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Madrid, Spain

Martin M.P.,Institute Economia | Barreto L.,CSIC - Institute of Agricultural Sciences | Fernandez-Quintanilla C.,CSIC - Institute of Agricultural Sciences
Crop Protection | Year: 2011

Site-specific weed management implies detecting the location of weeds in order to generate maps of their spatial distribution. This information facilitates a more accurate application of herbicides, spraying them in the exact areas of weed growth and in the required doses. In order to explore the potential of commercial satellites to discriminate and map weeds, we used the information contained in high spatial resolution images acquired by the QuickBird satellite to assess the density of sterile oat (Avena sterilis) present in a winter barley field at two different dates (March and June). Our results confirmed the potential of using satellite images in the spectral discrimination of weed patches in infested fields. The results of binary logistic regressions showed that the best matches in the classification of three categories (low, medium, or high sterile oat densities) corresponded to the March image. QuickBird's March image provided reliable estimates of sterile oat patches in barley crops when weed density was relatively high (between 86% and 94% of agreement between predicted and observed densities). However, when weed densities were lower than 10 plants/m2 there were serious difficulties to distinguish them from weed-free zones (between 72 and 75% of global agreement in the classification) with large underestimation of medium density weed patches (10 plants/m2). This is a potential limitation considering than the thresholds used for herbicide application decisions are generally close to this density. However, the information obtained may still be useful for producing field maps to describe the spatial distribution of this weed. Moreover, these studies have provided valuable information on the best spectral regions and/or vegetation indices for approaching discrimination between sterile oat and cereal crops and the most suitable period for it. © 2011 Elsevier Ltd. Source


Cendon M.L.,Instituto Nacional de Tecnologia Agropecuaria | Sanz-Canada J.,Institute Economia | Lucena-Piquero D.,Independent Researcher
Spanish Journal of Agricultural Research | Year: 2014

A relevant topic investigated in ‘Local Agro-Food Systems’ studies (LAFS) is the key role of collective action in the dissemination of innovations and knowledge aimed at the organization of quality on a local scale. The scope of this article deals with the methodological tools for typifying the relationships made, in LAFS hosting a Protected Designation of Origin (PDO), between the relational social capital and the differential quality of firms. The objective of this work is to categorize the agro-industrial firms into hierarchies for implementing rural development policies, with respect to their technical and managerial advice relationships and their score achieved in terms of product and process quality. The study takes into account the LAFS of “Estepa” and “Sierra de Segura”, Andalusia (S Spain), corresponding to two important olive oil PDOs. The methodological approach comprises, firstly, the elaboration of a quality synthetic indicator on processes and products of the mills. Secondly, social network analysis is applied to the technical/managerial advice networks of the mills. Thirdly, a mill typology was established by means of factor analysis which employs quality and relational indicators. It is proved that the Regulatory Boards, as well as the second-step cooperatives, can assume a role of integrating poles with respect to the collective action developed in the LAFS, particularly in terms of dissemination of knowledge and innovations, which enhances the process and product quality of local firms. The existence of networks is a necessary condition to improve and homogenize the quality in a diffuse local agro-food structure. © 2014 Ministerio de Agricultura Pesca y Alimentacion. All Rights Reserved. Source


Care provided by relatives or friends to dependent people is a key process to promote wellbeing in Spanish society. This type of support has intense consequences over caregivers' lives. Comprehensive and multidisciplinary analyses are required to assess dependency effects over social network. In this paper we elaborate a classification of types of family care consequences over caregivers. We differentiate between positive or negative consequences, and between consequences affecting caregivers' health, economy and/or social relations. © 2010 Fundación Index. Source


Cheng T.,University of California at Davis | Riano D.,University of California at Davis | Riano D.,Institute Economia | Ustin S.L.,University of California at Davis
Remote Sensing of Environment | Year: 2014

Continuous wavelet analysis (CWA) has recently been applied to leaf-level spectroscopic data for quantifying foliar chemistry, but it is unclear how well or whether CWA can be applied to imaging spectroscopy data under the conditions of higher noise level and more complicating factors. This study evaluates the application of CWA to airborne imaging spectroscopy data for predicting diurnal and seasonal variation in canopy water content (CWC) for nut tree orchards. We collected CWC measurements and concurrent imagery from the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) instrument twice a day (morning and afternoon) in spring and fall of 2011 in California, USA. Several robust wavelet features were determined and compared to four water-sensitive spectral indices, three existing in the literature and one optimized in this study, for the assessment of predictive performance. Results showed that the best prediction using CWA (R2=0.84 and root mean square error (RMSE)=0.027kg/m2) was produced by a combination of three wavelet features and it was considerably better than those by the existing water indices. While the best wavelet feature (1100nm, scale 6) characterized the water absorption in the near-infrared region, the optimized index ND850,720 used a red edge band at 720nm instead of a direct water absorption band. A bootstrap sampling of the validation data set indicated that ND850,720 predicted CWC significantly worse (p<0.0001) and exhibited greater sensitivity to seasonality. Both CWA and ND850,720 revealed statistically significant diurnal declines of CWC in two different seasons in the context of a substantial seasonal decline, but the former detected greater declines in diurnal CWC. Our results demonstrated the feasibility of applying CWA to airborne imaging spectroscopy data for CWC mapping and its superiority to spectral indices for improved prediction of CWC and understanding of spectral-chemical relations. © 2013 Elsevier Inc. Source


Marquez-Calderon S.,Secretaria General de Salud Publica y Participacion | Ruiz-Ramos M.,Servicio de Informacion y Evaluacion | Juarez S.,Institute Economia
Revista Espanola de Salud Publica | Year: 2011

Background: Increasing trend and geographical variations in the use of caesarean section suggest the influence of non-cli nical factors. The objective was to describe the use of caesarean section in the Andalusian region in Spain by exploring the role of social, clinical, and health services variables. Methods: A cross-sectional study was carried out using vital statistics. It involves all births occurred in Andalusia during the period of 2007-2009. The dependent variable was the use of caesarean section and the set of covariates were classified into three groups: those with a clinical meaning, those related to the health services organization, and those with a social signifi cance. Multivariate logistic regressions were used. Results: In the data set of 293,558 births, the prevalence of caesarean delivery was 24.8%. The multivariate analysis high lights the labour complications as the clinical variable with the highest odds ratio (OR=19.36). Regarding the health services variables, the odds of experiencing a caesarean delivery were 55% higher on weekdays than on weekends. Cádiz was the pro vince with the highest OR for caesarean section (comparison between Cádiz and Almería: OR=1,21) where the ratio between births in public and private hospitals was 3.7. The frequency of caesarean section was 34% higher in women with third level education than those with no education. Conclusions: Labour complication is the most influential variable for caesarean section. Caesarean birth rate is above the accepted standards for all social classes and increases with edu cational level. Inter-provincial differences reflect different pat terns with regard to the use of private medicine. Source

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