Non-Newtonian and flow pulsatility effects in simulation models of a stented intracranial aneurysm

Permission to redistribute provided by publishers.Three models of different stent designs implanted in a cerebral aneurysm, originating from the Virtual Intracranial Stenting Challenge'07, are meshed and the flow characteristics simulated using commercial computational fluid dynamics (CFD) software in order to investigate the effects of non-Newtonian viscosity and pulsatile flow. Conventional mass inflow and wall shear stress (WSS) output are used as a means of comparing the cfd simulations. In addition, a WSS distribution is presented, which clearly discriminates in favour of the stent design identified by other groups. It is concluded that non-Newtonian and pulsatile effects are important to include in order to avoid underestimating wss, to understand dynamic flow effects, and to discriminate more effectively between stent designs. © Authors 2011

Analysis of maternal and newborn training curricula and approaches to inform future trainings for routine care, basic and comprehensive emergency obstetric and newborn care in the low- and middle-income countries: Lessons from Ethiopia and Nepal

Program managers routinely design and implement specialised maternal and newborn health trainings for health workers in low- and middle-income countries to provide better-coordinated care across the continuum of care. However, in these countries details on the availability of different training packages, skills covered in those training packages and the gaps in their implementation are patchy. This paper presents an assessment of maternal and newborn health training packages to describe differences in training contents and implementation approaches used for a range of training packages in Ethiopia and Nepal. We conducted a mixed-methods study. The quantitative assessment was conducted using a comprehensive assessment questionnaire based on validated WHO guidelines and developed jointly with global maternal and newborn health experts. The qualitative assessment was conducted through key informant interviews with national stakeholders involved in implementing these training packages and working with the Ministries of Health in both countries. Our quantitative analysis revealed several key gaps in the technical content of maternal and newborn health training packages in both countries. Our qualitative results from key informant interviews provided additional insights by highlighting several issues with trainings related to quality, skill retention, logistics, and management. Taken together, our findings suggest four key areas of improvement: first, training materials should be updated based on the content gaps identified and should be aligned with each other. Second, trainings should address actual health worker performance gaps using a variety of innovative approaches such as blended and self-directed learning. Third, post-training supervision and ongoing mentoring need to be strengthened. Lastly, functional training information systems are required to support planning efforts in both countries

Primary care and pattern of skin diseases in a mediterranean island

BACKGROUND: In Greece where primary health care services are not fully developed, patients with simple or minor conditions have to attend to hospitals to be treated. We analysed the data of patients with cutaneous disorders attending the tertiary referral hospital on the Island of Crete, with the aim to identify the most common conditions that patients complain of, in order to define the areas where the education of General Practitioners in Dermatology must focus. METHODS: All patients attending the Dermatology ambulatory office in the Emergency Department of the University General Hospital of Heraklion from January 2003 to December 2003 were included in this retrospective analysis. The medical records of the patients (history, physical examination and laboratory investigations) were analysed to ascertain the diagnosis and the management of cases. All patients were evaluated by qualified dermatologists. RESULTS: A total of 3715 patients attended the Dermatology Clinic. Most patients were young adults in the age group 21–40 years (38.4%), and the male to female ratio was 1 to 1.2. Allergic skin diseases, mostly dermatitis and urticaria (35.7%) were the most common for attendance, followed by infectious diseases (26.1%) and insect bites (10.2%). Inflammatory and autoimmune disorders accounted for 7.9% of the cases. Pruritus of unknown origin was diagnosed in 6.3% of patients. Skin tumors were detected in 2.7%. The management of the vast majority of cases (85.0%) consisted of advice with or without a prescription, while only 4.8% of patients required admission. CONCLUSION: Allergic and infectious skin diseases were the most common cutaneous diseases in patients attending this tertiary University hospital, while the management of most patients did not require specialised care. On the basis of the present data, the training of primary health care providers in Dermatology should emphasize these common conditions, with the aim of improving primary care and alleviating the burden on hospital care

Vortex formation and recirculation zones in left anterior descending artery stenoses: computational fluid dynamics analysis

Flow patterns may affect the potential of thrombus formation following plaque rupture. Computational fluid dynamics (CFD) were employed to assess hemodynamic conditions, and particularly flow recirculation and vortex formation in reconstructed arterial models associated with ST-elevation myocardial infraction (STEMI) or stable coronary stenosis (SCS) in the left anterior descending coronary artery (LAD). Results indicate that in the arterial models associated with STEMI, a 50% diameter stenosis immediately before or after a bifurcation creates a recirculation zone and vortex formation at the orifice of the bifurcation branch, for most of the cardiac cycle, thus allowing the creation of stagnating flow. These flow patterns are not seen in the SCS model with an identical stenosis. Post-stenotic recirculation in the presence of a 90% stenosis was evident at both the STEMI and SCS models. The presence of 90% diameter stenosis resulted in flow reduction in the LAD of 51.5% and 35.9% in the STEMI models and 37.6% in the SCS model, for a 10 mmHg pressure drop. CFD simulations in a reconstructed model of stenotic LAD segments indicate that specific anatomic characteristics create zones of vortices and flow recirculation that promote thrombus formation and potentially myocardial infarction

Evaluation of durum wheat varieties for yield and yield related traits in highland areas of southern Ethiopia

Durum wheat productivity in Ethiopia is hindered by different factors mainly lack of improved adapted varieties for specific locations. This experiment was done to identify the most performing durum wheat varieties in the tested environment. The average productivity of the tested genotypes were evaluated at two locations (Alicho and Analimo) using randomized complete block design with four replication for two consecutive years (2016 and 2017). The experimental material consists of seven improved durum wheat genotypes. The Combined analysis of variance showed significant (P<0.05) difference among tested genotypes on collected parameter indicating the presence of adequate variability. The highest average grain yield recorded was 4446 kg ha-1 from Hitosa variety while the lowest obtained was 3634 kg ha-1 from Denbi variety. Grain yield had strong positive correlations (P<0.01) with plant height, number of seed spike-1 and biomass

Prevalence and Characteristics of Polypharmacy and Drug-Drug Interaction in Afincho Ber Health Centre, Addis Ababa, Ethiopia

Polypharmacy is the prescription of multiple medications for a patient which is a common problem worldwide. The aim of this study was to identify the extent of polypharmacy and occurrence of drug–drug interaction in Afincho Ber Health Centre, Addis Ababa. The study was conducted by retrospective crosssectional review of prescriptions of all adult outpatients for a period of 6 months at Afincho Ber Health Centre. In this study, polypharmacy was defined as prescription of 4 or more drugs. All the statistical calculations were performed using SPSS® software version 20. Drug-drug interactions were identified using computer based Micromedex2® software. Among the total of 271 prescriptions analyzed, 113 (41.70%) were identified as polypharmacy. At least one drug-drug interaction was detected in 106 (39.1%) prescriptions of which 17 (16.04%) were severe drug interactions. In conclusion, polypharmacy and drug-drug interaction were both identified to be commonly encountered problems among the outpatients.Keywords: Polypharmacy, Drug-drug Interactions, Health Centre, Retrospective Cross-sectional Review, Ethiopi

Towards the Development of a Photovoltaic Array Fault Detection and Diagnosis (PVAFDD) System

The perpetual increment in energy demand continues to put pressure on the South African Economy. Independent Power Producers (IPPs) have been contracted to relieve the strain by supplementing energy production using solar photovoltaic (PV) technologies. These IPPs are paid per megawatt they produce and face stiff penalties should they fail to deliver on contractual obligations. Naturally solar PV plants are susceptible to numerous PV faults that could lead to a negative return on investment. It therefore makes economic sense to adopt mechanisms that can be able to detect, localize and diagnose PV faults when they occur within a solar PV system. There exists an extensive literature on how to detect and diagnose PV faults, however, localizing PV faults is still in its infancy. This paper proposes to cater to the needs of the IPPs by developing an intelligent PV Array Fault Detection and Diagnostics (PVAFDD) system capable of localizing PV faults which can be embedded into the Supervisory Control and Data Acquisition (SCADA) system used to manage and control such PV systems. The PVAFDD system is based on a machine learning (ML) model implemented using logistic regression algorithm. The ML model is trained using meteorological data ranging over a period of eight years in Alice, Eastern Cape. Using simulations driven by real-life data scenarios, we have been able to train, validate and test the PVAFDD system. When the PVAFDD system detects a fault, a cascade of real-time PVA tests is undertaken to localize the PV fault. The system then carries out PVA fault diagnostics and gives recommendations on the PV fault classification. Corrective measures can therefore be implemented on the affected PVA swiftly reducing the downtime of the PV plant, ergo proving to be a cost-effective measure that offers a competitive edge to IPPs using the PVAFDD system

Novel filaggrin mutation but no other loss-of-function variants found in Ethiopian patients with atopic dermatitis

Atopic dermatitis (AD) is a common, complex inflammatory skin disorder where a defect skin barrier is central in the pathogenesis. Mutations in the filaggrin gene cause ichthyosis vulgaris (IV). IV is one of several keratinization disorders named ichthyoses where mutations in skin barrier genes are a common underlying genetic factor. Furthermore, filaggrin mutations are a major risk factor for moderate to severe AD. The aim of the work reported in this thesis is to improve the understanding of the genetic mechanisms of skin barrier defects associated with AD, and to identify whether AD and other common disorders of keratinisation may share genetic susceptibility factors related to skin barrier dysfunction. Paper I presents data suggesting that filaggrin mutations may be rare in Ethiopian AD and IV patients, implying other mechanisms should be more important in the pathogenesis of IV and AD in this ethnic group. Paper II presents a novel mutation in the steroid sulfatase gene in a patient with clinical signs of common ichthyosis type. In paper III association between filaggrin mutations and childhood onset of psoriasis was tested. No association to any prevalent filaggrin mutations was found, and no novel mutations. This indicates that filaggrin loss-of- function variants do not have a strong effect on the onset of psoriasis in childhood. In paper IV it is demonstrated that functional parameters and gene expression in molecular pathways in vivo is altered in patients suffering from AD and IV and depend on filaggrin genotype. Patients with filaggrin mutations displayed a severe phenotype with impaired barrier function measured as increased trans-epidermal water loss, and significantly altered pH levels. Furthermore, the numbers of genes with altered expression were significantly higher in patients with low or absent filaggrin expression. These pathways include many genes involved in inflammation, epidermal differentiation, lipid metabolism, cell signalling and adhesion. Paper V represents a candidate gene study where expression analysis links the epidermal transglutaminases 1 and 3 to the manifestation of AD and genetic analysis suggests that genetic variation at the transglutaminase 1 locus could be involved in the development of the disease. The results of the work reported in this thesis provides additional descriptive information and further elucidates the pathogenesis underlying AD and other disorders of keratinization, in particular in relation to filaggrin deficiency. Better understanding of the genetic factors and molecular and functional consequences should hopefully enable future individually designed barrier restoring therapy