Quantum non-demolition measurements using cold atoms in an optical cavity

Abstract

In this paper we present a theoretical analysis of a recent quantum non-demolition experiment in optics using cold atoms in a magneto-optical trap as a nonlinear medium. A signal beam and a meter beam from two independent lasers are coupled within a A-type three-level scheme in the D1 line of ⁸⁷Rb atoms. The experimental results for the relevant quantum correlations of the fields represent up to now the best achievement for a single back-action evading measurement. Moreover, they are found to be in remarkably good agreement with the theoretical predictions from a fully quantum model for three-level atoms in a doubly resonant cavity.     

Perinatal transmitted acute icteric hepatitis B in infants born to hepatitis B surface antigen-positive and anti-hepatitis Be-positive carrier mothers

Three infants born to mothers who were hepatitis B surface antigen (HBsAg) positive and had antibody to hepatitis Be antigen (anti-HBe), developed acute icteric hepatitis B within three months of birth. All three infants clinically recovered and developed circulating anti-HBs. Contrary to previous studies, these three cases indicate that mother-infant transmission of the hepatitis B virus (HBV) does occur in infants born to HBsAg-positive, HBe-Ag-negative carrier mothers, and these infants may develop severe acute icteric hepatitis. Therefore, immunoprophylaxis in such newborns may be indicated.     

Multicenter trial of d-alpha-tocopheryl polyethylene glycol 1000 succinate for treatment of vitamin E deficiency in children with chronic cholestasis

BACKGROUND: Malabsorption and deficiency of vitamin E causing neurological degeneration are common consequences of chronic childhood cholestatic liver disease. The objective of this study was to determine the long-term efficacy and safety of d-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) in correcting vitamin E deficiency in children with chronic cholestasis who were unresponsive to other forms of oral vitamin E. METHODS: Sixty vitamin E-deficient children with chronic cholestasis unresponsive to 70-212 IU.kg-1.day-1 of oral vitamin E were entered into a trial at eight centers in the United States. After initial evaluation, treatment was started with 25 IU.kg-1.day-1 of TPGS. Vitamin E status, neurological function quantitated by a specific scoring system, and clinical and biochemical parameters were monitored during therapy. RESULTS: All children responded to TPGS with normalization of vitamin E status. Neurological function, which had deteriorated before entry in the trial, improved in 25 patients, stabilized in 27, and worsened in only 2 after a mean of 2.5 years of therapy. No adverse effects were observed. CONCLUSIONS: TPGS (20-25 IU.kg-1.day-1) appears to be a safe and effective form of vitamin E for reversing or preventing vitamin E deficiency during chronic childhood cholestasis.     

Evaluation of the effect of preload force on resonance frequencies for a traveling wave ultrasonic motor

In this paper, a novel method of numerical computation of the natural frequencies, depending on the most important running parameters for an ultrasonic motor, is described. The analyzed configuration by the Space Division of Alenia Spazio, Rome, within an Italian Space Agency (ASI) development program, is the flexural traveling wave one. The dynamic equations for the stator and the rotors of the ultrasonic motor are assumed into a differential system, whose equations are coupled by terms that represent interface generalized forces. In order to calculate natural frequencies of the motor-coupled terms of the equations are worked out with respect to the variables of the degrees of freedom. Hence, the mass, damping, and stiffness matrix for the whole system are obtained, then resonance frequencies, depending on the most important running parameters such as axial preload of the motor, are calculated. The results are compared with numerical ones, obtained by a finite element modeling (FEM) model, showing a good agreement.     

Experiences in Teaching Multibody Dynamics

The use of multibody dynamics software in industrial firms is steadily increasing. Engineering curricula often do not include mandatory courses where multibody dynamics is taught. This paper, after a discussion on some teaching needs in this specific cultural area, reports on the experiences matured by the authors when introducing these courses at two Italian universities.     

Egg envelopes of Armadillidium vulgare (Latreille, 1804) (Crustacea,Isopoda Oniscidea): Ultrastructure and lectins binding

The ultrastructural study carried out on (a) oocytes of Armadillidium vulgare during vitellogenesis, (b) mature eggs taken from the ovaries during the parturial moult of the posterior half of the body, and (c) fertilized eggs collected within a few hours of their release into the brood pouch, has clearly demonstrated that before the fertilization the chorion is the only envelope present in the egg of oniscidean isopods. In the mature eggs, the chorion appears as a uniformly electron‐dense lamina, about 0.4–0.5 µm thick, which does not show any specialized area. A second envelope, described by other authors as vitelline envelope, is formed above the oolemma only right after fertilization and appears separated from the chorion by a space full of liquid. The ways in which the genesis of this envelope is realized are not yet clear; it could be interpreted rather as a fertilization membrane. The investigations carried out with the aid of a battery of FITC‐lectins have highlighted the presence at the chorion surface of unfertilized eggs of various saccharide residues distributed in uniform way. No significant change was observed in the pattern of lectins binding to the chorion of eggs taken from the brood pouch, thus demonstrating how, after the fertilization, no significant rearrangement in the distribution of saccharide residues present on the egg surface occurs in A. vulgare. The ways in which, therefore, the recognition, the binding and the entry of the peculiar sperm of oniscidean isopods into the egg occur, still remain all to be deciphered. Microsc. Res. Tech. 79:792–798, 2016. © 2016 Wiley Periodicals, Inc.     

Using entering reading comprehension performance as a predictor of performance in college classes.

In the reported study, we tested the hypothesis that the comprehension of reading material drawn from a college course could be used to predict learning performance in that course. Students enrolled in an educational psychology course or a business statistics course took at the beginning of the semester comprehension tests that were based on both psychology and statistics texts. The reading comprehension scores were related to examination performance in the courses and to overall college grade point average (GPA). For comparison purposes, Scholastic Aptitude Test scores were related to the same variables. The results revealed that course-relevant reading comprehension performance (i.e., psychology in the psychology course, statistics in the statistics course) was a significant predictor of course performance but not of GPA. The results are discussed in terms of a model of comprehension that contains general and specific factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Soft analyzers for a sulfur recovery unit

This work deals with the design and implementation of soft sensors for a Sulfur Recovery Unit (SRU) in a refinery. Soft sensors are mathematical models able to emulate the behavior of existing sensors on the basis of available measurements. In this application, they are used when sensors are taken off for maintenance. The measurements considered in this work are very important for the environmental impact of the refinery, as they regard pollutant acid gas emissions. Four strategies have been implemented and compared: Multi-Layer Perceptrons (MLP) and Radial Basis Function neural networks, Neuro-Fuzzy networks and nonlinear Least-Squares (LSQ) fitting. The best performance is given by MLP neural networks and nonlinear LSQ, all of them implementing Nonlinear Moving Average models. The best soft sensors have been installed on the on-line distributed control systems of the refinery and on-line performance is highly satisfactory.