The stochastic background from cosmic (super)strings: popcorn and (Gaussian) continuous regimes

In the era of the next generation of gravitational wave experiments a stochastic background from cusps of cosmic (super)strings is expected to be probed and, if not detected, to be significantly constrained. A popcorn-like background can be, for part of the parameter space, as pronounced as the (Gaussian) continuous contribution from unresolved sources that overlap in frequency and time. We study both contributions from unresolved cosmic string cusps over a range of frequencies relevant to ground based interferometers, such as LIGO/Virgo second generation (AdLV) and Einstein Telescope (ET) third generation detectors, the space antenna LISA and Pulsar Timing Arrays (PTA). We compute the sensitivity (at $2 \sigma$ level) in the parameter space for AdLV, ET, LISA and PTA. We conclude that the popcorn regime is complementary to the continuous background. Its detection could therefore enhance confidence in a stochastic background detection and possibly help determine fundamental string parameters such as the string tension and the reconnection probability.Comment: 21 pages, 11 figures ; revised version after correction of a typo in eq. 4.

Parents et enseignants en contexte de diversité culturelle: quelle négociation des rôles ?: Inégalités et tensions de rôles autour de la "normalisation" des pratiques parentales

Le travail de thèse présenté dans cet ouvrage a été réalisé dans le cadre du projet de recherche COREL1 (1 Projet de recherche n° 152695 « COREL : Quand l’enfant devient élève, et les parents, parents d’élèves. Construction de la relation entre les familles et l’école lors de l’entrée à l’école », soutenu par le Fonds National Suisse de la recherche scientifique (FNS) et dirigé par la Prof. Tania Ogay du département des sciences de l’éducation de l’Université de Fribourg), soutenu par le Fonds National Suisse de la recherche scientifique (FNS). L’objectif de la recherche COREL était de saisir le processus de construction de la relation entre l’école et les familles au moment de l’entrée à l’école de l’enfant aîné, dans un établissement scolaire accueillant majoritairement des enfants de familles issues de la migration et/ou disposant de revenus modestes. La qualité de la relation familles-école est aujourd’hui établie comme un élément contributeur essentiel de la réussite scolaire de l’enfant (Patrikakou, Weissberg, Redding, & Walberg, 2005). Préoccupés par les inégalités persistantes, les systèmes scolaires et plus largement éducatifs appellent instamment l’école et les familles à oeuvrer dans une relation de partenariat (Pithon, Asdih, & Larivée, 2008), dans un objectif d’égalisation des chances scolaires. Pourtant, au-delà des discours institutionnels, la manière dont l’appel au partenariat familles-école se concrétise dans les pratiques interroge. Tel qu’appréhendé par les acteurs scolaires, il tend à surtout accroître la connivence entre l’école et les parents proches de la culture scolaire (Payet & Giuliani, 2014), et à paradoxalement renforcer la distance entre l’école et les parents qui en sont peu familiers (Périer, 2005). La question du partenariat familles-école renvoie à un objet central, celui de la négociation des rôles entre parents et enseignants. Pourtant, peu de chercheurs traitent explicitement de cet objet, encore moins dans une approche communicationnelle, alors même que la communication se trouve au coeur de la construction de la relation familles-école (Ogay & Cettou, 2014). Notre travail de thèse s’est inscrit dans ce constat. Ancré dans une perspective de communication interculturelle (Frame, 2013), il a eu pour objectif d’investiguer, dans le cadre du projet COREL, la manière dont parents et enseignants négocient leurs rôles au coeur de leurs interactions, dans une approche de la négociation des rôles héritée du courant de l’interactionnisme symbolique (Blumer, 1969 ; Strauss, 1992). La démarche ethnographique de la recherche COREL, en croisant comme outils de collecte l’observation des interactions entre parents et enseignants, la conduite d’entretiens semi-dirigés avec les acteurs, et la récolte de documents, couplée à la méthodologie d’analyse inductive adoptée dans le cadre de notre travail de thèse, nous ont permis de dégager une compréhension fine de ce processus de négociation des rôles, dont les résultats ont été présentés sous la forme des quatre publications constituant le coeur de cette thèse cumulative. Dans la perspective de communication interculturelle qui est la nôtre, ces résultats nous amènent à relever comment la négociation des rôles entre parents et enseignants, dans un contexte de diversité culturelle comme celui du terrain de la recherche COREL, peut se trouver prise dans une dynamique de ‘normalisation’ institutionnalisée du rôle parental vis-à-vis d’une norme scolaire toute-puissante, caractéristique d’un ethnocentrisme institutionnel qui tend à imprégner l’école et ses acteurs (Asdih, 2012 ; Ogay, 2017a). Cet ethnocentrisme se manifeste par l’imposition d’une norme scolaire vue comme allant de soi et indiscutable, mais également par l’entretien d’implicites au sujet de cette norme scolaire, créateurs de malentendus avec les parents peu familiers du monde scolaire. Dans un tel contexte, la négociation des rôles entre parents et enseignants se caractérise par des tensions de rôles difficilement solubles pour les acteurs, entre des forces contradictoires appelant au partenariat d’une part, à la mise en conformité des pratiques éducatives parentales d’autre part. Nous rejoignons Dubet (1997) et Périer (2005) quant au fait qu’une négociation des rôles réellement partenariale avec les parents dans leur diversité, qui soit empreinte d’équité et au final mieux vécue par les parents minoritaires comme par les enseignants, exige que l’école et les enseignants développent une logique de reconnaissance et de participation du parent réel. Nous soulignons toutefois que cette reconnaissance ne peut se faire à nos yeux sans que l’école et les enseignants ne s’engagent simultanément dans une démarche de décentration et de remise en question de la relation de pouvoir qui existe entre l’école et les familles, particulièrement les familles minoritaires

Les ethnothéories de l'éducation, quel accord entre parents migrants et enseignantes?

International audienceEn prologue à une recherche portant sur la construction de la relation familles-école au moment de l'entrée à l'école, nous présentons ici les résultats d'une recherche préliminaire, descriptive et quantitative, dont l'objectif est de comparer parents migrants et enseignants du point de vue de leurs conceptions (ou " ethnothéories " selon le modèle de la niche développementale) de l'éducation et du développement de l'enfant. L'enquête a été réalisée au moyen d'un questionnaire auquel ont répondu 31 enseignantes de l'école enfantine, 27 parents migrants portugais et 22 parents migrants africains, tous résidant à Fribourg (Suisse). Si les résultats témoignent de différences intergroupes, ils montrent surtout une divergence entre les parents et les enseignantes, ce qui interroge par rapport à une relation de partenariat souvent présentée comme allant de soi

Preparation of mono-substituted malonic acid half oxyesters (SMAHOs).

The use of mono-substituted malonic acid half oxyesters (SMAHOs) has been hampered by the sporadic references describing their preparation. An evaluation of different approaches has been achieved, allowing to define the best strategies to introduce diversity on both the malonic position and the ester function. A classical alkylation step of a malonate by an alkyl halide followed by a monosaponification gave access to reagents bearing different substituents at the malonic position, including functionalized derivatives. On the other hand, the development of a monoesterification step of a substituted malonic acid derivative proved to be the best entry for diversity at the ester function, rather than the use of an intermediate Meldrum acid. Both these transformations are characterized by their simplicity and efficiency, allowing a straightforward access to SMAHOs from cheap starting materials

Ionic Species Affect the Self-Propulsion of Urease-Powered Micromotors

Enzyme-powered motors self-propel through the catalysis of in situ bioavailable fuels, which makes them excellent candidates for biomedical applications. However, fundamental issues like their motion in biological fluids and the understanding of the propulsion mechanism are critical aspects to be tackled before a future application in biomedicine. Herein, we investigated the physicochemical effects of ionic species on the self-propulsion of urease-powered micromotors. Results showed that the presence of PBS, NaOH, NaCl, and HEPES reduced self-propulsion of urease-powered micromotors pointing towards ion-dependent mechanisms of motion. We studied the 3D motion of urease micromotors using digital holographic microscopy to rule out any motor-surface interaction as the cause of motion decay when salts are present in the media. In order to protect and minimize the negative effect of ionic species on micromotors' performance, we coated the motors with methoxypolyethylene glycol amine (mPEG) showing higher speed compared to noncoated motors at intermediate ionic concentrations. These results provide new insights into the mechanism of urease-powered micromotors, study the effect of ionic media, and contribute with potential solutions to mitigate the reduction of mobility of enzyme-powered micromotors

Goal-oriented behavioural and environmental enrichment in aquarium species

Environmental enrichment is a common tool used in zoo and aquarium settings to provide mental and physical stimulation to animals under human care. This paper aims to present a primary approach to goal-oriented environmental and behavioural enrichment following a simplified version of the SPIDER method for a diverse range of aquarium-housed species. The aim of the proposed goal-oriented environmental-enrichment programme is to stimulate behavioural diversity by providing controlled stimuli. This programme is easy to implement and can be used by animal care staff; it encompasses an easy evaluation form for daily monitoring and seeks to increase species-specific behavioural diversity. It is suggested that environmental enrichment programmes should be designed for the benefit of animal welfare; understanding how they affect animals under human care is essential to take informed decisions about which behaviours or situations to stimulate. An environmental enrichment protocol was developed which considers the ethology and biology of the species under consideration prior to implementation. Specific goals (i.e., behaviours and/or actions) were assigned to particular stimuli (enrichment devices) and the efficacy of the enrichment devices were assessed by reporting on the reactions of the animals. Over time, this protocol has made it possible to define a validated catalogue of enrichment devices for which specific goals and expected reactions are consistent. The increased behavioural diversity achieved with this programme is providing aquatic species with the choice to display species-specific behaviours

Stable isotope analysis of dietary arginine accrual and disposal efficiency in male rats fed diets with different protein content.

The administration of diets with different protein/energy ratios induce variable but distinctive responses in rats; an excessive protein content tends to decrease fat accumulation, but reversion of this ratio tends to increase adipose tissue mass. The fate of N derived from amino acid metabolism is not only dependent on energy and dietary protein; the increased excretion of urea elicited by high-protein diets contrasts with the lower urea excretion (despite excess dietary protein and energy) in rats fed a cafeteria diet. After one month of exposure to high-protein (HPD) or cafeteria (CD) diets, we administered a gavage of 15N-arginine to undisturbed adult male rats, in order to trace the utilization of this not-recyclable-N amino acid under diets with different protein/energy relationships. Rats fed high-protein diet excreted higher amounts of N in urine and showed much lower gastrointestinal content of label. The CD rats decreased the excretion of urine N. Both groups' N balance showed a significant proportion of N not-accounted-for (but excreted nevertheless), the proportion being especially large in the HPD group. In conclusion, the process of disposal of amino acid N through the so far unknown pathway for 'non-accounted-for N' is, thus essentially dependent on excess amino acid availability; independently of urea cycle operation and diet energy content

Evolução como princípio organizador em cordados: uma experiência no ensino médio a partir do PIBID/UEM

Anais do II Seminário Seminário Estadual PIBID do Paraná: tecendo saberes / organizado por Dulcyene Maria Ribeiro e Catarina Costa Fernandes — Foz do Iguaçu: Unioeste; Unila, 2014Pesquisadores e documentos normativos da Educação Básica de Ensino têm ressaltado a necessidade de se trabalhar a disciplina Biologia em sala de aula tendo como eixo articulador e organizador a Evolução Biológica. Frente a esta premissa, foi elaborada, por licenciandos do curso de Ciências Biológicas, integrantes do Programa Institucional de Bolsas de Iniciação à Docência (PIBID) da Universidade Estadual de Maringá, uma Sequência Didática para o ensino do Phylum Chordata, desenvolvida junto a uma turma do segundo ano do Ensino Médio, de uma escola pública de Maringá, região noroeste do Paraná/Brasil. Os resultados evidenciaram que essa forma de organização do ensino favoreceu o entendimento das diferenças e similaridades existentes nos diferentes grupos de cordados como resultado dos complexos mecanismos evolutivos, que atuaram, atuam e atuarão ao longo da história evolutiva, possibilitando tamanha diversidad

Self-Propulsion of Active Colloids via Ion Release: Theory and Experiments

We study the self-propulsion of a charged colloidal particle that releases ionic species using theory and experiments. We relax the assumptions of thin Debye length and weak nonequilibrium effects assumed in classical phoretic models. This leads to a number of unexpected features that cannot be rationalized considering the classic phoretic framework: an active particle can reverse the direction of motion by increasing the rate of ion release and can propel even with zero surface charge. Our theory predicts that there are optimal conditions for self-propulsion and a novel regime in which the velocity is insensitive to the background electrolyte concentration. The theoretical results quantitatively capture the salt-dependent velocity measured in our experiments using active colloids that propel by decomposing urea via a surface enzymatic reaction

Cuidados de higiene oral ao utente intubado orotraquealmente: Fatores influenciadores. Revisão sistemática da literatura

Aims: Identify factors that interfere in the provision of oral hygiene care, developed by nurses, to orotracheally intubated patients in intensive care units, on primary scientific evidence.Methods: A systematic literature review study, developed according to the Joanna Briggs Institute protocol. To obtain the articles, a search on B-On and PubMed was made. The terms used in the search took into account the vocabulary indexed to the Medical Subject Headings (MeSH) database, having been structured according to Boolean operators, with the following combination in English: “Oral Hygiene” AND “Pneumonia, Ventilator-Associated” OR “Pneumonia, Ventilator Associated” AND “Critical Care Nursing”. Articles published between December 2017 and December 2020, in English, Portuguese and Spanish, available in full, published in peer-reviewed scientific journals (peer review) and which fit the PICO question developed for the study, were defined as limiting.Results: After applying the inclusion and exclusion criteria, eight articles of a primary and qualitative nature were included in the review that address the factors that influence the provision of oral hygiene care by nurses to patients undergoing orotracheal intubation.Conclusions: The oral hygiene care practices provided to users under orotracheal intubation, by nurses, are influenced by their knowledge, attitudes, available resources, training and institutional policies, as well as by factors related to the user that are mainly related to difficulties in access to the oral cavity.  Objetivos: Identificar evidencias científicas primarias sobre los principales factores que interfieren en la prestación de cuidados de higiene bucal, desarrollados por enfermeros, a usuarios intubados orotraquealmente en unidades de cuidados intensivos.Método: Estudio de revisión sistemática de la literatura, desarrollado según el protocolo del Instituto Joanna Briggs. Para la obtención de los artículos se utilizaron los motores de búsqueda B-On y PubMed. Los términos utilizados en la búsqueda tuvieron en cuenta el vocabulario indexado a la base de datos Medical Subject Headings (MeSH), habiéndose estructurado según operadores booleanos, con la siguiente combinación, en inglés: “Oral Hygiene” AND “Pneumonia, Ventilator-Associated” OR “Pneumonia, Ventilator Associated” Y “Critical Care Nursing”. Se definieron como limitantes artículos publicados entre diciembre de 2017 y diciembre de 2020, en inglés, portugués y español, disponibles en su totalidad, publicados en revistas científicas revisadas por pares (peer review) y que se ajustan a la pregunta PICO desarrollada para el estudio.Resultados: Después de aplicar los criterios de inclusión y exclusión, se incluyeron en la revisión ocho artículos de carácter primario y cualitativo que abordan los factores que influyen en la prestación de cuidados de higiene bucal por parte de los enfermeros a pacientes sometidos a intubación orotraqueal.Conclusión: Las prácticas de cuidado de la higiene bucal brindadas a los usuarios en intubación orotraqueal, por parte de los enfermeros, son influenciadas por sus conocimientos, actitudes, recursos disponibles, capacitación y políticas institucionales, así como por factores relacionados al usuario que se relacionan principalmente con las dificultades de acceso a la cavidad oral.Objetivo: Identificar evidências científicas primárias sobre os principais fatores que interferem na prestação de cuidados de higiene oral, desenvolvidos pelos enfermeiros, aos utentes intubados orotraquealmente, nas unidades de cuidados intensivos.Métodos: Estudo de revisão sistemática da literatura, desenvolvido segundo o protocolo do The Joanna Briggs Insitute. Para a obtenção dos artigos recorreu-se aos motores de busca B-On e PubMed. Os termos utilizados na pesquisa tiveram em consideração o vocabulário indexado à base de dados Medical Subject Headings (MeSH), tendo sido estruturada segundo os operadores boleanos, com a seguinte combinação em inglês: “Oral Hygiene” AND “Pneumonia, Ventilator-Associated” OR “Pneumonia, Ventilator Associated” AND “Critical Care Nursing”. Foram definidos como limitadores, artigos publicados entre dezembro de 2017 e dezembro de 2020, em Inglês, Português e Espanhol, disponíveis na íntegra, publicados em revistas científicas revistas por pares (peer review) e que se enquadrassem na pergunta PICO desenvolvida para o estudo. Resultados: Após a aplicação dos critérios de inclusão e exclusão, foram incluídos na revisão oito artigos de natureza primária e qualitativa que abordam os fatores que influenciam a prestação de cuidados de higiene oral, pelos enfermeiros, aos utentes sob intubação orotraqueal. Conclusões: As práticas de cuidados de higiene oral prestadas aos utentes sob intubação orotraqueal, pelos enfermeiros, são influenciadas pelo seu conhecimento, atitudes, recursos disponibilizados, treino e políticas institucionais, bem como por fatores relacionados com o utente que se prendem, maioritariamente, com dificuldades de acesso à cavidade ora