Cross-layer Resource Allocation Scheme for Multi-band High Rate UWB Systems

In this paper, we investigate the use of a cross-layer allocation mechanism for the high-rate ultra-wideband (UWB) systems. The aim of this paper is twofold. First, through the cross-layer approach that provides a new service differentiation approach to the fully distributed UWB systems, we support traffic with quality of service (QoS) guarantee in a multi-user context. Second, we exploit the effective SINR method that represents the characteristics of multiple sub-carrier SINRs in the multi-band WiMedia solution proposed for UWB systems, in order to provide the channel state information needed for the multi-user sub-band allocation. This new approach improves the system performance and optimizes the spectrum utilization with a low cost data exchange between the different users while guaranteeing the required QoS. In addition, this new approach solves the problem of the cohabitation of more than three users in the same WiMedia channel

An Iron Rod Impaling the Axilla with Major Vascular Injury: a Case Report

Background and Objective Impalement injury is an uncommon cause of vascular trauma; however such spectacular injuries are associated with a high mortality rate and need to be managed by a multidisciplinary medical team at tertiary trauma center. The reported literature is scarce and no available well-written guidelines so that the management plan should be individualized and tailored to the situation at hand. The objective of this case study is to update our experience and protocols to maximize the clinical outcome and minimize the fatality rate of such challenging life-threatening events. Methods It is a case report of a 31-year construction worker that sustained an impalement injury when he fell down on an iron rod traversing his left axilla; he was transferred to our hospital with a 90- cm rod in situ. The patient was rapidly resuscitated and investigated preparing him for prompt surgical intervention; the metallic rod was extracted at the theater gently under direct vision with gushing out of blood due to the major vascular injury that was immediately controlled, followed by proper washout and thorough debridement of all devitalized tissues. Then, exploration of the neurovascular bundle at the axilla showed an injury of the axillary vein for which primary repair was successfully performed, but fortunately the axillary artery and brachial plexus were intact. Results: The patient had uneventful postoperative course with no complications and his limb was saved; he is being followed for 14 months up till now. Conclusion Major vascular injuries caused by impalement accidents are rare events; however they are challenging and may be fatal. Our current conclusions and recommendations are deficient and we need more updated research work to improve the outcome and decrease the number of deaths. We can acknowledge the end points which include careful and rapid transportation of the patient to a tertiary trauma centre with the impaled objects in situ that should be extracted only at the theater, proper diagnosis and prompt surgical intervention by a multidisciplinary team

Organic Agriculture in Saudi Arabia - Sector Study 2012

This publication compiles the facts and figures of the organic sector in Saudi Arabia. It is a valuable resource for local stakeholders and interested trading companies. The publication is resulting from a collaboration between GIZ (Deutsche Gesellschaft für Internationale Zusammenarbeit) and FiBL together with its partners of the Saudi Ministry of Agriculture and Saudi Organic Farming Association (SOFA)

Review of Security and Privacy Scheme for Vehicular Ad Hoc Networks (VANETs)

Vehicles in a vehicular ad-hoc network (VANET) broadcast information about the driving environment in the road. Due to the open-access environment, this means that the VANET is susceptible to security and privacy issues. However, none of the related works satisfies all security and privacy requirements. Besides, their proposed has huge overhead in terms of computation and communication. The present paper is a provide a thorough background on VANETs and their entities; different security attacks; and all requirements of the privacy and security for VANETs. This paper may serve as a guide and reference for VANETs in the design and implementation of any new techniques for protection and privacy

The effect of banana peels supplemented diet on acute liver failure rats

AbstractPeel of vegetables and fruits are of the most important part that helps in protecting the body from diseases, getting rid of the free radicals, as they contain vitamins and minerals which are antioxidant, in addition to phenols. Previous studies have proved the existence of vitamin C, E, and B6 in banana peels, especially vitamin C that can act as an antioxidant.The present study was performed to examine the effect of fresh and dried banana peels consumption on liver function (albumin, GPT, GOT, LDH, GGT and ALP) and lipid profiles cholesterol, triglycerides, low-density lipoprotein (LDL), high-density lipoprotein (HDL) and very low-density lipoprotein (VLDL) on acute liver failure rats induced by carbon tetrachloride. The chemical constituents, vitamins, minerals and fiber were determined for the tested fresh and dried banana peels.This work was carried out on 40 adult male white albino rats randomly classified into eight groups (each of 5 rats). The first group was fed on basal diet as a “negative control”. The other seven groups were injected by carbon tetrachloride to induce liver failure. The second group fed on basal diet as acute liver failure rat’s untreated “positive control”, the third into five groups fed on basal diet containing 5%, 10% and 15% fresh banana peels while the six into eight groups fed on basal diet containing of 5%, 10% and 15% dried banana peels for a period of four consecutive weeks.Results revealed that all acute liver failure groups administrated with different levels of fresh banana peels (5%, 10% and 15%) had significant decrease in liver function, total cholesterol, triglycerides, LDL-c and VLDL-c cholesterol comparing with the positive control group. On the other hand, significant increase in HDL-c was recorded in all acute liver failure groups administrated with dried banana peels 5% and 10% comparing with control positive group. It was suggested that, consumption of fresh and dried banana peels may modify the risk of acute liver failure patients

Proposal: An Efficient Security and Privacy Scheme based on Elliptic Curve Cryptography (ECC) for Vehicular Ad hoc Network (VANET)

Vehicles in a vehicular ad-hoc network (VANET) broadcast information about the driving environment in the road. Due to the open-access environment, this means that the VANET is susceptible to security and privacy issues. However, none of the related works satisfies all security and privacy requirements. Besides, their proposed has huge overhead in terms of computation and communication. To address the above issues, we will propose the security and privacy scheme based on Elliptic Curve Cryptography (ECC) and one secure hash function. Hence the reliability of each message being signed and checked has been improved. The main aim of this work is to satisfy all aspect requirements of security and privacy and reduce the computational complexity of the system

CROSS-LAYER RESOURCE ALLOCATION SCHEME UNDER HETEROGENEOUS CONSTRAINTS FOR NEXT GENERATION HIGH RATE WPAN

International audienceIn the next generation wireless networks, the growing demand for new wireless applications is accompanied with high expectations for better quality of service (QoS) fulfillment especially for multimedia applications. Furthermore, the coexistence of future unlicensed users with existing licensed users is becoming a challenging task in next generation communication systems to overcome the underutilization of the spectrum. A QoS and interference aware resource allocation is thus of special interest in order to respond to the heterogeneous constraints of the next generation networks. In this work, we address the issue of resource allocation under heterogeneous constraints for unlicensed multi-band ultra-wideband (UWB) systems in the context of Future Home Networks, i.e. WPAN. The problem is first studied analytically using a heterogeneous constrained optimization problem formulation. After studying the characteristics of the optimal solution, we propose a low-complexity suboptimal algorithm based on a cross-layer approach that combines information provided by the PHY and MAC layers. While the PHY layer is responsible for providing the channel quality of the unlicensed UWB users as well as their interference power that they cause on licensed users, the MAC layer is responsible for classifying the unlicensed users using a two-class based approach that guarantees for multimedia services a high-priority level compared to other services. Combined in an efficient and simple way, the PHY and MAC information present the key elements of the aimed resource allocation. Simulation results demonstrate that the proposed scheme provides a good tradeoff between the QoS satisfaction of the unlicensed applications with hard QoS requirements and the limitation of the interference affecting the licensed users

Multiuser Service Differentiated Spectrum Allocation Scheme for High Rate UWB Systems

International audienceIn this paper, we propose a multiuser spectrum allocation scheme for high-rate UWB systems under QoS requirements. This scheme comes as a solution to the coexistence of multiple users sharing the three sub-bands of the same channel as defined in the WiMedia solution adopted for multiband UWB systems. Indeed, WiMedia solution does not allow more than three users to coexist in the same channel. Based on a constrained multiuser optimization problem, the proposed allocation algorithm allows multiple users to access the medium following a mixed sub-band assignment and priority-based scheduling approach in order to ensure an efficient differentiated spectrum sharing. The resulting time-frequency scheduling algorithm relies on the combination of two main metrics available at PHY and MAC levels: the channel quality of each user provided by the exploitation of the effective SINR method, and the QoS constraint represented by a simple weighting parameter that differentiates between two service classes. Simulation results show the efficiency of the proposed scheme and how it guarantees a good performance level for users having strict QoS requirements