23 research outputs found
Positive and negative well-being and objectively measured sedentary behaviour in older adults: evidence from three cohorts
Background:
Sedentary behaviour is related to poorer health independently of time spent in moderate to vigorous physical activity. The aim of this study was to investigate whether wellbeing or symptoms of anxiety or depression predict sedentary behaviour in older adults.
Method:
Participants were drawn from the Lothian Birth Cohort 1936 (LBC1936) (n = 271), and the West of Scotland Twenty-07 1950s (n = 309) and 1930s (n = 118) cohorts. Sedentary outcomes, sedentary time, and number of sit-to-stand transitions, were measured with a three-dimensional accelerometer (activPAL activity monitor) worn for 7 days. In the Twenty-07 cohorts, symptoms of anxiety and depression were assessed in 2008 and sedentary outcomes were assessed ~ 8 years later in 2015 and 2016. In the LBC1936 cohort, wellbeing and symptoms of anxiety and depression were assessed concurrently with sedentary behaviour in 2015 and 2016. We tested for an association between wellbeing, anxiety or depression and the sedentary outcomes using multivariate regression analysis.
Results:
We observed no association between wellbeing or symptoms of anxiety and the sedentary outcomes. Symptoms of depression were positively associated with sedentary time in the LBC1936 and Twenty-07 1950s cohort, and negatively associated with number of sit-to-stand transitions in the LBC1936. Meta-analytic estimates of the association between depressive symptoms and sedentary time or number of sit-to-stand transitions, adjusted for age, sex, BMI, long-standing illness, and education, were β = 0.11 (95% CI = 0.03, 0.18) and β = − 0.11 (95% CI = − 0.19, −0.03) respectively.
Conclusion:
Our findings indicate that depressive symptoms are positively associated with sedentary behavior. Future studies should investigate the causal direction of this association
TOMOGRAPHIC FINDINGS OF GASTRIC GASTROINTESTINAL STROMAL TUMOR AND CORRELATION WITH THE MITOTIC INDEX
Comparison of conventional and asymmetric aircraft configurations using CEASIOM
This paper investigates whether drag reductions in cruise can be achieved for an aircraft by selecting a three-lifting-surface asymmetric design. A conventional T-tail design based on the existing EA500 Very Light Jet was selected as the baseline aircraft, and this was redesigned into a novel asymmetric configuration. CEASIOM, the Computerized Environment for Aircraft Synthesis and Integrated Optimization Methods, was then used to generate aerodynamic data sets for both aircraft, trim them at the cruise condition, and compare the thrust required to achieve trim
Creating aero-databases by adaptive-fidelity CFD coupled with S&C analysis to predict flying qualities
CEASIOM, the Computerized Environment for Aircraft Synthesis and Integrated Optimization Methods, is a framework tool that integrates discipline-specific tools for conceptual design. At this early stage of the design it is very useful to be able to predict the flying and handling qualities of this design. In order to do this, the aerodynamic database needs to be computed for the configuration being studied which then has to be coupled to the stability and control tools to carry out the analysis. This paper describes how the adaptive-fidelity CFD module of CEASIOM computes the aerodynamic dataset of an aircraft configuration, and how that dataset is analyzed by the SDSA module to determine the flying qualities of the aircraft. These predicted flying qualities are then compared with the flight-test data of the Ranger 2000 trainer aircraft in order to verify the goodness of the overall approach. The design, simulate and evaluate (DSE) exercise demonstrates how the software works as a design tool. The exercise begins with a design specification and uses conventional design methods to prescribe a baseline configuration. Then CEASIOM improves upon this baseline by analyzing its flying and handling qualities. This paper reports on the DSE case Transonic cruiser TCR from baseline design to Tier-I+ design
Gastrointestinal stromal tumour: spiral computed tomography features and pathologic correlation
PURPOSE: Our purpose was to define the diagnostic accuracy of helical computed tomography (CT) in the identification, characterisation and evaluation of extension of gastrointestinal stromal tumours (GIST) through correlation with some pathological findings.
MATERIALS AND METHODS: Between August 2000 and September 2004, we conducted a retrospective study of the abdominal CT of 15 patients with histological diagnosis of GIST - that is, the immunopositivity for c-kit (CD117) - on a surgical specimen of the primary disease. We used a helical CT single-slice (Toshiba, Asteion; rotation time 0.75 s) in ten cases and helical CT multislice (Toshiba, Aquilion; 4 slices/rotation; rotation time 0.5 s) in five cases. In all cases, we used an organ-iodate nonionic contrast agent intravenously at a concentration of 350-400 mgI/ml. All cases studied the entire abdomen. Site, morphology and tumour size (smaller than 5 cm, 5-10 cm and larger than 10 cm) were considered parameters for tumour identification. Size, partial or total extraluminal tumour growth, homogeneous or inhomogeneous lesion enhancement and the eventual presence of calcifications were assumed to be criteria for characterisation of a GIST. Hepatic, peritoneal and/or lymph node metastases were considered parameters of intermediate or high malignancy. We correlated the results with some pathological features derived from the analysis of surgical tissue: site, morphology and tumour size, tissue components and risk of malignancy of GIST (on the basis of the 2002 Fletcher classification).
RESULTS: We demonstrated one substantial concordance between radiological and pathological valuation of site, morphology, tumour size and absence of intralesional calcifications of GIST. Nine of ten GIST smaller than 5 cm, the two 5-10 cm and the three larger than 10 cm presented extraluminal growth. Enhancement was inhomogeneous in five of ten lesions smaller than 5 cm and in all cases larger than 5 cm. At pathological analysis, in all cases of inhomogeneous enhancement, solid, hemorrhagic, necrotic and cystic areas were found. Of seven tumours of intermediate malignancy, six were smaller than 5 cm and only one larger than 10 cm; the two 5-10 cm were of high malignancy and all tumours superior of 10 cm were at intermediate or high malignancy. Of the two cases with metastases, one was of intermediate and one of high malignancy. In the other cases of intermediate or high malignancy, metastases were absent.
CONCLUSIONS: The immunopositivity for c-kit is requisite for definitive diagnosis of GIST, but imaging, and particularly helical CT, has a primary role. In this study, CT is was reliable for tumour identification. All tumours larger than 5 cm presented extraluminal growth, inhomogeneous enhancement, absence of calcifications and lymph node metastases. Furthermore, the tumour larger than 5 cm showed extraluminal growth and inhomogeneous enhancement. Tumour size established with CT was not sufficient to determine the degree of malignancy. Metastases at the time of diagnosis were indicative of intermediate or high malignancy, but the absence of metastases did not allow classification of GIST in the group of low and very low risk of malignancy
A framework for constrained control allocation using CFD based tabular data
This paper describes a framework for control allocation problem using Computational Fluid Dynamics (CFD) aerodata, which is represented by a multidimensional array of dimensionless coefficients of aerodynamic forces and moments, stored as a function of the state vector and control-surface deflections. The challenges addressed are, first, the control surface treatment for the automated generation of aerodata using CFD and, second, sampling and data fusion to allow the timely calculation of large data tables. In this framework, the generation of aerodynamic tables is described based on an efficient sampling/data fusion approach. Also, the treatment of aerodynamics of control surfaces is being addressed for three flow solvers: TORNADO, a vortex-lattice method, and two CFD codes, EDGE from the Swedis Defence Agency and PMB from the University of Liverpool. In TORNADO, the vortex points located at the trailing edge of the flaps are rotated around the hinge line to simulate the deflected surfaces. The transpiration boundary conditions approach is used for modeling moving flaps in EDGE, whereas, the surface deflection is achieved using mode shapes in PMB. The test cases used to illustrate the approaches is the Ranger 2000 fighter trainer and a reduced geometry description of Boeing 747-100. Data tables are then generated for the state vector and multiple control surface deflections. The look-up table aerodata are then used to resolve the control allocation problem under the constraint that each surface has an upper and lower limit of deflection angle