Stable isotopes reveal differences in diet among reed bunting subspecies that vary in bill size

Reed bunting Emberiza schoeniclus subspecies vary considerably in bill size and shape and seem to be at an early stage of speciation, in which bill might be indirectly causing reproductive isolation. Hence, we evaluated whether bill size, as well as age and sex, are associated with foraging niche in three west European subspecies of reed bunting: the thin-billed schoeniclus, the intermediate-billed lusitanica and the thick-billed witherbyi. Blood sampling was undertaken at three sites in southwest Europe during the winter (when these subspecies co-occur), and stable isotope analyses (carbon and nitrogen) were performed to assess their foraging niches. Stable isotope analyses of potential food items confirmed uniform baseline isotopic composition among sites. schoeniclus showed a significantly broader isotopic niche than lusitanica and witherbyi, which seemed otherwise similar despite the fact that witherbyi is more divergent in bill traits. Stable isotope ratios were consistent with the latter two subspecies feeding on C3-plant-feeding insects, whereas schoeniclus diet also included C4 plant material. Despite its lower sexual dimorphism, sex and age differences were found only in schoeniclus, but these differences vary between locations in a complex manner. Our results suggest that bill size and shape differentiated between northern, migratory and southern, resident subspecies as a consequence of natural selection through competition during the winter, which is now reflected in isotopic niche divergence between subspecies. The potential roles of sexual selection, reed thickness and summer temperature on the difference in bill size (and greater sexual dimorphism) between lusitanica and witherbyi are discussed

Habilidades Sociales y Rendimiento Académico en Estudiantes de la Universidad Cesar Vallejo, Sede Callao 2,018.

Esta investigación enfatiza la relación de la variable habilidades sociales que representa el nuevo concepto a desarrollar en el sector educación y la variable rendimiento académico que es la medición respectiva del desarrollo del curriculum que asume hoy en día toda organización y todo individuo que convive en una sociedad. Este estudio formulo como objetivo de investigación: Determinar la relación que existe entre las Habilidades Sociales y el Rendimiento Académico en los estudiantes de la Universidad Cesar Vallejo , Sede Callao, Lima 2018. Este estudio es de tipo básico y de diseño no experimental, transversal y correlacional. Se utilizó la secuencia del método hipotético deductivo y conto con una población de 60 alumnos a los cuales se les aplico dos cuestionarios de 15 item cada uno y que fueron sometidos a juicio de expertos para la validez y al estadístico de Alfa de Crombach para la fiabilidad cuyos resultados fueron de 0,833 para el cuestionario de habilidades sociales y 0,817 para el cuestionario de rendimiento académico. Luego de procesar los datos y someterlo al estadístico de Rho de Spearman se evidencio una correlación moderada positiva de 0,513 y un P valor de 0,000 con lo que se concluyó que existe una relación inversa entre las habilidades sociales y el rendimiento académico en estudiantes de la Universidad Cesar Vallejo. Sede Callao, 2018

Impersonalidad y responsabilidad colectiva en las instituciones públicas

Los autores reflexionan sobre un conjunto de fenómenos y problemáticas ligadas al ejercicio de las tareas de los funcionarios públicos al interior de la arena institucional-estatal, y problematizan lo que denominan la “impersonalidad” de las tareas de los agentes estatales y la responsabilidad colectiva que implica.Facultad de Humanidades y Ciencias de la Educació

Modelling spatially sampled proportion processes​​

Many ecological processes are measured as proportions and are spatially sampled. In all these cases the standard procedure has long been the transformation of proportional data with the arcsine square root or logit transformation, without considering the spatial correlation in any way. This paper presents a robust regression model to analyse this kind of data using a beta regression and including a spatially correlated term within the Bayesian framework. As a practical example, we apply the proposed approach to a spatio-temporally sampled fishery discard dataset

Multivalued synchronization by Poincar coupling

"This work presents multivalued chaotic synchronization via coupling based on the Poincaré plane. The coupling is carried out by an underdamped signal, triggered every crossing event of the trajectory of the master system through a previously defined Poincaré plane. A master–slave system is explored, and the synchronization between the systems is detected via the auxiliary system approach and the maximum conditional Lyapunov exponent. Due to the response to specific conditions two phenomena may be obtained: univalued and multivalued synchronization. Since the Lyapunov exponent is not enough to detect these two phenomena, the distance between the pieces of trajectories of the slave and auxiliary systems with different initial conditions is also used as a tool for the detection of multivalued synchronization. Computer simulations using the benchmark chaotic systems of Lorenz and Rössler are used to exemplify the approach proposed.

A New Optimization Strategy for Solving the Fall-Off Boundary Value Problem in Pixel-Value Di®erencing Steganography

In Digital Image Steganography, Pixel-Value Di®erencing (PVD) methods use the di®erence between neighboring pixel values to determine the amount of data bits to be inserted. The main advantage of these methods is the size of input data that an image can hold. However, the fall- o® boundary problem and the fall in error problem are persistent in many PVD steganographic methods. This results in an incorrect output image. To ¯x these issues, usually the pixel values are either somehow adjusted or simply not considered to carry part of the input data. In this paper, we enhance the Tri-way Pixel-Value Di®erencing method by ¯nding an optimal pixel value for each pixel pair such that it carries the maximum input data possible without ignoring any pair and without yielding incorrect pixel values

Polyploidy Expands the Range of Centaurium (Gentianaceae)

The Mediterranean region is one of the most important worldwide hotspots in terms of number of species and endemism, and multiple hypotheses have been proposed to explain how diversification occurred in this area. The contribution of different traits to the diversification process has been evaluated in different groups of plants. In the case of Centaurium (Gentianaceae), a genus with a center of diversity placed in the Mediterranean region, polyploidy seems to have been an important driver of diversification as more than half of species are polyploids

Isolation and Characterization of Microsatellites Markers in Centaurium Grandiflorum ssp. Boissieri

Background: Estimating outcrossing/selfing rates and characterizing genetic diversity with microsatellite markers are crucial to understanding the evolution of plant mating systems. Methods and results: We developed, optimized and characterized eight new primer pairs for Centaurium grandiflorum ssp. boissieri and transferred them to three subspecies of Centaurium quadrifolium. Two SSR loci were transferred from Sabatia campestris to the four Centaurium taxa. Polymorphisms, He, Ho and H–W deviations were estimated in two populations of C. grandiflorum ssp. boissieri and in seven individuals each of C. quadrifolium ssp. barrelieri, C. quadrifolium ssp. parviflorum and C. quadrifolium ssp. quadrifolium. A total of 80 individuals was used in these experiments. The number of polymorphic loci varied among species from one to ten. A total of 127 alleles was scored. The average number of alleles per locus was 12.7. He was higher than Ho in all sampled populations. Hardy–Weinberg equilibrium was found for some loci in different species. Conclusions: This is the first report of microsatellites successfully amplified in the whole Centaurium genus. They will be valuable for estimating mating system parameters and genetic diversity and exploring their relationships with the wide variation in flower morphology in the genus, especially anther-stigma separation.Consejo Nacional de Ciencia y Tecnología #252042Ministerio de Economia, Industria y Competitividad CGL2013-45037-PMinisterio de Ciencia e Innovación PGC2018-099608-B-10