708 research outputs found

    Trilingualism in the United States: A case study of an Arabic and Greek household

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    Recent studies suggest that trilingual families in the United States are experiencing limited resources due to failing efforts to promote heritage language (HL) maintenance, diversity, and language rights both nationally and locally. Using a case study methodology, this paper will address obstacles identified in an interview with an Arabic speaking mother raising a trilingual child along with a Greek speaking partner while living in a monolingual society (U.S.). There is a need to uncover complex language practices and issues that different trilingual groups in the United States experience in order to preserve their heritage languages (HL) and cultures. Qualitative data was based on a survey and a 70-minute long virtual interview conducted in 2022. Our case study analysis reveals that the child lacks cultural context to both HLs when learning them in a monolingual society. Nonetheless, our findings suggest that there seems to be a link between emotional investment and language development. The child’s closer relationship with the father’s family reports a faster HL acquisition and retention as opposed to the distant and limited interaction with the mother’s family. Additionally, data suggests that the child found it hard to build his own identity without the help of others who share the same cultures. This research aims to contribute to language policy reform nationally, which is necessary to provide children from diverse backgrounds in the United States with an inclusive, integrated education

    A Hisfologic Study of Lens Regeneration in Aphakic Rabbits

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    Lens regeneration occurs in New Zealand albino rabbits after endocapsular lens extraction, which leaves the anterior and posterior lens capsules relatively intact. Slit-lamp photography, histologic studies, and lens protein analysis confirmed the differentiation of lens fibers. In the current study, we performed a sequential analysis of the regenerating rabbit lens. After endocapsular phacoemulsification and irrigation/aspiration of the lens, rabbits were sacrificed at different time points for histologic evaluation. Similarities with embryologic development of the lens were evident, although in some sections, abnormal cellular proliferation occurred. By the 6th day after surgery, a monolayer of lens epithelial cells lined both the anterior and posterior capsules. At 1 month, the posterior epithelial cells had elongated, and nuclei had migrated anteriorly. At 2 months, lens cells were differentiating at the equatorial zone with gradual elongation, anterior migration of nuclei, and eventual loss of nuclei. Invest Ophthalmol Vis Sci 31:540-547,199

    The Association between Drought Exposure and Respiratory-Related Mortality in the United States from 2000 to 2018

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    Climate change has brought increasing attention to the assessment of health risks associated with climate and extreme events. Drought is a complex climate phenomenon that has been increasing in frequency and severity both locally and globally due to climate change. However, the health risks of drought are often overlooked, especially in places such as the United States, as the pathways to health impacts are complex and indirect. This study aims to conduct a comprehensive assessment of the effects of monthly drought exposure on respiratory mortality for NOAA climate regions in the United States from 2000 to 2018. A two-stage model was applied to estimate the location-specific and overall effects of respiratory risk associated with two different drought indices over two timescales (the US Drought Monitor and the 6-month and 12-month Evaporative Demand Drought Index). During moderate and severe drought exposure, respiratory mortality risk ratio in the general population increased up to 6.0% (95% Cr: 4.8 to 7.2) in the Northeast, 9.0% (95% Cr: 4.9 to 13.3) in the Northern Rockies and Plains, 5.2% (95% Cr: 3.9 to 6.5) in the Ohio Valley, 3.5% (95% Cr: 1.9 to 5.0) in the Southeast, and 15.9% (95% Cr: 10.8 to 20.4) in the Upper Midwest. Our results showed that age, ethnicity, sex (both male and female), and urbanicity (both metro and non-metro) resulted in more affected population subgroups in certain climate regions. The magnitude and direction of respiratory risk ratio differed across NOAA climate regions. These results demonstrate a need for policymakers and communities to develop more effective strategies to mitigate the effects of drought across regions

    Joint association between ambient air pollutant mixture and pediatric asthma exacerbations

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    Background: Exposure to air pollutants is known to exacerbate asthma, with prior studies focused on associations between single pollutant exposure and asthma exacerbations. As air pollutants often exist as a complex mixture, there is a gap in understanding the association between complex air pollutant mixtures and asthma exacerbations. We evaluated the association between the air pollutant mixture (52 pollutants) and pediatric asthma exacerbations. Method: This study focused on children (age ≤ 19 years) who lived in Douglas County, Nebraska, during 2016–2019. A seasonal- scale joint association between the outdoor air pollutant mixture adjusting for potential confounders (temperature, precipitation, wind speed, and wind direction) in relation to pediatric asthma exacerbation-related emergency department (ED) visits was evaluated using the generalized weighted quantile sum (qWQS) regression with repeated holdout validation. Results: We observed associations between air pollutant mixture and pediatric asthma exacerbations during spring (lagged by 5 days), summer (lag 0–5 days), and fall (lag 1–3 days) seasons. The estimate of the joint outdoor air pollutant mixture effect was higher during the summer season (adjusted-βWQS = 1.11, 95% confidence interval [CI]: 0.66, 1.55), followed by spring (adjusted-βWQS = 0.40, 95% CI: 0.16, 0.62) and fall (adjusted-βWQS = 0.20, 95% CI: 0.06, 0.33) seasons. Among the air pollutants, PM2.5, pollen, and mold contributed higher weight to the air pollutant mixture. Conclusion: There were associations between outdoor air pollutant mixture and pediatric asthma exacerbations during the spring, summer, and fall seasons. Among the 52 outdoor air pollutant metrics investigated, PM2.5, pollen (sycamore, grass, cedar), and mold (Helminthosporium, Peronospora, and Erysiphe) contributed the highest weight to the air pollutant mixture

    AXTAR: Mission Design Concept

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    The Advanced X-ray Timing Array (AXTAR) is a mission concept for X-ray timing of compact objects that combines very large collecting area, broadband spectral coverage, high time resolution, highly flexible scheduling, and an ability to respond promptly to time-critical targets of opportunity. It is optimized for submillisecond timing of bright Galactic X-ray sources in order to study phenomena at the natural time scales of neutron star surfaces and black hole event horizons, thus probing the physics of ultradense matter, strongly curved spacetimes, and intense magnetic fields. AXTAR's main instrument, the Large Area Timing Array (LATA) is a collimated instrument with 2-50 keV coverage and over 3 square meters effective area. The LATA is made up of an array of supermodules that house 2-mm thick silicon pixel detectors. AXTAR will provide a significant improvement in effective area (a factor of 7 at 4 keV and a factor of 36 at 30 keV) over the RXTE PCA. AXTAR will also carry a sensitive Sky Monitor (SM) that acts as a trigger for pointed observations of X-ray transients in addition to providing high duty cycle monitoring of the X-ray sky. We review the science goals and technical concept for AXTAR and present results from a preliminary mission design study.Comment: 19 pages, 10 figures, to be published in Space Telescopes and Instrumentation 2010: Ultraviolet to Gamma Ray, Proceedings of SPIE Volume 773

    Three Millisecond Pulsars in FERMI LAT Unassociated Bright Sources

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    We searched for radio pulsars in 25 of the non-variable, unassociated sources in the Fermi LAT Bright Source List with the Green Bank Telescope at 820 MHz. We report the discovery of three radio and gamma-ray millisecond pulsars (MSPs) from a high Galactic latitude subset of these sources. All of the pulsars are in binary systems, which would have made them virtually impossible to detect in blind gamma-ray pulsation searches. They seem to be relatively normal, nearby (<=2 kpc) millisecond pulsars. These observations, in combination with the Fermi detection of gamma-rays from other known radio MSPs, imply that most, if not all, radio MSPs are efficient gamma-ray producers. The gamma-ray spectra of the pulsars are power-law in nature with exponential cutoffs at a few GeV, as has been found with most other pulsars. The MSPs have all been detected as X-ray point sources. Their soft X-ray luminosities of ~10^{30-31} erg/s are typical of the rare radio MSPs seen in X-rays.Comment: Accepted for publication in ApJ Letter
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