Comparative analysis of ribonuclease P RNA using gene sequences from natural microbial populations reveals tertiary structural elements.

PCR amplification of template DNAs extracted from mixed, naturally occurring microbial populations, using oligonucleotide primers complementary to highly conserved sequences, was used to obtain a large collection of diverse RNase P RNA-encoding genes. An alignment of these sequences was used in a comparative analysis of RNase P RNA secondary and tertiary structure. The new sequences confirm the secondary structure model based on sequences from cultivated organisms (with minor alterations in helices P12 and P18), providing additional support for nearly every base pair. Analysis of sequence covariation using the entire RNase P RNA data set reveals elements of tertiary structure in the RNA; the third nucleotides (underlined) of the GNRA tetraloops L14 and L18 are seen to interact with adjacent Watson-Crick base pairs in helix P8, forming A:G/C or G:A/U base triples. These experiments demonstrate one way in which the enormous diversity of natural microbial populations can be used to elucidate molecular structure through comparative analysis.

Characterization of spatial–temporal patterns in dynamic speckle sequences using principal component analysis

Abstract. Speckle is being used as a characterization tool for the analysis of the dynamics of slow-varying phenomena occurring in biological and industrial samples at the surface or near-surface regions. The retrieved data take the form of a sequence of speckle images. These images contain information about the inner dynamics of the biological or physical process taking place in the sample. Principal component analysis (PCA) is able to split the original data set into a collection of classes. These classes are related to processes showing different dynamics. In addition, statistical descriptors of speckle images are used to retrieve information on the characteristics of the sample. These statistical descriptors can be calculated in almost real time and provide a fast monitoring of the sample. On the other hand, PCA requires a longer computation time, but the results contain more information related to spatial–temporal patterns associated to the process under analysis. This contribution merges both descriptions and uses PCA as a preprocessing tool to obtain a collection of filtered images, where statistical descriptors are evaluated on each of them. The method applies to slow-varying biological and industrial processes.

Deformable templates for tracking and analysis of intravascular ultrasound sequences

Deformable Template models are first applied to track the inner wall of coronary arteries in intravascular ultrasound sequences, mainly in the assistance to angioplasty surgery. A circular template is used for initializing an elliptical deformable model to track wall deformation when inflating a balloon placed at the tip of the catheter. We define a new energy function for driving the behavior of the template and we test its robustness both in real and synthetic images. Finally we introduce a framework for learning and recognizing spatio-temporal geometric constraints based on Principal Component Analysis (eigenconstraints).

DuPont/Oberlin microfiltration technology : applications analysis report.

Mode of access: Internet.

Analysis of federal stimuli to development of new technology by suppliers to automobile manufacturers. An exploratory study of barriers and facilitators. Final report.

National Highway Traffic Safety Administration, Office of Research and Development, Washington, D.C.

Gas and fuel analysis for engineers; a compend for those interested in the economical application of fuel, prepared especially for the use of students at the Massachusetts institute of technology,

"References" at the end of some of the chapters.

Ultrox International ultraviolet radiation/oxidation technology : applications analysis report.

Mode of access: Internet.

Innovative concepts and technology for railroad-highway grade crossing motorist warning systems. Vol. I: overview and concept generation and analysis. Final report.

Transportation Systems Center, Cambridge, Mass.

Innovative concepts and technology for railroad-highway grade crossing motorist warning systems. Vol. II: the generation and analysis of alternative concepts. Final report.

Transportation Systems Center, Cambridge, Mass.

Economic system analysis of coal preconversion technology /

Prepared for Office of Coal Research, U.S. Department of the Interior.

Technology of textile design : a practical treatise on the construction and application of weaves for all textile fabrics and the analysis of cloth : containing also an appendix describing all the latest methods and improvements in designing and manufacturing : for the use of students, operatives, overseers, designers, mill managers, commission merchants and manufacturers /

Mode of access: Internet.

A study of matrix analysis methods for inelastic structures. Project no. 1467, Task no. 146701, prepared under Contract no. AF 33 (657)-8717 by Massachusetts Institute of Technology, Aeroelastic and Structures Research Laboratory.

Cover title.

Implementation of P.L. 96-480 Stevenson-Wydler Technology Innovation Act of 1980 [microform] : hearings (including an analysis of the hearings prepared for the subcommittee by the Congressional Research Service) before the Subcommittee on Science, Research, and Technology of the Committee on Science and Technology, U.S. House of Representatives, Ninety-seventh Congress, first session, July 14, 15, 16, 1981.

"No. 81."