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Lack of evidence for the presence of macaws of the Anodorhynchus genus in the Colombian-Brazilian river basin of the Vaupés
López-Lanús,Bernabé; Laverde,Oscar; Omena Jr.,Reynier; Olarte,Luis G.;
El hornero , 2009,
Abstract: it is generally understood that the anodorhynchus genus of macaws does not spread north of the amazon river. however, recent published information suggests that the endangered hyacinth macaw anodorhynchus hyacinthinus may occur in the region of the papurí river, lower vaupés, in amazonian colombia. this information is hypothetical, based on old reports and observations with imprecise geographical data. our objective was to confirm the presence of macaws of the genus anodorhynchus in the lower vaupés, colombia, and in nearby negro river, brazil. we carried out fieldwork and interviews from september 2004 to july 2005, but we failed to locate the species. notwithstanding, we received information from 8% of the interviewed members of local ethnic groups suggesting that a macaw with similar characteristics to anodorhynchus genus could inhabit this area. we discuss about the presence of macaws of this genus north of the amazon river, and their potential food sources (local palms). on the basis of the absence of recordings we conclude that anodorhynchus hyacinthinus should be considered hypothetical, at least in colombia. nevertheless, we recommend following the precautionary principle and suggest further work in the area.
The infrared and raman spectra of tetrachlorophosphonium (V) oxotetrachlorovanadate (V), PCL4VOCL4. An experimental and theoretical study
Roldán,M. L.; Lanús,H.; Brandán,S. A.; López,J. J.; Varetti,E. L.; Ben Altabef,A.;
Anales de la Asociaci?3n Qu?-mica Argentina , 2004,
Abstract: infrared and raman spectra were obtained for tetrachlorophosphonium (v) oxotetrachlorovanadate (v), pcl4vocl4, and a complementary quantum chemistry theoretical study was made for both ions. the molecular structures of the pcl4+ and vocl4- ionswere optimised by means of ab-initio and density functional theory, using different basis sets. such structures present the expected td symmetry for pcl4+ and c4ν symmetry for vocl4-. the wavenumbers corresponding to the normal modes of vibration were calculated and used to confirm the spectral band assignments. the harmonic force constants given by theory were scaled to reproduce adequately the experimental wavenumbers.
Sesto, Carmen. 2005. La vanguardia ganadera bonaerense, 1856-1990. Tomo II: "Historia del capitalismo agrario pampeano". Buenos Aires: UB; Siglo XXI
Andrés López
Mundo agrario , 2006,
Abstract:
Maestros de la medicina interna chilena Masters of Internal Medicine, in Chile
Gloria López S
Revista médica de Chile , 2011,
Abstract:
Formación en planificación para la pluralidad
JESúS LóPEZ
Cuadernos del Cendes , 2006,
Abstract:
Sedation/analgesia guidelines for endoscopy Directrices "guidelines" de sedación/analgesia en endoscopia
L. López Rosés
Revista Espa?ola de Enfermedades Digestivas , 2006,
Abstract:
Photoluminescence and Structural Properties of ZnO Nanorods Growth by Assisted-Hydrothermal Method  [PDF]
S. López-Romero, M. García-H
World Journal of Condensed Matter Physics (WJCMP) , 2013, DOI: 10.4236/wjcmp.2013.33024
Abstract:

Semiconducting zinc oxide (ZnO) nanorods were obtained in bulk quantity by an hexamethylenetetramine (HMTA)-assisted hydrothermal method at low temperature (90°C) with methenamine ((CH3)6N4 as surfactant and catalyst and zinc nitrate Zn(NO3)2·6H2O as Zn source. The structure and phase of ZnO nanorods were studied using x-ray diffraction (XRD) and high resolution transmission electron microscopy techniques (HRTEM). The morphology of the nanostructures was studied by scanning electron microscope (SEM) method. The photoluminescence (PL) properties were investigated founding two emission bands under UV excitation.

Geometric Study of the Weak Equilibrium in a Weighted Case for a Two-Dimensional Competition Game  [PDF]
López M. Dolores, Rodrigo Javier, Sánchez José Manuel
American Journal of Operations Research (AJOR) , 2013, DOI: 10.4236/ajor.2013.33030
Abstract:

In this work, an improvement of the results presented by [1] Abellanas et al. (Weak Equilibrium in a Spatial Model. International Journal of Game Theory, 40(3), 449-459) is discussed. Concretely, this paper investigates an abstract game of competition between two players that want to earn the maximum number of points from a finite set of points in the plane. It is assumed that the distribution of these points is not uniform, so an appropriate weight to each position is assigned. A definition of equilibrium which is weaker than the classical one is included in order to avoid the uniqueness of the equilibrium position typical of the Nash equilibrium in these kinds of games. The existence of this approximated equilibrium in the game is analyzed by means of computational geometry techniques.

Monodisperse ZnO Solid Spheres by an Assisted Structure Directing Agent-Hydrothermal Method  [PDF]
S. López-Romero, M. J. Quiroz Jiménez
World Journal of Condensed Matter Physics (WJCMP) , 2015, DOI: 10.4236/wjcmp.2015.54033
Abstract: Monodisperse ZnO solid spheres nanostructures were synthesized and deposited on Si (100) silicon substrates by the hexamethylenetetramine (HMTA)-assisted hydrothermal method at high temperature (200°C). In this case the HMTA is used as structure directing agent (SDA) to growth of the ZnO solid spheres. The source material used was zinc nitrate hexahydrate under a chemical reaction of hydrolysis-condensation of the Zn2+ salt aqueous solution. The structure and morphology of the ZnO solid spheres were studied by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Furthermore, the photoluminescence (PL) of the ZnO solid spheres was measured to optical characterization of the product. The remarkable influence of the HMTA as structure directing agent and the reaction temperature to the formation of the solid spheres nanostructures is demonstrated.
Increasing Water Use Efficiency in Husk Tomato (Physalis ixocarpa Brot) Production in Tabasco, Mexico with Improved Irrigation Water Management  [PDF]
Rutilo López-López, Ignacio Sánchez Cohen, Marco Antonio InzunzaIbarra, Andrés Fierro álvarez, Gerardo Esquivel Arriaga
Journal of Water Resource and Protection (JWARP) , 2014, DOI: 10.4236/jwarp.2014.613114
Abstract: Husk tomato production technology was developed utilizing plastic sheeting and drip irrigation based on the results of reference evapotranspiration and crop coefficients (Kc) proposed at different phenological stages. The objectives of this study were as follows: 1) to evaluate the effect of plastic sheeting on the yield of husk tomato fruit with drip irrigation based on crop evapotranspiration; 2) to validate the use of drip irrigation technology and plastic sheeting in husk tomato production using demonstration plots; and 3) to determine the profitability and economic viability of the product in the domestic market. The proposed Kc values were 0.25, 0.71 and 0.56 in the initial, intermediate and final stage of crop development, respectively. Irrigation rates ranged from 2.5 to 6 mm·day-1, which was equivalent to an irrigation time of 0.6 to 2.5 hr. Soil moisture tension was monitored with tensiometers at depths of 15 and 30 cm in a loamy eutricfluvisol. The use of plastic sheeting increased husk tomato yield by 56.2% and water productivity by 63.5% under drip irrigation conditions when basing irrigation levels on crop evapotranspiration. Soil matrix potential varied between depths of 15 and 30 cm based on irrigation or rainfall amounts and the use of plastic sheeting with values being higher when the plastic sheeting was used. The husk tomato fruit yield in validation plots was 46 and 54.6 t·ha-1 with water use efficiencies ranging from 16.1 to 19.1 kg·m-3. These results exceeded the national average of 14 t·ha-1 and water use efficiency of 2.54 kg·m-3. With this new technology, a cost benefit ratio of 3.6 is obtained, which represents an economically profitable margin for farmers in the region.
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