University of Westminster

About: University of Westminster is a education organization based out in London, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 2944 authors who have published 8426 publications receiving 200236 citations. The organization is also known as: Westminster University & Royal Polytechnic Institution.

Cognitive and mood effects of 8 weeks' supplementation with 400 mg or 1000 mg of the omega-3 essential fatty acid docosahexaenoic acid (DHA) in healthy children aged 10-12 years.

Abstract: Introduction: Despite media and public expectation of efficacy, no study to date has investigated the cognitive and mood effects of omega 3 supplementation in healthy children. Subjects and methods: This randomised, double-blind, placebo-controlled, parallel groups pilot study assessed the cognitive and mood effects of either 400 mg or 1000 mg of docosahexaenoic acid (DHA) in 90 healthy children aged 10–12 years. Cognitive performance and mood was assessed prior to, and 8 weeks following, commencement of treatment. Results: There was a significant treatment effect on one cognitive measure (speed of word recognition), with the lower dose speeding, and the higher dose slowing, performance. Overall, the pattern of results strongly suggests that this effect was due to chance fluctuations in performance and that the treatments had no consistent or interpretable effect on performance. Conclusions: The results here do not suggest that supplementation with these doses of DHA for 8 weeks has any beneficia...

High-performance parallel programming in Java: exploiting native libraries

Abstract: With most of today's fast scientific software written in Fortran and C, Java has a lot of catching up to do. In this paper we discuss how new Java programs can capitalize on high-performance libraries for other languages. With the help of a tool we have automatically created Java bindings for several standard libraries: MPI, BLAS, BLACS, PBLAS and ScaLAPACK. The purpose of the additional software layer introduced by the bindings is to resolve the interface problems between different programming languages such as data type mapping, pointers, multidimensional arrays, etc. For evaluation, performance results are presented for Java versions of two benchmarks from the NPB and PARKBENCH suites on the IBM SP2 using JDK and IBM's high-performance Java compiler, and on the Fujitsu AP3000 using Toba - a Java-to-C translator. The results confirm that fast parallel computing in Java is indeed possible.

A quantitative real-time PCR assay for the identification and enumeration of Alexandrium cysts in marine sediments

Abstract: Harmful algal blooms (HABs) are a global problem that affects both human and ecosystem health. One of the most serious and widespread HAB poisoning syndromes is paralytic shellfish poisoning, commonly caused by Alexandrium spp. dinoflagellates. Like many toxic dinoflagellates, Alexandrium produces resistant resting cysts as part of its life cycle. These cysts play a key role in bloom initiation and decline, as well as dispersal and colonization of new areas. Information on cyst numbers and identity is essential for understanding and predicting blooms, yet comprehensive cyst surveys are extremely time- and labor-intensive. Here we describe the development and validation of a quantitative real-time PCR (qPCR) technique for the enumeration of cysts of A. tamarense of the toxic North American/Group I ribotype. The method uses a cloned fragment of the large subunit ribosomal RNA gene as a standard for cyst quantification, with an experimentally determined conversion factor of 28,402±6152 LSU ribosomal gene copies per cyst. Tests of DNA extraction and PCR efficiency show that mechanical breakage is required for adequate cyst lysis, and that it was necessary to dilute our DNA extracts 50-fold in order to abolish PCR inhibition from compounds co-extracted from the sediment. The resulting assay shows a linear response over 6 orders of magnitude and can reliably quantify ?10 cysts/cm3 sediment. For method validation, 129 natural sediment samples were split and analyzed in parallel, using both the qPCR and primulin-staining techniques. Overall, there is a significant correlation (p<0.001) between the cyst abundances determined by the two methods, although the qPCR counts tend to be lower than the primulin values. This underestimation is less pronounced in those samples collected from the top 1 cm of sediment, and more pronounced in those derived from the next 1–3 cm of the core. These differences may be due to the condition of the cysts in the different layers, as the top 1 cm contains more recent cysts while those in the next 1–3 cm may have been in the sediments for many years. Comparison of the cyst densities obtained by both methods shows that a majority (56.6%) of the values are within a two-fold range of each other and almost all of the samples (96.9%) are within an order of magnitude. Thus, the qPCR method described here represents a promising alternative to primulin-staining for the identification and enumeration of cysts. The qPCR method has a higher throughput, enabling the extraction and assay of 24 samples in the time required to process and count 8–10 samples by primulin-staining. Both methods require prior expertise, either in taxonomy or molecular biology. Fewer person-hours per sample are required for qPCR, but primulin-staining has lower reagent costs. The qPCR method might be more desirable for large-scale cyst mapping, where large numbers of samples are generated and a higher sample analysis rate is necessary. While the qPCR and primulin-staining methods generate similar data, the choice of counting method may be most influenced by the practical issue of the different relative costs of labor and materials between the two methods.