Persistent Hypertension is Associated with Low Hdl in Young Adults: an Evidence from Taiwan Five Years Population Based Cohort Study

Background: Hypertension (HT) is one of major risk factor for cardiovascular disease (CVD) and its combination with other risk factors, i.e. dyslipidemia, could worsen the health. The burden of CVD is now shifting to younger age, and its development is even in the earlier life period. Young adults with rare health check and lack of awareness in CVD risk factor may result in suboptimal management. This study aimed to investigate the association of persistent HT and low HDL level in 5 years follow up among young adults aged 15-25 years. Subjects and Methods: This study was done using Tw3SHH, a Taiwan population based cohort study (2002 to 2007), among young adults 15-25 years of age. HT was defined as the SBP>120mmHg and/or DBP>80 mmHg and/or respondent was told of having HT by medical personnel. HT development was classified based on their HT status in 2002 and 2007: “Non-HT (no HT both in 2002 and 2007)”, “Improved HT (HT in 2002 and no HT in 2007)”, ”Worsened HT (no HT in 2002 and HT in 2007)”, and “Persistent HT (HT both in 2002 and 2007)”. HDL was grouped based on NCEP-ATP III, and the low HDL defined as HDL<40mg/dl. Exercise, fatty food consumption and smoking status were based in self-reported questions. The data were analyzed by a multiple logistic reg¬res¬sion model to estimate the association of persistent HT and low HDL level in 5-years. Covariates were sex, age, smoking habit, exercise habit, fatty food con¬sump¬tion, and HbA1C. Results: About 9.35% of 727 study subjects had persistent HT. Compared to non-HT group, persistent HT group had higher risk of having low HDL level (crude OR= 3.70; CI 95%= 1.90 to 7.2; p<0.001; adjusted OR= 2.44; CI 95%= 1.18 to 5.03; p= 0.015). This association persisted (crude OR= 4.90; CI 95% 2.29 to 10.49; p<0.001; adjusted OR= 2.89; CI 95%= 1.34 to 6.24; p= 0.007) in sub¬group analysis among study subjects without low baseline HDL. Conclusion: Persistent HT is associated with low HDL level in 5 years follow up among young adults 15-25 years of age. Although universal screening in lipid profile among children and youth is still controversial, awareness to this condition should be raised. Keywords: cardiovascular, hypertension, dyslipidemia, HDL, young adul

Comments on QED with background electric fields

It is well known that there is a total cancellation of the \emph{factorizable} IR divergences in unitary interacting field theories, such as QED and quantum gravity. In this note we show that such a cancellation does not happen in QED with background electric fields which can produce pairs. There is no factorization of the IR divergences.Comment: 14 pages, 1 figur

Photon-Neutrino Interactions in Magnetic Field through Neutrino Magnetic Moment

We study the neutrino-photon processes like $\gamma\gamma\to\nu\bar{\nu}$ in the presence of uniform external magnetic field for the case when neutrinos can couple to the electromagnetic field directly through their dipole magnetic moment and obtain the stellar energy loss. The process would be of special relevance in astrophysical situations where standard left-handed neutrinos are trapped and the right handed neutrinos produced through the spin flip interaction induced by neutrino magnetic moment alone can freely stream out.Comment: LaTex2e file, 9 page

Matter-induced vertices for photon splitting in a weakly magnetized plasma

We evaluate the three-photon vertex functions at order $B$ and $B^{2}$ in a weak constant magnetic field at finite temperature and density with on shell external lines. Their application to the study of the photon splitting process leads to consider high energy photons whose dispersion relations are not changed significantly by the plasma effects. The absorption coefficient is computed and compared with the perturbative vacuum result. For the values of temperature and density of some astrophysical objects with a weak magnetic field, the matter effects are negligible.Comment: 14 pages, 1 figure. Accepted for publication in PR

Axial vector current in an electromagnetic field and low-energy neutrino-photon interactions

An expression for the axial vector current in a strong, slowly varying electromagnetic field is obtained. We apply this expression to the construction of the effective action for low-energy neutrino-photon interactions.Comment: 6 pages, references updated, final version to appear in Phys. Rev.

The relative importance of head, flux, and prior information in hydraulic tomography analysis

Using cross-correlation analysis, we demonstrate that flux measurements at observation locations during hydraulic tomography (HT) surveys carry nonredundant information about heterogeneity that are complementary to head measurements at the same locations. We then hypothesize that a joint interpretation of head and flux data, even when the same observation network as head has been used, can enhance the resolution of HT estimates. Subsequently, we use numerical experiments to test this hypothesis and investigate the impact of flux conditioning and prior information (such as correlation lengths and initial mean models (i.e., uniform mean or distributed means)) on the HT estimates of a nonstationary, layered medium. We find that the addition of flux conditioning to HT analysis improves the estimates in all of the prior models tested. While prior information on geologic structures could be useful, its influence on the estimates reduces as more nonredundant data (i.e., flux) are used in the HT analysis. Lastly, recommendations for conducting HT surveys and analysis are presented

Statistical Reliability with Applications

This chapter reviews fundamental ideas in reliability theory and inference. The first part of the chapter accounts for lifetime distributions that are used in engineering reliability analyis, including general properties of reliability distributions that pertain to lifetime for manufactured products. Certain distributions are formulated on the basis of simple physical properties, and other are more or less empirical. The first part of the chapter ends with a description of graphical and analytical methods to find appropriate lifetime distributions for a set of failure data. The second part of the chapter describes statistical methods for analyzing reliability data, including maximum likelihood estimation and likelihood ratio testing. Degradation data are more prevalent in experiments in which failure is rare and test time is limited. Special regression techniques for degradation data can be used to draw inference on the underlying lifetime distribution, even if failures are rarely observed. The last part of the chapter discusses reliability for systems. Along with the components that comprise the system, reliability analysis must take account of the system configuration and (stochastic) component dependencies. System reliability is illustrated with an analysis of logistics systems (e.g., moving goods in a system of product sources and retail outlets). Robust reliability design can be used to construct a supply chain that runs with maximum efficiency or minimum cost