103 research outputs found
Promoting Fathers\u27 Engagement with Children: Preventive Interventions for Low-Income Families
Few programs to enhance fathers\u27 engagement with children have been systematically evaluated, especially for low-income minority populations. In this study, 289 couples from primarily low-income Mexican American and European American families were randomly assigned to one of three conditions and followed for 18 months: 16-week groups for fathers, 16-week groups for couples, or a 1-time informational meeting. Compared with families in the low-dose comparison condition, intervention families showed positive effects on fathers\u27 engagement with their children, couple relationship quality, and children\u27s problem behaviors. Participants in couples\u27 groups showed more consistent, longer term positive effects than those in fathers-only groups. Intervention effects were similar across family structures, income levels, and ethnicities. Implications of the results for current family policy debates are discussed
The Effects of Supplemental Dietary Chitosan on Broiler Performance and Myopathic Features of White Striping
White striping (WS) is a common myopathy seen in fast-growing broilers. Studies have demonstrated that chitosan is effective as an antioxidant and has antiobesity and fat-absorption reduction properties. We hypothesized that the dietary supplementation of chitosan would have similar effects when fed to fast-growing broilers and would thus lower WS incidence and improve meat quality. One hundred twenty-six broilers were fed corn-soy diets. The grower and finisher diets contained either 0, 0.2, or 0.4% chitosan. After a 6 wk growth period, birds were euthanized, and then WS and gross pathology scores were assessed. Pectoralis major tissues were collected to evaluate cook loss, drip loss, histopathology scores, and the gene expression of CCR7, LECT2, CD36, PPARG, and PTGS2. There were no significant differences between the broiler weights, thus chitosan did not appear to compromise the overall growth of the broilers. Female broilers fed 0.4% chitosan had the lowest WS incidence, while male broiler fed 0.4% chitosan had the least cook loss. However, gene expression analyses did not offer insight into any grossly or histologically visualized differences in the muscles. Thus, while we can postulate that chitosan could have some positive effect in reducing WS incidence and improving meat quality, further studies are required to better scrutinize the mechanisms by which chitosan affects WS and other such myopathies in fast-growing broilers
Exploring the atmospheric dynamics of the extreme ultra-hot Jupiter KELT-9b using TESS photometry
We carry out a phase-curve analysis of the KELT-9 system using photometric
observations from NASA's Transiting Exoplanet Survey Satellite (TESS). The
measured secondary eclipse depth and peak-to-peak atmospheric brightness
modulation are ppm and ppm, respectively. The
planet's brightness variation reaches maximum minutes before the
midpoint of the secondary eclipse, indicating a
eastward shift in the dayside hot
spot from the substellar point. We also detect stellar pulsations on KELT-9
with a period of hours. The dayside emission of KELT-9b in
the TESS bandpass is consistent with a blackbody brightness temperature of
K. The corresponding nightside brightness temperature is
K, comparable to the dayside temperatures of the hottest known
exoplanets. In addition, we detect a significant phase-curve signal at the
first harmonic of the orbital frequency and a marginal signal at the second
harmonic. While the amplitude of the first harmonic component is consistent
with the predicted ellipsoidal distortion modulation assuming equilibrium
tides, the phase of this photometric variation is shifted relative to the
expectation. Placing KELT-9b in the context of other exoplanets with
phase-curve observations, we find that the elevated nightside temperature and
relatively low day-night temperature contrast agree with the predictions of
atmospheric models that include H dissociation and recombination. The
nightside temperature of KELT-9b implies an atmospheric composition containing
about 50% molecular and 50% atomic hydrogen at 0.1 bar, a nightside emission
spectrum that deviates significantly from a blackbody, and a 0.5-2.0 m
transmission spectrum that is featureless at low resolution.Comment: Published in AJ, updated with proof corrections. 17 pages, 8 figure
Exploring the Atmospheric Dynamics of the Extreme Ultrahot Jupiter KELT-9b Using TESS Photometry
We carry out a phase-curve analysis of the KELT-9 system using photometric observations from NASA's Transiting Exoplanet Survey Satellite (TESS). The measured secondary eclipse depth and peak-to-peak atmospheric brightness modulation are 650⁺¹⁴₋₁₅ and 566 ± 16 ppm, respectively. The planet's brightness variation reaches maximum 31 ± 5 minutes before the midpoint of the secondary eclipse, indicating a 5.°2 ± 0.°9 eastward shift in the dayside hot spot from the substellar point. We also detect stellar pulsations on KELT-9 with a period of 7.58695 ± 0.00091 hr. The dayside emission of KELT-9b in the TESS bandpass is consistent with a blackbody brightness temperature of 4600 ± 100 K. The corresponding nightside brightness temperature is 3040 ± 100 K, comparable to the dayside temperatures of the hottest known exoplanets. In addition, we detect a significant phase-curve signal at the first harmonic of the orbital frequency and a marginal signal at the second harmonic. While the amplitude of the first harmonic component is consistent with the predicted ellipsoidal distortion modulation assuming equilibrium tides, the phase of this photometric variation is shifted relative to the expectation. Placing KELT-9b in the context of other exoplanets with phase-curve observations, we find that the elevated nightside temperature and relatively low day–night temperature contrast agree with the predictions of atmospheric models that include H₂ dissociation and recombination. The nightside temperature of KELT-9b implies an atmospheric composition containing about 50% molecular and 50% atomic hydrogen at 0.1 bar, a nightside emission spectrum that deviates significantly from a blackbody, and a 0.5–2.0 μm transmission spectrum that is featureless at low resolution
Spitzer Reveals Evidence of Molecular Absorption in the Atmosphere of the Hot Neptune LTT 9779b
Non-rocky sub-Jovian exoplanets in high-irradiation environments are rare. LTT 9779b, also known as Transiting Exoplanet Survey Satellite (TESS) object of interest (TOI) 193.01, is one of the few such planets discovered to date, and the first example of an ultrahot Neptune. The planet's bulk density indicates that it has a substantial atmosphere, so to investigate its atmospheric composition and shed further light on its origin, we obtained Spitzer InfraRed Array Camera secondary eclipse observations of LTT 9779b at 3.6 and 4.5 μm. We combined the Spitzer observations with a measurement of the secondary eclipse in the TESS bandpass. The resulting secondary eclipse spectrum strongly prefers a model that includes CO absorption over a blackbody spectrum, incidentally making LTT 9779b the first TESS exoplanet (and the first ultrahot Neptune) with evidence of a spectral feature in its atmosphere. We did not find evidence of a thermal inversion, at odds with expectations based on the atmospheres of similarly irradiated hot Jupiters. We also report a nominal dayside brightness temperature of 2305 ± 141 K (based on the 3.6 μm secondary eclipse measurement), and we constrained the planet's orbital eccentricity to e < 0.01 at the 99.7% confidence level. Together with our analysis of LTT 9779b's thermal phase curves reported in a companion paper, our results set the stage for similar investigations of a larger sample of exoplanets discovered in the hot-Neptune desert, investigations that are key to uncovering the origin of this population
Spitzer Reveals Evidence of Molecular Absorption in the Atmosphere of the Hot Neptune LTT 9979b
Non-rocky sub-jovian exoplanets in high irradiation environments are rare.
LTT 9979b, also known as TESS Object of Interest (TOI) 193.01, is one of the
few such planets discovered to date, and the first example of an ultra-hot
Neptune. The planet's bulk density indicates that it has a substantial
atmosphere, so to investigate its atmospheric composition and shed further
light on its origin, we obtained {\it Spitzer} IRAC secondary eclipse
observations of LTT 9979b at 3.6 and 4.5 m. We combined the {\it Spitzer}
observations with a measurement of the secondary eclipse in the {\it TESS}
bandpass. The resulting secondary eclipse spectrum strongly prefers a model
that includes CO absorption over a blackbody spectrum, incidentally making LTT
9979b the first {\it TESS} exoplanet (and the first ultra-hot Neptune) with
evidence of a spectral feature in its atmosphere. We did not find evidence of a
thermal inversion, at odds with expectations based on the atmospheres of
similarly-irradiated hot Jupiters. We also report a nominal dayside brightness
temperature of 2305 141 K (based on the 3.6 m secondary eclipse
measurement), and we constrained the planet's orbital eccentricity to at the 99.7 \% confidence level. Together with our analysis of LTT
9979b's thermal phase curves reported in a companion paper, our results set the
stage for similar investigations of a larger sample of exoplanets discovered in
the hot Neptune desert, investigations which are key to uncovering the origin
of this population.Comment: 12 pages, 5 figures; accepted to ApJ Letter
Gene Expression Patterns of Dengue Virus-Infected Children from Nicaragua Reveal a Distinct Signature of Increased Metabolism
Dengue is a widespread viral disease for which over 3 billion people are at risk. There are no drug treatments or vaccines available for this disease. It is also difficult for physicians to predict which patients are at highest risk for the severe manifestations known as dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). We used genome-wide transcriptional profiling analysis to study peripheral blood responses to dengue among patients from Nicaragua. We found that patients with severe manifestations involving shock had very different transcriptional profiles from dengue patients with mild and moderate illness. We then compared our results with other microarray experiments on dengue patients available from public databases and confirmed that dengue is often associated with large changes to the metabolic processes within cells. This approach could identify prognostic markers for severe dengue as well as provide a better understanding of the pathophysiology associated with different grades of disease severity
Susceptibility and Response of Human Blood Monocyte Subsets to Primary Dengue Virus Infection
Human blood monocytes play a central role in dengue infections and form the majority of virus infected cells in the blood. Human blood monocytes are heterogeneous and divided into CD16− and CD16+ subsets. Monocyte subsets play distinct roles during disease, but it is not currently known if monocyte subsets differentially contribute to dengue protection and pathogenesis. Here, we compared the susceptibility and response of the human CD16− and CD16+ blood monocyte subsets to primary dengue virus in vitro. We found that both monocyte subsets were equally susceptible to dengue virus (DENV2 NGC), and capable of supporting the initial production of new infective virus particles. Both monocyte subsets produced anti-viral factors, including IFN-α, CXCL10 and TRAIL. However, CD16+ monocytes were the major producers of inflammatory cytokines and chemokines in response to dengue virus, including IL-1β, TNF-α, IL-6, CCL2, 3 and 4. The susceptibility of both monocyte subsets to infection was increased after IL-4 treatment, but this increase was more profound for the CD16+ monocyte subset, particularly at early time points after virus exposure. These findings reveal the differential role that monocyte subsets might play during dengue disease
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