New alkaloids from the indopacific sponge Stylissa carteri

Two samples of the marine sponge Stylissa carteri collected in Indonesia yielded two new bromopyrrole alkaloids: debromostevensine (1) and debromohymenin (2), as well as nine other known congeners (3-11). The structures of the new compounds were unambiguously established on the basis of their NMR and mass spectra.     

Use of a non-rigid region in T4 lysozyme to design an adaptable metal-binding site

It is not easy to find candidate sites within a given proteinwhere the geometry of the polypeptide chain matches that ofmetal-binding sites in known protein structures. By choosinga location in T4 lysozyme that is inherently flexible, it waspossible to engineer a two-histidine site that binds differentdivalent cations. Crystallographic analysis shows that the geometryof binding of zinc is distorted tetrahedral while that of cobaltand nickel is octahedral. Insofar as spectroscopic data canbe measured, they indicate that similar modes of coordinationare retained in solution. The two substitutions, Thr21     

Compassion Practicum: A Capstone Design Experience at the United States Military Academy

A partnership has been developed linking the United States Military Academy and Special People in the Northeast, a non-profit agency for the mentally and physically handicapped children and adults based in Philadelphia. The present work documents a student design team's design and construction of a ticket-tearing device for a young man in the advanced stages of cerebral palsy and concludes with an evaluation of the entire process.     

20—DYNAMIC FORCES IN WEFT-KNITTING: PART I: A COMPARISON OF MEASURED NON-KNITTING CAM FORCES WITH MATHEMATICALLY PREDICTED VALUES

Non-knitting cam forces are the dynamic forces between the knitting cams and the latch needle when the needle passes down the stitch cam and along the guard cam but does not draw a yarn loop. Good agreement is shown between theoretical predictions of the forces and the experimental measurement of them.     

20—THE ASSESSMENT OF SMALL-SAMPLE IRREGULARITY TRACES

Eight methods of determining the coefficient of variation of yarns or slivers when only a limited amount of material is available are discussed. The basic method involves direct measurement and calculation, and each of the other methods is compared with this one, which tends to be somewhat lengthy, for a range of man-made-fibre yams spun on the cotton system. A method based on the use of the cumulative-frequency distribution is shown to be quite the most accurate of the seven methods investigated and has the merit that it can be performed comparatively rapidly.     

22—DYNAMIC FORCES IN WEFT-KNITTING PART III: YARN TENSIONS DURING THE LOOP-FORMING PROCESS

Measurements are reported of the yarn tensions arising during the knitted-loop-formation process. An approximate method for the analysis of yarn tension is demonstrated, and the theoretical results derived from this are compared with experimental results. Reasonably close agreement is observed, although the method of analysis is sensitive to small errors.     

Characterization of low-light-level cameras for digitized video microscopy

The use of low-light-level video cameras and solid-state image detectors in conjunction with image digitizers for optical microscopy is increasing dramatically as more people learn about such systems, and as they become more powerful, less expensive, and easier to use. However, there is currently little information available allowing comparison between cameras, or for determining camera suitability for a given experiment. In this paper, we describe a series of tests designed to characterize the performance of low-light-level cameras. The results of these tests should assist in the selection of appropriate cameras for given video microscopy applications.     

SoftUDC: a software-based data center for utility computing

Utility computing aims to aggregate server, network, and storage systems into a single, centrally managed pool of resources. SoftUDC, a virtual machine monitor, lets applications and administrative domains share physical resources while maintaining full functional isolation.