J. Guichard, & M., Huteau. Psychologie de l’orientation.

Le Code de déontologie des psychologues énonce dans son titre I sept principes qui fondent l'action des praticiens. Le deuxième d'entre eux précise que « le psychologue tient ses compétences de connaissances théoriques régulièrement à jour ». Le livre de Jean Guichard et Michel Huteau répond à cette obligation. En ce début de millénaire, tous ceux qui ont, ou qui auront, à se préoccuper des parcours de vie des individus peuvent trouver ici les fondements de leurs pratiques. Les auteurs tirent..

La liberté académique

This book analyses the threats to academic freedom in the twenty-first century across the globe, and the various ways to face them

Soil exploration and resource acquisition by plant roots: an architectural and modelling point of view

We provide a brief overview on soil exploration and resource extraction by roots during the course of plant development. First, we examine how roots explore the soil volume in relation with the heterogeneity of soil conditions. We then consider resource acquisition by roots and root systems, taking into account the root system's heterogeneous functioning and its variable degree of plasticity. In extensive, complex and dynamic systems such as root systems, processes of soil exploration and resource acquisition can be analysed through the unifying point of view of root system architecture. We exemplify how a modelling approach based on the concepts of functional architecture has potential to provide sharper insight into the soil exploration/utilization processes.Exploration du sol et acquisition des ressources hydro-minérales par les systèmes racinaires des végétaux : un point de vue architectural et de modélisation. Nous présentons une courte revue décrivant les grandes étapes de colonisation et d'exploitation du sol durant le développement de la plante. Nous montrons tout d'abord comment les racines explorent le sol en interagissant avec l'hétérogénéité des conditions de sol (du point de vue des nutriments ou des contraintes à la croissance). De cette vision essentiellement géométrique (exploration), nous passerons à l'exploitation des ressources par les racines en considérant l'hétérogénéité de fonctionnement du système racinaire ainsi que son plus ou moins fort degré de plasticité. Ces processus d'exploration et d'exploitation du sol seront présentés sous l'angle unificateur de la prise en compte de l'architecture racinaire. Dans des systèmes complexes et très dynamiques, comme un système racinaire, nous montrerons, avec des exemples récents, comment la modélisation, fondée sur une architecture fonctionnelle, permet d'aller plus loin dans la compréhension des processus d'exploration/exploitation du sol par les plantes

Observing plant roots in their environment: current imaging options and specific contribution of two-dimensional approaches

This paper provides an overview of current options for imaging roots in their environment. Our primary aim is to describe the potential and limitations of these techniques, rather than their physical principles. We primarily discuss two-dimensional imaging techniques which, while inherently limited by their 2-dimensional nature are technically simple, cheaper, more readily accessible, and offer larger field- of-view or better resolution for a similar field-of-view than three-dimensional imaging techniques. We show that techniques involving microscopic or high-resolution X-ray imaging of roots in undisturbed soil samples have a considerable value because they can provide, at a scale which is not accessible by any other means, essential information on complex interactions between roots and soil structure. We also illustrate how 2D imaging techniques, based on either visible light or X-ray attenuation through thin growing containers (rhizotrons), can be used to study whole root systems. We conclude that, while fully appropriate 3D imaging tools will ultimately become available, in the meantime, two-dimensional techniques should be considered as relevant options for observing roots in their environment.Observation des racines dans leur environnement : techniques d'imagerie actuelles et apports spécifiques des approches 2D. Cet article offre un inventaire des techniques d'imagerie actuellement disponibles pour l'observation des racines au sein de leur environnement. Le propos est avant tout d'informer le lecteur sur le potentiel et les limites des techniques et non sur leurs principes physiques. D'autre part, l'accent est mis sur l'apport spécifique des méthodes 2D : en dépit des limitations et biais qui leur sont inhérents, ces méthodes offrent en effet, par rapport aux outils 3D actuellement disponibles, des avantages tels qu'un grand champ d'observation ou une résolution supérieure à champ d'observation équivalent, ou encore, une mise en œuvre simplifiée et un coût réduit. Ainsi, la microscopie et la radiographie X à haute résolution sont très attractives car elles permettent d'étudier, à une échelle qui demeure hors de la portée des méthodes 3D, les interactions complexes entre racines et structure du sol. On montre par ailleurs que les méthodes 2D basées sur l'atténuation de lumière visible ou de rayons X s'avèrent très utiles pour étudier le fonctionnement de systèmes racinaires entiers en rhizotrons. S'il ne fait guère de doute qu'à relativement court terme, les progrès accomplis dans le domaine de l'imagerie 3D aboutiront à la mise au point d'outils parfaitement adaptés à l'observation non destructive des racines dans leur environnement, il n'en reste pas moins que, dans l'attente de tels outils, les techniques 2D continueront de faire progresser notre connaissance des racines et de leur fonctionnement

Estimating root elongation rates from morphological measurements of the root tip

To measure the elongation rate of individual roots in soil remains a challenge. A novel method for estimating elongation rates of excavated roots is presented. Morphological markers are identified along the tip of excavated roots, and their distance relative to the apex is measured. These markers correspond to developmental stages which follow known temporal patterns. Hence, their distance relative to the apex reflects root elongation during the period corresponding to their development. The method was tested on maize roots grown in a range of conditions and substrates. It was found that distances from markers to apices were proportional, with some variability, to elongation rates. Remarkably, the linear relationships between these distances were neither affected by substrate, nor by growing conditions. Using several markers allows covering time periods ranging from 0.3 day to 3 days as well as cross validation of estimates. Provided further testing, under a wider range of environmental conditions, is conducted, the concepts presented in this paper may serve to define a new measurement technique

A soil column model for predicting the interaction between water table and evapotranspiration

International audienceLateral waterfluxes are not realistically taken into account in soil column models, although they influence the dynamic evolution of the vertical soil moisture profile. By neglecting these fluxes, the modeling of the soil‐vegetation‐atmosphere continuum is incomplete, and the feedbacks between these three compartments cannot be fully simulated. These fluxes have an importance in the different fields where soil column models are used: hydrology, hydrometeorology, biogeochemical cycles, ecology, and soil weathering. This paper introduces a novel Hydrological Hillslope‐based Soil Column model (H2SC) that simulates the temporal evolution of the water table depth and evapotranspiration fluxes and their interaction. The interconnected processes are infiltration, evapotranspiration, vertical soil water movements, and the nonexplicitly modeled lateral fluxes flowing through the soil column. These lateral fluxes are modeled as a drainage function built from physically based equations that describe a simplified hillslope hydrology. This drainage function can be easily implemented in any soil column model without penalizing computational times. The H2SC model was validated on numerical experiments where a 2‐D hillslope simulation performed with an integrated hydrologic model was compared with simulations using the H2SC 1‐D model. Each of the H2SC simulations represents a specific location of a soil column along the hillslope. Different climate forcings, soil properties, and geometric shapes of the hillslope were tested. The model was then applied at the locations of two piezometers in the Strengbach catchment, France. The model reproduced the temporal evolution of the water table level fairly well for both the numerical experiments and for the real test case

The dramatic increase in the rate of methylisothiazolinone contact allergy in Belgium: a multicentre study

BACKGROUND: The rate of contact allergy and allergic contact dermatitis caused by methylisothiazolinone (MI) is dramatically increasing throughout Europe. OBJECTIVES: To report on methylchloroisothiazolinone (MCI)/MI and MI allergy in Belgium. PATIENTS AND METHODS: Between January 2010 and December 2012, the medical charts of 6599 patients of the Belgian Contact and Environmental Dermatitis Group were retrospectively reviewed for MCI/MI and MI sensitization by use of a standardized questionnaire. Available data on sensitization in 2081 patients tested in 2013 were also included. RESULTS: In 2012, the sensitization rate for MCI/MI had increased to 4.5% and that for MI to 6.0%; the latter showed a further increase to 7.2% in 2013. The people mainly affected were women with a median age of 49 years with hand and/or facial dermatitis, most often resulting from the use of cosmetics. Simultaneous reactions to octylisothiazolinone were observed. CONCLUSION: A dramatic increase in the rate of contact allergy caused by MI in cosmetics is occurring in Belgium. Notwithstanding the recent recommendation to discontinue the use of MI in leave-on cosmetics, safer use concentrations should also be determined for rinse-off products. Close monitoring of MI sensitization in the near future will be necessary, and the highest test concentrations reported for MI and MCI/MI should be included in the baseline series.status: publishe

Soil priorities: Opportunities and challenges in Thailand

International audienc

Conventional detection methodology is limiting our ability to understand the roles and functions of fine roots

We lack a thorough conceptual and functional understanding of fine roots. Studies that have focused on estimating the quantity of fine roots provide evidence that they dominate overall plant root length. We need a standard procedure to quantify root length/biomass that takes proper account of fine roots. Here we investigated the extent to which root length/biomass may be underestimated using conventional methodology, and examined the technical reasons that could explain such underestimation. Our discussion is based on original X-ray-based measurements and on a literature review spanning more than six decades. We present evidence that root-length recovery depends strongly on the observation scale/spatial resolution at which measurements are carried out; and that observation scales/resolutions adequate for fine root detection have an adverse impact on the processing times required to obtain precise estimates. We conclude that fine roots are the major component of root systems of most (if not all) annual and perennial plants. Hence plant root systems could be much longer, and probably include more biomass, than is widely accepted

La construction de la famille juive : Entre héritage et devenir

Des documents araméens d’Éléphantine dans l’Égypte du viie siècle avant l’ère chrétienne aux enquêtes ethnologiques du xxie siècle sur les juifs éthiopiens en Israël, cet ouvrage présente des problématiques his­toriques, ethnologiques, linguistiques et anthropologiques sur la famille juive à différentes époques, dans les espaces où les juifs ont su fonder des cultures originales. Comment les sociétés juives ont-elles adapté l’arsenal juridique hérité de la Bible et du Talmud relatif au mariage, au divorce, au lévirat ou à l’héritage des filles? Quelle mission éducative relève de la famille? Quel est le rôle de cette dernière dans la transmission de valeurs, rites et coutumes qui fondent l’appartenance ou l’identité? Quelles images apparaissent à l’écran, au théâtre ou encore à travers les stéréotypes de l’épigraphie funéraire ? La construction de la famille s’appuie-t-elle sur les représentations et modèles de parenté engrangés dans une mémoire collective et individuelle ? Ce livre, issu de la collaboration de quinze chercheurs spécialistes des études juives, s’efforce de répondre à ces questions avec clarté et érudition