1,430 research outputs found
The hidden symbiotic star SU Lyn -- detection of flickering in U band
We report photometric observations of the hidden symbiotic star SU Lyn in the optical bands. In five nights we detect a weak flickering in U band with amplitude of about 0.05 magnitudes. No intranight variations are found in B, V, g' and r' bands. This is one more indication that the secondary component is a white dwarf accreting at low accretion rate. We also searched for intranight variability of a dozen related object (RR Boo, RT Boo, AM Cyg, AG Peg, BF Cyg, NQ Gem, StHa190, V627 Cas, XX Oph, FS Cet and Y Gem) in which no variability above the observational errors is detected.This work is part of the project KP-06-H28/2 08.12.2018 âBinary
stars with compact objectâ (Bulgarian National Science Fund). DM and BB acknowledge
project RD-08-100/2022. JM and PLE acknowledge support from Programa Operativo
FEDER 2014-2020 and ConsejerŽıa de EconomŽıa y Conocimiento of Junta de AndalucŽıa (Ref.
1380270)
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Association Between APOL1 Genotypes and Risk of Cardiovascular Disease in MESA (Multi-Ethnic Study of Atherosclerosis).
BACKGROUND:APOL1 genetic variants confer an increased risk for kidney disease. Their associations with cardiovascular disease (CVD) are less certain. We aimed to compare the prevalence of subclinical CVD and incidence of atherosclerotic CVD and heart failure by APOL1 genotypes among self-identified black participants of MESA (Multi-Ethnic Study of Atherosclerosis). METHODS AND RESULTS:Cross-sectional associations of APOL1 genotypes (high-risk=2 alleles; low-risk=0 or 1 allele) with coronary artery calcification, carotid-intimal media thickness, and left ventricular mass were evaluated using logistic and linear regression. Longitudinal associations of APOL1 genotypes with incident myocardial infarction, stroke, coronary heart disease, and congestive heart failure were examined using Cox regression. We adjusted for African ancestry, age, and sex. We also evaluated whether hypertension or kidney function markers explained the observed associations. Among 1746 participants with APOL1 genotyping (mean age 62 years, 55% women, mean cystatin C-based estimated glomerular filtration rate 89 mL/min per 1.73 m2, 12% with albuminuria), 12% had the high-risk genotypes. We found no difference in prevalence or severity of coronary artery calcification, carotid-intimal media thickness, or left ventricular mass by APOL1 genotypes. The APOL1 high-risk group was 82% more likely to develop incident heart failure compared with the low-risk group (95% confidence interval, 1.01-3.28). Adjusting for hypertension (hazard ratio, 1.80; 95% confidence interval, 1.00-3.24) but not markers of kidney function (hazard ratio, 1.86; 95% confidence interval, 1.03-3.35) slightly attenuated this association. The APOL1 high-risk genotypes were not significantly associated with other clinical CVD outcomes. CONCLUSIONS:Among blacks without baseline CVD, the APOL1 high-risk variants may be associated with increased risk for incident heart failure but not subclinical CVD or incident clinical atherosclerotic CVD
How do Fermi liquids get heavy and die?
We discuss non-Fermi liquid and quantum critical behavior in heavy fermion
materials, focussing on the mechanism by which the electron mass appears to
diverge at the quantum critical point. We ask whether the basic mechanism for
the transformation involves electron diffraction off a quantum critical spin
density wave, or whether a break-down in the composite nature of the heavy
electron takes place at the quantum critical point. We show that the Hall
constant changes continously in the first scenario, but may ``jump''
discontinuously at a quantum critical point where the composite character of
the electron quasiparticles changes.Comment: Revised version with many new references added. To appear as a
topical review in Journal of Physics: Condensed Matter Physics. Two column
version http://www.physics.rutgers.edu/~coleman/online/questions.ps.g
Characterizing larval swordfish habitat in the western tropical North Atlantic
Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Fisheries Oceanography, 27 (2018): 246-258, doi:10.1111/fog.12249.Swordfish Xiphias gladius (Linnaeus, 1758) are a circumglobal pelagic fish targeted by
multiple lucrative fisheries. Determining the distribution of swordfish larvae is important for
indicating reproductive activity and understanding the early life history of swordfish. We
identify and characterize larval swordfish distributions during peak swordfish spawning
throughout the Gulf of Mexico and western Caribbean Sea with generalized additive models
(GAMs) using catches of swordfish larvae during ichthyoplankton surveys in April and May of
2010, 2011, and 2012. The best fit GAM, as determined by stepwise, backward Akaike
Information Criterion selection, included both physiochemical (temperature at 5 m, sea surface
height anomaly (SSHA), eddy kinetic energy (EKE)), temporal (lunar illumination, hour of
sampling) and spatial (location) variables, while near-surface chlorophyll a concentration
residuals remained as a random effect. The highest probability of larval swordfish catch occurred
at sub-surface temperatures, SSHA, and EKE values indicative of boundary currents. Standard
lengths of larvae were larger further downstream in the boundary currents, despite high
variability in length with location due to multiple spawning locations of swordfish near these
currents. Probability of larval swordfish catch also peaked during the crescent and gibbous
moons, indicating a lunar periodicity to swordfish spawning. These results suggest that swordfish may spawn during select moon phases near boundary currents that transport their larvae to larval
and juvenile habitat including the northern Gulf of Mexico and coastal waters of the southeast
United States.NASA Grant Numbers: NNX11AP76G, NNX08AL06
The effect of Helicobacter pylori infection on growth velocity in young children from poor urban communities in Ecuador
SummaryObjectiveTo characterize the potential effects of Helicobacter infections on growth velocity in low socioeconomic status young children in a developing country.MethodsChildren were recruited in poor suburbs of Quito, Ecuador. Normally nourished, mildly and substantially malnourished children (defined using weight-for-age Z-scores at recruitment) formed equal strata. Six height and weight measurements were collected during one year. Enrollment and exit serum samples were analyzed for anti-Helicobacter IgG and exit non-diarrheal feces tested for Helicobacter antigen.ResultsAmong 124 participants (enrollment age 19±9 months), 76 (61%) excreted fecal antigen at exit (were infected). Of these, 44 were seropositive at least once (chronic infections) and 32 tested seronegative both times (new or acute phase infections). The adjusted linear growth velocity during follow-up in children with new infections was reduced by 9.7 (3.8, 15.6) mm/year compared to uninfected controls and 6.4 (0.0, 12.9) mm/year compared to children with chronic infections. The effects of Helicobacter infections on ponderal growth were not significant.ConclusionThese results suggest that linear growth velocity is reduced in young children during the initial phase of Helicobacter infection
Teacher knowledge and attitudes towards inclusion: a cross-cultural study in Ghana, Germany and Spain
A procedure for the change point problem in parametric models based on phi-divergence test-statistics
This paper studies the change point problem for a general parametric,
univariate or multivariate family of distributions. An information theoretic
procedure is developed which is based on general divergence measures for
testing the hypothesis of the existence of a change. For comparing the accuracy
of the new test-statistic a simulation study is performed for the special case
of a univariate discrete model. Finally, the procedure proposed in this paper
is illustrated through a classical change-point example
A marketing view of the customer value: Customer lifetime value and customer equity
Throughout this research the customer valuation trend in marketing is going to be reviewed, emphasizing Customer Lifetime Value and Customer Equity measures. The main theoretical contributions in the development and evolution of the Customer Lifetime Value concept are analysed. Customer Lifetime Value is also differentiated from Customer Equity and Customer Profitability analysis to estimate customer value in terms of firm profitability. Customer Lifetime Value and Customer Equity concepts are formally defined. Additionally, a classification of a set of published researches into Customer Lifetime Value and/or Customer Equity is developed. This classification has been posited according to several criteria that serves as a guide to key requirements for developing these types of models. Finally,
several conclusions, suggestions and future research streams are highlighted
Long-Term Kidney Function, Proteinuria, and Associated Risks among HIV-Infected and Uninfected Men in the MACS
Background: Factors affecting kidney function and proteinuria among HIV-positive (HIV+) and HIV-negative (HIVâ) persons need better characterization.
Methods: We evaluated estimated glomerular filtration rate (eGFR, ml/min per 1.73 m2) changes, proteinuria prevalence (a urine protein-to-creatinine ratio of â„0.2 at two consecutive visits) and associated factors among HIV+ and HIVâ men.
Results: There were 917 HIV+ men receiving HAART, 159 HIV+ men not receiving HAART, and 1305 HIVâ men seen from October 2003 to September 2014. Median annual eGFR change was â0.5, â0.8% for HIV+ and â0.3% for HIVâ men (P < 0.001). Factors significantly (P < 0.05) associated with more than 3% annual eGFR decline were HAART receipt (but no specific antiretroviral drug), age more than 50, hypertension, diabetes, current smoking. Proteinuria existed in 14.9% of visit-pairs among HAART recipients, 5.8% among non-HAART recipients, and 1.9% among HIVâ men, and was associated with subsequent annual more than 3% eGFR decline (odds ratio 1.80, P < 0.001). Proteinuria-associated factors also included HAART use (vs. HIVâ), age at least 50 (vs. <40), diabetes, hypertension, current smoking, hepatitis C virus-infection (all P < 0.05) and, among HIV+ men, lower CD4+ cell count, didanosine, saquinavir, or nelfinavir use (all P < 0.05). After adjusting for proteinuria, among HAART users, having a detectable HIV RNA, cumulative use of tenofovir disoproxil fumarate, emtricitabine, ritonavir, atazanavir, any protease inhibitor, or fluconazole were associated with more than 3% annual eGFR decline.
Conclusion: Longitudinal kidney function decline was associated with HAART use but no individual antiretroviral drug, and traditional kidney disease risks. Proteinuria was nearly seven times more common in HAART-treated men than HIVâ men, reflected recent eGFR decline and predicted subsequent eGFR declin
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