169 research outputs found
Galactic contamination in the QMAP experiment
We quantify the level of foreground contamination in the QMAP Cosmic
Microwave Background (CMB) data with two objectives: (a) measuring the level to
which the QMAP power spectrum measurements need to be corrected for foregrounds
and (b) using this data set to further refine current foreground models. We
cross-correlate the QMAP data with a variety of foreground templates. The 30
GHz Ka-band data is found to be significantly correlated with the Haslam 408
MHz and Reich and Reich 1420 MHz synchrotron maps, but not with the Diffuse
Infrared Background Experiment (DIRBE) 240, 140 and 100 micron maps or the
Wisconsin H-Alpha Mapper (WHAM) survey. The 40 GHz Q-band has no significant
template correlations. We discuss the constraints that this places on
synchrotron, free-free and dust emission. We also reanalyze the
foreground-cleaned Ka-band data and find that the two band power measurements
are lowered by 2.3% and 1.3%, respectively.Comment: 4 ApJL pages, including 4 figs. Color figures and data at
http://www.hep.upenn.edu/~angelica/foreground.html#qmap or from
[email protected]
Integration of heterogeneous functional genomics data in gerontology research to find genes and pathway underlying aging across species.
Understanding the biological mechanisms behind aging, lifespan and healthspan is becoming increasingly important as the proportion of the world\u27s population over the age of 65 grows, along with the cost and complexity of their care. BigData oriented approaches and analysis methods enable current and future bio-gerontologists to synthesize, distill and interpret vast, heterogeneous data from functional genomics studies of aging. GeneWeaver is an analysis system for integration of data that allows investigators to store, search, and analyze immense amounts of data including user-submitted experimental data, data from primary publications, and data in other databases. Aging related genome-wide gene sets from primary publications were curated into this system in concert with data from other model-organism and aging-specific databases, and applied to several questions in genrontology using. For example, we identified Cd63 as a frequently represented gene among aging-related genome-wide results. To evaluate the role of Cd63 in aging, we performed RNAi knockdown of the C. elegans ortholog, tsp-7, demonstrating that this manipulation is capable of extending lifespan. The tools in GeneWeaver enable aging researchers to make new discoveries into the associations between the genes, normal biological processes, and diseases that affect aging, healthspan, and lifespan
Associations between HIV Antiretroviral Therapy and the Prevalence and Incidence of Pregnancy in Rakai, Uganda
Background. Use of antiretroviral therapy (ART) may be associated with higher pregnancy rates.
Methods. The prevalence and incidence of pregnancy was assessed in 712 HIV+ pre-ART women of reproductive age (WRA) (15–45) and 244 HIV+ WRA initiating ART. Prevalence rate ratios (PRR), incidence rate ratios (IRR), and 95% confidence interval (CI) were assessed.
Results. The incidence of pregnancy was 13.1/100 py among women in pre-ART care compared to 24.6/100 py among women on ART (IRR = 0.54; 95% CI 0.37, 0.81, p < 0.0017). The prevalence of pregnancy at ART initiation was 12.0% with CD4 counts 100–250 compared with 3.2% with CD4 <100 (PRR = 3.24, CI 1.51–6.93), and the incidence of pregnancy while on ART was highest in women with a good immunologic response. Desire for more children was a very important factor in fertility.
Conclusion. ART was associated with increased pregnancy rates in HIV+ women, particularly those with higher CD4 counts and good immunologic response to therapy, suggesting a need to strengthen reproductive health services for both women and their partners that could address their fertility decisions/intentions particularly after ART initiation
A New Spin on Galactic Dust
We present a new puzzle involving Galactic microwave emission and attempt to
resolve it. On one hand, a cross-correlation analysis of the WHAM H-alpha map
with the Tenerife 10 and 15 GHz maps shows that the well-known DIRBE correlated
microwave emission cannot be dominated by free-free emission. On the other
hand, recent high resolution observations in the 8-10 GHz range with the Green
Bank 140 ft telescope by Finkbeiner et al. failed to find the corresponding 8
sigma signal that would be expected in the simplest spinning dust models. So
what physical mechanism is causing this ubiquitous dust-correlated emission? We
argue for a model predicting that spinning dust is the culprit after all, but
that the corresponding small grains are well correlated with the larger grains
seen at 100 micron only on large angular scales. In support of this grain
segregation model, we find the best spinning dust template to involve higher
frequency maps in the range 12-60 micron, where emission from transiently
heated small grains is important. Upcoming CMB experiments such as ground-based
interferometers, MAP and Planck LFI with high resolution at low frequencies
should allow a definitive test of this model.Comment: Minor revisions to match accepted ApJ version. 6 pages, 4 figs. Color
figures and more foreground information at
http://www.hep.upenn.edu/~angelica/foreground.html#spin or from
[email protected]
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Traditional Herbal Medicine Use Associated with Liver Fibrosis in Rural Rakai, Uganda
Background: Traditional herbal medicines are commonly used in sub-Saharan Africa and some herbs are known to be hepatotoxic. However little is known about the effect of herbal medicines on liver disease in sub-Saharan Africa. Methods: 500 HIV-infected participants in a rural HIV care program in Rakai, Uganda, were frequency matched to 500 HIV-uninfected participants. Participants were asked about traditional herbal medicine use and assessed for other potential risk factors for liver disease. All participants underwent transient elastography (FibroScan®) to quantify liver fibrosis. The association between herb use and significant liver fibrosis was measured with adjusted prevalence risk ratios (adjPRR) and 95% confidence intervals (CI) using modified Poisson multivariable logistic regression. Results: 19 unique herbs from 13 plant families were used by 42/1000 of all participants, including 9/500 HIV-infected participants. The three most-used plant families were Asteraceae, Fabaceae, and Lamiaceae. Among all participants, use of any herb (adjPRR = 2.2, 95% CI 1.3–3.5, p = 0.002), herbs from the Asteraceae family (adjPRR = 5.0, 95% CI 2.9–8.7, p<0.001), and herbs from the Lamiaceae family (adjPRR = 3.4, 95% CI 1.2–9.2, p = 0.017) were associated with significant liver fibrosis. Among HIV infected participants, use of any herb (adjPRR = 2.3, 95% CI 1.0–5.0, p = 0.044) and use of herbs from the Asteraceae family (adjPRR = 5.0, 95% CI 1.7–14.7, p = 0.004) were associated with increased liver fibrosis. Conclusions: Traditional herbal medicine use was independently associated with a substantial increase in significant liver fibrosis in both HIV-infected and HIV-uninfected study participants. Pharmacokinetic and prospective clinical studies are needed to inform herb safety recommendations in sub-Saharan Africa. Counseling about herb use should be part of routine health counseling and counseling of HIV-infected persons in Uganda
The use of positron emission particle tracking (PEPT) to study milling of roll-compacted microcystalline cellulose ribbons
© 2015. Milling is a critical process for controlling the properties of the granules produced by roll compaction. In the current study, the positron emission particle tracking (PEPT) technique was used to examine the milling kinematics of roll-compacted ribbons at various milling speeds. Microcrystalline cellulose (MCC, Avicel PH-102) was used as the model feed material and a radioactive particle (tracer) was mixed with the MCC powder and roll-compacted to form sample ribbons. They were then milled using an oscillating mill at various speeds and the kinematics of the ribbons (trajectory, velocity, and occupancy) were quantitatively determined using PEPT. A close examination of the PEPT data reveals that, for milling MCC PH-102 ribbons using the oscillating mill considered in this study, the milling speed plays an important role: at low values, the milling process is dominated by cooperative motion of the ribbons with the blade (i.e. the speeds of the ribbons and the blade are similar, and the ribbons move along with the blade) and the ribbons are milled primarily by abrasion; as the speed increases the ribbons undergo more random motion involving collisions that results in an increase in ribbon breakage and hence an increase in the milling efficiency. It is shown that the PEPT technique is a useful technique for examining milling kinematics of roll-compacted ribbons
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