ABSTRACT
The development of the Grijalva-Usumacinta river basin exerts modifications on its discharge area. A sediment core was studied to reconstruct environmental changes and trace element contamination status during the past 45 years. 210Pb-derived mass accumulation rates indicate higher sediment input to the area since 1995, related to increased precipitation and floodings in the catchment area. Sediments show finer particles from the late 1970s on, likely related to dams construction upriver and/or land use changes. Heavy metal enrichment factors (EF < 2) suggest minimum contamination. Benthic foraminifera and redox-sensitive - elements (As, Ba, Co, Cr, Cu, Ni, Pb, V and Zn) indicate the sediments before 2000 were deposited under oxygenated conditions. Afterwards, environmental conditions changed and benthic foraminifera and dinocysts assemblages changed suggesting eutrophication and lower oxygen conditions during the last 20 years. Monitoring should be continued to assess eutrophication/hypoxic/pollution trends that could become deleterious to the marine biota.
Subject(s)
Metals, Heavy/analysis , Water Pollutants, Chemical/analysis , Environmental Monitoring , Geologic Sediments , Gulf of Mexico , RiversABSTRACT
El objetivo del presente estudio fue evaluar el efecto del peso corporal sobre indicadores bioproductivos en gallinas White Leghorn L33. Se estudiaron 192 gallinas ponedoras con 39 semanas de edad durante un período de seis semanas y con tres observaciones semanales. Se diseñaron dos grupos según peso vivo, con 96 gallinas cada uno (tres réplicas de 32 aves), teniendo el grupo 1 entre 1500-1600 g y el grupo 2 entre 1735-1820 g; este último correspondió al rango establecido para este híbrido con esa edad. Además de la viabilidad y mortalidad se determinaron las variables bioproductivas (producción, peso, tamaño, forma y grosor de la cáscara de los huevos), así como la proporción de sucios, manchados y cascados. En la última semana del estudio, se analizó la calidad interna del huevo (dimensión y color de clara y yema) y se calcularon los índices de yema, clara y Unidades Haugh. Se realizó una estadística descriptiva y se utilizaron las pruebas T de Student y Fisher (P < 0,05) para comparar las medias entre grupos. Se evidenciaron diferencias estadísticas significativas entre producción, peso y tamaño de los huevos para el grupo de mayor peso corporal. Asimismo, se comprobó mayor calidad interna del huevo (altura de clara y yema) en este segundo grupo. Sin embargo, no se evidenciaron diferencias significativas en la calidad externa de los huevos (sucios, manchados, cascados), pero sí en el grosor de la cáscara. Se concluye que el peso corporal influye directa y positivamente sobre los indicadores bioproductivos en gallinas White Leghorn L33.
The objective of this study was to evaluate the effect of the corporal weight on bioproductive indicators in White Leghorn L33 hens. They were studied 192 egg-laying hens with 39 weeks of age during a period of six weeks and with a frequency of three weekly observations. Two groups according to the alive weight with 96 hens each one (three replies of 32 birds) were designed, having the group 1 (1500-1600 g) and group 2 (17351820 g), and being this last group the established range for this crossbreed with that age. Besides of viability and mortality bioproductive variables (production, weight, size, form and nutshell thickness of the eggs) were determined, as well as the proportion of dirty, stained and cracked eggs. In the last week of study the internal quality (dimension and color of egg white and yolk) was analyzed and the yolk and white index and Haugh Units were calculated. Descriptive statistics was realized and the Student's t and Fisher tests (P < 0.05) were used to compare means between groups. Significant statistical differences among production, weight, and size of eggs for group of bigger corporal weight were evidenced. Likewise, bigger internal quality of the egg (height of the egg white and yolk) in this second group was demonstrated. However, significant differences in the external quality of the eggs (dirty, stained and cracked) were not evidenced, unlike in the nutshell thickness. It is concluded that corporal weight influences direct and positively on bioproductive indicators in White Leghorn L33 hens.
ABSTRACT
Se realizó un estudio de corte transversal, descriptivo, sobre las consultas atendidas por guardia de un hospital cabecera de una nueva área operativa del sur de la Ciudad de Salta (Argentina) de la que dependen 26 centros de salud y brinda cobertura a una población aproximada de 200 mil habitantes. Para la misma zona de cobertura se registraron la cantidad de caninos ingresados a la Dirección Municipal de Zoonosis para observación en base a las Planillas de Observaciones de Animales Mordedores, las que se habilitan cuando el denunciante se presenta en las oficinas del organismo con el requisito de presentar la denuncia policial o el certificado médico (del servicio público o privado). La distribución de la edad de los pacientes mordidos es fuertemente asimétrica positiva, lo que confirma que la población pediátrica es las más vulnerable al ataque de animales. Cuando se analizó la relación entre el sexo y los grupos de edad, no se encontró asociación entre estas variables para los grupos etareos de niños y adolescentes, de modo que la edad resultó independiente del sexo del Sánchez D. C.1-3 , Sánchez A. P.2 , Tolaba M.3 , Herrera Verduguez M.2 , Flores C.M2 . 1 Cátedra de Bioestadística. Fac. de Ciencias de la Salud. Consejo de Investigación. Universidad Nacional de Salta. 2 Hospital Papa Francisco. Salta. República Argentina. 3 Cátedra de Salud Pública y Epidemiología. Fac. de Ciencias Agrarias y Veterinarias. Universidad Católica de Salta. Dirección de Zoonosis Municipalidad de Salta. Trabajo recibido: 15 de Abril 2015 Aprobado:10 de Junio 2015 35 Revista de Salud Pública, (XIX) julio 2015 individuo mordido (χ2= 3,15; p=0,6764). En individuos de 20 o más años, las mujeres resultaron significativamente más afectadas que los hombres (χ2= 8,65; p=0,0033). En el periodo de tiempo estudiado, se obtuvo una razón de 1 animal mordedor observado según procedimiento, por cada 7 mordeduras atendidas en el hospital...
A descriptive, cross-sectional study was carried out based on consultations of patients seenin the emergency room of a central hospital in a new operational area in the south of the cityof Salta (Argentina) with 26 health centers reporting to it and offering coverage to about200 thousand inhabitants. For the same coverage area, we registered the number of dogsentered to the Municipal Offi ce of Zoonosis for observation, according to the ObservationCharts of Biter Animals which are enabled when the informer comes to the Offi ce andshows a police report or medical certifi cate (from public or private sector).Age distribution of bitten patients is strongly asymmetric-positive, which confi rms thatpediatric population is more vulnerable to animal attacks. When the relation betweensex and age groups was analyzed, no association was found between these variables forgroups of children and adolescents; so age was independent of the sex of the bitten person(χ2= 3.15; p=0.6764). In groups age 20 and older, women were signifi cantly more affectedthan men (χ2= 8.65; p=0.0033).In the period studied, a rate of 1 biter animal was observed according to the procedure,every 7 bites seen at the hospital...
Realizou-se uma pesquisa de corte transversal-descritivo em casos tratados pela guarda deum hospital principal de uma nova área operacional ao sul da cidade de Salta (Argentina),dos quais dependem 26 centros de saúde e fornece cobertura para uma população estimadade 200.000 habitantes. Para a mesma área de cobertura foi cadastrado o número de cãesadmitidos no Departamento Municipal de Zoonose para observação com base na análisedas Planilhas de Observação de Animais Mordedores, que são habilitadas quando odenunciante apresenta-se nos escritórios da agência com o requisito de apresentar umadenúncia policial ou atestado médico (serviço público ou privado).A distribuição etária dos pacientes mordidos é marcadamente assimétrica positiva,confi rmando que a população pediátrica é a mais vulnerável a ataques de animais. Quandoa relação entre sexo e grupos etários foi analisada, não evidenciou-se associação entreessas variáveis para as faixas etárias de crianças e adolescentes, por isso, a idade foiindependente do sexo do indivíduo mordido (χ2= 3,15; p=0,6764). Em pacientes de 20 oumais anos, as mulheres foram signifi cativamente mais afetadas que os homens (χ2= 8,65;p=0,0033).No período estudado, foi obtida uma proporção de 1 animal mordedor observado segundoo procedimento, para cada 7 mordidas tratadas no hospital...
Subject(s)
Humans , Male , Animals , Female , Argentina , Bites and Stings , Bites and Stings/epidemiology , Dogs , Zoonoses/epidemiologyABSTRACT
Three limestone slabs (approx. 20 cm2 each) were extracted from the El Tajin archaeological zone in Veracruz, Mexico. X-ray diffraction analysis revealed three components: calcite (81.2%), quartz (17.9%) and feldspar (0.9%). Calcite content by x-ray diffraction analysis was slightly higher than that determined by chemical reaction between the limestone sample and nitric acid. The latter analysis, carried out in triplicate, yielded a calcite content of 77.1%. Mean water absorption, density and porosity of the limestone samples were also determined. Dissolution of limestone samples was investigated using an experimental rainfall simulation chamber, in which the stone samples were irrigated with artificial rain matching the pH and the ionic composition with 40 rainfall samples collected at El Tajin from August 18, 2002, to April 9, 2003. According to calcium and bicarbonate net concentrations found in the effluent of the chamber, a chemical mechanism by which limestone at El Tajin is dissolved by acid rain is proposed. A model used to investigate the air transport pathways corresponding to precipitation events at El Tajin shows that air parcels come mainly from the Gulf of Mexico, although no directional preference is evident for acidic vs. non-acidic events.
Subject(s)
Acid Rain/adverse effects , Archaeology , Calcium Carbonate , Water Pollutants, Chemical/adverse effects , Air Movements , Aluminum Silicates , Bicarbonates/analysis , Calcium/analysis , Humans , Hydrogen-Ion Concentration , Mexico , Potassium Compounds , QuartzABSTRACT
The South American lungfish (Lepidosiren paradoxa) has well-developed lungs and highly reduced gills. To evaluate acid-base regulation, we applied hypercarbia while blood gases and pulmonary ventilation were measured for up to 48 h. Dorsal aortic blood was analyzed, and pulmonary ventilation was measured by pneumotachography. Two protocols were used: (1) normocarbia (control) followed by aquatic hypercarbia (7% CO2 approximately 49 mmHg), gas phase normocarbic; and (2) normocarbia (control) followed by combined aquatic/gas phase hypercarbia (7% CO2). Normocarbic values were pHa~7.5, Paco2 approximately 17 mmHg, and [HCO-3]pl approximately 22 mM. For protocol 1, the first hour of exposure increased Paco2 from 17.0 to 37.4 mmHg, and pHa fell to 7.21 and remained there for the rest of the experiment. At 3 h, pulmonary ventilation reached sixfold the normocarbic value but then decreased. For protocol 2, combined gas phase/water hypercarbia had a large effect on acid-base status. Thus, Paco2 increased gradually to 74 mmHg (pHa=7.15) at 48 h. At 3 h, ventilation reached a sixfold increase relative to normocarbic control but then rose further to a 60-fold peak at 6 h, followed by a gradual decline. As in some salamanders and air-breathing teleosts, there was no evidence of active extracellular modulation bicarbonate.
Subject(s)
Acid-Base Equilibrium/physiology , Carbon Dioxide/blood , Fishes/physiology , Pulmonary Ventilation/physiology , Animals , Brazil , Hematocrit , Hydrogen-Ion Concentration , Oxygen/blood , Pulmonary Gas Exchange/physiology , Time FactorsABSTRACT
Wildfires in Mexico increased in 1998, compared to information for the last 6 years. The average number of wildfires in the Mexico City Metropolitan Area (MCMA) for this year (1998) were 58% (1916 events) more events than the 1992-1997 (average cases 1217 events). Mexico City affected area corresponds to 1.3% of the national affected area. The purpose of this paper is to evaluate the impact on the particles air quality due to the wildfire emissions at the MCMA and surrounding areas. Using the corresponding US EPA emission factors for wildfires, the tons of particulate matter, nitrogen oxides, carbon monoxide, and total hydrocarbons emitted by this source for the MCMA case were obtained. The calculated emissions during wildfires were correlated with the levels of particles present in the atmosphere. A comparison of the concentration levels of particles, both as PM10 as well as TSP, were made for the years 1992-1998, during wet and dry season, being March, April, and May the critical months due to the presence of wildfires. A good correlation is observed between particulate wildfire emissions and particulate air quality, being stronger for TSP. A clear impact on the particles air quality due to the increase of wildfires in 1998, is observed when this year is compared with 1997, presenting an increment of 200-300% for some monitoring stations.
Subject(s)
Air Pollutants/analysis , Fires , Cities , Environmental Monitoring , Mexico , Particle Size , SmokeABSTRACT
The respiratory control in land vertebrates (Tetrapoda) is mainly linked to regulation of acid-base status, which involves peripheral and central chemoreceptors. The lungfish (Dipnoi) might constitute the sister group of all land vertebrates (Tetrapoda) and possess a combination of real lungs and reduced gills. In this context, we evaluated the possible presence of central respiratory chemoreceptors in the South American Lungfish, Lepidosiren paradoxa. Pulmonary ventilation and respiratory frequency increased significantly with reductions of CSF pH by means of mock CSF solutions. This suggests that Lepidosiren possess central acid-base receptors.
