155 research outputs found

    The number of orthogonal permutations

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    Kinematics, Kinetics and Muscle Activity Analysis during Single-leg Drop-jump Landing Followed by an Unanticipated Task: Focusing on Differences in Neurocognitive Function

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    # Background Lower neurocognitive function is a risk factor for anterior cruciate ligament (ACL) injury. However, the mechanism by which lower neurocognitive function increases the risk of ACL injury remains unclear. # Purpose To clarify the effect of differences in neurocognitive function on landing mechanics during a single-leg drop-jump landing motion followed by an unanticipated task. # Study Design Cross-sectional study # Methods Fifteen collegiate female athletes were recruited (20.1 ± 1.3 years, 166.6 ± 7.3 cm, 60.6 ± 6.9 kg) and were divided into two groups (the high-performance (HP) group and the lower-performance (LP) group) using the median Symbol Digit Modalities Test (SDMT) score. Three-dimensional motion analysis was employed for the analysis during the experimental task of a single-leg drop-jump followed by an unanticipated landing task from a 30-cm high box. Joint angular changes of the trunk, pelvis, hip, and knee were calculated within the interval from initial contact (IC) to 40ms. Knee and hip moments were calculated as the maximum values within the interval from IC to 40ms. Surface electromyography data from key muscles were analyzed 50ms before and after IC. Independent t-tests were used to compare the effects of different neurocognitive function on the measurement items. Statistical significance was set at p < 0.05. # Results The SDMT score was significantly higher in HP group (HP: 77.9 ± 5.5; LP: 66.0 ± 3.4; p < 0.001). The LP group had a significantly greater trunk rotation angular change to the stance leg side (HP: 0.4 ± 0.8; LP: 1.2 ± 0.4; p = 0.020). There were no significant differences between the two groups in terms of joint moments, and muscle activities. # Conclusion Differences in neurocognitive function by SDMT were found to be related to differences in motor strategies of the trunk in the horizontal plane. Although trunk motion in the sagittal and frontal planes during single-leg drop-jump landing increases the ACL injury risk by affecting knee joint motion, the effect of trunk motion in the horizontal plane remains unclear. # Level of Evidence 3 © The Author

    Comprehensive Behavioral Analysis of Calcium/Calmodulin-Dependent Protein Kinase IV Knockout Mice

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    Calcium-calmodulin dependent protein kinase IV (CaMKIV) is a protein kinase that activates the transcription factor CREB, the cyclic AMP-response element binding protein. CREB is a key transcription factor in synaptic plasticity and memory consolidation. To elucidate the behavioral effects of CaMKIV deficiency, we subjected CaMKIV knockout (CaMKIV KO) mice to a battery of behavioral tests. CaMKIV KO had no significant effects on locomotor activity, motor coordination, social interaction, pain sensitivity, prepulse inhibition, attention, or depression-like behavior. Consistent with previous reports, CaMKIV KO mice exhibited impaired retention in a fear conditioning test 28 days after training. In contrast, however, CaMKIV KO mice did not show any testing performance deficits in passive avoidance, one of the most commonly used fear memory paradigms, 28 days after training, suggesting that remote fear memory is intact. CaMKIV KO mice exhibited intact spatial reference memory learning in the Barnes circular maze, and normal spatial working memory in an eight-arm radial maze. CaMKIV KO mice also showed mildly decreased anxiety-like behavior, suggesting that CaMKIV is involved in regulating emotional behavior. These findings indicate that CaMKIV might not be essential for fear memory or spatial memory, although it is possible that the activities of other neural mechanisms or signaling pathways compensate for the CaMKIV deficiency

    Purpose, use, and preparation of clinical practice guidelines for the management of biliary tract and ampullary carcinomas

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    Apart from periampullary carcinoma, the prognosis of biliary tract carcinomas, including hilar cholangiocarcinoma, extrahepatic biliary tract carcinoma, and gallbladder carcinoma, remains poor. Sophisticated diagnostic skills and treatment methods and their application are naturally required to achieve better treatment results for biliary tract carcinomas. However, it is not too much to say that, due to the paucity of high-level evidence for the management of these carcinomas, medical care by healthcare providers in clinics and at medical institutes throughout the world is currently delivered without common consensus and common standards. The clinical practice guidelines for the management of biliary carcinoma outlined here were produced with the aim that they could be used by physicians involved in the care of biliary tract carcinomas, as indicators that could help them provide their patients with the most appropriate care possible at this time. Also, the guidelines were prepared to provide measures that could assure patients with biliary tract carcinomas of safe medical care. The present guidelines are characterized by their clarification of clinical questions assumed to be often shared by healthcare professionals. For clarity, we divided the contents of the guidelines into eight areas. In each area, clinical questions are presented, together with recommendations of clinical actions in response to the question. As mentioned already, there is a paucity of high-level evidence in this area; therefore, the recommendations are classified into grades, of which there are five: A, strongly recommend performing the clinical action; B, recommend performing the clinical action; C1, the clinical action may be useful, although there is a lack of high-level scientific evidence; C2, clinical action not definitively recommended ecause of insufficient scientific evidence; D, recommend not performing the clinical action. The grading of the recommendations is based on the determination of the level of evidence in references on which the recommendation is based
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