14 research outputs found

    Characterization of diamond-turned optics for SCALES

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    High-contrast imaging has been used to discover and characterize dozens of exoplanets to date. The primary limiting performance factor for these instruments is contrast, the ratio of exoplanet to host star brightness that an instrument can successfully resolve. Contrast is largely determined by wavefront error, consisting of uncorrected atmospheric turbulence and optical aberrations downstream of AO correction. Single-point diamond turning allows for high-precision optics to be manufactured for use in astronomical instrumentation, presenting a cheaper and more versatile alternative to conventional glass polishing. This work presents measurements of wavefront error for diamond-turned aluminum optics in the Slicer Combined with an Array of Lenslets for Exoplanet Spectroscopy (SCALES) instrument, a 2-5 micron coronagraphic integral field spectrograph under construction for Keck Observatory. Wavefront error measurements for these optics are used to simulate SCALES' point spread function using physical optics propagation software poppy, showing that SCALES' contrast performance is not limited by wavefront error from internal instrument optics.Comment: Techniques and Instrumentation for Detection of Exoplanets X

    Simulating medium-spectral-resolution exoplanet characterization with SCALES angular/reference differential imaging

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    SCALES (Slicer Combined with Array of Lenslets for Exoplanet Spectroscopy) is a 2 - 5 micron high-contrast lenslet-based integral field spectrograph (IFS) designed to characterize exoplanets and their atmospheres. The SCALES medium-spectral-resolution mode uses a lenslet subarray with a 0.34 x 0.36 arcsecond field of view which allows for exoplanet characterization at increased spectral resolution. We explore the sensitivity limitations of this mode by simulating planet detections in the presence of realistic noise sources. We use the SCALES simulator scalessim to generate high-fidelity mock observations of planets that include speckle noise from their host stars, as well as other atmospheric and instrumental noise effects. We employ both angular and reference differential imaging as methods of disentangling speckle noise from the injected planet signals. These simulations allow us to assess the feasibility of speckle deconvolution for SCALES medium resolution data, and to test whether one approach outperforms another based on planet angular separations and contrasts

    A TESS Dress Rehearsal: Planetary Candidates and Variables from K2 Campaign 17

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    We produce light curves for all ∼34,000 targets observed with K2 in Campaign 17 (C17), identifying planet candidates, eclipsing binaries, and other periodic variables. The forward-facing direction of the C17 field means follow-up can begin immediately now that the campaign has concluded and interesting targets have been identified. The C17 field has a large overlap with C6, so this latest campaign also offers an infrequent opportunity to study a large number of targets already observed in a previous K2 campaign. The timing of the C17 data release, shortly before science operations begin with the Transiting Exoplanet Survey Satellite (TESS), also lets us exercise some of the tools and methods developed for identification and dissemination of planet candidates from TESS. We find excellent agreement between these results and those identified using only K2-based tools. Among our planet candidates are several planet candidates with sizes <4 R ⊕ and orbiting stars with Kp ≲ 10 (indicating good RV targets of the sort TESS hopes to find) and a Jupiter-sized single-transit event around a star already hosting a 6 day planet candidate

    Prevalência de sobrepeso e obesidade e fatores associados em escolares de área urbana de Chilpancingo, Guerrero, México, 2004 Prevalence of overweight and obesity, and associated factors in school children from urban area in Chilpancingo, Guerrero, Mexico, 2004

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    Investigou-se a prevalência de sobrepeso e obesidade e respectivos fatores associados em escolares mexicanos. O estudo teve delineamento transversal e amostra composta por 700 escolares. As prevalências de sobrepeso e obesidade foram calculadas segundo sexo e idade, e as medidas de associação (odds ratios) estimadas por pontos e por intervalos, utilizando-se a regressão logística multivariada. Para o conjunto de escolares, as prevalências de sobrepeso e obesidade foram 28,1% e 13,7%, respectivamente. Os fatores de risco para o sobrepeso foram: "número de anos de escolaridade da mãe"; "hábito de comer enquanto estuda ou assiste à TV"; "escores de freqüência de consumo de alimentos de risco > 12 pontos"; "atividades sedentárias > 1,6 horas/dia" e "peso ao nascer > 2.890 gramas". Os fatores de risco para a obesidade foram semelhantes àqueles detectados para o sobrepeso. Maior freqüência de atividades esportivas foi identificada como fator de proteção para ambos os desfechos. A detecção dos principais fatores associados ao sobrepeso e à obesidade indica o direcionamento de intervenções para a prevenção de doenças crônicas nessa população, cujos fatores de risco já podem ser identificados a partir da infância.<br>This study aimed to investigate the prevalence rates for overweight and obesity among Mexican schoolchildren, identifying factors associated with the outcomes. A cross-sectional study was conducted in a sample consisting of 700 schoolchildren. Prevalence rates were calculated according to age and gender, and odds ratios were estimated by point and intervals, using multivariate logistic regression. Overweight and obesity prevalence were 28.1% and 13.7%, respectively. Risk factors for overweight were: mother's schooling (in years); eating while studying or watching TV; scores for risk food items > 12 points; sedentary activities > 1.6 hours/day, and birth weight > 2,890 grams. Obesity risk factors were similar to those related to overweight. Higher frequency of sport activities was detected as a protective factor in both outcomes. The associated factors for overweight and obesity highlighted the focus for health programs to prevent chronic diseases in this population, for which risk factors can already be identified in childhood

    Design of SCALES: a 2-5 micron coronagraphic integral field spectrograph for Keck Observatory

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    editorial reviewedWe present the design of SCALES (Slicer Combined with Array of Lenslets for Exoplanet Spectroscopy) a new 2-5 micron coronagraphic integral field spectrograph under construction for Keck Observatory. SCALES enables low-resolution (R∼50) spectroscopy, as well as medium-resolution (R∼4,000) spectroscopy with the goal of discovering and characterizing cold exoplanets that are brightest in the thermal infrared. Additionally, SCALES has a 12x12" field-of-view imager that will be used for general adaptive optics science at Keck. We present SCALES's specifications, its science case, its overall design, and simulations of its expected performance. Additionally, we present progress on procuring, fabricating and testing long lead-time components

    Emotional Development in Adults with Autism and Intellectual Disabilities: A Retrospective, Clinical Analysis

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    Individuals with intellectual disability (ID) are at risk for additional autism spectrum disorders (ASD). A large amount of research reveals deficits in emotion-related processes that are relevant to social cognition in ASD. However, studies on the structure and level of emotional development (ED) assessing emotional maturity according to the normative trajectory in typically developing children are scares. The level of ED can be evaluated by the 'Scheme of Appraisal of Emotional Development' (SAED), a semi-structured interview with a close caregiver. The SAED assesses the level of emotional developmental based on a five stage system in 10 domains, for example, 'interaction with peers' or 'object permanence', which are conducive to the overall emotional developmental level. This study examined the ED as measured by the SAED in 289 adults (mean age: 36 years) with ID with and without additional ASD. A lower level in ED was observed in ASD/ID combined that corresponded to the ED of typically developing children aged 1.5-3 years versus an ED with a corresponding age of 3-7 years in ID individuals without ASD. Moreover, distinct strengths in 'object permanence', and weaknesses in 'interaction', 'verbal communication', 'experience of self', 'affect differentiation', 'anxiety', and 'handling of material objects' led to a characteristic pattern of ED in ASD. SAED domains with highest discriminative power between ID individuals with and without ASD (5/10) were used to predict ASD group membership. The classification using a selection of SAED domains revealed a sensitivity of 77.5% and a specificity of 76.4%. ASD risk increased 2.7-fold with every SAED level. The recognition of delayed and uneven pattern of ED contributes to our understanding of the emotion-related impairments in adults with ID and ASD these individuals. Assessment of intra-individual ED could add value to the standard diagnostic procedures in ID, a population at risk for underdiagnosed ASD. © 2013 Sappok et al
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