ECOLOGÍA TRÓFICA DE AVES INSECTÍVORAS EN UN ÁREA NATURAL PROTEGIDA DE SAN LUIS POTOSÍ, MEXICO

In order to determine the hunting techniques, food substrates and segregation behaviors of bird life in the Biosphere Reserve Sierra del Abra-Tanchipa, San Luis Potosí, México, bird monitoring was performed during the summer of 2013, using the technique of intensive search with focal selection and assessing the information about hunting techniques and food substrates, through an analysis of simple correspondence and segregation behaviors, with conglomerate analysis. A total of 21 species, 18 genera and eight families were recorded, in addition to 42.6 % and 53.3 % of inertia in the hunting techniques and food layers, respectively. With regard to the segregation behaviors, the species with highest interaction in ecological niches was Icterus cucullatus (e=0.331) and those with the lowest participation were Tiaris olivaceus, Tharupis episcopus, Myarchus tuberculifer, Icterus galbula, Camptostoma imberbe (e=0.117). Frequency indexes showed greater use of the Branches and Collection technique. The analysis of behaviors and substrates did not indicate a significant difference between species with regard to their use (p-Value<0.001).Para determinar las técnicas de cacería, sustratos de alimentación y comportamientos de segregación por la avifauna de la Reserva de la Biosfera Sierra del Abra-Tanchipa, San Luis Potosí, México, se realizó un monitoreo de aves durante el verano del año 2013 con la técnica de búsqueda intensiva con selección focal. A la información sobre técnicas de cacería y sustratos de alimentación, se le aplicó un análisis de correspondencia simple, y a la de comportamientos de segregación, un análisis de conglomerados. Se registraron 21 especies, 18 géneros y ocho familias, además de 42.6% y 53.3% de inercia en las técnicas de cacería y sustratos de alimentación respectivamente. Respecto a los comportamientos de segregación, la especie con mayor interacción en los nichos ecológicos fue Icterus cucullatus (e=0.331) y las de menor participación fueron Tiaris olivaceus, Tharupis episcopus, Myarchus tuberculifer, Icterus galbula, Camptostoma imberbe (e=0.117). Los índices de frecuencia mostraron mayor utilización de las Ramas y técnica de Colecta. El análisis de los comportamientos y sustratos no indicaron diferencia significativa en las especies con relación a la utilización de éstos (p-Value<0.001)

MODELO ALTERNATIVO PARA DETERMINAR COEXISTENCIA Y SEGREGACIÓN TRÓFICA DE DOS FELINOS SIMPÁTRICOS: Puma concolor L. Y Panthera onca L.

A search was carried out, in databases, about feeding habits of Puma concolor and Panthera onca,considering the list of prey (mammals-birds) most often consumed, with the objective of applying the Game Theory (GT) and Nash Equilibrium in Pure Strategies (NEPS) as predictive models regarding the strategies of success and failure that allow establishing patterns of trophic coexistence-segregation between both sympatric felines, looking to generate recommendations for habitat management tomaintain viable populations of their prey and of both predators. Both models were run with data from Estrada (2008) on relative biomass consumed in kg species-1 for those species. The GT evidenced four Rational Dominant Predatory Strategies based on the consumption of C. paca (Tepe; 87.66, 12.53), N. narica (whitenosed coati; 46.01, 85.74), Pecari tajacu (wild boar; 6.02, 21.06), birds (39.27, 26.79). TheNEPS pointed to a Rational Predatory Strategy resulting through the consumption of N. Narica(white-nosed coati; 46.01, 85.74), respectively. It is concluded that the GT and NEPS turn out to be useful to identify patterns of trophic coexistence and segregation between these competitors, and the suggestion is to design habitat management-improvement which could allow viability, in this case, of N. narica (white-nosed coati) to maintain trophically stable populations of both predators.Se realizó una búsqueda, en bases de datos, sobre hábitos alimenticios de Puma concolor y Panthera onca, considerando la lista de presas (mamíferos-aves) más consumidas, con el objeto de aplicar la Teoría de Juegos (TJ) y el Equilibrio de Nash para Estrategias Puras (ENEP) como modelos predictivos sobre las estrategias de éxito y fracaso que permiten establecer patrones de coexistencia-segregación trófica entre ambos felinos simpátricos, con miras a generar recomendaciones de manejo de hábitat para mantener poblaciones viables de sus presas y de ambos depredadores. Ambos modelos fueron corridos con datos de Estrada (2008) sobre biomasa relativa consumida en kg especie-1 por dichas especies. La TJ evidenció cuatro Estrategias Racionales Depredatorias Dominantes basadas en el consumo de C. paca (Tepe; 87.66, 12.53), N. narica (Pizote; 46.01, 85.74), Pecari tajacu (Jabalí; 6.02, 21.06), Aves (39.27, 26.79). El ENEP señaló una Estrategia Racional Depredatoria resultante a través del consumo de N. narica (Pizote; 46.01, 85.74), respectivamente. Se concluye que la TJ y el ENEP resultan útiles para identificar patrones de coexistencia y segregación trófica entre estos competidores, y se sugiere diseñar establecer de manejo-mejoramiento de hábitat que permitan la viabilidad, en este caso, de N. narica (Pizote) para mantener poblaciones tróficamente estables de ambos predadores

ABUNDANCIA Y DENSIDAD DE ZORROS CHILLA (Pseudalopex griseus Gray, 1837) Y CULPEO (Pseudalopex culpaeus Molina, 1782) EN UNA FORMACIÓN XERÓFITA

During July-August, 2014, monitoring of Pseudalopex griseus and P. culpaeus foxes was performed through the registry of feces, to determine their abundance and population density in the Pan de Azúcar National Park, in Chañaral, Atacama, Chile. The frequency of observation (FO), index of relative abundance (IRA), and the differences between sampling sites were determined with Kruskal-Wallis. The distribution of the abundance was adjusted to a binomial model (BM), graphic differences in the abundance of cluster analysis (CA) and relative density with the estimator by the same name (IDR). The results show an average FO for the park of 23.1%, and an average IRA of 0.091 individuals ha-1; the Kruskal-Wallis analysis (p=0.0321) evidenced significant differences of the abundance between sites, the distribution of abundance was adjusted to a negative BM (p=0.330), the CA showed 13 Clusters with e=3.5, the average IDR was 0.43 individuals ha-1. Performing an adequate management and habitat improvement in the distribution zones is suggested, as well as regulating ecotourism in these zones during reproductive season and preventing feeding of the foxes by visitors.Durante julio-agosto, 2014 se realizó el monitoreo de zorros Pseudalopex griseus y P. culpaeus mediante el registro de heces, para determinar su abundancia y densidad poblacional en el Parque Nacional Pan de Azúcar, en Chañaral, Atacama, Chile. Se determinó la Frecuencia de observación (FO), índice de Abundancia Relativa (IAR) y se determinaron diferencias con Kruskal-Wallis entre sitios de muestreo. La distribución de la abundancia se ajustó a un Modelo Binomial (MB), las diferencias graficas en la abundancia con Análisis Clúster (AC) y la Densidad Relativa con el estimador del mismo nombre (IDR). Los resultados muestran una FO promedio para el parque de 23.1%, un IAR promedio de 0.091 individuos ha-1, el análisis Kruskal-Wallis (p=0.0321) evidenció diferencias significativas de la abundancia entre sitios, la distribución de la abundancia se ajustó a un MB negativo (p=0.330), el AC mostró 13 Clúster con un e=3.5, el IDR promedio fue de 0.43 individuos ha-1. Se sugiere realizar manejo adecuado y mejoramiento de hábitat en las zonas de distribución, regular el ecoturismo en esas zonas durante la época reproductiva y evitar alimentar a los zorros por los visitantes

DIVERSIDAD DE AVES EN EL CAMPUS CENTRAL DE LA UNIVERSIDAD AUTÓNOMA CHAPINGO, MÉXICO

From October to December of 2013, the bird life diversity in the venue of Universidad Autónoma Chapingo (UACh) was studied, using the method of belt transect to monitor birds. Of the species expected, 50 species were recorded and 63.8 % are known until today. The most represented Order was Passeriforme with 64 %. The wealth of species was analyzed according to the soil use of the university campus, such as urban, agricultural, livestock and forest conditions; no significant differences are shown (p-value=.0153). The distribution of abundance was adjusted to a log-normal (X2=16.1<18.3; gl=10), the Shannon diversity index was H’=3.1. The diversity of species estimated with the Shannon index did not show significant differences (p-value=0.0024) between conditions. The university campus offers the bird life various ecological niches that allow their coexistence under this type of conditions.De octubre a diciembre del 2013, se estudió la diversidad avifaunística en la sede de la Universidad Autónoma Chapingo (UACh), utilizando el método de transecto de faja para el monitoreo de aves. Se registraron 50 especies y se conocen hasta ahora 63.8% de las especies esperadas. El Orden más representado fue Passeriforme con 64%. La riqueza de especies analizada de acuerdo al uso de suelo del Campus Universitario, tales como, urbana, agrícola, pecuaria y forestal; no muestraron diferencias significativas (p-value=0.0153). La distribución de la abundancia se ajustó a una log-normal (X2=16.1<18.3; gl=10), el índice de diversidad de Shannon fue de H’=3.1. La diversidad de especies estimada con el índice de Shannon no exhibió diferencias significativas (p-value=0.0024) entre condiciones. El Campus Universitario ofrece a la avifauna diversos nichos ecológicos que permiten su coexistencia en este tipo de condiciones

Novel diterpenes with potent conidiation inducing activity

The isolation and structure determination of conidiogenol and conidiogenone, tetracyclic diterpenes with a novel carbon skeleton, from extracts of the fermentation broth of Penicillium cyclopium is reported. Conidiogenol and conidiogenone are potent and selective inducers of conidiogenesis in P. cyclopium in liquid culture, and relay information about the environmental conditions to the producing organism. (C) 2002 Elsevier Science Ltd. All rights reserved

The thermonuclear rate for the 19F(a,p)22Ne reaction at stellar temperatures

The $^{19}$F($\alpha$,p)$^{22}$Ne reaction is considered to be one of the main sources of fluorine depletion in AGB and Wolf-Rayet stars. The reaction rate still retains large uncertainties due to the lack of experimental studies available. In this work the yields for both exit channels to the ground state and first excited state of $^{22}$Ne have been measured and several previously unobserved resonances have been found in the energy range E$_{lab}$=792-1993 keV. The level parameters have been determined through a detailed R-matrix analysis of the reaction data and a new reaction rate is provided on the basis of the available experimental information.Comment: Accepted for publication in Phys Rev.

Nucleation and growth mechanism of polycarbazole deposited by electrochemistry

Polycarbazole (PCz) thin films have been deposited by electro-oxidation of carbazole in LiClO4 + anhydrous acetonitrile onto SnO2 coated glass substrates, by potentiostatic method and the nucleation and growth mechanism (NGM) were studied. The obtained current time transients (j-t) were fitted using a mathematical equation with three contributions: instantaneous nucleation with two-dimensional (IN2D) or three-dimensional (IN3D) growth, and also a progressive nucleation with three dimensional (PN3D) growth. At the beginning, the IN2D contribution is predominant but, quickly the IN3D processes become more important. At a deposition time t > 17 s the IN3D corresponds to 80 % of the total current. The visualization by scanning electron microscopy of the surface morphology of the PCz films is in agreement with the NGM proposed by the mathematical method. The film covers very rapidly the SnO2 under layer related to the 2D process, even if some heterogeneities randomly distributed in the films, issued from the 3D processes, are also visible. After two minutes of deposition, the roughness of the whole surface of the films corroborates the 3D processes domination. Therefore, the information directly obtained from the (j-t) transients is a suitable and very useful tool to predict the working conditions in order to control the type of morphology of the film prepared by electropolymerization

Experimental evidence of a natural parity state in 26^{26}Mg and its impact to the production of neutrons for the s process

We have studied natural parity states in $^{26}$Mg via the $^{22}$Ne($^{6}$Li,d)$^{26}$Mg reaction. Our method significantly improves the energy resolution of previous experiments and, as a result, we report the observation of a natural parity state in $^{26}$Mg. Possible spin-parity assignments are suggested on the basis of published $\gamma$-ray decay experiments. The stellar rate of the $^{22}$Ne($\alpha$,$\gamma$)$^{26}$Mg reaction is reduced and may give rise to an increase in the production of s-process neutrons via the $^{22}$Ne($\alpha$,n)$^{25}$Mg reaction.Comment: Published in PR