Transient unexpected improvement of AV conduction: What is the mechanism?

This ECG was recorded from a 93 year old patient with a previously documented third degree AV block and an underlying LBBB. The twelve lead ECG demonstrates sinus bradycardia at a rate of 52 beats per minute, a PR interval of 230 milliseconds, and a left bundle branch block (Figure 1). In figure 2, a rhythm strip of leads V1, II and V5 shows sinus rhythm with AV block. Note that only P waves in the T wave of the paced beat are conducted. The non-conducted P waves are followed by ventricular paced beats at an escape interval of 1200 milliseconds

A Rare, Late Complication after Automated Implantable Cardioverter-Defibrillator Placement

This article describes an interesting case of automated implantable cardioverter defibrillator (AICD) extrusion fifteen months after implantation. The case report is followed by a discussion of the causes and treatment of skin erosion following pacemaker/AICD insertion

Paths to prosperity: knowledge is key for Fourth District states

Even as per capita income has increased across the United States, differences among states’ incomes remain. What are the sources of these remaining differences? This Commentary identifies and analyzes the key factors—patents, educational attainment, and industry structure—that influence income-growth rates and thus per capita incomes. It also explores where the Fourth District falls in relation to other states and the country as a whole.Economic development ; Income ; Education - Economic aspects

Normal subgroups of diffeomorphism and homeomorphism groups of R^n and other open manifolds

We determine all the normal subgroups of the group of C^r diffeomorphisms of R^n, r = 1,2,...,infinity, except when r=n+1 or n=4, and also of the group of homeomorphisms of R^n (r=0). We also study the group A_0 of diffeomorphisms of an open manifold M that are isotopic to the identity. If M is the interior of a compact manifold with nonempty boundary, then the quotient of A_0 by the normal subgroup of diffeomorphisms that coincide with the identity near to a given end e of M is simple.Comment: This version corrects an error regarding the diffeomorphism groups of R^1, since the line has two ends, in contrast to higher dimension

State growth empirics: the long-run determinants of state income growth

Real average U.S. per capita personal income growth over the last 65 years exceeded a remarkable 400 percent. Also notable over this period is that the stark income differences across states have narrowed considerably: In 1939 the highest income state’s per capita personal income was 4.5 times the lowest, but by 1976 this ratio had fallen to less than 2 times. Since 1976, the standard deviation of per capita incomes at the state level has actually risen, as some higher-income states have seen their income levels rise relative to the median of the states. A better understanding of the sources of these relative growth performances should help to characterize more effective economic development strategies, if income growth differences are predictable. In this paper, we look for statistically and economically significant growth factors by estimating an augmented growth model using a panel of the 48 contiguous states from 1939 to 2004. Specifically, we control for factors that previous researchers have argued were important: tax burdens, public infrastructure, size of private financial markets, rates of business failure, industry structure, climate, and knowledge stocks. Our results, which are robust to a wide variety of perturbations to the model, are easily summarized: A state’s knowledge stocks (as measured by its stock of patents and its high school and college attainment rates) are the main factors explaining a state’s relative per capita personal income.Economic development ; Income ; Education - Economic aspects

The heating value and proximate analyses of Missouri coals

"March, 1911.""A Reprint.