The medical records of 12 horses that had cataracts removed by use of phacofragmentation were reviewed. Cataracts were removed from 16 eyes in horses ranging in age from 2 months to 15 years. ...Complications after surgery included corneal ulcers in 13 eyes, diffuse corneal edema in 5 eyes, and uncontrollable uveitis in 3 eyes. Follow-up information was obtained in all horses from 1 month to 3.5 years after surgery. Visual results were judged good by owners or veterinarians in 10 of the horses.
Feed grain suspected of causing death in a group of pigs was evaluated for toxic potential in chickens. The contaminated grain sorghum mixture was examined visually and contained 3.7% Cassia ...occidentalis and 1.6% Cassia obtusifolia seeds by weight. Thirty-two chicks were fed a sample of this suspect grain sorghum mixture. Chickens receiving the contaminated grain lost weight rapidly, exhibited clinical signs typical of intoxication with Cassia spp., and by day 16 were severely debilitated. Necropsy and histologic and electron microscopic examinations demonstrated a skeletal and cardiac degenerative myopathy consistent with intoxication by Cassia occidentalis. These toxicologic investigations verified the toxic potential of the contaminated sorghum mixture for chickens, and these comparative observations support prior diagnostic efforts implicating Cassia spp. as a cause of illness in swine.
To develop reliable computer models for the bluff body flow and transport of pollutants or chemical and biological (CB) agents in urban environments requires accurate measurements of the basic flow ...fields for carefully controlled, well-known conditions. Fluid modeling in an industrial wind tunnel provides an opportunity to produce accurate simulations of the bluff body flow and transport of urban pollution or of CB agents associated with urban terrorism incidents. A basic building shape, the Wind Engineering Research Field Laboratory building (WERFL) at Texas Tech University, is used for this study. The urban street canyon was represented by a 1:50 scale WERFL model that was surrounded by models of similar dimensions. These buildings were arranged in various symmetric configurations with different separation distances and different numbers of surrounding building. A series of measurements is made over a generic urban street canyon arrangement using flow visualization, anemometry, pressure transducer and gas chromatography. The experimental data include visualization, velocity and turbulence intensity profiles, surface pressure on the building and dispersion of releasing gas. Results are compared to three-dimensional numerical models of the same configuration using the commercial code, FLUENT 5.3. The effects of grid resolution, boundary conditions, source placement and selection of turbulence model (kappa-epsilon, RNG kappa-epsilon, Reynolds stress, etc.) are examined in a series of sensitivity calculations.
Abstract
The forward-flank convergence boundary (FFCB) in supercells has been well documented in many observational and modeling studies. It is theorized that the FFCB is a focal point fore ...baroclinic generation of vorticity. This vorticity is generally horizontal and streamwise in nature, which can then be tilted and converted to mid-level (3-6 km AGL) vertical vorticity. Previous modeling studies of supercells often show horizontal streamwise vorticity present behind the FFCB, with higher resolution simulations resolving larger magnitudes of horizontal vorticity. Recently, studies have shown a particularly strong realization of this vorticity called the streamwise vorticity current (SVC). In this study, a tornadic supercell is simulated with the Bryan Cloud Model at 125-m horizontal grid spacing, and a coherent SVC is shown to be present. Simulated range-height indicator (RHI) data show the strongest horizontal vorticity is located on the periphery of a steady-state Kelvin-Helmholtz billow in the FFCB head. Additionally, similar structure is found in two separate observed cases with the Texas Tech University Ka-band (TTUKa) mobile radar RHIs. Analyzing vorticity budgets for parcels in the vicinity of the FFCB head in the simulation, stretching of vorticity is the primary contributor to the strong streamwise vorticity, while baroclinic generation of vorticity plays a smaller role.
Protein phosphorylation and dephosphorylation systems modulate many cellular activities and have recently been implicated in the in vitro transport of newly synthesized proteins. Here we show that ...polarized transport from the Golgi to the plasma membrane in intact MDCK cells is regulated by phosphorylation-dephosphorylation. Transport is inhibited by the phosphatase inhibitor okadaic acid and is stimulated by the kinase inhibitor staurosporine. Stimulation of apical transport exceeds stimulation of basolateral transport by up to 5-fold. We also find that the G protein activator aluminum fluoride, which stimulates transport to the surface at low fluoride concentrations as previously reported, inhibits transport at higher concentrations. In the nonpolarized fibroblast cell line CV-1, neither staurosporine nor aluminum fluoride stimulates transport to the cell surface. Our results suggest that the phosphorylation-dephosphorylation system, like the G protein, may be involved in the specialized sorting process characteristic of polarized cells. We show some evidence that these two mechanisms of regulation may act through common intermediates.
During avian egg production, oestrogen mediates marked increases in hepatic lipid production and changes in the diameter of assembled very-low density lipoprotein (VLDL). A nearly complete shift from ...generic VLDL ( approximately 70 nm in diameter), which transports lipids to peripheral tissues, to yolk-targeted VLDL (VLDLy) ( approximately 30 nm), which supplies the yolk with energy-rich lipid, has been observed in the plasma of laying domestic fowl. We validated an established dynamic laser scattering technique for a passerine songbird Taeniopygia guttata, the zebra finch, to characterize the dynamics of VLDL particle diameter distribution in relation to egg production. We predicted that non-gallinaceous avian species that have not been selected for maximum egg production would exhibit less dramatic shifts in lipid metabolism during egg production. As predicted, there was considerable overlap between the VLDL particle diameter distributions of laying and non-laying zebra finches. But unexpectedly, non-laying zebra finches had VLDL diameter distributions that peaked at small particles and had relatively few large VLDL particles. As a result, laying zebra finches, in comparison, had diameter distributions that were shifted towards larger VLDL particles. Nevertheless, laying zebra finches, like laying chickens, had larger proportions of particles within proposed VLDLy particle diameter ranges than non-laying zebra finches (e.g. sVLDLy: 50% vs 37%). Furthermore, zebra finches and chickens had similar modal (29.7 nm in both species) and median (32.7 nm vs 29.6 nm) VLDL particle diameters during egg production. Therefore, although zebra finches and chickens exhibited opposing directional shifts in VLDL particle diameter distribution during egg production, the modifications to VLDL particle structure in both species resulted in the realization of a common goal, i.e. to produce and maintain a large proportion of small VLDL particles of specific diameters that are capable of being incorporated into newly forming egg yolks.
Avian reproduction is generally timed to synchronize chick-rearing with periods of increased food abundance. Consequently, the energetically demanding period of egg production may coincide with ...periods of lower food availability, fluctuating temperature and more unstable weather. Little is known about the physiological mechanisms underlying temperature-induced variation in egg production. We therefore examined the influence of low ambient temperature (7 degrees C vs 21 degrees C) on reproductive output (e.g. egg mass, clutch size, laying interval, laying rate), daily food consumption and lipid variables in zebra finches Taeniopygia guttata. When faced with egg production at 7 degrees C, laying zebra finches increased energy intake by 12.67 kJ day(-1), and were thus able to maintain body condition (e.g. body mass, fat and muscle score) and circulating triacylglyceride at levels comparable to those at 21 degrees C. However, when producing eggs at 7 degrees C, females took longer to initiate egg laying (6.5 vs 6.1 days at 21 degrees C), and ultimately laid fewer eggs (5.5 vs 6.0 eggs) at a slower rate (0.90 eggs day(-1) vs 0.95 eggs day(-1)). These temperature-related declines in reproductive output were accompanied by decreases in modal (from 36.6 at 21 degrees C to 24.3 nm at 7 degrees C) and median very low density lipoprotein (VLDL) particle diameter (from 29.6 to 26.4 nm) and in the proportion of VLDL particles that were capable of passing through the pores in the ovary to access the developing ovarian follicles (i.e. particles with diameters between 25 and 44 nm; from 45.90% to 32.55%). However, variation in reproductive output was not related to any static concentration or structural measure of VLDL. Therefore, other temperature-dependent mechanisms must be involved in the physiological processes that regulate reproductive output of passerine birds at low ambient temperatures.
The purpose of this study was to determine the separate and combined effects of clenbuterol (CB) administration and interval training on running performance and myosin light-chain (MLC) isoform ...expression in mouse skeletal muscle. Mice were randomly assigned to one of four treatment groups: 1) control (Con), 2) exercise (Ex), 3) drug (CB), or 4) exercise + drug (Ex + CB). CB and Ex + CB mice were given CB (1.6 mg/kg) orally 4 days/wk. Ex and Ex + CB mice were trained 4 days/wk on a motorized treadmill (3 sets of 3 min, 36-40 m/min, 10-17% grade, 30-s recovery). After 8 wk of treatment, exercise conditioning increased total work performed 58% in the Ex group during a run-to-exhaustion treadmill test, whereas CB decreased total work by 25% in the CB group; in combination with exercise training, CB treatment eliminated the Ex-induced increase in work. Polyacrylamide gel electrophoresis indicated that run training, CB treatment, or a combination did not (P > 0.01) promote changes in fast and slow MLC isoforms in the soleus, gastrocnemius, or tibialis anterior muscles. Although not different from each other after 8 wk, CB and Ex + CB treatments produced significantly greater values than Con and Ex for the following variables: muscle mass (17-46%), total protein (22-50%), and myofibrillar protein (19-53%). It was concluded that CB decreases exercise performance and that the combination of Ex and CB have antagonistic effects on running performance; the two treatments do not interact to diminish the anabolic effects of CB on skeletal muscle and do not alter MLC isoform profiles.
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