Familial intracranial gliomas Maroun, F B; Jacob, J C; Heneghan, W D ...
Surgical neurology
22, Številka:
1
Journal Article
The pedigree of two interrelated families with 10 affected members suffering from malignant supratentorial gliomas is reported. In addition, three other unrelated families with two members each who ...were treated for different types of brain tumors are described. Genetic implications are discussed.
A statistical inversion procedure is developed for remotely determining the average transverse wind velocity and the atmospheric structure constant at N arbitrary points along a line-of-sight path. ...Linear integral equations are given relating the amplitude correlation function and the amplitude and phase structure functions with the unknown structure constant and wind velocity. It is shown that the standard matrix inversion leads to large variations, as high as 10^{11} percent errors, in the unknown for small data error of one percent; thus the problem is ill posed. The errors are reduced to a suitable level by a statistical procedure that is dependent upon a priori knowledge of the statistics of the unknowns. For the structure constant, a procedure developed by Franklin and others is used, while the wind velocity is determined by modifying the method to include the errors in the structure constant. Computer simulation is used to estimate the error. It is shown that, with an input error of one percent, the rms error in the unknown is only on the order of ten percent. To show the effectiveness of the method, experimental data obtained by a Stanford group are used to determine the wind velocity and the structure constant along the path, yielding reasonable results.
Employing distance education techniques in teaching electrical engineering courses will continue to grow. One of the major obstacles in distance education is providing relevant, hands-on laboratories ...for students. This project is aimed at giving students real-time access to standard laboratory instrumentation and electronic circuits via the internet. Students manipulate real instruments such as oscilloscopes and function generators with mouse clicks, change circuit measurement points, modify circuit connections, and adjust component values. The oscilloscope waveforms and meter readings are measured by real instruments in a central laboratory and the resulting data are sent back to the student’s computer for display. The student can view a list of which experiments are currently available and select an experiment to run. The student activity is recorded for evaluation by the instructor. Overview The growing trend of distance education can severely limit a student’s access to real laboratory equipment. Remote laboratory experiments have been developed that allow students to gain access to real electronic instruments on a schedule that best suits their needs. The remote student can control and observe real electronic instruments, circuits and circuit elements in the same manner that a traditional, in-lab, student can. This is not a simulated laboratory experience. Accurate, graphical representations of the specific electronic instruments used in the lab and a circuit schematic are shown on the remote PC monitor. The student can manipulate the knobs on each instrument and make measurements at various points on the schematic. An example of a remote lab is an operational amplifier configured as Butterworth low pass filter. The student has complete control of the plus and minus power supplies and can verify the supply settings by connecting a digital multimeter to the power supply pins on the opamp. The frequency, offset and wave form of the input function generator can be controlled by the remote student. Channels 1 and 2 on the oscilloscope can be connected to any point on the circuit by the student using mouse clicks. The oscilloscope horizontal time base, the vertical volts/division, vertical position, trigger source and level, and the AC/DC/Gnd switches are all remotely controllable.
Light microscopic examination of the mast cell distribution in various oral tissues in germ-free and conventional beagle dogs revealed no differences between the two animals. Mast cells were observed ...in all tissues examined, with an increasing order of incidence as follows: cervical lymph node, parotid and submandibular glands, marginal gingivae, buccal mucosa and the middle one-third of the tongue. All four types (round, oval, elongated, and pseudopodial) of mast cells cell shapes previously described in the literature were observed. The marginal gingivae associated with the mandibular, second bicuspids was examined by light microscopy and was classified as to degree of inflammatory involvement. In a comparison of germ-free and conventional animals, the distribution of the degree of inflammation proved to be random. Correlation between mast cell densities and the degree of inflammatory infiltration was not statistically significant. However, mast cells tended to decrease as the inflammation became more severe. Electron microscopic examination of mast cells in the buccal mucosa revealed no difference in morphology of cells from germ-free or conventional animals. Cytoplasmic granules were of two basic types, one exhibited an amorphous matrix of uniform density and the other consisted of laminated coils of various sizes and densities.
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