1,748 research outputs found
ALMA Thermal Observations of Europa
We present four daytime thermal images of Europa taken with the Atacama Large
Millimeter Array. Together, these images comprise the first spatially resolved
thermal dataset with complete coverage of Europa's surface. The resulting
brightness temperatures correspond to a frequency of 233 GHz (1.3 mm) and a
typical linear resolution of roughly 200 km. At this resolution, the images
capture spatially localized thermal variations on the scale of geologic and
compositional units. We use a global thermal model of Europa to simulate the
ALMA observations in order to investigate the thermal structure visible in the
data. Comparisons between the data and model images suggest that the
large-scale daytime thermal structure on Europa largely results from bolometric
albedo variations across the surface. Using bolometric albedos extrapolated
from Voyager measurements, a homogenous model reproduces these patterns well,
but localized discrepancies exist. These discrepancies can be largely explained
by spatial inhomogeneity of the surface thermal properties. Thus, we use the
four ALMA images to create maps of the surface thermal inertia and emissivity
at our ALMA wavelength. From these maps, we identify a region of either
particularly high thermal inertia or low emissivity near 90 degrees West and 23
degrees North, which appears anomalously cold in two of our images.Comment: 9 pages, 3 figures, accepted for publication in the Astronomical
Journa
Farm to Migrant and Seasonal Head Start In Action
Migrant and Seasonal Head Start (MSHS) is a division of Head Start that serves the needs of migrant and seasonal farmworkers' children and their families and operates seasonally based on the needs of agricultural labor.1 Qualifying families earn at least 50% of their income from employment in fishing, agriculture, or agriculturalrelated work. MSHS operates in 40 states and provides services to more than 37,000 children annually, including early education services; medical, dental, and mental health screenings and referrals; nutritional services; parental involvement activities; and referrals to social service providers.2 Programs are run by a regional grantee organization that oversees multiple sites, coordinates services, and often addresses food procurement. With a built-in connection to agriculture and seasonal operation, integrating farm to early childhood education (ECE) food purchasing and education practices is a natural fit to enhance quality programming
Multiple dimensions of functional diversity affect stream fish taxonomic β-diversity
1. When investigating metacommunity dynamics, functional differences amongspecies are often assumed to be as important as environmental differences be-tween sites in determining β-diversity. However, few studies have examined theinfluence of functional diversity on β-diversity. We examine the relative importance of regional functional diversity partitioned by niche dimensions and environmental variation in structuring taxonomic β-diversity of stream fishes using a large dataset of stream fish assemblages (hereafter, simply β-diversity). We predicted that both functional diversity and environmental variation play a rolein determining β-diversity.2. We tested this prediction by modelling the patterns of stream fish β-diversity asa function of environmental variation, functional diversity and γ- richness across10,220 sites for 329 fish species using a series of conceptual path models.3. Environmental variation consistently affected β-diversity across all models,whereas functional diversity and γ- richness influenced β-diversity only in somemodels. We show that including relevant trait differences among species in pathmodels can improve their ability to explain β-diversity, suggesting that functional traits influence β-diversity.4. The ability of path models to explain β-diversity varied depending on the traitgrouping included in the model, demonstrating that specific path models representing different niche dimensions can improve the ability of a model to explain β-diversity. In addition, parsing traits into different niche dimensions revealed alternative patterns of functional diversity–β-diversity relationships that other-wise would have been missed.5. The selection of relevant traits and linked niche dimensions is critical for detecting relationships between functional diversity and β-diversity. Using traitsassociated with different niche dimensions allows for the identification of nichedimensions most strongly associated with species sorting and the detection ofpatterns missed by focusing on a single niche dimension. Determining the niche dimensions that influence β-diversity could provide insights into the processesdriving biodiversity and metacommunity dynamics, improving our ability to con-serve or restore aquatic communities
Alimentos Locales para Pequeños Comensales: Una Guía de Migrant & Seasonal Head Start para la Compra de Alimentos Locales
La intención de esta guía es ayudar a los programas MSHS a aumentar la cantidad de alimentos locales que compran y utilizan para los programas de atención y educación de la primera infancia (ECE, por sus siglas en inglés) que proporcionan servicios a los niños de trabajadores agrícolas migrantes y de temporada. Los proveedores del programa pueden seguir las instrucciones paso a paso y utilizar las herramientas -las cuales se complementan- para ayudar a los programas MSHS a comprar y utilizar más alimentos locales en sus programas alimentarios. Adicionalmente, los programas estatales de atención infantil a migrantes típicamente financiados por el gobierno federal y el estado en el cual el programa está localizado, pueden beneficiarse de esta guía. Ofreciendo servicios similares a los programas MSHS, pero con distintos requerimientos de elegibilidad, los programas estatales están abiertos durante diversos períodos de tiempo a lo largo del año, basados en la temporada agrícola. Los hogares de atención infantil brindan servicios a niños de distintas edades en un ambiente hogareño, algunos de los cuales podrían ser trabajadores migrantes durante la temporada agrícola. Estos programas reciben pagos directos por servicios de atención infantil o pagos financiados por el estado por guarderías para familias de bajos ingresos
Granja para los migrantes y de temporada Head Start en acción
La Migrant and Seasonal Head Start (MSHS) es una división de Head Start que atiende las necesidades de los niños y sus familias de los agricultores migrantes y de temporada con base en las necesidades del trabajo de agricultura.1 Las familias que cualifican se ganan por lo menos el 50% de sus ingresos de empleos en labores de pesca, agricultura o relacionados con la agricultura. La MSHS opera in 40 estados y le proporciona servicios a más de 37,000 niños anualmente, incluso servicios de educación temprana; pruebas de detección y remisiones médicas, dentales y mentales; servicios nutricionales; actividades de participación de los padres; y remisiones a proveedores de servicios sociales.2 Los programas son operados por organizaciones de beneficencia regional que supervisan múltiples sitios, coordinan servicios y a menudo abordan el suministro de alimentos. Con una conexión integrada a la agricultura y la operación de temporada, integrar las granjas a la educación preescolar (ECE, por sus siglas en inglés), la compra de alimentos y las prácticas educativas son un ajuste natural para mejorar la programación con calidad.
Resilience-Focused HIV Care to Promote Psychological Well-Being During COVID-19 and Other Catastrophes
The COVID-19 pandemic has adversely affected people with HIV due to disruptions in prevention and care services, economic impacts, and social isolation. These stressors have contributed to worse physical health, HIV treatment outcomes, and psychological wellness. Psychological sequelae associated with COVID-19 threaten the overall well-being of people with HIV and efforts to end the HIV epidemic. Resilience is a known mediator of health disparities and can improve psychological wellness and behavioral health outcomes along the HIV Continuum of Care. Though resilience is often organically developed in individuals as a result of overcoming adversity, it may be fostered through multi-level internal and external resourcing (at psychological, interpersonal, spiritual, and community/neighborhood levels). In this Perspective, resilience-focused HIV care is defined as a model of care in which providers promote optimum health for people with HIV by facilitating multi-level resourcing to buffer the effects of adversity and foster well-being. Adoption of resilience-focused HIV care may help providers better promote well-being among people living with HIV during this time of increased psychological stress and help prepare systems of care for future catastrophes. Informed by the literature, we constructed a set of core principles and considerations for successful adoption and sustainability of resilience-focused HIV care. Our definition of resilience-focused HIV care marks a novel contribution to the knowledge base and responds to the call for a multidimensional definition of resilience as part of HIV research
Bone mineral density and risk of heart failure in older adults: The Cardiovascular Health Study
Background
Despite increasing evidence of a common link between bone and heart health, the relationship between bone mineral density (
BMD
) and heart failure (
HF
) risk remains insufficiently studied.
Methods and Results
We investigated whether
BMD
measured by dual‐energy x‐ray absorptiometry was associated with incident
HF
in an older cohort. Cox models were stratified by sex and interactions of
BMD
with race assessed.
BMD
was examined at the total hip and femoral neck separately, both continuously and by World Health Organization categories. Of 1250 participants, 442 (55% women) developed
HF
during the median follow‐up of 10.5 years. In both black and nonblack women, neither total hip nor femoral neck
BMD
was significantly associated with
HF
; there was no significant interaction by race. In black and nonblack men, total hip, but not femoral neck,
BMD
was significantly associated with
HF
, with evidence of an interaction by race. In nonblack men, lower total hip
BMD
was associated with higher
HF
risk (hazard ratio, 1.13 [95% CI, 1.01–1.26] per 0.1 g/cm
2
decrement), whereas in black men, lower total hip
BMD
was associated with lower
HF
risk (hazard ratio, 0.74 [95% CI, 0.59–0.94]). There were no black men with total hip osteoporosis. Among nonblack men, total hip osteoporosis was associated with higher
HF
risk (hazard ratio, 2.83 [95% CI, 1.39–5.74]) compared with normal
BMD
.
Conclusions
Among older adults, lower total hip
BMD
was associated with higher
HF
risk in nonblack men but lower risk in black men, with no evidence of an association in women. Further research is needed to replicate these findings and to study potential underlying pathways.
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Gestational age impacts birth to placental weight ratio and umbilical cord oxygen values with implications for the fetal oxygen margin of safety
Background: We determined the impact of gestational age (GA) from near term to term to post-term on birth/placental weight ratio and cord oxygen values with implications for placental transport efficiency for oxygen, fetal O2 consumption relative to delivery or fractional O2 extraction, and oxygen margin of safety.
Materials and methods: A hospital database was used to obtain birth/placental weight ratios, cord PO2 and other information on patients delivering between Jan 1, 1990 and Jun 15, 2011 with GA \u3e 34 completed weeks (N=69,852). Oxygen saturation was calculated from the cord PO2 and pH data, while fractional O2 extraction was calculated from the oxygen saturation data. The effect of GA grouping on birth/placental weight ratio, cord PO2, O2 saturation, and fractional O2 extraction values, was examined in all patients adjusting for pregnancy and labor/delivery covariates, and in a subset of low-risk patients.
Results: Birth/placental weight ratio and umbilical venous O2 values increased with advancing GA, supporting the conjecture of increasing placental transport efficiency for oxygen. However, umbilical arterial O2 values decreased while fractional O2 extraction increased with successive GA groupings, indicating that fetal O2 consumption must be increasing relative to delivery.
Conclusions: Fetal O2 consumption can be seen as ever ‘outgrowing’ O2 delivery over the last weeks of pregnancy and leading to a continued lowering in systemic oxygen levels. While this lowering in oxygen may trigger feedback mechanisms with survival benefit, the ‘oxygen margin of safety’ will also be lowered increasing perinatal morbidity and mortality which appear to be hypoxia related
One-dimensional collision carts computer model and its design ideas for productive experiential learning
We develop an Easy Java Simulation (EJS) model for students to experience the
physics of idealized one-dimensional collision carts. The physics model is
described and simulated by both continuous dynamics and discrete transition
during collision. In the field of designing computer simulations, we discuss
briefly three pedagogical considerations such as 1) consistent simulation world
view with pen paper representation, 2) data table, scientific graphs and
symbolic mathematical representations for ease of data collection and multiple
representational visualizations and 3) game for simple concept testing that can
further support learning. We also suggest using physical world setup to be
augmented complimentary with simulation while highlighting three advantages of
real collision carts equipment like tacit 3D experience, random errors in
measurement and conceptual significance of conservation of momentum applied to
just before and after collision. General feedback from the students has been
relatively positive, and we hope teachers will find the simulation useful in
their own classes. 2015 Resources added:
http://iwant2study.org/ospsg/index.php/interactive-resources/physics/02-newtonian-mechanics/02-dynamics/46-one-dimension-collision-js-model
http://iwant2study.org/ospsg/index.php/interactive-resources/physics/02-newtonian-mechanics/02-dynamics/195-elastic-collisionComment: 6 pages, 8 figures, 1 table, 1 L. K. Wee, Physics Education 47 (3),
301 (2012); ISSN 0031-912
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