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International audience; In this paper, we propose a Hybrid Multi-Channel Multi-hop Medium Access Control (HMM-MAC) meeting the safety and non-safety requirements in Vehicular Ad-hoc Networks when no infrastructure is present (V2V communication) with only a single transceiver at each vehicle. The simulation results showed that our scheme could achieve a higher delivery ratio of road safety messages and a high probability to select a free transmission channel in a certain region and during a certain time

To survey the situation of traumatic spinal cord injuries (SCI) in Jordan and for a future nationwide epidemiological survey, a retrospective study was conducted at the Royal Jordanian Rehabilitation Centre (RJRC) King Hussein Medical Centre (KHMC) Amman-Jordan, where all traumatic cases within this centre in addition to a few nontraumatic spinal injury patients are referred to the spinal unit which has a capacity of 30 beds. 151 traumatic SCI patients who were admitted to the spinal unit at RJRC during the period January 1988 to December 1993 were reviewed. The estimated annual incidence was 18 per million population. The majority were predominantly males (85.4%) the male/female ratio was 5.8:1. The mean age at the time of injury was 33 being 30.9 years for males and 34.8 years for females. There were 68% (n = 103) with paraplegia and 32% (n = 48) with tetraplegia (Frankel A-D). The commonest aetiology was motor vehicle accidents (44.4% n = 67), next came bullet injuries (25.8% n = 39), followed by accidental falls (21.2% n = 32). Other causes of SCI, and also the importance of preventive measures are discussed. Language: en

This work presents the GPRS simulation in NS for WLAN and GPRS integration. The interoperability between the access network WLAN and GPRS is of high importance in order to provide seamless mobility of the mobile user roaming between different access networks. Many architectures were proposed to ensure this interoperability relying on MIP as the mobility protocol for vertical handoff providing seamless roaming between different access technologies. The end-to-end performance during handover from WLAN to GPRS and vice-versa is studied.

The rate of progressive joint space narrowing in the contralateral hip after total hip arthroplasty (THA) for osteoarthritis (OA) and the factors which may predispose patients to more aggressive joint space narrowing remain undefined. The current study sought to evaluate the rate and pattern of, and risk factors for, progressive joint space narrowing in the contralateral hip after THA for OA.Each patient who underwent THA for OA in 1984-1985 was followed up longitudinally, and annual anteroposterior (AP) pelvis radiographs were obtained. The radiographic joint space width (JSW) of each contralateral hip joint was quantified, and the rates of JSW narrowing were determined. Evaluation of potential risk factors for accelerated progression of joint space narrowing included age, sex, side of surgery, weight, height, body mass index (BMI), hip pain, etiology of OA, and Kellgren/Lawrence radiographic grade.Ninety-nine patients and 619 AP pelvis radiographs were evaluated. The median initial JSW was 3.48 mm (interquartile range 1.55). JSW declined in a linear manner at a median rate of 0.10 mm/year. The rate of decline between baseline and followup in 20 months was predictive of the overall slope. Two subpopulations were identified. Eighty-five percent of patients maintained a slow decline in JSW (or =0.2 mm/year), and 15% exhibited an accelerated decline in JSW (0.2 mm/year). Kellgren/ Lawrence radiographic gradeor =2 and a diagnosis of primary OA were each associated with a more rapid decline in JSW (P = 0.006 and P = 0.02, respectively). Initial JSW, age, sex, weight, height, BMI, and hip pain were not risk factors for rapid decline in JSW.Radiographic hip JSW may be reliably quantified and followed up longitudinally using standard AP radiographs. Progression of JSW narrowing in the contralateral hip after THA for OA proceeds in a linear manner over several years. A subpopulation of patients with accelerated narrowing of contralateral JSW may be identified within 20 months, and may represent a suitable population with which to assess the potential efficacy of new disease-modifying agents.

The crystal structures of 1,4-diethynylbenzene 1 and 1,3,5-triethynylbenzene 2 show similar packing principles with CH...p (triple bond)-zigzag networks; surprisingly, the packing motif of ethynylbenzene 3 is quite different. Crystallog. data and at. coordinates are given.

Objective The rate of progressive joint space narrowing in the contralateral hip after total hip arthroplasty (THA) for osteoarthritis (OA) and the factors which may predispose patients to more aggressive joint space narrowing remain undefined. The current study sought to evaluate the rate and pattern of, and risk factors for, progressive joint space narrowing in the contralateral hip after THA for OA. Methods Each patient who underwent THA for OA in 1984–1985 was followed up longitudinally, and annual anteroposterior (AP) pelvis radiographs were obtained. The radiographic joint space width (JSW) of each contralateral hip joint was quantified, and the rates of JSW narrowing were determined. Evaluation of potential risk factors for accelerated progression of joint space narrowing included age, sex, side of surgery, weight, height, body mass index (BMI), hip pain, etiology of OA, and Kellgren/Lawrence radiographic grade. Results Ninety-nine patients and 619 AP pelvis radiographs were evaluated. The median initial JSW was 3.48 mm (interquartile range 1.55). JSW declined in a linear manner at a median rate of 0.10 mm/year. The rate of decline between baseline and followup in 20 months was predictive of the overall slope. Two subpopulations were identified. Eighty-five percent of patients maintained a slow decline in JSW (≤0.2 mm/year), and 15% exhibited an accelerated decline in JSW (>0.2 mm/year). Kellgren/Lawrence radiographic grade ≥2 and a diagnosis of primary OA were each associated with a more rapid decline in JSW (P = 0.006 and P = 0.02, respectively). Initial JSW, age, sex, weight, height, BMI, and hip pain were not risk factors for rapid decline in JSW. Conclusion Radiographic hip JSW may be reliably quantified and followed up longitudinally using standard AP radiographs. Progression of JSW narrowing in the contralateral hip after THA for OA proceeds in a linear manner over several years. A subpopulation of patients with accelerated narrowing of contralateral JSW may be identified within 20 months, and may represent a suitable population with which to assess the potential efficacy of new disease-modifying agents.

L'adaptation d'une impédance de charge à un générateur HF est effectuée par l'emploi d'un système automatique à capteurs amont/aval, piloté par un micro-ordinateur qui indique l'impédance de charge, calcule la valeur des éléments variables du quadripôle d'adaptation et vérifie la qualité de l'adaptation.