The effects of syllable structure on diadochokinetic and reading rates.

Paragraphs with controlled phonetic structures were matched to similarly structured diadochokinetic (Maximum Repetition Rate) tasks in an effort to devise a more valid measurement for (1) assessing possible relationships between diadochokinesis and speech rate, and (2) evaluating the effects on articulation rates of such structural variables as number of consonants in a syllable, and alternating versus simple syllable repetitions. Highly stable results were obtained, suggesting the possibility of a sharp neurophysiological or biomechanical barrier which varies markedly among presumably normal speakers. Maximum repetition rates were poor predictors of normal reading rate performance.

Intracellular and intraluminal aspects of renal calculosis in the marine mollusc Macrocallista nimbosa.

The intracellular and intraluminal development of renal calculi in the bivalved mollusc Macrocallista nimbosa was investigated by histologic techniques. The origin of calculi is within the renal tubule cell. Early events involve the formation of a stone precursor into which are incorporated calcium salts, heavy metals, and mucopolysaccharides.

Analysis of renal calculi from a marine mollusc (Marcocallista nimbosa). Implications for the study of urolithiasis.

An X-ray diffraction analysis of kidney stones from the bivalved mollusc Macrocallista nimbosa has revealed the calculi composition to be amorhpous calcium phosphate. The use of this animal for the study of urolithiasis is suggested because of the spatial and temporal ubiquity of its renal calculi.

Repetitively pulsed, tunable ruby laser with solid etalon mode control.

A repetitively pulsed, tunable ruby laser has been designed and constructed as a light source for high resolution absorption spectroscopy and selective photochemical excitation. The frequency is tuned over a range of approximately 20 cm(-1) by changing the temperature of the ruby. The use of a solid sapphire etalon for mode control results in linewidth and stability within 0.

Selective Laser Photocatalysis of Bromine Reactions: Laser light excites gaseous bromine molecules to single bound quantum states near the dissociation continuum.

The results have shown that selective excitation obtained with a tunable monochromatic laser is a useful technique for studying photochemical and energy transfer processes. A new phenomenon in the photochemistry of bromine was observed, in which bound excited molecules, and not atoms, were formed in the primary process. The mechanism of the subsequent reaction consists of collisional dissociation of the excited molecules into atoms, which then initiated free-radical chains.