On Exponents Of Primitive Graphs

A connected gaph G is primitive provided there exists a positive integerk such that for each pair of vertices u and v in G there is a walk of lengtht that connects u and v. The smallest of such positive integers k is calledthe exponent of G and is denoted by exp(G). In this paper, we give a newbound on exponent of primitive graphs G in terms of the length of thesmallest cycle of G. We show that the new bound is sharp andgeneralizes the bounds given by Shao and Liu et. al

The Exponent Set of Complete Asymmetric 2-digraphs

A 2-digraph is a digraph whose each ofits arcs is colored by either redor blue. The exponent ofa 2-digraphD is the smallest positive integerh + k over all possible nonnegative integers h and k such that for eachpair of vertices u and v in D there is a walk from u to v consisting of hred arcs and k blue arcs. In this paper, we show that for n > 5 theexponent set of complete asymmetic 2-digraphs on n vertices is Eo :{2,3,4}

Automated verification of flight software. User's manual

(Automated Verification of Flight Software), a collection of tools for analyzing source programs written in FORTRAN and AED is documented. The quality and the reliability of flight software are improved by: (1) indented listings of source programs, (2) static analysis to detect inconsistencies in the use of variables and parameters, (3) automated documentation, (4) instrumentation of source code, (5) retesting guidance, (6) analysis of assertions, (7) symbolic execution, (8) generation of verification conditions, and (9) simplification of verification conditions. Use of AVFS in the verification of flight software is described

Epidemiological study of bladder cancer in the university Hospital of Tlemcen

Background: Bladder cancer is diagnosed or treated worldwide in 2.7 million people each year (4%), and is the second urological cancer after prostate cancer (7th cancer localization in the world), 3% of cancer deaths, 75% of which are in men, most of those tumors appears after the age of 60.  The objective of this study is to establish the epidemiological, clinical, histological, and therapeutic profiles of bladder cancer in this population. Methods: This work deals with a retrospective study of all 104 patients treated at the Medical Oncology Department of the Tlemcen University Hospital for bladder cancer from January 2011 to December 2018. The sex ratio (M/W) is 12. The average age is about 67. The concept of smoking found in 81 patients, weaned in 42 of them. The average duration of change is 24 months [1-348]. Hematuria was the main reason for consultation (90/104). The disease has been diagnosed at a localized stage (19), locally advanced (7), localized or locally advanced (18), and metastatic (54). The metastatic lesions were pulmonary, in the liver, in the bone, and peritoneal.  Patients benefited from transurethral bladder resection. The histological types were 96% urothelial carcinoma, 1% sarcoma, and 3% of other cancer types. 31 patients received surgery: curative type in 24 patients, and palliative in 7 patients. Twenty-one patients received radiation therapy: external type in 13 patients, in conjunction with chemotherapy (RCC) in 2 patients, analgal in 5 patients. Fifty-eight patients received treatment with chemotherapy, adjuvant in 10 patients, palliative in 24 patients, neoadjuvant in 22 patients, and combination with radiotherapy in 2 patients. Results: In theory, bladder cancer is an elderly disease and about 80% of patients with bladder cancer were over the age of 60.  The male predominance observed in our study reported by several authors around the world (about 90% of male patients). Smoking is the major risk factor for bladder cancer (80% of patients are smokers).  The average age of discovery of the disease in our series is 67 years, compared to other countries (e.g., France, 70 years). More than 80% of patients see blood in their "hematuria" urine (the main reason for consultation with a rate of 86%. Urothelial-type tumors are the most common, and 96% of bladder tumor cases are urothelial. Conclusion: At the end of these results, we find that bladder cancer is a typical localization especially in male smokers, usually occurs after the age of 60, and marked by the onset of hematuria, most often discovered at a late stage, hence the interest in raising awareness against tobacco poisoning with the development of screening methods, in order to ensure better therapeutic management of our sick

INFLUENCE OF AGING ON THE DYNAMICS OF LATERAL STABILIZATION IN WALKING, IN DIFFERENT EXPERIHENTAL CONDITIONS RELATED TO SHOE WEARING AND FLOOR HARDNESS

Review of biomechanics literature on the influence of aging on the locomotor system indicates that safe load bearing as well as deformation sustaining capabilities of biological tissues decrease with age. Postural studies of older populations have di8closed more body sway than in younger age groups and have often associated loss of balance with locomotion problems of old age people. On the other hand, biomechanical studies of walking and running have already demonstrated t h a t wearing shoes and shoe characteristics can play an important r o l e in shock absorption. However the influence of aging on the dynamic of lateral stabilization in walking in relationship with shoe wearing and floor hardness has received very little attention. Such a biomechanical approach t o locomotion is becoming more important since more and more older people are involved in sport and fitness activities including some form of locomotion. The present study has been undertaken in order to investigate the influence of aging together with shoe wearing and floor hardness on some of the main components, of lateral stabilization in walking, namely the lateral forces, the lateral impulse and the lateral deviation o f the center of pressure. Three groups of 15 physically active male subjects (17-22, 40-45 and 65-70 years old) were instructed to walk on a tri-dimensional force platform a t a predetermined pace set with a metronome;. Experimental conditions included walking barefoot and with regular shoes, on a hard and a softer surfaces. Kinetic data were recorded on the 5th, 25th, 50th, 100th and 500th steps for each condition, with the use of the computerized . Ariel Performance Analysis System. Analysis of the results disclosed important differences between the age groups in all three experimental parameters. Lower lateral forces exerted by the older age group lead t o the hypothesis of a different stabilization strategy based on energy saving. Findings were also discussed in relationship with the lateral stabilization process and applications were made to sport and fitness activities a s well a s the daily living situations

Endogenous Retroviruses: Thierry Heidmann wins the 2009 Retrovirology prize

Thierry Heidmann wins the 2009 Retrovirology prize

Enhanced Dielectric Constant for Efficient Electromagnetic Shielding Based on Carbon-Nanotube-Added Styrene Acrylic Emulsion Based Composite

An efficient electromagnetic shielding composite based on multiwalled carbon nanotubes (MWCNTs)-filled styrene acrylic emulsion-based polymer has been prepared in a water-based system. The MWCNTs were demonstrated to have an effect on the dielectric constants, which effectively enhance electromagnetic shielding efficiency (SE) of the composites. A low conductivity threshold of 0.23 wt% can be obtained. An EMI SE of ~28 dB was achieved for 20 wt% MWCNTs. The AC conductivity (σac) of the composites, deduced from imaginary permittivity, was used to estimate the SE of the composites in X band (8.2–12.4 GHz), showing a good agreement with the measured results

Frequent and Recent Human Acquisition of Simian Foamy Viruses Through Apes' Bites in Central Africa

Human infection by simian foamy viruses (SFV) can be acquired by persons occupationally exposed to non-human primates (NHP) or in natural settings. This study aimed at getting better knowledge on SFV transmission dynamics, risk factors for such a zoonotic infection and, searching for intra-familial dissemination and the level of peripheral blood (pro)viral loads in infected individuals. We studied 1,321 people from the general adult population (mean age 49 yrs, 640 women and 681 men) and 198 individuals, mostly men, all of whom had encountered a NHP with a resulting bite or scratch. All of these, either Pygmies (436) or Bantus (1085) live in villages in South Cameroon. A specific SFV Western blot was used and two nested PCRs (polymerase, and LTR) were done on all the positive/borderline samples by serology. In the general population, 2/1,321 (0.2%) persons were found to be infected. In the second group, 37/198 (18.6%) persons were SFV positive. They were mostly infected by apes (37/39) FV (mainly gorilla). Infection by monkey FV was less frequent (2/39). The viral origin of the amplified sequences matched with the history reported by the hunters, most of which (83%) are aged 20 to 40 years and acquired the infection during the last twenty years. The (pro)viral load in 33 individuals infected by a gorilla FV was quite low (<1 to 145 copies per 105 cells) in the peripheral blood leucocytes. Of the 30 wives and 12 children from families of FV infected persons, only one woman was seropositive in WB without subsequent viral DNA amplification. We demonstrate a high level of recent transmission of SFVs to humans in natural settings specifically following severe gorilla bites during hunting activities. The virus was found to persist over several years, with low SFV loads in infected persons. Secondary transmission remains an open question