16 research outputs found
En praktisk formidlingsudfordring – om formidling af sproglige emner på sprogportalen sproget.dk
Dansk Sprognævn og Det Danske Sprog- og Litteraturselskab arbejder i øjeblikketpå at etablere en internetportal om det danske sprog. I artiklen beskrives portalensformål, målgrupper og indhold. Desuden skit seres portalens overordnede struktur,der gives et eksempel på hvordan en bruger kan anvende portalen, og de kommendeopgaver frem til lanceringen i september 2007 ridses op
The divide–expand–consolidate MP2 scheme goes massively parallel
For large molecular systems conventional implementations of second order Møller–Plesset (MP2) theory encounter a scaling wall, both memory- and time-wise. We describe how this scaling wall can be removed. We present a massively parallel algorithm for calculating MP2 energies and densities using the divide–expand–consolidate scheme where a calculation on a large system is divided into many small fragment calculations employing local orbital spaces. The resulting algorithm is linear-scaling with system size, exhibits near perfect parallel scalability, removes memory bottlenecks and does not involve any I/O. The algorithm employs three levels of parallelisation combined via a dynamic job distribution scheme. Results on two molecular systems containing 528 and 1056 atoms (4278 and 8556 basis functions) using 47,120 and 94,240 cores are presented. The results demonstrate the scalability of the algorithm both with respect to the number of cores and with respect to system size. The presented algorithm is thus highly suited for large super computer architectures and allows MP2 calculations on large molecular systems to be carried out within a few hours – for example, the correlated calculation on the molecular system containing 1056 atoms took 2.37 hours using 94240 cores.Web of Science1119-111210119
Echocardiographic predictors of exercise capacity and mortality in chronic obstructive pulmonary disease
BACKGROUND: Chronic obstructive pulmonary disease (COPD) reduces exercise capacity, but lung function parameters do not fully explain functional class and lung-heart interaction could be the explanation. We evaluated echocardiographic predictors of mortality and six minutes walking distance (6MWD), a marker for quality of life and mortality in COPD. METHODS: Ninety COPD patients (GOLD criteria) were evaluated by body plethysmography, 6MWD and advanced echocardiography parameters (pulsed wave tissue Doppler and speckle tracking). RESULTS: Mean 6MWD was 403 (± 113) meters. All 90 subjects had preserved left ventricular (LV) ejection fraction 64.3% ± 8.6%. Stroke volume decreased while heart rate increased with COPD severity and hyperinflation. In 66% of patients, some degree of diastolic dysfunction was present. Mitral tissue Doppler data in COPD could be interpreted as a sign of low LV preload and not necessarily an intrinsic impairment in LV relaxation/compliance. Tricuspid regurgitation (TR) increased with COPD severity and hyperinflation. Age (p < 0.001), BMI (p < 0.001), DLCO SB (p < 0.001) and TR (p 0.005) were independent predictors of 6MWD and a multivariable model incorporating heart function parameters (adjusted r(2) = .511) compared well to a model with lung function parameters alone (adjusted r(2) = .475). LV global longitudinal strain (p = 0.034) was the only independent predictor of mortality among all baseline, body plethysmographic and echocardiographic variables. CONCLUSIONS: Among subjects with moderate to severe COPD and normal LVEF, GLS independently predicted all-cause mortality. Exercise tolerance correlated with standard lung function parameters only in univariate models; in subsequent models including echocardiographic parameters, longer 6MWD correlated independently with milder TR, better DLCO SB, younger age and lower BMI. We extended the evidence on COPD affecting cardiac chamber volumes, LV preload, heart rate, as well as systolic and diastolic function. Our results highlight lung-heart interaction and the necessity of cardiac evaluation in COPD