High Density Measurements Research Articles

Time course and quantification of changes in cochlear integrity observed in commercially raised broiler chickens

Extensive cochlear hair cell damage and loss occurs in aged broiler chickens. We describe the time course and several characteristics of this decline in cochlear integrity in 19-, 30-, 38- and 66-week-old commercially raised broiler chickens. The 19-week-old group is normal and serves as a baseline for comparison. Generally, cochlear damage increases in severity and percent length of the cochlea with age. Hair cell density increases from the base to the apex. Density is similar across the groups in regions of the cochlea that sustained little or no damage, and decreases in regions of extreme damage. Counts of normal and abnormal hair cells are inversely related. A subset of 66-week-old birds has higher density measurements and increased hair cell counts in the apical region of the cochlea. The progressive damage found in these commercially raised birds is described in the context of both the effects of age and noise exposure on the auditory system. Two additional groups of birds were raised at the University of Kansas Medical Center in a quieter environment to determine the cause of the damage seen in age-matched commercially raised birds. These cochleae are largely normal; a small number displayed damage. This suggests that noise exposure exacerbates naturally occurring cochlear degradation.

Analysis of growth of multicellular tumour spheroids by mathematical models.

We wished to determine the applicability of previously proposed deterministic mathematical models to description of growth of multicellular tumour spheroids. The models were placed into three general classes: empirical, functional and structural. From these classes, 17 models were applied systematically to growth curves of multicellular tumour spheroids used as paradigms of prevascular and microregional tumour growth. The spheroid growth curves were determined with uniquely high density of measurements and high precision. The theoretical growth curves obtained from the models were fitted by the weighted least-squares method to the 15 measured growth curves, each corresponding to a different cell line. The classical growth models such as von Bertalanffy, logistic and Gompertz were considered as nested within more general models. Our results demonstrate that most models fitted the data fairly well and that criteria other than statistical had to be used for final selection. The Gompertz, the autostimulation and the simple spheroid models were the most appropriate for spheroid growth in the empirical, functional and structural classes of models, respectively. We also showed that some models (e.g. logistic, von Bertalanffy) were clearly inadequate. Thus, contrary to the widely held belief, the sigmoid character of a three or more parameter growth function is not sufficient for adequate fits.

A geophysical tracking and data logging system: Description and case history

Oak Ridge National Laboratory has developed an Ultrasonic Ranging and Data System (USRADS) and interfaced the system with a Geonics EM31 terrain conductivity meter. The system tracks the EM31 operator’s position by measuring the traveltime of ultrasonic pulses from a transducer carried in a backpack, to microphones mounted on stationary receivers deployed in the survey area. A microprocessor‐controlled radio transmitter, also carried in the backpack, transmits the terrain conductivity data to a mobile base station (van or truck), where the EM31’s X-Y position, and the electromagnetic quadrature and in‐phase readings are automatically recorded each second by a portable computer. USRADS can track the surveyor for distances of up to about 120 m from the base station with an accuracy of about 10 cm. USRADS potentially offers several advantages for surface geophysical surveys: (1) when elevations are not required, USRADS saves time and money because a measurement grid does not have to be surveyed before the geophysical work begins, (2) data are directly recorded by a portable computer and are available for analysis in the field, and (3) refining or expanding the coverage of an anomaly does not require additional surveying to add extra grid points. We discuss a field study where we surveyed roughly [Formula: see text] of Solid Waste Storage Area 4 (SWSA 4) on the Oak Ridge Reservation collecting over 2700 in‐phase and quadrature measurements in 45 minutes. The high density of measurements provided sharp resolution of waste trench boundaries.

瀬戸内海大型水理模型における流れの可視化

The hydraulic model experiment for a tidal basin requires a log term flow measurement in wide area, keeping its spatial high-measurement density. To fulfill these requirements, we developed an image processing system. The system installs a optical video disk recorder, A/D and D/A converter with LUT and can record successively four visualized flow images at the same time provided that a proper time interval is given. We use many white plastic balls as floats to visualize flows and require the system to process the float images with a high speed. This image processing is done by the hardware of the A/D and D/A converter which turns over the processed data to the float analysis.The float analysis adopted here lays stress on unique pairing of floats and requires their coordinates and members around the float to be paired in two scenes at different time. A pairing algorithm is proposed and tested by the experiment data which is obtained in the Seto Inland Sea hydraulic model and covers flows around islands and bay mouths.

The Mesoscale and Microscale Structure and Organization of Clouds and Precipitation in Midlatitude Cyclones. Part XIV: Three-Dimensional Airflow and Vorticity Budget of Rainbands in a Warm Occlusion

Two rainbands in a young, warm occlusion are examined using dual-Doppler radar data and supporting mesoscale measurements. The high density of measurements permits the structure of the weak vertical motions associated with the precipitation to be resolved. Kinematic fields are described with respect to the small-scale precipitation cores that made up two rainbands. The three-dimensional motions in this core-relative frame provide insights into the relationship between the kinematic and precipitation fields. The rainbands were situated near the centers of cyclonic vorticity and upward motion in the occlusion. They were oriented perpendicular to the wind shear in the vertical and they appeared to be maintained through the interaction of small-scale (∼5 km) updrafts and band-scale (∼40 km), nondivergent, cyclonic circulations. Updrafts, forced by convergence in the boundary layer ahead of the surface occlusion and ahead of the cold air aloft, enhanced the growth of precipitation at and above the level of the band-scale cyclonic circulations. These circulations played an important role in determining the widths of the rainbands. The primary source of vertical vorticity in one of the rainbands was the tilting of the horizontal vorticity associated with the shear in the vertical of the wind across the rainband.

Global Brightness Temperature Spectra at High Wavenuinbers Utilizing Satellite Microwave Measurements

Abstract Satellite microwave brightness temperature (radiance) measurements represent weighted mean temperatures in a certain atmospheric layer. The high density of measurements along a polar-orbiting satellite track allows estimates of the brightness temperature variance spectrum at high meridional wavenumbers. Global data from the Nimbus 6 SCAMS microwave instrument sensitive to the 100–300 mb layer have been analyzed for 30 days in August 1975. The results reveal that the brightness temperature variance spectrum can be fit to the form km over the range k=22 to 59 (horizontal wavelengths 1800 to 700 km). Using 95% confidence intervals, the fit yields m = −3.1±0.3 These results appear to have significance for estimates of energy cascade between different motion scales in the very high wavenumber regime.