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Automatic Assessment of Expanded Disability Status Scale (EDSS) in Multiple Sclerosis Using a Decision Tree  [PDF]
Hua Cao, Olivier Agnani, Laurent Peyrodie, Cécile Donzé
Engineering (ENG) , 2013, DOI: 10.4236/eng.2013.510B116
Abstract:

The expanded disability status scale (EDSS) is frequently used to classify the patients with multiple sclerosis (MS). We presented in this paper a novel method to automatically assess the EDSS score from posturologic data (center of pres-sure signals) using a decision tree. Two groups of participants (one for learning and the other for test) with EDSS rang-ing from 0 to 4.5 performed our balance experiment with eyes closed. Two linear measures (the length and the surface) and twelve non-linear measures (the recurrence rate, the Shannon entropy, the averaged diagonal line length and the trapping time for the position, the instantaneous velocity and the instantaneous acceleration of the center of pressure respectively) were calculated for all the participants. Several decision trees were constructed with learning data and tested with test data. By comparing clinical and estimated EDSS scores in the test group, we selected one decision tree with five measures which revealed a 75% of agreement. The results have signified that our tree model is able to auto-matically assess the EDSS scores and that it is possible to distinguish the EDSS scores by using linear and non-linear postural sway measures.


Computer Solution to the Game of Pure Strategy
Glenn C. Rhoads,Laurent Bartholdi
Games , 2012, DOI: 10.3390/g3040150
Abstract: We numerically solve the classical "Game of Pure Strategy" using linear programming. We notice an intricate even-odd behaviour in the results of our computations that seems to encourage odd or maximal bids.
Local Helioseismology
Gizon Laurent,Birch Aaron C.
Living Reviews in Solar Physics , 2005,
Abstract: We review the current status of local helioseismology, covering both theoretical and observational results. After a brief introduction to solar oscillations and wave propagation through inhomogeneous media, we describe the main techniques of local helioseismology: Fourier-Hankel decomposition, ring-diagram analysis, time-distance helioseismology, helioseismic holography, and direct modeling. We discuss local helioseismology of large-scale flows, the solar-cycle dependence of these flows, perturbations associated with regions of magnetic activity, and solar supergranulation.
Helioseismology challenges models of solar convection
Laurent Gizon,Aaron C. Birch
Physics , 2012, DOI: 10.1073/pnas.1208875109
Abstract: Convection is the mechanism by which energy is transported through the outermost 30% of the Sun. Solar turbulent convection is notoriously difficult to model across the entire convection zone where the density spans many orders of magnitude. In this issue of PNAS, Hanasoge et al. (2012) employ recent helioseismic observations to derive stringent empirical constraints on the amplitude of large-scale convective velocities in the solar interior. They report an upper limit that is far smaller than predicted by a popular hydrodynamic numerical simulation.
Testosterone Levels Do Not Decline with Age in Healthy Men  [PDF]
Akanksha Mehta, Alexander Bolyakov, Raymond C. Sultan, Laurent Vaucher, Anna Mielnik, Joseph Kiper, Darius A. Paduch
Open Journal of Urology (OJU) , 2013, DOI: 10.4236/oju.2013.34032
Abstract:

Aim: To establish norms for reproductive hormones in healthy males with normal urologic and sexual function, and to assess the change in reproductive hormone levels with respect to age among healthy males. Methods: Healthy volunteers aged 18 - 29 (group 1) and 45 - 65 (group 2) were recruited for enrollment in a prospective study. Inclusion criteria comprised normal urinary, ejaculatory, orgasmic, and erectile function, as determined by IPSS, MSHQ, and IEFF-15. Men with history of chronic medical illnesses or chronic medication use were excluded. Fifty men met the study criteria. Each participant underwent physical examination and standardized serum hormone evaluation using ELISA and EIA methods. Statistical analysis was performed using JMP 8.0 software (SAS Institute Inc., Cary, NC), to compare hormone levels between the two groups of men. Results: There were 25 men each in groups 1 (mean age 26) and 2 (mean age 51). Overall, 46% were Caucasian, 31% African American, 15% Hispanic, and 8% Asian. There was no statistically significant difference in serum total T, SHBG, E2, or LH between groups 1 and 2. Notably, the 95% CI for serum T levels for both groups of men were considerably higher than commonly accepted lower-end cut-off limits. Conclusion: Serum T levels do not vary significantly with age, in otherwise healthy men with normal sexual and urologic function. Furthermore, healthy men have much higher serum total and free T levels than the lower-end reference limits provided by commercial laboratories.

Fast Fatty Acid Analysis by Core-Shell Reversed-Phase Liquid Chromatography Coupled to Evaporative Light-Scattering Detector  [PDF]
Florence Hubert, Céline Loiseau, Fran?oise Ergan, Ga?lle Pencréac’h, Laurent Poisson
Food and Nutrition Sciences (FNS) , 2017, DOI: 10.4236/fns.2017.812077
Abstract:
A high-performance liquid chromatography analysis method with an evaporative light-scattering detector has been developed for the separation and quantitative analysis of free fatty acids in biological matrices. Core-shell reversed-phase high-performance liquid chromatography separation of 10 free fatty acids is achieved within 10.5 min using a methanol/water (0.05% trifluoroacetic acid) eluent gradient. After optimization, the drift tube and nebulization temperature of the evaporative light-scattering detector was set at 35°C, nitrogen flow-rate at 1.1 standard liter per minute and column temperature at 25°C. All calibration curves showed good regression (r2 > 0.9975). A validation procedure following the International Conference on Harmonisation guidelines was implemented to certify the method. Relative standard deviations did not exceed 1.5% and 4.25% for repeatability and reproducibility respectively.
Tolerance of fungal infection in European water frogs exposed to Batrachochytrium dendrobatidis after experimental reduction of innate immune defenses
Douglas C Woodhams, Laurent Bigler, Rachel Marschang
BMC Veterinary Research , 2012, DOI: 10.1186/1746-6148-8-197
Abstract: Naturally-acquired Bd infections were detected in 10/51 P. lessonae and 4/19 P. esculentus, but no disease outbreaks or population declines have been detected at this site. Thus, this population was immunologically primed, and disease resistant. No mortality occurred during the 64 day experiment. Forty percent of initially uninfected frogs became sub-clinically infected upon experimental exposure to Bd. Reduction of both skin peptide and microbiota immune defenses caused frogs to gain less mass when exposed to Bd than frogs in other treatments. Microbiota-reduced frogs increased peptide production upon Bd infection. Ranavirus was undetectable in all but two frogs that appeared healthy in the field, but died within a week under laboratory conditions. Virus was detectable in both toe-clips and internal organs.Intact skin microbiota reduced immune activation and can minimize subclinical costs of infection. Tolerance of Bd or ranavirus infection may differ with ecological conditions.Experimental studies are needed in disease ecology to determine the relative importance of factors influencing disease outcome. Results can be applied to conservation management of amphibians encountering a variety of infectious diseases emerging with global change [1-5]. Two predominant amphibian pathogens associated with global population declines are ranaviruses and the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd).Ranaviruses are large icosahedral DNA viruses belonging to the family Iridoviridae. They have been detected in fish, amphibians and reptiles. Ranavirus associated disease in amphibians has been reported in the Americas, Europe, and Asia, and ranaviruses have also been detected in amphibians in Australia [4,6]. To our knowledge, there are no previous reports of ranavirus occurring in wild-caught amphibians in Switzerland.Bd is the causal agent of chytridiomycosis, an amphibian disease capable of producing epizootics and perhaps species extinctions [3,7]. The fungu
Turbulence Observations in a Buoyant Hydrothermal Plume on the East Pacific Rise
Andreas M. Thurnherr,Louis C. St. Laurent
Oceanography , 2012,
Abstract: Hot vent fluid enters the ocean at high-temperature hydrothermal vents, also known as black smokers. Because of the large temperature difference between the vent fluid and oceanic near-bottom waters, the hydrothermal effluent initially rises as a buoyant plume through the water column. During its rise, the plume engulfs and mixes with background ocean water. This process, called entrainment, gradually reduces the density of the rising plume until it reaches its level of neutral buoyancy, where the plume density equals that of the background water, and it begins to spread along a surface of constant density. (For a much more detailed discussion of buoyant hydrothermal plumes, see Di Iorio et al., 2012, in this issue.)
Aspergillosis in HIV patients: a case series
F Laurent,C Martin,S De Wit
Journal of the International AIDS Society , 2012, DOI: 10.7448/ias.15.6.18132
Abstract: Purpose: Aspergillosis is uncommon in HIV patients and has been mostly reported in patients with CD4<50/μL. Data on risk factors and prognosis are scarce. We reviewed 19 cases of aspergillosis diagnosed in our HIV cohort. Methods: In the Brussels Saint-Pierre HIV cohort, 19 patients were diagnosed with aspergillosis between 1998 and 2012 (0.87/1000 patient/year of follow-up). We analyzed retrospectively and described localization and invasiveness of aspergillosis, risk factors, treatment and outcome of these patients. Results: Patients were mostly African (74%) and mean age was 40 years (22–60). Clinical presentation were 10 invasive aspergillosis (IA) (53%), 6 pulmonary aspergilloma (31%) and 3 sinus fungal ball (16%). The global mortality was 42%. IA was proven for 3 patients, probable for 4 patients and possible for 3 patients according to IDSA definitions. Risk factors for IA included CD4<200/μL (70%; 40%<50 CD4/μL), corticotherapy (50%), neutropenia (20%), intravenous drug use (20%), cirrhosis (20%). IA arose in the time course of septic shock in 30% and opportunistic infections occurred concomitantly in 40%. Seven patients out of 10 with IA died including 3 patients before antifungal therapy. The 3 survivors recovered without relapse. Four patients were treated with voriconazole, 2 with itraconazole, 2 with liposomal amphotericine, 1 with caspofungine, and 2 with bitherapy. Among patients with aspergilloma (n=6), the major associated risk factor was tuberculosis sequelae (80%). Two patients were successfully treated with surgery and voriconazole, 1 died from massive hemoptysis, 2 were lost to follow-up, 1 is currently asymptomatic without treatment. Among patients with sinus fungal ball (n=3), all recovered without relapse with surgical treatment associated with voriconazole for one. Conclusion: Incidence of aspergillosis in HIV patients remains low but in accordance to previous reports, mortality of IA is high (70%). CD4<200 is the most common risk factor (70%) but 80% of patients who died had other risk factors, mostly corticotherapy. IA is often concomitant with other infectious diseases (40% with other opportunistic infections and 30% in the time course of septic shock), which can potentially delay diagnosis. Prognosis of pulmonary aspergilloma and sinus fungal ball is better.
Assessing the Applicability of the GTR Nucleotide Substitution Model Through Simulations
Laurent Gatto,Daniele Catanzaro,Michel C. Milinkovitch
Evolutionary Bioinformatics , 2006,
Abstract: The General Time Reversible (GTR) model of nucleotide substitution is at the core of many distance-based and character-based phylogeny inference methods. The procedure described by Waddell and Steel (1997), for estimating distances and instantaneous substitution rate matrices, R, under the GTR model, is known to be inapplicable under some conditions, ie, it leads to the inapplicability of the GTR model. Here, we simulate the evolution of DNA sequences along 12 trees characterized by different combinations of tree length, (non-)homogeneity of the substitution rate matrix R, and sequence length. We then evaluate both the frequency of the GTR model inapplicability for estimating distances and the accuracy of inferred alignments. Our results indicate that, inapplicability of the Waddel and Steel’s procedure can be considered a real practical issue, and illustrate that the probability of this inapplicability is a function of substitution rates and sequence length. We also discuss the implications of our results on the current implementations of maximum likelihood and Bayesian methods.
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