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Full-Text Articles in Social and Behavioral Sciences

Improvements In Dose Calculation Accuracy For Small Off-Axis Targets In High Dose Per Fraction Tomotherapy, Nicholas Hardcastle, Adam Bayliss, Jeannie Wong, Anatoly B. Rosenfeld, Wolfgang A. Tome Jun 2013

Improvements In Dose Calculation Accuracy For Small Off-Axis Targets In High Dose Per Fraction Tomotherapy, Nicholas Hardcastle, Adam Bayliss, Jeannie Wong, Anatoly B. Rosenfeld, Wolfgang A. Tome

Anatoly Rozenfeld

Purpose: A recent field safety notice from TomoTherapy detailed the underdosing of small, off-axis targets when receiving high doses per fraction. This is due to angular undersampling in the dose calculation gantry angles. This study evaluates a correction method to reduce the underdosing, to be implemented in the current version (v4.1) of the TomoTherapy treatment planning software. Methods: The correction method, termed "Super Sampling" involved the tripling of the number of gantry angles from which the dose is calculated during optimization and dose calculation. Radiochromic film was used to measure the dose to small targets at various off-axis distances receiving …


Therapeutic Targets In Extracellular Protein Deposition Diseases, Amy R. Wyatt, Justin J. Yerbury, Stephen Poon, Mark R. Wilson May 2013

Therapeutic Targets In Extracellular Protein Deposition Diseases, Amy R. Wyatt, Justin J. Yerbury, Stephen Poon, Mark R. Wilson

Mark R Wilson

Many litres of fluids are found outside cells in the human body. These fluids are rich in dissolved proteins that each have a characteristic three dimensional shape, necessary for normal function, which has been attained by the correct folding of their polypeptide chain(s). The structure of these extracellular proteins can be damaged by a variety of environmental stresses (e. g. heat and oxidation) leading to their partial unfolding and aggregation. This in turn can produce toxic soluble aggregates and/or large insoluble protein deposits, either of which can disrupt normal body function (e. g. in Alzheimer's disease and the systemic amyloidoses). …


Neuregulin-1 Signalling And Antipsychotic Treatment: Potential Therapeutic Targets In A Schizophrenia Candidate Signalling Pathway, Chao Deng, Bo Pan, Martin Engel, Xu-Feng Huang Apr 2013

Neuregulin-1 Signalling And Antipsychotic Treatment: Potential Therapeutic Targets In A Schizophrenia Candidate Signalling Pathway, Chao Deng, Bo Pan, Martin Engel, Xu-Feng Huang

Xu-Feng Huang

Identifying the signalling pathways underlying the pathophysiology of schizophrenia is an essential step in the rational development of new antipsychotic drugs for this devastating disease. Evidence from genetic, transgenic and post-mortem studies have strongly supported neuregulin-1 (NRG1)-ErbB4 signalling as a schizophrenia susceptibility pathway. NRG1-ErbB4 signalling plays crucial roles in regulating neurodevelopment and neurotransmission, with implications for the pathophysiology of schizophrenia. Post-mortem studies have demonstrated altered NRG1-ErbB4 signalling in the brain of schizophrenia patients. Antipsychotic drugs have different effects on NRG1-ErbB4 signalling depending on treatment duration. Abnormal behaviours relevant to certain features of schizophrenia are displayed in NRG1/ErbB4 knockout mice or …


Muscle Synergies Of Feed-Forward Postural Adjustments During Reaching To Multi-Directional Targets In Standing, J Leonard, S Chvatal, L Ting, P Stapley Jan 2013

Muscle Synergies Of Feed-Forward Postural Adjustments During Reaching To Multi-Directional Targets In Standing, J Leonard, S Chvatal, L Ting, P Stapley

Dr Paul J Stapley

Standing balance can be controlled using feedback (FB) or feedforward (FF) mechanisms, depending on the nature of a postural disturbance. Unexpected disturbances of balance elicit automatic postural responses (APR) to restore body position (Horak and Macpherson 1996). Studies of APR have shown that the CNS recruits a small number of muscle synergies to simplify complex task-level goals (e.g. CoM stabilization) to produce the appropriate muscle activation patterns (Ting & McKay, 2007). Successful execution of goal-directed voluntary movements while standing requires FF programming of postural adjustments that serve to initiate movement of the body towards the target (preparatory postural adjustment, pPA) …


Reaching To Multiple Targets When Standing: The Spatial Organization Of Feedforward Postural Adjustments, Julia Leonard, Ryan Brown, Paul Stapley Jan 2013

Reaching To Multiple Targets When Standing: The Spatial Organization Of Feedforward Postural Adjustments, Julia Leonard, Ryan Brown, Paul Stapley

Dr Paul J Stapley

We examined the spatial organization of feedforward postural adjustments produced prior to and during voluntary arm reaching movements executed while standing. We sought to investigate whether the activity of postural muscles before and during reaching was directionally tuned and whether a strategy of horizontal force constraint could be observed. To this end, eight human subjects executed self-paced reach-to-point movements on the random illumination of one of 13 light targets placed within a 180° array centered along the midline of the body. Analysis was divided into two periods: a first corresponding to the 250 ms preceding the onset of the reaching …


Speed Has An Effect On Multiple-Object Tracking Independently Of The Number Of Close Encounters Between Targets And Distractors, Cary S. Feria Jan 2013

Speed Has An Effect On Multiple-Object Tracking Independently Of The Number Of Close Encounters Between Targets And Distractors, Cary S. Feria

Cary S. Feria

Multiple-object tracking (MOT) studies have shown that tracking ability declines as object speed increases. However, this might be attributed solely to the increased number of times that target and distractor objects usually pass close to each other (“close encounters”) when speed is increased, resulting in more target–distractor confusions. The present study investigates whether speed itself affects MOT ability by using displays in which the number of close encounters is held constant across speeds. Observers viewed several pairs of disks, and each pair rotated about the pair’s midpoint and, also, about the center of the display at varying speeds. Results showed …