Substitution of Two Active‐Site Residues Alters C9‐Hydroxylation in a Class II Diterpene Synthase

Diterpenes form a vast and diverse class of natural products of both ecological and economic importance. Class II diterpene synthase (diTPS) enzymes control the committed biosynthetic reactions underlying diterpene chemical diversity. Homology modelling with site‐directed mutagenesis identified two active‐site residues in the horehound (Marrubium vulgare) class II diTPS peregrinol diphosphate synthase (MvCPS1); residue substitutions abolished the unique MvCPS1‐catalysed water‐capture reaction at C9 and redirected enzyme activity toward formation of an alternative product, halima‐5(10),13‐dienyl diphosphate. These findings contributed new insight into the steric interactions that govern diTPS‐catalysed regiospecific oxygenation reactions and highlight the feasibility of diTPS engineering to provide a broader spectrum of bioactive diterpene natural products.     

QSNET/sup II/: defining high-performance network design

QSNET/sup II/ optimizes interprocessor communication in systems built from standard server building blocks. Its short-message processing unit permits fast injection of small messages, providing ultra-low latency and scalability to thousands of nodes. Thus, in a sense, the high-performance network in a cluster computer is the computer because it largely defines achievable performance, widening the range of the applications a cluster can efficiently execute, as well as defining its scalability, fault tolerance, system software, and overall usability.     

Introducing wavelets and time--frequency analysis

The wavelet transform has emerged over recent years as a powerful time--frequency analysis and signal-coding tool suitable for use in the manipulation of complex nonstationary signals, and it has been in the forefront of many recent developments in biomedical and biological signal processing.     

Virtualized architectural heritage: new tools and techniques

Technology has come a long way in solving many of the early limitations of virtual reality (VR) and virtual worlds have quietly found growing acceptance in selected areas. However, issues of graphic quality and speed has dogged virtual world heritage developers, forcing simplistic representations and triggering criticism from the heritage community. In addition, until recently there was also a lack of inexpensive software and data standards (such as QuickTimeVR and Virtual Reality Modeling Language, or VRML) for creating visually realistic interactive environments. Although significant advances have been made, the accurate virtual representation of historic and cultural landmarks has been limited by a lack of tools to quickly, inexpensively, and accurately model reality. The representation of built heritage requires two distinct forms of 3D data, current, real-world conditions and virtual or theorized historical interpretations. We call the combination of the two forms virtualized as opposed to virtual. Despite the use of numerous measurement technologies in traditional heritage work, existing tools lacked the optimal mix of features required for virtualized architectural environments. Dissatisfied with available choices. We began an extensive analysis of available technologies. In this article, we review results in heritage projects with two emerging systems     

Intratumoral coinjection of adenoviral vectors expressing IL-2 and IL-12 results in enhanced frequency of regression of injected and untreated distal tumors

We have studied the ability of adenoviral (Ad) vectors expressing the cytokines IL-2 or IL-12 to mediate regression of established tumors in a mouse model of mammary adenocarcinoma. Previous results indicated that intratumoral injection of vectors expressing IL-2 (AdCAIL-2), or IL-12 (AdmIL-12.1) induced complete tumor regression in approximately 30-40% of treated animals. In the current studies, we investigated the mechanism of tumor killing in responding animals and the efficacy of AdIL-2 and AdIL-12 vector administration in combination compared with the use of either vector alone. Animals bearing subcutaneous mammary tumors were injected intratumorally with Ad vectors expressing IL-2 or IL-12 or were coinjected with both vectors. Animals receiving the combination treatment responded substantially better than animals which had received either vector alone, with 65% of animals treated with both vectors undergoing complete tumor regression. In all three treatment regimens, tumor regression was associated with the presence of specific antitumor antigen cytotoxic T-lymphocytes (CTLs), which secreted elevated levels of IFN-gamma. Consistent with circulating CTLs being involved in regression, when animals bearing bilateral tumors were inoculated in a single tumor with IL-2 or IL-12 expressing vectors, both tumors regressed in many cases. Again, treatment with both AdCAIL-2 and AdmIL-12.1 was most effective, with 63% of animals undergoing complete regression of both treated and untreated tumors, compared to 18 or 22% of animals injected with either AdCAIL-2 or AdmIL-12.1 alone. These data indicate that the combination of IL-2 and IL-12 is a more effective inducer of antitumor immune responses than either one alone, and that the resulting antitumor responses are effective in mediating the regression of distal untreated tumors, a property which may aid in the treatment of metastatic disease.     

Merkel cell carcinoma of the eyelid

The different methods that are available for the assessment and quantification of "brittle nails" and for the evaluation of various therapeutical approaches are compared. At this time, measurement of the swelling properties is the best documented and most reliable method for studying the treatment of brittle nails. Reliable qualitative data can also be obtained by scanning electron microscopy. Measurement of the transonychial water loss and assessment of thickness and density of nails by ultrasound have also been used successfully, but the methodology still has to be improved and the reproducibility, confirmed.     

Behavior of DDT,polychlorinated biphenyls (PCBs), and dieldrin at various stages of refining of marine oils for edible use

Two 300-lb batches of Eastern Canadian herring (Clupea harengus) oil were subjected to pilot plant processing to margarine stock for edible use. Samples were taken at various stages during processing for analysis of residues of the insecticide DDT and its metabolites DDD and DDE, of polychlorinated biphenyls (PCBs) and of dieldrin. Residue concentrations in the oil were not affected by degumming (phosphoric acid wash), alkali refining, or bleaching with activated earth. DDT and dieldrin were readily and completely destroyed by commercial hydrogenation over Ni catalyst, and DDD was largely removed at the same time. DDE and PCBs were partially reduced during hydrogenation in the one run in which DDD was completely removed, but were unaffected in another run, in which DDD was only partially removed. Deodorization of the oil with steam and vacuum effectively removed those residues which survived hydrogenation. Analysis of the Ni catalyst before and after hydrogenation showed that removal of residues during hydrogenation was not due to their adsorption to the catalyst, but was more probably due to metal-catalyzed degradation to unidentified products. Deodorizer condensates showed only a slight enrichment in residue levels over those found in the oil.     

Emerging trends in virtual heritage

From the pyramids at Giza to Kakadu National Park in Australia, the world's cultural and natural heritage has stood the test of time. The pace of progress threatens these landmarks of our past at an ever-increasing pace. Rapid advances in digital technologies in recent years, from new media to virtual reality (VR) and high-speed networks, have offered heritage some hope. The first wave of VR worlds failed to live up to the promise. Today, the forward march of technology has quietly enabled a second wave of VR applications. Digital tools and techniques offer new hope to the often painstakingly complex tasks of archaeology, surveying, historic research, conservation, and education. These emerging second-generation technologies can be grouped into three domains: 3D documentation (everything from site surveys to epigraphy), 3D representation (from historic reconstruction to visualization), and 3D dissemination (from immersive networked worlds to “in situ” augmented reality). The author reviews these emerging trends     

Exceptional occurrence of odd-chain fatty acids in smelt (Osmerus mordax) from Jeddore Harbour,Nova Scotia

The fatty acid composition of smelt,Osmerus mordax, from several areas in Eastern Canada is reported. Smelt from Jeddore Harbour, N.S., were unusual in having up to 10% of C₁₅, C₁₇ and C₁₉ acids. These acids were similar in structure to odd-chain acids occurring in other marine lipids, notably mullet, and were distributed among all body and gonad lipids. Possible reasons for their occurrence are discussed.     

POSITIONAL AND SEQUENTIAL PROBES IN SERIAL LEARNING.

24 COLLEGE MALES PARTICIPATED IN 2 EXPERIMENTS WHICH USED A SHORT-TERM MEMORY TASK AND 3 TYPES OF PROBE TESTS. IN EXP. I, DESIGNED TO DISCOVER IF POSITIONAL CUES ARE MORE EFFECTIVE THAN SEQUENTIAL CUES IN SERIAL LIST LEARNING, EACH LIST WAS SEEN ONCE AND FOLLOWED BY A SINGLE PROBE TEST FOR A SINGLE ITEM. SERIAL POSITION CURVES SHOWED THAT THE POSITIONAL PROBE LED TO SOMEWHAT HIGHER RECALL OF ITEMS OCCUPYING THE END POSITIONS OF A LIST THAN THE SEQUENTIAL PROBE. EXP. II WAS UNDERTAKEN TO MAXIMIZE THE EFFECTIVENESS OF THE POSITION PROBE. 5 TRIALS WERE GIVEN BEFORE A RECALL TEST. SERIAL POSITION CURVES FOR THE 3 TYPES OF PROBES SHOWED THAT THE DIFFERENCES BETWEEN THEM WERE NOT SIGNIFICANT. THE OVER-ALL RESULTS WERE INTERPRETED AS INDICATING THAT POSITIONAL CUES AND SEQUENTIAL CUES MAY BE EQUALLY EFFECTIVE IN SERIAL LEARNING. (FRENCH SUMMARY) (PsycINFO Database Record (c) 2010 APA, all rights reserved)