Optical application and measurement of torque on microparticles of isotropic nonabsorbing material

We show how it is possible to controllably rotate or align microscopic particles of isotropic nonabsorbing material in a TEM00 Gaussian beam trap, with simultaneous measurement of the applied torque using purely optical means. This is a simple and general method of rotation, requiring only that the particle is elongated along one direction. Thus, this method can be used to rotate or align a wide range of naturally occurring particles. The ability to measure the applied torque enables the use of this method as a quantitative tool--the rotational equivalent of optical tweezers based force measurement. As well as being of particular value for the rotation of biological specimens, this method is also suitable for the development of optically-driven micromachines.Comment: 8 pages, 6 figure

Supporting knowledge transfer in web-based managed IT support

Purpose &ndash; The purpose of this paper is to highlight the importance and complexities of the knowledge transfer process in the provision of effective managed after-sales IT support, when the web is used for service delivery.Design/methodology/approach &ndash; The paper features an interpretive case study of a multinational Managed Service Provider (MSP) and a focus group of representatives from five comparable MSPs.Findings &ndash; The paper finds that MSPs that use web-based channels for the provision of after-sales IT support services need to address a range of important social and organisational issues in order to realise cost and efficiency-based benefits.Research limitations/implications &ndash; The paper provides a four stage processual model of knowledge transfer in the provision of web-based managed after-sales IT support services. The barriers and enablers of knowledge transfer at each stage are identified. The paper adopts a MSP perspective and suggests that further research from the customer perspective is required.Practical implications &ndash; The paper highlights some important social and organisational enablers and barriers, which will guide MSPs when providing managed after-sales IT support using webbased channels.Originality/value &ndash; The paper provides the first staged model of inter-organisational knowledge transfer in a complex multi-organisational and multi-channel web-based context.<br /

Electromyographic assessment of muscle fatigue in massive rotator cuff tear

Shoulder muscle fatigue has not been assessed in massive rotator cuff tear (MRCT). This study used EMG to measure fatigability of 13 shoulder muscles in 14 healthy controls and 11 patients with MRCT. A hand grip protocol was applied to minimise artifacts due to pain experience during measurement. The fatigue index (median frequency slope) was significantly non-zero (negative) for anterior, middle, and posterior parts of deltoid, supraspinatus and subscapularis muscles in the controls, and for anterior, middle, and posterior parts of deltoid, and pectoralis major in patients (p ≤ 0.001). Fatigue was significantly greater in patients compared to the controls for anterior and middle parts of deltoid and pectoralis major (p ≤ 0.001). A submaximal grip task provided a feasible way to assess shoulder muscle fatigue in MRCT patients, however with some limitations. The results suggest increased activation of deltoid is required to compensate for lost supraspinatus abduction torque. Increased pectoralis major fatigue in patients (adduction torque) likely reflected strategy to stabilise the humeral head against superior subluxing force of the deltoid. Considering physiotherapy as a primary or adjunct intervention for the management of MRCT, the findings of this study generate a base for future clinical studies aiming at the development of evidence-based protocol

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele