E. de Groot

Possible structures of neutral currents at PETRA/PEP and LEP

Abstract A conservative expansion of the Weinberg-Salam (WS) model to the group SU(2) × U(1) × G increases the structure of neutral currents in the PETRA/PEP/LEP range, while preserving all testable WS predictions at low energies. The special case of SU(2) × U(1) × Ũ(1) is treated in detail.

Low HDL cholesterol levels in type I Gaucher disease do not lead to an increased risk of cardiovascular disease

OBJECTIVE A low plasma high-density lipoprotein cholesterol (HDL-c) concentration is an important risk factor for the development of atherosclerotic cardiovascular disease. HDL-c levels are abnormally low in type I Gaucher disease (GD) patients. The aim of this study was to determine whether GD is associated with premature atherosclerosis. METHODS Lipid profiles, apolipoproteins, and carotid artery intima-media thickness (cIMT) were analyzed in 40 type I GD patients, 34 carriers and 41 control subjects. cIMT is a non-invasive validated biomarker for the status of atherosclerosis and present and future cardiovascular disease risk. RESULTS Compared to control subjects, patients showed decreased HDL-c (1.1+/-0.3 mmol/L) as well as mildly decreased low-density lipoprotein cholesterol (LDL-c) levels (2.8+/-0.7 mmol/L), with an increased ApoB/ApoA1 ratio. In carriers, HDL-c levels were normal, but LDL-c levels were decreased (2.7+/-0.8 mmol/L). Mean cIMT measurements were not different in the three study groups (patients: 0.63+/-0.1mm versus carriers: 0.64+/-0.1mm versus control subjects: 0.65+/-0.1 mm). CONCLUSION In Gaucher disease low HDL-c levels do not lead to premature atherosclerosis as assessed by cIMT measurement. This indicates that the inverse relationship between levels of HDL-c and risk of cardiovascular disease in the general population may not be present in all conditions characterised by low HDL-c levels.

Uncorrelated jet model for particle spectra and elastic proton proton scattering at very high energy

Abstract Assuming that the particles produced in a high-energy collision are uncorrelated, except for energy and momentum conservation, we derive a very simple formula, which exhibits the energy dependence of the relevant phase-space integral. Using this result it is a simple matter to derive the magnitude and the energy dependence of the average multiplicity and the total inelastic cross section. A relation between these two quantities is established and compared with the prediction of Feynmans parton model. A few single-particle spectra are calculated and compared with experiment. Choosing a simple form for the phases of the nucleon and meson wavefunctions we calculate the overlap function and hence the diffraction peak for elastic proton-proton scattering. In addition to the well-known effect of the meson phase we find also that the nucleon phase has a considerable influence on the form of the diffraction peak.

Long-term LDL-c lowering in heterozygous familial hypercholesterolemia normalizes carotid intima-media thickness

OBJECTIVE We investigated the effectiveness of statins in daily practice in reducing the arterial wall thicknesses by comparing the carotid intima-media thickness (cIMT) between statin-treated familial hypercholesterolemia (FH) patients and their unaffected spouses. METHODS FH subjects treated with LDL-c lowering medication for at least 5 years and their unaffected spouses were included in this observational study. Clinical data and carotid intima-media thickness (cIMT) as surrogate marker for atherosclerosis were acquired. RESULTS In total 40 FH patients, age 48.4±4.2 years, and their 40 unaffected spouses, age 47.4±3.9 years, were included. Pre-treatment total cholesterol levels of FH patients were on average 9.3±2.0 mmol/L. Treated FH patients and unaffected spouses exhibited similar LDL-c (3.8±1.5 vs. 3.5±1.1 mmol/L; p=0.25) and total cholesterol levels (5.8±1.6 vs. 5.6±1.1 mmol/L; p=0.56). Also, in a multivariate model cIMT adjusted for age and sex did not differ between affected and spouses (95% CI: -0.032 to 0.092 mm; p=0.34). CONCLUSION Long-term statin treatment normalizes cIMT in severe FH patients and therefore it is likely that the extreme risk of cardiovascular disease in FH patients is significantly reduced by this therapy.

Restrictions on possible early weak gauge boson from petra QED cut-off

Abstract Data on μ pair production in the presently accessible e + e − energy range put nontrivial restrictions on low mass weak gauge boson properties.

Implications of e+e- → μ+μ-, e+e- at PETRA/PEP energies on electroweak theories

Abstract The implication of measurements of μ pair production and Bhabha scattering at PETRA/PEP energies on electroweak theories are analysed in terms of single gauge boson as well as multi weak boson theories.

POSSIBLE STRUCTURES OF THE NEUTRAL CURRENT WITHIN A GAUGE-THEORY FRAMEWORK

We examine a class of gauge theories based on U(1)×SU(2)×G allowing for an arbitrary number of gauge bosons, while retaining the lowq2 four fermion interaction of the standard model. Measurable consequences fore+e−→μ+μ− ande+e−→e+e− at presently available as well as LEP energies are presented. Implications of the recently determined QED cut-offΛ− ≃ 100 GeV on gauge boson properties and the anomalous magnetic moment of the muon are pointed out.

Quantum statistics and the uncorrelated jet model at high energy

Abstract We show that the explicit introduction of quantum statistics in the uncorrelated jet model provides an enhancement of soft pion production. With increasing c.m. energy √ s , this results in a log s violation of Feynman scaling, a triangular rapidity distribution in place of the plateau, and a multiplicity growing as (log s ) 2 . Our predictions are found to be in good agreement with the behaviour observed in high-energy hadronic collisions.

Prevalence by sex of preclinical carotid atherosclerosis in newly diagnosed type 2 diabetes

BACKGROUND AND AIMS There is clinical trial evidence that only early, intensive risk factor control can reduce cardiovascular disease (CVD) morbidity and mortality in type 2 diabetes (T2DM). However, there is little information regarding preclinical atherosclerosis at diabetes diagnosis. We assessed carotid atherosclerosis in new-onset T2DM and control individuals without prior CVD. METHODS AND RESULTS In a cross-sectional case-control study, we determined intima-media thickness (IMT) and plaque (IMT ≥1.5 mm) by ultrasound at all carotid sites in new-onset T2DM patients and controls. We assessed 106 T2DM patients, median age 62 years, 46% women, 19% smokers, 54% with hypertension, and 41% with dyslipidemia and 99 non-diabetic subjects matched by age, sex, and cardiovascular risk factors. Compared to controls, T2DM patients had higher common carotid artery (CCA)-IMT (median 0.725 vs. 0.801 mm, p = 0.01), bulb-IMT (0.976 vs. 1.028 mm, p = 0.12), and internal carotid artery (ICA)-IMT (0.727 vs. 0.802 mm, p = 0.04). The prevalence of total plaque (60% vs. 72%, p = 0.06), ICA plaque (20% vs. 42%, p < 0.01), and harboring ≥3 plaques (16% vs. 35% p < 0.01) was also higher in T2DM. Plaque score (sum of maximum plaque heights) was also higher (p < 0.01) in T2DM. Diabetic women showed more advanced carotid atherosclerosis than diabetic men when they were compared with their respective non-diabetic counterparts. CONCLUSIONS There is a high prevalence of preclinical atherosclerosis (carotid plaque presence and burden) in new-onset T2DM subjects, especially in women. Early, still reversible, preclinical atherosclerosis may explain in part why early intervention is effective to prevent CVD in this patient population.

General electroweak mixing models and extended gauge theories

General electroweak mixing schemes containing an arbitrary number of weak bosons and agreeing with the predictions of the standard model for neutrino scattering and polarized electron scattering in the low energy approximation are analyzed using the propagator matrix formalism. The mean charged boson mass is bounded while the mean neutral boson mass is unbounded and determined as a function of the mean charged one. Under a special assumption on the electroweak mixing parameters the four fermion interaction agrees with the one of extended gauge theories and the mean boson masses agree with the boson masses of the standard model.