505 research outputs found
Patient involvement in selection of immunosuppressive regimen following transplantation.
Transplantation has made a considerable difference to the lives of many patients. However, feedback from patients indicates that although having a transplant is a hugely positive experience, having to take medications indefinitely is one of the biggest challenges. An ideal scenario would be no medications following a transplant. A compromise would be a minimal number of medications, with minimal restrictions and as simple a regimen as possible. Although there is considerable research going into fine-tuning the management of the immune response to a transplant, to date there is no universal regimen that enables patients to remain free of immunosuppressant medications, making adherence paramount to maintain long-term allograft survival. This paper reviews the available immunosuppressant regimens and factors influencing choice from both the clinician's and the patient's perspective. Factors influencing the decision-making process, such as quality of life for patients, their satisfaction, acceptability, and adherence uptake are reviewed. We conclude with a further assessment of patient choice as a factor in regimen selection, its impact on adherence, and its implications
Modelling Internet Traffic Streams with Ga/M/1/K Queuing Systems under Self-similarity
High-intensity concurrent arrivals of request packets in Internet traffic can cause dependence of event-to-event-times of the requests being served, which causes non-memoryless, modelled with heavy-tail distributions unlike common known traffics. The performance of Internet traffic can be examined using analytical models for the purpose of optimizing the system to reduce its operating costs. Therefore, our study examined a Ga/M/1/K Internet queue class (Gamma arrival processes, Ga; with memoryless-Poisson service process, M; a single server, 1, and K waiting room) and proposed specific derivations of its performance indicators. Real-life data of a corporate organisation Internet server was monitored at both peak and off-peak periods of its usage for Internet traffic data analysis. The minimum ‘0’ in the arrival process indicates self-similarity and was assessed using Hurst parameter, H, and their (standard deviation). ‘H’ > 0.5 arrival process in the peak period only, indicates self-similarity. Performance of Ga/M/1/K was compared with various queuing Internet traffic models used in existing literatures. Results showed that the value of the waiting room size for Ga/M/1/K has closest ties with true self-similar model at peak-periods usage of the Internet, which indicates possible concurrent arrival of clients' requests leading to more usage of the waiting room, but with light-tailed queue model at the off-peak periods. Therefore, the proposed Ga/M/1/K model can assist in evaluating the performance of high-intensity self-similar Internet traffic.
Keywords: Internet traffic; self-similarity; Ga/M/1/K model; gamma distributio
Pandemic pandemonium and primary care networks: Experiences of establishing primary care placements in a new medical school
Background: In 2018 five new medical schools were announced to support the expansion of the workforce. The Kent and Medway programme features early clinical placements in the community. These start in year one, structured as immersion weeks in Primary Care Networks. The KMMS school opened in September 2020 in the midst of the COVID-19 pandemic with all of its attendant challenges. We report on the challenges of selecting and establishing the placements in the newly established primary care networks (PCN). These offer a unique opportunity for medical students to learn about the provision of proactive personalised and co-ordinated multidisciplinary care at an early and formative stage in their careers. Over the course of the first year, multiple adjustments to the learning format were required including a move to blended learning.
Summary of Work Initial: challenges included agreeing selection criteria for the PCNs before attending to the legal complexities of contracting and negotiating a service level agreement with the networks, addressing the needs of all stakeholders. Faculty development was conducted remotely. Challenges of the immersion weeks included compromises associated with lockdown restrictions, limited movement across organisations, social distancing and “shielding” students. Over the course of the immersion weeks, we moved to a blended format, navigating the challenges of recorded assessment presentations.
Summary of Results: We will present a logic model evaluation of this first year of placements. This summarises the resources required, activities (aspects of implementation) as well as the outcomes. These are considered from the perspective of the school, the GP faculty and students.
Discussion and Conclusions: Innovation in establishing a new medical school brings a unique set of challenges to negotiate. PCNs are contractual collaborations between practices (not legal entities), presenting a challenge for both contracting and quality evaluation. COVID-19 constraints compounded the complexities but offered a unique opportunity to observe multidisciplinary, cross organisation work at first hand in the delivery of the COVD vaccination programme. This balanced the change to a blended learning format.
Take Home Messages: Flexibility is a key factor in the successful implementation of a new medical school programme involving a range of stakeholders, particularly during a pandemic
Chromosomal studies of the African dotted catfish Parauchenoglanis monkei (Keilhack 1910)
The chromosomal data within the genus Parauchenoglanis is scarce. The two main species of the genus identified in Nigeria are P. buttikoferi and P. monkei. The chromosome of P. monkei was assessed in this study to provide information on the diploid number and karyotype. Samples (n=40) were collected in Opa River, Ile-Ife, Osun State, Nigeria. The chromosomes of the specimen were extracted using the Giemsa staining technique. The mitotic chromosome spread has a diploid chromosome number of 2n=50. The autosomal fundamental number was 55, while the karyotype formula was 2n=2M+ 8m+40T. The diploid chromosome number of 50 obtained for P. monkei is within the range for catfishes
Malignant and noninvasive skin tumours in renal transplant recipients.
Background. Transplant recipients require immunosuppression to prevent graft rejection. This conveys an increased risk of malignancy, particularly skin tumours. There is a need for up-to-date data for the South of England. Method. Pathology records were reviewed for 709 kidney transplant recipients on immunosuppression at our hospital from 1995 to 2008. Skin tumours were recorded/analysed. Results. Mean age at transplant was 46 years. Mean length of follow-up was 7.2 years and total follow-up was 4926 person-years. 53 (7.5%) patients (39/458 (8.5%) males and 14/251 (5.6%) females) developed ≥1 skin malignancy. Cumulative incidences of 4.0%, 7.5%, and 12.2% were observed for those with <5, <10, and ≥10 years follow-up, respectively. The rate was 45 tumours per 1000 person-years at risk. Additionally, 21 patients (3.0%) only had noninvasive tumours. 221 malignant skin tumours were found: 50.2% were SCCs, 47.1% BCCs, and 2.7% malignant melanomas. Mean years to first tumour were 5.8. Mean number of tumours per patient was 4, with mean interval of 12 months. Conclusions. Despite changes in transplantation practice during the time since the last data were published in this region, these findings are similar to previous studies. This adds to the evidence allowing clinicians to inform patients in this region of their risk
Analytical determination of load resistance value for MQ-series gas sensors: MQ-6 as case study
The MQ-series gas sensors are attractive candidates in the area of gas concentration sensing due to their high sensitivity and low cost. Even though the sensor circuit sensitivity and sensor power dissipation level both depend on load resistance, the process of the load resistance selection has not been well researched, hence the need for this study. The derivation of model equations for determining the sensor circuit sensitivity and sensor power dissipation is presented. The derived equations were used to investigate a typical scenario of MQ-6 gas sensor under the influence of liquified petroleum gas (LPG). The variation of sensitivity with load resistance and that of power dissipation with sensor resistance were parametrically investigated. The load resistance that yields maximum sensor circuit sensitivity with the maximum sensor power dissipation less than the set threshold is the candidate resistance for the sensor circuit. The 20 kΩ load resistance recommended for MQ-6 in the datasheet was authenticated in this study, yielding the maximum possible sensor circuit sensitivity and tolerable sensor power dissipation of 0.195 mV/ppm and 3.125×10−4 W, respectively
Effects of Na2Cr2O7 Inhibitor on the Corrosion Potential Response of Steel Reinforced Concrete in Saline Medium
Electrochemical monitoring method of the open circuit potential was used to investigate the effect of
the concentrations of Na2Cr2O7 on the corrosion potential response of steel reinforced concrete in
sodium chloride medium. In the study, five different concentrations of Na2Cr2O7 admixtures were
employed in a system of replicated samples of steel-reinforced concrete specimens partially
immersed in 3.5% NaCl to simulate marine and saline environments. Forty days measured responses
from these were subjected to the statistical analyses of the Normal and the Weibull distribution
functions and tested using the Kolmogorov-Smirnov goodness of fit criteria. Results obtained from the
analyses identified 4 g Na2Cr2O7 with optimal averaged potential response inhibition performance by
the Normal model which showed better agreements in its models of Na2Cr2O7 potential test data than
that obtained from the Weibull model of the same data. These bear pertinent implications on the need
for suitability studies of appropriate statistical distribution for studying performance of corrosion
inhibitors even as suggestions were proffered for addressing results conflicts among replicates of
steel reinforced concrete samples employed
Hosting the 16th AHILA Conference in Ibadan, Nigeria: organization, achievements, challenges and lessons learnt
Attending a scientific conference offers researchers several potential benefits including opportunity to present and receive constructive feedback from professional colleagues. Organizing such conference is also beneficial to the hosts who can acquire skills for coordination, communication and networking. However, the process is fraught with many challenges. One hundred and nine professionals attended the 16th AHILA conference from 22 countries in Africa, Europe and United States of America. The conference agenda was balanced, integrating skills acquisition, information for career development, sources of evidence-based free e-resources, including databases, and e-books for libraries covering health-related topics. This article describes achievement, challenges and lessons learnt in hosting the conference and could serve as a guide for health information professionals planning a similar conference in the future
PID controller for microsatellite yaw-axis attitude control system using ITAE method
The need for effective design of satellite attitude control (SAC) subsystem for a microsatellite is imperative in order to guarantee both the quality and reliability of the data acquisition. A proportional-integral-derivative (PID) controller was proposed in this study because of its numerous advantages. The performance of PID controller can be greatly improved by adopting an integral time absolute error (ITAE) robust controller design approach. Since the system to be controlled is of the 4th order, it was approximated by its 2nd order version and then used for the controller design. Both the reduced and higher-order pre-filter transfer functions were designed and tested, in order to improve the system performance. As revealed by the results, three out of the four designed systems satisfy the design specifications; and the PD-controlled system without pre-filter transfer function was recommended out of the three systems due to its structural simplicity, which eventually enhances its digital implementation
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