4,020 research outputs found
Simulation of Flow of Mixtures Through Anisotropic Porous Media using a Lattice Boltzmann Model
We propose a description for transient penetration simulations of miscible
and immiscible fluid mixtures into anisotropic porous media, using the lattice
Boltzmann (LB) method. Our model incorporates hydrodynamic flow, diffusion,
surface tension, and the possibility for global and local viscosity variations
to consider various types of hardening fluids. The miscible mixture consists of
two fluids, one governed by the hydrodynamic equations and one by diffusion
equations. We validate our model on standard problems like Poiseuille flow, the
collision of a drop with an impermeable, hydrophobic interface and the
deformation of the fluid due to surface tension forces. To demonstrate the
applicability to complex geometries, we simulate the invasion process of
mixtures into wood spruce samples.Comment: Submitted to EPJ
Relationship between intact HIV-1 proviruses in circulating CD4+ T cells and rebound viruses emerging during treatment interruption.
Combination antiretroviral therapy controls but does not cure HIV-1 infection because a small fraction of cells harbor latent viruses that can produce rebound viremia when therapy is interrupted. The circulating latent virus reservoir has been documented by a variety of methods, most prominently by viral outgrowth assays (VOAs) in which CD4+ T cells are activated to produce virus in vitro, or more recently by amplifying proviral near full-length (NFL) sequences from DNA. Analysis of samples obtained in clinical studies in which individuals underwent analytical treatment interruption (ATI), showed little if any overlap between circulating latent viruses obtained from outgrowth cultures and rebound viruses from plasma. To determine whether intact proviruses amplified from DNA are more closely related to rebound viruses than those obtained from VOAs, we assayed 12 individuals who underwent ATI after infusion of a combination of two monoclonal anti-HIV-1 antibodies. A total of 435 intact proviruses obtained by NFL sequencing were compared with 650 latent viruses from VOAs and 246 plasma rebound viruses. Although, intact NFL and outgrowth culture sequences showed similar levels of stability and diversity with 39% overlap, the size of the reservoir estimated from NFL sequencing was larger than and did not correlate with VOAs. Finally, intact proviruses documented by NFL sequencing showed no sequence overlap with rebound viruses; however, they appear to contribute to recombinant viruses found in plasma during rebound
Proof of the Pruning Front Conjecture for certain H\'enon parameters
The Pruning Front Conjecture is proved for an open set of H\'enon parameters
far from unimodal. More specifically, for an open subset of H\'enon parameter
space, consisting of two connected components one of which intersects the
area-preserving locus, it is shown that the associated H\'enon maps are
prunings of the horseshoe. In particular, their dynamics is a subshift of the
two-sided two-shift
Scattering from supramacromolecular structures
We study theoretically the scattering imprint of a number of branched
supramacromolecular architectures, namely, polydisperse stars and dendrimeric,
hyperbranched structures. We show that polydispersity and nature of branching
highly influence the intermediate wavevector region of the scattering structure
factor, thus providing insight into the morphology of different aggregates
formed in polymer solutions.Comment: 20 pages, 8 figures To appear in PR
Performance of crossbred dairy Friesian calves fed two levels of Saccharomyces cerevisiae: Intake, digestion, ruminal fermentation, blood parameters and faecal pathogenic bacteria
11 páginas, 6 tablas.The effect of feeding two levels of Saccharomyces cerevisiae on the performance of crossbred Friesian calves was investigated. Twenty-four neonatal male Friesian × Baladi calves (35·5 ± 0·25 kg of initial body weight) were randomly assigned in a completely randomized design into three experimental groups for 90 days (eight calves per group). Calves fed their diets without yeast (S. cerevisiae) were considered as Control, while the diets of other calves were supplemented daily either with 2·5 g (YL diet) or with 5 g (YH diet) of yeast per calf. Calves fed the YH diet showed increased feed intake, while dry matter and fibre digestibilities were increased in calves fed YH and YL diets. Calves fed YL and YH diets showed lower ruminal ammonia-N and higher total volatile fatty acids, acetate and propionate concentrations than Control calves. Both YH and YL calves showed increased plasma concentrations of total protein, globulin and glucose and decreased cholesterol and triglycerides concentrations. Calves' final weight and daily gain were increased with S. cerevisiae yeast supplemented diets. After 42 days of experiment, Clostridium spp., Escherichia coli and Enterobacteria spp. counts were down to undetectable levels in the faeces of calves fed S. cerevisiae additive. It could be concluded that adding S. cerevisiae to milk-fed calves increased feed utilization and improved pre-weaned calf performance and health status, reducing faecal pathogenic bacteria. Copyright © Cambridge University Press 2016.Peer reviewe
Isolation of Cellular Clones of Murine Melanoma Resistants to the Photodynamic Therapy and Characterization of Some Mechanisms Involved in the Radioresistance
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Relationship between latent and rebound viruses in a clinical trial of anti-HIV-1 antibody 3BNC117.
A clinical trial was performed to evaluate 3BNC117, a potent anti-HIV-1 antibody, in infected individuals during suppressive antiretroviral therapy and subsequent analytical treatment interruption (ATI). The circulating reservoir was evaluated by quantitative and qualitative viral outgrowth assay (Q2VOA) at entry and after 6 mo. There were no significant quantitative changes in the size of the reservoir before ATI, and the composition of circulating reservoir clones varied in a manner that did not correlate with 3BNC117 sensitivity. 3BNC117 binding site amino acid variants found in rebound viruses preexisted in the latent reservoir. However, only 3 of 217 rebound viruses were identical to 868 latent viruses isolated by Q2VOA and near full-length sequencing. Instead, 63% of the rebound viruses appeared to be recombinants, even in individuals with 3BNC117-resistant reservoir viruses. In conclusion, viruses emerging during ATI in individuals treated with 3BNC117 are not the dominant species found in the circulating latent reservoir, but frequently appear to represent recombinants of latent viruses
DC-electric-field-induced and low-frequency electromodulation second-harmonic generation spectroscopy of Si(001)-SiO interfaces
The mechanism of DC-Electric-Field-Induced Second-Harmonic (EFISH) generation
at weakly nonlinear buried Si(001)-SiO interfaces is studied experimentally
in planar Si(001)-SiO-Cr MOS structures by optical second-harmonic
generation (SHG) spectroscopy with a tunable Ti:sapphire femtosecond laser. The
spectral dependence of the EFISH contribution near the direct two-photon
transition of silicon is extracted. A systematic phenomenological model of the
EFISH phenomenon, including a detailed description of the space charge region
(SCR) at the semiconductor-dielectric interface in accumulation, depletion, and
inversion regimes, has been developed. The influence of surface quantization
effects, interface states, charge traps in the oxide layer, doping
concentration and oxide thickness on nonlocal screening of the DC-electric
field and on breaking of inversion symmetry in the SCR is considered. The model
describes EFISH generation in the SCR using a Green function formalism which
takes into account all retardation and absorption effects of the fundamental
and second harmonic (SH) waves, optical interference between field-dependent
and field-independent contributions to the SH field and multiple reflection
interference in the SiO layer. Good agreement between the phenomenological
model and our recent and new EFISH spectroscopic results is demonstrated.
Finally, low-frequency electromodulated EFISH is demonstrated as a useful
differential spectroscopic technique for studies of the Si-SiO interface in
silicon-based MOS structures.Comment: 31 pages, 14 figures, 1 table, figures are also available at
http://kali.ilc.msu.su/articles/50/efish.ht
Extending reference assembly models
The human genome reference assembly is crucial for aligning and analyzing sequence data, and for genome annotation, among other roles. However, the models and analysis assumptions that underlie the current assembly need revising to fully represent human sequence diversity. Improved analysis tools and updated data reporting formats are also required
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