Left ventricular angiograms of 60 patients with ischaemic heart disease and 10 normal subjects were digitized frame by frame in order to study abnormalities of wall movement during the period of isovolumic relaxation. Plots were made of regional wall movement around the cavity throughout the cardiac cycle. In normal subjects 1*5 to 3-0 mm of symmetrical outward wall movement occurred during isovolumic relaxation, associated with an apparent increase of left ventricular volume of 10±4 per cent. The corresponding peak velocities of wall movement were 4-3 to 5 7 cm/s, significantly less than those recorded in the same region of the cavity after mitral valve opening. In patients with ischaemic heart disease, the following abnormalities were encountered:(1) Abnormal inward movement, which, in single coronary artery disease, occurred in the area supplied by the affected vessel.(2) Abnormal outward movement of more than 6 mm in non-affected areas which appeared to be a compensatory phenomenon.(3) An abnormal cavity shape change towards a more circular configuration before mitral valve opening.(4) Reduced peak rates of wall movement in affected areas during systole and filling. It is concluded that such inward wall movement during isovolumic relaxation is abnormal and a sign of local ischaemia whose presence has significant effects on overall left ventricular function in both systole and diastole.

The advent of cloud computing has provided people around the world with unprecedented access to computational power and enabled rapid growth in technologies such as machine learning, the computational demands of which incur a high energy cost and a commensurate carbon footprint. As a result, recent scholarship has called for better estimates of the greenhouse gas impact of AI: data scientists today do not have easy or reliable access to measurements of this information, which precludes development of actionable tactics. We argue that cloud providers presenting information about software carbon intensity to users is a fundamental stepping stone towards minimizing emissions.In this paper, we provide a framework for measuring software carbon intensity, and propose to measure operational carbon emissions by using location-based and time-specific marginal emissions data per energy unit. We provide measurements of operational software carbon intensity for a set of modern models covering natural language processing and computer vision applications, and a wide range of model sizes, including pretraining of a 6.1 billion parameter language model. We then evaluate a suite of approaches for reducing emissions on the Microsoft Azure cloud compute platform: using cloud instances in different geographic regions, using cloud instances at different times of day, and dynamically pausing cloud instances when the marginal carbon intensity is above a certain threshold. We confirm previous results that the geographic region of the data center plays a significant role in the carbon intensity for a given cloud instance, and find that choosing an appropriate region can have the largest operational emissions reduction impact. We also present new results showing that the time of day has meaningful impact on operational software carbon intensity.Finally, we conclude with recommendations for how machine learning practitioners can use software carbon intensity information to reduce environmental impact.

In order to study the relation between the 'rapid filling wave' of the apex cardiogram and left ventricular filling, simultaneous apex cardiograms, phonocardiograms, and echocardiograms were recorded in 57 patients. Continuous measurements of left ventricular dimension were derived from the echocardiograms by digitization using manual tracing and a computer. Possible errors in the use of a single dimension to assess left ventricular filling were investigated by frame-by-frame analysis of cineangiocardiograms in 37 patients, and the timing of changes in transverse diameter found to correlate closely with those in cavity area. Mitral valve opening, shown as the initial separation of the valve cusps by echocardiography, preceded the 'O' point of the apex cardiogram in all except 3 patients, the 'O' point appearing to correlate more closely with the time of peak rate of outward wall movement. A third heart sound was present in 29 patients, and in 25 of these it occurred later than the peak rate of wall movement (ment interval 51 ms). The end of rapid filling derived from the dimension trace occurred in relation to the third heart sound after a mean interval of 9 ms, with a range from 50 ms before to 80 ms after the third sound. Peak rates of wall movement were similar in patients with and without third heart sounds. The results show that outward left ventricular wall movement begins with a period of acceleration, with peak rates occurring synchronous with the 'O' point of the apex cardiogram and thus with the nadir of the ventricular pressure trace. Outward wall movement becomes less rapid thereafter, so that the rapid filling wave of the apex cardiogram does not reflect the time of rapid filling of the left ventricle. The 'O' point is not related to mitral valve movement nor does the third heart sound bear a consitent relation to any aspect of left ventricular wall movement.

No abstract

SUMMARYThe relationship between external records of precordial movement XLI, February 1970 Ejection fraction movement records is limited. Agress and Fields4 showed that the first derivative of the left ventricular pressure pulse (dp/dt) bears some resemblance to the external apical records obtained by different technics. The similarity between dp/dt and the first derivative of apical displacement (dF/dt)

Fifty-six patients with aortic insufficiency, presumably syphilitic in origin, were encountered among 345 patients with a history of syphilis in a municipal clinic and hospital population. Little physical handicap and relative longevity characterized the involved patients. Of the syphilitic patients, 33% (9 of 27) of those over 70 years of age had aortic insufficiency, while only 7% (5 of 70) of those under 70 years of age were so involved. The venereal disease research laboratory test for syphilis was nonreactive in 30%

No abstract

No abstract