Production and absorption of nitric oxide gas in the nose

Some nitric oxide gas (NO) produced in the sinuses and nasal cavity is absorbed before leaving the nose. To measure production and absorption, we introduced NO at different concentrations into one nostril while sampling the NO leaving the opposite nostril with the soft palate closed. The quantity of NO gas produced in six normal subjects (amount leaving plus the amount absorbed) averaged 352 nl/min and was the same at gas flows ranging from 8 to 347 ml/min and at 10 l/min. An absorption coefficient A was calculated by dividing the amount of NO absorbed by the concentration leaving the nose. A ranged from 17 ml/min at a nasal gas flow of 8 ml/min to an A of 24 ml/min at a nasal gas flow of 347 ml/min. The calculated rates of production and absorption did not change when gas flow rate was increased, suggesting diffusion equilibrium. The amount of uptake of NO in the nasal mucosa can be explained by its solubility coupled with tissue and blood reactivity.     

Warp Processing: Dynamic Translation of Binaries to FPGA Circuits

Warp processing dynamically and transparently transforms an executing microprocessor's binary kernels into customized field-programmable gate array (FPGA) circuits, commonly resulting in 2X to 100X speedup over executing on microprocessors. A new architecture and set of dynamic CAD tools demonstrate warp processing's potential.     

Temporal integration in the acoustic startle reflex of the rat.

Exposed 6 male albino rats to 6,900 Hz tone pulses with durations of .25-64 msec. and intensities of 80-125 db. re .0002 dyne/cm2. Startle amplitudes increased with duration in a manner suggestive of an exponential function distorted by the failure of the auditory system to reflect faithfully prolonged intense sounds. 5 other male albino rats were exposed to pairs of 1-msec pulses at 125 db., having interpulse intervals ranging 1-11 msec. For pulses separated by 3 msec. or more, response amplitudes demonstrated a decaying exponential summation function with a time constant of 3 msec. Results are in accord with established principles of reflex function and organization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modification of the rat's startle reaction by termination of antecedent acoustic signals.

Conducted 4 experiments with 24 male albino rats relating inhibition and facilitation of the startle response, elicited by an intense auditory stimulus, to the offset of a 70-db continuous acoustic signal. Data indicate that if the antecedent signal terminated 10-1000 msec before the startle-eliciting stimulus, the amplitude of the startle response was reduced. If offset occurred less than 10 msec prior to the startle-eliciting stimulus, the response latency was reduced. Results are consistent with previous research employing weak antecedent acoustic signal onset. The overall configuration of the results suggests that activity in brain centers mediating the startle reflex may be an early component of the orienting reflex arc. (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Estimation of the surface area and volume of the retinal capillary basement membrane using the stereologic method of vertical sections

The modern stereologic method of vertical sections was applied to the retina as a means of generating unbiased estimates of three-dimensional structure. The method is illustrated with real data on the volume and surface area of the capillary basement membrane from the central retina of the rat. Novel methods of estimating the volume of retina sampled and of creating accurate vertical sections are described. The advantages of using stereologic methods to generate quantitative information on the three-dimensional structure of the retina are discussed and compared to those of previous quantitative methods that provide data on two-dimensional structure only.     

Development of positron emission particle tracking for studying laminar mixing in Kenics static mixer

Positron emission particle tracking (PEPT) is a flow visualisation technique that has found application in a wide range of processes. In this work, PEPT has been used to study laminar flow of a high viscosity Newtonian and non-Newtonian fluid in a Kenics static mixer (KM). Through analysis of the trajectories of many hundreds of passes of the tracer particle through the mixer, it is possible to compute the overall flow field and to visualise how the fluid twists and folds as it passes along the mixer. Eulerian velocity maps plotted for the Newtonian and non-Newtonian fluids showed that the length required for the flow to develop is shorter for the non-Newtonian fluid than the Newtonian. The stretching and folding mechanism of mixing was observed by grouping the trajectories into clusters according to whether the trajectory passes to the left or right of the blade at the transition between elements. Those trajectories making the same L–R–L decision tended to remain in the same striation through two or three elements until that striation became stretched and folded back on itself, sandwiching other layers. It is clear that the PEPT data is rich and powerful. We are hopeful that the techniques we develop for the flow and mixing in the Kenics mixer will be applicable to studying more complex laminar flows.