Indirect Measurement of Left Ventricular EndDiastolic Pressure in Congestive Cardiomyopathy and Constrictive Pericarditis

Pulmonary artery diastolic and pulmonary capillary wedge mean pressures were measured in 30 patients with congestive cardiomyopathy and in 30 patients with constrictive pericarditis. These measurements were compared with left ventricular end-diastolic pressure (LVEDP) to assess their value as indirect measurements of left ventricular function. There was close correlation between the indirect measurements and LVEDP in both disorders: a better statistical correlation was achieved using a power curve than with linear regression, since pulmonary artery diastolic pressure increased disproportionately when LVEDP was high.S. Afr. Med. J., 48, 540 (1974

The use of happiness research for public policy

Research on happiness tends to follow a "benevolent dictator" approach where politicians pursue people's happiness. This paper takes an antithetic approach based on the insights of public choice theory. First, we inquire how the results of happiness research may be used to improve the choice of institutions. Second, we show that the policy approach matters for the choice of research questions and the kind of knowledge happiness research aims to provide. Third, we emphasize that there is no shortcut to an optimal policy maximizing some happiness indicator or social welfare function since governments have an incentive to manipulate this indicator

Generalised left ventricular dysfunction after traumatic right coronary artery - right atrial fistula

A patient with traumatic right coronary artery to right atrial fistula, which was repaired by direct closure and aortocoronary saphenous vein bypass grafting, is described. Cardiac catheterisation and selective cine angiocardiography were performed pre- and postoperatively, and left ventricular (LV) function was studied in detail by invasive and non-invasive techniques. There was regional (diaphragmatic) LV asynergy but also generalised impairment of myocardial function, and these abnormalities persisted after operation.S. Afr. Med. J., 48, 1829 (1974)

Towards a Standard Approach for Wear Testing of Wheel and Rail Materials

Examination of the literature for wear testing methodologies for wheel and rail material reveals that while only a few different techniques have been used there is a wide variety in exactly how the tests have been conducted and the resulting data reported. This makes comparison of the data very difficult. This work, carried out as part of the International Collaborative Research Initiative (ICRI) which is aiming to bring together wheel/rail interface researchers from across the world to collate data and knowledge to try to solve some of the common problems that are faced, has examined the different approaches used and attempted to pull together all the good practice used into a test specification for future twin disc testing for wheel and rail materials. Adoption of the method will allow data to be compared reliably and eventually enable data to be compiled into wear maps to use as input, for example, to multi-body dynamics simulation wear prediction tools

Development of the Knowledge of Genome Sequencing (KOGS) questionnaire

OBJECTIVE: Whole-genome sequencing is being implemented in research and clinical care, yet tools to assess patients' knowledge are lacking. Our aim was to develop a robust measure of whole-genome sequencing knowledge suitable for patients and other stakeholders including research participants, public, students, and healthcare professionals. METHODS: An initial set of 17 items was developed via an iterative process including literature review, expert consultation, focus groups, and cognitive interviews with patients, and then administered to 243 individuals. We used exploratory factor analysis and item-response theory to confirm the psychometric suitability of the candidate items for assessing whole-genome sequencing knowledge. RESULTS: There was a strong main component after removing 5 items with low factor loadings. Item and scale homogeneity was achieved using Mokken scale analysis. Three further items were removed because they were misfits, inverse duplicates or resulted in local dependency. The remaining nine items fitted the two-parameter logistic IRT model which achieved excellent fit to the observed data. Cronbach's alpha was 0.79 indicating acceptable reliability. CONCLUSION: The KOGS, developed using a rigorous psychometric approach, is a brief and reliable tool. PRACTICE IMPLICATIONS: The KOGS may prove useful for researchers and healthcare professionals using whole-genome sequencing with patients and other stakeholders

Remarks on the method of comparison equations (generalized WKB method) and the generalized Ermakov-Pinney equation

The connection between the method of comparison equations (generalized WKB method) and the Ermakov-Pinney equation is established. A perturbative scheme of solution of the generalized Ermakov-Pinney equation is developed and is applied to the construction of perturbative series for second-order differential equations with and without turning points.Comment: The collective of the authors is enlarged and the calculations in Sec. 3 are correcte

Hardness characterisation of grey cast iron and its tribological performance in a contact lubricated with soybean oil

The effect of hardness of grey cast iron flat specimen on its wear and friction on the contact were characterised with the presence of vegetable oil as biolubricant. Prior to the tribological test, the as - received grey cast iron flat specimen hardness was characterised. Friction and wear tests were then conducted using a ball - on - flat reciprocating sliding contact. The one - way analysis of variance (ANOVA) was used to determine the significance of friction and wear data with a 95% significance level. The wear scars after the test were then characterised by surface roughness and wear mechanism. The microstructure and elemental analysis we re also reported. The average value of hardness was 210 HV with a large difference between minimum (185 HV) and maximum (250 HV) values. The friction and wear performance of grey cast iron specimens with soybean oil varied with its hardness. The specimens with higher hardness gave lower friction coefficient and greater wear resistance than the lower hardness specimens. The difference in coefficient of friction produced between high hardness specimens (COF = 0.122) and low hardness specimens (COF = 0.140) wa s 17%. In terms of mass loss, the low hardness 2 specimens (mass loss = 50.38 mg) and the high hardness specimens (mass loss = 12.90 mg) produced a difference of 74%. It is shown that, with soybean oil lubricant, the grey cast iron specimen can produce wide range of tribological data especially on mass loss due to its hardness distribution. The influence of soybean oil lubrication in this work is less in improving the wear resistance (about 7%), but greater for friction reduction (about 24%) compared to an un lubricated grey cast iron surface. The hardness of grey cast iron specimen is an important parameter that needs to be specifically measured and controlled on the contact due to wide hardness distribution of grey cast iron may produce variation in tribologi cal data