21 research outputs found

    Complexidade e escala na investigação da eficácia do ensino: reflexões do estudo MET

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    Researchers and policymakers in the US and beyond increasingly seek to identify teaching qualities that are associated with academic achievement gains for K-12 students through effectiveness studies. Yet teaching quality varies with academic content and social contexts, involves multiple participants, and requires a range of skills, knowledge, and dispositions. In this essay, we address the inescapable tension between complexity and scale in research on teaching effectiveness. We provide five recommendations to study designers and analysts to manage this tension to enhance effectiveness research, drawing on our recent experiences as the first external analysts of the Measures of Effective Teaching (MET) study. Our recommendations address conceptual framing, the measurement of teaching (e.g., observation protocols, student surveys), sampling, classroom videoing, and the use and interpretation of value-added models.Investigadores y legisladores en los Estados Unidos y en otros países buscan identificar las cualidades de la enseñanza que se asocian con incrementos de desempeño académico para alumnos de primaria y secundaria a través de estudios de eficacia. Sin embargo, la calidad de la enseñanza varía según el contenido académico y los contextos sociales, involucra a múltiples participantes y requiere una variedad de habilidades, conocimientos y disposiciones. En este ensayo, abordamos la ineludible tensión entre la complejidad y la escala en la investigación sobre la eficacia de la enseñanza. Proveemos cinco recomendaciones a los diseñadores de estudios y analistas para manejar esta tensión y mejorar la investigación de eficacia, aprovechando nuestras experiencias recientes como los primeros analistas externos del estudio Measures of Effective Teaching (MET). Nuestras recomendaciones abordan el marco conceptual, la medición de la enseñanza (por ej., protocolos de observación, encuestas de estudiantes), el muestreo, el video en el aula y el uso e interpretación de modelos de valor agregado.Pesquisadores e legisladores nos Estados Unidos e em outros países buscam identificar as qualidades de ensino associadas ao aumento do desempenho acadêmico de alunos do ensino fundamental e médio por meio de estudos de eficácia. No entanto, a qualidade do ensino varia de acordo com o conteúdo acadêmico e os contextos sociais, envolve múltiplos participantes e requer uma variedade de habilidades, conhecimentos e disposições. Neste ensaio, abordamos a tensão inescapável entre complexidade e escala na pesquisa sobre a eficácia do ensino. Fornecemos cinco recomendações para projetistas e analistas de estudo para gerenciar essa tensão e melhorar a pesquisa sobre eficácia, alavancando nossas experiências recentes como os primeiros analistas externos do estudo Measures of Effective Teaching (MET). Nossas recomendações abordam a estrutura conceitual, a medição do ensino (por exemplo, protocolos de observação, pesquisas com estudantes), amostragem, vídeo em sala de aula e o uso e interpretação de modelos de valor agregado

    Extremely Red Galaxies at z = 5-9 with MIRI and NIRSpec:Dusty Galaxies or Obscured Active Galactic Nuclei?

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    We study a new population of extremely red objects (EROs) recently discovered by the James Webb Space Telescope (JWST) based on their NIRCam colors F277W − F444W &gt; 1.5 mag. We find 37 EROs in the Cosmic Evolution Early Release Science Survey (CEERS) field with F444W &lt; 28 mag and photometric redshifts between 5 &lt; z &lt; 7, with median z = 6.9 − 1.6 + 1.0 . Surprisingly, despite their red long-wavelength colors, these EROs have blue short-wavelength colors (F150W − F200W ∼ 0 mag) indicative of bimodal spectral energy distributions (SEDs) with a red, steep slope in the rest-frame optical, and a blue, flat slope in the rest-frame UV. Moreover, all these EROs are unresolved, point-like sources in all NIRCam bands. We analyze the SEDs of eight of them with MIRI and NIRSpec observations using stellar population models and active galactic nucleus (AGN) templates. We find that dusty galaxies or obscured AGNs provide similarly good SED fits but different stellar properties: massive and dusty, log M ⋆ / M ⊙ ∼ 10 and A V ≳ 3 mag, or low mass and obscured, log M ⋆ / M ⊙ ∼ 7.5 and A V ∼ 0 mag, hosting an obscured quasi-stellar object (QSO). SED modeling does not favor either scenario, but their unresolved sizes are more suggestive of AGNs. If any EROs are confirmed to have log M ⋆ / M ⊙ ≳ 10.5, it would increase the pre-JWST number density at z &gt; 7 by up to a factor ∼60. Similarly, if they are QSOs with luminosities in the L bol &gt; 1045-46 erg s−1 range, their number would exceed that of bright blue QSOs by more than three orders of magnitude. Additional photometry at mid-infrared wavelengths will reveal the true nature of the red continuum emission in these EROs and will place this puzzling population in the right context of galaxy evolution.</p

    CEERS Key Paper VII: Emission Line Ratios from NIRSpec and NIRCam Wide-Field Slitless Spectroscopy at z>2

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    We use James Webb Space Telescope Near-Infrared Camera Wide Field Slitless Spectroscopy (NIRCam WFSS) and Near-Infrared spectrograph (NIRSpec) in the Cosmic Evolution Early Release survey (CEERS) to measure rest-frame optical emission-line of 155 galaxies at z>2. The blind NIRCam grism observations include a sample of galaxies with bright emission lines that were not observed on the NIRSpec masks. We study the changes of the Ha, [OIII]/Hb, and [NeIII]/[OII] emission lines in terms of redshift by comparing to lower redshift SDSS and CLEAR samples. We find a significant (>3σ\sigma) correlation between [OIII]/Hb with redshift, while [NeIII]/[OII] has a marginal (2σ\sigma) correlation with redshift. We compare [OIII]/Hb and [NeIII]/[OII] to stellar mass and Hb SFR. We find that both emission-line ratios have a correlation with Hb SFR and an anti-correlation with stellar mass across the redshifts 0<z<9. Comparison with MAPPINGS~V models indicates that these trends are consistent with lower metallicity and higher ionization in low-mass and high-SFR galaxies. We additionally compare to IllustriousTNG predictions and find that they effectively describe the highest [OIII]/Hb ratios observed in our sample, without the need to invoke MAPPINGS models with significant shock ionizionation components.Comment: 16 pages, 11 figure

    First Look at z > 1 Bars in the Rest-Frame Near-Infrared with JWST Early CEERS Imaging

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    Stellar bars are key drivers of secular evolution in galaxies and can be effectively studied using rest-frame near-infrared (NIR) images, which trace the underlying stellar mass and are less impacted by dust and star formation than rest-frame UV or optical images. We leverage the power of {\it{JWST}} CEERS NIRCam images to present the first quantitative identification and characterization of stellar bars at z>1z>1 based on rest-frame NIR F444W images of high resolution (~1.3 kpc at z ~ 1-3). We identify stellar bars in these images using quantitative criteria based on ellipse fits. For this pilot study, we present six examples of robustly identified bars at z>1z>1 with spectroscopic redshifts, including the two highest redshift bars at ~2.136 and 2.312 quantitatively identified and characterized to date. The stellar bars at zz ~ 1.1-2.3 presented in our study have projected semi-major axes of ~2.9-4.3 kpc and projected ellipticities of ~0.41-0.53 in the rest-frame NIR. The barred host galaxies have stellar masses ~ 1×1010 1 \times 10^{10} to 2×10112 \times 10^{11} M⊙M_{\odot}, star formation rates of ~ 21-295 M⊙M_{\odot} yr−1^{-1}, and several have potential nearby companions. Our finding of bars at zz ~1.1-2.3 demonstrates the early onset of such instabilities and supports simulations where bars form early in massive dynamically cold disks. It also suggests that if these bars at lookback times of 8-10 Gyr survive out to present epochs, bar-driven secular processes may operate over a long time and have a significant impact on some galaxies by z ~ 0.Comment: 16 pages, 5 figures. Accepted for Publication in Astrophysical Journal Letter

    First Look at z &gt; 1 Bars in the Rest-frame Near-infrared with JWST Early CEERS Imaging

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    Stellar bars are key drivers of secular evolution in galaxies and can be effectively studied using rest-frame near-infrared (NIR) images, which trace the underlying stellar mass and are less impacted by dust and star formation than rest-frame UV or optical images. We leverage the power of JWST CEERS NIRCam images to present the first quantitative identification and characterization of stellar bars at z &gt; 1 based on rest-frame NIR F444W images of high resolution (∼1.3 kpc at z ∼ 1-3). We identify stellar bars in these images using quantitative criteria based on ellipse fits. For this pilot study, we present six examples of robustly identified bars at z &gt; 1 with spectroscopic redshifts, including the two highest-redshift bars at z ∼ 2.136 and 2.312 quantitatively identified and characterized to date. The stellar bars at z ∼ 1.1-2.3 presented in our study have projected semimajor axes of ∼2.9-4.3 kpc and projected ellipticities of ∼0.41-0.53 in the rest-frame NIR. The barred host galaxies have stellar masses ∼1 × 10 10 to 2 × 10 11 M ⊙ and star formation rates of ∼21-295 M ⊙ yr −1, and several have potential nearby companions. Our finding of bars at z ∼ 1.1-2.3 demonstrates the early onset of such instabilities and supports simulations where bars form early in massive dynamically cold disks. It also suggests that if these bars at lookback times of 8-11 Gyr survive out to present epochs, bar-driven secular processes may operate over a long time and have a significant impact on some galaxies by z ∼ 0.</p

    Clinically relevant physical benefits of exercise interventions in breast cancer survivors

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    Evidence is currently limited for the effect of exercise on breast cancer clinical outcomes. However, several of the reported physical benefits of exercise, including peak oxygen consumption, functional capacity, muscle strength and lean mass, cardiovascular risk factors, and bone health, have established associations with disability, cardiovascular disease risk, morbidity, and mortality. This review will summarize the clinically relevant physical benefits of exercise interventions in breast cancer survivors and discuss recommendations for achieving these benefits. It will also describe potential differences in intervention delivery that may impact outcomes and, lastly, describe current physical activity guidelines for cancer survivors

    Effect of exercise on taxane chemotherapy–induced peripheral neuropathy in women with breast cancer: A randomized controlled trial

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    Background Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting adverse effect of taxanes. We sought to evaluate the effect of exercise on taxane CIPN in women with breast cancer. Patients and Methods Women (n = 27) were randomized to immediate exercise (IE, during taxane chemotherapy) or delayed exercise (DE, after chemotherapy). Supervised aerobic, resistance, and balance training was offered 3 days a week for 8-12 weeks. CIPN symptoms and quality of life were assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ) C30 and CIPN20 (scored from 0 to 100). The percentage of participants reporting moderate to severe sensory symptoms (‘3/4’ or ‘4/4’ for CIPN20 sensory items) was also evaluated, along with clinical sensory testing at the lower limb (vibration sense and pinprick). Taxane treatment adherence, including relative dose intensity, was extracted from patient medical records. Assessments occurred at: baseline (before taxane chemotherapy), pre-cycle 4 (before the final taxane cycle), the end of chemotherapy, and follow-up (10-15 weeks after chemotherapy). Results No differences in the EORTC QLQ CIPN20 symptom scores were detected between groups at any time point. At pre-cycle 4, there was a significant difference between groups in patient-reported moderate to severe numbness in the toes or feet (IE: n = 1, 9%, DE: n = 7, 50%, P = .04) and impaired vibration sense in the feet (IE: n = 2, 18%, DE: n = 10, 83%, P < .01). Overall global health status/quality of life was higher in IE compared to DE at the end of chemotherapy (P = .05), yet both groups had worse CIPN20 sensory (Δ24.3 ± 4.6, P < .01) and motor symptom scores (Δ10.5 ± 1.9, P < .01) relative to baseline. By the end of chemotherapy, no differences between groups were found for moderate to severe numbness in the toes or feet (P = 1.0) or impaired vibration sense in the feet (P = .71). More IE participants received ≥ 85% relative dose intensity (IE: n = 12, 100%, DE: n = 10, 67%, P < .05). Conclusion Exercise may attenuate CIPN over the course of taxane chemotherapy and possibly improve taxane adherence in women with breast cancer. These findings, as well as whether exercise can attenuate CIPN by the end of taxane chemotherapy, should be confirmed in larger trials
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