Search results for "altitud"
showing 10 items of 193 documents
Hyperendemic human fascioliasis in Andean valleys: an altitudinal transect analysis in children of Cajamarca province, Peru.
2011
Abstract A coprological survey including 476 2–18 year old school children from six rural localities between 2627 and 3061 m altitude was performed in Cajamarca province, Peru. Prevalences of fascioliasis ranging from 6.7 to 47.7% (mean 24.4%) proved to be the highest so far recorded in that human hyperendemic area. Higher prevalences in females and in the 2–5 year old group were not significant. Intensities ranged from 24 to 864 eggs per gram (arithmetic mean: 113; geometric mean: 68), the majority shedding less than 100, and without significant differences according to gender or age group. Fasciola hepatica was the most common helminth within a spectrum of 11–12 protozoan and 9–11 helmint…
Fascioliasis and Intestinal Parasitoses Affecting Schoolchildren in Atlixco, Puebla State, Mexico: Epidemiology and Treatment with Nitazoxanide
2013
Background The Atlixco municipality, Puebla State, at a mean altitude of 1840 m, was selected for a study of Fasciola hepatica infection in schoolchildren in Mexico. This area presents permanent water collections continuously receiving thaw water from Popocatepetl volcano (5426 m altitude) through the community supply channels, conforming an epidemiological scenario similar to those known in hyperendemic areas of Andean countries. Methodology and Findings A total of 865 6–14 year-old schoolchildren were analyzed with FasciDIG coproantigen test and Lumbreras rapid sedimentation technique, and quantitatively assessed with Kato-Katz. Fascioliasis prevalences ranged 2.94–13.33% according to loc…
The UV Index on the Spanish Mediterranean Coast¶
2005
An analysis is made of measured ultraviolet erythemal solar radiation (UVER) data recorded during the year 2003 by the networks of the Catalan Weather Service and the Environment Department of Valencia (both on the Spanish Mediterranean coast). Results show a latitudinal variation at sea level, of 3-4% per degree and an increase with altitude of 10% per km. Based on these data the UV Index has been evaluated for the measuring stations. The maximum experimental value of the UV Index was around 9 during the summer, although higher values were recorded at two stations, one at the highest elevation and the other at the lowest latitude. The annual accumulated doses of irradiation on a horizontal…
Empirical study of extreme rainfall intensity in a semi-arid environment at different time scales
2014
Abstract Mediterranean environments are typical of semi-arid regions, dominated by episodes of torrential rain in which the critical variable is not the total rainfall, but the intensity. This paper studies the maximum rainfall intensities at different observation time scales, from 5 min to 24 h, over eastern Spain from 1994 to 2007. The statistical rainfall characteristics for each time scale are analysed and the effects of specific geographical factors – altitude, aspect and distance to the sea – for each observation interval are tested. The results show that extreme intensities are heavily dependent on the time scale. There are two important turning points in this trend, at 1 h and 6 h. …
Microcrustacean and Rotiferan Communities of Two Close Mediterranean Mountain Ponds, Lagunas de Bezas and Rubiales (Spain)
2010
ABSTRACT We compared two freshwater mountain ponds during an annual cycle by focusing on Rotifera and Crustacea. These ponds, Laguna de Bezas and Laguna de Rubiales, are located only 4.5 kilometers apart and share a similar altitude (ca. 1200 m.a.s.1) on the Iberian Mountain range, in Teruel (Spain). Bezas is near-permanent and dries out only in severe droughts; Rubiales is temporary, drying out periodically. They also show important differences in other limnological traits. Bezas has transparent water, harbors a fish population, and has a dense macrophyte cover, whereas Rubiales has elevated turbidity and neither fish nor macrophytes during most of the hydroperiod. These differences are pr…
Pheno-morphological and agronomic diversity among Scorpiurus muricatus (Fabaceae) natural populations collected in Sicily.
2009
SUMMARYPrickly scorpion's tail (Scorpiurus muricatus L.) is a self-reseeding annual legume widely distributed in natural pastures of the Mediterranean area and appreciated by farmers for its productivity, forage quality and palatability. Twenty-eight natural populations were collected throughout Sicily in 2005; two field experiments were carried out in 2005/06 in a hilly area of the Sicilian inland to assess the genetic variation based on pheno-morphological and agronomic characters. The pheno-morphological traits observed were analysed using a principal component analysis (PCA). The first four components of PCA (eigenvalues >1) explained 0·84 of the total variation. Similarities obtaine…
Effect of Cutting Size and Basal Heat on Rooting of Micromeria fruticulosa Stem Cuttings
2017
Micromeria fruticulosa (Bertol.) Grande is a small pulviniform shrub, belonging to the Labiates, and characterized by twisted stems and pink-purple flowers. Endemic to Campania and Sicily (Italy), M. fruticulosa grows from sea level to 600 m altitude. This specie might be considered an excellent native plant for landscape purposes in Mediterranean areas because of its long flowering period, extending from November to June, and its tolerance to heat and drought. The exploitation of wild plants for ornamental purposes implies knowledge on the factors influencing the propagation methods. Root development of stem cuttings of M. fruticulosa was investigated in relation to basal heat and cutting …
Habitat preferences of the Tawny owl (Strix aluco) in a Special Conservancy Area of eastern Spain.
2020
The Tawny Owl (Strix aluco) is the most abundant nocturnal raptor in Europe. It has been thoroughly studied in various regions, but its habitat preferences in Mediterranean environments remain poorly understood. With the aim to present novel information about this aspect of the ecology of the Tawny Owl, we established 115 survey stations in the Special Conservancy Area 'Sierras de Talayuelas y Aliaguilla' (Castilla-La Mancha region, eastern Spain) and carried out nocturnal surveys by recording spontaneous calls and vocal responses to call playbacks. We then assessed environmental characteristics (vegetation types, soil type, altitude, potential competitors, and anthropic disturbance) in are…
Soil water content assessment: Seasonal effects on the triangle method
2016
Among indirect estimations of the soil water content in the upper layer, the "triangle method" is based on the relationship between the optical and thermal features sensed via Earth Observation. These features are controlled by water content at surface and within root zone, but also by meteorological forcing including air temperature and humidity, and solar radiation. Night and day-time MODIS composite land-surface temperature (LST) allowed applying the thermal admittance version of the method; by taking into account the temporal admittance of the soil, this version was previously found achieving high accuracy in estimate the soil water content at high spatial resolution within a short time…
Structure of the altitude adapted hemoglobin of Guinea pig in the R2-state
2010
Background: Guinea pigs are considered to be genetically adapted to a high altitude environment based on the consistent finding of a high oxygen affinity of their blood. Methodology/Principal Findings: The crystal structure of guinea pig hemoglobin at 1.8 A u resolution suggests that the increased oxygen affinity of guinea pig hemoglobin can be explained by two factors, namely a decreased stability of the Tstate and an increased stability of the R2-state. The destabilization of the T-state can be related to the substitution of a highly conserved proline (P44) to histidine (H44) in the a-subunit, which causes a steric hindrance with H97 of the b-subunit in the switch region. The stabilizatio…