The status of shark and ray fishery resources in the Gulf of California: applied research to improve management and conservation

Seasonal surveys were conducted during 1998–1999 in Baja California, Baja California Sur, Sonora, and Sinaloa to determine the extent and activities of artisanal elasmobranch fisheries in the Gulf of California. One hundred and forty–seven fishing sites, or camps, were documented, the majority of which (n = 83) were located in Baja California Sur. Among camps with adequate fisheries information, the great majority (85.7%) targeted elasmobranchs during some part of the year. Most small, demersal sharks and rays were landed in mixed species fisheries that also targeted demersal teleosts, but large sharks were usually targeted in directed drift gillnet or, to a lesser extent, surface longline fisheries. Artisanal fishermen were highly opportunistic, and temporally switched targets depending on the local productivity of teleost, invertebrate, and elasmobranch fishery resources. Major fisheries for small sharks ( 1.5 m, “tiburón”) were minor components of artisanal elasmobranch fisheries in Sonora and Sinaloa, but were commonly targeted during summer and early autumn in Baja California and Baja California Sur. The pelagic thresher shark (Alopias pelagicus) and silky shark (Carcharhinus falciformis) were most commonly landed in Baja California, whereas a diverse assemblage of pelagic and large coastal sharks was noted among Baja California Sur landings. Rays dominated summer landings in Baja California and Sinaloa, when elevated catch rates of the shovelnose guitarfish (Rhinobatos productus, 13.2 individuals/vessel/trip) and golden cownose ray (Rhinoptera steindachneri, 11.1 individuals/vesse/trip) primarily supported the respective fisheries. The Sonoran artisanal elasmobranch fishery was the most expansive recorded during this study, and rays (especially R. productus) dominated spring and summer landings in this state. Seasonal catch rates of small demersal sharks and rays were considerably greater in Sonora than in other surveyed states. Many tiburón populations (e.g., C. leucas, C. limbatus, C. obscurus, Galeocerdo cuvier) have likely been overfished, possibly shifting effort towards coastal populations of cazón and rays. Management recommendations, including conducting demographic analyses using available life history data, determining and protecting nursery areas, and enacting seasonal closures in areas of elasmobranch aggregation (e.g., reproduction, feeding), are proposed. Without effective, enforceable management to sustain or rebuild targeted elasmobranch populations in the Gulf of California, collapse of many fisheries is a likely outcome. (PDF contains 243 pages

Diacritical study of light, electrons, and sound scattering by particles and holes

We discuss the differences and similarities in the interaction of scalar and vector wave-fields with particles and holes. Analytical results are provided for the transmission of isolated and arrayed small holes as well as surface modes in hole arrays for light, electrons, and sound. In contrast to the optical case, small-hole arrays in perforated perfect screens cannot produce acoustic or electronic surface-bound states. However, unlike electrons and light, sound is transmitted through individual holes approximately in proportion to their area, regardless their size. We discuss these issues with a systematic analysis that allows exploring both common properties and unique behavior in wave phenomena for different material realizations.Comment: 3 figure

Effect of the microtubule-associated protein tau on dynamics of single-headed motor proteins KIF1A

Intracellular transport based on molecular motors and its regulation are crucial to the functioning of cells. Filamentary tracks of the cells are abundantly decorated with nonmotile microtubule-associated proteins, such as tau. Motivated by experiments on kinesin-tau interactions [Dixit et al., Science 319, 1086 (2008)] we developed a stochastic model of interacting single-headed motor proteins KIF1A that also takes into account the interactions between motor proteins and tau molecules. Our model reproduces experimental observations and predicts significant effects of tau on bound time and run length which suggest an important role of tau in regulation of kinesin-based transport.publishedVersionFil: Sparacino, Javier. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Sparacino, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Farias, María Gimena. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina.Fil: Farias, María Gimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina.Fil: Farias, María Gimena. Ministerio de Ciencia, Tecnología e Innovación. Agencia Nacional de Promoción de la Investigación, el Desarrollo Tecnológico y la Innovación. Fondo para la Investigación Científica y Tecnológica; Argentina.Fil: Lamberti, Pedro Walter. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Lamberti, Pedro Walter. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Otras Ciencias Física

Noncentral elliptical configuration density

AbstractThe noncentral configuration density, derived under an elliptical model, generalizes and corrects the Gaussian configuration and some Pearson results. Partition theory is then used to obtain explicit configuration densities associated with matrix variate symmetric Kotz type distributions (including the normal distribution), matrix variate Pearson type VII distributions (including t and Cauchy distributions), the matrix variate symmetric Bessel distribution (including the Laplace distribution) and the matrix variate symmetric Jensen-logistic distribution

Experimental investigation of dynamical invariants in bipartite entanglement

The non-conservation of entanglement, when two or more particles interact, sets it apart from other dynamical quantities like energy and momentum. It does not allow the interpretation of the subtle dynamics of entanglement as a flow of this quantity between the constituents of the system. Here we show that adding a third party to a two-particle system may lead to a conservation law that relates the quantities characterizing the bipartite entanglement between each of the parties and the other two. We provide an experimental demonstration of this idea using entangled photons, and generalize it to N-partite GHZ states

Multi-model prediction for demand forecast in water distribution networks

This paper presents a multi-model predictor called Qualitative Multi-Model Predictor Plus (QMMP+) for demand forecast in water distribution networks. QMMP+ is based on the decomposition of the quantitative and qualitative information of the time-series. The quantitative component (i.e., the daily consumption prediction) is forecasted and the pattern mode estimated using a Nearest Neighbor (NN) classifier and a Calendar. The patterns are updated via a simple Moving Average scheme. The NN classifier and the Calendar are executed simultaneously every period and the most suited model for prediction is selected using a probabilistic approach. The proposed solution for water demand forecast is compared against Radial Basis Function Artificial Neural Networks (RBF-ANN), the statistical Autoregressive Integrated Moving Average (ARIMA), and Double Seasonal Holt-Winters (DSHW) approaches, providing the best results when applied to real demand of the Barcelona Water Distribution Network. QMMP+ has demonstrated that the special modelling treatment of water consumption patterns improves the forecasting accuracyPeer ReviewedPostprint (published version

Helium reflectivity and Debye temperature of graphene grown epitaxially on Ru(0001)

It is shown that the surface of an epitaxial graphene monolayer grown on Ru(0001) could be used as a quite efficient external mirror for He-atom microscopy, with a specular reflectivity of 20% of the incident beam. Furthermore, the system is stable up to 1150 K, and the He reflectivity remains almost unchanged after exposure to air. Additionally, the high reflectivity for H2 molecules (11%) opens up the development of a H2 microprobe suitable for lithography. The Debye temperature for this epitaxial graphene monolayer has been determined from a study of the temperature dependence of the He specular intensity as a function of incident parameters. A value of 1045 K has been obtained, which is much higher than the 590 K reported for graphite under similar conditions, and close to the value of 1287 K calculated for isolated grapheneThis work was supported by the Ministerio de Educación y Ciencia through the program CONSOLIDER-INGENIO on Molecular Nanoscience (Project No. CSD 2007-00010), Project No. FIS2010-18847, and a Juan de la Cierva grant (A.P.), and by Comunidad de Madrid through the program NANOBIOMAGNE

Runner’s Profile and Propensity to Sports Injury

Se evalúa las relaciones entre el perfil sociodemográfico, la accidentabilidad y la propensión al accidente de los participantes en tres eventos deportivos: Zurich Marató de Barcelona, Cros de Muntanya Can Caralleu, y Marató Borredà-Xtrail. Una adaptación del cuestionario de propensión al accidente deportivo (PAD-22) de Latorre y Pantoja (2013) fue administrado a un total de 237 corredores. Los principales resultados muestran que: los corredores tienden a ser mayoritariamente varones, de entre 30 y 46 años, asalariados, con estudios postobligatorios, con experiencia previa en eventos de larga distancia, entrenan una media de 4 veces y un total de 7 horas a la semana; y los corredores de la maratón por asfalto tienen una sobreestimación de la Competencia Percibida y grados de Competitividad mayores a los corredores por montañaThis study evaluates relations between sociodemographic profile, accident rate and accident’s propensity of three sport events participants: Zurich Marató de Barcelona, Cros de Muntanya Can Caralleu & Marató Borredà-Xtrail. The used method was an adaptation of the sports accident prone scale (PAD-22) from Latorre y Pantoja (2013), to 237 runners. The main results show that: runners tend to be mostly men, aged of 30-46 years, are salaried, have post-compulsory studies, have some experience in long distance events, train a mean of 4 times and more than 7 hours per week; and marathon asphalt runners have a overestimation of Perceived Competence and elevated degrees of Competitiveness, more than trail runnersEste trabajo forma parte del Proyecto de Investigación, con código 2014 PINEF 00006 y ha sido realizado con el apoyo del programa de becas predoctorales del Instituto Nacional de Educación Física de Cataluña (PINEFC-2015). Agradecemos el apoyo dado por el INEFC en la realización de este estudio, puesto que, sin su cobijo, no se hubiera podido llevar a cabo con las mismas condicione

Emergence of the pointer basis through the dynamics of correlations

We use the classical correlation between a quantum system being measured and its measurement apparatus to analyze the amount of information being retrieved in a quantum measurement process. Accounting for decoherence of the apparatus, we show that these correlations may have a sudden transition from a decay regime to a constant level. This transition characterizes a non-asymptotic emergence of the pointer basis, while the system-apparatus can still be quantum correlated. We provide a formalization of the concept of emergence of a pointer basis in an apparatus subject to decoherence. This contrast of the pointer basis emergence to the quantum to classical transition is demonstrated in an experiment with polarization entangled photon pairs.Comment: 4+2 pgs, 3 figures. Title changed. Revised version to appear on PR