The Performance Evaluation of Adaptive Guard Channel Scheme in Wireless Network

Dynamic Guard Channels (DCG) reduces the dropping and blocking rates in a network. However, most of the existing DGC allocations are not quite efficient because there were consideration for only the Handoff (HO) calls while the New calls (NC) were not considered; this leads to poor Quality of Service (QoS) for NC. Although it is better to give priority to HO calls over NC since the breaking of the connection of an established communicationis more annoying than blocking a NC. Thus, there is need to provide an alternative approach that guarantees an acceptable QoS in terms of both the HC and the NC. This paper presents the performance evaluation of an adaptive guard channel allocation; the scheme made use of two different models (1) guard channel with fuzzy logic (2) guard channel without fuzzy logic. Priority is given to handoff call due to the scarcity of radio spectrum. When all the guard channels have been allocated and the arrival rate of handoff calls keeps on increasing, new set of threshold values would be estimated by fuzzy logic model. Performance metrics are; Call Blocking Rate (CBR), Call Dropping Rate (CDR) and Throughput. Results showed that guard channel with fuzzy logic has the CBR values range from 24.02% to 69.015 and CDR values range from 12.025 to 18.90% while guard channel without fuzzy logic has CBR values range from 28.22% to 75.65% and CDR values range from 19.06% to 36.50%. The scheme proved to be more efficient in congestion control in wireless network

Evaluation of knowledge and practice of pharmaceutical waste disposal in hospitals and pharmacies within Lagos State, Nigeria

Background: Treatment and disposal of waste is a major challenge in most developing countries, including Nigeria. Improper disposal of pharmaceutical waste could have negative impact on the environment and human health as they can cause harmful effects.Objectives: This study assessed the knowledge and practise of healthcare personnel in Lagos State, Nigeria towards pharmaceutical waste disposal.Methods: The study was a cross-sectional descriptive survey carried out using structured questionnaires. Target respondents were healthcare workers involved in the use and disposal of pharmaceutical waste in several hospitals and pharmacies located within the State. Data were analysed using the Statistical Package for Social Sciences (SPSS) version 20 and presented as tables and charts using descriptive and inferential statistics.Results: There was 83.3 % response to the questionnaires. Majority of the respondents (63.07 %) dispose refuse via authorized garbage collectors. The survey indicated that the drainage systems of most hospitals and pharmacies are connected to general drainages while 6.2 % have sewage systems installed. Most of the respondents (68.9 %) indicated that there was no waste disposal method in place for pharmaceutical waste. Knowledge of most appropriate disposal method for pharmaceutical waste amongst most of the respondents was poor (30.85 %).Conclusion: Limited knowledge on pharmaceutical waste disposal was evident amongst the respondents. Hence, the need to enlighten health care personnel on proper pharmaceutical waste disposal methods, so as to avoid associated environmental hazards, is recommended.Keywords: Healthcare workers, Pharmaceuticals, Waste disposal, Environmental, Hazar

The ASOS Surgical Risk Calculator: development and validation of a tool for identifying African surgical patients at risk of severe postoperative complications

Background: The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. Existing risk assessment tools are not valid for use in this population because the pattern of risk for poor outcomes differs from high-income countries. The objective of this study was to derive and validate a simple, preoperative risk stratification tool to identify African surgical patients at risk for in-hospital postoperative mortality and severe complications. Methods: ASOS was a 7-day prospective cohort study of adult patients undergoing surgery in Africa. The ASOS Surgical Risk Calculator was constructed with a multivariable logistic regression model for the outcome of in-hospital mortality and severe postoperative complications. The following preoperative risk factors were entered into the model; age, sex, smoking status, ASA physical status, preoperative chronic comorbid conditions, indication for surgery, urgency, severity, and type of surgery. Results: The model was derived from 8799 patients from 168 African hospitals. The composite outcome of severe postoperative complications and death occurred in 423/8799 (4.8%) patients. The ASOS Surgical Risk Calculator includes the following risk factors: age, ASA physical status, indication for surgery, urgency, severity, and type of surgery. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.805 and good calibration with c-statistic corrected for optimism of 0.784. Conclusions: This simple preoperative risk calculator could be used to identify high-risk surgical patients in African hospitals and facilitate increased postoperative surveillance. © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.Medical Research Council of South Africa gran