126 cases of retinal breaks treated in our department by photocoagulation during a period of 10 years (1963-1973) were selected for a close annual follow-up. Eliminated from the study were cases of macular holes, breaks which developed in an eye after retinal detachment surgery, and cases in which a close follow-up was impossible for various reasons. The study includes symptomatic retinal break...

Memory shows age-related decline. According to the current prevailing theoretical model, encoding of memories relies on modifications in the strength of the synapses connecting the different cells within a neuronal network. The selective increases in synaptic weight are thought to be biologically implemented by long-term potentiation (LTP). Here, we report that tetanic stimulation of afferent f...

APPENDIX 1. DATA I follow Christiano, Eichenbaum, and Vigfusson (2003) and use BLS data on hours and labor productivity for the business economy. The BLS population data have occasional discrete jumps: When the BLS obtains new information on the population (e.g., at decennial censuses), it does not revise previous data. I use a series adjusted at the Federal Reserve Bank of Chicago that smoothe...

We develop an easy-to-implement method for forecasting a stationary autoregressive fractionally integrated moving average (ARFIMA) process subject to structural breaks with unknown break dates. We show that an ARFIMA process subject to a mean shift and a change in the long memory parameter can be well approximated by an autoregressive (AR) model and suggest using an information criterion (AIC o...

The classical random walk of which the one-step displacement variable u has a rst nite negative moment is considered. The R.W. possesses an unique stationary distribution; x is a random variable with this distribution. It is assumed that the righthand and/or the lefthand tail of the distribution of u are heavy-tailed. For the type of heavy-tailed distribution considered in this study a contract...

High concentration of NaCl increases DNA breaks both in cell culture and in vivo. The breaks remain elevated as long as NaCl concentration remains high and are rapidly repaired when the concentration is lowered. The exact nature of the breaks, and their location, has not been entirely clear, and it has not been evident how cells survive, replicate, and maintain genome integrity in environments ...