540 research outputs found
194Idiotype vaccination following high dose chemotherapy + autologous stem cell transplant in indolent and mantle cell lymphoma
Planetary detection limits taking into account stellar noise. I. Observational strategies to reduce stellar oscillation and granulation effects
The radial velocity signature of stellar noise is small, around the
meter-per-second, but already too much for the detection of Earth mass planets
in habitable zones. In this paper, we address the important role played by
observational strategies in averaging out the radial velocity signature of
stellar noise. We also derive the planetary mass detection limits expected in
presence of stellar noise. We start with HARPS asteroseismology measurements
for 4 stars (beta Hyi, alpha Cen A, mu Ara and tau Ceti) available in the ESO
archive plus very precise measurements of alpha Cen B. This sample covers
different spectral types, from G2 to K1 and different evolutionary stage, from
subgiant to dwarf stars. Since the span of our data ranges between 5 to 8 days,
we will have access to oscillation modes and granulation phenomena, without
important contribution of activity noise which is present at larger time
scales. For those 5 stars, we generate synthetic radial velocity measurements
after fitting corresponding models of stellar noise in Fourier space. These
measurements allows us to study the radial velocity variation due to stellar
noise for different observational strategies as well as the corresponding
planetary mass detection limits. Applying 3 measurements per night of 10
minutes exposure each, 2 hours apart, seems to average out most efficiently the
stellar noise considered. For quiet K1V stars as alpha Cen B, such a strategy
allows us to detect planets of ~3 times the mass of Earth with an orbital
period of 200 days, corresponding to the habitable zone of the star. Since
activity is not yet included in our simulation, these detection limits
correspond to a case, which exist, where the host star has few magnetic
features. In this case stellar noise is dominated by oscillation modes and
granulation phenomena.Comment: 12 pages, 6 figures, Accepted for publication in A&
A direct numerical simulation method for complex modulus of particle dispersions
We report an extension of the smoothed profile method (SPM)[Y. Nakayama, K.
Kim, and R. Yamamoto, Eur. Phys. J. E {\bf 26}, 361(2008)], a direct numerical
simulation method for calculating the complex modulus of the dispersion of
particles, in which we introduce a temporally oscillatory external force into
the system. The validity of the method was examined by evaluating the storage
and loss moduli of a system composed of identical
spherical particles dispersed in an incompressible Newtonian host fluid at
volume fractions of , 0.41, and 0.51. The moduli were evaluated at
several frequencies of shear flow; the shear flow used here has a zigzag
profile, as is consistent with the usual periodic boundary conditions
Genome wide analysis of gene expression changes in skin from patients with type 2 diabetes
Non-healing chronic ulcers are a serious complication of diabetes and are a major healthcare problem. While a host of treatments have been explored to heal or prevent these ulcers from forming, these treatments have not been found to be consistently effective in clinical trials. An understanding of the changes in gene expression in the skin of diabetic patients may provide insight into the processes and mechanisms that precede the formation of non-healing ulcers. In this study, we investigated genome wide changes in gene expression in skin between patients with type 2 diabetes and non-diabetic patients using next generation sequencing. We compared the gene expression in skin samples taken from 27 patients (13 with type 2 diabetes and 14 non-diabetic). This information may be useful in identifying the causal factors and potential therapeutic targets for the prevention and treatment of diabetic related diseases
Estimating the p-mode frequencies of the solar twin 18 Sco
Solar twins have been a focus of attention for more than a decade, because
their structure is extremely close to that of the Sun. Today, thanks to
high-precision spectrometers, it is possible to use asteroseismology to probe
their interiors. Our goal is to use time series obtained from the HARPS
spectrometer to extract the oscillation frequencies of 18 Sco, the brightest
solar twin. We used the tools of spectral analysis to estimate these
quantities. We estimate 52 frequencies using an MCMC algorithm. After
examination of their probability densities and comparison with results from
direct MAP optimization, we obtain a minimal set of 21 reliable modes. The
identification of each pulsation mode is straightforwardly accomplished by
comparing to the well-established solar pulsation modes. We also derived some
basic seismic indicators using these values. These results offer a good basis
to start a detailed seismic analysis of 18 Sco using stellar models.Comment: 12 pages, 6 figures, to be published in A&
Towards ensemble asteroseismology of the young open clusters Chi Persei and NGC 6910
As a result of the variability survey in Chi Persei and NGC6910, the number
of Beta Cep stars that are members of these two open clusters is increased to
twenty stars, nine in NGC6910 and eleven in Chi Persei. We compare pulsational
properties, in particular the frequency spectra, of Beta Cep stars in both
clusters and explain the differences in terms of the global parameters of the
clusters. We also indicate that the more complicated pattern of the variability
among B type stars in Chi Persei is very likely caused by higher rotational
velocities of stars in this cluster. We conclude that the sample of pulsating
stars in the two open clusters constitutes a very good starting point for the
ensemble asteroseismology of Beta Cep-type stars and maybe also for other
B-type pulsators.Comment: 4 pages, Astronomische Nachrichten, HELAS IV Conference, Arecife,
Lanzarote, Feb 2010, submitte
Advanced Technologies for Oral Controlled Release: Cyclodextrins for oral controlled release
Cyclodextrins (CDs) are used in oral pharmaceutical formulations, by means of inclusion complexes formation, with the following advantages for the drugs: (1) solubility, dissolution rate, stability and bioavailability enhancement; (2) to modify the drug release site and/or time profile; and (3) to reduce or prevent gastrointestinal side effects and unpleasant smell or taste, to prevent drug-drug or drug-additive interactions, or even to convert oil and liquid drugs into microcrystalline or amorphous powders. A more recent trend focuses on the use of CDs as nanocarriers, a strategy that aims to design versatile delivery systems that can encapsulate drugs with better physicochemical properties for oral delivery. Thus, the aim of this work was to review the applications of the CDs and their hydrophilic derivatives on the solubility enhancement of poorly water soluble drugs in order to increase their dissolution rate and get immediate release, as well as their ability to control (to prolong or to delay) the release of drugs from solid dosage forms, either as complexes with the hydrophilic (e.g. as osmotic pumps) and/ or hydrophobic CDs. New controlled delivery systems based on nanotechonology carriers (nanoparticles and conjugates) have also been reviewed
Foot Loading Characteristics of Chinese Bound Feet Women: A Comparative Analysis
The custom of bound feet among Chinese women has existed for almost a century. This practice has influenced the daily life of Chinese women, especially during everyday locomotion. The primary aim of this study is to analyze the loading patterns of bound feet. Specifically, the plantar pressure and center of pressure were analyzed for peak pressure, contact area, force time integral, center of pressure displacement velocity and trajectory in the anterior- posterior direction via a comparison with normal feet. The key outcomes from this work were that the forefoot and rearfoot of bound feet bear the whole loading during stance phase. The center of pressure displacement velocity of bound feet was also greatly reduced with the shortening of trajectories. This suggests that the proprioceptive system adjusts motor function to adapt to new loading patterns while maintaining locomotive stability. A biomechanical understanding of bound feet may assist with prevention, treatment and rehabilitation of bound feet disorders
Transposable Elements Are a Major Cause of Somatic Polymorphism in Vitis vinifera L.
Through multiple vegetative propagation cycles, clones accumulate mutations in somatic cells that are at the origin of clonal phenotypic diversity in grape. Clonal diversity provided clones such as Cabernet-Sauvignon N°470, Chardonnay N° 548 and Pinot noir N° 777 which all produce wines of superior quality. The economic impact of clonal selection is therefore very high: since approx. 95% of the grapevines produced in French nurseries originate from the French clonal selection. In this study we provide the first broad description of polymorphism in different clones of a single grapevine cultivar, Pinot noir, in the context of vegetative propagation. Genome sequencing was performed using 454 GS-FLX methodology without a priori, in order to identify and quantify for the first time molecular polymorphisms responsible for clonal variability in grapevine. New generation sequencing (NGS) was used to compare a large portion of the genome of three Pinot noir clones selected for their phenotypic differences. Reads obtained with NGS and the sequence of Pinot noir ENTAV-INRA® 115 sequenced by Velasco et al., were aligned on the PN40024 reference sequence. We then searched for molecular polymorphism between clones. Three types of polymorphism (SNPs, Indels, mobile elements) were found but insertion polymorphism generated by mobile elements of many families displayed the highest mutational event with respect to clonal variation. Mobile elements inducing insertion polymorphism in the genome of Pinot noir were identified and classified and a list is presented in this study as potential markers for the study of clonal variation. Among these, the dynamic of four mobile elements with a high polymorphism level were analyzed and insertion polymorphism was confirmed in all the Pinot clones registered in France
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