The concentrations and isotopic composition of He, Ne and Ar in 29 chondrites and 1 achondrite have been determined. Detailed accounts of the experimental technique used and the reproducibility and accuracy obtained are given. The U,Th-He4, and K-Ar ages derived from our results are in agreement with the already known age distributions of the different chondrite classes. Our measurements have r...

PURPOSE This study was conducted to determine the distributions of the polyp detection rate (PDR) and the adenoma detection rate (ADR) according to age by analyzing the polypectomy results. METHODS A total of 10,098 patients who underwent a colonoscopy in 2013 were included in this study. Chi-square and logistic regression statistical analyses were performed using SPSS ver. 19. RESULTS The ...

[1] The long-term soil carbon dynamics may be approximated by networks of linear compartments, permitting theoretical analysis of transit time (i.e., the total time spent by a molecule in the system) and age (the time elapsed since the molecule entered the system) distributions. We compute and compare these distributions for different network configurations, ranging from the simple individual c...

In this paper, an entropy-based method is proposed to forecast the demographical changes of countries. We formulate the estimation of future demographical profiles as a constrained optimization problem, anchored on the empirically validated assumption that the entropy of age distribution is increasing in time. The procedure of the proposed method involves three stages, namely: 1) Prediction of ...

It is widely known that shifts of cohort fertility schedule can produce misleading trends in period TFR. This note shows that such a “tempo bias” can occur in age-specific mortality as well: if the age distribution of cohort deaths shifts toward older (younger) ages, the period age-specific death rate is biased downward (upward). 1 Laboratory of Populations, Rockefeller University, 1230 York Av...

OBJECTIVE To examine how the relaxation of the one child policy and policies to reduce caesarean section rates might have affected trends over time in caesarean section rates and perinatal and pregnancy related mortality in China. DESIGN Observational study. SETTING China's National Maternal Near Miss Surveillance System (NMNMSS). PARTICIPANTS 6 838 582 births at 28 completed weeks or mor...

[1] In high latitudes, changes in climate impact fire regimes and snow cover duration, altering the surface albedo and the heating of the regional atmosphere. In the western Arctic, under four scenarios of future climate change and future fire regimes (2003–2100), we examined changes in surface albedo and the related changes in regional atmospheric heating due to: (1) vegetation changes followi...

As humans expand into natural environments, populations of wild organisms may become relegated to marginal habitats at the boundaries of their distributions. In the ocean, mesophotic coral ecosystems (30-150 m) at the depth limit of photosynthetic reefs are hypothesized to act as refuges that are buffered from anthropogenic and natural disturbances, yet the viability and persistence of subpopul...

BACKGROUND Few prospective studies have attempted to estimate the rate of decline of essential tremor (ET) and these were over a relatively short time period (less than 10 years). We performed a long-term study of severity stages in ET using the Glass Scale scoring system. METHODS Fifty consecutive patients with severe ET were included. We retrospectively obtained Glass Scale scores throughou...

BACKGROUND The number of older adults in the criminal justice system is rapidly increasing. While this population is thought to experience an early onset of aging-related health conditions ("accelerated aging"), studies have not directly compared rates of geriatric conditions in this population to those found in the general population. The aims of this study were to compare the burden of geriat...