Decline in extinction rates and scale invariance in the fossil record

We show that the decline in the extinction rate during the Phanerozoic can be accurately parameterized by a logarithmic fit to the cumulative total extinction. This implies that extinction intensity is falling off approximately as the reciprocal of time. We demonstrate that this observation alone is sufficient to explain the existence of the proposed power-law forms in the distribution of the sizes of extinction events and in the power spectrum of Phanerozoic extinction, results which previously have been explained by appealing to self-organized critical theories of evolutionary dynamics.Comment: 11 pages including 3 postscript figures, typeset in LaTeX 2e using the Elsevier macro package elsart.cl

The Graying of Global Population and Its Macroeconomic Consequences

Population aging is emerging as a major demographic trend in many countries, with potentially important implications for a variety of macroeconomic issues. Notwithstanding these challenges, population aging will likely have a comparatively modest effect on economic growth. Although the changed age distribution would be expected to cause the labor force participation rate to decrease, the ratio of labor force to population will actually increase in most countries. This will occur because the lower youth dependency rate and the increased rate of female labor force participation – both of which may reasonably be expected to follow from the fertility rate declines that are driving population aging – will counterbalance the shifting of adults toward older ages at which labor force participation and savings rates are lower. Behavioral and policy responses to population aging – including higher savings for retirement, a higher rate of human capital accumulation, alternate pension funding plans, and (possibly) increased migration from labor-abundant to labor-scarce countries – also suggest that population aging need not necessarily significantly impede economic growth.Global population, macroeconomics, aging

Disease and Development Revisited

In a recent paper, Acemoglu and Johnson (2007) argue that the large increases in population health witnessed in the 20th century may have lowered income levels. We argue that this result depends crucially on their assumption that initial health and income do not affect subsequent economic growth. Using their data we reject this assumption in favor of a model of conditional convergence, with income adjusting to its steady state over time. We show that, allowing for conditional convergence, exogenous improvements in health due to technical advances associated with the epidemiological transition appear to have increased income levels.Disease, development, economic growth, health

The Effect of Social Security Reform on Male Retirement in High and Middle Income Countries

We analyze panel data for 40 countries over the period 1970-2000 to examine the effect of social security reforms on the labor supply of older men. The data show a trend towards earlier retirement that can be explained by rising income levels. We find that the average retirement age rises significantly when the normal, or early, social security eligibility age rises, the pension benefits for postponing retirement are increased, or the system shifts from defined benefits to defined contributions. A package of social security reforms is capable of substantially increasing the labor supply of older men.Social security reform, retirement, high and middle income countries

Can the stock market tell bank supervisors anything they don't already know?

This article provides evidence consistent with recent policy proposals calling for a greater role for market forces in promoting a safe and sound financial system. The authors' empirical results indicate a measure of expected default probability distilled from equity prices helps predict the financial condition of individual banking organizations, as reflected in their supervisory ratings. Moreover, the stock market data have predictive power over and above the information in the quarterly financial statements available to supervisors between inspections. These findings suggest financial markets can provide useful information to supplement supervisory assessments, particularly between inspections, and point to the value of additional research to further clarify the information content of market prices and quantities.Banks and banking ; Bank examination ; Bank supervision

Relative entropy as a measure of inhomogeneity in general relativity

We introduce the notion of relative volume entropy for two spacetimes with preferred compact spacelike foliations. This is accomplished by applying the notion of Kullback-Leibler divergence to the volume elements induced on spacelike slices. The resulting quantity gives a lower bound on the number of bits which are necessary to describe one metric given the other. For illustration, we study some examples, in particular gravitational waves, and conclude that the relative volume entropy is a suitable device for quantitative comparison of the inhomogeneity of two spacetimes.Comment: 15 pages, 7 figure

Cats with thermal burn injuries from California wildfires show echocardiographic evidence of myocardial thickening and intracardiac thrombi.

Recent increases in the prevalence and severity of wildfires in some regions have resulted in an increased frequency of veterinary burn patients. Few studies exist regarding diagnostics and management of burn wounds in veterinary patients and current knowledge is extrapolated from human literature and research models. Post-burn cardiac injury is a common finding and predictor of mortality in human patients and echocardiography is an important tool in monitoring response to therapy and predicting outcome. We describe the notable findings from cats naturally exposed to California wildfires in 2017 and 2018. Domestic cats (n = 51) sustaining burn injuries from the Tubbs (2017) and Camp (2018) wildfires were prospectively enrolled and serial echocardiograms and cardiac troponin I evaluations were performed. Echocardiograms of affected cats revealed a high prevalence of myocardial thickening (18/51) and spontaneous echocardiographic contrast and thrombi formation (16/51). Forty-two cats survived to discharge and 6 died or were euthanized due to a possible cardiac cause. For the first time, we describe cardiovascular and coagulation effects of thermal burn and smoke inhalation in cats. Further studies in veterinary burn victims are warranted and serve as a translational research opportunity for uncovering novel disease mechanisms and therapies

Nitrous oxide and methane in the Atlantic Ocean between 50 degrees North and 52 degrees South: Latitudinal distribution and sea-to-air flux

We discuss nitrous oxide (N2O) and methane (CH4) distributions in 49 vertical profiles covering the upper 300 m of the water column along two 13,500 km transects between 50°N and 52°S during the Atlantic Meridional Transect (AMT) programme (AMT cruises 12 and 13). Vertical N2O profiles were amenable to analysis on the basis of common features coincident with Longhurst provinces. In contrast, CH4 showed no such pattern. The most striking feature of the latitudinal depth distributions was a well-defined “plume” of exceptionally high N2O concentrations coincident with very low levels of CH4, located between 23.5°N and 23.5°S; this feature reflects the upwelling of deep waters containing N2O derived from nitrification, as identified by an analysis of N2O, apparent oxygen utilization (AOU) and NO3-, and presumably depleted in CH4 by bacterial oxidation. Sea-to-air emissions fluxes for a region equivalent to 42% of the Atlantic Ocean surface area were in the range 0.40–0.68 Tg N2O yr-1 and 0.81–1.43 Tg CH4 yr-1. Based on contemporary estimates of the global ocean source strengths of atmospheric N2O and CH4, the Atlantic Ocean could account for 6–15% and 4–13%, respectively, of these source totals. Given that the Atlantic Ocean accounts for around 20% of the global ocean surface, on unit area basis it appears that the Atlantic may be a slightly weaker source of atmospheric N2O than other ocean regions but it could make a somewhat larger contribution to marine-derived atmospheric CH4 than previously thought