342 research outputs found
Duodenal ulcer is a multifactorial disorder the role of pepsinogen I
Serum pepsinogen I (PGI) levels were measured in 231 duodenal ulcer (DU) patients and 100 sex and age-comparable healthy controls. Significantly higher mean serum PGI levels were found in DU patients than in controls (124,7 ± 3,4 ng/ml v. 92,9 ± 2,3 ng/ml; P < 0,001) (mean ± SE). These levels were higher in male DU patients than in female DU patients (128,5 ± 3,9 ng/IDl v. 107,4 ± 6,4 ng/ml; P < 0,05). Smoking was associated with elevated serum PGI levels in DU patients (145,3 ± 5,1 ng/ml v. 109,0 ± 4,2 ngl/ml; P < 0,001). Healed DUs were associated with lower mean serum PGI levels than active ulcers (110,9 ± 7,6 ng/ml v. 129,4 ± 3,8 ng/ml, P < 0,05). Whether patients were positive or negative for Helicobacter pylori, infection did not affect mean serum PGI levels. All the risk factors for DU may not affect serum PGI levels and DU may therefore be considered a multifactorial disease
Effects of C-Terminal Truncation on Autocatalytic Processing of Bacillus licheniformis gamma-Glutamyl Transpeptidase
The role of the C-terminal region of Bacillus licheniformis gamma-glutamyl transpeptidase (BlGGT) was investigated by deletion analysis. Seven C-terminally truncated BlGGTs lacking 581-585, 577-585, 576-585, 566-585, 558-585, 523-585, and 479-585 amino acids, respectively, were generated by site-directed mutagenesis. Deletion of the last nine amino acids had no appreciable effect on the autocatalytic processing of the enzyme, and the engineered protein was active towards the synthetic substrate L-gamma-glutamyl-p-nitroanilide. However, a further deletion to Val576 impaired the autocatalytic processing. In vitro maturation experiments showed that the truncated BlGGT precursors, pro-Delta (576-585), pro-Delta (566-585), and pro-Delta(558-585), could partially precede a time-dependent autocatalytic process to generate the L- and S-subunits, and these proteins showed a dramatic decrease in catalytic activity with respect to the wild-type enzyme. The parental enzyme (BlGGT-4aa) and BlGGT were unfolded biphasically by guanidine hydrochloride (GdnCl), but Delta(577-585), Delta(576-585), Delta(566-585), Delta(558-585), Delta(523-585), and Delta(479-585) followed a monophasic unfolding process and showed a sequential reduction in the GdnCl concentration corresponding to half effect and. Delta G(0) for the unfolding. BlGGT-4aa and BlGGT sedimented at similar to 4.85 S and had a heterodimeric structure of approximately 65.23 kDa in solution, and this structure was conserved in all of the truncated proteins. The frictional ratio (f/f(o)) of BlGGT-4aa, BlGGT, Delta(581-585), and Delta(577-585) was 1.58, 1.57, 1.46, and 1.39, respectively, whereas the remaining enzymes existed exclusively as precursor form with a ratio of less than 1.18. Taken together, these results provide direct evidence for the functional role of the C-terminal region in the autocatalytic processing of BlGGT
Generation Gap and the Impact of the Web on Goods Quality Perceptions
This study explores how age and general online shopping experience affect consumer perceptions on product quality uncertainty. Using the survey data collected from 549 consumers, we investigated how they perceive the uncertainty of product quality on six search, experience and credence goods. The ANOVA results show that age and the Web shopping experience of consumers are significant factors. A generation gap is indeed seen for all but one experience good. Web shopping experience is not a significant factor for search goods but is for experience and credence goods. There is an interaction effect between age and Web shopping experience for one credence good. Implications of these results are discussed
Multiple Local Curvature Gabor Binary Patterns for Facial Action Recognition
Curvature Gabor features have recently been shown to be powerful facial texture descriptors with applications on face recognition. In this paper we introduce their use in facial action unit (AU) detection within a novel framework that combines multiple Local Curvature Gabor Binary Patterns (LCGBP) on different filter sizes and curvature degrees. The proposed system uses the distances of LCGBP histograms between neutral faces and AU containing faces combined with an AU-specific feature selection and classification process. We achieve 98.6% overall accuracy in our tests with the extended Cohn-Kanade database, which is higher than achieved previously by any state-of-the-artmethod
Solar Neutrino Masses and Mixing from Bilinear R-Parity Broken Supersymmetry: Analytical versus Numerical Results
We give an analytical calculation of solar neutrino masses and mixing at
one-loop order within bilinear R-parity breaking supersymmetry, and compare our
results to the exact numerical calculation. Our method is based on a systematic
perturbative expansion of R-parity violating vertices to leading order. We find
in general quite good agreement between approximate and full numerical
calculation, but the approximate expressions are much simpler to implement. Our
formalism works especially well for the case of the large mixing angle MSW
solution (LMA-MSW), now strongly favoured by the recent KamLAND reactor
neutrino data.Comment: 34 pages, 14 ps figs, some clarifying comments adde
Measurement of the D+ and Ds+ decays into K+K-K+
We present the first clear observation of the doubly Cabibbo suppressed decay
D+ --> K-K+K+ and the first observation of the singly Cabibbo suppressed decay
Ds+ --> K-K+K+. These signals have been obtained by analyzing the high
statistics sample of photoproduced charm particles of the FOCUS(E831)
experiment at Fermilab. We measure the following relative branching ratios:
Gamma(D+ --> K-K+K+)/Gamma(D+ --> K-pi+pi+) = (9.49 +/- 2.17(statistical) +/-
0.22(systematic))x10^-4 and Gamma(Ds+ --> K-K+K+)/Gamma(Ds+ --> K-K+pi+) =
(8.95 +/- 2.12(statistical) +2.24(syst.) -2.31(syst.))x10^-3.Comment: 10 pages, 8 figure
New Measurements of the D+ to K* mu nu Form Factor Ratios
Using a large sample of D+ to K- pi+ mu+ nu decays collected by the FOCUS
photoproduction experiment at Fermilab, we present new measurements of two
semileptonic form factor ratios: rv and r2. We find rv = 1.504 \pm 0.057 \pm
0.039 and r2 = 0.875 \pm 0.049 \pm 0.064. Our form factor results include the
effects of the s-wave interference discussed in a previous paper.Comment: 12 pages, 5 figure
Study of Hadronic Five-Body Decays of Charmed Mesons
We study the decay of D+ and Ds+ mesons into charged five body final states,
and report the discovery of the decay mode D+ -> K+K-Pi+Pi+Pi-, as well as
measurements of the decay modes D+ -> K-Pi+Pi+Pi+Pi-, Ds+ -> K+K-Pi+Pi+Pi-, Ds+
-> PhiPi+Pi+Pi- and D+/Ds+ -> Pi+Pi+Pi+Pi-Pi-. An analysis of the resonant
substructure is also included, with evidence suggesting that both decays
proceed primarily through an a1 vector resonance.Comment: 11 pages, 3 figure
Observation of a 1750 MeV/c^2 Enhancement in the Diffractive Photoproduction of K^+K^-
Using the FOCUS spectrometer with photon beam energies between 20 and 160
\gev, we confirm the existence of a diffractively photoproduced enhancement in
at 1750 \mevcc with nearly 100 times the statistics of previous
experiments. Assuming this enhancement to be a single resonance with a
Breit-Wigner mass shape, we determine its mass to be
\mevcc and its width to be \mevcc. We find no
corresponding enhancement at 1750 \mevcc in , and again neglecting any
possible interference effects we place limits on the ratio . Our results are consistent with previous
photoproduction experiments, but, because of the much greater statistics,
challenge the common interpretation of this enhancement as the
seen in annihilation experiments.Comment: 10 pages, 5 figure
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