located to the west of the urban center of Manaus, Brazil as part of the Green Ocean Amazon (GoAmazon2014/5) field campaign to measure intermediate-volatility and semi-volatile BVOCs and their oxidation products during the wet and dry seasons. We speciated and quantified 30 sesquiterpenes and 4 diterpenes with mean concentrations in the range 0.01-6.04 ngm-3 (1-670ppqv). We estimate that sesquiterpenes contribute approximately 14 and 12% to the total reactive loss of O3 via reaction with isoprene or terpenes during the wet and dry seasons, respectively. This is reduced from ~ 50-70 % for within-canopy reactive O3 loss attributed to the ozonolysis of highly reactive sesquiterpenes (e.g., ß-caryophyllene) that are reacted away before reaching our measurement site. We further identify a suite of their oxidation products in the gas and particle phases and explore their role in biogenic SOA formation in the central Amazon region. Synthesized authentic standards were also used to quantify gas- and particle-phase oxidation products derived from ß-caryophyllene. Using tracer-based scaling methods for these products, we roughly estimate that sesquiterpene oxidation contributes at least 0.4-5 % (median 1 %) of total submicron OA mass. However, this is likely a low-end estimate, as evidence for additional unaccounted sesquiterpenes and their oxidation products clearly exists. By comparing our field data to laboratory-based sesquiterpene oxidation experiments we confirm that more than 40 additional observed compounds produced through sesquiterpene oxidation are present in Amazonian SOA, warranting further efforts towards more complete quantification.
RESUMO
La presente investigación trata sobre la prevalencia de maloclusión, en un grupo de niños de 27 escuelas rurales y urbanas de los departamentos de San Salvador, San Miguel y La Libertad. El estudio se realizó en Febrero y Marzo de 2003, en niños con edades de 9 a 15 años, de ambos sexos; este grupo totalizó 4990 niños observados, del cual 53.5 % son niñas y el 46.5% restante corresponde a los niños; En el departamento de San Salvador se observaron 2155niños que equivales al 43.2%, en el departamento de San Miguel (de los municipios de San Miguel, Chapeltique y Chinameca) se observó el 41.1% representados por 2051 escolares y en el departamento de La Libertad (municipio de Comasagua)se observaron 784 niños que equivalen 15.7% de la población total. El Objetivo general de la investigación es identificar la prevalencia de la maloclusión. La maloclusión que prevalece en la población en estudio es la Clase I de Angle, presentando un 49% del total de maloclusiones; la Clase II en un 21% y la Clase III en un 15%. De igual manera los objetivos específicos se observan en porcentajes, en cuanto a la mordida cruzada representa un 13% de total observado y la mordida profunda se representa en un 17%; en cuanto a mordida abierta anterior se observó el 6%, y la mordida abierta posterior se presentó con un 4%, los incisivos borde a borde se observaron en el 14% de la población. El apiñamiento dentario estuvo representado por el 66%, los diastemas por el 35%. En cuanto a malposición dentaria, la más frecuente es la rotación en un 76%. En un 6% de la población se observó pérdida de la primera molar permanente tanto en superior como en inferior, 3.9% de la primera molar permanente inferior y el 0.5% restante corresponde a la de la primera molar permanente superior.
This research deals with the prevalence of malocclusion in a group of children from 27 rural and urban schools in the departments of San Salvador, San Miguel and La Libertad. The study was carried out in February and March 2003, in children between the ages of 9 and 15, of both sexes; This group totaled 4,990 observed children, of which 53.5% are girls and the remaining 46.5% correspond to boys; In the department of San Salvador, 2,155 children were observed, equivalent to 43.2%, in the department of San Miguel (from the municipalities of San Miguel, Chapeltique and Chinameca) 41.1% were observed, represented by 2,051 schoolchildren and in the department of La Libertad ( Municipality of Comasagua) 784 children were observed, equivalent to 15.7% of the total population. The general objective of the research is to identify the prevalence of malocclusion. The prevailing malocclusion in the study population is Angle's Class I, presenting 49% of all malocclusions; Class II by 21% and Class III by 15%. In the same way, the specific objectives are observed in percentages, as for the cross bite it represents 13% of the total observed and the deep bite is represented in 17%; Regarding the anterior open bite, 6% were observed, and the posterior open bite was presented with 4%, the incisors edge to edge were observed in 14% of the population. Dental crowding was represented by 66%, the diastemas by 35%. Regarding dental malposition, the most frequent is rotation in 76%. In 6% of the population, loss of the first permanent molar was observed in both upper and lower teeth, 3.9% of the first lower permanent molar and the remaining 0.5% corresponded to that of the first permanent upper molar.
