Eigenvalues of laplacian matrices of the cycles with one negative-weighted edge

We study the individual behavior of the eigenvalues of the laplacian matrices of the cyclic graph of order $n$, where one edge has weight $\alpha\in\mathbb{C}$, with $\operatorname{Re}(\alpha)<0$, and all the others have weights $1$. This paper is a sequel of a previous one where we considered $\operatorname{Re}(\alpha) \in[0,1]$ (Eigenvalues of laplacian matrices of the cycles with one weighted edge, Linear Algebra Appl. 653, 2022, 86--115). We prove that for $\operatorname{Re}(\alpha)<0$ and $n>\operatorname{Re}(\alpha-1)/\operatorname{Re}(\alpha)$, one eigenvalue is negative while the others belong to $[0,4]$ and are distributed as the function $x\mapsto 4\sin^2(x/2)$. Additionally, we prove that as $n$ tends to $\infty$, the outlier eigenvalue converges exponentially to $4\operatorname{Re}(\alpha)^2/(2\operatorname{Re}(\alpha)-1)$. We give exact formulas for the half of the inner eigenvalues, while for the others we justify the convergence of Newton's method and fixed-point iteration method. We find asymptotic expansions, as $n$ tends to $\infty$, both for the eigenvalues belonging to $[0,4]$ and the outlier. We also compute the eigenvectors and their norms.Comment: 28 pages, 8 figure

Influence of Teaching Style on Physical Education Adolescents’ Motivation and Health-Related Lifestyle

According to various WHO reports in 2018, a large number of adolescents worldwide are either overweight or obese. This situation is the result of not following a healthy and balanced diet, combined with a lack of practice of physical activity. In this sense, Physical Education classes could help to solve the problem. The present study seeks to analyze the relationship between the role of the teacher in relation to the structural dimensions of the PE teaching environment and the basic psychological needs and self-motivation of adolescents as determinants of their behaviors related to eating habits and the practice of physical activity. A total of 1127 secondary school adolescents between the ages of 13 and 18 participated in this study. Questionnaires were used: Perceived Autonomy Support Scale, Psychologically Controlling Teaching Scale, Basic Psychological Needs in Physical Education, Frustration of Psychological Needs in PE context, Physical Activity Class Satisfaction Questionnaire, Perceived Locus of Causality Revised, and WHO’s Global school-based student health survey. A structural equations model was elaborated to explain the causal relationships between the variables. The results showed that autonomy support positively predicted the three structural dimensions of PE classes, while, in contrast, they were negatively predicted by psychological control. The three structural dimensions positively predicted the satisfaction of psychological needs and negatively predicted the thwarting of psychological needs. Self-determined motivation was positively predicted by the satisfaction of psychological needs and negatively predicted by the thwarting of psychological needs. Finally, self-determined motivation positively predicted healthy eating habits and the practice of physical activity and negatively predicted unhealthy eating habits. Certainly, the results obtained in this study support the postulates of the self-determination theory, demonstrating the predictability of PE class context towards the adoption of healthy lifestyle habits, such as a proper diet and the regular practice of physical activity

Effects of Replacing Dry-rolled Corn with Increasing Levels of Corn Dried Distillers Grains with Solubles on Characteristics of Digestion, Microbial Protein Synthesis and Digestible Energy of Diet in Hair Lambs Fed High-concentrate Diets.

Four male lambs (Katahdin; average live weight 25.9±2.9 kg) with "T" type cannulas in the rumen and proximal duodenum were used in a 4×4 Latin square experiment to evaluate the influence of supplemental dry distillers grain with solubles (DDGS) levels (0, 10, 20 and 30%, dry matter basis) in substitution for dry-rolled (DR) corn on characteristics of digestive function and digestible energy (DE) of diet. Treatments did not influence ruminal pH. Substitution of DR corn with DDGS increased ruminal neutral detergent fiber (NDF) digestion (quadratic effect, p&lt;0.01), but decreased ruminal organic matter (OM) digestion (linear effect, p&lt;0.01). Replacing corn with DDGS increased (linear, p≤0.02) duodenal flow of lipids, NDF and feed N. But there were no treatment effects on flow to the small intestine of microbial nitrogen (MN) or microbial N efficiency. The estimated UIP value of DDGS was 44%. Postruminal digestion of OM, starch, lipids and nitrogen (N) were not affected by treatments. Total tract digestion of N increased (linear, p = 0.04) as the DDGS level increased, but DDGS substitution tended to decrease total tract digestion of OM (p = 0.06) and digestion of gross energy (p = 0.08). However, it did not affect the dietary digestible energy (DE, MJ/kg), reflecting the greater gross energy content of DDGS versus DR corn in the replacements. The comparative DE value of DDGS may be considered similar to the DE value of the DR corn it replaced up to 30% in the finishing diets fed to lambs

Physical Education Classes as a Precursor to the Mediterranean Diet and the Practice of Physical Activity

Physical activity and a healthy, balanced diet are remaining unresolved issues among young people. According to the World Health Organization, young people do not get enough exercise during the week, and physical education classes are the best way to promote healthy habits. This study aims to analyze how the role of the teacher influences the frustration of psychological needs, coping strategies, motivation, and the adoption of healthy eating habits through the Mediterranean diet and the regular practice of physical activity. The study involved 1031 boys and 910 girls between the ages of 13 and 18. To explain the relationships between the different variables included in this study, a model of structural equations has been developed. The results showed that autonomy support negatively predicted the frustration of four psychological needs. The failure to meet four psychological needs negatively predicted resilience. Likewise, resilience positively predicted autonomous motivation, and this positively predicted the Mediterranean diet and the practice of physical activity. Thus, the results obtained in the present study are in line with those of various studies wherein physical education classes were seen to help consolidate healthy living habits

Analysis of the Graphic Industry in the Context of the Manufacturing Spanish Sector

Texto dispoñible en galego e españolNeste traballo descríbense brevemente os principais fitos tecnolóxicos que foron marcando e configurando o sector gráfico, e abórdase a súa delimitación. Así mesmo, lévase a cabo unha análise comparativa co sector manufactureiro español, estudando o comportamento de ambos os dous sectores nos ámbitos da atomización e da dispersión empresarial, dos investimentos realizados, das subvencións recibidas, da capacidade de xeración de emprego e da demografía. Finalmente, tamén se aborda a singularidade que o sector gráfico español representa no ámbito do comercio exterior, e algúns dos retos que as actuais forzas globalizadoras da economía lle formulanEn este trabajo se describen brevemente los principales hitos tecnológicos que han ido marcando y configurando el sector gráfico, y se aborda su delimitación. Asimismo, se lleva a cabo un análisis comparativo con el sector manufacturero español, estudiando el comportamiento de ambos sectores en los ámbitos de atomización y dispersión empresarial, inversiones realizadas, subvenciones recibidas, capacidad de generación de empleo y demografía. Finalmente, también se aborda la singularidad que el sector gráfico español representa en el ámbito del comercio exterior, y algunos de los retos que las actuales fuerzas globalizadoras de la economía le planteanIn this paper, main technological milestones which have marked and formed the graphical sector are described, and its delimitations is approached. Likewise, a comparative analysis with the Spanish manufacturing sector is carried out to study the behaviour of both sectors with regard to the managerial atomization and dispersion, investments, received subsidies, employment creation capacity, and demography. Finally, both the Spanish graphical sector singularity in the foreign trade and some of the challenges current economy global forces exert on it also are approachedS

Sperm whale echolocation behaviour reveals a directed, prior-based search strategy informed by prey distribution

The fieldwork was funded by a grant from the Carlsberg Foundation to B. Møhl and ONR, SERDP and FNU grants to MJ, PJOM and PTM. PJOM was supported by a Royal Society Fellowship, NAS by the International Campus of Excellence of the Canary Islands, MJ by the Marine Alliance for Science and Technology for Scotland and AF partly by project CETOBAPH (grant number CGL2009-1311218).Predators make foraging decisions based upon sensory information about resource availability, but little is known about how large, air-breathing predators collect and use such information to maximize energy returns when foraging in the deep sea. Here, we used archival tags to study how echolocating sperm whales (Physeter macrocephalus) use their long-range sensory capabilities to guide foraging in a deep-water habitat consisting of multiple, depth-segregated prey layers. Sperm whales employ a directed search behaviour by modulating their overall sonar sampling with the intention to exploit a particular prey layer. They forage opportunistically during some descents while actively adjusting their acoustic gaze to sequentially track different prey layers. While foraging within patches, sperm whales adjust their clicking rate both to search new water volumes as they turn and to match the prey distribution. This strategy increases information flow and suggests that sperm whales can perform auditory stream segregation of multiple targets when echolocating. Such flexibility in sampling tactics in concert with long-range sensing capabilities apparently allow sperm whales to efficiently locate and access prey resources in vast, heterogeneous, deep water habitats.PostprintPeer reviewe

English Language Teaching Approaches: A Comparison of the Grammar-translation, Audiolingual, Communicative, and Natural Approaches

This work compares four of the most widely used teaching approaches in foreign language contexts; Grammar-Translation, Audiolingual, Communicative, and Natural Approaches. For the comparison, seven features were considered; supporting theories, creation purpose, materials and techniques used, and the roles of teachers, students, and students´ mother tongue in the teaching-learning process. A checklist was created to provide a visual representation of the characterization of the features compared in each approach. Several texts and articles were reviewed to be accurate in the characterization of the information. The results show that the characteristics of each approach were determined for the epoch in which they were proposed and promoted. Some characteristics such as the use of books overlapped all approaches compared in this work; others were unique to certain approaches, supporting theories, for instance; and, others were common in two or three approaches, as in the case of the use of conversations and the role of learners as active learners, to cite some examples

Análisis espacial de terrenos afectados por minería de suelos en un área del partido de La Plata a partir de índices de vegetación

La actividad extractiva vinculada a la minería de suelos data desde hace más de 100 años en diversos Partidos dentro de la Provincia de Buenos Aires. En el Partido de La Plata, esta actividad ha implicado la pérdida del “capital natural”, en las áreas/cuencas de producción destinadas al abastecimiento de alimentos a los centros urbanos más próximos. Poder cuantificar las áreas degradadas por esta actividad en los entornos de la Ciudad de La Plata y de las grandes ciudades de la Provincia de Buenos Aires contribuiría a la valoración de la problemática, coadyuvando al diseño de estrategias para la protección del recurso y la remediación de los pasivos ambientales generados. A partir de esta situación se cree oportuno poder desarrollar una metodología que permita la identificación, evaluación y valoración de estas áreas degradadas. Las técnicas de análisis espacial y teledetección, en este caso, permiten tener acceso al conocimiento de las situaciones y estado en el que se encuentran las coberturas desde un punto de vista espectral, pudiéndose delimitar de manera preliminar los terrenos que presenten signos de haber sido removido su horizonte superficial, ya sea agentes erosivos naturales o por actividad minera (Fraziers et al., 1989; De Vliegher, 1990; Dubocq et al., 1991). El presente trabajo tiene como objetivo confeccionar Índices de Vegetación (SAVI y NDVI) para 2 momentos del año contrastantes entre sí (otoño – primavera) en un área piloto del Partido de La Plata, con el fin de determinar cubiertas correspondientes a suelos afectados por minería (Suelos Decapitados). A su vez se pretende obtener un valor numérico standard de índice que pueda ser representativo de la situación de decapitación