Effects of Pacing When Using Material Handling Manipulators

Common manipulator-assisted materials handling tasks were performed in a laboratory simulation at self-selected and faster (paced) speeds. The effects of pacing on peak hand forces, torso kinematics, spine moments and forces, and muscle antagonism were determined, along with any influences of several task variables on these effects. The faster trials were performed 20% more rapidly than the self-paced trials. It was found that (a) achieving this level of performance required 10% higher hand forces and 5%-10% higher torso moments, (b) consistent torso postures and motions were used for both speed conditions, and (c) the faster trials resulted in 10% higher spine forces and 15% higher levels of lumbar muscle antagonism. On whole, these results suggest a higher risk of musculoskeletal injury associated with performance of object transfers at faster than self-selected speeds with and without a manipulator. Further analysis provided evidence that the use of manipulators involves higher levels of motor coordination than do manual tasks. Several implications regarding the use of material handling manipulators in paced operations are discussed. Results from this investigation can be used in the design, evaluation, and selection of material handling manipulators.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67067/2/10.1518_001872099779591240.pd

The Bivariate Normal Copula

We collect well known and less known facts about the bivariate normal distribution and translate them into copula language. In addition, we prove a very general formula for the bivariate normal copula, we compute Gini's gamma, and we provide improved bounds and approximations on the diagonal.Comment: 24 page

Von Hippel-Lindau protein in the RPE is essential for normal ocular growth and vascular development

Molecular oxygen is essential for the development, growth and survival of multicellular organisms. Hypoxic microenvironments and oxygen gradients are generated physiologically during embryogenesis and organogenesis. In the eye, oxygen plays a crucial role in both physiological vascular development and common blinding diseases. The retinal pigment epithelium (RPE) is a monolayer of cells essential for normal ocular development and in the mature retina provides support for overlying photoreceptors and their vascular supply. Hypoxia at the level of the RPE is closely implicated in pathogenesis of age-related macular degeneration. Adaptive tissue responses to hypoxia are orchestrated by sophisticated oxygen sensing mechanisms. In particular, the von Hippel-Lindau tumour suppressor protein (pVhl) controls hypoxia-inducible transcription factor (HIF)-mediated adaptation. However, the role of Vhl/Hif1a in the RPE in the development of the eye and its vasculature is unknown. In this study we explored the function of Vhl and Hif1a in the developing RPE using a tissue-specific conditional-knockout approach. We found that deletion of Vhl in the RPE results in RPE apoptosis, aniridia and microphthalmia. Increased levels of Hif1a, Hif2a, Epo and Vegf are associated with a highly disorganised retinal vasculature, chorioretinal anastomoses and the persistence of embryonic vascular structures into adulthood. Additional inactivation of Hif1a in the RPE rescues the RPE morphology, aniridia, microphthalmia and anterior vasoproliferation, but does not rescue retinal vasoproliferation. These data demonstrate that Vhl-dependent regulation of Hif1a in the RPE is essential for normal RPE and iris development, ocular growth and vascular development in the anterior chamber, whereas Vhl-dependent regulation of other downstream pathways is crucial for normal development and maintenance of the retinal vasculature

Evaluation of a risk-stratification strategy to improve primary care for low back pain: the MATCH cluster randomised trial protocol

Background Despite numerous options for treating back pain and the increasing healthcare resources devoted to this problem, the prevalence and impact of back pain-related disability has not improved. It is now recognized that psychosocial factors, as well as physical factors, are important predictors of poor outcomes for back pain. A promising new approach that matches treatments to the physical and psychosocial obstacles to recovery, the STarT Back risk stratification approach, improved patients’ physical function while reducing costs of care in the United Kingdom (UK). This trial evaluates implementation of this strategy in a United States (US) healthcare setting. Methods Six large primary care clinics in an integrated healthcare system in Washington State were block-randomized, three to receive an intensive quality improvement intervention for back pain and three to serve as controls for secular trends. The intervention included 6 one-hour training sessions for physicians, 5 days of training for physical therapists, individualized and group coaching of clinicians, and integration of the STarT Back tool into the electronic health record. This prognostic tool uses 9 questions to categorize patients at low, medium or high risk of persistent disabling pain with recommendations about evidence-based treatment options appropriate for each subgroup. Patients at least 18 years of age, receiving primary care for non-specific low back pain, were invited to provide data 1–3 weeks after their primary care visit and follow-up data 2 months and 6 months (primary endpoint) later. The primary outcomes are back-related physical function and pain severity. Using an intention to treat approach, intervention effects on patient outcomes will be estimated by comparing mean changes at the 2 and 6 month follow-up between the pre- and post-implementation periods. The inclusion of control clinics permits adjustment for secular trends. Differences in change scores by intervention group and time period will be estimated using linear mixed models with random effects. Secondary outcomes include healthcare utilization and adherence to clinical guidelines. Discussion This trial will provide the first randomized trial evidence of the clinical effectiveness of implementing risk stratification with matched treatment options for low back pain in a United States health care delivery system

DISTRIBUTION AND PROPERTIES OF CDP-DIGLYCERIDE:INOSITOL TRANSFERASE FROM BRAIN 1

CDP-diglyceride is converted to phosphatidyl inositol by several particulate subcellular fractions of guinea pig brain, with highest specific activity in the microsomal fraction. Optimal conditions with respect to pH, metal ion concentration, and substrate concentrations have been determined. The reaction was stimulated by the addition of bovine serum albumin and by Tween 80. Of several dl-CDP-diglycerides synthesized and used as substrates in a spectrophoto-metric assay for the enzyme, dl-CDP-didecanoin was the most active. The enzyme showed a high selectivity for myo-inositol. Of a number of compounds tested, only scyllo -inosose and epi -inosose served as substrates. Three inositol isomers and three myo -inositol monophosphates inhibited the reaction slightly. The most potent inhibitor found was galactinol, a myo -inositol galactoside.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66197/1/j.1471-4159.1969.tb06850.x.pd

Engagement of Fusiform Cortex and Disengagement of Lateral Occipital Cortex in the Acquisition of Radiological Expertise

The human visual pathways that are specialized for object recognition stretch from lateral occipital cortex (LO) to the ventral surface of the temporal lobe, including the fusiform gyrus. Plasticity in these pathways supports the acquisition of visual expertise, but precisely how training affects the different regions remains unclear. We used functional magnetic resonance imaging to measure neural activity in both LO and the fusiform gyrus in radiologists as they detected abnormalities in chest radiographs. Activity in the right fusiform face area (FFA) correlated with visual expertise, measured as behavioral performance during scanning. In contrast, activity in left LO correlated negatively with expertise, and the amount of LO that responded to radiographs was smaller in experts than in novices. Activity in the FFA and LO correlated negatively in experts, whereas in novices, the 2 regions showed no stable relationship. Together, these results suggest that the FFA becomes more engaged and left LO less engaged in interpreting radiographic images over the course of training. Achieving expert visual performance may involve suppressing existing neural representations while simultaneously developing others

Rationale, design and methods of the Study of Work and Pain (SWAP): a cluster randomised controlled trial testing the addition of a vocational advice service to best current primary care for patients with musculoskeletal pain (ISRCTN 52269669)

Background Musculoskeletal pain is a major contributor to short and long term work absence. Patients seek care from their general practitioner (GP) and yet GPs often feel ill-equipped to deal with work issues. Providing a vocational case management service in primary care, to support patients with musculoskeletal problems to remain at or return to work, is one potential solution but requires robust evaluation to test clinical and cost-effectiveness. Methods/Design This protocol describes a cluster randomised controlled trial, with linked qualitative interviews, to investigate the effect of introducing a vocational advice service into general practice, to provide a structured approach to managing work related issues in primary care patients with musculoskeletal pain who are absent from work or struggling to remain in work. General practices (n = 6) will be randomised to offer best current care or best current care plus a vocational advice service. Adults of working age who are absent from or struggling to remain in work due to a musculoskeletal pain problem will be invited to participate and 330 participants will be recruited. Data collection will be through patient completed questionnaires at baseline, 4 and 12 months. The primary outcome is self-reported work absence at 4 months. Incremental cost-utility analysis will be undertaken to calculate the cost per additional QALY gained and incremental net benefits. A linked interview study will explore the experiences of the vocational advice service from the perspectives of GPs, nurse practitioners (NPs), patients and vocational advisors. Discussion This paper presents the rationale, design, and methods of the Study of Work And Pain (SWAP) trial. The results of this trial will provide evidence to inform primary care practice and guide the development of services to provide support for musculoskeletal pain patients with work-related issues. Trial registration Current Controlled Trials ISRCTN52269669