title: The effect of proprioceptive knee bracing on knee stability after anterior cruciate ligament reconstruction

authors: Hanzlíková, Ivana

subjects: Kinematic

abstract: Background Injury to the anterior cruciate ligament (ACL) is common among young athletes and can impact knee stability and control. Wearing proprioceptive knee braces can improve knee control and may reduce the risk factors associated with injury and re-injury, although the effect of such braces after ACL reconstruction (ACLR) is unclear. Research question This study aimed to determine the effect of proprioceptive knee bracing on knee control and subjective rating of participants post ACLR during three dynamic tasks. Methods Fifteen participants 2–10 years post ACLR performed a slow step down, single leg drop jump, and pivot turn jump with and without a proprioceptive knee brace. Knee kinematics in the sagittal (flexion – extension), coronal (abduction – adduction), and transverse (internal – external rotation) planes were collected using a 3D infrared system. Paired t-tests were performed to explore differences in knee angles and angular velocities between the no brace and brace conditions during the three tasks. After each task, subjective ratings regarding ease of the task were recorded. Results The brace reduced the peak knee external rotation angle and range of motion in the transverse plane during the pivot turn jump task, and significantly increased the maximum knee flexion angular velocity during the single leg drop jump task. The majority of participants reported that tasks were easier to perform with the proprioceptive brace than without. Significance This study confirms that proprioceptive knee braces can significantly influence knee kinematics during dynamic tasks post ACLR. The observed effects were clinically relevant.

text: The effect of proprioceptive knee bracing on knee stability after anterior cruciate ligament reconstruction Background Injury to the anterior cruciate ligament (ACL) is common among young athletes and can impact knee stability and control. Wearing proprioceptive knee braces can improve knee control and may reduce the risk factors associated with injury and re-injury, although the effect of such braces after ACL reconstruction (ACLR) is unclear. Research question This study aimed to determine the effect of proprioceptive knee bracing on knee control and subjective rating of participants post ACLR during three dynamic tasks. Methods Fifteen participants 2–10 years post ACLR performed a slow step down, single leg drop jump, and pivot turn jump with and without a proprioceptive knee brace. Knee kinematics in the sagittal (flexion – extension), coronal (abduction – adduction), and transverse (internal – external rotation) planes were collected using a 3D infrared system. Paired t-tests were performed to explore differences in knee angles and angular velocities between the no brace and brace conditions during the three tasks. After each task, subjective ratings regarding ease of the task were recorded. Results The brace reduced the peak knee external rotation angle and range of motion in the transverse plane during the pivot turn jump task, and significantly increased the maximum knee flexion angular velocity during the single leg drop jump task. The majority of participants reported that tasks were easier to perform with the proprioceptive brace than without. Significance This study confirms that proprioceptive knee braces can significantly influence knee kinematics during dynamic tasks post ACLR. The observed effects were clinically relevant.

year: 2019

title: On the insecurity of arithmetic coding

authors: Cleary, John G.

subjects: computer science

abstract: Arithmetic coding is a technique which converts a given probability distribution into an optimal code and is commonly used in compression schemes. The use of arithmetic coding as an encryption scheme is considered. The simple case of a single binary probability distribution with a fixed (but unknown) probability is considered. We show that for a chosen plaintext attack w+ 2 characters is sufficient to uniquely determine a w-bit probability. For many known plaintexts w+ m+ O(log m) symbols where mis the length of an initial sequence containing just one of (the two possible) symbols is sufficient. It is noted that many extensions to this basic scheme are vulnerable to the same attack provided the arithmetic coder can be repeatedly reset to its initial state. If it cannot be reset then their vulnerability remains an open question.

text: On the insecurity of arithmetic coding Arithmetic coding is a technique which converts a given probability distribution into an optimal code and is commonly used in compression schemes. The use of arithmetic coding as an encryption scheme is considered. The simple case of a single binary probability distribution with a fixed (but unknown) probability is considered. We show that for a chosen plaintext attack w+ 2 characters is sufficient to uniquely determine a w-bit probability. For many known plaintexts w+ m+ O(log m) symbols where mis the length of an initial sequence containing just one of (the two possible) symbols is sufficient. It is noted that many extensions to this basic scheme are vulnerable to the same attack provided the arithmetic coder can be repeatedly reset to its initial state. If it cannot be reset then their vulnerability remains an open question.

year: 1994-06

title: Kaupapa Māori framework and literature review of key prinicples

authors: Kennedy, Nathan

subjects: New Zealand

abstract: The literature review in this report was the starting point for the development of a Māori research strand within the Planning Under Co-operative Mandates (PUCM) research programme. The original purpose of this report Kaupapa Māori Framework and Literature Review of Key Principles was to establish definitions of environmentally significant concepts of kaupapa and tikanga Māori. In  addition,  the  review  sought  to  identify  and  briefly  describe  significant  variations between  understandings of the key concepts without attempting to reconcile these. As the purpose of the review in 2005 was to inform the development of a kaupapa Māori methodology for the identification and development of Māori environmental outcomes and indicators, we paid particular regard to Māori perceptions of the environment and the relevance of each concept in environmental terms.

text: Kaupapa Māori framework and literature review of key prinicples The literature review in this report was the starting point for the development of a Māori research strand within the Planning Under Co-operative Mandates (PUCM) research programme. The original purpose of this report Kaupapa Māori Framework and Literature Review of Key Principles was to establish definitions of environmentally significant concepts of kaupapa and tikanga Māori. In  addition,  the  review  sought  to  identify  and  briefly  describe  significant  variations between  understandings of the key concepts without attempting to reconcile these. As the purpose of the review in 2005 was to inform the development of a kaupapa Māori methodology for the identification and development of Māori environmental outcomes and indicators, we paid particular regard to Māori perceptions of the environment and the relevance of each concept in environmental terms.

year: 2009-06-30