274 research outputs found

    BD2I : Normes sur l'identification de 274 images d'objets et leur mise en relation chez l'enfant français de 3 à 8 ans

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    The data base BD2I provides the first French norms for children of 274 pictures of objects (150 from Snodgarss and Vanderwart, 1980). Correct picture identification and naming, and identification of taxonomic and thematic associations were evaluated between 3 and 8 years. Verbal justification and strength of the associations were assessed between 4 and 8 years. All norms were collected from 80 children by age. Visual similarity was judged by 40 adults. These normative data are necessary because children are less efficient than adults in naming and also because their representations of objects relations differ from those of adults

    Weed flora in rice areas under distinct cropping systems, herbicide and irrigation managements

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    We aimed to evaluate the incidence of weeds in the pre-planting of the summer crop as a function of planting system, herbicide use and irrigation management. The experiment was installed in field conditions, in RBD and 3 x 2 factorial scheme with eight replications. Treatments consisted in submitting rice to three management factors: water management – continuously flooded or intermittend irrigation (Factor A), coupled to the application (traditional control) or not (semi-ecological system) of herbicides (Factor B), and planting system – conventional soil tillage, minimum tillage and no till systems (Factor C). One year after rice cultivation, preceding the planting of the next cropping season, phytosociological evaluations of the weed communities were carried out. We assessed the overall infestation and weed species composition, which were classified by their respective density, frequency and dominance. We also estimated the diversity coefficients of Simpson and Shannon Weiner, and the sustainability coefficient of Shannon; treatments were also grouped by similarity in weed composition. In flood-irrigated rice, no till provides the lowest levels of weed infestation and, together with the conventional cropping system, results in values closer to the ecological sustainability; The application of herbicides in flooded rice crops reduces weed infestation, increases diversity and equalizes the ecological sustainability, compared to areas without the application of weed management methods. However, chemical control leads to the selection of resistant or tolerant species to herbicides, such as Polypogon sp.; Both continuous and intermittent water management systems did not cause changes in the level of infestation, composition or diversity coefficients

    Incidence, scaling relations and physical conditions of ionized gas outflows in MaNGA

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    In this work, we investigate the strength and impact of ionised gas outflows within z∌0.04z \sim 0.04 MaNGA galaxies. We find evidence for outflows in 322 galaxies (12%12\% of the analysed line-emitting sample), 185 of which show evidence for AGN activity. Most outflows are centrally concentrated with a spatial extent that scales sublinearly with ReR_{\rm e}. The incidence of outflows is enhanced at higher masses, central surface densities and deeper gravitational potentials, as well as at higher SFR and AGN luminosity. We quantify strong correlations between mass outflow rates and the mechanical drivers of the outflow of the form M˙out∝SFR0.97\dot{M}_{\rm out} \propto \rm SFR^{0.97} and M˙out∝LAGN0.55\dot{M}_{\rm out} \propto L_{\rm AGN}^{0.55}. We derive a master scaling relation describing the mass outflow rate of ionised gas as a function of M⋆M_{\star}, SFR, ReR_{\rm e} and LAGNL_{\rm AGN}. Most of the observed winds are anticipated to act as galactic fountains, with the fraction of galaxies with escaping winds increasing with decreasing potential well depth. We further investigate the physical properties of the outflowing gas finding evidence for enhanced attenuation in the outflow, possibly due to metal-enriched winds, and higher excitation compared to the gas in the galactic disk. Given that the majority of previous studies have focused on more extreme systems with higher SFRs and/or more luminous AGN, our study provides a unique view of the non-gravitational gaseous motions within `typical' galaxies in the low-redshift Universe, where low-luminosity AGN and star formation contribute jointly to the observed outflow phenomenology.Comment: Accepted for publication in MNRAS, 27 pages, Fig 7 & 8 for scaling wind strength with drivers, Fig 10 for master scalin

    Cool outflows in MaNGA:a systematic study and comparison to the warm phase

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    This paper investigates the neutral gas phase of galactic winds via the Na I Dλλ5890,5895\lambda\lambda 5890,5895{\AA} feature within z∌0.04z \sim 0.04 MaNGA galaxies, and directly compares their incidence and strength to the ionized winds detected within the same parent sample. We find evidence for neutral outflows in 127 galaxies (∌5\sim 5 per cent of the analysed line-emitting sample). Na I D winds are preferentially seen in galaxies with dustier central regions and both wind phases are more often found in systems with elevated SFR surface densities, especially when there has been a recent upturn in the star formation activity according to the SFR5Myr_{5Myr}/SFR800Myr_{800Myr} parameter. We find the ionized outflow kinematics to be in line with what we measure in the neutral phase. This demonstrates that, despite their small contributions to the total outflow mass budget, there is value to collecting empirical measurements of the ionized wind phase to provide information on the bulk motion in the outflow. Depending on dust corrections applied to the ionized gas diagnostics, the neutral phase has ∌1.2−1.8\sim 1.2 - 1.8 dex higher mass outflow rates (M˙out\dot{M}_{out}), on average, compared to the ionized phase. We quantify scaling relations between M˙out\dot{M}_{out} and the strengths of the physical wind drivers (SFR, LAGNL_{AGN}). Using a radial-azimuthal stacking method, and by considering inclination dependencies, we find results consistent with biconical outflows orthogonal to the disk plane. Our work complements other multi-phase outflow studies in the literature which consider smaller samples, more extreme objects, or proceed via stacking of larger samples.Comment: This is a pre-copyedited, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society (MNRAS) following peer revie

    O TRABALHO PEDAGÓGICO SOBRE A TEMÁTICA “DIFERENÇAS” NO ENSINO FUNDAMENTAL: A EXPERIÊNCIA DAS RODAS DE CONVERSA

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    Neste artigo buscamos socializar uma atividade de ensino denominada “rodas de conversa sobre diferenças”, desenvolvida no ano de 2019 com turmas de 2Âș ano do Ensino Fundamental do ColĂ©gio de Aplicação da Universidade Federal de Santa Catarina. Tal atividade foi criada a partir de uma necessidade que sentĂ­amos de pensar em formas de abordar didĂĄtica e pedagogicamente a questĂŁo das “diferenças” com as crianças em sala de aula, para alĂ©m de um discurso social e politicamente correto de que precisamos “incluir” e respeitar as “diferenças”. A partir dessa demanda, buscamos coletivamente planejar açÔes que envolvessem as crianças e, sobretudo, mobilizassem a reflexĂŁo e oportunizassem a fala, pois, compreendĂ­amos que esse assunto merecia uma abordagem que nĂŁo fosse didatizada ou sistematizada de forma clĂĄssica, como ocorre com certos conteĂșdos escolares. Nesse sentido, elaboramos uma metodologia em que selecionĂĄvamos um disparador ou mobilizador da conversa, um artefato cultural dirigido ao pĂșblico infantil, que pudesse sensibilizar as crianças e engajĂĄ-las no diĂĄlogo conosco. Consideramos que a estratĂ©gia adotada cumpriu seu papel, pois observamos o entusiasmo e seriedade das crianças nas conversas, bem como o desenvolvimento de reflexĂ”es que possibilitaram a mudança de posturas, falas e comportamentos excludentes. Ademais, as rodas forneceram as professoras elementos para repensar a prĂĄtica pedagĂłgica de modo que todos fossem contemplados

    The RNA Binding Protein Quaking Regulates Formation of circRNAs

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    SummaryCircular RNAs (circRNAs), formed by non-sequential back-splicing of pre-mRNA transcripts, are a widespread form of non-coding RNA in animal cells. However, it is unclear whether the majority of circRNAs represent splicing by-products without function or are produced in a regulated manner to carry out specific cellular functions. We show that hundreds of circRNAs are regulated during human epithelial-mesenchymal transition (EMT) and find that the production of over one-third of abundant circRNAs is dynamically regulated by the alternative splicing factor, Quaking (QKI), which itself is regulated during EMT. Furthermore, by modulating QKI levels, we show the effect on circRNA abundance is dependent on intronic QKI binding motifs. Critically, the addition of QKI motifs is sufficient to induce de novo circRNA formation from transcripts that are normally linearly spliced. These findings demonstrate circRNAs are both purposefully synthesized and regulated by cell-type specific mechanisms, suggesting they play specific biological roles in EMT

    A massive, quiescent galaxy at redshift of z=3.717

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    In the early Universe finding massive galaxies that have stopped forming stars present an observational challenge as their rest-frame ultraviolet emission is negligible and they can only be reliably identified by extremely deep near-infrared surveys. These have revealed the presence of massive, quiescent early-type galaxies appearing in the universe as early as z∌\sim2, an epoch 3 Gyr after the Big Bang. Their age and formation processes have now been explained by an improved generation of galaxy formation models where they form rapidly at z∌\sim3-4, consistent with the typical masses and ages derived from their observations. Deeper surveys have now reported evidence for populations of massive, quiescent galaxies at even higher redshifts and earlier times, however the evidence for their existence, and redshift, has relied entirely on coarsely sampled photometry. These early massive, quiescent galaxies are not predicted by the latest generation of theoretical models. Here, we report the spectroscopic confirmation of one of these galaxies at redshift z=3.717 with a stellar mass of 1.7×\times1011^{11} M⊙_\odot whose absorption line spectrum shows no current star-formation and which has a derived age of nearly half the age of the Universe at this redshift. The observations demonstrates that the galaxy must have quickly formed the majority of its stars within the first billion years of cosmic history in an extreme and short starburst. This ancestral event is similar to those starting to be found by sub-mm wavelength surveys pointing to a possible connection between these two populations. Early formation of such massive systems is likely to require significant revisions to our picture of early galaxy assembly.Comment: 6 pages, 7 figures. This is the final preprint corresponding closely to the published version. Uploaded 6 months after publication in accordance with Nature polic
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