493 research outputs found
Controlled incremental filtration: a simplified approach to design and fabrication of high-throughput microfluidic devices for selective enrichment of particles.
The number of microfluidic strategies aimed at separating particles or cells of a specific size within a continuous flow system continues to grow. The wide array of biomedical and other applications that would benefit from successful development of such technology has motivated the extensive research in this area over the past 15 years. However, despite promising advancements in microfabrication capabilities, a versatile approach that is suitable for a large range of particle sizes and high levels of enrichment, with a volumetric throughput sufficient for large-scale applications, has yet to emerge. Here we describe a straightforward method that enables the rapid design of microfluidic devices that are capable of enriching/removing particles within a complex aqueous mixture, with an unprecedented range of potential cutoff diameter (below 1”m to above 100”m) and an easily scalable degree of enrichment/filtration (up to 10-fold and well beyond). A simplified model of a new approach to crossflow filtration â controlled incremental filtration â was developed and validated for its ability to generate microfluidic devices that efficiently separate particles on the order of 1â10”m, with throughputs of tens of ”L/min, without the use of a pump. Precise control of the amount of fluid incrementally diverted at each filtration âgapâ of the device allows for the gap size (~20”m) to be much larger than the particles of interest, while the simplicity of the model allows for many thousands of these filtration points to be readily incorporated into a desired device design. This new approach should enable truly high-throughput microfluidic particle-separation devices to be generated, even by users only minimally experienced in fluid mechanics and microfabrication techniques
One-loop Beta Functions for the Orientable Non-commutative Gross-Neveu Model
We compute at the one-loop order the beta-functions for a renormalisable
non-commutative analog of the Gross Neveu model defined on the Moyal plane. The
calculation is performed within the so called x-space formalism. We find that
this non-commutative field theory exhibits asymptotic freedom for any number of
colors. The beta-function for the non-commutative counterpart of the Thirring
model is found to be non vanishing.Comment: 16 pages, 9 figure
On the Effective Action of Noncommutative Yang-Mills Theory
We compute here the Yang-Mills effective action on Moyal space by integrating
over the scalar fields in a noncommutative scalar field theory with harmonic
term, minimally coupled to an external gauge potential. We also explain the
special regularisation scheme chosen here and give some links to the Schwinger
parametric representation. Finally, we discuss the results obtained: a
noncommutative possibly renormalisable Yang-Mills theory.Comment: 19 pages, 6 figures. At the occasion of the "International Conference
on Noncommutative Geometry and Physics", April 2007, Orsay (France). To
appear in J. Phys. Conf. Se
Generalization of the Bollob\'as-Riordan polynomial for tensor graphs
Tensor models are used nowadays for implementing a fundamental theory of
quantum gravity. We define here a polynomial encoding the
supplementary topological information. This polynomial is a natural
generalization of the Bollob\'as-Riordan polynomial (used to characterize
matrix graphs) and is different of the Gur\uau polynomial, (R. Gur\uau,
"Topological Graph Polynomials in Colored Group Field Theory", Annales Henri
Poincare {\bf 11}, 565-584 (2010)) defined for a particular class of tensor
graphs, the colorable ones. The polynomial is defined for both
colorable and non-colorable graphs and it is proved to satisfy the
contraction/deletion relation. A non-trivial example of a non-colorable graphs
is analyzed.Comment: 22 pages, 20 figure
Overview of the parametric representation of renormalizable non-commutative field theory
We review here the parametric representation of Feynman amplitudes of
renormalizable non-commutative quantum field models.Comment: 10 pages, 3 figures, to be published in "Journal of Physics:
Conference Series
The importance of endo-lysosomal escape with lipid nanocapsules for drug subcellular bioavailability
Fostered and left behind alleles in peanut: interspecific QTL mapping reveals footprints of domestication and useful natural variation for breeding
<p>Abstract</p> <p>Background</p> <p>Polyploidy can result in genetic bottlenecks, especially for species of monophyletic origin. Cultivated peanut is an allotetraploid harbouring limited genetic diversity, likely resulting from the combined effects of its single origin and domestication. Peanut wild relatives represent an important source of novel alleles that could be used to broaden the genetic basis of the cultigen. Using an advanced backcross population developed with a synthetic amphidiploid as donor of wild alleles, under two water regimes, we conducted a detailed QTL study for several traits involved in peanut productivity and adaptation as well as domestication.</p> <p>Results</p> <p>A total of 95 QTLs were mapped in the two water treatments. About half of the QTL positive effects were associated with alleles of the wild parent and several QTLs involved in yield components were specific to the water-limited treatment. QTLs detected for the same trait mapped to non-homeologous genomic regions, suggesting differential control in subgenomes as a consequence of polyploidization. The noteworthy clustering of QTLs for traits involved in seed and pod size and in plant and pod morphology suggests, as in many crops, that a small number of loci have contributed to peanut domestication.</p> <p>Conclusion</p> <p>In our study, we have identified QTLs that differentiated cultivated peanut from its wild relatives as well as wild alleles that contributed positive variation to several traits involved in peanut productivity and adaptation. These findings offer novel opportunities for peanut improvement using wild relatives.</p
Comparative efficacy of two fipronil spot-on formulations against experimental tick infestations (Ixodes ricinus) in dogs
A parallel-group-design, randomized, unicentre and blinded controlled study was undertaken to assess the efficacy of a new fipronil-based spot-on formulation applied once to dogs against experimental Ixodes ricinus infestations. Six dogs served as negative controls (group 1), six dogs served as positive controls (group 2) receiving the original fipronil spot-on (FrontlineÂź spot-on Dog, Merial) at a dosage of 0.67Â mL for a dog weighing from 2 to 10Â kg and 1.34Â mL for a dog weighing from 10.1 to 20Â kg and six dogs were treated with a 10% w/v fipronil-based spot-on solution (EffiproÂź Spot-on, Virbac SA) at an identical dosage (group 3, 0.67 mL for a dog weighing from 2 to 10 kg and 1.34 mL for a dog weighing from 10.1 to 20 kg). Each dog was sedated and subsequently infested with 50 unfed adult I. ricinus on daysââ7, â2, 7, 14, 21, 28 and 35. Forty-eight hours after the treatment and 48Â h after each challenge (days â5, 2, 9, 16, 23, 30 and 37), the population of the remaining ticks was assessed for each animal. Geometric mean tick counts obtained were reduced by 99% and 94% on dayâ2 in groups 2 and 3, respectively, compared to the negative control group. Dogs were protected from re-infestations with an efficacy of >90% for 3Â weeks in group 2 and for 5Â weeks in group 3. Both 10% w/v fipronil-based spot-on solutions, despite different vehicles, were equally able to eradicate tick infestation, to prevent new infestations and were equally well tolerated
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