1,317 research outputs found
Dispersive shock waves in the Kadomtsev-Petviashvili and Two Dimensional Benjamin-Ono equations
Dispersive shock waves (DSWs) in the Kadomtsev-Petviashvili (KP) equation and
two dimensional Benjamin-Ono (2DBO) equation are considered using parabolic
front initial data. Employing a front tracking type ansatz exactly reduces the
study of DSWs in two space one time (2+1) dimensions to finding DSW solutions
of (1+1) dimensional equations. With this ansatz, the KP and 2DBO equations can
be exactly reduced to cylindrical Korteweg-de Vries (cKdV) and cylindrical
Benjamin-Ono (cBO) equations, respectively. Whitham modulation equations which
describe DSW evolution in the cKdV and cBO equations are derived in general and
Riemann type variables are introduced. DSWs obtained from the numerical
solutions of the corresponding Whitham systems and direct numerical simulations
of the cKdV and cBO equations are compared with excellent agreement obtained.
In turn, DSWs obtained from direct numerical simulations of the KP and 2DBO
equations are compared with the cKdV and cBO equations, again with remarkable
agreement. It is concluded that the (2+1) DSW behavior along parabolic fronts
can be effectively described by the DSW solutions of the reduced (1+1)
dimensional equations.Comment: 25 Pages, 16 Figures. The movies showing dispersive shock wave
propagation in Kadomtsev-Petviashvili II and Two Dimensional Benjamin-Ono
equations are available at https://youtu.be/AExAQHRS_vE and
https://youtu.be/aXUNYKFlke
Interaction of Colloidal Particles with Surfaces of Biological Significance
The adhesion of colloidal gold on membranes was examined
with an electron microscope with protein on the membrane, on
the colloidal particles and present on both membrane and particles.
The conditions for best adhesion were determined. Quantitative
measurements were caNied out using adhesion to the membrane
to monitor diffusion, centrifugation and electrophoresis of colloidal
particles. Electrophoresis in a centrifugal field was used as a nul
method to determine the charge on the colloidal particle
Interaction of Colloidal Particles with Surfaces of Biological Significance
The adhesion of colloidal gold on membranes was examined
with an electron microscope with protein on the membrane, on
the colloidal particles and present on both membrane and particles.
The conditions for best adhesion were determined. Quantitative
measurements were caNied out using adhesion to the membrane
to monitor diffusion, centrifugation and electrophoresis of colloidal
particles. Electrophoresis in a centrifugal field was used as a nul
method to determine the charge on the colloidal particle
Glandular trichomes and essential oils of Salvia glutinosa L.
The aerial organs of Salvia glutinosa L. bear indumentum with two types of trichomes: simple and multicellular nonglandular trichomes, and stalked and sessile dense glandular trichomes. Glandular trichomes are extremely long-stalked and dense on the stem and calyx surfaces. However, sessile glands are rare on the stem, calyx and leaf adaxial surfaces and dense on the leaf abaxial surface. Secretion accumulates in a subcuticular space and is released to the outside by cuticle rupture. Water distilled essential oil from dried aerial parts of S. glutinosa was analysed by GC/MS. The main constituent was identified as 1-octadecanol (11.6%)
Activation profiles of opioid ligands in HEK cells expressing δ opioid receptors
BACKGROUND: The aim of the present study was to characterize the activation profiles of 15 opioid ligands in transfected human embryonic kidney cells expressing only δ opioid receptors. Activation profiles of most of these ligands at δ opioid receptors had not been previously characterized in vitro. Receptor activation was assessed by measuring the inhibition of forskolin-stimulated cAMP production. RESULTS: Naltrexone and nalorphine were classified as antagonists at δ opioid receptor. The other ligands studied were agonists at δ opioid receptors and demonstrated IC(50 )values of 0.1 nM to 2 μM, maximal inhibition of 39–77% and receptor binding affinities of 0.5 to 243 nM. The rank order of efficacy of the ligands tested was metazocine = xorphanol ≥ fentanyl = SKF 10047 = etorphine = hydromorphone = butorphanol = lofentanil > WIN 44,441 = Nalbuphine = cyclazocine ≥ met-enkephalin >> morphine = dezocine. For the first time these data describe and compare the function and relative efficacy of several ligands at δ opioid receptors. CONCLUSIONS: The data produced from this study can lead to elucidation of the complete activation profiles of several opioid ligands, leading to clarification of the mechanisms involved in physiological effects of these ligands at δ opioid receptors. Furthermore, these data can be used as a basis for novel use of existing opioid ligands based on their pharmacology at δ opioid receptors
Activity of opioid ligands in cells expressing cloned mu opioid receptors
BACKGROUND: The aim of the present study was to describe the activity of a set of opioid drugs, including partial agonists, in a cell system expressing only mu opioid receptors. Receptor activation was assessed by measuring the inhibition of forskolin-stimulated cyclic adenosine mono phosphate (cAMP) production. Efficacies and potencies of these ligands were determined relative to the endogenous ligand β-endorphin and the common mu agonist, morphine. RESULTS: Among the ligands studied naltrexone, WIN 44,441 and SKF 10047, were classified as antagonists, while the remaining ligands were agonists. Agonist efficacy was assessed by determining the extent of inhibition of forskolin-stimulated cAMP production. The rank order of efficacy of the agonists was fentanyl = hydromorphone = β-endorphin > etorphine = lofentanil = butorphanol = morphine = nalbuphine = nalorphine > cyclazocine = dezocine = metazocine ≥ xorphanol. The rank order of potency of these ligands was different from that of their efficacies; etorphine > hydromorphone > dezocine > xorphanol = nalorphine = butorphanol = lofentanil > metazocine > nalbuphine > cyclazocine > fentanyl > morphine >>>> β-endorphin. CONCLUSION: These results elucidate the relative activities of a set of opioid ligands at mu opioid receptor and can serve as the initial step in a systematic study leading to understanding of the mode of action of opioid ligands at this receptor. Furthermore, these results can assist in understanding the physiological effect of many opioid ligands acting through mu opioid receptors
Parametric 3D modelling of nonwovens for mechanical and filtration properties
Parametric 3D modelling of nonwovens for mechanical and filtration propertie
Use of commercial off-the-shelf digital cameras for scientific data acquisition and scene-specific color calibration
Author Posting. © Optical Society of America, 2014. This article is posted here by permission of Optical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Optical Society of America A: Optics, Image Science, and Vision 31 (2014): 312-321, doi:10.1364/JOSAA.31.000312.Commercial off-the-shelf digital cameras are inexpensive and easy-to-use instruments that can be used for quantitative scientific data acquisition if images are captured in raw format and processed so that they maintain a linear relationship with scene radiance. Here we describe the image-processing steps required for consistent data acquisition with color cameras. In addition, we present a method for scene-specific color calibration that increases the accuracy of color capture when a scene contains colors that are not well represented in the gamut of a standard color-calibration target. We demonstrate applications of the proposed methodology in the fields of biomedical engineering, artwork photography, perception science, marine biology, and underwater imaging.T. Treibitz is an
Awardee of the Weizmann Institute of Science—National
Postdoctoral Award Program for Advancing Women in
Science and was supported by NSF grant ATM-0941760.
D. Akkaynak, J. Allen, and R. Hanlon were supported by
NSF grant 1129897 and ONR grants N0001406-1-0202 and N00014-10-1-0989 and U. Demirci by grants R01AI093282,
R01AI081534, and NIH U54EB15408. J. Allen is grateful for
support from a National Defense Science and Engineering
Graduate Fellowship
Ocular metastases from HER2 positive breast carcinoma and the response to combination therapy with Paclitaxel and Trastuzumab: a case report
Drexel University
We present a 3D matching framework based on a many-to-many matching algorithm that works with skeletal representations of 3D volumetric objects. We demonstrate the performance of this approach on a large database of 3D objects containing more than 1000 exemplars. The method is especially suited to matching objects with distinct part structure and is invariant to part articulation. Skeletal matching has an intuitive quality that helps in defining the search and visualizing the results. In particular, the matching algorithm produces a direct correspondence between two skeletons and their parts, which can be used for registration and juxtaposition. 1
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