Characteristics of mixed Meloidogyne arenaria and M. incognita populations in flue-cured tobacco

Des expériences en champ ont été poursuivies pendant deux ans afin de caractériser l'association de #Meloidogyne arenaria race 2 (populations Pelion et Govan) et de #M. incognita race 3 sur des plants de tabac résistant à #M. incognita races 1 et 3 ainsi que sur des plants de tabac sensible aux deux espèces. A été également étudié l'effet potentiel de l'infestation par #M. arenaria sur la résistance de l'hôte à #M. incognita races 1 et 3. L'identité spécifique des #Meloidogyne a été établie à la récolte en se fondant sur la longueur des juvéniles de deuxième stade. Les plants de tabac résistants à #M. incognita ne se sont pas montrés prédisposés à l'infestation par #M. incognita lorsqu'ils étaient infestés par #M. arenaria race 2. Le développement des galles sur les racines de tabac résistant à #M. incognita est plus important dans le cas de la population Pelion que dans celui de la population Govan de #M. arenaria. Lors d'infestations mixtes par #M. incognita et #M. arenaria, et avec des traitements équivalents sur plants de tabac sensible, la proportion de la population Govan de #M. arenaria est toujours plus importante (P = 0,05) que celle de la population Pelion. (Résumé d'auteur

Exact quantum states of a general time-dependent quadratic system from classical action

A generalization of driven harmonic oscillator with time-dependent mass and frequency, by adding total time-derivative terms to the Lagrangian, is considered. The generalization which gives a general quadratic Hamiltonian system does not change the classical equation of motion. Based on the observation by Feynman and Hibbs, the propagators (kernels) of the systems are calculated from the classical action, in terms of solutions of the classical equation of motion: two homogeneous and one particular solutions. The kernels are then used to find wave functions which satisfy the Schr\"{o}dinger equation. One of the wave functions is shown to be that of a Gaussian pure state. In every case considered, we prove that the kernel does not depend on the way of choosing the classical solutions, while the wave functions depend on the choice. The generalization which gives a rather complicated quadratic Hamiltonian is simply interpreted as acting an unitary transformation to the driven harmonic oscillator system in the Hamiltonian formulation.Comment: Submitted to Phys. Rev.

Avoided Critical Behavior in a Uniformly Frustrated System

We study the effects of weak long-ranged antiferromagnetic interactions of strength $Q$ on a spin model with predominant short-ranged ferromagnetic interactions. In three dimensions, this model exhibits an avoided critical point in the sense that the critical temperature $T_c(Q=0)$ is strictly greater than $\lim_{Q\to 0} T_c(Q)$. The behavior of this system at temperatures less than $T_c(Q=0)$ is controlled by the proximity to the avoided critical point. We also quantize the model in a novel way to study the interplay between charge-density wave and superconducting order.Comment: 32 page Latex file, figures available from authors by reques

Mental health of veterinary nurses and student veterinary nurses: A scoping review

Background: Research has found veterinarians around the world to be at high risk of mental health problems, but far less research has examined veterinary nurses (VNs) and student veterinary nurses (SVNs). This scoping review aimed to map existing evidence on this topic, and identify knowledge gaps. Methods: Literature searches of MEDLINE, PsycINFO, PubMed, Web of Science, and Google Scholar were conducted, and a structured screening and selection procedure applied. To be included, studies had to be peer-reviewed, report relevant results specific to VNs and/or SVNs, and provide descriptive statistics if using quantitative methods. Results: Of 2,118 publications identified, only 13 journal articles met the inclusion criteria. The findings were summarised in five categories: mental health and wellbeing; burnout; stress; compassion fatigue; and moral distress. While the findings of five of the studies suggested that some VNs and SVNs experienced some form of poor mental health, these lacked generalisability or transferability for multiple reasons. There was also inconsistency and ambiguity in the interpretation of findings, and incompatible or oversimplified definitions of mental health problems. Conclusions: More research is needed to address the gaps in existing evidence supporting our understanding of VN and SVN mental health. This should establish baseline measures, and include comparisons with other occupational and national populations

Socialising Big Data: From concept to practice

The working paper is a report on an ESRC-fundedproject, Socialising Big Data, that sought to address problematic conceptions of Big Data in popular discourse such as the ‘data deluge’ and the tendency to reduce the term to definitions such as the oft-cited‘3 Vs’. Instead, building on how social scientists have conceived of things, methods and data as having social and cultural lives, the project sought to identify the normative, political and technical imperatives and choices that come to shape Big Data at various momentsin its social lives. Recognising that Big Data involves distributed practices across a range of fields, the project experimentedwith collaboratories as a method for bringing together and engaging with practitioners acrossthree different domains –genomics, national statistics and waste management. In this way it explored how relations between data are also simultaneously relations between people and that it is through such relations that a shared literacyand social framework for Big Datacan be forged