On Multi-Domain Connection Admission Control in the EuQoS System

This paper describes an approach for performing a Connection Admission Control (CAC) function that is investigated in the EuQoS system designed for providing QoS over a heterogeneous, multi-domain network. The CAC plays a key role in QoS provision since it limits the volume of submitted traffic and, in this way, guarantees the assumed QoS level for transferred packet flows. The CAC algorithms are associated with specific end-to-end Classes of Service (CoS). In the EuQoS system we define a set of CoSs that are supported by the system. Each CoS is designed for transferring data corresponding to given type of applications (as voice, video-conference, high data transfer, video on demand etc.) with assuring appropriate QoS level, expressed in the form of packet loss ratio, mean packet transfer delay and packet delay variation. To cope with multi- domain network, the CAC is performed in many places in the EuQoS system. More specifically, the CAC is distributed horizontally, among the different QoS domains, as well as vertically, among Network Technology Independent (NTI) and Network Technology Dependent (NTD) infrastructures developed by EuQoS. NTD infrastructure allows CAC to interact with the underlying networks, such as WiFi, UMTS, LAN/Ethernet, xDSL, Satellite, and IP

Paralysing lumbar disc herniation: a surgical emergency? Reflexion about a series of 24 patients and literature data

BACKGROUND AND PURPOSE: Paralysing lumbar disc herniation (LDH): what and when to do? Few studies have analyzed the optimal timing of surgery in case of paralysing LDH. METHODS: Twenty-four charts were retrospectively reviewed of patients suffering of LDH with severe motor deficit. RESULTS: There were 16 men and eight women. Mean age was 45.1 years. Seventeen patients suffered of lumbar pain, 15 of radicular pain and all of a severe motor deficit, implying mostly the ankle flexion (17 patients). LDH was most frequently located at L4/L5 or L5/S1 level. Surgery was proposed to all patients at the end of the consultation. Nine patients were operated within 48 hours. The mean interval between onset of motor deficit and operation was 20 days. The statistical analysis did not reveal any significant difference among different prognostic factors between the 17 patients with good motor recovery and the seven patients with poor motor recovery. In particular the operative delay did not appear to influence the degree of motor recovery. Literature review on paralysing LDH provides five published series since 1996, including 28 to 116 patients. Two series, including the single prospective one, conclude that the degree of recovery of motor function is inversely related to the degree and duration of motor deficit. CONCLUSIONS: Our retrospective series of 24 operated paralysing LDH did not reveal any prognostic factor for motor recovery. There is no evidence based medicine data in the literature about the optimal timing of decompressive surgery. A relative consensus exists among spine surgeons for paralysing LDH: since operative indication is obvious, surgery should be done as soon as possible