The effects of presentation frequency of summary and average KR in the acquisition and retention of a motor skill.

Summary KR is a feedback scheduling method of withholding feedback for a set number of trials in a block then presenting feedback for each trial via a graphical presentation. The feedback presented represents the difference between the actual movement and the goal of the task. Average KR is an average of the error values over the prescribed trials presented as a single graphical value. The present study examined a multifaceted approach to understanding the summary effect. Subjects received feedback after every fifth trial in acquisition for a feedback presentation of 18%. Subjects either received information about the last 5, 10, or 15 trials presented as an average or summary presentation. Subjects performed a simple ball positioning task with a 1000 ms goal movement time. For the acquisition phase the group receiving KR following every trial was found to have significantly lower $\vert$CE$\vert$ values compared to all the other conditions for only the first three blocks of acquisition. A block effect was also reported with groups becoming more consistent and accurate with practice. Subjects maintained significant consistency over the 10 minute and the 2 day retention intervals. Surprisingly, further ANOVA\u27s of the independent variables excluding the group receiving KR after every trial, revealed the summary condition to be more consistent than the average condition in acquisition performance. Further ANOVA\u27s on both retention tests yielded no significant effects of $\vert$CE$\vert$ or VE. The lack of significant effects of the independent variables are discussed in terms of the effects of task, number of trials summarized/averaged, presentation frequency, type of feedback, and the guidance hypothesis. (Abstract shortened by UMI.)Dept. of Kinesiology. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1995 .P37. Source: Masters Abstracts International, Volume: 34-06, page: 2337. Adviser: Patricia Weir. Thesis (M.H.K.)--University of Windsor (Canada), 1996

Examining peer-controlled KR schedules during the learning of a movement-timing task as a function of task experience.

Learners can be provided with feedback in the form of knowledge of results (KR), under self-controlled and peer-controlled schedules. Recently, McRae, Hansen, and Patterson (2015), identified that inexperienced peers can provide KR that can facilitate motor skill acquisition. However, it is currently unknown whether previous task experience differentially impacts how peers present learners with KR and whether this KR impacts motor skill acquisition. In the present study, participants were randomly assigned to become inexperienced peer facilitators, learners with an inexperienced peer, learners with self-control who later became experienced peers, learners with an experienced peer, or learners in a control group. During acquisition learners completed a serial-timing task with a goal of 2500ms and returned approximately twenty four hours later for a delayed retention, time transfer, and pattern transfer test. We predicted that during the delayed tests, learners with self-control would outperform all other groups. Furthermore, we predicted that learners who received KR from experienced peers would outperform learners who received KR from inexperienced peers. However, our results indicated that participants who received peer-controlled and self-controlled KR schedules learned the task in an equivalent manner. Thus, our results are novel as they identify that inexperienced peers can provide KR that is as effective as KR provided by experienced peers and KR requested under self-controlled conditions

On Whether Task Experience of the Peer Differentially Impacts Feedback Scheduling and Skill Acquisition of a Learner

Previous research has shown that peers without task experience provided knowledge of results (KR) as effectively as performers who self-controlled their own KR schedule ( McRae et al., 2015 ). In the present experiment, a group of participants first practiced a motor task while self-controlling their KR during a defined acquisition period. Twenty-four hours after their last retention trial, these participants with motor experience then provided KR to a learner during their skill acquisition. Participants were required to learn a serial-timing task with a goal of 2,500 ms. Participants completed a defined acquisition period and then returned 24 h later for a retention test. In retention, learners who received KR from experienced peers were predicted to outperform learners who received KR from inexperienced peers. The results showed that performers learned the task similarly, independent of the peer’s previous task experience. However, the peer groups differed in their frequency of providing KR to the learner and showed a discrepancy between their self-reported KR provision strategy and when they actually provided KR. The results have theoretical implications for understanding the impact of self-control in motor learning contexts.Brock University Library Open Access Publishing Fun

Muscle ring finger protein-1 inhibits PKCε activation and prevents cardiomyocyte hypertrophy

Much effort has focused on characterizing the signal transduction cascades that are associated with cardiac hypertrophy. In spite of this, we still know little about the mechanisms that inhibit hypertrophic growth. We define a novel anti-hypertrophic signaling pathway regulated by muscle ring finger protein-1 (MURF1) that inhibits the agonist-stimulated PKC-mediated signaling response in neonatal rat ventricular myocytes. MURF1 interacts with receptor for activated protein kinase C (RACK1) and colocalizes with RACK1 after activation with phenylephrine or PMA. Coincident with this agonist-stimulated interaction, MURF1 blocks PKCε translocation to focal adhesions, which is a critical event in the hypertrophic signaling cascade. MURF1 inhibits focal adhesion formation, and the activity of downstream effector ERK1/2 is also inhibited in the presence of MURF1. MURF1 inhibits phenylephrine-induced (but not IGF-1–induced) increases in cell size. These findings establish that MURF1 is a key regulator of the PKC-dependent hypertrophic response and can blunt cardiomyocyte hypertrophy, which may have important implications in the pathophysiology of clinical cardiac hypertrophy

Effects of Sphingosine-1-Phosphate on Neural Differentiation and Neurite Outgrowth in Neuroblastoma Cells

Sphingosine-1-phosphate (S1P) is emerging as a new class of second messenger involved in cellular proliferation, differentiation, and apoptosis and is implicated in diverse physiological functions. Despite many studies on the biological functions of S1P, however, little is known about its role in neuronal differentiation. By use of reverse transcription-polymerase chain reaction and immunostaining, this study aimed to explore whether S1P can differentiate neuroblastoma cells into neural cells. After incubation with 1 uM or 10 uM S1P, the number of neurite-bearing cells increased. Furthermore, the neuroblastoma cells revealed immunoreactivity for neural-specific markers such as GAP43, NFH, and SYP by immunostaining. The expression of NFH, MAP2, SYP, NeuroD1, and SYT mRNA, which is specific for neurons, was increased as shown by RT-PCR studies. The results of this study suggest that that S1P can induce neuronal differentiation and may be a good candidate for the treatment of neurodegenerative diseases

Diagnosing Small Hepatic Cysts on Multidetector CT: an Additional Merit of Thinner Coronal Reformations

OBJECTIVE: We wanted to validate the additional merit of the thinner coronal reformation images from multidetector CT (MDCT) for making the diagnosis of hepatic cysts. MATERIALS AND METHODS: For the 90 benign hepatic cysts confirmed on MRI, the transverse (5-mm thickness) and additional coronal (2-mm thickness) reformation images from MDCT were compared with each other in terms of the Hounsfield units (HUs) and the size of each hepatic cyst. RESULTS: THE ATTENUATIONS (MEAN: 17.2 HUs, standard deviation: ± 14.4) on the thinner coronal images were significantly lower than those (mean: 40.7 HUs; standard deviation: ± 20.6) on the thicker transverse images for the small hepatic cysts (≤ 10 mm on the transverse image, p < 0.01). Twenty-three (79%) of the 29 cysts between 5 mm and 10 mm and 21 (51%) of 41 lesions up to 5 mm showed a mean HU value of 20 or less on the coronal reformation images. CONCLUSION: By reducing the partial volume effect, routine coronal reformation of MDCT with a thinner section thickness can provide another merit for making a confidential diagnosis of many small sub-centimeter hepatic cysts, and these small cysts are not easily characterized on the conventional transverse images.ope

Noninvasive monitoring of treatment response in a rabbit cyanide toxicity model reveals differences in brain and muscle metabolism

Noninvasive near infrared spectroscopy measurements were performed to monitor cyanide (CN) poisoning and recovery in the brain region and in foreleg muscle simultaneously, and the effects of a novel CN antidote, sulfanegen sodium, on tissue hemoglobin oxygenation changes were compared using a sub-lethal rabbit model. The results demonstrated that the brain region is more susceptible to CN poisoning and slower in endogenous CN detoxification following exposure than peripheral muscles. However, sulfanegen sodium rapidly reversed CN toxicity, with brain region effects reversing more quickly than muscle. In vivo monitoring of multiple organs may provide important clinical information regarding the extent of CN toxicity and subsequent recovery, and facilitate antidote drug development

Giant Cell Arteritis Presenting as Small Bowel Infarction

Giant cell arteritis predominantly affects cranial arteries and rarely involves other sites. We report a patient who presented with small bowel obstruction because of infarction from mesenteric giant cell arteritis. She had an unusual cause of her obstruction and a rare manifestation of giant cell arteritis. In spite of aggressive therapy with steroids, she died a month later because of multiple complications. We discuss the diagnosis and management of small bowel obstruction and differential diagnosis of vasculitis of the gastrointestinal tract. We were able to find 11 cases of bowel involvement with giant cell arteritis in the English literature. This case report illustrates that giant cell arteritis can be a cause of small bowel obstruction and bowel infarction. In the proper clinical setting, vasculitides need to be considered early in the differential diagnosis when therapy may be most effective

Nonpharmacological management and psychosocial support for children and adolescents with type 1 diabetes

Compared to that in the Caucasian population, type 1 diabetes mellitus (T1DM) incidence rates are very low in Koreans. Therefore, compared to the recent development of pharmacological therapy applicable to Korean children with T1DM, interest in nonpharmacological therapy and psychosocial support systems remains low, as is the development of Korean-style T1DM education programs for therapeutic application. Children who have been newly diagnosed with diabetes are placed in completely new environments for treatment. For appropriate control of diabetes, patients have to self-monitor blood glucose levels and inject insulin several times a day and must use extreme self-control when they eat foods to avoid increases in blood glucose levels. Blood glucose excursions resulting from impaired pancreatic β cell functions cause mental stress due to vague fears of chronic complications of diabetes. In addition, children with diabetes cannot be excluded from the substantial amount of studies required of Korean adolescents, and the absolute shortage of time for ideal control of diabetes adds to their mental stress. Many of these patients are psychologically isolated in school where they spend most of their time, and they are not appropriately considered or supported with respect to blood glucose control in many cases. In this respect, this author will introduce some of the newest views on nonpharmacological therapy and psychosocial support systems that account for important parts of T1DM management and seek measures to apply them in conformity with the social characteristics of Korea