25 research outputs found
Search for lepton flavor violating decays of a heavy neutral particle in p-pbar collisions at root(s)=1.8 TeV
We report on a search for a high mass, narrow width particle that decays
directly to e+mu, e+tau, or mu+tau. We use approximately 110 pb^-1 of data
collected with the Collider Detector at Fermilab from 1992 to 1995. No evidence
of lepton flavor violating decays is found. Limits are set on the production
and decay of sneutrinos with R-parity violating interactions.Comment: Figure 2 fixed. Reference 4 fixed. Minor changes to tex
Genome-wide meta-analysis identifies six novel loci associated with habitual coffee consumption.
Coffee, a major dietary source of caffeine, is among the most widely consumed beverages in the world and has received considerable attention regarding health risks and benefits. We conducted a genome-wide (GW) meta-analysis of predominately regular-type coffee consumption (cups per day) among up to 91 462 coffee consumers of European ancestry with top single-nucleotide polymorphisms (SNPs) followed-up in ~30 062 and 7964 coffee consumers of European and African-American ancestry, respectively. Studies from both stages were combined in a trans-ethnic meta-analysis. Confirmed loci were examined for putative functional and biological relevance. Eight loci, including six novel loci, met GW significance (log10Bayes factor (BF)>5.64) with per-allele effect sizes of 0.03-0.14 cups per day. Six are located in or near genes potentially involved in pharmacokinetics (ABCG2, AHR, POR and CYP1A2) and pharmacodynamics (BDNF and SLC6A4) of caffeine. Two map to GCKR and MLXIPL genes related to metabolic traits but lacking known roles in coffee consumption. Enhancer and promoter histone marks populate the regions of many confirmed loci and several potential regulatory SNPs are highly correlated with the lead SNP of each. SNP alleles near GCKR, MLXIPL, BDNF and CYP1A2 that were associated with higher coffee consumption have previously been associated with smoking initiation, higher adiposity and fasting insulin and glucose but lower blood pressure and favorable lipid, inflammatory and liver enzyme profiles (P<5 × 10-8).Our genetic findings among European and African-American adults reinforce the role of caffeine in mediating habitual coffee consumption and may point to molecular mechanisms underlying inter-individual variability in pharmacological and health effects of coffee
GWAS for urinary sodium and potassium excretion highlights pathways shared with cardiovascular traits
© 2019, The Author(s). Urinary sodium and potassium excretion are associated with blood pressure (BP) and cardiovascular disease (CVD). The exact biological link between these traits is yet to be elucidated. Here, we identify 50 loci for sodium and 13 for potassium excretion in a large-scale genome-wide association study (GWAS) on urinary sodium and potassium excretion using data from 446,237 individuals of European descent from the UK Biobank study. We extensively interrogate the results using multiple analyses such as Mendelian randomization, functional assessment, co localization, genetic risk score, and pathway analyses. We identify a shared genetic component between urinary sodium and potassium expression and cardiovascular traits. Ingenuity pathway analysis shows that urinary sodium and potassium excretion loci are over-represented in behavioural response to stimuli. Our study highlights pathways that are shared between urinary sodium and potassium excretion and cardiovascular traits
Application and interpretation of multiple statistical tests to evaluate validity of dietary intake assessment methods
Momentum distribution of charged particles in jets in dijet events in p(p)over-bar collisions at root s=1.8 TeV and comparisons to perturbative QCD predictions
Inclusive momentum distributions of charged particles in restricted cones around jet axes were measured in dijet events with invariant dijet masses in the range 80 to 600 GeV/c(2). Events were produced at the Fermilab Tevatron in p (p) over bar collisions with a center of mass energy of 1.8 TeV and recorded by the Collider Detector at Fermilab. The results were compared to perturbative QCD calculations carried out in the framework of the modified leading log approximation (MLLA) and assuming local parton-hadron duality. It was shown that the data follow theoretical predictions quite well over the whole range of the jet energies included in this analysis. We extracted the MLLA cutoff scale Q(eff) and found a value of 230+/-40 MeV. The theoretical prediction of E(jet)sin theta(c) scaling, where theta(c) is the cone opening angle, was experimentally observed for the first time. From the MLLA fits to the data, two more parameters were extracted: the ratio of parton multiplicities in gluon and quark jets, r=N-partons(g-jet)/N-partons(q-jet)=1.9+/-0.5, and the ratio of the number of charged hadrons to the number of predicted partons in a jet, K-LPHD(charged)=N-hadrons(charged)/N-partons=0.56+/-0.10
Assessing the validity of a self-administered food-frequency questionnaire (FFQ) in the adult population of Newfoundland and Labrador, Canada
Background: The Food- Frequency Questionnaire (FFQ) is a dietary assessment tool frequently used in large-scale
nutritional epidemiology studies. The goal of the present study is to validate a self-administered version of the
Hawaii FFQ modified for use in the general adult population of Newfoundland and Labrador (NL).
Methods: Over a one year period, 195 randomly selected adults completed four 24-hour dietary recalls (24-HDRs)
by telephone and one subsequent self-administered FFQ. Estimates of energy and nutrients derived from the
24-HDRs and FFQs were compared (protein, carbohydrate, fibre, fat, vitamin A, carotene, vitamin D, and calcium).
Data were analyzed using the Pearson’s correlation coefficients, cross-classification method, and Bland–Altman plots.
Results: The mean nutrient intake values of the 24-HDRs were lower than those of the FFQs, except for protein in
men. Sex and energy-adjusted de-attenuated Pearson correlation coefficients for each nutrient varied from 0.13 to
0.61. Except for protein in men, all correlations were statistically significant with p < 0.05. Cross-classification analysis
revealed that on average, 74% women and 78% men were classified in the same or adjacent quartile of nutrient
intake when comparing data from the FFQ and 24-HDRs. Bland–Altman plots showed no serious systematic bias
between the administration of the two instruments over the range of mean intakes.
Conclusion: This 169-item FFQ developed specifically for the adult NL population had moderate relative validity
and therefore can be used in studies to assess food consumption in the general adult population of NL. This tool
can be used to classify individual energy and nutrient intakes into quartiles, which is useful in examining
relationships between diet and chronic disease
Search for the supersymmetric partner of the top quark in dilepton events from p(p)over-bar collisions at root s=1.8 TeV
We have searched for the supersymmetric partner of the top quark (stop) in
107 pb^{-1} of p-pbar collisions at \sqrt{s}= 1.8 TeV collected by the Collider
Detector at Fermilab (CDF). Within the framework of the Minimal Supersymmetric
extension of the Standard Model (MSSM) each of the pair-produced stops is
assumed to decay into a lepton, bottom quark and supersymmetric neutrino. Such
a scenario would give rise to events with two leptons, two hadronic jets, and a
substantial imbalance of transverse energy. No evidence of such a stop signal
has been found. We calculate a 95% confidence level (C.L.) upper limit on the
stop production cross section, which excludes stop masses in the region
(80<m_{\stop}<135 GeV/c^2) in the mass plane of stop versus sneutrino.Comment: 7 pages, 5 figures. Submitted to Physical Review Letter
Search for a W(') boson decaying to a top and bottom quark pair in 1.8 TeV p(p)over-bar collisions
We report the results of a search for a W(') boson produced in p (p)
over bar collisions at a center-of-mass energy of 1.8 TeV using a 106
pb(-1) data sample recorded by the Collider Detector at Fermilab. We
observe no significant excess of events above background for a W(')
boson decaying to a top and bottom quark pair. In a model where this
boson would mediate interactions involving a massive right-handed
neutrino (nu(R)) and have standard model strength couplings, we use
these data to exclude a W(') boson with mass between 225 and 536
GeV/c(2) at 95\% confidence level for M(W)(')>M(nuR) and between 225 and
566 GeV/c(2) at 95\% confidence level for M(W)(')<M(nuR)
Search for associated production of Upsilon and vector boson in p(p)over-bar collisions at root(s)over-bar=1.8 TeV
We present a search for associated production of the Y(1S) and a vector boson in 83 pb(-1) of p (p) over bar collisions at roots=1.8 TeV collected by the CDF experiment in 1994-1995. We find no evidence of the searched signal in the data, and set upper limits to the production cross sections
Central pseudorapidity gaps in events with a leading antiproton at the Fermilab tevatron (p)over-barp collider
We report a measurement of the fraction of events with a large pseudorapidity gap Deltaeta within the pseudorapidity region available to the proton dissociation products X in (p) over bar +p-->(p) over bar +X. For a final state (p) over bar of fractional momentum loss xi((p) over bar) and 4-momentum transfer squared t((p) over bar) within 0.063 is found to be 0.246+/-0.001 (stat)+/-0.042 (syst) [0.184+/-0.001 (stat)+/-0.043 (syst)]. Our results are compared with gap fractions measured in minimum bias (p) over barp collisions and with theoretical expectations