Wave-like solutions for nonlocal reaction-diffusion equations: A toy model

Traveling waves for the nonlocal Fisher Equation can exhibit much more complex behaviour than for the usual Fisher equation. A striking numerical observation is that a traveling wave with minimal speed can connect a dynamically unstable steady state 0 to a Turing unstable steady state 1, see [12]. This is proved in [1, 6] in the case where the speed is far from minimal, where we expect the wave to be monotone. Here we introduce a simplified nonlocal Fisher equation for which we can build simple analytical traveling wave solutions that exhibit various behaviours. These traveling waves, with minimal speed or not, can (i) connect monotonically 0 and 1, (ii) connect these two states non-monotonically, and (iii) connect 0 to a wavetrain around 1. The latter exist in a regime where time dynamics converges to another object observed in [3, 8]: a wave that connects 0 to a pulsating wave around 1. © 2013 EDP Sciences

(η6-Benzophenone)(η5-penta­methyl­cyclo­penta­dien­yl)ruthenium(II) tetra­phenyl­borate

The structure of the title compound, [Ru(C10H15)(C13H10O)](C24H20B), consists of discrete [Cp*Ru(II)benzophenone] cations and tetra­phenyl­borate anions (Cp* = penta­methyl­cyclo­penta­dien­yl). Tethering the Cp*Ru group to one aryl ring of benzophenone results in average values of 1.42 (1) and 1.38 (1) Å for the C—C bond lengths in the Ru-tethered and untethered phenyl rings, respectively. The dihedral angle between the benzene and phenyl rings of the benzophenone group is 50.5 (1)°

Geography but not alternative host species explain the spread of raccoon rabies virus in Vermont

In North America, the raccoon-associated variant of rabies virus (RRV) is of special concern, given its relatively rapid spread throughout the eastern USA and its potential public health impact due to high raccoon host densities in urban areas. Northward expansion of this epizootic included an outbreak in the Canadian province of Quebec in 2006–2009 due to trans-border spread from the State of Vermont. To inform a more proactive approach to future control efforts, this study uses phylogenetic analyses to explore the role of geography and alternative carnivore hosts in the dynamics of RRV spread within Vermont. Specifically, we sought to examine whether striped skunks, a species frequently infected by RRV, could be part of the maintenance host community. Whole genome sequencing of 160 RRV samples from Vermont and neighbouring US states were used for fine-scale phylogeographic analyses. Results, together with the complete surveillance record of raccoon rabies since its entry into Vermont in 1994, document incursions by two distinct viral lineages and identify topographical features of the landscape which have significantly influenced viral spread, resulting in a complex distribution pattern of viral variants throughout the state. Results of phylogenetic cluster analysis and discrete state reconstruction contained some evidence of skunk-to-skunk and skunk-to-raccoon transmission but overall failed to support a role for skunks as alternative maintenance hosts

Salida de campo bajo el enfoque constructivista en el curso de bienestar animal en la Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata

El constructivismo concibe al alumno como el arquitecto de su aprendizaje y automotivación. Este trabajo analiza la salida de campo como herramienta en el proceso pedagógico del curso de Bienestar Animal (BA) en la Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata. El curso de BA rompe así con la rutina de clases áulicas trasladando el aprendizaje al medio rural, entendiendo la motivación que esto genera. Se observa que la salida contribuye a transmitir conceptos de BA y fomenta la formación científica, posibilitando el desarrollo de técnicas y estrategias en las tareas de observación, análisis, interpretación y diagnóstico in situ, inherentes al proceso científico. La metodología conecta ideas previamente consensuadas por los actores, permitiendo su participación a través de la planificación y fundamentación didáctica. En el diseño de la salida, las Tecnologías de la Información y de la Comunicación facilitan la búsqueda y redistribución de información que los alumnos usan para su formación. La importancia de esta herramienta es la motivación, la adquisición de destreza científico – práctica, la promoción de la capacidad de observación y análisis; fomentando la comprensión de parte de la realidad rural junto a la adquisición del espíritu reflexivo del alumno. La tarea encomendada al alumnado, es la observación del objeto de estudio desde lo general a lo particular. Mediante directrices se los guía, para que realicen un análisis y diagnóstico que permita comprender la situación. No solamentela integración de teoría y práctica, mediante la interacción, permite la autoformación y el fomento de la creatividad frente a problemas concretos, sino también, la capacidad del alumno de comparar lo que piensa y siente, con lo que está escrito en los libros. Consideramos que la salida de campo es una herramienta que constituye una manera vivencial de asimilar, comprender e interpretar el medio rural.Facultad de Ciencias Agrarias y Forestale

El cine debate como herramienta para la enseñanza en el curso de bienestar animal: estudio de caso en la Facultad de Ciencias Agrarias y Forestales, UNLP

Existen herramientas muy valiosas utilizadas como medio de enseñanza en el ámbito universitario. El cine, herramienta narrativa audiovisual, potencia la capacidad de los estudiantes para la reflexión y el análisis; conectando la emoción, los sentimientos, los miedos y los sueños de las personas (Cappelletti et al., 2007). De la Torre (1996, citado por Cappelletti et al., 2007), considera que el cine, es utilizado como recurso didáctico, y el docente actúa como mediador y transformador de la ficción en códigos de aprendizaje. El presente estudio de caso analiza la utilización del cine-debate como herramienta didáctica en el proceso educativo del curso de extensión de Bienestar Animal (BA) en la Facultad de Ciencias Agrarias y Forestales (UNLP). Esta metodología se llevó a cabo durante 2014 y 2015. En un primer momento, se dictaron los contenidos teóricos del tema en cuestión. Previamente a la proyección del film, se entregó a los estudiantes una guía sobre la película y una serie de preguntas disparadoras, con intención de generar una actitud valorativa en la audiencia. Posteriormente, se proyectó una película acorde a la temática, con el fin de incorporar y reforzar los contenidos teóricos. Finalizada la proyección, se estimuló a los alumnos a realizar un taller debate, fortaleciendo así la instancia de análisis y reflexión. Se observó que los alumnos participaron activamente brindando sus puntos de vista, e interactuando tanto con los docentes como entre ellos. Esta interacción es significativa en la construcción de nuevos conocimientos. En la enseñanza de las ciencias agropecuarias, es importante el uso del cine-debate pues acerca, de manera audiovisual, conceptos o procesos que no son fáciles de apreciar en una imagen fija. Los alumnos encuentran que esta metodología es una práctica motivadora de intercambio de opiniones y conceptos, por este motivo seguirá siendo utilizada en el curso de BA.Facultad de Ciencias Agrarias y Forestale

Recruitment and retention of participants in randomised controlled trials: a review of trials funded and published by the United Kingdom Health Technology Assessment Programme

Background Substantial amounts of public funds are invested in health research worldwide. Publicly funded randomised controlled trials (RCTs) often recruit participants at a slower than anticipated rate. Many trials fail to reach their planned sample size within the envisaged trial timescale and trial funding envelope. Objectives To review the consent, recruitment and retention rates for single and multicentre randomised control trials funded and published by the UK's National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Programme. Data sources and study selection HTA reports of individually randomised single or multicentre RCTs published from the start of 2004 to the end of April 2016 were reviewed. Data extraction Information was extracted, relating to the trial characteristics, sample size, recruitment and retention by two independent reviewers. Main outcome measures Target sample size and whether it was achieved; recruitment rates (number of participants recruited per centre per month) and retention rates (randomised participants retained and assessed with valid primary outcome data). Results This review identified 151 individually RCTs from 787 NIHR HTA reports. The final recruitment target sample size was achieved in 56% (85/151) of the RCTs and more than 80% of the final target sample size was achieved for 79% of the RCTs (119/151). The median recruitment rate (participants per centre per month) was found to be 0.92 (IQR 0.43–2.79) and the median retention rate (proportion of participants with valid primary outcome data at follow-up) was estimated at 89% (IQR 79–97%). Conclusions There is considerable variation in the consent, recruitment and retention rates in publicly funded RCTs. Investigators should bear this in mind at the planning stage of their study and not be overly optimistic about their recruitment projections

Recruitment and retention of participants in randomised controlled trials: a review of trials funded by the United Kingdom health technology assessment programme

Background Substantial amounts of public funds are invested in health research worldwide. Publicly funded randomised controlled trials (RCTs) often recruit participants at a slower than anticipated rate. Many trials fail to reach their planned sample size within the envisaged trial timescale and trial funding envelope. Objectives To review the consent, recruitment and retention rates for single and multicentre randomised control trials funded and published by the UK's National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Programme. Data sources and study selection HTA reports of individually randomised single or multicentre RCTs published from the start of 2004 to the end of April 2016 were reviewed. Data extraction Information was extracted, relating to the trial characteristics, sample size, recruitment and retention by two independent reviewers. Main outcome measures Target sample size and whether it was achieved; recruitment rates (number of participants recruited per centre per month) and retention rates (randomised participants retained and assessed with valid primary outcome data). Results This review identified 151 individually RCTs from 787 NIHR HTA reports. The final recruitment target sample size was achieved in 56% (85/151) of the RCTs and more than 80% of the final target sample size was achieved for 79% of the RCTs (119/151). The median recruitment rate (participants per centre per month) was found to be 0.92 (IQR 0.43–2.79) and the median retention rate (proportion of participants with valid primary outcome data at follow-up) was estimated at 89% (IQR 79–97%). Conclusions There is considerable variation in the consent, recruitment and retention rates in publicly funded RCTs. Investigators should bear this in mind at the planning stage of their study and not be overly optimistic about their recruitment projections

Genomic DNA Sequences from Mastodon and Woolly Mammoth Reveal Deep Speciation of Forest and Savanna Elephants

This study compares three extant elephants species - forest, savanna, and Asian - to extinct mammoth and mastodon. Surprisingly, forest and savanna elephants in Africa today are as distinct from each other as mammoth and Asian elephants

Hyperbolic traveling waves driven by growth

We perform the analysis of a hyperbolic model which is the analog of the Fisher-KPP equation. This model accounts for particles that move at maximal speed $\epsilon^{-1}$ (\epsilon\textgreater{}0), and proliferate according to a reaction term of monostable type. We study the existence and stability of traveling fronts. We exhibit a transition depending on the parameter $\epsilon$: for small $\epsilon$ the behaviour is essentially the same as for the diffusive Fisher-KPP equation. However, for large $\epsilon$ the traveling front with minimal speed is discontinuous and travels at the maximal speed $\epsilon^{-1}$. The traveling fronts with minimal speed are linearly stable in weighted $L^2$ spaces. We also prove local nonlinear stability of the traveling front with minimal speed when $\epsilon$ is smaller than the transition parameter.Comment: 24 page