B mu G@Sbase - a microarray database and analysis tool

The manufacture and use of a whole-genome microarray is a complex process and it is essential that all data surrounding the process is stored, is accessible and can be easily associated with the data generated following hybridization and scanning. As part of a program funded by the Wellcome Trust, the Bacterial Microarray Group at St. George's Hospital Medical School (BμG@S) will generate whole-genome microarrays for 12 bacterial pathogens for use in collaboration with specialist research groups. BμG@S will collaborate with these groups at all levels, including the experimental design, methodology and analysis. In addition, we will provide informatic support in the form of a database system (BμG@Sbase). BμG@Sbase will provide access through a web interface to the microarray design data and will allow individual users to store their data in a searchable, secure manner. Tools developed by BμG@S in collaboration with specific research groups investigating analysis methodology will also be made available to those groups using the arrays and submitting data to BμG@Sbase

Analysis of low temperature trapping and recombination in II-VI compounds using photodielectric techniques

Using photodielectric effect to detect densities of free and trapped carriers in II-VI compounds at cryogenic temperature

Research on digital transducer principles. Volume 6 - The photodielectric effect in cadmium sulfide, 1 July 1967 - 30 June 1968

Cadmium sulfide photodielectric effect at cryogenic temperatures with bibliograph

A rhodanine agent active against non-replicating intracellular Mycobacterium avium subspecies paratuberculosis.

BACKGROUND: Antibiotic therapy targeting chronic mycobacterial disease is often ineffective due to problems with the emergence of drug resistance and non-replicating persistent intracellular antibiotic resistant phenotypes. Strategies which include agents able to enhance host cell killing mechanisms could represent an alternative to conventional methods with the potential for host clearance if active against dormant phenotypes. Investigations of agents with potential activity against non-replicating mycobacteria however are restricted due to a need for assays that can assess bacterial viability without having to culture. RESULTS: This study describes the development and use of a pre16S ribosomal gene RNA/DNA ratio viability assay which is independent of the need for culture, supported by a novel thin layer accelerated mycobacterial colony forming method for determining viability and culturability of MAP in intracellular environments. We describe the use of these tools to demonstrate intracellular killing activity of a novel rhodanine agent (D157070) against the intracellular pathogen Mycobacterium avium subspecies paratuberculosis (MAP) and show that the culturability of MAP decreases relative to its viability on intracellular entry suggesting the induction of a non-culturable phenotype. We further demonstrate that D157070, although having no direct activity against the culturability of extracellular MAP, can bind to cultured MAP cells and has significant influence on the MAP transcriptome, particularly with respect of delta(L )associated genes. D157070 is shown to be taken up by bovine and human cells and able to enhance host cell killing, as measured by significant decreases in both culturability and viability of intracellular MAP. CONCLUSIONS: This work suggests that pre16srRNA gene ratios represent a viable method for studying MAP viability. In addition, the rhodanine agent D157070 tested is non-toxic and enhances cell killing activity against both growing and latent MAP phenotypes

The affective quality of human-natural environment relationships

Using a psychometric methodology the present study explored the associations between natural environments and experiential feeling states. The effects of the frequency of participants‟ (N = 90) experience of the natural environment and of the location of their childhood upbringing were also investigated. Ten natural environments mapped on to an orthogonal two-component experiential structure labeled Eudemonia (ostensibly positive feelings) and Apprehension (ostensibly negative feelings). Generally, the more natural environments tended to be associated with higher eudemonia and higher apprehension, the less natural environments with both lower eudemonia and lower apprehension. In line with expectations, participants from rural childhood locations, compared with urban participants, reported less Apprehension and participants with greater experience of the natural environment, compared with participants with less experience, reported greater Eudemonia and less Apprehension. Results are discussed in relation to environmental experiences and affective psychological wellbeing

The pneumococcal response to oxidative stress includes a role for Rgg

Streptococcus pneumoniae resides in the oxygen-rich environment of the upper respiratory tract, and therefore the ability to survive in the presence of oxygen is an important aspect of its in vivo survival. To investigate how S. pneumoniae adapts to oxygen, we determined the global gene expression profile of the micro-organism in aerobiosis and anaerobiosis. It was found that exposure to aerobiosis elevated the expression of 54 genes, while the expression of 15 genes was downregulated. Notably there were significant changes in putative genome plasticity and hypothetical genes. In addition, increased expression of rgg, a putative transcriptional regulator, was detected. To test the role of Rgg in the pneumococcal oxidative stress response, an isogenic mutant was constructed. It was found that the mutant was sensitive to oxygen and paraquat, but not to H2O2. In addition, the absence of Rgg strongly reduced the biofilm-forming ability of an unencapsulated pneumococcus. Virulence studies showed that the median survival time of mice infected intranasally with the rgg mutant was significantly longer than that of the wild-type-infected group, and the animals infected with the mutant developed septicaemia later than those infected intranasally with the wild-type

Prospects for measuring the electric dipole moment of the electron using electrically trapped polar molecules

Heavy polar molecules can be used to measure the electric dipole moment of the electron, which is a sensitive probe of physics beyond the Standard Model. The value is determined by measuring the precession of the molecule's spin in a plane perpendicular to an applied electric field. The longer this precession evolves coherently, the higher the precision of the measurement. For molecules in a trap, this coherence time could be very long indeed. We evaluate the sensitivity of an experiment where neutral molecules are trapped electrically, and compare this to an equivalent measurement in a molecular beam. We consider the use of a Stark decelerator to load the trap from a supersonic source, and calculate the deceleration efficiency for YbF molecules in both strong-field seeking and weak-field seeking states. With a 1s holding time in the trap, the statistical sensitivity could be ten times higher than it is in the beam experiment, and this could improve by a further factor of five if the trap can be loaded from a source of larger emittance. We study some effects due to field inhomogeneity in the trap and find that rotation of the electric field direction, leading to an inhomogeneous geometric phase shift, is the primary obstacle to a sensitive trap-based measurement.Comment: 22 pages, 7 figures, prepared for Faraday Discussion 14

Improved surface quality of anisotropically etched silicon {111} planes for mm-scale integrated optics

We have studied the surface quality of millimeter-scale optical mirrors produced by etching CZ and FZ silicon wafers in potassium hydroxide to expose the $\{111\}$ planes. We find that the FZ surfaces have four times lower noise power at spatial frequencies up to $500\, {mm}^{-1}$. We conclude that mirrors made using FZ wafers have higher optical quality

Walking Through Jelly: Language Proficiency, Emotions, and Disrupted Collaboration in Global Work

In an ethnographic study comprised of interviews and concurrent observations of 145 globally distributed members of nine project teams of an organization, we found that uneven proficiency in English, the lingua franca, disrupted collaboration for both native and non-native speakers. Although all team members spoke English, different levels of fluency contributed to tensions on these teams. As non-native English speakers attempted to counter the apprehension they felt when having to speak English and native English speakers fought against feeling excluded and devalued, a cycle of negative emotion ensued and disrupted interpersonal relationships on these teams. We describe in detail how emotions and actions evolved recursively as coworkers sought to relieve themselves of negative emotions prompted by the lingua franca mandate and inadvertently behaved in ways that triggered negative responses in distant coworkers. Our results add to the scant literature on the role of emotions in collaborative relationships in organizations and suggest that organizational policies can set in motion a cycle of negative emotions that interfere with collaborative work.

Stochastic multi-channel lock-in detection

High-precision measurements benefit from lock-in detection of small signals. Here we discuss the extension of lock-in detection to many channels, using mutually orthogonal modulation waveforms, and show how the the choice of waveforms affects the information content of the signal. We also consider how well the detection scheme rejects noise, both random and correlated. We address the particular difficulty of rejecting a background drift that makes a reproducible offset in the output signal and we show how a systematic error can be avoided by changing the waveforms between runs and averaging over many runs. These advances made possible a recent measurement of the electron's electric dipole moment.Comment: 11 pages, 3 figure