Lossless compression of image data products on th e FIFE CD-ROM series

How do you store enough of the key data sets, from a total of 120 gigabytes of data collected for a scientific experiment, on a collection of CD-ROM's, small enough to distribute to a broad scientific community? In such an application where information loss in unacceptable, lossless compression algorithms are the only choice. Although lossy compression algorithms can provide an order of magnitude improvement in compression ratios over lossless algorithms the information that is lost is often part of the key scientific precision of the data. Therefore, lossless compression algorithms are and will continue to be extremely important in minimizing archiving storage requirements and distribution of large earth and space (ESS) data sets while preserving the essential scientific precision of the data

TB Screening Guidelines for Transitional Care Unit

The basis of this research was the formation of new TB screening and risk assessment guidelines on a Transitional Care Unit within a medical center. Current evidence-based research studies helped to guide the recommendations for the policy changes based on their results and findings. The most pertinent policy changes are the treatment offered for patients suspected with HIV, the rigorous use of the Risk Assessment Tool, and BAMT testing for TB

Chloride to the rescue

© 2019 Newcomer. On the fiftieth anniversary of the discovery of the Ser-His-Asp catalytic triad, perhaps the most unusual variation on the textbook classic is described: An incomplete catalytic triad in a hydrolase is rescued by a chloride ion (Fig. 1). Structural and functional data provide compelling evidence that the active site of a phospholipase from Vibrio vulnificus employs the anion in place of the commonly observed Asp, reminding us that even well-trodden scientific ground has surprises in store

Structure of the epididymal retinoic acid binding protein at 2.1 Å resolution

Background: Androgen-dependent proteins in the lumen of the epididymis are required for sperm maturation. One of these is a retinoic acid binding protein, E-RABP, which binds both all-trans and 9-cis retinoic acid. The other retinoid-binding proteins whose structures are known do not bind 9-cis retinoids. Results: We describe the X-ray structure determination of E-RABP with and without bound ligand. The ligand binds deep in the β-barrel of the protein, the β-ionone ring innermost. The binding site, like the ligand, is amphipathic and the deepest part of the cavity is formed by a ring of aromatic amino acids. The isoprene tail of all-trans retinoic acid is bound in a folded conformation which resembles that of the 9-cis isomer. Conclusion: E-RABP achieves high-affinity binding of both all-trans and 9-cis isomers of retinoic acid by forcing the all-trans form to bind in a folded conformation. The RAR family of nuclear receptors for retinoic acid also binds both isomers, and their binding sites may therefore be similar. © 1993

Endogenous retinoids in rat epididymal tissue and rat and human spermatozoa

Recent work has demonstrated high levels of retinoid binding proteins in rat epididymis, and a lumenal retinoic acid binding protein has been purified. These findings suggested that vitamin A may be involved in spermatozoal maturation in the epididymis. We further addressed this question by quantifying retinol, retinyl esters, and retinoic acid isomers from perfused epididymal tissue, from rat testicular and epididymal spermatozoa, and from human ejaculate sperm. HPLC showed vitamin A levels to be higher in caput than in corpus or cauda tissue. Retinoic acid and 9-cis-retinoic acid were found to be graded from lowest levels in caput to highest in cauda. Spermatozoa from caput epididymidis and enriched testicular spermatozoa were found to have higher levels of vitamin A than did spermatozoa from corpus or cauda epididymidis. Spermatozoal retinyl esters had acyl substituents similar to those seen in whole epididymis, and diminished in quantity in sperm from distal segments. Human ejaculate sperm were found to retain high levels of retinyl palmitate and stearate. Retinol and retinoic acid were only marginally detectable in human sperm. Retention of retinoids in mature spermatozoa suggests roles for vitamin A in spermatozoal reproductive physiology beyond the epididymal stage