Transmettre la science autrement, par le débat scientifique en classe : une investigation autour des phases de la lune.

Atelier 2 : Compétences et innovations pédagogiquesNous posons avec Weil (1949/1999), la question de la transmission de la culture pour tous, comme élément d'une société qui trouve son enracinement dans le " trésor amassé par l'espèce humaine au cours des siècles ". Adoptant un double point de vue alliant didactique professionnelle (Pastré, 2011) et didactique disciplinaire, nous considérons les conceptualisations transmises et construites selon les perspectives de Piaget et Vygotsky revisitées par Bruner (1996) et Vergnaud (1996). L'étude présentée, invite à considérer la transmission de la culture scientifique à partir de l'analyse comparée d'une situation de débat relative à l'investigation scientifique autour des phases de la lune au CM2. Nous repérerons si les élèves énoncent des conceptualisations et construisent une problématisation (Fabre, 1999 ; Villeret, 2008)

Anthropogenic Renourishment Feedback on Shorebirds: a Multispecies Bayesian Perspective

In this paper the realized niche of the Snowy Plover (Charadrius alexandrinus), a primarily resident Florida shorebird, is described as a function of the scenopoetic and bionomic variables at the nest-, landscape-, and regional-scale. We identified some possible geomorphological controls that influence nest-site selection and survival using data collected along the Florida Gulf coast. In particular we focused on the effects of beach replenishment interventions on the Snowy Plover (SP), and on the migratory Piping Plover	(PP)	(Charadrius	melodus )	and	Red	Knot	(RK)	(Calidris	canutus ).	Additionally, we investigated the potential differences between the SP breeding and wintering distributions using only regional-scale physiognomic variables and the recorded occur- rences. To quantify the relationship between past renourishment projects and shorebird species we used a Monte Carlo procedure to sample from the posterior distribution of the binomial probabilities that a region is not a nesting or a wintering ground conditional on the occurrence of a beach replenishment intervention in the same and the previous year. The results indicate that it was 2.3, 3.1, and 0.8 times more likely that a region was not a wintering ground following a year with a renourishment intervention for the SP, PP and RK respectively. For the SP it was 2.5. times more likely that a region was not a breeding ground after a renourishment event. Through a maximum entropy principle model we observed small differences in the habitat use of the SP during the breeding and the wintering season. However the habitats where RK was observed appeared quite different. While ecological niche models at the macro-scale are useful for determining habitat suitability ranges, the characterization of the species’ local niche is fundamentally important for adopting concrete multi-species management scenarios. Maintaining and creating optimal suitable habitats for SP characterized by sparse low vegetation in the foredunes areas, and uneven/low-slope beach surfaces, is the proposed conservation scenario to convert anthropic beach restorations and SP populations into a positive feedback without impacting other threatened shorebird species

Accurate masses for dispersion-supported galaxies

We derive an accurate mass estimator for dispersion-supported stellar systems and demonstrate its validity by analyzing resolved line-of-sight velocity data for globular clusters, dwarf galaxies, and elliptical galaxies. Specifically, by manipulating the spherical Jeans equation we show that the dynamical mass enclosed within the 3D deprojected half-light radius r_1/2 can be determined with only mild assumptions about the spatial variation of the stellar velocity dispersion anisotropy. We find M_1/2 = 3 \sigma_los^2 r_1/2 / G ~ 4 \sigma_los^2 R_eff / G, where \sigma_los^2 is the luminosity-weighted square of the line-of-sight velocity dispersion and R_eff is the 2D projected half-light radius. While deceptively familiar in form, this formula is not the virial theorem, which cannot be used to determine accurate masses unless the radial profile of the total mass is known a priori. We utilize this finding to show that all of the Milky Way dwarf spheroidal galaxies (MW dSphs) are consistent with having formed within a halo of mass approximately 3 x 10^9 M_sun in Lambda CDM cosmology. The faintest MW dSphs seem to have formed in dark matter halos that are at least as massive as those of the brightest MW dSphs, despite the almost five orders of magnitude spread in luminosity. We expand our analysis to the full range of observed dispersion-supported stellar systems and examine their I-band mass-to-light ratios (M/L). The M/L vs. M_1/2 relation for dispersion-supported galaxies follows a U-shape, with a broad minimum near M/L ~ 3 that spans dwarf elliptical galaxies to normal ellipticals, a steep rise to M/L ~ 3,200 for ultra-faint dSphs, and a more shallow rise to M/L ~ 800 for galaxy cluster spheroids.Comment: 20 pages, 13 figures. Accepted to MNRAS on March 27th, 201

Patient Perspectives of the Doctor-at-Home Service

Introduction. Home health care has been established as an effective model for reducing mortality in the elderly. The Doctor-at-Home Service at the Community Health Centers of Burlington (CHCB) has offered home health care to Burlington residents since January 2015. Dr. Karen Sokol, MD, alone provides care to 176 patients at their homes, including at-home palliative care. CHCB hope to expand this program by hiring more providers. Objective. To understand the impact of the Doctor-at-Home Service from the pa- tients’ perspective. Methods. A survey was administered to a cohort of eighteen patients over an 8- week period and addressed topics such as barriers to healthcare, benefits, and costs associated with doctor-at-home programs. A theme analysis on the responses was then conducted to reflect patient opinions. Available summary data describing the pa- tient population was also analyzed. Results. The Doctor- at- Home program serves patients ranging from 26 to 100 years old, with the majority of the patient population comprised of senior citizens. Prior to at home care, patients faced barriers such as lack of transportation, negative past experi- ences, anxiety, and distance from relatives. Four main themes from patient responses were physician-patient relationship, convenience, quality of care, and environment of care. Discussion. Evidence is compelling that there is a desire and need for an exten- sion of the Doctor-at-Home program to reach additional patients. Doctor-at-Home pro- grams could eliminate identified barriers and provide quality care to patients, especially those with specific barriers to access.https://scholarworks.uvm.edu/comphp_gallery/1256/thumbnail.jp

SE FORMER À PRÉPARER SA CLASSE AU TRAVERS D'UN SYSTÈME D'INSTRUMENTS

International audienceComment les enseignants expérimentés du cycle 3 anticipent-ils la contingence et les aléas générés par l'environnement dynamique ouvert qu'est la classe (Rogalski, 2003) ? L'analyse d'entretiens d'explicitation menés auprès de cinq d'entre eux nous mène à envisager l'activité de préparation de classe à travers la construction et l'utilisation d'un système d'instruments (Rabardel, 1995 ; Bourmaud, 2006, 2007 ; Munoz et Bourmaud, 2011) composé des programmations, des fiches de préparation et du cahier-journal. Nous identifions certaines des conceptualisations-en-acte (Vergnaud, 1996) qu'ils ont construits dans l'expérience pour cibler leur activité dans des visées à court, moyen et long terme afin de s'adapter aux besoins des élèves en situation. De ces résultats d'analyse, nous esquissons une proposition d'atelier de formation à destination des débutants

Une analyse de l'activité de planification des enseignants : vers la conception d'instruments

International audienceNos recherches avaient pour but a priori de déterminer quelles étaient les compétences développées par les enseignants expérimentés de cycle 3 dans leur activité de planification ou de préparation. Nos résultats nous orientent vers la question de la conception d'instruments (Rabardel, 1995) qui leur permettent de gérer le caractère dynamique ouvert de la situation de classe (Rogalski, 2003). Les cadres de la didactique professionnelle (Pastré, 2011) et de la psychologie ergonomique (Leplat, 2006 ; Goigoux, 2007) nous ont permis de comprendre comment, à partir des concepts-en-actes issus de l'expérience, (Vergnaud, 1996) montrés par notre analyse, les enseignants mettent en œuvre des stratégies et tactiques à échelles temporelles variées pour assurer leur mission. C’est là l'opportunité de discuter le contenu de la formation initiale reçue, qui selon leurs propos, semble faire défaut en la matière.Type de communication Compte-rendu de recherche dans le cadre d'un mémoire de master 1 Sciences de l'Éducation Thématique principale Thème 3 : Place et rôle de la conception dans l'activité du formateur Résumé Nos recherches avaient pour but a priori de déterminer quelles étaient les compétences développées par les enseignants expérimentés de cycle 3 dans leur activité de planification ou de préparation. Nos résultats nous orientent vers la question de la conception d'instruments (Rabardel, 1995) qui leur permettent de gérer le caractère dynamique ouvert de la situation de classe (Rogalski, 2003). Les cadres de la didactique professionnelle (Pastré, 2011) et de la psychologie ergonomique (Leplat, 2006 ; Goigoux, 2007) nous ont permis de comprendre comment, à partir des concepts-en-actes issus de l'expérience, (Vergnaud, 1996) montrés par notre analyse, les enseignants mettent en oeuvre des stratégies et tactiques à échelles temporelles variées pour assurer leur mission. C'est là l'opportunité de discuter le contenu de la formation initiale reçue, qui selon leurs propos, semble faire défaut en la matière. Mots-Clés Enseignant, préparation/planification, instrument, schèmes de conception

The Impact of Overstocking and Negative Energy Balance on Quantitative Measurement of Non-typhoidal Salmonella in Periparturient Dairy Cattle

Stressful conditions in animal production facilities may exacerbate the fecal shedding and foodborne transmission of non-typhoidal Salmonella enterica subsp. enterica. Dairy cows are reservoirs of this zoonotic microorganism, and its prevalence has roughly doubled in the past decade on dairy farms in United States. Dairy cows are commonly overstocked at the feed bunk, and stressors placed on the animal prior to parturition may exacerbate Salmonella shedding. However, no studies have evaluated the impact of overstocking and metabolic stress on fecal concentrations of the pathogen. Therefore, we conducted a field trial with 120 multiparous dairy cows randomized into one of four treatment groups with different stocking densities at the feed bunk during the periparturient period as follows: US, understocked from -60 to -1 DRC; OS, overstocked from -60 to -1 DRC; USOS, understocked from -60 to -26 DRC/overstocked from -25 to -1 DRC; and OSUS, overstocked from -60 to -26 DRC/ understocked from -25 to -1 DRC. Fecal and blood samples were collected at four time points relative to calving. qPCR assays were used to quantify Salmonella invA gene and total bacterial community from fecal samples, and a subset of isolates recovered from fecal bacterial culture were characterized using pulsed field gel electrophoresis and serotyping. Serum non-esterified fatty acids (NEFA) were measured as a metabolic stress indicator using an immunoassay. Multivariable analyses were performed to test if changes in Salmonella concentrations were associated with stocking density, energy balance, or days relative to calving. From fecal isolates, three Salmonella serovars were identified, S. Cerro; Kentucky; Meleagridis. Concentrations of Salmonella increased as cows approached calving. Higher stocking densities at the feed bunk did not impact total bacterial community or NEFA; however, cows in the overstocked groups had higher Salmonella fecal concentrations. Further, cows with higher NEFA concentrations after calving had a higher likelihood of detection of Salmonella. Future farm interventions should aim to reduce environmental and metabolic stress during the periparturient period to decrease the dissemination of Salmonella to cattle, the environment, and humans.Peer reviewe