Paddlefish production : opportunities for Missouri pond and lake owners (2007)

New 7/07/3M

The possibilities of the use of N-of-1 and do-it-yourself trials in nutritional research.

BACKGROUND:N-of-1 designs gain popularity in nutritional research because of the improving technological possibilities, practical applicability and promise of increased accuracy and sensitivity, especially in the field of personalized nutrition. This move asks for a search of applicable statistical methods. OBJECTIVE:To demonstrate the differences of three popular statistical methods in analyzing treatment effects of data obtained in N-of-1 designs. METHOD:We compare Individual-participant data meta-analysis, frequentist and Bayesian linear mixed effect models using a simulation experiment. Furthermore, we demonstrate the merits of the Bayesian model including prior information by analyzing data of an empirical study on weight loss. RESULTS:The linear mixed effect models are to be preferred over the meta-analysis method, since the individual effects are estimated more accurately as evidenced by the lower errors, especially with lower sample sizes. Differences between Bayesian and frequentist mixed models were found to be small, indicating that they will lead to the same results without including an informative prior. CONCLUSION:For empirical data, the Bayesian mixed model allows the inclusion of prior knowledge and gives potential for population based and personalized inference

Introducing personalised self-management to support physical activity in elderly: a case study.

Our population is aging, leading to great challenges in healthcare. A transformation to a pro-active system, support through technology, and self-management are regularly mentioned as potential solutions. In this context, the self-management program LIFE (“living independently functioning elderly”) was started to promote physical activity in seniors. A technology-supported personalized self-management program was developed. The aim of the program is to contribute to a physically active life style. LIFE offers various modules to elderly who are at risk of functional decline. These modules contain personalized advice, recommendations and suggestions how seniors can develop or maintain a healthy behaviour and prevent functional deterioration. To restrict functional decline, activities of the program are tailored to the needs of the user. The activities are delivered preventive instead of after the functional decline has been progressed to the extent that elderly have to be institutionalised. A main aspect of the concept of the program is that elderly can choose between the various provided services, making their own decisions. LIFE offers this in an easily implementable self-management program. In this paper, the program is presented, the care pathway of operationalizing the program is described, and evaluation results are discussed. As such, this paper demonstrates the feasibility of introducing an ict-mediated self-management program in elderly care. (aut. ref.

fMRI guided rTMS evidence for reduced left prefrontal involvement after task practice.

INTRODUCTION: Cognitive tasks that do not change the required response for a stimulus over time ('consistent mapping') show dramatically improved performance after relative short periods of practice. This improvement is associated with reduced brain activity in a large network of brain regions, including left prefrontal and parietal cortex. The present study used fMRI-guided repetitive transcranial magnetic stimulation (rTMS), which has been shown to reduce processing efficacy, to examine if the reduced activity in these regions also reflects reduced involvement, or possibly increased efficiency. METHODS: First, subjects performed runs of a Sternberg task in the scanner with novel or practiced target-sets. This data was used to identify individual sites for left prefrontal and parietal peak brain activity, as well as to examine the change in activity related to practice. Outside of the scanner, real and sham rTMS was applied at left prefrontal and parietal cortex to examine their involvement novel and practiced conditions. RESULTS: Prefrontal as well as parietal rTMS significantly reduced target accuracy for novel targets. Prefrontal, but not parietal, rTMS interference was significantly lower for practiced than novel target-sets. rTMS did not affect non-target accuracy, or reaction time in any condition. DISCUSSION: These results show that task practice in a consistent environment reduces involvement of the prefrontal cortex. Our findings suggest that prefrontal cortex is predominantly involved in target maintenance and comparison, as rTMS interference was only detectable for targets. Findings support process switching hypotheses that propose that practice creates the possibility to select a response without the need to compare with target items. Our results also support the notion that practice allows for redistribution of limited maintenance resources

The experimental design.

<p>Subjects participated in one fMRI and two rTMS sessions, one for parietal and for prefrontal rTMS. Each session started with a practice session with a unique fixed target-set.</p

Effect of rTMS on reaction time.

<p>Graphs illustrate that reaction time was lower in the practiced than in the novel condition, but rTMS had no effect on reaction times. a. reaction time during prefrontal rTMS; b. reaction time during parietal rTMS.</p

Summary of the fMRI results.

<div><p>a. regions showing significant difference between novel and practice condition (red: novel < practiced, blue: practiced > novel). Three regions showed an increase in activity for the practiced condition compare to the novel condition (a. right medial superior frontal cortex (rMSFC), b. left precuneus (lPCun), c. left Angular Gyrus (lAG). </p> <p>b. Signal change (baseline: rest) for the three regions where we found higher activity for practiced targets than for novel targets. The graph shows that in all three regions activity was below resting state activity for the novel condition, and closer to resting state for the practiced condition. Thus, none of these regions showed new or increased activity in the practiced condition, compared to the novel condition. </p> <p>c. fMRI signal measured at the individual prefrontal and parietal target regions for rTMS, based on the novel-baseline contrast. Both at the prefrontal and parietal regions, subjects showed significantly lower activity for practiced than for novel target-sets. </p></div