The antimicrobial effect of wine on Listeria innocua in a model stomach system

A model stomach, containing a food matrix and a synthetic gastric fluid, was used to study the bactericidal effect of ingested wine on Listeria innocua. Volumes of wine equivalent to the ingestion of one glass and half a bottle, led, over a period of less than 2 h, to a reduction of 3 and 4 logarithmic cycles of the initial population respectively. The influence of ethanol and organic acids, wine constituents with known antimicrobial properties, was investigated. Ethanol exhibited a higher bactericidal effect than the mixture of the main wine organic acids. When testing the organic acids separately, malic and lactic acids were found to have the strongest effect. The combination of ethanol with the organic acids acted synergistically but to a lesser extent than wine itself. The results suggest that the ingestion of wine during a meal may diminish the quantity of Listeria persisting further in the alimentary tract.     

Dielectric Resonators for the Measurement of Superconductor Thin Films Surface Impedance in Magnetic Fields at High Microwave Frequencies

We present the design and realization of cylindrical dielectric resonators operating in the 40–60 GHz frequency range, designed for the measurement of the surface resistance and of the surface reactance shift in High-T _c Superconductors (HTS) thin films in a dc magnetic field. The resonators are single tone, based on the TE ₀₁₁ mode, and multiple tone, the latter allowing in principle to exploit the simultaneous determination of the surface impedance at different frequencies. As an application example, we report the temperature and field dependencies of the effective surface impedance of some cuprate superconductors thin films. The results are compared with those obtained through the use of a standard metal cavity with a similar Q-factor and operating in the same frequency range. The comparison highlights a superior stability and a higher sensitivity, resulting in an increase of about two orders of magnitude in the resolution of the surface impedance measurement. By contrast, the dissipative part of the superconducting transition (above T/T _c = 0.97) is better studied with the metal cavity. We also present measurements in the vortex state in YBaCa₂Cu₃O_7−δ and Tl₂Ba₂CaCu₂O_8+x that show significantly different physics. PACS: 74.25 Nf.     

Robustness issues in optimal control of unstable plants

This paper presents a robustness analysis of the optimal solution of the step tracking problem in a one-degree of freedom control architecture, for the discrete-time multivariable (MIMO) case. It is shown that the resulting closed loop becomes arbitrarily fragile, i.e. the sensitivity peak becomes arbitrarily large, for certain reference directions. The cause of this problem is that the optimal controller depends on the reference direction. The paper shows that this dependence can be eliminated with an alternative formulation of the optimal problem where the cost is averaged over all reference directions.     

XPS studies of directly fluorinated HDPE: problems and solutions

X-ray photoelectron spectroscopy (XPS) applied to the study of fluorinated polymer surfaces presents several problems related both to peak assignment and to degradation. In this work, we analyse extensively the question of XPS peak assignments in this kind of surfaces. We conclude that in this kind of surfaces using binding energy differences between fluorine and carbon is better than using absolute binding energies. Also a useful relation between fluorine photoelectron energy vs. polymer composition expressed through the atomic ratio fluorine/carbon (F/C) was found. A protocol for data treatment is proposed and applied to a XPS study of the degradation induced by X-ray on high-density polyethylene surfaces modified by direct fluorination. Results obtained for the degradation, namely the atomic ratio F/C obtained by two different methods, combined with angle resolved X-ray photoelectron spectroscopy (ARXPS) were used to study the fluorine concentration profile in depth, producing self-consistent results.     

Compulsory notification of cysticercosis in Ribeir?o Preto-SP, Brazil

Cysticercosis is a severe public health problem in several regions of Asia, Africa and Latin America. Epidemiologic studies based on the frequency of cases observed in specialized neurology, neurosurgery and computed tomography services, at autopsy and in seroepidemiologic studies do not permit the determination of the true prevalence of the disease in the population. The objective of the present study was to investigate the prevalence of cysticercosis by compulsory notification. The coefficient of prevalence was 54 cases/100,000 inhabitants in the municipality of Ribeir?o Preto. The results also indicated that cysticercosis is not under control in our region since 21% of cases presented the active form of the disease. Compulsory notification proved to be a valuable resource for the epidemiologic study of cysticercosis, also permitting the mapping of more affected areas for a better direction of prevention strategies.     

Performance as a function of increased minority hiring.

Examined the impact of increasing the percentage of hires (above the T. A. Cleary [1968] fair-hiring level) from minority groups with demonstrated lower average job performance. Increased minority hiring resulted in only a small performance loss, even when minority hiring exceeded the minority applicant representation. However, when minorities were hired at a rate equal to or greater than their applicant representation, the expected performance loss among the hired minorities was much greater than performance loss across all hires. More important, the discrepancy in performance between majority and minority hires increased as minority hiring increased. With minority hiring above the level of minority applicant representation, this discrepancy exceeded the population difference in performance between the 2 groups. These findings suggest additional considerations when raising minority hiring above minority applicant representation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prospective study of carotid endarterectomy and contralateral carotid occlusion

A total of 700 patients who had carotid endarterectomy (CEA) in the UK and Ireland during a 6-month interval between March and August 1994 were studied prospectively. Some 108 patients (15.4 per cent) had a contralateral internal carotid artery occlusion. Previous reports have shown an associated stroke rate of about 10 per cent in these patients. This study assessed complications and outcome for patients undergoing CEA with contralateral internal carotid artery occlusion compared with those without. The indications for surgery were comparable between the two groups although the patients with occlusion had a slightly higher incidence of arrhythmia and stroke. Intraoperative shunts were used in a significantly higher proportion of those with occlusion (83.3 versus 64.7 per cent, P = 0.0001). The combined death and stroke rate for patients with occlusion was 5.6 per cent compared with 2.4 per cent for the remainder (P not significant). On the basis of the present data, CEA with a contralateral carotid artery occlusion carries only a slight increase in the rate of postoperative stroke and death. This increase was not statistically significant and is lower than that reported previously.     

RBS/channelling study of ion-implanted and proton-exchanged LiNbO3:Nd:MgO planar waveguides

We present a structural study of two Nd³⁺/MgO codoped LiNbO₃ waveguides fabricated by two different methods: ion-implantation and proton-exchange. Rutherford backscattering spectrometry in combination with channelling was used to study the influence of the waveguide fabrication method on the possible modification of the LiNbO₃ crystal structure within the waveguiding layer. The results show that the ion-implanted waveguide mainly maintains the same properties as the virgin crystal, apart from a deterioration of a thin surface layer, whilst the proton-exchanged waveguide exhibits a quite different behaviour, although its surface is less damaged.