Search results for " statistical"
showing 10 items of 1649 documents
Clinical value of increased serum creatinine concentration as predictor of short-term outcome in decompensated cirrhosis
2004
The purpose of this study was to assess whether serum creatinine concentration alone or associated with other biological parameters was an independent predictor of short-term mortality in patients with decompensated cirrhosis.A total of 212 consecutive episodes of decompensated cirrhosis in patients admitted to the hospital between January 1999 and December 2001 were reviewed retrospectively. Depending on a serum creatinine concentration equal to or greater than 1.5 mg/dL at the time of admission, patients were divided into decompensated cirrhosis with renal failure (101 episodes in 59 patients, aged 69.8 +/- 10 years) and without renal failure (111 episodes in 61 patients, aged 64.5 +/- 13…
Guide to Practical Work with the Monte Carlo Method
2002
The guide is structured such that we proceed from the “easy” simulation methods and algorithms to the more sophisticated. For each method the algorithms are presented by the technique of stepwise refinement. We first present the idea and the basic outline. From then on we proceed by breaking up the larger logical and algorithmic structures into smaller ones, until we have reached the level of single basic statements. Sometimes we may elect not to go to such a depth and the reader is asked to fill in the gaps.
Mixed complexes of alkaline earth uranyl cabonates: A laser-induced time-resolved fluorescence spectroscopic study
2008
The interaction of the alkaline earth ions Mg2+, Sr2+ and Ba2+ with the uranyl tricarbonate complex has been studied by time resolved laser-induced fluorescence spectroscopy. In contrast to the non-luminescent uranyl tricarbonate complex the formed products show slight luminescence properties. These have been used to determine the stoichiometry and complex stabilities of the formed compounds. As the alkaline earth elements are located in an outer shell of the complex the influence of the type of the alkaline earth element on the stability constant is not very drastic. Therefore all obtained data were averaged in order to derive an common stability constant for the described complexes. These…
Langevin Approach to Levy Flights in Fixed Potentials: Exact Results for Stationary Probability Distributions
2008
The functional method to derive the fractional Fokker-Planck equation for probability distribution from the Langevin equation with Levy stable noise is proposed. For the Cauchy stable noise we obtain the exact stationary probability density function of Levy flights in different smooth potential profiles. We find confinement of the particle in the superdiffusion motion with a bimodal stationary distribution for all the anharmonic symmetric monostable potentials investigated. The stationary probability density functions show power-law tails, which ensure finiteness of the variance. By reviewing recent results on these statistical characteristics, the peculiarities of Levy flights in compariso…
Dioxin emissions and soft-tissue sarcoma: results of a population-based case-control study.
2004
International audience; BACKGROUND: In 1998, the French Ministry of Environment revealed that of 71 French municipal solid waste incinerators processing more than 6 metric tons of material per hour, dioxin emission from 15 of them was above the 10 ng international toxic equivalency factor/m3 (including Besançon, emitting 16.3 ng international toxic equivalency factor/m3) which is substantially higher than the 0.1 international toxic equivalency factor/m3 prescribed by a European directive of 1994. In 2000, a macrospatial epidemiological study undertaken in the administrative district of Doubs, identified two significant clusters of soft-tissue sarcoma and non Hodgkin lymphoma in the vicinit…
The EORTC computer-adaptive tests measuring physical functioning and fatigue exhibited high levels of measurement precision and efficiency
2013
Objectives: The European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group is developing a computer-adaptive test (CAT) version of the EORTC Quality of Life Questionnaire (QLQ-C30). We evaluated the measurement properties of the CAT versions of physical functioning (PF) and fatigue (FA) and compared these with the corresponding QLQ-C30 scales. Study Design and Setting: Based on international samples of more than 1,000 cancer patients, we simulated CAT administration of varying numbers of items and compared the resulting scores with those based on all items in the respective item pools. Furthermore, the relative validity (RV) of CATs was compared with that of th…
Coupled stochastic dynamics of magnetic moment and anisotropy axis of a magnetic nanoparticle
2012
An algorithm is developed for numerical simulation of coupled stochastic dynamics of magnetic moment and magnetic anisotropy axis of a nanoparticle. Time-correlation functions of the magnetic moment and its components longitudinal and transverse to the magnetic anisotropy axis are calculated by averaging along the stochastic trajectory. The longitudinal and transverse relaxation times are found by fitting the time correlation functions. Existing theoretical relations derived by the effective field approach in the limit of small fields are confirmed. The time-correlation functions of magnetic moments of nanoparticles in dependence on their properties are calculated numerically for arbitrary …
Fungal-Mediated Multitrophic Interactions : Do Grass Endophytes in Diet Protect Voles from Predators?
2009
Plant-associated micro-organisms such as mycotoxin-producing endophytes commonly have direct negative effects on herbivores. These effects may be carried over to natural enemies of the herbivores, but this has been rarely explored. We examined how feeding on Neotyphodium endophyte infected (E+) and endophyte free (E−) meadow ryegrass (Scherodonus pratensis) affects body mass, population size and mobility of sibling voles (Microtus levis), and whether the diet mediates the vulnerability of voles to least weasel (Mustela nivalis nivalis) predation. Because least weasels are known to be olfactory hunters, we also examined whether they are able to distinguish olfactory cues of voles fed on E+ a…
Comparison of Different Hypotheses Regarding the Spread of Alzheimer’s Disease Using Markov Random Fields and Multimodal Imaging
2018
Alzheimer’s disease (AD) is characterized by a cascade of pathological processes that can be assessed in vivo using different neuroimaging methods. Recent research suggests a systematic sequence of pathogenic events on a global biomarker level, but little is known about the associations and dependencies of distinct lesion patterns on a regional level. Markov random fields are a probabilistic graphical modeling approach that represent the interaction between individual random variables by an undirected graph. We propose the novel application of this approach to study the interregional associations and dependencies between multimodal imaging markers of AD pathology and to compare different hy…
Circulating monocyte subsets and heart failure prognosis
2018
Altres ajuts: Fundacio' La MARATO' de TV3 (201502 to ABG, 201516), AdvanceCat with the support of ACCIÓ [Catalonia Trade & Investment, Generalitat de Catalunya], Fundació Bancària La Caixa. Monocytes are a heterogeneous population of effector cells with key roles in tissue integrity restoration and maintenance. Here, we explore the association of monocyte subsets and prognosis in patients with ambulatory heart failure (HF). Monocyte subsets were classified as classical (CD14 ++ /CD16 -), intermediate (CD14 ++ /CD16 +), or non-classical (CD14 + /CD16 ++). Percentage distribution and absolute cell count were assessed in each subset, and multivariable Cox regression analyses were performed wit…