Development of non-weak link bulk YBCO grain boundaries for high magnetic field eegimeering applications

A non-weak link joining technique has been developed for YBCO pseudo-crystals fabricated by seeded peritectic solidification based on the formation of a liquid phase which segregates from the platelet boundaries at temperatures above = 920 °C. Electrical and magnetic measurements on these boundaries suggest that their irreversibility field can be as high as 7 T at 77 K in fully oxygenated pseudo-crystals joined along their crystallographic ab-planes which is comparable to the irreversibility behaviour of the adjacent YBCO grains. © 1999 IEEE.

Molecular characterization of a weak fibrinogen-clotting enzyme from Trimeresurus jerdonii venom

A fibrinogen-clotting enzyme designed as jerdonobin-II was isolated from the venom of Trimeresurus jerdonii. It differed in molecular weight and N-terminal sequence with the previously isolated jerdonobin, a thrombin-like enzyme from the same venom. The enzyme consists of a single polypeptide chain with molecular weights of 30,000 and 32,000 under non-reducing and reducing conditions, respectively. Jerdonobin-II showed weak fibrinogen clotting activity and its activity unit on fibrinogen was calculated to be less than one unit using human thrombin as standard. The precursor protein sequence of jerodonobin-II was deduced from cloned cDNA sequence. The sequence shows high similarity (identity = 89%) to TSV-PA, a specific plasminogen activator from venom of T stejnegeri. Despite of the sequence similarity, jerdonobin-II was found devoid of plasminogen activating effect. Sequence alignment analysis suggested that the replacement of Lys(239) in TSV-PA to Gln(239) in jerdonobin-II might play an important role on their plasminogen activating activity difference. (C) 2005 Elsevier Ltd. All rights reserved.

Indole and carbazole alkaloids from Glycosmis montana with weak anti-HIV and cytotoxic activities

A diprenylated indole, (E)-3-(3-hydroxymethyl-2-butenyl)-7-(3-methyl-2-butenyl)-1H-indole (1), and six known carbazole alkaloids were isolated from the twigs and leaves of Glycosmis montana Pierre (Rutaceae). Their structures were determined on the basis of analysis of spectral evidence including 1D and 2D NMR and MS. The alkaloids (1-3) exhibited weak to moderate take in vitro inhibitory activity against HIV replication in C8166 cells, and they (as well as carbalexine A and B) had cytotoxic activity against the human leukaemia cell line CCRF-CEM. (c) 2005 Elsevier Ltd. All rights reserved.

Network structure preserving model reduction with weak a priori structural information

This paper extends a state projection method for structure preserving model reduction to situations where only a weaker notion of system structure is available. This weaker notion of structure, identifying the causal relationship between manifest variables of the system, is especially relevant is settings such as systems biology, where a clear partition of state variables into distinct subsystems may be unknown, or not even exist. The resulting technique, like similar approaches, does not provide theoretical performance guarantees, so an extensive computational study is conducted, and it is observed to work fairly well in practice. Moreover, conditions characterizing structurally minimal realizations and sufficient conditions characterizing edge loss resulting from the reduction process, are presented. ©2009 IEEE.

Achieving robust face recognition from video by combining a weak photometric model and a learnt generic face invariant

In spite of over two decades of intense research, illumination and pose invariance remain prohibitively challenging aspects of face recognition for most practical applications. The objective of this work is to recognize faces using video sequences both for training and recognition input, in a realistic, unconstrained setup in which lighting, pose and user motion pattern have a wide variability and face images are of low resolution. The central contribution is an illumination invariant, which we show to be suitable for recognition from video of loosely constrained head motion. In particular there are three contributions: (i) we show how a photometric model of image formation can be combined with a statistical model of generic face appearance variation to exploit the proposed invariant and generalize in the presence of extreme illumination changes; (ii) we introduce a video sequence re-illumination algorithm to achieve fine alignment of two video sequences; and (iii) we use the smoothness of geodesically local appearance manifold structure and a robust same-identity likelihood to achieve robustness to unseen head poses. We describe a fully automatic recognition system based on the proposed method and an extensive evaluation on 323 individuals and 1474 video sequences with extreme illumination, pose and head motion variation. Our system consistently achieved a nearly perfect recognition rate (over 99.7% on all four databases). © 2012 Elsevier Ltd All rights reserved.