ABSTRACT
Due to the advent of IoT and the increasing interest of billions of Internet users towards video contents, a huge multimedia flows has been generated, and as a consequence, a massive load is applied on the underlying core network. This change can affect the network stability and lead to potential performance degradation (such as congestion and delays). This is because multimedia flows are hungry in bandwidth, and also the classical routing protocols currently used in IoT core network (like OSPF) are not adapted yet to support the heavy and the large scale of multimedia traffics with a good quality of service (QoS). In this paper, we introduce the multicommodity-based routing by proposing two contributions, Maximum Concurrent Flow Protocol (MCFPr) and Cache-based Maximum Concurrent Flow (C-MCF). They are conceived based on the Maximum Concurrent Flow approach in order to optimize the routing of multimedia data in the backbone of IoT networks. Both contributions are studied and compared with the state-of-art approaches under different scenarios showing good results, especially in the number of data packets sent (improvement by 50%), and in the transmission time (50% faster compared to the majority), which makes them promising solutions for a rapid and efficient routing in IoT core networks.
ABSTRACT
BACKGROUND: Brain perfusion is most likely to be impaired in border zone regions, and clearance of emboli will be most impaired in these regions of least blood flow. Severe occlusive disease of the internal carotid artery causes both embolization and decreased perfusion as well as some cardiac diseases that cause microembolization. OBJECTIVES: To differentiate between hypoperfusion and microemboli as etiology of acute ischemic stroke in watershed zone. SUBJECT AND METHODS: Fifty patients of acute ischemic stroke in watershed zones were recruited within 7 days from stroke onset. Methods used were transcranial Doppler (TCD) monitoring for the intracranial vessels to detect microembolic signals and magnetic resonance imaging (MRI) perfusion image to detect hypoperfusion signs. RESULTS: We detect embolic causes of watershed infarction (WSI) by using TCD with 61.1% sensitivity and 84.4% specificity and hypoperfusion causes of WSI by using MRI perfusion studies with 94.9% sensitivity and 54.5% specificity. CONCLUSION: We detected the etiology of WSI, either embolic by using TCD or hypoperfusion by using MRI perfusion. The embolic causes of WSI usually cause external or mixed WSI, and hypoperfusion causes of WSI cause internal WSI.
ABSTRACT
INTRODUCTION: Neurological complications occur in a large number of patients with chronic hepatitis C virus (HCV) infection and range from peripheral neuropathy to cognitive impairment. We studied the association between neuropathy and HCV-related chronic liver disease. METHOD: Fifty patients with HCV-related chronic liver disease were enrolled in this prospective case-control study. Patients were classified into two groups: mild and severe corresponding to a model for end-stage liver disease (MELD) score <14 and a MELD score >14, respectively. Complete neurological examination and nerve conduction studies have been done for all patients. All patients in addition to 25 healthy control subjects were tested for their serum B12 levels. RESULTS: Twenty-two percent of patients had sensory abnormality, 18 % had motor abnormality, while 10 % had both sensory and motor abnormalities. Autonomic function tests and nerve conduction studies revealed that 23 patients (46 %) had evidence of neuropathy and 10 patients (20 %) had both peripheral and autonomic neuropathy. Neuropathies were not related to the severity of the liver disease. Serum B12 level had a very wide range among patients with no relation between its level and neuropathy. Vitamin B12 level was significantly and directly correlated to MELD score and age. CONCLUSION: Peripheral and autonomic neuropathy has high prevalence in patients with HCV-related chronic liver disease. On the other hand, vitamin B12 level is high in those patients and there is no role for vitamin B12 in the liver cirrhosis-related neuropathy.
