Effects of an extra Z′Z' gauge boson on the top quark decay t−−>cγt --> c \gamma

The effects of an extra $Z'$ gauge boson with family nonuniversal fermion couplings on the rare top quark decay $t --> c$gamma$are first examined in a model independent way and then in the minimal 331 model. It is found that the respective branching fraction is at most of the order of$10^{-8}$for$m_{Z'}=500$GeV and dramatically decreases for a heavier$Z'$boson. This results is in sharp contrast with a previous evaluation of this decay in the context of topcolor assisted technicolor models, which found that$B(t --> c \gamma)\sim 10^{-6}$for$m_{Z'}=1$ TeV.Comment: New paragraphs included to clarify our results, conclusion remains unchange

Static quantities of the W boson in the SU_L(3) X U_X(1) model with right-handed neutrinos

The static electromagnetic properties of the $W$ boson, $\Delta \kappa$ and $\Delta Q$, are calculated in the SU_L(3)} \times U_X(1) model with right-handed neutrinos. The new contributions from this model arise from the gauge and scalar sectors. In the gauge sector there is a new contribution from a complex neutral gauge boson $Y^0$ and a singly-charged gauge boson $Y^\pm$. The mass of these gauge bosons, called bileptons, is expected to be in the range of a few hundreds of GeV according to the current bounds from experimental data. If the bilepton masses are of the order of 200 GeV, the size of their contribution is similar to that obtained in other weakly coupled theories. However the contributions to both $\Delta Q$ and $\Delta \kappa$ are negligible for very heavy or degenerate bileptons. As for the scalar sector, an scenario is examined in which the contribution to the $W$ form factors is identical to that of a two-Higgs-doublet model. It is found that this sector would not give large corrections to $\Delta \kappa$ and $\Delta Q$.Comment: New material included. Final version to apppear in Physical Review

Maternal exposure to angiotensin converting enzyme inhibitors in the first trimester and risk of malformations in offspring: a retrospective cohort study

OBJECTIVE: To examine a reported association between use of angiotensin converting enzyme (ACE) inhibitors during the first trimester and risk of malformations in offspring. DESIGN: A population based, retrospective cohort study linking automated clinical and pharmacy databases including comprehensive electronic medical records. PARTICIPANTS: Pregnant women and their live born offspring (465,754 mother-infant pairs) in the Kaiser Permanente Northern California region from 1995 to 2008. MAIN OUTCOME MEASURE: Congenital malformation in live births. RESULTS: The prevalence of ACE inhibitor use in the first trimester only was 0.9/1000, and the use of other antihypertensive medications was 2.4/1000. After adjustment for maternal age, ethnicity, parity, and obesity, use of ACE inhibitors during the first trimester only seemed to be associated with increased risk of congenital heart defects in offspring compared with normal controls (those with neither hypertension nor use of any antihypertensives during pregnancy) (15/381 (3.9%) v 6232/400,021 (1.6%) cases, odds ratio 1.54 (95% confidence interval 0.90 to 2.62)). A similar association was observed for use of other antihypertensives (28/1090 (2.6%) cases of congenital heart defects, odds ratio 1.52 (1.04 to 2.21)). However, compared with hypertension controls (those with a diagnosis of hypertension but without use of antihypertensives) (708/29,735 (2.4%) cases of congenital heart defects), neither use of ACE inhibitors or of other antihypertensives in the first trimester was associated with increased congenital heart defects risk (odds ratios 1.14 (0.65 to 1.98) and 1.12 (0.76 to 1.64) respectively). CONCLUSIONS: Maternal use of ACE inhibitors in the first trimester has a risk profile similar to the use of other antihypertensives regarding malformations in live born offspring. The apparent increased risk of malformations associated with use of ACE inhibitors (and other antihypertensives) in the first trimester is likely due to the underlying hypertension rather than the medications

Therapeutic procedures and use of alternating antipyretic drugs for fever management in children

AbstractObjectiveThe evidence on the effectiveness of alternating antipyretics in fever management is scarce and indicates clinically negligible differences. The present study aimed to describe therapeutic procedures and the use of alternating antipyretics in children, and to evaluate associated factors.MethodsThis was a cross-sectional study with 692 children aged 0 to 6 years, living in Southern Brazil. Household interviews of the children's caregivers were conducted through cluster sampling using a structured questionnaire. A descriptive analysis was carried out, and the association between the use of alternating antipyretics and sociodemographic factors was evaluated. A total of 630 cases were analyzed (91.0%), corresponding to children with a history of fever.ResultsApproximately 73% of caregivers reported that the first measure adopted during the last fever episode was the administration of medication. The mean temperature considered as fever by caregivers was 37.4°C, and as high fever, 38.7°C. The use of alternating antipyretic therapy was reported by 26.7% of respondents, justified by the lack of response to monotherapy and medical indication, in most cases. The drugs most often used were dipyrone and paracetamol. Children whose primary caregiver was a parent with higher socioeconomic status and higher educational level received more alternating medications. Approximately 70% of the doses used were below the minimum recommended dose for the treatment of fever.ConclusionsThe use of medication to control fever is a common practice, including alternating antipyretic regimens. Most caregivers consider as fever temperatures lower than those established and they reported lack of response to monotherapy and medical indication as the main reasons for alternating medication

Social behavioral sensing: an exploratory study to assess learning motivation and perceived relatedness of university students using mobile sensing

Learning motivation plays a crucial role in student’s daily study life since it greatly affects academic performance and engagement. Perceived relatedness, based on self-determined theory, is an important predictor of learning motivation. Today, assessment for both of them still relies on subjective evaluations and self-reports, which is time-consuming and onerous. Hence, we propose a novel approach blended with mobile sensing by simultaneously collecting psychological measurements and objective mobile sensing data from N=58 undergraduates to explore new methods of assessing learning motivation and perceived relatedness. We identify a variety of social behavioral patterns from mobile sensing data, and investigate associations between psychological measures and these patterns. Our study helps enlighten what the new forms of assessing learning motivation and perceived relatedness in education could be, and paves the way for personalizing intervention in future research.This research was supported by the National Natural Science Foundation of China (No. 62077027), and the Humanity and Social Science Youth Foundation of Ministry of Education of China (No. 20YJC190034)

Determination of withdrawal times in individualized opportunistic screening colonoscopies

To investigate effects of bowel preparation, experience level of colonoscopists, and colonoscopy withdrawal time (CWT) on the quality of an individual opportunistic screening colonoscopy, according to adenoma detection rate (ADR).Data were retrospectively analyzed from opportunistic screening colonoscopies (n = 16,951) at 4 hospitals of various care levels in China.The ADR positively correlated with the experience level of the colonoscopist. The individualized CWT varied, depending on the quality of bowel preparation and the number of colonoscopies performed previously by the colonoscopist. In a setting of adequate bowel preparation, the mean CWT decreased with the increased experience of the colonoscopist. With poor and inadequate bowel preparation, no colonoscopist at any level of experience could obtain a satisfactory ADR.For adequately prepared colonoscopies, minimum CWTs have been determined. Repeat colonoscopy is strongly recommended for patients with poor bowel preparation, regardless of the colonoscopist's experience.publishersversionpublishe

Intrasubband and Intersubband Electron Relaxation in Semiconductor Quantum Wire Structures

We calculate the intersubband and intrasubband many-body inelastic Coulomb scattering rates due to electron-electron interaction in two-subband semiconductor quantum wire structures. We analyze our relaxation rates in terms of contributions from inter- and intrasubband charge-density excitations separately. We show that the intersubband (intrasubband) charge-density excitations are primarily responsible for intersubband (intrasubband) inelastic scattering. We identify the contributions to the inelastic scattering rate coming from the emission of the single-particle and the collective excitations individually. We obtain the lifetime of hot electrons injected in each subband as a function of the total charge density in the wire.Comment: Submitted to PRB. 20 pages, Latex file, and 7 postscript files with Figure

Comparison of Multi-Sample Variant Calling Methods for Whole Genome Sequencing

Rapid advancement of next-generation sequencing (NGS) technologies has facilitated the search for genetic susceptibility factors that influence disease risk in the field of human genetics. In particular whole genome sequencing (WGS) has been used to obtain the most comprehensive genetic variation of an individual and perform detailed evaluation of all genetic variation. To this end, sophisticated methods to accurately call high-quality variants and genotypes simultaneously on a cohort of individuals from raw sequence data are required. On chromosome 22 of 818 WGS data from the Alzheimer's Disease Neuroimaging Initiative (ADNI), which is the largest WGS related to a single disease, we compared two multi-sample variant calling methods for the detection of single nucleotide variants (SNVs) and short insertions and deletions (indels) in WGS: (1) reduce the analysis-ready reads (BAM) file to a manageable size by keeping only essential information for variant calling ("REDUCE") and (2) call variants individually on each sample and then perform a joint genotyping analysis of the variant files produced for all samples in a cohort ("JOINT"). JOINT identified 515,210 SNVs and 60,042 indels, while REDUCE identified 358,303 SNVs and 52,855 indels. JOINT identified many more SNVs and indels compared to REDUCE. Both methods had concordance rate of 99.60% for SNVs and 99.06% for indels. For SNVs, evaluation with HumanOmni 2.5M genotyping arrays revealed a concordance rate of 99.68% for JOINT and 99.50% for REDUCE. REDUCE needed more computational time and memory compared to JOINT. Our findings indicate that the multi-sample variant calling method using the JOINT process is a promising strategy for the variant detection, which should facilitate our understanding of the underlying pathogenesis of human diseases

Fermion contribution to the static quantities of arbitrarily charged vector bosons

We present an analysis of the one-loop contribution from left- and right-handed fermions to the static electromagnetic properties of an arbitrarily charged no self-conjugate vector boson $V$. Particular emphasis is given to the case of a no self-conjugate neutral boson $V^0$. Regardless the electric charge of the $V$ boson, a fermionic loop can induce the two CP-even form factors but only one CP-odd. As a result the corresponding electric dipole moment is directly proportional to the magnetic quadrupole moment. The CP-odd form factor might be severely suppressed since it requires the presence of both left- and right-handed fermions. The behavior of the form factors is analyzed for several scenarios of the fermion masses in the context of the decoupling theorem.Comment: 12 pages, 3 figures, submitted to Journal of Physics