DNA Renaturation at the Water-Phenol Interface

We study DNA adsorption and renaturation in a water-phenol two-phase system, with or without shaking. In very dilute solutions, single-stranded DNA is adsorbed at the interface in a salt-dependent manner. At high salt concentrations the adsorption is irreversible. The adsorption of the single-stranded DNA is specific to phenol and relies on stacking and hydrogen bonding. We establish the interfacial nature of a DNA renaturation at a high salt concentration. In the absence of shaking, this reaction involves an efficient surface diffusion of the single-stranded DNA chains. In the presence of a vigorous shaking, the bimolecular rate of the reaction exceeds the Smoluchowski limit for a three-dimensional diffusion-controlled reaction. DNA renaturation in these conditions is known as the Phenol Emulsion Reassociation Technique or PERT. Our results establish the interfacial nature of PERT. A comparison of this interfacial reaction with other approaches shows that PERT is the most efficient technique and reveals similarities between PERT and the renaturation performed by single-stranded nucleic acid binding proteins. Our results lead to a better understanding of the partitioning of nucleic acids in two-phase systems, and should help design improved extraction procedures for damaged nucleic acids. We present arguments in favor of a role of phenol and water-phenol interface in prebiotic chemistry. The most efficient renaturation reactions (in the presence of condensing agents or with PERT) occur in heterogeneous systems. This reveals the limitations of homogeneous approaches to the biochemistry of nucleic acids. We propose a heterogeneous approach to overcome the limitations of the homogeneous viewpoint

Erratum: Luminosity function, sizes and FR dichotomy of radio-loud AGN

This erratum corrects a number of formulae containing mistakes in the paper 'Luminosity function, sizes and FR dichotomy of radio-loud AGN', 2007, MNRAS, v. 381, p.1548. The corrections do not alter any of the conclusions in the original paper.Comment: single page, no figures, erratum to MNRAS, 2007, v. 381, p. 154

The promoter from SlREO, a highly-expressed, root-specific Solanum lycopersicum gene, directs expression to cortex of mature roots

Root-specific promoters are valuable tools for targeting transgene expression, but many of those already described have limitations to their general applicability. We present the expression characteristics of SlREO, a novel gene isolated from tomato (Solanum lycopersicum L.). This gene was highly expressed in roots but had a very low level of expression in aerial plant organs. A 2.4-kb region representing the SlREO promoter sequence was cloned upstream of the uidA GUS reporter gene and shown to direct expression in the root cortex. In mature, glasshouse-grown plants this strict root specificity was maintained. Furthermore, promoter activity was unaffected by dehydration or wounding stress but was somewhat suppressed by exposure to NaCl, salicylic acid and jasmonic acid. The predicted protein sequence of SlREO contains a domain found in enzymes of the 2-oxoglutarate and Fe(II)-dependent dioxygenase superfamily. The novel SlREO promoter has properties ideal for applications requiring strong and specific gene expression in the bulk of tomato root tissue growing in soil, and is also likely to be useful in other Solanaceous crop

Evaluation of the KA24 (Knowledge Access 24) service for health- and social-care staff in London and the south-east of England. Part 2: qualitative

AIMS AND OBJECTIVES: The aim of this two-part paper is to identify the main transferable lessons learned from both the quantitative and qualitative evaluations of the KA24 (Knowledge Access 24) service of online databases and selected full text journals for health and social care staff in London and the South-East of England. The objectives of the qualitative evaluation were to assess the enablers and barriers to usage, and to assess the impact of the service on patient care. METHODS: Telephone interviews (n=65) and a questionnaire survey (n=296) were conducted with various types of user, in various Trust settings. Some non-users were also contacted. Selection of interviewees and questionnaire recipients was not random, and aimed to cover all groups of users representatively. RESULTS: Results show that policy goals were being delivered, with indications of changes to clinical practice, and improved clinical governance. Promotion, training and support needs to be extensive, and tailored to needs, but users are not always aware they need training. The sharing of passwords cast doubts on the reliability of some usage data. CONCLUSIONS: Digital health library services, delivered at the point of care, are changing the way some clinicians practise. A combination of qualitative and quantitative evaluation methods are needed to assess digital library services

3D image analysis for pedestrian detection

A method for solving the dense disparity stereo correspondence problem is presented in this paper. This technique is designed specifically for pedestrian detection type applications. A new Ground Control Points (GCPs) scheme is introduced, using groundplane homography information to determine regions in which good GCPs are likely to occur. The method also introduces a dynamic disparity limit constraint to further improve GCP selection and dense disparity generation. The technique is applied to a real world pedestrian detection scenario with a background modeling system based on disparity and edges

The X-ray Transient XTE J2012+381

We present optical and infrared observations of the soft X-ray transient (SXT) XTE J2012+381 and identify the optical counterpart with a faint red star heavily blended with a brighter foreground star. The fainter star is coincident with the radio counterpart and appears to show weak H alpha emission and to have faded between observations. The RXTE/ASM lightcurve of XTE J2012+381 is unusual for an SXT in that after an extended linear decay, it settled into a plateau state for about 40 days before undergoing a weak mini-outburst. We discuss the nature of the object and suggest similarities to long orbital period SXTs.Comment: 5 pages, 7 postscript figures included, uses mn.sty. Accepted for publication in MNRA

The Introduction of Anthropometrics into Development and Labor Economics

We trace the introduction of anthropometric indicators into development and labor economics in the late 1970s

Visualisation, Story And Metaphor As Tools To Build Self-Belief And Moral Awareness. An Ethnographic Case Study With Disengaged Pupils.

This case study of the Swindon Youth Empowerment Project 2001-2007, explores personal and social transformations when young people are encouraged to talk through their life choices conceptually using visualisation, symbol and metaphor. This educational project was designed to empower disaffected pupils in urban schools who are failing academically. They are referred to as ‘dispirited’ as they lacked motivation and ambition. The SYEP project is unique in that the procedure was created by the team and has no direct parallels. The fieldwork took place over three years, 2004-2007 with the researcher working as ethnographer as an outsider to the project. Data collection has included ethnographic observations, of training and events, and planning meetings. Interviews were conducted, group and individual pupils, teachers and learning mentors. The research drew on naturalistic data of the pupils involved, taken before, during and after the intervention. In doing so the team were trained to become evaluators and researchers. The researcher was allowed access to the work in order to encourage a long-term culture of evaluation, in schools as well as in the project. The research used a range of qualitative and ethnographic data collection methods and encouraged co-researcher dialogue. The analytical process was interpretative. The research demonstrates a clear effect on some of the young people involved. It reveals a range of factors contributing to this success. It also discusses the learning and development processes of the project team, including the process by which evaluation was improved and a future action plan is set. It locates the benefits of the project in relation to theoretical discussions about holistic education, self-belief, emotional literacy and wellbeing, and therapeutic approaches. It argues that young people can transcend their limited world view, learning to see themselves differently as people with energy, potential, compassion and the ability to affect positive change. In this they can reach out to others and with others, building moral understanding and cascading positive attitudes and energies to those around them