634 research outputs found
Knowledge Networks, the Internet and, Development
Information and Communications Technologies (ICTs) are playing a significant role in
economic, political and cultural development. The relationship between technologies
supporting information processing and distribution, and the application of that knowledge
for development purposes has only recently come into focus. The discovery, publication
and application of new knowledge, the dissemination of information concerning best
practices and the exchange of views and opinions are now considered essential elements
of development work. These functions it is now increasingly recognized, are effectively
facilitated by ICTs. In the area of economic development ICTs can create new jobs, new
industry and service sector opportunities and a more educated work force. They make
possible the cross-border flow of information, promote international trade, particularly
high technology, bits rather than atoms, type trade and help to attract foreign direct
investment. ICTs can also contribute to political development by fostering good
governance and streamlining bureaucratic procedures through intra-governmental
networking. The creative use of ICTs, particularly the Internet, in the areas of health care,
education, environmental protection and in other developmentally important fields can
substantially contribute to the advancement of developing societies
Proton Quest: A Biotech Group
Abstract included in text
Vibration-tolerant narrow-linewidth semiconductor disk laser using novel frequency-stabilisation schemes
This paper will present developments in narrow-linewidth semiconductor-disk-laser systems using novel frequency-stabilisation schemes for reduced sensitivity to mechanical vibrations, a critical requirement for mobile applications. Narrow-linewidth single-frequency lasers are required for a range of applications including metrology and high-resolution spectroscopy. Stabilisation of the laser was achieved using a monolithic fibre-optic ring resonator with free spectral range of 181 MHz and finesse of 52 to act as passive reference cavity for the laser. Such a cavity can operate over a broad wavelength range and is immune to a wide band of vibrational frequency noise due to its monolithic implementation. The frequency noise of the locked system has been measured and compared to typical Fabry-Perot-locked lasers using vibration equipment to simulate harsh environments, and analysed here. Locked linewidths of < 40 kHz have been achieved. These developments offer a portable, narrow-linewidth laser system for harsh environments that can be flexibly designed for a range of applications
Comprehensive Investigation of the Caveolin 2 Gene: Resequencing and Association for Kidney Transplant Outcomes
Caveolae are plasma membrane structures formed from a complex of the proteins caveolin-1 and caveolin-2. Caveolae interact with pro-inflammatory cytokines and are dysregulated in fibrotic disease. Although caveolae are present infrequently in healthy kidneys, they are abundant during kidney injury. An association has been identified between a CAV1 gene variant and long term kidney transplant survival. Chronic, gradual decline in transplant function is a persistent problem in kidney transplantation. The aetiology of this is diverse but fibrosis within the transplanted organ is the common end point. This study is the first to investigate the association of CAV2 gene variants with kidney transplant outcomes. Genomic DNA from donors and recipients of 575 kidney transplants performed in Belfast was investigated for common variation in CAV2 using a tag SNP approach. The CAV2 SNP rs13221869 was nominally significant for kidney transplant failure. Validation was sought in an independent group of kidney transplant donors and recipients from Dublin, Ireland using a second genotyping technology. Due to the unexpected absence of rs13221869 from this cohort, the CAV2 gene was resequenced. One novel SNP and a novel insertion/deletion in CAV2 were identified; rs13221869 is located in a repetitive region and was not a true variant in resequenced populations. CAV2 is a plausible candidate gene for association with kidney transplant outcomes given its proximity to CAV1 and its role in attenuating fibrosis. This study does not support an association between CAV2 variation and kidney transplant survival. Further analysis of CAV2 should be undertaken with an awareness of the sequence complexities and genetic variants highlighted by this study
Quinolone signaling in the cell-to-cell communication system of Pseudomonas aeruginosa
Numerous species of bacteria use an elegant
regulatory mechanism known as quorum sensing to control
the expression of specific genes in a cell-density dependent
manner. In Gram-negative bacteria, quorum sensing systems
function through a cell-to-cell signal molecule (autoinducer)
that consists of a homoserine lactone with a fatty acid side
chain. Such is the case in the opportunistic human pathogen
Pseudomonas aeruginosa, which contains two quorum sensing
systems (las and rhl) that operate via the autoinducers,
N-(3-oxododecanoyl)-L-homoserine lactone and N-butyryl-Lhomoserine
lactone. The study of these signal molecules has
shown that they bind to and activate transcriptional activator
proteins that specifically induce numerous P. aeruginosa
virulence genes. We report here that P. aeruginosa produces
another signal molecule, 2-heptyl-3-hydroxy-4-quinolone,
which has been designated as the Pseudomonas quinolone
signal. It was found that this unique cell-to-cell signal controlled
the expression of lasB, which encodes for the major
virulence factor, LasB elastase. We also show that the synthesis
and bioactivity of Pseudomonas quinolone signal were
mediated by the P. aeruginosa las and rhl quorum sensing
systems, respectively. The demonstration that 2-heptyl-3-
hydroxy-4-quinolone can function as an intercellular signal
sheds light on the role of secondary metabolites and shows
that P. aeruginosa cell-to-cell signaling is not restricted to
acyl-homoserine lactones. Originally published Proc. Natl. Acad. Sci, Vol. 96, No. 20, Sep. 199
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