Alignment methods for biased multicanonical sampling

The efficiency of the multicanonical procedure can be significantly improved by applying an additional bias to the numerically generated sample space. However, results obtained by biasing in different sampling regions cannot in general be accurately combined, since their relative normalization coefficient is not known precisely. We demonstrate that for overlapping biasing regions a simple iterative procedure can be employed to determine the required coefficients

Heuristic Approach for Scheduling Dependent Real-Time Tasks

Reducing energy consumption is a critical issue in the design of battery-powered real time systems to prolong battery life. With dynamic voltage scaling (DVS) processors, energy consumption can be reduced efficiently by making appropriate decisions on the processor speed/voltage during the scheduling of real time tasks. Scheduling decision is usually based on parameters which are assumed to be crisp. However, in many circumstances the values of these parameters are vague. The vagueness of parameters suggests that to develop a fuzzy logic approach to reduce energy consumption by determining the appropriate supply-voltage/speed of the processor provided that timing constraints are guaranteed. Intensive simulated experiments and qualitative comparisons with the most related literature have been conducted in the context of dependent real-time tasks. Experimental results have shown that the proposed fuzzy scheduler saves more energy and creates feasible schedules for real time tasks. It also considers tasks priorities which cause higher system utilization and lower deadline miss time

An Efficient Cache Organization for On-Chip Multiprocessor Networks

To meet the growing computation-intensive applications and the needs of low-power, high-performance systems, the number of computing resources in single-chip has enormously increased. By adding many computing resources to build a system in System-on-Chip, its interconnection between each other becomes another challenging issue. In most System-on-Chip applications, a shared bus interconnection which needs an arbitration logic to serialize several bus access requests, is adopted to communicate with each integrated processing unit because of its low-cost and simple control characteristics. This paper focuses on the interconnection design issues of area, power and performance of chip multi-processors with shared cache memory. It shows that having shared cache memory contributes to the performance improvement, however, typical interconnection between cores and the shared cache using crossbar occupies most of the chip area, consumes a lot of power and does not scale efficiently with increased number of cores. New interconnection mechanisms are needed to address these issues. This paper proposes an architectural paradigm in an attempt to gain the advantages of having shared cache with the avoidance of penalty imposed by the crossbar interconnect. The proposed architecture achieves smaller area occupation allowing more space to add additional cache memory. It also reduces power consumption compared to the existing crossbar architecture. Furthermore, the paper presents a modified cache coherence algorithm called Tuned-MESI. It is based on the typical MESI cache coherence algorithm however it is tuned and tailored for the suggested architecture. The achieved results of the conducted simulated experiments show that the developed architecture produces less broadcast operations compared to the typical algorithm

Probable abdominal compartment syndrome in an 8-month-old child

An 8-month-old, male child was brought to the emergency department (ED) by his parents with difficulty of breathing. The child developed shortness of breath for one day with cough, but he had no fever. According to the parents, they did not notice the abdominal distension. The child was born prematurely at 25 weeks of gestation and stayed in the neonatal intensive care unit (NICU) for 2 months. Otherwise, he was healthy with minor repeated chest infections and bronchiolitis. In triage, his vital signs were as follows: heart rate:180 beats/min; respiratory rate: 35 breaths/min; temperature: 35± C; oxygen saturation: 70%; and his blood pressure was undetected. The child was immediately transferred to the resuscitation room. The primary survey showed that the patient was comatose with a Glasgow coma scale of 3/15, the pupils were brisk with an unstable airway, and there was bilateral diminished air entry. The oxygen saturation did not improve despite assisted ventilation using an Ambu bag. The central and peripheral pulsation was weak with a delayedcapillary refill, and the blood glucose level was 9 mmol/L. The abdomen was hugely distended and rigid with minimal rectal bleeding. The patient was immediately intubated and connected to mechanical ventilation with subsequent rising of his oxygen saturation to 100%. A plain chest X-ray examination followed the patient’s intubation. Intravenous access was obtained followed by administration of normal saline (20 ml/kg) with subsequent elevation of the blood pressure (82/50mmHg) and decrease in heart rate (160 beats/minute). Initial arterial blood gases (ABG) analysis after intubation showed pH: 6.6; PaCO2 >150 mmHg; PaO2: 100 mmHg; HCO3: 10mEq/L; and lactic acid: 9 mg/dL. Therefore, a bolus of sodium bicarbonate was given, intravenously. Ventilator parameters were set at the maximum limits to wash out carbon dioxide. Repeated ABG analysis showed pH: 6.7; PaCO2: 135 mmHg; PaO2: 150 mmHg; HCO3: 17 mEq/L; and lactic acid: 6.5 mg/dL. Immediate bedside abdominal X-ray and ultrasonography were carried out to rule out intussusception. The child remained critically ill and unstable with fluctuating vital signs. Despite high ventilator parameters and gasgastric tube suction, the child showed no improvement in the respiratory parameters. The child was then transferred to the operation theatre for decompression laparotomy, which showed small bowel (ileum) ischemia. After surgical decompression, the respiratory parameters improved, and the ventilatorparameters were set back to normal settings for the patient’s age and weight. Unfortunately, the child remained critically ill. Then, he developed sepsis and multiple systems organ failure and died after 2 days

Electronic Pre-Compensation of Intra-Channel Nonlinearity in a 10Gb/s Optical Transmission System

We introduce several new algorithms for compensating intra channel nonlinearities in lightwave systems through electronic predistortion. These were optimized and modeled assuming realistic conditions at Nortel and were found to be insensitive to normal environmental and design fluctuations in commercial systems. We also present an upper bound on system performance that agrees well with measured results

COVID-19 in Sudan: Will the mitigation Efforts win against the Virus?

Background: The COVID-19 pandemic has hit hard both the affluent and poor countries. The objective of this article is to highlight the efforts of the Ministry of Health in Sudan in mitigating the pandemic and reflecting on counteracting factors. Methods: We traced the reports and plans of the Federal Ministry of Health and looked at the models projecting the pandemic in Sudan. Results: The fundamental plan of the government of Sudan to cope up with the pandemic included the control of the source of infection, blocking transmission, and preventing the spread. The response mechanism had a multi-sector approach with involvement of government, civil society organizations, and non-governmental organizations (NGOs). The action plans involved protocols for COVID-19 diagnosis and treatment, surveillance, epidemiological investigation, and management of case contacts. However, several factors continued to jeopardize the mitigation efforts of these plans. At the time of writing this article (at the end of the May 2020), there were about 4,000 confirmed cases, 300 recoveries, and 170 deaths. Although these numbers are below the projected numbers in many proposed models, in the light of the limited testing capacity, case identification and contact tracing, the exact situation might not be ascertained. Conclusion: Sudan has prepared a national plan to prevent and contain COVID19 pandemic. However, tremendous challenges are opposing these efforts. The poor health infrastructure, fragility of the health system, and the economic crisis are the major obstructions

Adaptive co-operative mobile robots

This work proposes a biologically inspired collective behaviour for a team of co-operating robots. Collective behaviour is achieved by controlling the local interactions among a set of identical mobile robots, each robot performing a set of simple behaviours in order to realise group goals. A modification of the subsumption architecture is proposed for implementing control of individual robots. This architecture is adopted because it is computationally inexpensive and potentially suitable for low-level reactive and reflexive behaviours. In this scenario, the individual behaviours of the robots have different aims, which may cause conflict. To address this issue, a fuzzy logic-based approach for multiple behaviour coordination within each robot is proposed. The work also focuses on the development of intelligent multi-agent robot teams capable of acting autonomously and of collaborating in a dynamic environment to achieve team objectives. A knowledge-based software architecture is proposed that enables these robots to select co-operative behaviours and to adapt their performance during the specified time of the mission. These abilities are important because of uncertainties in the environmental conditions and because of possible functional failures in some team members. Improvement in team performance is achieved by updating the control of the robots based on knowledge acquired on-line. This architecture is implemented in a simulated team of mobile robots performing a proof-of-concept collaborative task. The results show a significant improvement in overall group performance and the robot team is able to achieve adaptive cooperative control despite dynamic changes in the environment and variation in the capabilities of the team members. Finally, a task involving real mobile robots is undertaken to demonstrate a practical, though simplified, implementation of the proposed collective behaviour

Graduates Perception towards Instructional Methods of Emergency Medicine: Affecting Their Self-confidence in Emergency Departments

Background: Teaching emergencies has the ability to provide medical students with animportant knowledge and skills. In this study, we assessed the perception of Faculty of medicine, University of Gezira graduates regarding instructional methods of emergencies and their performance in emergency departments. Materials and Methods: This is a cross-sectional survey, which was conducted among newly graduated doctors, during their internship rotation. We assessed the graduateperception about instructional methods of teaching EM during medical school and how they deal with emergencies. Likert’s scale of five points was used for assessment of the graduate response. This data was used for a correlation analysis. Result: Ninety three graduates were enrolled. Male doctors’ numbers was 41(44%). Most of the graduated doctors agreed that clinical round and practical session in teaching emergency are useful among 80(86%) and 74(79.6%) of them respectively. Less number of graduated students 45 (48.4%) and 43 (36.6%) agreed that Problem-based learning and Seminar are useful in teaching emergency. Numbers of graduates who feel competence to assess and diagnose patients, request a relevant investigation, and can put a treatment plan and start the managements are 60(68.8%), 76(81.8%) and 61 (65.6%) respectively. Conclusion: There are some strength and weakness in emergency teaching during medical school which affects their self-confidence when dealing with emergencies

Duplex ultrasound for evaluation of deep venous blood flow in fractured lower extremities

Purpose: Early identification of deep venous thrombosis (DVT) in trauma patients would result in an early initiation of treatment, thereby decreasing the frequency of complications. The aim of the current study was to evaluate the role of duplex ultrasound (DUS) in the evaluation of deep venous blood flow in fractured lower extremities to rule out DVT prior to orthopedic surgery. Material and methods: In this prospective study a total of 58 patients (42 males and 16 females; mean age of 51.5 ± 19.5 years) with fractured lower extremities were thoroughly evaluated prior to surgery with respect to medical history, fracture pattern, associated injuries, comorbid conditions, and venous duplex ultrasound (VDUS) findings. Each affected limb was assessed for the presence of DVT using a Sonoline G 60S ultrasound unit. The analysis was performed with the Statistical Package for the Social Sciences (SPSS) version 20. Results: DVT was found in 36 (62.1%) patients with single closed fractures, 9 (15.5%) patients with single opened fractures, 10 (17.2%) patients with multiple closed fractures, and in 3 (5.2%) patients with multiple opened fractures. Sensitivity and specificity of the findings of compressibility and phasicity for DVT detection in patients with fractured lower extremities were 81.25% and 87.50% and 100% and 100% respectively. In addition, the absence of compressibility and phasicity had positive predictive value of 100% and 100% and negative predictive value of 93.75% and 95.65% respectively. Conclusions: US of DVs in the brightness mode (B-mode) with compression maneuvers should be the first-line imaging modality for suspected DVT in patients with fractured lower extremities

Duplex ultrasound for evaluation of deep venous blood flow in fractured lower extremities

Purpose: Early identification of deep venous thrombosis (DVT) in trauma patients would result in an early initiation of treatment, thereby decreasing the frequency of complications. The aim of the current study was to evaluate the role of duplex ultrasound (DUS) in the evaluation of deep venous blood flow in fractured lower extremities to rule out DVT prior to orthopedic surgery. Material and methods: In this prospective study a total of 58 patients (42 males and 16 females; mean age of 51.5 ± 19.5 years) with fractured lower extremities were thoroughly evaluated prior to surgery with respect to medical history, fracture pattern, associated injuries, comorbid conditions, and venous duplex ultrasound (VDUS) findings. Each affected limb was assessed for the presence of DVT using a Sonoline G 60S ultrasound unit. The analysis was performed with the Statistical Package for the Social Sciences (SPSS) version 20. Results: DVT was found in 36 (62.1%) patients with single closed fractures, 9 (15.5%) patients with single opened fractures, 10 (17.2%) patients with multiple closed fractures, and in 3 (5.2%) patients with multiple opened fractures. Sensitivity and specificity of the findings of compressibility and phasicity for DVT detection in patients with fractured lower extremities were 81.25% and 87.50% and 100% and 100% respectively. In addition, the absence of compressibility and phasicity had positive predictive value of 100% and 100% and negative predictive value of 93.75% and 95.65% respectively. Conclusions: US of DVs in the brightness mode (B-mode) with compression maneuvers should be the first-line imaging modality for suspected DVT in patients with fractured lower extremities