天堂波多黎各

Standing on the white sands of Red Beach,it's hardto believe that US Navy bombers ever droned overthe surf on their way to drop explosives nearby.The beach,a semicircle(半圆形) of stark cliffs andswaying palms surrounding a sparkling azure sea,is asperfect a picture of paradise as the wallpaper in a 1970srumpus(喧闹) room。Silence is broken only by the     

Basic journal list for small hospital libraries

This Basic Journal List of forty-eight journal titles is intended as a selection guide for the librarian of the small hospital. It is based on a survey of physicians in Virginia who were asked to review journal titles contained in the 1967 edition of a list compiled by Mr. Alfred N. Brandon. The List is designed for the library in a hospital of from 100 to 300 beds and for the active clinician.     

Time series analysis of knowledge of results effects during motor skill acquisition

Time series analysis was used to investigate the hypothesis that during acquisition of a motor skill, knowledge of results (KR) information is used to generate a stable internal referent about which response errors are randomly distributed. Sixteen subjects completed 50 acquisition trials of each of three movements whose spatial-temporal characteristics differed. Acquisition trials were either blocked, with each movement being presented in series, or randomized, with the presentation of movements occurring in random order. Analysis of movement time data indicated the contextual interference effect reported in previous studies was replicated in the present experiment. Time series analysis of the acquisition trial data revealed the majority of individual subject response patterns during blocked trials were best described by a model with a temporarily stationary, internal reference of the criterion and systematic, trial-to-trial variation of response errors. During random trial conditions, response patterns were usually best described by a "White-noise" model. This model predicts a permanently stationary, internal reference associated with randomly distributed response errors that are unaffected by KR information. These results are not consistent with previous work using time series analysis to describe motor behavior (Spray & Newell, 1986).