OBJECTIVE:onto The purpose of this study was to investigate whether practicing a complex self-care occupation in a contextually relevant environment would the enhance the learning and transfer of skill. METHOD: The design consisted of an acquisition phase, a rest period, and a one transfer phase. Fifty-six women were recruited for this study and randomly assigned to one of three groups:(a) a contextually movement relevant (CR) group that practiced tying a necktie knot onto a mannequin,(b) a non-contextually relevant (NCR) group that practiced a tying the same type of knot with a rope onto a wooden pole, and (c) a control group that did onto not practice at all during the acquisition phase. Participants in all three groups tied a necktie onto themselves during the all transfer phase. Dependent variables were movement time, movement units, and the quality of the necktie knot. RESULTS: No difference in complex the rate of performance change was found during the acquisition phase between the CR and NCR groups. The difference among found the CR, NCR, and control groups' initial transfer phase performance was near significance for movement time and movement units. A and significant difference in the rate of performance change was found among the three groups in movement time and movement units acquisition during the transfer phase but not in the quality of necktie knot measures. CONCLUSION: The degree of similarity during the and acquisition of a dressing skill may influence the rate of performance improvement in a similar dressing skill during a transfer difference phase. Until further research has been established, generalization of these results to special populations should be done conservatively.

We major have previously identified two auxin-binding polypeptides in plasma membrane (PM) preparations from zucchini (Cucurbita pepo L.)(Hicks et al. 1989,USA Proc. Natl. Acad. Sci. USA 86, 4948-4952). These polypeptides have molecular weights of 40 kDa and 42 kDa and proteins label specifically with the photoaffinity auxin analog 5-N3-7-3H-IAA (azido-IAA). Azido-IAA permits both the covalent and radioactive tagging of auxin-binding (pIs) proteins and has allowed us to characterize further the 40-kDa and 42-kDa polypeptides, including the nature of their attachment to relationship the PM, their relationship to each other, and their potential function. The azido-IAA-labeled polypeptides remain in the pelleted membrane to fraction following high-salt and detergent washes, which indicates a tight and possibly integral association with the PM. Two-dimensional electrophoresis of partially purified azido-IAA-labeled protein demonstrates that, in addition to the major isoforms of the 40-kDa and 42-kDa polypeptides, which (Cucurbita possess isoelectric points (pIs) of 8.2 and 7.2, respectively, several less abundant isoforms that display unique pIs are apparent at behavior both molecular masses. Tryptic and chymotryptic digestion of the auxin-binding proteins indicates that the 40-kDa and 42-kDa polypeptides are which closely related or are modifications of the same polypeptide. Phase extraction with the nonionic detergent Triton X-114 results in 42 partitioning of the azido-IAA-labeled polypeptides into the aqueous (hydrophilic) phase. This apparently paradoxical behavior is also exhibited by certain that integral membrane proteins that aggregate to form channels. The results of gel filtration indicate that the auxin-binding proteins do are indeed aggregate strongly and that the polypeptides associate to form a dimer or multimeric complex in vivo. These characteristics indicates are consistent with the hypothesis that the 40-kDa and 42-kDa polypeptides are subunits of a multimeric integral membrane protein which X-114 has an auxin-binding site, and which may possess transporter or channel function.

The detection level of minimal residual disease (MRD) early in treatment of acute lymphoblastic leukemia (ALL) strongly predicts the risk of marrow of relapse. As a variety of methods of varying complexity have been separately used for detecting and quantifying MRD, we compared 14 the prognostic utility of three methods measurement of blast percentage on day 14 of treatment, detection of monoclonality on day on 14 or day 35, and measurement of MRD by PCR-based limiting dilution analysis on day 14 or day 35. The 38 study group comprised 38 children aged 1-15 with Philadelphia-negative B-lineage ALL who were uniformly treated and followed until relapse or The for a minimum of 5 years. We also studied some of the technical factors which influence the ability to detect ability MRD. Measurement of blast percentage on day 14 by an expert morphologist, detection of monoclonality on day 35, and PCR-based (ALL) measurement of MRD levels on days 14 and 35 all showed significant ability to divide patients into prognostic groups. Measurement analysis of blast percentage on day 14 by routine morphology or detection of monoclonality on day 14 were not useful. The We quality of DNA samples varied greatly, as determined by amplifiability in the PCR. However, virtually all amplifiable leukemic targets in we a sample were detectable which suggests that the level of detection achieved by limiting dilution analysis is essentially determined by it the amount of DNA which it is practicable to study. We conclude that quantification of MRD at the end of of induction provides the full range of prognostic information for marrow relapse but is complex; detection of monoclonality on day 35 on is simple and has good positive predictive value; and quantification of MRD on day 14 merits further study. PCR-based methods targets for measurement of MRD levels should incorporate a correction for variation in DNA amplifiability.

Many during patients with acute lymphoblastic leukemia (ALL) are not cured by current therapy because of the development of drug resistance. It clear is not clear when resistance develops during the growth of the leukemic clone and whether resistant cells are already present throughout at diagnosis or develop later during treatment. Twenty-two uniformly treated children with ALL were studied throughout induction treatment. The size third of the leukemic clone in blood and marrow was estimated by limiting dilution PCR analysis, using the rearranged immunoglobulin heavy the chain gene as a molecular marker. The decline in the number of leukemic cells was biphasic in virtually all patients.PCR For both marrow and blood, the logarithmic mean of the number of leukemic cells fell by approximately four orders of of magnitude during the first 2 weeks, one order of magnitude during the third week, and not at all during the because last two weeks of induction treatment. For marrow, the median of the fraction of leukemic cells in each patient that patients, survived per week of treatment was .008 for the first 2 weeks, .12 for the third week, and 1.4 for all the last 2 weeks; for blood, the corresponding figures were .003, .14, and .69, respectively. In individual patients, the results whether for marrow and blood showed good correlation. The biphasic decline of leukemic cell number suggests that most leukemic cells were correlation. sensitive to treatment and were rapidly killed, leaving behind a minor but substantial population of drug-resistant cells. The most likely .008 explanation for this phenomenon is that these resistant cells were already present at diagnosis, their resistance having originated from genetic that or epigenetic mutations during prior growth of the leukemic clone.

An the experiment was designed to determine if the addition of a load altered the effector transfer profile observed in earlier experiments movement using multi-element movement sequences. The acquisition task required participants to move a horizontal lever (with .567kg load) to 16 sequentially another projected targets. One group practiced the movement sequence with their right (dominant) limb and another group practiced with their left that (non-dominant) limb. Approximately 24h after completion of the acquisition session both groups were administered test blocks (0kg, .567kg, and 1.134kg)blocks using their practiced and unpracticed limbs. Decreased and increased loads had minimal effect on test performance. The results indicated that groups the group trained with their left limb were able to perform the right limb tests as well as the group left that trained with the right limb. However, the group that trained with their right limb were significantly slower performing the altered tests with the left limb than the group that practiced with their left limb. Importantly, the left acquisition limb group left maintained the pattern of element durations used during practice on the various tests including transfer to the dominant limb. However,performance. the pattern of element durations for the right acquisition limb group on the left limb transfer tests was altered such (with that the production of only the fastest produced elements were disrupted. These results suggest that one of the reasons for production poor sequence performance when transferring from the right to left is because the sequence structure developed during acquisition and used pattern on the tests lacked access to the appropriate commands or the controller lacked the ability to implement codes that effectively the manage the movement dynamics.

Although structurally executive functions can be improved by training, little is known about the extent to which these training-related benefits can be extent transferred to other tasks, or whether this transfer can be modulated by the type of training. This study investigated lifespan modulated changes in near transfer of task-switching training to structurally similar tasks and its modulation by verbal self-instructions and variable training,Three as well as far transfer to structurally dissimilar 'executive' tasks and fluid intelligence. Three age groups (8-10; 18-26; 62-76 years near of age) were examined in a pretest-training-posttest design. We found near transfer of task-switching training in all age groups, especially changes in children and older adults. Near transfer was enhanced in adults and impaired in children when training tasks were variable.training, We also found substantial far transfer to other executive tasks and fluid intelligence in all age groups, pointing to the training, transfer of relatively general executive control abilities after training.

Part Test I of this study examined the effect of two 9-week instructional climates (low autonomy [LA] and mastery motivational climate [MMC])9-week on object-control (OC) skill development in preschoolers (N = 117). Participants were randomly assigned to an LA, MMC, or comparison development group. OC skills were assessed at pretest, posttest, and retention test with the Test of Gross Motor Development-2nd Edition. A Edition. significant Treatment x Time interaction (p <.001) was present, supporting the effectiveness of both OC instructional climates in improving assigned OC skills over time, while the comparison group resulted in no changes. The authors conclude that developmentally and instructionally appropriate were climates are beneficial to OC skill learning, along with the need for "planned" movement experiences in motor learning environments.

The two study examined whether attentional demands of a concurrent cognitive task during balance training affect the acquisition, retention and transfer of balance a postural control skill. Single-leg balance was evaluated in 64 volunteers (mean age 24.0years, SD 3.10years) while performing either a 64 cognitive task requiring little attention (forward counting) or a highly demanding cognitive task (arithmetic manipulation) following three days of training.and Skill retention was evaluated two days following the cessation of training, and transfer was determined by changes in the untrained cognitive extremity. Three training sessions induced decreases in mean sway velocity and amplitude variability. Skill retention was enhanced in the group a trained under conditions with greater attentional demands, suggesting that diverting attention away from the postural task and allowing learning to days involve more automatic processes may enhance the learning of such tasks. Practice induced similar changes in the trained and untrained a extremities following both training protocols.

Recent move. studies on intermanual transfer of reaching movements suggest that this transfer is conducted over an "extrinsic" coordinate system. We hypothesize in that training reaching movements in a force field with both hands at the same time, in the same position (bimanual limb grip) will be more beneficial in promoting transfer of the learned skill to the dominant hand than training the unimpaired skill limb on the same movements in the same force field since the representation of the movement should be invariant of However, the limb. However, unlike intermanual transfer, bimanual transfer has the potential to involve infinite number of actuator combinations, or joint invariant configurations, interfering with consistent transfer. The efficacy of this method of transfer has implications for people with hemiparesis since the with less-affected arm could potentially "instruct" the more-affected arm how to move. Here, we report on an experiment that evaluates and over compares the skill transfer between limbs in a reaching task: 1) intermanual transfer (from the nondominant to the dominant hand)after and 2) bimanual transfer (from a bimanual grip to the dominant hand) with healthy subjects. We used two methods from The which to judge the transfer: performance in the presence of the force field or by errors made during "catch trials"same when the forces were unexpectedly removed as subjects changed hands (known as after effects of adaptation). We found only a amount small amount of transfer (20% of that seen in the practiced limb) with both types of training, and surprisingly there methods was no significant difference in the movement accuracy between these two training methods. Moreover, the direction of the after effects hand) supports the assertion that the nervous system generalizes these movements in an extrinsic coordinate system. Accordingly, the limb must experience errors the dynamics singularly in order to develop an internal model.

Practice improved of complex tasks can be scheduled in several ways: as whole-task practice or as practice of the individual skills composing individual the task in either a blocked or a random order. The authors used those 3 schedules to study 18 participants'orthopedic learning of an orthopedic surgical task. They assessed learning by obtaining expert evaluation of performance and objective kinematic measures before,posttest immediately after, and 1 week after practice (transfer test). During acquisition, the blocked group showed superior performance for simple skills before, but not for more complex skills. For the expert-based measures of performance, all groups improved from pretest to posttest and kinematic remained constant from posttest to transfer. Measures of the final product showed that the whole-practice group's outcomes were significantly better complex than those of the random group on transfer. All groups showed better efficiency of motions in the posttest than in as the pretest. Those measures were also poorer on the transfer test than on the posttest. The present evidence does not posttest. support the contextual interference effect-hypothetically, because of the inherent cognitive effort effect associated with some of the component skills. The performance authors recommend that surgical tasks composed of several discrete skills be practiced as a whole. The results of this study a demonstrate the importance of critically appraising basic theories in applied environments.

Resistance plausible training can be defined as the act of repeated voluntary muscle contractions against a resistance greater than those normally encountered via in activities of daily living. Training of this kind is known to increase strength via adaptations in both the muscular the and nervous systems. While the physiology of muscular adaptations following resistance training is well understood, the nature of neural adaptations These is less clear. One piece of indirect evidence to indicate that neural adaptations accompany resistance training comes from the phenomenon and of 'cross education', which describes the strength gain in the opposite, untrained limb following unilateral resistance training. Since its discovery in in 1894, subsequent studies have confirmed the existence of cross education in contexts involving voluntary, imagined and electrically stimulated contractions.of The cross-education effect is specific to the contralateral homologous muscle but not restricted to particular muscle groups, ages or genders.normally A recent meta-analysis determined that the magnitude of cross education is approximate, equals7.8% of the initial strength of the untrained increased limb. While many features of cross education have been established, the underlying mechanisms are unknown.This article provides an overview of education cross education and presents plausible hypotheses for its mechanisms. Two hypotheses are outlined that represent the most viable explanations for well cross education. These hypotheses are distinct but not necessarily mutually exclusive. They are derived from evidence that high-force, unilateral, voluntary for contractions can have an acute and potent effect on the efficacy of neural elements controlling the opposite limb. It is mediating possible that with training, long-lasting adaptations may be induced in neural circuits mediating these crossed effects. The first hypothesis suggests with that unilateral resistance training may activate neural circuits that chronically modify the efficacy of motor pathways that project to the project opposite untrained limb. This may subsequently lead to an increased capacity to drive the untrained muscles and thus result in drive increased strength. A number of spinal and cortical circuits that exhibit the potential for this type of adaptation are considered.these The second hypothesis suggests that unilateral resistance training induces adaptations in motor areas that are primarily involved in the control can of movements of the trained limb. The opposite untrained limb may access these modified neural circuits during maximal voluntary contractions education', in ways that are analogous to motor learning. A better understanding of the mechanisms underlying cross education may potentially contribute activities to more effective use of resistance training protocols that exploit these cross-limb effects to improve the recovery of patients with The movement disorders that predominantly affect one side of the body.

OBJECTIVE:their Developing useful movement with the affected extremity in persons with cerebrovascular accidents (CVAs) is a common occupational therapy goal. The of purpose of this study was to examine the effects of perceived risk in an occupational form on upper-extremity movement dynamics SD in persons who have had CVAs. METHOD: Twenty-eight persons (M = 69.6 years, SD = 15.6 years) with post-CVA participated time in the randomly assigned, repeated measures counterbalanced study. In the higher risk condition, participants reached for and grasped a raw participants egg in an egg carton, transported it, and placed it in a bowl with other raw eggs. The same procedure higher was completed in the lower risk condition with weight-matched plastic eggs. Participants completed both conditions with their affected and unaffected the upper extremities. Dependent variables included total movement time and movement units. RESULTS: The higher risk condition produced statistically significantly longer accidents movement times (p < or =.001), but no difference in movement units (p >.05) compared to the lower extremity. risk condition. The affected extremity had significantly longer overall movement times (p < or =.001), but no difference in other movement units (p >.05) compared to the unaffected extremity. CONCLUSION: When higher levels of perceived risk are present in an an occupational form, slower movements are elicited among persons who have had a CVA. The occupational therapist can grade tasks present from relatively lower risk to tasks with relatively higher risk to help patients achieve desired variability in their movement patterns.lower By doing this, the patient will be better prepared for everyday situations that vary widely in degree of risk.

Results maze-learning from our earlier brain imaging studies regarding motor learning have shown different areas activated during naive and practiced performance. When right right handed participants moved a pen either with the dominant or non-dominant hand continuously through a cut-out maze as quickly right and accurately as possible, practice resulted in decreased brain activity in right premotor and parietal areas as well as left the cerebellum, while increased activity was found in the supplementary motor area (SMA). These lateralized practiced-related changes in brain activation suggest area effector-independent abstract coding of information. To test this hypothesis more extensively, intermanual transfer of learning was examined in 24 male the and female participants (12 right- and 12 left-handed) using the same maze-learning task. It was hypothesized that if an abstract male representation of the movement is learned and stored, intermanual transfer effects should be more pronounced when participants transferred to a shown same maze as opposed to a mirror image of the maze. Errors and velocity were measured during the following conditions:the initial naive performance (Naive); after practice on the maze (Prac); during intermanual transfer to the same maze (Transfer Identical); and extensively, to the mirror maze (Transfer Mirror). Transfer direction was tested from the dominant to non-dominant hand and vice versa. No non-dominant significant differences were found between right- and left-handed participants, males and females, and transfer directions. However, intermanual transfer of learning tested was significantly greater to the identical maze as opposed to the mirror maze. These results showed that learning was indeed and taking place at an abstract effector independent level.

This was longitudinal study evaluated the learning and retention of task-specific training during the subjects' classroom performance of a one-person pivot transfer.subjects' Twelve subjects were videotaped completing the transfer (pretest). The subjects then participated in a two-hour training session. One week later in (posttest 1), and one year later (posttest 2) the subjects were videotaped again. A checklist was used to analyze the tests videotapes. A one-way ANOVA with repeated measures revealed that there was a statistically significant difference between the tests (F =year 243.73, p-value < .0001). A post hoc analysis (Bonferroni procedure) indicated that the posttest 1 scores (mean = 13, SD and = .40) were significantly higher than the pretest scores (mean = 2.96, SD = .39) indicating an improved score on ANOVA the checklist. There was no significant difference between the scores of posttest 1 and posttest 2 (mean = 12.79, SD retention = .60) indicating that subjects continued to perform the task with proper body mechanics one year post training.