Feedback protocol of 'fading knowledge of results' is effective for prolonging motor learning retention.

[Purpose] "Knowledge of results" (KR) is information about the success of an action relative to a goal. A reduced frequency of "knowledge of results" reportedly promotes motor learning more than a high frequency. However, the effect of gradually diminishing or increasing "knowledge of results" pattern has been rarely studied and is controversial. We investigated the effectiveness of diminishing "knowledge of results" pattern in motor learning. [Participants and Methods] Forty-six healthy adults were randomly assigned to either the 100% KR, 50% KR, or faded KR group. Participants were tasked with exerting 60% of their maximum voluntary contraction of their left shoulder flexion muscle in an isometric exercise. Participants practiced the task 20 times a day for 4 days. A pretest and posttest were conducted before and immediately after the acquisition, respectively. Retention tests were conducted 1 day, 1 week, and 2 weeks after the acquisition. [Results] The absolute error was significantly reduced in the posttest in the faded KR and 50% KR cohorts. However, there was no significant difference in the 100% KR group. In the faded KR subjects, the improvement effect was observed up to 1 week following acquisition. [Conclusion] Faded "knowledge of results" productively prolongs the effect of motor learning.

Random BAC FISH of monocot plants reveals differential distribution of repetitive DNA elements in small and large chromosome species.

BAC FISH (fluorescence in situ hybridization using bacterial artificial chromosome probes) is a useful cytogenetic technique for physical mapping, chromosome marker screening, and comparative genomics. As a large genomic fragment with repetitive sequences is inserted in each BAC clone, random BAC FISH without adding competitive DNA can unveil complex chromosome organization of the repetitive elements in plants. Here we performed the comparative analysis of the random BAC FISH in monocot plants including species having small chromosomes (rice and asparagus) and those having large chromosomes (hexaploid wheat, onion, and spider lily) in order to understand a whole view of the repetitive element organization in Poales and Asparagales monocots. More unique and less dense dispersed signals of BAC FISH were observed in species with smaller chromosomes in both the Poales and Asparagales species. In the case of large-chromosome species, 75-85% of the BAC clones were detected as dispersed repetitive FISH signals along entire chromosomes. The BAC FISH of Lycoris did not even show localized repetitive patterns (e.g., centromeric localization) of signals.

Do therapists with fewer years of clinical experience encounter more accidents? The relationship between number of years of clinical experience and number of accidents in a year.

OBJECTIVES: This study sought to determine whether therapists experience more accidents annually with increased clinical experience, and whether experiencing an accident in the first year of practice is associated with accidents in the second year of practice. METHODS: We categorized 642 therapists into five groups based on years of clinical experience (first, second, third, fourth, and 5-20 years; n=138, 112, 117, 58, and 217, respectively) and tallied the accidents they reported over an 8-year period. The difference between the five groups in the number of accidents per person per year was subjected to multiple comparisons testing using Kruskal-Wallis tests. RESULTS: Significant differences were revealed between the first year group and the 5-20 years group (p<0.01), between the second year group and the 5-20 years group (p<0.05), and between the third year group and the 5-20 years group (p<0.05). Specifically, participants in the 5-20 years group encountered fewer accidents than those in the other groups. Therapists who encountered an accident in their first year, compared with those who had not, had significantly more accidents in their second year. CONCLUSIONS: Therapists with 1-3 years of clinical experience are more likely to encounter an accident than therapists with >5 years of clinical experience. We conclude that young therapists who have experienced accidents are prone to future accidents. These findings inform the optimal allocation of educational resources to reduce the number of accidents encountered by therapists.