Search results for "Reference"
showing 10 items of 2491 documents
Vitamin D and immunomodulation: Is it time to change the reference values?
2017
The term "vitamin D" refers to two chemical compounds - ergosterol, or vitamin D2, and cholecalciferol, or vitamin D3. Active vitamin D3 is correctly regarded as a neurohormone due to its pleiotropic biological activities. Although the relation between vitamin D and calcium-phosphorus metabolism has never been discussed, the knowledge on many other roles vitamin D plays is growing fast. Briefly, vitamin D immunomodulation includes attenuation and stimulation of Th1 and Th2 cell proliferation, respectively. Similarly, vitamin D can induce or inhibit the synthesis, secretion, and release of anti- inflammatory (IL- 4 and IL-10) and pro-inflammatory (IL-1, TNF-α, IFN-γ) cytokines, respectivel…
Dissemination of Spanish Social Sciences and Humanities Journals
2005
The presence of scholarly journals in international data bases promotes the dissemination of research results and also facilitates requests for specific articles or journals by end users. As scientists seek optimal visibility for their work and wish their results to be published in journals with high circulation, it is important to know which are the leading journals within each scientific area. This paper contains a bibliometric study of scientific journals in the areas of Social Sciences and Humanities that are currently published in Spain, together with information concerning their production and circulation in the different national and international bibliographical data bases, publishe…
Employee types and endogenous organizational design: an experiment
2011
When managers are sufficiently guided by social preferences, incentive provision through an organizational mode based on informal implicit contracts may provide a cost-effective alternative to a more formal mode based on explicit contracts and active monitoring. This paper reports the results from a stylized laboratory experiment designed to test whether subjects in the role of firm owner rely on the social preferences of other (‘employee’) subjects with whom they are matched when choosing which payoff version of a simple trust game these employee subjects should play (‘the organizational mode’). Our main finding is that they do so, albeit in a different way than theory predicts. The import…
MPI-DING reference glasses for in situ microanalysis: New reference values for element concentrations and isotope ratios
2006
We present new analytical data of major and trace elements for the geological MPI-DING glasses KL2-G, ML3B-G, StHs6/80-G, GOR128-G, GOR132-G, BM90/21-G, T1-G, and ATHO-G. Different analytical methods were used to obtain a large spectrum of major and trace element data, in particular, EPMA, SIMS, LA-ICPMS, and isotope dilution by TIMS and ICPMS. Altogether, more than 60 qualified geochemical laboratories worldwide contributed to the analyses, allowing us to present new reference and information values and their uncertainties (at 95% confidence level) for up to 74 elements. We complied with the recommendations for the certification of geological reference materials by the International Associ…
NanoSr - A New Carbonate Microanalytical Reference Material for In Situ Strontium Isotope Analysis
2019
The in situ measurement of Sr isotopes in carbonates by MC‐ICP‐MS is limited by the availability of suitable microanalytical reference materials (RMs), which match the samples of interest. Whereas several well‐characterised carbonate reference materials for Sr mass fractions > 1000 µg g−1 are available, there is a lack of well‐characterised carbonate microanalytical RMs with lower Sr mass fractions. Here, we present a new synthetic carbonate nanopowder RM with a Sr mass fraction of ca. 500 µg g−1 suitable for microanalytical Sr isotope research (‘NanoSr’). NanoSr was analysed by both solution‐based and in situ techniques. Element mass fractions were determined using EPMA (Ca mass fraction),…
Getting new bronchodilator compounds from molecular topology.
2003
Abstract Molecular topology has been used to select new lead bronchodilator compounds. The main advantage of this method, as compared to others frequently used, is that it does not require a previous explicit knowledge of the mechanism of action (MOA) of the compounds analyzed. A large database (12,000 chemicals) has been examined in this study to find less than 5% compounds with bronchodilator activity. After removing those compounds already described as bronchodilators, we present here the results for 20 among these compounds, some of them showing other pharmacological activities. Some of the compounds selected in this study showed higher relaxation and higher potency than theophylline, w…
Equilibrium geometries of cyclic SiC3 isomers
2001
Equilibrium geometries of two isomers of cyclic SiC3 are determined by both large scale ab initio calculation and a procedure involving the use of experimental data from microwave spectroscopy and calculated harmonic and cubic force fields. Internuclear distances corresponding to structures obtained by both procedures agree to better than 0.003 A in all cases, allowing for precise recommendations of equilibrium structures. Rather large residual inertial defects obtained from moments of inertia based on rotational constants adjusted for effects of vibration–rotation interaction were found to be reduced significantly by inclusion of electronic contributions as estimated from calculations of r…
Locating Objects Away from Earth Surface: Positioning Accuracy
2013
The motion of the Galileo and GPS satellite constellations is simulated in Schwarzschild space-time, whereas photons travel in Minkowski space-time. This is a good enough approach to deal with the main goal of this paper: the study of positioning accuracy in the framework of the so-called relativistic positioning. Our study is based on numerical 4D simulations. In this meeting, the contribution of J.A. Morales-Lladosa contains some basic ideas which have been important to perform our numerical calculations. For four chosen emitters (satellites) of a certain constellation, many receivers located at different distances from Earth surface and in distinct directions are considered. Thus, we ver…
A particle swarm approach for tuning washout algorithms in vehicle simulators
2018
Abstract The MCA tuning problem involves finding the most appropriate values for the parameters (or coefficients) of Motion Cueing Algorithms (MCA), also known as washout algorithms. These algorithms are designed to control the movements of the robotic mechanisms, referred to as motion platforms, employed to generate inertial cues in vehicle simulators. This problem can be approached in several different ways. The traditional approach is to perform a manual pilot-in-the-loop subjective tuning, using the opinion of several pilots/drivers to guide the process. A more systematic approach is to use optimization techniques to explore the vast parameter space of the MCA, using objective motion fi…
Long time behavior for a dissipative shallow water model
2013
We consider the two-dimensional shallow water model derived by Levermore and Sammartino (Nonlinearity 14,2001), describing the motion of an incompressible fluid, confined in a shallow basin, with varying bottom topography. We construct the approximate inertial manifolds for the associated dynamical system and estimate its order. Finally, considering the whole domain R^2 and under suitable conditions on the time dependent forcing term, we prove the L^2 asymptotic decay of the weak solutions.