Fabrication of low-OH GeS<inf>2</inf>glasses and multimode fibres for mid-IR applications

The fabrication properties of ternary and quaternary GeS 2 -based chalcogenide glasses are discussed in view of the removal impurities and control of crystallization by controlling the starting composition, raw materials purification and fabrication steps. The two specific compositions discussed for glass and fibre fabrication are: GeS 2 -Ga 2 S 3 -CsI and GeS 2 -Ga 2 S 3 -CsI-SnS which were optimised for multimode fibre fabrication by investigating the thermal and viscosity properties. For chemical process control in food, pharmaceutical and petrochemical industry, optical fibre sensors operating above 200 °C in chemical process environment are required. For food and pharmaceutical it is also safer to use materials which are non-toxic. With these aims in mind we focussed on designing the glass structure by raising the T g from 350 °C in ternary glass composition to 450 °C. By modifying the glass structure with the addition of SnS, the probability of near-T g and sub-T g structural relaxation in optical fibres, derived from quaternary compositions. For the analysis of structural modification in glass, we have systematically carried out Raman spectroscopy using 514 and 633 nm sources. We report changes in the structure as a function of composition. The Raman spectroscopic analysis is also complemented by the IR reflection and transmission spectroscopy for a more comprehensive characterisation the vibrational structures. The glass compositions were also analysed for their devitrification and near T g relaxation behaviour. On the basis of the devitrification characteristics we have also characterised the thermal stabilities of various compositions under thermal cyclic loading in the transformation region. The structural relaxation behaviour above T g was also characterised by using a differential mechanical analyser by measuring the viscosity

Challenges and solutions during analysis in a longitudinal narrative case study.

AIM: To describe the challenges faced by those performing complex qualitative analysis during a narrative study and to offer solutions. BACKGROUND: Qualitative research requires rigorous analysis. However, novice researchers often struggle to identify appropriately robust analytical procedures that will move them from their transcripts to their final findings. The lack of clear and detailed accounts in the literature that consider narrative analysis and how to address some of the common challenges researchers face add to this problem. DATA SOURCES: A longitudinal narrative case study exploring the personal and familial changes reported by uninjured family members during the first year of another family member's traumatic brain injury. Review methods This is a methodological paper. DISCUSSION: The challenges of analysis included: conceptualising analysis; demonstrating the relationship between the different analytical layers and the final research findings; interpreting the data in a way that reflected the priorities of a narrative approach; and managing large quantities of data. The solutions explored were: the mapping of analytic intentions; aligning analysis and interpretation with the conceptual framework; and the use of matrices to store and manage quotes, codes and reflections. CONCLUSION: Working with qualitative data can be daunting for novice researchers. Ensuring rigorous, transparent, and auditable data analysis procedures can further constrain the interpretive aspect of analysis. Implications for research/practice The solutions offered in this paper should help novice researchers to manage and work with their data, assisting them to develop the confidence to be more intuitive and creative in their research

Truncated Schwinger-Dyson Equations and Gauge Covariance in QED3

We study the Landau-Khalatnikov-Fradkin transformations (LKFT) in momentum space for the dynamically generated mass function in QED3. Starting from the Landau gauge results in the rainbow approximation, we construct solutions in other covariant gauges. We confirm that the chiral condensate is gauge invariant as the structure of the LKFT predicts. We also check that the gauge dependence of the constituent fermion mass is considerably reduced as compared to the one obtained directly by solving SDE.Comment: 17 pages, 11 figures. v3. Improved and Expanded. To appear in Few Body System

CR1 Knops blood group alleles are not associated with severe malaria in the Gambia

The Knops blood group antigen erythrocyte polymorphisms have been associated with reduced falciparum malaria-based in vitro rosette formation (putative malaria virulence factor). Having previously identified single-nucleotide polymorphisms (SNPs) in the human complement receptor 1 (CR1/CD35) gene underlying the Knops antithetical antigens Sl1/Sl2 and McC(a)/McC(b), we have now performed genotype comparisons to test associations between these two molecular variants and severe malaria in West African children living in the Gambia. While SNPs associated with Sl:2 and McC(b+) were equally distributed among malaria-infected children with severe malaria and control children not infected with malaria parasites, high allele frequencies for Sl 2 (0.800, 1,365/1,706) and McC(b) (0.385, 658/1706) were observed. Further, when compared to the Sl 1/McC(a) allele observed in all populations, the African Sl 2/McC(b) allele appears to have evolved as a result of positive selection (modified Nei-Gojobori test Ka-Ks/s.e.=1.77, P-value &lt;0.05). Given the role of CR1 in host defense, our findings suggest that Sl 2 and McC(b) have arisen to confer a selective advantage against infectious disease that, in view of these case-control study data, was not solely Plasmodium falciparum malaria. Factors underlying the lack of association between Sl 2 and McC(b) with severe malaria may involve variation in CR1 expression levels

Barriers to innovation and sustainability at universities around the world

This paper explores the link between innovation and sustainability in the context of higher education, with the purpose of investigating the fundamental barriers for innovation and sustainable development in universities around the world. The method used involves both a quantitative and a qualitative approach, gathering the views of 301 experts from 172 universities across all continents. The results show that there are similar barriers across different geographical regions that require greater support from university administrations and management. In particular, the willingness of leaders, policy makers and decision-makers to envisage a sustainable future inside universities is often missing. Yet, without the support of senior management within a university, bottom-up sustainable initiatives seem destined to fail in the longer term due to a lack of investment and administrative support. This study also identifies that in order to yield the anticipated benefits, barriers need to be tackled in an integrated way, and that closer cooperation between sustainability researchers, university administrations and students is needed

What Can We Conclude from Death Registration? Improved Methods for Evaluating Completeness

Julie Rajaratnam and colleagues evaluate the performance of a suite of demographic methods that estimate the fraction of deaths registered and counted by civil registration systems, and identify three variants that generally perform the best

Microcolony Imaging of Aspergillus fumigatus Treated with Echinocandins Reveals Both Fungistatic and Fungicidal Activities

Background: The echinocandins are lipopeptides that can be employed as antifungal drugs that inhibit the synthesis of 1,3b-glucans within the fungal cell wall. Anidulafungin and caspofungin are echinocandins used in the treatment of Candida infections and have activity against other fungi including Aspergillus fumigatus. The echinocandins are generally considered fungistatic against Aspergillus species. Methods: Culture of A. fumigatus from conidia to microcolonies on a support of porous aluminium oxide (PAO), combined with fluorescence microscopy and scanning electron microscopy, was used to investigate the effects of anidulafungin and caspofungin. The PAO was an effective matrix for conidial germination and microcolony growth. Additionally, PAO supports could be moved between agar plates containing different concentrations of echinocandins to change dosage and to investigate the recovery of fungal microcolonies from these drugs. Culture on PAO combined with microscopy and image analysis permits quantitative studies on microcolony growth with the flexibility of adding or removing antifungal agents, dyes, fixatives or osmotic stresses during growth with minimal disturbance of fungal microcolonies. Significance: Anidulafungin and caspofungin reduced but did not halt growth at the microcony level; additionally both drugs killed individual cells, particularly at concentrations around the MIC. Intact but not lysed cells showed rapid recovery when the drugs were removed. The classification of these drugs as either fungistatic or fungicidal is simplistic. Microcolon