244 research outputs found
Associations among Family Environment, Attention, and School Readiness for At-Risk Children
This study examined the developmental pathways from childrenâs 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 childrenâs 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 childrenâs 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 childrenâs 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
ATTENTION AND SCHOOL SUCCESS: The Long-Term Implications of Attention for School Success among Low-Income Children
This study examined the longitudinal associations between sustained attention in preschool and childrenâs 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 childrenâs 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 childrenâs 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
A metallicity study of 1987A-like supernova host galaxies
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
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
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).
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
Lethal effect of high concentrations of Parecoxib and Flunixin meglumine on the in vitro culture of bovine embryos
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 â€14 ”g/ml and P â€90 ”g/ml did not impair embryo development, although compiled data from non-lethal FM concentrations (â€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
Pan-STARRS and PESSTO search for an optical counterpart to the LIGO gravitational-wave source GW150914
This is the author accepted manuscript. The final version is available from Oxford University Press via http://dx.doi.org/10.1093/mnras/stw1893We searched for an optical counterpart to the first gravitational wave source discovered by LIGO (GW150914), using a combination of the Pan-STARRS1 wide-field telescope and the PESSTO spectroscopic follow-up programme. As the final LIGO sky maps changed during analysis, the total probability of the source being spatially coincident with our fields was finally only 4.2 per cent. Therefore we discuss our results primarily as a demonstration of the survey capability of Pan-STARRS and spectroscopic capability of PESSTO. We mapped out 442 square degrees of the northern sky region of the initial map. We discovered 56 astrophysical transients over a period of 41 days from the discovery of the source. Of these, 19 were spectroscopically classified and a further 13 have host galaxy redshifts. All transients appear to be fairly normal supernovae and AGN variability and none is obviously linked with GW150914. We illustrate the sensitivity of our survey by defining parameterised lightcurves with timescales of 4, 20 and 40 days and use the sensitivity of the Pan-STARRS1 images to set limits on the luminosities of possible sources. The Pan-STARRS1 images reach limiting magnitudes of = 19.2, 20.0 and 20.8 respectively for the three timescales. For long timescale parameterised lightcurves (with FWHMâ40d) we set upper limits of †â17.2 if the distance to GW150914 is = 400 ± 200 Mpc. The number of type Ia SN we find in the survey is similar to that expected from the cosmic SN rate, indicating a reasonably complete efficiency in recovering supernova like transients out to = 400 ± 200 Mpc.Pan-STARRS is supported by the University of Hawaii and the National Aeronautics and Space Administration's Planetary Defense Office under Grant No. NNX14AM74G. The Pan-STARRS-LIGO effort is in collaboration with the LIGO Consortium and supported by Queen's University Belfast. The Pan-STARRS1 Sky Surveys have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, the Queen's University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, and the National Aeronautics and Space Administration under Grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation Grant No. AST-1238877, the University of Maryland, Eotvos Lorand University (ELTE), and the Los Alamos National Laboratory. This work is based (in part) on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile as part of PESSTO, (the Public ESO Spectroscopic Survey for Transient Objects Survey) ESO programs 188.D-3003, 191.D-0935. Some of the data presented herein were obtained at the Palomar Observatory, California Institute of Technology. SJS acknowledges funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013)/ERC Grant agreement no [291222] and STFC grants ST/I001123/1 and ST/L000709/1. MF is supported by the European Union FP7 programme through ERC grant number 320360. KM acknowledges support from the STFC through an Ernest Rutherford Fellowship FOE acknowledges support from FONDECYT through postdoctoral grant 3140326.
This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration and data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation
Application of integrative genomics and systems biology to conventional and in vitro reproductive traits in cattle
Star Formation Laws and Efficiencies across 80 Nearby Galaxies
We measure empirical relationships between the local star formation rate
(SFR) and properties of the star-forming molecular gas on 1.5 kpc scales across
80 nearby galaxies. These relationships, commonly referred to as "star
formation laws," aim at predicting the local SFR surface density from various
combinations of molecular gas surface density, galactic orbital time, molecular
cloud free-fall time, and the interstellar medium dynamical equilibrium
pressure. Leveraging a multiwavelength database built for the PHANGS survey, we
measure these quantities consistently across all galaxies and quantify
systematic uncertainties stemming from choices of SFR calibrations and the
CO-to-H conversion factors. The star formation laws we examine show 0.3-0.4
dex of intrinsic scatter, among which the molecular Kennicutt-Schmidt relation
shows a 10% larger scatter than the other three. The slope of this
relation ranges , implying that the molecular gas
depletion time remains roughly constant across the environments probed in our
sample. The other relations have shallower slopes (),
suggesting that the star formation efficiency (SFE) per orbital time, the SFE
per free-fall time, and the pressure-to-SFR surface density ratio (i.e., the
feedback yield) may vary systematically with local molecular gas and SFR
surface densities. Last but not least, the shapes of the star formation laws
depend sensitively on methodological choices. Different choices of SFR
calibrations can introduce systematic uncertainties of at least 10-15% in the
star formation law slopes and 0.15-0.25 dex in their normalization, while the
CO-to-H conversion factors can additionally produce uncertainties of 20-25%
for the slope and 0.10-0.20 dex for the normalization.Comment: 10 pages main text + 2 appendices. ApJL in press. Data products
available at
https://www.canfar.net/storage/list/phangs/RELEASES/Sun_etal_2023 . Slides
summarizing key results can be found at
https://www.dropbox.com/s/5gsegexeo9n0t05/Sun_et_PHANGS_2023.pptx?dl=
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