548 research outputs found

    Connectivity as the capacity to improve an organization’s decision-making

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    This paper describes the development of a new computational model to predict the desirability of decision consequences in an organization, and the development of a prototype tool to enable real-time interaction and decision support when changes occur simultaneously. A tool, called Decision Propagation System, is developed in response to the needs of BT Group plc in understanding the most effective set of interventions in the organization where the high degree of connectivity between system components and the uncertainty in connectivity data are two critical issues. Designed on a case study of the Fields Operations Engineering, this research demonstrates that a knowledge of overlapping decision propagation paths can direct the organizational decisions towards mitigating the risk of unintended consequences

    Inductively-overcoupled coil design for high resolution magnetic resonance imaging

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    BACKGROUND: Maintaining the quality of magnetic resonance images acquired with the current implantable coil technology is challenging in longitudinal studies. To overcome this challenge, the principle of 'inductive overcoupling' is introduced as a method to tune and match a dual coil system. This system consists of an imaging coil built with fixed electrical elements and a matching coil equipped with tuning and matching capabilities. Overcoupling here refers to the condition beyond which the peak of the current in the imaging coil splits. METHODS: The combined coils are coupled inductively to operate like a transformer. Each coil circuit is electrically represented by equivalent lumped-elements. A theoretical analysis is given to identify the frequency response characteristics of the currents in each coil. The predictions from this analysis are translated into experiments and applied to locally image rat spinal cord at 9.4 T using an implantable coil as the imaging coil and an external volume coil as the matching coil. RESULTS: The theoretical analysis indicated that strong coupling between the coils divides the resonance peaks on the response curves of the currents. Once these newly generated peaks were tuned and matched to the desired frequency and impedance of operation, in vivo images were acquired from the rat spinal cord at high quality and high resolution. CONCLUSION: After proper implementation, inductive overcoupling provides a unique opportunity for tuning and matching the coil system, and allows reliable and repeatable acquisitions of magnetic resonance data. This feature is likely to be useful in experimental studies, such as those aimed at longitudinally imaging the rat following spinal cord injury

    Microstructural damage of the posterior corpus callosum contributes to the clinical severity of neglect

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    One theory to account for neglect symptoms in patients with right focal damage invokes a release of inhibition of the right parietal cortex over the left parieto-frontal circuits, by disconnection mechanism. This theory is supported by transcranial magnetic stimulation studies showing the existence of asymmetric inhibitory interactions between the left and right posterior parietal cortex, with a right hemispheric advantage. These inhibitory mechanisms are mediated by direct transcallosal projections located in the posterior portions of the corpus callosum. The current study, using diffusion imaging and tract-based spatial statistics (TBSS), aims at assessing, in a data-driven fashion, the contribution of structural disconnection between hemispheres in determining the presence and severity of neglect. Eleven patients with right acute stroke and 11 healthy matched controls underwent MRI at 3T, including diffusion imaging, and T1-weighted volumes. TBSS was modified to account for the presence of the lesion and used to assess the presence and extension of changes in diffusion indices of microscopic white matter integrity in the left hemisphere of patients compared to controls, and to investigate, by correlation analysis, whether this damage might account for the presence and severity of patients' neglect, as assessed by the Behavioural Inattention Test (BIT). None of the patients had any macroscopic abnormality in the left hemisphere; however, 3 cases were discarded due to image artefacts in the MRI data. Conversely, TBSS analysis revealed widespread changes in diffusion indices in most of their left hemisphere tracts, with a predominant involvement of the corpus callosum and its projections on the parietal white matter. A region of association between patients' scores at BIT and brain FA values was found in the posterior part of the corpus callosum. This study strongly supports the hypothesis of a major role of structural disconnection between the right and left parietal cortex in determining 'neglect'

    Number and cost of claims linked to minor cervical trauma in Europe: results from the comparative study by CEA, AREDOC and CEREDOC

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    Comparative epidemiological study of minor cervical spine trauma (frequently referred to as whiplash injury) based on data from the Comité Européen des Assurances (CEA) gathered in ten European countries. To determine the incidence and expenditure (e.g., for assessment, treatment or claims) for minor cervical spine injury in the participating countries. Controversy still surrounds the basis on which symptoms following minor cervical spine trauma may develop. In particular, there is considerable disagreement with regard to a possible contribution of psychosocial factors in determining outcome. The role of compensation is also a source of constant debate. The method followed here is the comparison of the data from different areas of interest (e.g., incidence of minor cervical spine trauma, percentage of minor cervical spine trauma in relationship to the incidence of bodily trauma, costs for assessment or claims) from ten European countries. Considerable differences exist regarding the incidence of minor cervical spine trauma and related costs in participating countries. France and Finland have the lowest and Great Britain the highest incidence of minor cervical spine trauma. The number of claims following minor cervical spine trauma in Switzerland is around the European average; however, Switzerland has the highest expenditure per claim at an average cost of €35,000.00 compared to the European average of €9,000.00. Furthermore, the mandatory accident insurance statistics in Switzerland show very large differences between German-speaking and French- or Italian-speaking parts of the country. In the latter the costs for minor cervical spine trauma expanded more than doubled in the period from 1990 to 2002, whereas in the German-speaking part they rose by a factor of five. All the countries participating in the study have a high standard of medical care. The differences in claims frequency and costs must therefore reflect a social phenomenon based on the different cultural attitudes and medical approach to the problem including diagnosis. In Switzerland, therefore, new ways must be found to try to resolve the problem. The claims treatment model known as “Case Management” represents a new approach in which accelerated social and professional reintegration of the injured party is attempted. The CEA study emphasizes the fundamental role of medicine in that it postulates a clear division between the role of the attending physician and the medical expert. It also draws attention to the need to train medical professionals in the insurance business to the extent that they can interact adequately with insurance professionals. The results of this study indicate that the usefulness of the criterion of so-called typical clinical symptoms, which is at present applied by the courts to determine natural causality and has long been under debate, is inappropriate and should be replaced by objective assessment (e.g. accident and biomechanical analysis). In addition, the legal concept of adequate causality should be interpreted in the same way in both third party liability and social security law, which is currently not the case

    Effects of isoflavones (soy phyto-estrogens) on serum lipids: a meta-analysis of randomized controlled trials

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    OBJECTIVES: To determine the effects of isoflavones (soy phyto-estrogens) on serum total cholesterol (TC), low density lipoprotein cholesterol (LDL), high density lipoprotein cholesterol (HDL) and triglyceride (TG). METHODS: We searched electronic databases and included randomized trials with isoflavones interventions in the forms of tablets, isolated soy protein or soy diets. Review Manager 4.2 was used to calculate the pooled risk differences with fixed effects model. RESULTS: Seventeen studies (21 comparisons) with 853 subjects were included in this meta-analysis. Isoflavones tablets had insignificant effects on serum TC, 0.01 mmol/L (95% CI: -0.17 to 0.18, heterogeneity p = 1.0); LDL, 0.00 mmol/L (95% CI: -0.14 to 0.15, heterogeneity p = 0.9); HDL, 0.01 mmol/L (95% CI: -0.05 to 0.06, heterogeneity p = 1.0); and triglyceride, 0.03 mmol/L (95% CI: -0.06 to 0.12, heterogeneity p = 0.9). Isoflavones interventions in the forms of isolated soy protein (ISP), soy diets or soy protein capsule were heterogeneous to combine. CONCLUSIONS: Isoflavones tablets, isolated or mixtures with up to 150 mg per day, seemed to have no overall statistical and clinical benefits on serum lipids. Isoflavones interventions in the forms of soy proteins may need further investigations to resolve whether synergistic effects are necessary with other soy components

    Hemolytic uremic syndrome following the infusion of oxaliplatin: case report

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    BACKGROUND: Oxaliplatin is a platinum derivative, which is used in the treatment of colorectal cancer. A small number of oxaliplatin-related hemolytic and/or thrombocytopenic reactions have been reported. We present a case of hemolytic-uremic syndrome that developed during the 4(th )cycle of combination chemotherapy with oxaliplatin, 5-fluorouracil and leucovorin. CASE PRESENTATION: A 52-year-old-male was administered chemotherapy with oxaliplatin, 5-fluorouracil and leucovorin for a Duke's stage C colorectal carcinoma. Three cycles of chemotherapy had been administered without complications when, at the beginning of the fourth cycle, the patient developed clinical and laboratory abnormalities consistent with the development of the hemolytic-uremic syndrome. Treatment was discontinued; the patient was managed with monitored IV hydration and loop diuretics, high dose corticosteroids and fresh frozen plasma infusions and recovered completely. CONCLUSION: The hemolytic-uremic syndrome may be a rare complication of oxaliplatin-based chemotherapy. Clinicians need to maintain a high index of suspicion to diagnose and treat this life-threatening adverse event

    Incidence and risk factors for important early morbidities associated with pediatric cardiac surgery in a UK population

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    Objective Given excellent 30-day survival for pediatric cardiac surgery, other outcome measures are important. We aimed to study important early postoperative morbidities selected by stakeholders following a rigorous and evidenced-based process, with a view to identifying potential risk factors. Methods The incidence of selected morbidities was prospectively measured for 3090 consecutive pediatric cardiac surgical admissions in 5 UK centers between October 2015 and June 2017. The relationship between the candidate risk factors and the incidence of morbidities was explored using multiple regressions. Patient survival, a secondary outcome, was checked at 6 months. Results A total of 675 (21.8%) procedure episodes led to at least 1 of the following: acute neurologic event, unplanned reoperation, feeding problems, renal replacement therapy, major adverse events, extracorporeal life support, necrotizing enterocolitis, surgical infection, or prolonged pleural effusion. The highest adjusted odds ratio of morbidity was in neonates compared with children, 5.26 (95% confidence interval, 3.90-7.06), and complex heart diseases (eg, hypoplastic left heart), 2.14 (95% confidence interval, 1.41-3.24) compared with low complexity (eg, atrial septal defect, P < .001 for all). Patients with any selected morbidity had a 6-month survival of 88.2% (95% confidence interval, 85.4-90.6) compared with 99.3% (95% confidence interval, 98.9-99.6) with no defined morbidity (P < .001). Conclusions Evaluation of postoperative morbidity provides important information over and above 30-day survival and should become a focus for audit and quality improvement. Our results have been used to initiate UK-based audit for 5 of these 9 morbidities, co-develop software for local monitoring of these morbidities, and parent information about these morbidities

    Post-depositional fracturing and subsidence of pumice flow deposits: Lascar Volcano, Chile

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    Unconsolidated pyroclastic flow deposits of the 1993 eruption of Lascar Volcano, Chile, have, with time, become increasingly dissected by a network of deeply penetrating fractures. The fracture network comprises orthogonal sets of decimeter-wide linear voids that form a pseudo-polygonal grid visible on the deposit surface. In this work, we combine shallow surface geophysical imaging tools with remote sensing observations and direct field measurements of the deposit to investigate these fractures and their underlying causal mechanisms. Based on ground penetrating radar images, the fractures are observed to have propagated to depths of up to 10 m. In addition, orbiting radar interferometry shows that deposit subsidence of up to 1 cm/year occurred between 1993 and 1996 with continued subsidence occurring at a slower rate thereafter. In situ measurements show that 1 m below the surface, the 1993 deposits remain 5°C to 15°C hotter, 18 years after emplacement, than adjacent deposits. Based on the observed subsidence as well as estimated cooling rates, the fractures are inferred to be the combined result of deaeration, thermal contraction, and sedimentary compaction in the months to years following deposition. Significant environmental factors, including regional earthquakes in 1995 and 2007, accelerated settling at punctuated moments in time. The spatially variable fracture pattern relates to surface slope and lithofacies variations as well as substrate lithology. Similar fractures have been reported in other ignimbrites but are generally exposed only in cross section and are often attributed to formation by external forces. Here we suggest that such interpretations should be invoked with caution, and deformation including post-emplacement subsidence and fracturing of loosely packed ash-rich deposits in the months to years postemplacement is a process inherent in the settling of pyroclastic material
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