Stochastic pump of interacting particles

We consider the overdamped motion of Brownian particles, interacting via particle exclusion, in an external potential that varies with time and space. We show that periodic potentials that maintain specific position-dependent phase relations generate time-averaged directed current of particles. We obtain analytic results for a lattice version of the model using a recently developed perturbative approach. Many interesting features like particle-hole symmetry, current reversal with changing density, and system-size dependence of current are obtained. We propose possible experiments to test our predictions.Comment: 4 pages, 2 figure

Large Polarization and Susceptibilities in Artificial Morphotropic Phase Boundary PbZr1−xTixO3 Superlattices

The ability to produce atomically precise, artificial oxide heterostructures allows for the possibility of producing exotic phases and enhanced susceptibilities not found in parent materials. Typical ferroelectric materials either exhibit large saturation polarization away from a phase boundary or large dielectric susceptibility near a phase boundary. Both large ferroelectric polarization and dielectric permittivity are attained wherein fully epitaxial (PbZr0.8Ti0.2O3)n/(PbZr0.4Ti0.6O3)2n (n = 2, 4, 6, 8, 16 unit cells) superlattices are produced such that the overall film chemistry is at the morphotropic phase boundary, but constitutive layers are not. Long- (n ≥ 6) and short-period (n = 2) superlattices reveal large ferroelectric saturation polarization (Ps = 64 µC cm−2) and small dielectric permittivity (εr ≈ 400 at 10 kHz). Intermediate-period (n = 4) superlattices, however, exhibit both large ferroelectric saturation polarization (Ps = 64 µC cm−2) and dielectric permittivity (εr = 776 at 10 kHz). First-order reversal curve analysis reveals the presence of switching distributions for each parent layer and a third, interfacial layer wherein superlattice periodicity modulates the volume fraction of each switching distribution and thus the overall material response. This reveals that deterministic creation of artificial superlattices is an effective pathway for designing materials with enhanced responses to applied bias

Swine production simulation model: LIFE SIM

Supported by the CGIAR Systemwide Livestock ProgrammeNon-ruminant animals are essential in many resource-poor production systems, particularly in Asia. The feeding strategies are as varied as the different agro ecosystems, thus increasing the challenge faced by researchers and extension agents in the search for appropriate solutions to feeding limitations. Systems analysis provides a unique opportunity to translate existing knowledge into process-based models that can be used to assess year-round feeding strategies at the farm level. Although livestock models have been developed to address similar situations for ruminant animals, swine are seldom included. The present work describes a swine model that analyzes the bioeconomic response to feeding strategies in different production systems. This swine model has been incorporated into the software Livestock Feeding Strategies Simulation Model (LIFE-SIM) complementing the existing models for ruminant species: Dairy, Beef, Goat, and Buffalo (León-Velarde et al., 2006) The model simulates a confined group of animals (at least two females or males) with a weight ranging from 15 to 120 kg, under either an ad libitum or controlled feeding regime with a feed value characterized in terms of dry matter (%), metabolizable energy (ME/kg), crude fiber (%), lysine (%), methionine + cystine (%), threonine (%), and tryptophan (%). The model can store a number of different rations and their prices allowing a comparison during a defined fattening period. Weight gain and the bioeconomic performance of each ration can then be estimated and analyzed

Health evaluation of a pronghorn antelope population in Oregon

During 1996 and 1997, the U.S. Fish and Wildlife Service conducted a study to determine the cause(s) of population decline and low survival of pronghorn antelope (Antilocapra americana) fawns on Hart Mountain National Antelope Refuge (HMNAR) located in southeastern Oregon (USA). As part of that study, blood, fecal, and tissue samples from 104 neonatal fawns, 40 adult does, and nine adult male pronghorns were collected to conduct a health evaluation of the population. Physiological parameters related to nutrition and/or disease were studied. No abnormalities were found in the complete blood cell counts of adults (n = 40) or fawns (n = 44 to 67). Serum total protein and blood urea nitrogen (BUN) levels were lower compared to other pronghorn populations. Does had mean BUN values significantly lower (P < 0.001) in December 1996 than March 1997. Serum copper (Cu) levels in does (range 0.39 to 0.74 ppm) were considered marginal when compared to domestic animals and other wild ungulates. Fawns had low (0.28 ppm) Cu levels at birth and reached the does' marginal values in about 3 days. Whole blood, serum and liver selenium (Se) levels were considered marginal to low in most segments of the pronghorn population. However, serum levels of vitamin E (range 1.98 to 3.27 μg/ml), as determined from the does captured in March, were apparently sufficient to offset any signs of Se deficiency. No clinical signs of Cu or Se deficiency were observed. Fifty-five of 87 dead fawns were necropsied. Trauma, due to predation by coyotes (Canis latrans), accounted for 62% of the mortality during mid-May to mid-July of each year. Other causes included predation by golden eagles (Aquila chrysaetos) (4%), dystocia (2%), septicemic pasteurellosis (4%), starvation (5%), and unknown (23%). Adult females were tested for serum neutralizing antibodies to Brucella spp. (n = 20, negative), Leptospira interrogans (n = 20, negative), bluetongue virus (n = 20, 35% positive), epizootic hemorrhagic disease virus (n = 20, 30% positive), respiratory syncytial virus (n = 18, negative), parainfluenza virus type 3 (n = 18, 67% positive), infectious bovine rhinotracheitis (n = 18, negative), and bovine viral diarrhea (n = 18, negative). Considering the parameters examined, we found no apparent predisposing factors to mortality including those killed by coyotes, but some nutritional parameters suggest that pronghorns on HMNAR exist on a diet low in protein and Se and marginal in Cu. The effect these factors have on the population is not known

First report of the genus Physaloptera (Nematoda: Physalopteridae) in Lithobates montezumae (Anura: Ranidae) from Mexico

AbstractNematode third stage larvae of the genus Physaloptera (Nematoda: Physalopteridae) were recovered from the stomach of Lithobates montezumae (Anura: Ranidae) collected in the Pedregal de San Angel Ecological Reserve in Mexico D. F. (19º11’6.50” N, 99º11’41.42” W; 2 312 m asl). The morphology of the larvae is briefly described and a list of previously recorded localities and hosts in Mexico is given. This study is the first record of Physaloptera sp. parasitizing L. montezumae, and also represents the first helminthological record for anurans in this locality, as well as a new locality record for the nematode genus

Gestión eficiente de las economías locales a través de estrategias administrativas/Efficient management of local economies through administrative strategies

La gestión de la economía local plantea retos al integrarse al sector productivo como uno de sus ejes de crecimiento, este estudio plantea un análisis de la dinámica de estrategias administrativas aplicadas en las microempresas de la ciudad de Macas y su incidencia en la eficiencia para promover el desarrollo del espacio, convirtiéndose éstas en las dos variables de estudio: la gestión de las economías locales y las estrategias administrativas, la metodología de trabajo a utilizar comienza definiendo una investigación de tipo cuantitativa y cualitativa, no experimental, denostándose su independencia a través del método Chi cuadrado determinándose que menos del 50% de negocios aplica algún tipo de estrategia administrativa con una incidencia directa en la gestión de la economía local que trabaja de manera aislada del sector productivo creándose una herramienta a través de la cual se pueda crear una sinergia para lograr el objetivo común que permita eficiencia en el mercado y la gestión pública. Efficient management of local economies through administrative strategies is a stady of the management of the local economy poses challenges when integrating into the productive sector as one of its growth axes, this study proposes an analysis of the dynamics of administrative strategies applied in the micro enterprises of the city of Macas and its impact on efficiency to promote the development of space, these becoming the two variables of study: the management of local economies and administrative strategies, the work methodology to be used begins defining a quantitative and qualitative research, not experimental, denoting its independence through the method Chi square determining that less than 50% of businesses apply some kind of administrative strategy with a direct impact on the management of the local economy that works in isolation from the productive sector, creating a tool through which synergy can be created to achieve the common goal that allows efi science in the market and public management. Palabras clave: Administración, Economía, desarrollo, negocios, gestión, estrategias. Keywords: Administration, Economy, development, business, management, strategies

Synthesis and characterization of copper coatings on polyimide membranes (PIR 003)

The formation of stable metallic/polymeric joints is a huge challenge in the materials sciences. Adhesion requires interphase that is able to specifically interact with the metallic phase. The primary amino groups exhibit copolymers as highly reactive to metal surfaces. This article will give a better understanding of the mechanisms of chemo-absorption by chemical functionalization of polyimides, as well as in the wet development of metallization of materials based on H2 reduction in polymers. And it will be evidenced by comparisons by measures of polymer/metal characterization.Campus Arequip

Efecto de la adición de organo-hidrotalcita a un suelo agrícola en el comportamiento de los fungicidas tebuconazol y metalaxil bajo condiciones reales de campo

2 páginas.-- 2 tablas.-- 2 referencias.-- Poster presentado en XXIV Reunión de la Sociedad Española de Arcillas Sevilla. Libro de Resúmenes: Noviembre de 2015 en Sevilla.Existen numerosos trabajos que abordan las aplicaciones de arcillas naturales, inalteradas o modificadas, como adsorbentes de pesticidas para la depuración de aguas e incluso para actuar como soportes en formulaciones de liberación lenta del pesticida o como barreras inmovilizantes en suelos (Cornejo et al., 2008). La mayoría de estos estudios se han realizado bajo condiciones controladas en el laboratorio y usando minerales de la arcilla naturales del grupo de las esmectitas. En los últimos años, ha aumentado el interés por explotar las propiedades adsorbentes de los hidróxidos dobles laminares (HDLs), también conocidos como hidrotalcitas (HTs) o arcillas aniónicas, cuyas características estructurales guardan cierta relación con las de las esmectitas (Cornejo et al., 2008). Los LDHs consisten en láminas del tipo brucita de un metal divalente con sustituciones isomórficas que proporcionan a las láminas una carga permanente positiva y que es compensada con aniones intercambiables que se sitúan en el espacio interlaminar. Aunque los resultados obtenidos hasta ahora ponen de manifiesto la elevada capacidad de adsorción de los LDHs para muchos pesticidas y la versatilidad que les confiere la posibilidad de modificarlos mediante la intercalación de aniones orgánicos en el espacio interlaminar (Celis et al., 2014), su utilidad como enmendantes para aumentar la capacidad de adsorción de los suelos bajo condiciones ambientales reales aún no ha sido evaluada.Este trabajo ha sido financiado por el Ministerio de Economía y Competitividad (MINECO) a través de los proyectos AGL2011-23779 y AGL2014-51897-R y por la Junta de Andalucía a través del Grupo de Investigación AGR-264, con parte de fondos FEDER-FSE. R. López-Cabeza agradece al MINECO la concesión de una beca pre-doctoral de FPI asociada al proyecto AGL2011-23779.Peer reviewe

Effect of synthetic clay and biochar addition on dissipation and enantioselectivity of tebuconazole and metalaxyl in an agricultural soil: Laboratory and field experiments

10 páginas.-- 4 figuras.-- 3 tablas.-- referencias.-- Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.agee.2016.05.017Laboratory and field experiments were conducted to assess how the addition of oleate-modified hydrotalcite (clay) and biochar (BC) to an agricultural soil affected the sorption, leaching, persistence, and enantiomeric composition of soil residues of two chiral fungicides, tebuconazole and metalaxyl. Laboratory experiments showed that the sorption of both fungicides ranked as follows: unamended soil < BC-amended soil < clay-amended soil. The addition of clay at a rate of 1% increased metalaxyl soil sorption coefficient (Kd) from 0.34 to 3.14 L kg−1 and that of tebuconazole from 2.4 to 47.4 L kg−1. In our experimental set-up, field plots were either unamended or amended with clay (2 t ha−1) or BC (4 t ha−1), and subsequently treated with a mixture of tebuconazole and metalaxyl at 3 and 6 kg ha−1, respectively. The leaching, persistence, and enantiomer composition of fungicides residues were monitored by sampling at different soil depths (0–5, 5–10, 10–20 cm) for 98 days. No significant changes in the scarce mobility and long persistence of tebuconazole upon amending the soil with clay or BC were observed. In contrast, sorption to clay and BC particles reduced the leaching and degradation of metalaxyl and the clay increased its persistence in the topsoil compared to the unamended soil. The enantioselective analysis of tebuconazole and metalaxyl soil residues indicated that tebuconazole remained mostly racemic along the experiment, whereas for metalaxyl the concentration of S-enantiomer was greater than the concentration of R-enantiomer, more so at longer experimental times and deeper horizons. Nevertheless, for the top 0–5 cm soil layer metalaxyl remained more racemic in clay- and BC-amended soil than in unamended soil. Our results show that addition of amendments with high sorptive capacities can be beneficial in reducing leaching and degradation losses of chiral pesticide enantiomers from the topsoil, and that sorption by the amendments can influence the final enantiomeric composition of pesticide residues.This work was financed by the Spanish Ministry of Economy and Competitiveness (MINECO Projects AGL2011-23779, AGL2013-48446-C3-1-R and AGL2014-51897-R) and Junta de Andalucía (JA Research Group AGR-264), with FEDER-FSE funds. R. López-Cabeza thanks MINECO for a pre-doctoral fellowship linked to the Project AGL2011-23779 (Grant BES-2012-059945). The authors also thank P. Franco (Chiral Technologies Europe) and I. Girón (IRNAS) for their technical assistancePeer reviewe