Supramolecular parallel beta-sheet and amyloid-like fibril forming peptides using delta-aminovaleric acid residue

Four terminally blocked tripeptides containing delta-aminovaleric acid residue self-assemble to form supramolecular beta-sheet structures as are revealed from their FT-IR data. Single crystal X-ray diffraction studies of two representative peptides also show that they form parallel beta-sheet structures. Self-aggregation of these beta-sheet forming peptides leads to the formation of fibrillar structures, as is evident from scanning electron microscopic (SEM) and transmission electron microscopic (TEM) images. These peptide fibrils bind to a physiological dye, Congo red and exhibit a typical green-gold birefringence under polarized light, showing close resemblance to neurodegenerative disease causing amyloid fibrils. (c) 2005 Elsevier Ltd. All rights reserved.

Studies on the parallel synthesis and evaluation of new heterocyclic extractants for the partitioning of minor actinides

Multiple parallel synthesis and evaluation have been combined in order to identify new nitrogen heterocycles for the partitioning of minor actinides(III) such as americium(III) from lanthanides such as europium(Ill). An array of triazine-containing molecules was made using multiple parallel syntheses from diketones and amide hydrazides. An excess of each of the resulting purified reagents was dissolved in 1,1,2,2-tetrachloroethane containing 2-bromodecanoic acid, and equilibrated with an aqueous solution containing the radiotracers Eu-152 and Am-241 in nitric acid ([Eu] + [Am] < 400 nanomol dm(-3)). Gamma counting of the organic and aqueous phases led to the identification of several new reagents for the selective extraction of americium(III). In particular, 6-(2-pyridyl)-2-(5,6-dialkyl-1,2,4-triazaphenyl)pyridines were found to be effective reagents for the separation of americium(III) from europium(III), (SFAm/Eu was ca. 30 in [HNO3] = 0.013 mol/L).

2D parallel interpenetration of [M-2(bpp)(4)X-4] [M, Fe(II)/Co(II); bpp, 4,4 '-trimethylenedipyridine; X, SCN-SeCN- and N-3(-)] complexes: pseudohalide-dependent conformation of bpp

Three coordination complexes of Co(II)/Fe(II) with 4,4'-trimethylenedipyridine (bpp) and pseudohalides (SCN-, SeCN- and N-3(-)) have been synthesized. The complexes have been characterized by X-ray single crystal structure determination. They are isomorphous having 2D layers in which two independent wavy nets display parallel interwoven structures. Pseudohalide binds metal centers through N terminal and occupies the trans axial positions of the octahedral metal coordination environment. Pseudohalide remains pendant on both sides of the polymeric layer and help the stacking through hydrogen bonding. The conformation of bpp in the interpenetrated nets is observed to be dependent on the choice of pseudohalide. (C) 2008 Elsevier Inc. All rights reserved.

Giving up on modern foreign languages? Students' perceptions of learning French

This article reports on the findings of an investigation into the attitudes of English students aged 16 to 19 years towards French and how they view the reasons behind their level of achievement. Those students who attributed success to effort, high ability, and effective learning strategies had higher levels of achievement, and students intending to continue French after age 16 were more likely than noncontinuers to attribute success to these factors. Low ability and task difficulty were the main reasons cited for lack of achievement in French, whereas the possible role of learning strategies tended to be overlooked by students. It is argued that learners' self-concept and motivation might be enhanced through approaches that encourage learners to explore the causal links between the strategies they employ and their academic performance, thereby changing the attributions they make for success or failure.

The remote distractor effect in saccade programming: channel interactions and lateral inhibition

We explored the dependency of the saccadic remote distractor effect (RDE) on the spatial frequency content of target and distractor Gabor patches. A robust RDE was obtained with low-medium spatial frequency distractors, regardless of the spatial frequency of the tat-get. High spatial frequency distractors interfered to a similar extent when the target was of the same spatial frequency. We developed a quantitative model based on lateral inhibition within an oculomotor decision unit. This lateral inhibition mechanism cannot account for the interaction observed between target and distractor spatial frequency, pointing to the existence of channel interactions at an earlier level. (C) 2004 Elsevier Ltd. All rights reserved.

Parallel and distributed computing with Java

The Java language first came to public attention in 1995. Within a year, it was being speculated that Java may be a good language for parallel and distributed computing. Its core features, including being objected oriented and platform independence, as well as having built-in network support and threads, has encouraged this view. Today, Java is being used in almost every type of computer-based system, ranging from sensor networks to high performance computing platforms, and from enterprise applications through to complex research-based.simulations. In this paper the key features that make Java a good language for parallel and distributed computing are first discussed. Two Java-based middleware systems, namely MPJ Express, an MPI-like Java messaging system, and Tycho, a wide-area asynchronous messaging framework with an integrated virtual registry are then discussed. The paper concludes by highlighting the advantages of using Java as middleware to support distributed applications.

Hierarchical composite regular parallel architecture

The design space of emerging heterogenous multi-core architectures with re-configurability element makes it feasible to design mixed fine-grained and coarse-grained parallel architectures. This paper presents a hierarchical composite array design which extends the curret design space of regular array design by combining a sequence of transformations. This technique is applied to derive a new design of a pipelined parallel regular array with different dataflow between phases of computation.

Linear predicted two-pass hexagonal algorithm with parallel implementation for motion estimation

This paper presents a paralleled Two-Pass Hexagonal (TPA) algorithm constituted by Linear Hashtable Motion Estimation Algorithm (LHMEA) and Hexagonal Search (HEXBS) for motion estimation. In the TPA., Motion Vectors (MV) are generated from the first-pass LHMEA and are used as predictors for second-pass HEXBS motion estimation, which only searches a small number of Macroblocks (MBs). We introduced hashtable into video processing and completed parallel implementation. We propose and evaluate parallel implementations of the LHMEA of TPA on clusters of workstations for real time video compression. It discusses how parallel video coding on load balanced multiprocessor systems can help, especially on motion estimation. The effect of load balancing for improved performance is discussed. The performance or the algorithm is evaluated by using standard video sequences and the results are compared to current algorithms.

Two-pass hexagonal algorithm with parallel implementation for video coding

This paper presents a paralleled Two-Pass Hexagonal (TPA) algorithm constituted by Linear Hashtable Motion Estimation Algorithm (LHMEA) and Hexagonal Search (HEXBS) for motion estimation. In the TPA, Motion Vectors (MV) are generated from the first-pass LHMEA and are used as predictors for second-pass HEXBS motion estimation, which only searches a small number of Macroblocks (MBs). We introduced hashtable into video processing and completed parallel implementation. We propose and evaluate parallel implementations of the LHMEA of TPA on clusters of workstations for real time video compression. It discusses how parallel video coding on load balanced multiprocessor systems can help, especially on motion estimation. The effect of load balancing for improved performance is discussed. The performance of the algorithm is evaluated by using standard video sequences and the results are compared to current algorithms.

Improved two-pass hexagonal algorithm with parallel implementation for video coding - art. no. 60630J

This paper presents an improved parallel Two-Pass Hexagonal (TPA) algorithm constituted by Linear Hashtable Motion Estimation Algorithm (LHMEA) and Hexagonal Search (HEXBS) for motion estimation. Motion Vectors (MV) are generated from the first-pass LHMEA and used as predictors for second-pass HEXBS motion estimation, which only searches a small number of Macroblocks (MBs). We used bashtable into video processing and completed parallel implementation. The hashtable structure of LHMEA is improved compared to the original TPA and LHMEA. We propose and evaluate parallel implementations of the LHMEA of TPA on clusters of workstations for real time video compression. The implementation contains spatial and temporal approaches. The performance of the algorithm is evaluated by using standard video sequences and the results are compared to current algorithms.