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1.
Entropy (Basel) ; 25(9)2023 Aug 22.
Article in English | MEDLINE | ID: mdl-37761544

ABSTRACT

Minimizing a company's operational risk by optimizing the performance of the manufacturing and distribution supply chain is a complex task that involves multiple elements, each with their own supply line constraints. Traditional approaches to optimization often assume determinism as the underlying principle. However, this paper, adopting an entropy approach, emphasizes the significance of subjective and objective uncertainty in achieving optimized decisions by incorporating stochastic fluctuations into the supply chain structure. Stochasticity, representing randomness, quantifies the level of uncertainty or risk involved. In this study, we focus on a processing production plant as a model for a chain of operations and supply chain actions. We consider the stochastically varying production and transportation costs from the site to the plant, as well as from the plant to the customer base. Through stochastic optimization, we demonstrate that the plant producer can benefit from improved financial outcomes by setting higher sale prices while simultaneously lowering optimized production costs. This can be accomplished by selectively choosing producers whose production cost probability density function follows a Pareto distribution. Notably, a lower Pareto exponent yields better supply chain cost optimization predictions. Alternatively, a Gaussian stochastic fluctuation may be proposed as a more suitable choice when trading off optimization and simplicity. Although this may result in slightly less optimal performance, it offers advantages in terms of ease of implementation and computational efficiency.

2.
Int J Health Care Qual Assur ; ahead-of-print(ahead-of-print)2020 Nov 13.
Article in English | MEDLINE | ID: mdl-33179461

ABSTRACT

PURPOSE: The aim of this research study is to develop a queue assessment model to evaluate the inflow of walk-in outpatients in a busy public hospital of an emerging economy, in the absence of appointment systems, and construct a dynamic framework dedicated towards the practical implementation of the proposed model, for continuous monitoring of the queue system. DESIGN/METHODOLOGY/APPROACH: The current study utilizes data envelopment analysis (DEA) to develop a combined queuing-DEA model as applied to evaluate the wait times of patients, within different stages of the outpatients' department at the Combined Military Hospital (CMH) in Lahore, Pakistan, over a period of seven weeks (23rd April to 28th May 2014). The number of doctors/personnel and consultation time were considered as outputs, where consultation time was the non-discretionary output. The two inputs were wait time and length of queue. Additionally, VBA programming in Excel has been utilized to develop the dynamic framework for continuous queue monitoring. FINDINGS: The inadequate availability of personnel was observed as the critical issue for long wait times, along with overcrowding and variable arrival pattern of walk-in patients. The DEA model displayed the "required" number of personnel, corresponding to different wait times, indicating queue build-up. ORIGINALITY/VALUE: The current study develops a queue evaluation model for a busy outpatients' department in a public hospital, where "all" patients are walk-in and no appointment systems. This model provides vital information in the form of "required" number of personnel which allows the administrators to control the queue pre-emptively minimizing wait times, with optimal yet dynamic staff allocation. Additionally, the dynamic framework specifically targets practical implementation in resource-poor public hospitals of emerging economies for continuous queue monitoring.

3.
Int Rev Neurobiol ; 146: 1-44, 2019.
Article in English | MEDLINE | ID: mdl-31349924

ABSTRACT

5-Hydroxytryptophan (5-HTP), a precursor of serotonin, is therapeutically used for several psychiatric disorders such as anxiety and depression in the clinic. However, severe side effects, including abnormal mental functions, behavioral disturbances and intolerance are associated with this treatment. 5-HTP-induced elevation of plasma and brain serotonin levels may affect blood-brain barrier (BBB) breakdown, edema formation and regional cerebral blood flow (CBF) disturbances. Breakdown of BBB to serum proteins leads to vasogenic brain edema formation and cellular injuries. However, 5-HTP-neurotoxicity is still not well known. In this investigations 5-HTP induced elevation of endogenous plasma and brain serotonin levels and its effect on BBB breakdown, edema formation neuronal injuries was examined in a rat model. Furthermore, potential role of oxidative stress and nitric oxide (NO) was evaluated. In addition, several neurochemical agents such as p-CPA (5-HT synthesis inhibitor) indomethacin (prostaglandin synthase inhibitor), diazepam (ant stress drug), cyproheptadine, ketanserin (5-HT2 receptor antagonists) and vinblastine (inhibitor of microtubule function) were examined on 5-HT neurotoxicity. Our observations suggest that 4h after 5-HTP administrations, the endogenous serotonin levels increased by fourfold (150mg/kg) in the plasma and brain associated with profound hyperthermia (+3.86±0.24°C, oxidative stress and NO upregulation. Breakdown of the BBB to Evans blue albumin (EBA) in 8 brain regions and to [131]Iodine in 14 brain regions was observed. The CBF exhibited marked reduction in all the brain regions examined. Brain edema and cellular injuries are present in the areas associated with BBB disruption. Drug treatments reduced the BBB breakdown, edema formation NO production and brain pathology. These observations are the first to point out that 5-HTP-neurotoxicity caused by BBB breakdown, edema formation and NO production is instrumental in causing adverse mental and behavioral abnormalities, not reported earlier.


Subject(s)
5-Hydroxytryptophan/adverse effects , Blood-Brain Barrier/drug effects , Brain Edema/pathology , Cerebrovascular Circulation/drug effects , 5-Hydroxytryptophan/antagonists & inhibitors , Albumins/metabolism , Animals , Behavior, Animal/drug effects , Brain/metabolism , Brain/pathology , Brain Edema/chemically induced , Cyproheptadine/pharmacology , Diazepam/pharmacology , Fenclonine/pharmacology , Indomethacin/pharmacology , Ketanserin/pharmacology , Male , Nitric Oxide Synthase Type I/metabolism , Rats , Serotonin/blood , Serotonin/metabolism , Vinblastine/pharmacology
4.
Int Rev Neurobiol ; 146: 45-81, 2019.
Article in English | MEDLINE | ID: mdl-31349932

ABSTRACT

Several lines of evidences show that anesthetics influence neurotoxicity and neuroprotection. The possibility that different anesthetic agents potentially influence the pathophysiological and functional outcome following neurotrauma was examined in a rat model of concussive head injury (CHI). The CHI was produced by an impact of 0.224N on the right parietal bone by dropping a weight of 114.6g from a 20cm height under different anesthetic agents, e.g., inhaled ether anesthesia or intraperitoneally administered ketamine, pentobarbital, equithesin or urethane anesthesia. Five hour CHI resulted in profound volume swelling and brain edema formation in both hemispheres showing disruption of the blood-brain barrier (BBB) to Evans blue and radioiodine. A marked decrease in the cortical CBF and a profound increase in plasma or brain serotonin levels were seen at this time. Neuronal damages were present in several parts of the brain. These pathological changes were most marked in CHI under ether anesthesia followed by ketamine (35mg/kg, i.p.), pentobarbital (50mg/kg, i.p.), equithesin (3mL/kg, i.p.) and urethane (1g/kg, i.p.). The functional outcome on Rota Rod performances or grid walking tests was also most adversely affected after CHI under ether anesthesia followed by pentobarbital, equithesin and ketamine. Interestingly, the plasma and brain serotonin levels strongly correlated with the development of brain edema in head injured animals in relation to different anesthetic agents used. These observations suggest that anesthetic agents are detrimental to functional and pathological outcomes in CHI probably through influencing the circulating plasma and brain serotonin levels, not reported earlier. Whether anesthetics could also affect the efficacy of different neuroprotective agents in CNS injuries is a new subject that is currently being examined in our laboratory.


Subject(s)
Anesthetics/adverse effects , Blood-Brain Barrier/metabolism , Brain Edema/physiopathology , Brain/metabolism , Brain/pathology , Craniocerebral Trauma/physiopathology , Serotonin/metabolism , Animals , Brain/drug effects , Cerebrovascular Circulation , Craniocerebral Trauma/metabolism , Evans Blue/metabolism , Iodine Radioisotopes/metabolism , Male , Motor Skills/drug effects , Rats , Rotarod Performance Test , Serotonin/blood
5.
Int J Health Care Qual Assur ; 29(2): 123-40, 2016.
Article in English | MEDLINE | ID: mdl-26959894

ABSTRACT

PURPOSE: The purpose of this paper is to develop an integrated patient-focused analytical framework to improve quality of care in accident and emergency (A & E) unit of a Maltese hospital. DESIGN/METHODOLOGY/APPROACH: The study adopts a case study approach. First, a thorough literature review has been undertaken to study the various methods of healthcare quality management. Second, a healthcare quality management framework is developed using combined quality function deployment (QFD) and logical framework approach (LFA). Third, the proposed framework is applied to a Maltese hospital to demonstrate its effectiveness. The proposed framework has six steps, commencing with identifying patients' requirements and concluding with implementing improvement projects. All the steps have been undertaken with the involvement of the concerned stakeholders in the A & E unit of the hospital. FINDINGS: The major and related problems being faced by the hospital under study were overcrowding at A & E and shortage of beds, respectively. The combined framework ensures better A & E services and patient flow. QFD identifies and analyses the issues and challenges of A & E and LFA helps develop project plans for healthcare quality improvement. The important outcomes of implementing the proposed quality improvement programme are fewer hospital admissions, faster patient flow, expert triage and shorter waiting times at the A & E unit. Increased emergency consultant cover and faster first significant medical encounter were required to start addressing the problems effectively. Overall, the combined QFD and LFA method is effective to address quality of care in A & E unit. PRACTICAL/IMPLICATIONS: The proposed framework can be easily integrated within any healthcare unit, as well as within entire healthcare systems, due to its flexible and user-friendly approach. It could be part of Six Sigma and other quality initiatives. ORIGINALITY/VALUE: Although QFD has been extensively deployed in healthcare setup to improve quality of care, very little has been researched on combining QFD and LFA in order to identify issues, prioritise them, derive improvement measures and implement improvement projects. Additionally, there is no research on QFD application in A & E. This paper bridges these gaps. Moreover, very little has been written on the Maltese health care system. Therefore, this study contributes demonstration of quality of emergency care in Malta.


Subject(s)
Delivery of Health Care, Integrated/organization & administration , Emergency Medical Services/organization & administration , Emergency Service, Hospital/organization & administration , Outcome Assessment, Health Care , Quality Improvement , Developing Countries , Female , Health Services Needs and Demand , Humans , Male , Malta , Organizational Innovation , Program Development , Program Evaluation , Risk Assessment
7.
Int J Health Care Qual Assur ; 23(3): 287-300, 2010.
Article in English | MEDLINE | ID: mdl-20535901

ABSTRACT

PURPOSE: The purpose of this paper is to develop a comprehensive framework for improving intensive care unit performance. DESIGN/METHODOLOGY/APPROACH: The study introduces a quality management framework by combining cause and effect diagram and logical framework. An intensive care unit was identified for the study on the basis of its performance. The reasons for not achieving the desired performance were identified using a cause and effect diagram with the stakeholder involvement. A logical framework was developed using information from the cause and effect diagram and a detailed project plan was developed. The improvement projects were implemented and evaluated. FINDINGS: Stakeholders identified various intensive care unit issues. Managerial performance, organizational processes and insufficient staff were considered major issues. A logical framework was developed to plan an improvement project to resolve issues raised by clinicians and patients. Improved infrastructure, state-of-the-art equipment, well maintained facilities, IT-based communication, motivated doctors, nurses and support staff, improved patient care and improved drug availability were considered the main project outputs for improving performance. The proposed framework is currently being used as a continuous quality improvement tool, providing a planning, implementing, monitoring and evaluating framework for the quality improvement measures on a sustainable basis. PRACTICAL IMPLICATIONS: The combined cause and effect diagram and logical framework analysis is a novel and effective approach to improving intensive care performance. Similar approaches could be adopted in any intensive care unit. ORIGINALITY/VALUE: The paper focuses on a uniform model that can be applied to most intensive care units.


Subject(s)
Intensive Care Units/organization & administration , Quality Assurance, Health Care/organization & administration , Communication , Health Personnel/organization & administration , Humans , Information Systems/organization & administration , Models, Organizational , Organizational Culture
8.
J Environ Manage ; 88(4): 1384-95, 2008 Sep.
Article in English | MEDLINE | ID: mdl-17854976

ABSTRACT

Site selection is a key activity for quarry expansion to support cement production, and is governed by factors such as resource availability, logistics, costs, and socio-economic-environmental factors. Adequate consideration of all the factors facilitates both industrial productivity and sustainable economic growth. This study illustrates the site selection process that was undertaken for the expansion of limestone quarry operations to support cement production in Barbados. First, alternate sites with adequate resources to support a 25-year development horizon were identified. Second, technical and socio-economic-environmental factors were then identified. Third, a database was developed for each site with respect to each factor. Fourth, a hierarchical model in analytic hierarchy process (AHP) framework was then developed. Fifth, the relative ranking of the alternate sites was then derived through pair wise comparison in all the levels and through subsequent synthesizing of the results across the hierarchy through computer software (Expert Choice). The study reveals that an integrated framework using the AHP can help select a site for the quarry expansion project in Barbados.


Subject(s)
Calcium Carbonate , Barbados , Construction Materials , Database Management Systems , Decision Support Techniques
9.
Article in English | MedCarib | ID: med-17546

ABSTRACT

The development of an information system in Caribbean public sector organisations is usually seen as a matter of installing hardware and software according to a directive from senior management, without much planning. This causes huge investment in procuring hardware and software without improving overall system performance. Increasingly, Caribbean organisations are looking for assurances on information system performance before making investment decisions not only to satisfy the funding agencies, but also to be competitive in this dynamic and global business world. This study demonstrates an information system planning approach using a process-reengineering framework. Firstly, the stakeholders for the business functions are identified along with their relationships and requirements. Secondly, process reengineering is carried out to develop the system requirements. Accordingly, information technology is selected through detailed system requirement analysis. Thirdly, cost-benefit analysis, identification of critical success factors and risk analysis are carried out to strengthen the selection. The entire methodology has been demonstrated through an information system project in the Barbados drug service, a public sector organisation in the Caribbean.


Subject(s)
Humans , Information Systems/organization & administration , Information Systems/standards , Case Reports
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