Holographic Chern-Simons Theories

Chern-Simons theories in three dimensions are topological field theories that may have a holographic interpretation for suitable chosen gauge groups and boundary conditions on the fields. Conformal Chern-Simons gravity is a topological model of 3-dimensional gravity that exhibits Weyl invariance and allows various holographic descriptions, including Anti-de Sitter, Lobachevsky and flat space holography. The same model also allows to address some aspects that arise in higher spin gravity in a considerably simplified setup, since both types of models have gauge symmetries other than diffeomorphisms. In these lectures we summarize briefly recent results.Comment: 20 pp, invited lectures prepared for the 7th Aegean Summer School "Beyond Einstein's Theory of Gravity", 201

The Effect of Stevia Rebaudiana on Serum Omentin and Visfatin Level in STZ-Induced Diabetic Rats

Recently the role of adipocytokines in relationship to incidence of diabetes has been demonstrated. One of the medicinal plants that are used in the treatment of diabetes is stevia. This study investigates the effect of stevia on serum omentin and visfatin levels as novel adipocytokines in diabetic induced rats to find potential mechanisms for the anti hyperglycemic effect of stevia. Forty male wistar rats weighing 180–250 g were induced with diabetes by intraperitoneal injection of streptozotocin (STZ). The animals were divided into 5 groups of 8. Rats in group 1 (non-diabetic control) and group 2 (diabetic control) were treated with distilled water, and the rats in the treated groups, group 3 (T250), group 4 (T500), and group 5 (T750) were treated with stevia, gavaged every day at 9 a.m. in doses of 250, 500, and 750 mg/kg, respectively. At the end of the study significant reductions in fasting blood sugar (FBS), the homeostasis model assessment insulin resistance (HOMA-IR), triglyceride (TG), alkaline phosphatase (ALP), and Omentin level were found in groups 3 and 4 in comparison with group 2. Pancreatic histopathology slides demonstrated that stevia extract did not induce any increase in the number of β-cells. The conclusion is that prescription of stevia in the doses of 250 and 500 mg/kg/d decreases the omentin level indirectly via activating insulin sensitivity and lowering blood glucose in STZ-induced diabetic rats. KEYWORDS. Diabetes, omentin, stevia, visfati

A practical CFD modeling approach to estimate outlet boundary conditions of industrial multistage spray dryers: Inert particle flow field investigation

Industrial multistage spray drying systems often have limited in situ process measurements to provide sufficient information for computational fluid dynamics (CFD) simulations of the primary drying chamber. In this case study on the spray dryer at Davis Dairy Plant (South Dakota State University), uncertainties were encountered in specifying the outlet boundary conditions of the spray drying chamber with two outlets: the side outlet and the bottom outlet leading to the second stage external vibrating bed. Using the available data on the vacuum pressure of the chamber, a numerical framework was introduced to approximate suitable outlet boundary conditions for the drying chamber. The procedure involved analyzing the ratio of the airflow rate between the two outlets and using a pseudo-tracer inert particle injection analysis. The goal of this approach was to determine a suitable range of outlet vacuum pressure that will lead to realistic particle movement behaviors during the actual plant operation. The protocol developed here will be a useful tool for CFD modeling of large scale multistage spray drying systems. Abbreviations: ARC: Australian Research Council; CFD: Computational Fluid Dynamics; FFT: Fast Fourier Transform; MCC: Micellar Casein Concentrate; PRESTO: Pressure Staggering Option; SDSU: South Dakota State University; SIMPLE: Semi − Impilicit Method for Pressure Linked Equations; WPC: Whey Protein Concentrate

Microwire fibers for low-loss THz transmission

This paper was presented at Smart Structures, Devices, and Systems, which was a sub-conference contained within Smart Materials, Nano- and Micro-Smart Systems Symposium (10-13 December 2006 : Adelaide, South Australia). This paper was published in Smart Structures, Devices, and Systems III, edited by Said F. Al-Sarawi, Proc. of SPIE Vol. 6414, 64140I and is made available as an electronic reprint with permission of SPIE. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.In this paper, we will investigate microwire fibers for low-loss terahertz transmission. Microwires, air-clad wire waveguides with diameter smaller than the operating wavelength (a few μm), have an enhanced evanescent field and tight wave confinement resulting in a low loss waveguide structure for the terahertz (T-ray) frequency regime. Based on our experimental data for the bulk material absorption of four glasses (F2, SF6, SF57 and Bismuth) and a polymer (PMMA), we calculate the normalized field distribution, power fraction outside the wire and effective loss. It will be shown that regardless of material, the effective loss of all microwires converges to the same order < 0.01 cm -1.Shaghik Atakaramians, Shahraam Afshar Vahid, Bernd M. Fischer, Heike Ebendorff-Heidepriem, Tanya Monro and Derek Abbotthttp://spie.org/Documents/ConferencesExhibitions/au06-final.pd

On massive gravitons in 2+1 dimensions

The Fierz-Pauli (FP) free field theory for massive spin 2 particles can be extended, in a spacetime of (1+2) dimensions (3D), to a generally covariant parity-preserving interacting field theory, in at least two ways. One is "new massive gravity" (NMG), with an action that involves curvature-squared terms. Another is 3D "bigravity", which involves non-linear couplings of the FP tensor field to 3D Einstein-Hilbert gravity. We review the proof of the linearized equivalence of both "massive 3D gravity" theories to FP theory, and we comment on their similarities and differences.Comment: 6 pages, to appear in the proceedings of the Spanish Relativity Meeting ERE2009, Bilbao; minor changes, reference adde

On the effect of turbulence models on CFD simulations of a counter-current spray drying process

Accurate modeling of the flow field by means of capturing turbulence is crucial in CFD simulations. However, choosing the appropriate turbulence model remains quite challenging for simulating spray drying applications. Only a few studies have touched on this issue, although experimentally validated comparisons throughout the dryer are rare. This work aims to provide an assessment of five different turbulence models (RNG k − ε standard, BSL and SST k − ω as well as transition SST) in terms of the predicted flow field throughout a lab-scale counter-current spray dryer. None of the tested models could initially provide a satisfactory match with locally measured temperatures within the chamber. The popular choice RNG k − ε model led to highest discrepancies, while the k − ω variants performed only slightly better. All these models under-predicted the dissipation of the central hot air jet. Modification to the k − ω variant's characteristic constant to allow increased production of turbulence led to satisfactory agreement between the measurements and simulation results. Extended analysis revealed that different turbulence models produced significantly different drying histories. Only the k − ω SST variant with modified constant could provide predictions close to measured outlet particle moisture content and air conditions. The RNG model proved unsuitable due to unrealistic results with particle injection as well. The differences in predictions with injection among the models were attributed to different transient self-sustained air fluctuation behavior predicted within the chamber. This work will be useful in the selection of turbulence models which is fundamental to accurate CFD modeling of spray dryers

Effect of shark cartilage derived protein on the NK cells activity

Context: Shark cartilage has been used for its beneficial effects on various diseases. There are evidences, that shark cartilage stimulates cellular and humoral immune responses, which makes it an anti-tumor and immunomodulator candidate. Objective: The immunostimulatory effect of shark cartilage derived proteins on the cytotoxic activity of natural killer (NK) cells from healthy human peripheral blood mononuclear cells was studied. Material and methods: The shark cartilage was extracted and its bioactive proteins were purified using ion-exchange chromatography (DE-52) and sequential fractionation on Amicon ultrafiltration membranes. The effect of each protein fraction on the modulation of cytotoxic activity of NK cells, as effectors, against K562, as target cells, was assayed by enzymatic lactate dehydrogenase test. Results: The most immunostimulatory effect on the cytotoxic activity of NK cells was observed for AR10 fraction, containing proteins with molecular weight of about 14.5kDa on the reducible discontinuous sodium dodecyl sulfate polyacrylamide gel electrophoresis. Discussion: Among the examined shark cartilage derived proteins, the most immunostimulatory effects on the NK cells cytotoxicity was found for AR10 fraction with molecular weight of about 14kDa. We propose—the direct interactions of shark cartilage derived proteins with NK cells surface receptors may lead to the enhancing in the cytotoxic activity of NK cells. Conclusion: Thus AR10 fraction, proteins of about 14.5kDa, has a novel immunostimulatory effect on the NK cells activity in vitro and if confirmed by in vivo trials, it may lead to its future clinical applications as, immunotherapy of cancer, HIV, and augmentation of host immune system related immunodeficiency disorders. Keywords: Immunostimulation, purification, shark cartilage, K562, NK cel

Highly nonlinear and dispersion-flattened fiber design for ultrafast phase-sensitive amplification

The properties of phase-sensitive amplification (PSA) in highly nonlinear fibers are studied. We present a soft glass fiber designed for high nonlinearity and broadband, low dispersion and simulate its performance as a PSA device for ultrafast bitrate signals at 640 Gb/s. The effect of the fiber design parameters on its PSA performance have been studied and the final design has been optimized using a genetic algorithm to have a high nonlinearity and low, flat dispersion. This design has subsequently been compared to other highly nonlinear fibers in order to highlight the effect of both using soft glass and the design and optimization technique. Modelled fiber performance shows squeezing of phase noise in a 5 m length of fiber with 32 dBm total power in the signal and pumps. The fiber length we have used in our model is two orders of magnitude shorter than the state of the art silica based PSA devices for comparable power levels. In addition, fabrication tolerance modelling is done to show that our fiber design is better able to manage fluctuations in the dispersion due to the high nonlinearity.H. Tilanka Munasinghe, Shahraam Afshar Vahid, and Tanya M. Monr

Melilotoside Derivatives from Artemisia splendens (Asteraceae)

A combination of solid-phase-extraction (SPE) and reversed-phase preparative high-performance liquid chromatography (prep-HPLC) of the methanolic extract of the aerial parts of Artemisia splendens (common name: “Asia Minor Wormwood”), an endemic Iranian species, afforded Z- and E-melilotosides (1 and 2), Z- and E-4-methoxy-melilotosides (3 and 4), and a new dimer, bis-ortho-Z-melilotoside (5, named: splendenoside). Whilst the structures of these compounds (1-5) were elucidated unequivocally by spectroscopic means, the in vitro free-radical-scavenging property of 1-5 was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. This is the first report on the occurrence of any melilotoside derivatives in the genus Artemisia

Melilotoside derivatives from Artemisia splendens (Asteraceae)

All rights reserved.A combination of solid-phase-extraction (SPE) and reversed-phase preparative high-performance liquid chromatography (prep-HPLC) of the methanolic extract of the aerial parts of Artemisia splendens (common name: “Asia Minor Wormwood”), an endemic Iranian species, afforded Z- and E-melilotosides (1 and 2), Z- and E-4-methoxy-melilotosides (3 and 4), and a new dimer, bis-ortho-Z-melilotoside (5, named: splendenoside). Whilst the structures of these compounds (1-5) were elucidated unequivocally by spectroscopic means, the in vitro free-radical-scavenging property of 1-5 was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. This is the first report on the occurrence of any melilotoside derivatives in the genus Artemisia. © 2016 ACG Publications