A global stochastic index for water quality: The case of the river Turia in Spain

Which are applicable in all Member States. Those directives specify a set of physical and chemical characteristics, which depend on the use the water is intended for, the parameters to be regularly controlled in a network of sampling points, and the limiting values of those parameters for each quality level. Hence, an administrative quality classification for each sampling point is obtained. This article proposes a stochastic quality index that takes into account the uncertainty surrounding the quality classification still remaining after the data have been observed. This stochastic index is built with the probability classification vector of each parameter. In order to obtain those vectors, a mixed-lognormal model is introduced and its statistical analysis developed. The methodology proposed here is then applied to the data observed in the La Presa station, one of the sampling points of the Spanish surface water quality network. Located on the river Turia, near the city of Valencia, its aim is to control the quality of water intended for the abstraction of drinking water. Its stochastic quality classification is obtained and compared with the legally applicable administrative one.     

Prolonged Waterlogging Reduces Growth and Yield in Broccoli Plants (Brassica oleracea var. italica)

The crop of broccoli in tropical regions is of great importance among flowering vegetables; however, the yield of this crop is severely impacted by climatic variations that can cause floods. In Tunja, Colombia, a study was carried out under greenhouse conditions in which the tolerance of broccoli plants to prolonged waterlogging was evaluated. One group of plants were kept under waterlogging conditions until most of them showed severe symptoms of chlorosis while another group was grown under regularly drained and watered soil conditions as a control. Waterlogging caused the death of 20% of the plants, reduced the height of the plants by 42.9%, the thickness of the stem by 42.1%, the foliar area by 87%, the chlorophyll content in the leaves by 96.6%, and the total dry weight per plant by 79.9%. The absolute and relative growth rates decreased by 80 and 24.4%, respectively. Waterlogging also prevented flower production and caused a 23.7% increase in the accumulation of biomass in roots but reduced it by 24.5% in leaves. Likewise, the net assimilation rate fell 72.3% when waterlogged and the values of allometric variables which express growth were altered by this stressor. Consequently, it can be inferred that these plants have a low tolerance to waterlogging; however, the most severe impact caused by waterlogging was the inability of plants to develop flowers. The lack of flowers is devastating due to their economic and commercial importance of broccoli, and they are the primary justification for the cultivation of these plants.

     

Seroepidemiology of beef and dairy herds and fetal study of Neospora caninum in Argentina

The purpose of the present work was to study the epidemiology of Neospora caninum in beef and dairy herds in the Humid Pampas of Argentina. The seroprevalence of N. caninum was evaluated in 2414 serum samples of cows from beef and dairy farms. An indirect fluorescent antibody test (IFAT) was used to determine specific antibodies. The sera was screened at a dilution >or=1:200 and >or=1:600 in cows with reproductive disease antecedents and without them, respectively. Cows without history of reproductive diseases from nine beef and fifteen dairy farms were grouped according to the percentage (> or or 相似文献   

Diterpenoids from Cascarilla (Croton eluteria Bennet)

Cascarilla is a commercially available and cheap source of polyfunctionalized diterpenoids belonging to the clerodane structural type. In addition to the bitter triol cascarillin, 10 additional new diterpenoids (eluterins A-J) have been isolated and characterized by spectroscopic means. Structural diversity within cascarilla clerodanes involves mainly the linkage between the carbocyclic and the heterocyclic moieties and the functionalization of C-3, C-4, and C-6 of the decalin core. Cascarillin was shown to be a mixture of interconverting gamma-lactols and not a gamma-hydroxyaldehyde as previously reported.     

Use of geophysical methods for the study of sandy soils under Campinarana at the National Park of Viruá, Roraima state,Brazilian Amazonia

Purpose

The vegetation of the Campinaranas occurs in humid areas with hydromorphic sandy soils at the Amazon region. Thus, the determination and in situ monitoring of moisture content in Campinarana soils, besides the detection of subsurface layers are key measures for studying these soil–vegetation systems. Also, the application of ground penetrating radar (GPR) in deep sandy sedimentary sequence of Amazonia is a promising tool to enhance the knowledge on depositional and soil formation features.

Materials and methods

We studied representative soils of the Campinaranas at the National Park of Viruá, state of Roraima (Brazilian Amazonia), through the use of geophysical methods (soil moisture sensors and GPR). The study was applied in four sandy soils. Besides chemical and physical analysis of soils, soil moisture sensors were installed for monitoring during an entire hydrological year (2010/2011), and performed the calibration of sensors , coupled with imaging of the soil along transects with GPR.

Results and discussion

As a result of calibration of the soil moisture sensors we obtained a general equation with an R ² greater than 0.9. There is an influence of soil moisture content and soil temperature in the distribution of vegetation types in Campinaranas. The use of GPR identified some determinants characteristics in these soils for the differentiating the Campinaranas, represented by spodic and C horizons.

Conclusions

The spodic horizons in soils under Forest Campinarana provided potential errors in the determination of soil moisture, requiring calibration data for the precise use of this device. The investigation of the soil through the GPR showed interesting results, which allowed continuous visualization of the main soil horizons along transects in the phytophysiognomies of Campinaranas.     

Biomonitoring and Sourcing Toxic Elements Using Vascular Epiphytes of the Tillandsia Genus in the Mining Region of Taxco de Alarcón,Guerrero, Southern Mexico

Water, Air, &; Soil Pollution - The concentration of As, Pb, Cd, Zn, Fe, Mn, and Cu and the Sr and Pb isotopic compositions were determined in four species of the vascular epiphyte Tillandsia...