Search results for "quantitative"
showing 10 items of 2409 documents
Characterization of component pigments in a mixture
2011
This work is part of Raman spectra database constitution of pigments and materials of Cultural Heritage interest for polychrome artworks characterization. The colours of paintings are often obtained mixing pigments of palette artist’s. The attribution of a work of art to an author and the individuation of fakes are related to the identification of used pigments and also to the detection of mixture constituents. The main research objective is the extension of PH3DRA laboratory database with information useful to detect not only each single pigment but also quantitative data regarding its relative ratio in the examined mixture. The availability of spectra as revealed represents the primary li…
Interactions, spillovers de connaissance et croissance des économies modernes. Faut-il préférer la globalisation ou la proximité géographique ?
2009
Globalisation and metropolisation in modern economies induce some locational strategies of knowledge based activities towards cities and deeply increase trade and move of ideas across cities. In that context, we study the way knowledge spillovers have influenced the economic growth of 82 European Metropolises over the 1990-2005 period. We model knowledge spillovers across cities according to three specific interaction patterns depending either on geography or on global advanced services or thought a combination of these patterns. We show that the mixed pattern matters the best for economic growth of cities in Europe.
L'eldorado Bitcoin
2018
Conçu par ses inventeurs comme le fondement d'un nouvel ordre monétaire, le Bitcoin semble avoir été rattrapé par la finance et devenir l'occasion de spéculations juteuses. Presque 10 ans après le lancement du Bitcoin, Bercy souhaiterait, avec l'aide de l'Autorité des Marchés Financiers et d'une réglementation souple et incitative, faire de Paris la place financière la plus attractive pour les ICO (Initial Coin Offering), ces levées de fonds en cryptomonnaies qui ont connu une progression record au premier trimestre de l'année 2018. Début janvier, d'autres pays tels la Chine ou la Corée du Sud durcissaient leurs positions face à ce nouvel écosystème, tandis que des projets de monnaies digit…
Application of Molecular Topology for the Prediction of Reaction Yields and Anti-Inflammatory Activity of Heterocyclic Amidine Derivatives
2011
Topological-mathematical models based on multiple linear regression analyses have been built to predict the reaction yields and the anti-inflammatory activity of a set of heterocylic amidine derivatives, synthesized under environmental friendly conditions, using microwave irradiation. Two models with three variables each were selected. The models were validated by cross-validation and randomization tests. The final outcome demonstrates a good agreement between the predicted and experimental results, confirming the robustness of the method. These models also enabled the screening of virtual libraries for new amidine derivatives predicted to show higher values of reaction yields and anti-infl…
The assessment of skeletal status in young patients with Turner syndrome by 2 densitometric techniques: Phalangeal quantitative ultrasound and dual e…
2018
Background. Studies using dual energy X-ray absorptiometry (DXA) demonstrate a reduction in bone mineral density (BMD) in children and adolescents with Turner syndrome (TS). However, these studies do not take into account changes in bone size, which influence BMD in the case of short-statured patients. Phalangeal quantitative ultrasound (phQUS) measurements have shown an ability to reveal changes due to skeletal growth, aging, and bone and mineral disorders. There is limited data on bone mineral status in girls with TS assessed by 2 different techniques, i.e., DXA and phQUS. Objectives. The aim of this study was to investigate the potential negative impact of TS on bone status and to assess…
Monitoring bone growth using quantitative ultrasound in comparison with DXA and pQCT.
2008
Quantitative ultrasound (QUS) is a safe, inexpensive, and nonradiation method for bone density assessment. QUS correlates with, and predicts fragility fractures comparable to, dual-energy X-ray absorptiometry (DXA)-derived bone mineral density (BMD) in postmenopausal women. However, its validity in monitoring bone growth in children is not well understood. Two hundred and fifty-eight 10-13 yr pubertal girls and 9 37-43 yr adults without diseases or history of medications known to affect bone metabolism were included in the 2-yr prospective study. Calcaneal broadband ultrasound attenuation (cBUA) was assessed using QUS-2 (Quidel, Santa Clara, CA), speed of sound of tibial shaft (tSOS) using …
Both Resistance and Agility Training Increase Cortical Bone Density in 75- to 85-Year-Old Women With Low Bone Mass
2004
A randomized, controlled, single-blinded 25-wk prospective study was conducted to compare the effects of group-based resistance and agility training on bone, as measured by both dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT), in older women with low bone mass. Ninety-eight community-dwelling women aged 75-85 yr were randomized to one of three experimental groups: resistance training (n = 32), agility training (n = 34), or stretching (sham exercise) (n = 32). Total hip, femoral neck, and trochanteric bone mineral density (BMD) were measured by DXA. Peripheral QCT measurements were performed at the tibia and radius. The pQCT outcome measures at t…
Bone and cartilage characteristics in postmenopausal women with mild knee radiographic osteoarthritis and those without radiographic osteoarthritis
2015
Objectives: To evaluate the association between radiographically-assessed knee osteoarthritis and femoral neck bone characteristics in women with mild knee radiographic osteoarthritis and those without radiographic osteoarthritis. Methods: Ninety postmenopausal women (mean age [SD], 58 [4] years; height, 163 [6] cm; weight, 71 [11] kg) participated in this cross-sectional study. The severity of radiographic knee osteoarthritis was defined using Kellgren-Lawrence grades 0=normal (n=12), 1=doubtful (n=25) or 2=minimal (n=53). Femoral neck bone mineral content (BMC), section modulus (Z), and cross-sectional area (CSA) were measured with DXA. The biochemical composition of ipsilateral knee cart…
Vergleich radiologischer Verfahren zur präoperativen Beurteilung der Verankerungsfestigkeit von Wirbelsäulenimplantaten
1997
PURPOSE To compare three techniques with regards to their ability to estimate pull out strength of spinal fusion hardware. MATERIAL AND METHODS VDS-screw fixation strength in 50 human cadaveric vertebral bodies was approximated by means of pull out force measurement. Bone quality was assessed by Dual X-ray Absorptiometry (DXA). Quantitative Computed Tomography (QCT) and T2*-relaxation time. For each of these techniques, correlation with axial pull out force strength was investigated. RESULTS Highest correlation was found for cancellous bone density measured by QCT (r = 0.72; p < 0.001). Immediately followed by DXA (r = 0.70; p < 0.001), which involves all bone components. Inverted T2*-relax…
Quasi-Fractional Models of Human Tendons Hereditariness
2018
In this study, the authors, after collecting a series of experimental evidences following a creep and relaxation tendon campaign, propose a non-linear model of the viscoelastic behavior of the tendons. The ligaments investigated are the patellars and the hamstrings. The analytical model proposed by the authors aims to explain the non-linear hereditary behavior of these tissues and proposes an approach with which to develop a hereditary fractional-order non-linear model.