Tests for the asymptotic behaviour of the gamma^* --> gamma pi^0 form factor

The gamma^* --> gamma pi^0 transition measured at different photon virtualities already provides us with a clean test for the behaviour of the pi^0 gamma^* gamma off-shell axial anomaly at large time-like squared momenta. It also allows reliable predictions for the branching ratio of heavy quarkonium decays into omega pi^0.Comment: Latex, 7 pages + 1 .ps figure, comments on the Brodsky-Lepage limit and 5 new references adde

Complex dynamics in a thermosolutal convection loop

We present a study of the dynamics of a heated binary mixture in a loop. For both negative and positive sign of the separation parameter the system has a rich behaviour, in the first case we encounter a super-critical Hopf Bifurcation and in the latter the system becomes chaotic.2022/202

Considerations on the electronic control system for autonomous underwater vehicle

Peer Reviewe

Extended Ordered Paired Comparison Models with Application to Football Data from German Bundesliga

A general paired comparison model for the evaluation of sports competitions is proposed. It efficiently uses the available information by allowing for ordered response categories and team-specific home advantage effects. Penalized estimation techniques are used to identify clusters of teams that share the same ability. The model is extended to include team-specific explanatory variables. It is shown that regularization techniques allow to identify the contribution of explanatory variables to the success of teams. The usefulness of the methods is demonstrated by investigating the performance and its dependence on the budget for football teams of the German Bundesliga

Development of a control system for an autonomous underwater vehicle

This work proposes the development of a control system for an autonomous underwater vehicle dedicated to the observation of the oceans. The vehicle, a hybrid between Autonomous Underwater Vehicles (AUVs) and Autonomous Surface Vehicles (ASV), moves on the surface of the sea and makes vertical immersions to obtain profiles of a water column, according to a pre-established plan. The displacement of the vehicle on the surface allows the navigation through GPS and telemetry communication by radio-modem. The vehicle is 2300mm long by 320mm wide. It weighs 85kg and reaches a maximum depth of 30m. A control system based on an embedded computer is designed and developed for this vehicle that allows a vehicle's autonomous navigation. This control system has been divided into navigation, propulsion, safety and data acquisition subsystems.Peer ReviewedPostprint (author’s final draft

Effects of the invasive aquatic snail Potamopyrgus antipodarum (Gray, 1853) on ecosystem properties and services

Ecosystems provide benefits to humans, including provisioning, regulating, and cultural services. However, invasive species can threaten ecosystem well-functioning and services provided. One invasive species with such potential is the New Zealand mud snail (NZMS) Potamopyrgus antipodarum. The aims of this study are focused on the quantitative review of (1) the NZMS impacts on ecosystem properties and their direct links with ecosystem services, and (2) the ecosystem services that can be affected by the NZMS. The high density reached by this species in most of the invaded ecosystems and its highly competitive ability affect ecosystem structure and functioning. However, some facilitation processes on native species may result in an improvement of some services. The NZMS tends to positively affect cultural services (88% positive cases) but negatively to provisioning services (77% of cases). Regarding, regulating and maintenance services, the proportions of positive and negative effects were similar (45% vs 36%, respectively). Therefore, the NZMS is a species with numerous negative impacts on ecosystem services. However, ecosystem services related to health (e.g., dilution effect against parasites) and research (e.g., biomonitoring) are cultural services that the NZMS can improve. No economic assessment of the impacts of the NZMS is available in the literature

Power system of the Guanay II AUV

Guanay II is an autonomous underwater vehicle (AUV) designed to perform measurements in a water column. In this paper the aspects of the vehicle’s power system are presented with particular focus on the power elements and the state of charge of the batteries. The system performs both measurement and monitoring tasks and also controls the state of charge (SoC) of the batteries. It allows simultaneous charging of all batteries from outside the vehicle and has a wireless connection/disconnection mode. Guanay II uses a NiCd battery and for this reason the current integration as a SoC methodology has been selected. Moreover, it has been validated that it is possible to obtain instant consumption from the SoC circuit. Finally, laboratory and vehicle navigation tests have been performed to validate the correct operation of the systems and the reliability of the measured dataPostprint (published version

The Physcomitrella patens unique alpha-dioxygenase participates in both developmental processes and defense responses

[Background] Plant α-dioxygenases catalyze the incorporation of molecular oxygen into polyunsaturated fatty acids leading to the formation of oxylipins. In flowering plants, two main groups of α-DOXs have been described. While the α-DOX1 isoforms are mainly involved in defense responses against microbial infection and herbivores, the α-DOX2 isoforms are mostly related to development. To gain insight into the roles played by these enzymes during land plant evolution, we performed biochemical, genetic and molecular analyses to examine the function of the single copy moss Physcomitrella patens α-DOX (Ppα-DOX) in development and defense against pathogens.[Results] Recombinant Ppα-DOX protein catalyzed the conversion of fatty acids into 2-hydroperoxy derivatives with a substrate preference for α-linolenic, linoleic and palmitic acids. Ppα-DOX is expressed during development in tips of young protonemal filaments with maximum expression levels in mitotically active undifferentiated apical cells. In leafy gametophores, Ppα-DOX is expressed in auxin producing tissues, including rhizoid and axillary hairs. Ppα-DOX transcript levels and Ppα-DOX activity increased in moss tissues infected with Botrytis cinerea or treated with Pectobacterium carotovorum elicitors. In B. cinerea infected leaves, Ppα-DOX-GUS proteins accumulated in cells surrounding infected cells, suggesting a protective mechanism. Targeted disruption of Ppα-DOX did not cause a visible developmental alteration and did not compromise the defense response. However, overexpressing Ppα-DOX, or incubating wild-type tissues with Ppα-DOX-derived oxylipins, principally the aldehyde heptadecatrienal, resulted in smaller moss colonies with less protonemal tissues, due to a reduction of caulonemal filament growth and a reduction of chloronemal cell size compared with normal tissues. In addition, Ppα-DOX overexpression and treatments with Ppα-DOX-derived oxylipins reduced cellular damage caused by elicitors of P. carotovorum.[Conclusions] Our study shows that the unique α-DOX of the primitive land plant P. patens, although apparently not crucial, participates both in development and in the defense response against pathogens, suggesting that α-DOXs from flowering plants could have originated by duplication and successive functional diversification after the divergence from bryophytes.This work was supported by Agencia Nacional de Investigación e Innovación (ANII) [grants FCE2007_376, FCE2011_6095, fellowships BE_POS_2009_726 (A. Castro) and BE_POS_2010_2533 (L. Machado)], UdelaR Uruguay/CSIC Spain (Joint project), the Swedish Research Council, and Programa de Desarrollo de las Ciencias Básicas (PEDECIBA) Uruguay. The Ppα-DOX cDNA was obtained from the RIKEN Biological Research Center, Tsukuba, Japan

Autoestima y agresividad en estudiantes del cuarto grado de secundaria de una Institución Educativa de la ciudad de Huancayo, 2019

La presente investigación lleva por título “Autoestima y Agresividad en Estudiantes del Cuarto Grado de Secundaria de una Institución Educativa de la Ciudad de Huancayo, 2019”, se ejecutó debido a la escasez y en respuesta a las pequeñas investigaciones que existen en nuestra localidad. Este estudio consiste en extender los conocimientos de las variables mencionadas a través del cual se puede llegar a prevenir la agresión en adolescentes y fortalecer la autoestima de los mismos en el futuro. Ante todo, este trabajo tuvo por objetivo determinar la relación que existe entre autoestima y agresividad en estudiantes del cuarto grado de secundaria de una Institución Educativa de la ciudad de Huancayo. De tal manera se realizó un estudio de nivel correlacional, diseño no experimental, de corte transversal, con una muestra de tipo censal conformada por 132 estudiantes entre las edades de 14 y 15 años pertenecientes a una Institución Educativa de la ciudad de Huancayo, donde se empleó el inventario de autoestima de Copersmith y el Cuestionario de Agresión de Buss y Perry, cuya validez se llegó a determinar mediante Juicio de expertos y la confiabilidad fue establecida por el análisis estadístico de las pruebas piloto ejecutadas al 10% de la muestra, por lo que arrojó un coeficiente Alfa de Crombach de 0.899 y 0,921 respectivamente. El procesamiento y análisis de los datos se realizó mediante el paquete estadístico SPSS V.24, cuyo resultado demuestra que hay relación significativa e inversa en las variables Autoestima y Agresividad en adolescentes del cuarto grado de secundaria ya que se visualiza que el P valor (sig._bilateral), p=0,00 < 0.05, el nivel de confianza, asimismo la relación que existe es negativa ya que Rho = -0.484, se concluye que a considerable autoestima, mínima será la agresividad entre los adolescentes. Por lo que se recomienda sensibilizar a la población estudiantil, la importancia de tener una autoestima alta, de esta manera disminuir la agresión en los adolescentes.Tesi