Degrees and diversity at work

A study of of over 3000 engineers and scientists employed in the United States explored the interplay of levels of education with gender and native versus immigrant status. The results suggest that some of these R&D professionals may be underutilised and perhaps less effective than they could be     

Revascularization of calvarial, mandibular, tibial, and iliac bone grafts in rats

The development of approaches to screening of hospital patients for harmful drinking frequently encounters resistance from both patients and hospital staff. A contributing factor could be the discomfort both feel about talking specifically about drinking. One approach to reducing this discomfort has been to mask concern about alcohol consumption into a general focus on other health and lifestyle issues. One-hundred and eighty-two patients admitted to an emergency department were presented randomly with either a straight alcohol screening questionnaire or a general health and lifestyle questionnaire with alcohol questions embedded amongst items on smoking exercise and diet. The number of returns was equal for both questionnaires which suggests the masked questionnaire does not improve the acceptability of alcohol screening in hospital environments.     

Accelerated iterative methods for finding solutions of nonlinear equations and their dynamical behavior

In this paper, we present a family of optimal, in the sense of Kung–Traub’s conjecture, iterative methods for solving nonlinear equations with eighth-order convergence. Our methods are based on Chun’s fourth-order method. We use the Ostrowski’s efficiency index and several numerical tests in order to compare the new methods with other known eighth-order ones. We also extend this comparison to the dynamical study of the different methods.     

Features of autoimmune hepatitis in primary sclerosing cholangitis: an evaluation of 114 primary sclerosing cholangitis patients according to a scoring system for the diagnosis of autoimmune hepatitis

Overlapping features between primary sclerosing cholangitis (PSC and autoimmune hepatitis (AIH) have previously been noted. To assess systematically similarities between these disorders, we have evaluated 114 PSC patients (36 women; 78 men), all confirmed by endoscopic retrograde cholangiography (ERC), according to a scoring system proposed by The International Autoimmune Hepatitis Group for the diagnosis of AIH. The scoring system attributes positive or negative scores to the parameters sex, ratio of elevation of serum levels of alkaline phosphatase (ALP) vs. aminotransferase, serum levels of immunoglobulins and autoantibodies, viral markers, history of drug and alcohol intake, genetic factors, liver histology, and response to therapy. Two of the PSC patients (2%) obtained scores above 15 before treatment, satisfying the diagnostic criterion of "definite" AIH. Thirty-eight patients (33%) scored between 10 and 15 points and could be classified as "probable" AIH. The serum level of immunoglobulin G (IgG) was elevated in 68 patients (61% of 111 cases tested), and positive titers of antinuclear antibodies (ANA) or smooth muscle antibodies (SMA) were detected in 24 patients (22% of 111 cases tested). Thirty-five of the PSC patients (33% of 105 evaluable biopsy specimens) obtained positive scores for histological features similar to those of AIH, but the total score for histology was in the negative range in 72 patients (69%) because of the presence of biliary changes. The frequent finding of high scores in PSC patients underlines the similarities PSC may have with AIH. A modification of the scoring system, in particular by increasing the negative score for histological biliary changes, would improve its potential to discriminate between AIH and PSC.     

mfERG_LAB: Software for processing multifocal electroretinography signals

The multifocal electroretinography technique consists of performing sectorized light excitation of the retina and capturing the resulting evoked potential. This provides functional localized information about the state of the retinal neurons. Analysis of multifocal electroretinography signals can be used for diagnosing different types of optic neuropathies (glaucomatous, demyelinating and ischemic ethiology). In order to obtain a reliable diagnosis, it is necessary to apply advanced processing algorithms (morphological, frequency and time-frequency analysis, etc.) to the multifocal electroretinography signal. This paper presents a software application developed in MATLAB(?) (MathWorks Inc., MA) designed to perform advanced multifocal electroretinography signal analysis and classification. This intuitive application, mfERG_LAB, is used to plot the signals, apply various algorithms to them and present the data in an appropriate format. The application's computational power and modular structure make it suitable for use in clinical settings as a powerful and innovative diagnostic tool, as well as in research and teaching settings as a means of assessing new algorithms.     

Hydrogen trapping by defects in semiconductors studied by anelastic spectroscopy

We review some results obtained by anelastic spectroscopy on H-related defects in III–V semiconductors. Anelastic measurements on InP lead to the formulation of a model explaining the conversion to the semi-insulating (SI) state. Moreover, in GaAs:Zn an extraordinarily fast relaxation rate has been measured and a possible explanation has been suggested. This results are reviewed and discussed in the light of new experiments on InP:Zn, whose spectrum shows a relaxation process similar to the one in GaAs:Zn.     

Crack initiation,propagation, and arrest in sintering powder aggregates

Cracking during sintering is a common problem in powder processing and is usually caused by constraint that prevents the sintering material from shrinking in one or more directions. Different factors influence sintering-induced cracking, including temperature schedule, packing density, and specimen geometry. Here we use the discrete element method to directly observe the stress distribution and sinter-cracking behavior in edge notched panels sintered under a uniaxial restraint. This geometry allows an easy comparison with traditional fracture mechanics parameters, facilitating analysis of sinter-cracking behavior. We find that cracking caused by self-stress during sintering resembles the growth of creep cracks in fully dense materials. By deriving the constrained densification rate from the appropriate constitutive equations, we discover that linear shrinkage transverse to the loading axis is accelerated by a contribution from the effective Poisson's ratio of a sintering solid. Simulation of different notch geometries and initial relative densities reveals conditions that favor densification and minimize crack growth, alluding to design methods for avoiding cracking in actual sintering processes. We combine the far-field stress and crack length to compute the net section stress, finding that it characterizes the stress profile between the notches and correlates with the sinter-crack growth rate, demonstrating its potential to quantitatively describe sinter-cracking.