Multi-dimensional Numerical Simulation of Wind-induced Flow and Transport Processes in an Urban Water System

Integrated Modeling of Hydro-System

Solving Modal Equations of Motion with Initial Conditions Using MSC/NASTRAN DMAP

By utilizing MSC/NASTRAN DMAP (Direct Matrix Abstraction Program) in an existing NASA Lewis Research Center coupled loads methodology, solving modal equations of motion with initial conditions is possible using either coupled (Newmark-Beta) or uncoupled (exact mode superposition) integration available within module TRD1. Both the coupled and newly developed exact mode superposition methods have been used to perform transient analyses of various space systems. However, experience has shown that in most cases, significant time savings are realized when the equations of motion are integrated using the uncoupled solver instead of the coupled solver. Through the results of a real-world engineering analysis, advantages of using the exact mode superposition methodology are illustrated

Solving modal equations of motion with initial conditions using MSC/NASTRAN DMAP. Part 1: Implementing exact mode superposition

Within the MSC/NASTRAN DMAP (Direct Matrix Abstraction Program) module TRD1, solving physical (coupled) or modal (uncoupled) transient equations of motion is performed using the Newmark-Beta or mode superposition algorithms, respectively. For equations of motion with initial conditions, only the Newmark-Beta integration routine has been available in MSC/NASTRAN solution sequences for solving physical systems and in custom DMAP sequences or alters for solving modal systems. In some cases, one difficulty with using the Newmark-Beta method is that the process of selecting suitable integration time steps for obtaining acceptable results is lengthy. In addition, when very small step sizes are required, a large amount of time can be spent integrating the equations of motion. For certain aerospace applications, a significant time savings can be realized when the equations of motion are solved using an exact integration routine instead of the Newmark-Beta numerical algorithm. In order to solve modal equations of motion with initial conditions and take advantage of efficiencies gained when using uncoupled solution algorithms (like that within TRD1), an exact mode superposition method using MSC/NASTRAN DMAP has been developed and successfully implemented as an enhancement to an existing coupled loads methodology at the NASA Lewis Research Center

A Gut Analysis Technique for Pinpointing Egg-Specific Predation Events

A universal food immunomarking technique (UFIT) is described for postmortem gut analysis detection of predation on the egg stage of Lygus hesperus Knight (Hemiptera: Miridae). Collops vittatus Say (Coleoptera: Melyridae) and Hippodamia convergens Guerin-Meneville (Coleoptera: Coccinellidae) were fed a single L. hesperus egg that was marked with rabbit and chicken sera proteins. The protein-marked egg remnants were detectable in the guts of the majority of the predators by each sera-specific enzyme-linked immunosorbent assay (ELISA) for 3 to 6 h after a feeding event. A novel technique was then developed to expose protein-marked eggs to predators that simulated the L. hesperus endophytic oviposition behavior. The procedure entailed embedding L. hesperus eggs in an artificial substrate that mimicked the stem of a plant. A predator feeding choice study was then conducted in cages that contained a cotton plant and artificial stems containing endophytic (concealed) and exophytic (exposed) egg patches. The endophytic and exophytic egg treatments were marked with chicken and rabbit protein, respectively. The gut analyses revealed that higher proportions of both predator populations contained remnants of the exophytic egg treatment and L. hesperus eggs were more vulnerable to C. vittatus than H. convergens. This study shows how the UFIT can be used to pinpoint stage-specific feeding activity on two distinct egg exposure treatments (endophytic and exophytic) of the same species.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Fast learning algorithm for Gabor transformation, A

Includes bibliographical references.An adaptive learning approach for the computation of the coefficients of the generalized nonorthogonal 2-D Gabor transform representation is introduced in this correspondence. The algorithm uses a recursive least squares (RLS) type algorithm. The aim is to achieve minimum mean squared error for the reconstructed image from the set of the Gabor coefficients. The proposed RLS learning offers better accuracy and faster convergence behavior when compared with the least mean squares (LMS)-based algorithms. Applications of this scheme in image data reduction are also demonstrated

Citric acid strongly inhibits visceral pain response in mice

Citric acid introduced into the stomach of mice at increasing concentrations of 0.1, 1 or 10 % (4.8 µM-0.48 mM; 95 µmol/kg-9.5 mmol/kg, 0.5 ml) caused dose-dependent inhibition of abdominal constrictions induced 1 h later by i. p. acetic acid injection by -51 % to -69.5 %. When administered at 10 % (0.48 mM, 0.5 ml) 15 min before nociceptive challenge, citric acid inhibited the nociceptive response by 96.8 %. Inhibition of the acetic acid-induced abdominal constrictions was also observed when lower doses of citric acid were introduced into the stomach (0.2 ml of 0.1-1 %; 38.1 µmol/kg-0.38 mmol/kg). The effect was evident as early as 5 min after administration of citric acid into the stomach and with the maximal effect being at 15-30 min after dosing. Lidocaine given orally 5 min prior to citric acid (1 %, 48 µM; 0.38 mmol/kg, 0.2 ml) prevented antinociception by citric acid, but lidocaine given 15 min before oral introduction of citric acid enhanced the citric acid-induced inhibition of the nociceptive response to acetic acid. The antinociceptive effect of orally administered citric acid (1 %, 48 µM; 0.38 mmol/kg, 0.2 ml) was increased by pre-treatment with propranolol (4 mg/kg, s. c.), yohimbine (4 mg/kg, s. c.), guanethidine (32 mg/kg, s. c.), but reduced after treatment with atropine (3 mg/kg, s. c.), which itself increased the nociceptive behavior. Similar inhibition of the acetic acid-induced nociceptive behavior was also observed when sodium citrate (pH 7.21) or 0.1 N HCl (pH 3) or 1 % sucrose solution (0.2 ml) was intragastrically given. It is suggested that citric acid might act to stimulate sensory afferents and that transmission of nociceptive information centrally leads to the activation of descending antinociceptive mechanism to a noxious stimulus

Thymoquinone and curcumin attenuate gentamicin-induced renal oxidative stress, inflammation and apoptosis in rats

The present study was aimed to investigate the possible protective effects of thymoquinone (TQ) and curcumin (Cur) on gentamicin (GM)-induced nephrotoxicity in rats. Rats were divided into four groups as follows: group 1 received normal saline and served as normal controls, group 2 received GM only, group 3 concurrently received GM and TQ and group 4 concurrently received GM and Cur. At day 21, rats were sacrificed and samples were collected for assaying serum tumor necrosis factor alpha (TNF-α), urea and creatinine levels, and renal lipid peroxidation, glutathione (GSH) content as well as glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities. In addition, kidneys were collected for histopathological examination and immunohistochemical determination of the antiapoptotic protein, B-cell lymphoma 2 (Bcl-2). The biochemical results showed that GM-induced nephrotoxicity was associated with a significant increase in serum TNF-α, urea and creatinine as well as renal lipid peroxidation. On the other hand, renal GSH content and GPx and SOD activities were significantly declined. Concomitant administration of either TQ or Cur efficiently alleviated the altered biochemical and histopathological features. In conclusion, both TQ and Cur showed more or less similar marked renoprotective effect against GM-induced nephrotoxicity through their antioxidant, anti-inflammatory and anti-apoptotic efficacies

Blood-brain barrier pericyte importance in malignant gliomas: What we can learn from stroke and Alzheimer's disease

The pericyte, a constitutive component of the central nervous system, is a poorly understood cell type that envelops the endothelial cell with the intended purpose of regulating vascular flow and endothelial cell permeability. Previous studies of pericyte function have been limited to a small number of disease processes such as ischemic stroke and Alzheimer's disease. Recently, publications have postulated a link between glioma stem cell differentiation and pericyte function. These studies suggest that there may be an important interaction of pericytes with tumor cells and other components of the tumor microenvironment in malignant primary glial neoplasms, most notably glioblastoma. This potential cellular interaction underscores the need to pursue more investigations of pericytes in malignant brain tumor biology. In this review, we summarize the functional roles of pericytes, particularly focusing on changes in pericyte biology during response to immune cells, inflammation, and hypoxic conditions. The information presented is based on the available data from studies of pericyte function in other central nervous system diseases but will serve as a foundation for research investigations to further understand the role of pericytes in malignant gliomas

The lifecycle of geotagged data

The world is a big place. At any given instant something is happening somewhere, but even when nothing in particular is going on people still find ways to generate data, such as posting on s