4,255 research outputs found

    Evaluación del Efecto de Dos Bioestimulantes sobre el Rendimiento de Dos Variedades de Quinua ( Chenopodium quínoa Wild) en la localidad de Mocupe - Lambayeque

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    El presente trabajo de investigación se realizó en la localidad de Mocupe, Distrito de Lagunas, Provincia de Chiclayo, del departamento de Lambayeque; de propiedad del Ing. Jhon Rojas Barboza, ubicada a 33 msnm, en las coordenadas geográficas 6º 59’ 25” de Latitud Sur y 79º 37’ 18’’ de Longitud Oeste, con el objetivo de determinar el efecto de dos bioestimulantes sobre el rendimiento de dos variedades de quinua (Chenopodium quínoa Willd). Los tratamientos fueron 14 formados por las variedades de quinua Salcedo INIA y Pasankalla INIA 415, con aplicación de bioestimulantes Ergostin y Agrostemin en dosis de 0.40, 0.80 y 1.20 l/ha; además se incluyó dos testigos que fueron las dos variedades sin aplicación. El diseño que se utilizó fue el de Bloques Completos al Azar con arreglo factorial (2x2x3+2). Los datos evaluados fueron: Rendimiento en grano, longitud de panoja, diámetro de panoja, peso de granos/planta, peso de 1000 granos, altura de planta a los 30, 60, 76 y 93 días, número de hojas a los 30, 60, 76 y 93 días, ancho de hojas a los 30, 60, 76 y 93 días, longitud de hojas a los 30, 60, 76 y 93 días y diámetro de tallo a los 30, 60, 76 y 93 días. Según los resultados se determino que Salcedo con aplicación de Agrostemin en dosis de 1.20 l/ha respondió positivamente al comportamiento agronómico, obteniendo un mayor rendimiento. Para longitud de panoja, ambas variedades, respondieron mejor a la aplicación de Ergostin en dosis de 1.20 litros/ha. Pero, para diámetro de panoja, Pasankalla, respondió mejor a Agrostemin en dosis de 0.80 litros/ha. En cambio, para peso de granos por planta y peso de 1000 granos, Salcedo respondió mejor a Agrostemin en dosis de 1.20 litros/ha. Para altura de planta a los 30, 60, 76 y 93 días, las mayores alturas de Salcedo y Pasankalla se atribuyen al crecimiento alcanzado con dosis medias (0.80 l/ha) a altas (1.20 l/ha) de los bioestimulantes aplicados. Para número, ancho y longitud de hojas a los 30, 60, 76 y 93 días, se observa una mayor respuesta a dosis medias a altas y a factores genéticos de las variedades. Para diámetro de tallo a los 30, 60, 76 y 93 días, Salcedo respondió mejor a la aplicación de dosis altas (1.20 l/ha). Desde el punto de vista económico y de rentabilidad se observa que en todos los tratamientos existe rentabilidad positiva, destacando el tratamiento Salcedo-Ergostin-0.80 l/ha con un beneficio de S/14,395.00

    Site Fidelity in Space Use by Spider Monkeys (Ateles geoffroyi) in the Yucatan Peninsula, Mexico

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    Animal home ranges may vary little in their size and location in the short term but nevertheless show more variability in the long term. We evaluated the degree of site fidelity of two groups of spider monkeys (Ateles geoffroyi) over a 10- and 13-year period, respectively, in the northeastern Yucatan peninsula, Mexico. We used the Local Convex Hull method to estimate yearly home ranges and core areas (defined as the 60% probability contour) for the two groups. Home ranges varied from 7.7 to 49.6 ha and core areas varied from 3.1 to 9.2 ha. We evaluated the degree of site fidelity by quantifying the number of years in which different areas were used as either home ranges or core areas. Large tracts were used only as home ranges and only for a few years, whereas small areas were used as either core area or home range for the duration of the study. The sum of the yearly core areas coincided partially with the yearly home ranges, indicating that home ranges contain areas used intermittently. Home ranges, and especially core areas, contained a higher proportion of mature forest than the larger study site as a whole. Across years and only in one group, the size of core areas was positively correlated with the proportion of adult males in the group, while the size of home ranges was positively correlated with both the proportion of males and the number of tree species included in the diet. Our findings suggest that spider monkey home ranges are the result of a combination of long-term site fidelity and year-to-year use variation to enable exploration of new resources

    Quantifying uncertainty due to fission-fusion dynamics as a component of social complexity.

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    Groups of animals (including humans) may show flexible grouping patterns, in which temporary aggregations or subgroups come together and split, changing composition over short temporal scales, (i.e. fission and fusion). A high degree of fission-fusion dynamics may constrain the regulation of social relationships, introducing uncertainty in interactions between group members. Here we use Shannon's entropy to quantify the predictability of subgroup composition for three species known to differ in the way their subgroups come together and split over time: spider monkeys (Ateles geoffroyi), chimpanzees (Pan troglodytes) and geladas (Theropithecus gelada). We formulate a random expectation of entropy that considers subgroup size variation and sample size, against which the observed entropy in subgroup composition can be compared. Using the theory of set partitioning, we also develop a method to estimate the number of subgroups that the group is likely to be divided into, based on the composition and size of single focal subgroups. Our results indicate that Shannon's entropy and the estimated number of subgroups present at a given time provide quantitative metrics of uncertainty in the social environment (within which social relationships must be regulated) for groups with different degrees of fission-fusion dynamics. These metrics also represent an indirect quantification of the cognitive challenges posed by socially dynamic environments. Overall, our novel methodological approach provides new insight for understanding the evolution of social complexity and the mechanisms to cope with the uncertainty that results from fission-fusion dynamics

    Sexual selection on male vocal fundamental frequency in humans and other anthropoids

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    D.A.P. was supported by a National Institutes of Mental Health T32 MH70343-05 fellowship. J.R.W. was supported by a National Science Foundation predoctoral fellowship.In many primates, including humans, the vocalizations of males and females differ dramatically, with male vocalizations and vocal anatomy often seeming to exaggerate apparent body size. These traits may be favoured by sexual selection because low-frequency male vocalizations intimidate rivals and/or attract females, but this hypothesis has not been systematically tested across primates, nor is it clear why competitors and potential mates should attend to vocalization frequencies. Here we show across anthropoids that sexual dimorphism in fundamental frequency (F0) increased during evolutionary transitions towards polygyny, and decreased during transitions towards monogamy. Surprisingly, humans exhibit greater F0 sexual dimorphism than any other ape. We also show that low-F0 vocalizations predict perceptions of men’s dominance and attractiveness, and predict hormone profiles (low cortisol and high testosterone) related to immune function. These results suggest that low male F0 signals condition to competitors and mates, and evolved in male anthropoids in response to the intensity of mating competition.PostprintPeer reviewe

    Psychometric properties of the Alcohol Use Disorders Identification Test (AUDIT) across cross-cultural subgroups, genders, and sexual orientations: Findings from the International Sex Survey (ISS)

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    © 2023 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/bync-nd/4.0/).INTRODUCTION: Despite being a widely used screening questionnaire, there is no consensus on the most appropriate measurement model for the Alcohol Use Disorders Identification Test (AUDIT). Furthermore, there have been limited studies on its measurement invariance across cross-cultural subgroups, genders, and sexual orientations. AIMS: The present study aimed to examine the fit of different measurement models for the AUDIT and its measurement invariance across a wide range of subgroups by country, language, gender, and sexual orientation. METHODS: Responses concerning past-year alcohol use from the participants of the cross-sectional International Sex Survey were considered (N = 62,943; M age: 32.73; SD = 12.59). Confirmatory factor analysis, as well as measurement invariance tests were performed for 21 countries, 14 languages, three genders, and four sexual-orientation subgroups that met the minimum sample size requirement for inclusion in these analyses. RESULTS: A two-factor model with factors describing 'alcohol use' (items 1-3) and 'alcohol problems' (items 4-10) showed the best model fit across countries, languages, genders, and sexual orientations. For the former two, scalar and latent mean levels of invariance were reached considering different criteria. For gender and sexual orientation, a latent mean level of invariance was reached. CONCLUSIONS: In line with the two-factor model, the calculation of separate alcohol-use and alcohol-problem scores is recommended when using the AUDIT. The high levels of measurement invariance achieved for the AUDIT support its use in cross-cultural research, capable also of meaningful comparisons among genders and sexual orientations.Peer reviewe

    Bose-Einstein correlations of same-sign charged pions in the forward region in pp collisions at √s=7 TeV

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    Bose-Einstein correlations of same-sign charged pions, produced in protonproton collisions at a 7 TeV centre-of-mass energy, are studied using a data sample collected by the LHCb experiment. The signature for Bose-Einstein correlations is observed in the form of an enhancement of pairs of like-sign charged pions with small four-momentum difference squared. The charged-particle multiplicity dependence of the Bose-Einstein correlation parameters describing the correlation strength and the size of the emitting source is investigated, determining both the correlation radius and the chaoticity parameter. The measured correlation radius is found to increase as a function of increasing charged-particle multiplicity, while the chaoticity parameter is seen to decreas

    Observation of an Excited Bc+ State

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    Using pp collision data corresponding to an integrated luminosity of 8.5 fb-1 recorded by the LHCb experiment at center-of-mass energies of s=7, 8, and 13 TeV, the observation of an excited Bc+ state in the Bc+π+π- invariant-mass spectrum is reported. The observed peak has a mass of 6841.2±0.6(stat)±0.1(syst)±0.8(Bc+) MeV/c2, where the last uncertainty is due to the limited knowledge of the Bc+ mass. It is consistent with expectations of the Bc∗(2S31)+ state reconstructed without the low-energy photon from the Bc∗(1S31)+→Bc+γ decay following Bc∗(2S31)+→Bc∗(1S31)+π+π-. A second state is seen with a global (local) statistical significance of 2.2σ (3.2σ) and a mass of 6872.1±1.3(stat)±0.1(syst)±0.8(Bc+) MeV/c2, and is consistent with the Bc(2S10)+ state. These mass measurements are the most precise to date
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