34 research outputs found

    Intraaortic balloon counterpulsation as a temporary support measure in decompensated critical aortic stenosis

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    Intraaortic balloon counterpulsation was instituted in two adult patients whose condition was rapidly deteriorating because of critical decompensated valvular aortic stenosis. The acute hemodynamic effect of counterpulsation in these patients was compared with the effect of counterpulsation in three control patients with unstable angina and no aortic valve disease. Augmentation of aortic diastolic pressure was similar in both groups; however, in contrast to the patients with unstable angina, the patients with aortic stenosis had no decrease in left ventricular systolic pressure. Counterpulsation resulted in an increase in the transvalvular pressure gradient, which was associated with a slight increase in stroke volume. In both patients with aortic stenosis, the institution of counterpulsation resulted in marked clinical improvement, which facilitated successful valve replacement surgery.The benefit from counterpulsation in critically decompensated aortic stenosis appears to be derived almost entirely from augmentation of the diastolic coronary filling gradient. The improvement that results from counterpulsation suggests that ischemia is the major cause of decompensation

    Simple statistical probabilistic forecasts of the winter NAO

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    The variability of the North Atlantic Oscillation is a key aspect of Northern Hemisphere atmospheric circulation and has a profound impact upon the weather of the surrounding land masses. Recent success with dynamical forecasts predicting the winter NAO at lead times of a few months has the potential to deliver great socio-economic impacts. Here we find that a linear regression model can provide skillful predictions of the winter NAO based on a limited number of statistical predictors. Identified predictors include El-Niño, Arctic sea ice, Atlantic SSTs and tropical rainfall. These statistical models can show significant skill when used to make out-of-sample forecasts and we extend the method to produce probabilistic predictions of the winter NAO. The statistical hindcasts can achieve similar levels of skill to state-of the art dynamical forecast models, although out-of-sample predictions are less skillful, albeit over a small period. Forecasts over a longer out-of-sample period suggest there is true skill in the statistical models, comparable with that of dynamical forecasting models. They can be used both to help evaluate, and to offer insight into sources of predictability and limitations of, dynamical models

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    Garotas de loja, história social e teoria social [Shop Girls, Social History and Social Theory]

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    Shop workers, most of them women, have made up a significant proportion of Britain’s labour force since the 1850s but we still know relatively little about their history. This article argues that there has been a systematic neglect of one of the largest sectors of female employment by historians and investigates why this might be. It suggests that this neglect is connected to framings of work that have overlooked the service sector as a whole as well as to a continuing unease with the consumer society’s transformation of social life. One element of that transformation was the rise of new forms of aesthetic, emotional and sexualised labour. Certain kinds of ‘shop girls’ embodied these in spectacular fashion. As a result, they became enduring icons of mass consumption, simultaneously dismissed as passive cultural dupes or punished as powerful agents of cultural destruction. This article interweaves the social history of everyday shop workers with shifting representations of the ‘shop girl’, from Victorian music hall parodies, through modernist social theory, to the bizarre bombing of the Biba boutique in London by the Angry Brigade on May Day 1971. It concludes that progressive historians have much to gain by reclaiming these workers and the service economy that they helped create

    Acute ischemic coronary artery disease and ischemic stroke: similarities and differences

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    Although acute myocardial infarction (MI) and acute ischemic stroke share similarities, physicians need to recognize important differences in pathophysiology and how these differences affect acute treatment and prevention to provide optimal patient care. Potential causes of acute ischemic stroke are substantially more heterogeneous than for acute MI, and available acute therapies are substantially more limited. In acute ischemic stroke patients, diagnostic evaluation is paramount in determining eligibility for treatment with the only approved therapy, which must be administered within 3 hours after stroke onset. For patients having acute MI, reperfusion therapy by percutaneous intervention or thrombolytic drug therapy is well established. Because atherosclerosis is a common pathway to acute MI and acute ischemic stroke, modifying associated known risk factors is required for primary and secondary prevention of both conditions. Pharmacologic therapies recommended for secondary prevention include beta-blockers and angiotensin-converting enzyme inhibitors for MI, oral anticoagulants for stroke, and statins and antiplatelet agents for both conditions. Aspirin is recommended for preventing recurrence of both MI and stroke; agents inhibiting the adenosine diphosphate pathway of platelet activation, such as ticlopidine and clopidogrel, are also beneficial. Recent studies suggest the benefits associated with adding aspirin to clopidogrel do not outweigh the significant increase in bleeding risk. The synergistic effects of aspirin plus extended-release dipyridamole make this combination twice as effective than aspirin alone in secondary prevention of ischemic stroke. An ongoing study is directly comparing the combination of aspirin plus extended-release dipyridamole with clopidogrel for the prevention of recurrent stroke
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