Motor skill learning in the middle-aged: limited development of motor chunks and explicit sequence knowledge

The present study examined whether middle-aged participants, like young adults, learn movement patterns by preparing and executing integrated sequence representations (i.e., motor chunks) that eliminate the need for external guidance of individual movements. Twenty-four middle-aged participants (aged 55–62) practiced two fixed key press sequences, one including three and one including six key presses in the discrete sequence production task. Their performance was compared with that of 24 young adults (aged 18–28). In the middle-aged participants motor chunks as well as explicit sequence knowledge appeared to be less developed than in the young adults. This held especially with respect to the unstructured 6-key sequences in which most middle-aged did not develop independence of the key-specific stimuli and learning seems to have been based on associative learning. These results are in line with the notion that sequence learning involves several mechanisms and that aging affects the relative contribution of these mechanisms

Dutch Norms for the Eyberg Child Behavior Inventory: Comparisons with other Western Countries

The Eyberg Child Behavior Inventory (ECBI) is one of the most widely used and well-validated parent rating scales for children’s disruptive behavior. This screening instrument is a short, targetted and easy to implement inventory with good psychometric properties and is normed for different countries, among which the United States, Spain, Sweden and Norway. The ECBI has been successfully used for research and clinical purposes, in several countries including The Netherlands. To date, Dutch studies have relied on Scandinavian or US norm scores. However, this may be problematic because of cross-cultural differences in the degree to which certain behaviors are seen as problematic by parents. The main goal of this paper therefore was to obtain norm scores for The Netherlands among 6462 Dutch children aged 4 to 8 years (M age = 6.37 years; SD = 1.32; 50.6% boys). In line with previous research, we found small differences on the mean sum scores across children of different ages (intensity scale) and gender (intensity and problem scale). Therefore, Dutch norm scores were provided age- and gender specific. Our results showed that disruptive behavior of children in the most rural areas was reported as occurring less frequently and was seen as less problematic by parents compared to the disruptive behavior of children in less rural areas. Finally, we found that Dutch norm scores on the ECBI were significantly lower than US norm scores, and significantly higher on the intensity scale (but not the problem scale) than Norwegian and Swedish norm scores

Simultaneous yeast–bacteria inoculum. A feasible solution for the management of oenological fermentation in red must with low nitrogen content

The simultaneous inoculum of yeasts and bacteria is a feasible solution for improving fermentation in wines with a harsh chemical composition, capable of inhibiting microbial activity. Considering the risk of wine spoilage due to lactic bacteria, co-inoculum is suggested in white wines with a low pH. However, climate change has also caused problems in achieving malolactic fermentation in red wines, due to the high concentration of ethanol and the low nutrient content. In this work, 5 pairs of commercial oenological starters were tested in simultaneous fermentation, using 4 red musts with a low nitrogen content, and compared with a traditional winemaking process. The simultaneous inoculum caused a slowdown in the activity of yeasts, although no problems in the accomplishment of alcoholic fermentations were observed. More reliable malolactic fermentation was performed in the co-inoculum trials, while, in traditional winemaking, some failures in the degradation of malic acid were observed. Microbiological analyses agreed with these observations. No differences were found in yeast density during alcoholic fermentation, demonstrating the absence of negative interaction between the yeast and the bacteria. However, simultaneous fermentation is not without risks; the highest increases of acetic acid were noted in the co-inoculum trials. The addition of yeast and bacteria to must with a serious lack of nutrients would appear to be a promising alternative to traditional fermentation; however, careful control of the chemical composition of must is mandatory to obtain reliable microbiological activity in the first stages of winemaking