258 research outputs found

    ATTENTION AND SCHOOL SUCCESS: The Long-Term Implications of Attention for School Success among Low-Income Children

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    This study examined the longitudinal associations between sustained attention in preschool and children’s school success in later elementary school within a low-income sample (N = 2,403). Specifically, two facets of sustained attention (focused attention and lack of impulsivity) at age 5 were explored as independent predictors of children’s academic and behavioral competence across eight measures at age 9. Overall, the pattern of results indicates specificity between the facets of attention and school success, such that focused attention was primarily predictive of academic outcomes while impulsivity was mainly predictive of behavioral outcomes. Both facets of attention predicted teacher ratings of children’s academic skills and approaches to learning, which suggests that they jointly influence outcomes that span both domains of school success. Patterns of association were similar for children above and below the poverty line. Implications of these findings for interventions targeting school readiness and success among at-risk children are discussed.sustained attention, academic achievement, behavioral competence, low-income children

    Associations among Family Environment, Attention, and School Readiness for At-Risk Children

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    This study examined the developmental pathways from children’s family environment to school readiness within an at-risk sample (N = 1,701). Measures of the family environment (maternal parenting behaviors and maternal mental health) across early childhood were related to children’s observed sustained attention as well as to academic and behavioral outcomes at age 5 years. Results suggest specificity in the associations among attention and its correlates. Maternal parenting behaviors but not mental health explained individual differences in sustained attention, which in turn were associated with variability in children’s academic school readiness. Mediation tests confirmed that sustained attention partially accounted for the link between parenting behaviors and academic school readiness. While maternal mental health was associated with children’s behavioral school readiness, sustained attention did not play a mediating role. Findings indicate sustained attention as a potential target for efforts aimed at enhancing academic school readiness among predominantly poor and minority children.child development, educational success, parenting behaviors, school readiness, mental health

    A metallicity study of 1987A-like supernova host galaxies

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    The origin of the blue supergiant (BSG) progenitor of Supernova (SN) 1987A has long been debated, along with the role that its sub-solar metallicity played. We now have a sample of 1987A-like SNe that arise from the core collapse (CC) of BSGs. The metallicity of the explosion sites of the known BSG SNe is investigated, as well as their association to star-forming regions. Both indirect and direct metallicity measurements of 13 BSG SN host galaxies are presented, and compared to those of other CC SN types. Indirect measurements are based on the known luminosity-metallicity relation and on published metallicity gradients of spiral galaxies. To provide direct estimates based on strong line diagnostics, we obtained spectra of each BSG SN host both at the SN explosion site and at the positions of other HII regions. Continuum-subtracted Ha images allowed us to quantify the association between BSG SNe and star-forming regions. BSG SNe explode either in low-luminosity galaxies or at large distances from the nuclei of luminous hosts. Therefore, their indirectly measured metallicities are typically lower than those of SNe IIP and Ibc. This is confirmed by the direct estimates, which show slightly sub-solar values (12+log(O/H)=8.3-8.4 dex), similar to that of the Large Magellanic Cloud (LMC), where SN 1987A exploded. However, two SNe (1998A and 2004em) were found at near solar metallicity. SNe IIb have a metallicity distribution similar to that of BSG SNe. Finally, the association to star-forming regions is similar among BSG SNe, SNe IIP and IIn. Our results suggest that LMC metal abundances play a role in the formation of some 1987A-like SNe. This would naturally fit in a single star scenario for the progenitors. However, the existence of two events at nearly solar metallicity suggests that also other channels, e.g. binarity, contribute to produce BSG SNe.Comment: 28 pages, 17 figures; accepted for publication (Astronomy and Astrophysics); abstract abridged for arXiv submissio

    Laser processing optimization for large-area perovskite solar modules

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    The industrial exploitation of perovskite solar cell technology is still hampered by the lack of repeatable and high-throughput fabrication processes for large-area modules. The joint efforts of the scientific community allowed to demonstrate high-performing small area solar cells; however, retaining such results over large area modules is not trivial. Indeed, the development of deposition methods over large substrates is required together with additional laser processes for the realization of the monolithically integrated cells and their interconnections. In this work, we develop an efficient perovskite solar module based on 2D material engineered structure by optimizing the laser ablation steps (namely P1, P2, P3) required for shaping the module layout in series connected sub-cells. We investigate the impact of the P2 and P3 laser processes, carried out by employing a UV pulsed laser (pulse width = 10 ns; lambda = 355 nm), over the final module performance. In particular, a P2 process for removing 2D material-based cell stack from interconnection area among adjacent cells is optimized. Moreover, the impact of the P3 process used to isolate adjacent sub-cells after gold realization over the module performance once laminated in panel configuration is elucidated. The developed fabrication process ensures high-performance repeatability over a large module number by demonstrating the use of laser processing in industrial production

    Synergic use of two-dimensional materials to tailor interfaces in large area perovskite modules

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    In the field of halide perovskite solar cells (PSCs), interface engineering has been conceptualized and exploited as a powerful mean to improve solar cell performance, stability, and scalability. In this regard, here we propose the use of a multi two-dimensional (2D) materials as intra and inter layers in a mesoscopic PSCs. By combining graphene into both compact and mesoporous TiO2, Ti3C2Tx MXenes into the perovskite absorbing layer and functionalized-MoS2 at the interface between perovskite and the hole transporting layer, we boost the efficiency of PSCs (i.e., +10%) compared to the 2D materials-free PSCs. The optimized 2D materials-based structure has been successfully extended from lab-scale cell dimensions to large area module on 121 cm2 substrates (11 x11 cm2) till to 210 cm2 substrates (14.5 x14.5 cm2) with active area efficiency of 17.2% and 14.7%, respectively. The remarkable results are supported by a systematic statistical analysis, testifying the effectiveness of 2D materials interface engineering also on large area devices, extending the 2D materials-perovskite photovoltaic technology to the industrial exploitation

    Quadro citológico vaginal, concentração plasmåtica de progesterona durante a gestação e medidas fetais em paca (Cuniculus paca Linnaeus, 1766).

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    Em 27 pacas (Cuniculus paca Linnaeus, 1766) objetivou-se descrever aos 30, 60 e 90 dias (D) de prenhez diagnosticada por ultrassonografia (US), os tipos celulares do epitĂ©lio vaginal em esfregaços vaginais, relatar as condiçÔes de abertura da vulva e as caracterĂ­sticas do muco vaginal, determinar a concentração plasmĂĄtica de progesterona (P4) por radioimunoensaio, e ainda, mensurar por ultrassonografia (US) o diĂąmetro biparietal (DBP) fetal aos 60 e 90 dias de prenhez. No D30, 40% das amostras exibiram cĂ©lulas (com caracterĂ­sticas estrogĂȘnicas) superficiais e presença de nĂșcleos nus. Nos D60 e D90, cĂ©lulas parabasais, intermediĂĄrias, superficiais e naviculares estavam presentes nas mesmas proporçÔes, mas cĂ©lulas endocervicais foram descritas em apenas 73,9% e 69% das amostras daqueles dias, respectivamente. No D30 a maior proporção de cĂ©lulas naviculares e superficiais diferiu (p < 0,05) em relação aos outros tipos celulares presentes. O muco vaginal apresentou-se cristalino e fluido em 100% e em 70% das fĂȘmeas nos D30 e D60, respectivamente. Observou-se o vestĂ­bulo vaginal aberto em torno de 50% das fĂȘmeas em todos os dias de exames. Valores mĂ­nimos detectĂĄveis de P4 foram obtidos em 72% e em 83% das fĂȘmeas, enquanto que as mĂ©dias das medidas dos DBP foram 1,25 cm (± 0,16) e 2,34 cm (± 0,25) nos D60 e D90, respectivamente. O quadro citolĂłgico vaginal nos D30, D60 e D90 e o DBP fornecem elementos que contribuem para diagnĂłstico de gestação em pacas. A concentração de P4 demonstra a necessidade de maiores estudos da endocrinologia da gestação em pacas

    Combining Mini-Mental State Examination and Montreal Cognitive Assessment for assessing the clinical efficacy of cholinesterase inhibitors in mild Alzheimer's disease: a pilot study

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    Current drugs for Alzheimer's Disease (AD), such as cholinesterase inhibitors (ChEIs), exert only symptomatic activity. Different psychometric tools are needed to assess cognitive and non-cognitive dimensions during pharmacological treatment. In this pilot study, we monitored 33 mild-AD patients treated with ChEIs. Specifically, we evaluated the effects of 6 months (Group 1 = 17 patients) and 9 months (Group 2 = 16 patients) of ChEIs administration on cognition with the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA), and the Frontal Assessment Battery (FAB), while depressive symptoms were measured with the Hamilton Depression Rating Scale (HDRS). After 6 months (Group 1), a significant decrease in MoCA performance was detected. After 9 months (Group 2), a significant decrease in MMSE, MoCA, and FAB performance was observed. ChEIs did not modify depressive symptoms. Overall, our data suggest MoCA is a potentially useful tool for evaluating the effectiveness of ChEIs

    Efficacy and acceptability of transcranial direct current stimulation (tDCS) for major depressive disorder: An individual patient data meta-analysis

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    We evaluated the efficacy and acceptability of transcranial direct current stimulation (tDCS) for treating acute depressive episodes using individual patient data that provide more precise estimates than aggregate data meta-analysis. A systematic review of placebo-controlled trials on tDCS as only intervention was conducted until December-2018. Data from each study was collated to estimate odds ratio (OR) and number needed to treat (NNT) of response and remission, and depression improvement. Endpoints were pre-determined. Nine eligible studies (572 participants), presenting moderate/high certainty of evidence, were included. Active tDCS was significantly superior to sham for response (30.9% vs. 18.9% respectively; OR = 1.96, 95%CI [1.30–2.95], NNT = 9), remission (19.9% vs. 11.7%, OR = 1.94 [1.19–3.16], NNT = 13) and depression improvement (effect size of ÎČ = 0.31, [0.15–0.47]). Moreover, continuous clinical improvement was observed even after the end of acute tDCS treatment. There were no differences in all-cause discontinuation rates and no predictors of response were identified. To conclude, active tDCS was statistically superior to sham in all outcomes, although its clinical effects were moderate

    Lethal effect of high concentrations of Parecoxib and Flunixin meglumine on the in vitro culture of bovine embryos

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    Abstract Since cyclooxygenase (COX) inhibitors have been pointed out as potential treatments to increase pregnancy rates after embryo transfer, the present experiment aimed to evaluate the effects of flunixin meglumine (FM) and parecoxib (P), a COX-1 and 2 or COX-2 specific inhibitor, respectively, on the development of bovine embryos until the hatched blastocyst stage. In vitro produced bovine embryos were cultured in media with different concentrations of FM (0.14; 1.4; 14; 140 or 1400 ”g/ml) or P (0.09; 0.9; 9; 90 or 900 ”g/ml) and the production rates were evaluated. Concentrations of FM ≀14 ”g/ml and P ≀90 ”g/ml did not impair embryo development, although compiled data from non-lethal FM concentrations (≀14 ”g/ml) indicated a toxic effect enough to decrease the hatching rate of blastocysts. Concentrations of FM at 140 and 1400 ”g/ml and P at 900 ”g/ml were lethal as no cleavage was detected on presumptive zygotes

    Do spiral arms enhance star formation efficiency?

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    Spiral arms, as those of our own Milky Way, are some of the most spectacular features in disc galaxies. It has been argued that star formation should proceed more efficiently in spiral arms as a result of gas compression. Yet, observational studies have so far yielded contradictory results. Here, we examine arm/interarm surface density contrasts at ∌100 pc resolution in 28 spiral galaxies from the PHANGS survey. We find that the arm/interarm contrast in stellar mass surface density (Σ⋆) is very modest, typically a few tens of percent. This is much smaller than the contrasts measured for molecular gas (ÎŁmol) or star formation rate (ÎŁSFR) surface density, which typically reach a factor of ∌2 − 3. However, ÎŁmol and ÎŁSFR contrasts show a significant correlation with the enhancement in Σ⋆, suggesting that the small stellar contrast largely dictates the stronger accumulation of gas and star formation. All these contrasts increase for grand-design spirals compared to multi-armed and flocculent systems (and for galaxies with high stellar mass). The median star formation efficiency (SFE) of the molecular gas is 16% higher in spiral arms than in interarm regions, with a large scatter, and the contrast increases significantly (median SFE contrast 2.34) for regions of particularly enhanced stellar contrast (Σ⋆ contrast &gt; 1.97). The molecular-to-atomic gas ratio (ÎŁmol/ÎŁatom) is higher in spiral arms, pointing to a transformation of atomic to molecular gas. As a consequence, the total gas contrast (ÎŁmol + ÎŁatom) slightly drops compared to ÎŁmol (median 4% lower, working at ∌kpc resolution), while the SFE contrast increases when we include atomic gas (median 8% higher than for ÎŁmol). The contrasts show important fluctuations with galactocentric radius. We confirm that our results are robust against a number of effects, such as spiral mask width, tracers, resolution, and binning. In conclusion, the boost in the SFE of molecular gas in spiral arms is generally modest or absent, except for locations with exceptionally large stellar contrasts
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