Work relations for a system governed by Tsallis statistics

We derive analogues of the Jarzynski equality and Crooks relation to characterise the nonequilibrium work associated with changes in the spring constant of an overdamped oscillator in a quadratically varying spatial temperature profile. The stationary state of such an oscillator is described by Tsallis statistics, and the work relations for certain processes may be expressed in terms of q-exponentials. We suggest that these identities might be a feature of nonequilibrium processes in circumstances where Tsallis distributions are found

Deposition of organic thin films by plasma and photochemical techniques

The work detailed in this thesis concerns organic thin films synthesised either using R.F. inductively coupled plasmas excited in unsaturated monomers containing either fluorine or a nitrile group, or else irradiating the said monomers in vacuo using ultraviolet light. The effect of the following parameters on the composition and structure of the resultant films was determined using ESCA/XPS : a) power input to the R.F. plasma system, b) photon flux during UV irradiation, c) monomer type (including structural isomerism), and d) monomer flow rate. Relative system deposition rates were rationalised in terms of Yasuda's parameter, W/FM, which was found to hold true qualitatively, if not quantitatively. Introduction of halogen vapour to the plasma system in the presence of nitrile monomers physically decreased the glow volume. Analysis by ESCA and UV absorption spectroscopy revealed the presence of ionic halogen species in the resultant films. An overall decrease in deposition rate of the system was also observed. A similar result for the latter was seen for UV irradiation in the presence of iodine. The results were rationalised by assigning a free radical mechanism for both plasma and photochemical film deposition which is inhibited by halogens. Films formed by irradiation at &gt;200 nm were found to have differing chemical compositions compared to those obtained in the vacuum ultraviolet (<200 nm). This result was attributed to the differing photochemistries occurring in the two wavelength regions. Reference to the gas-phase photochemical literature enabled identification of the likely intermediates and term states involved, including 1,1 and 1,2 molecular elimination from ethylenic monomers in the vacuum UV to give the respective ethynes, together with secondary photolysis products. Consequently a mechanism for surface photopolymerisation was outlined which was compared with that proposed for plasma polymerisation, both of which involve vibrationally excited ground states for the monomers studied

Case Report: Successful Staged Ureteroscopic Treatment of a 5 cm Staghorn Renal Calculus

It is widely accepted that percutaneous nephrostolithotorny (PCNL) is the standard of choice for the removal of large staghorn renal calculi. Although data exists supporting a stagad ureteroscopic as an alternate treatment for stones up to 3 cm in select patients, little data exists to support a ureteroscopic approach for stones as large as 5 cm. We present a case of a 68 year old female with a 5 cm staghorn renal calculus managed successfully with a staged ureteroscopic approach. A staged ureteroscopic approach can be effective in treating stones as large as 5 cm

Molecular evolutionary consequences of island colonization

Island endemics are expected to have low effective population sizes (Ne), first because some may experience population bottlenecks when they are founded, and second because they have restricted ranges. Therefore, we expect island species to have reduced genetic diversity, inefficient selection, and reduced adaptive potential compared with their mainland counterparts. We used both polymor- phism and substitution data to address these predictions, improving on the approach of recent studies that only used substitution data. This allowed us to directly test the assumption that island species have small values of Ne. We found that island species had significantly less genetic diversity than mainland species; however, this pattern could be attributed to a subset of island species that appeared to have undergone a recent population bottleneck. When these species were excluded from the analysis, island and mainland species had similar levels of genetic diversity, despite island species occupying considerably smaller areas than their mainland counterparts. We also found no overall difference between island and mainland species in terms of the effectiveness of selection or the mutation rate. Our evidence suggests that island colonization has no lasting impact on molecular evolution. This surprising result highlights gaps in our knowledge of the relationship between census and effective population size

A weighted genetic risk score using all known susceptibility variants to estimate rheumatoid arthritis risk

Background: There is currently great interest in the incorporation of genetic susceptibility loci into screening models to identify individuals at high risk of disease. Here, we present the first risk prediction model including all 46 known genetic loci associated with rheumatoid arthritis (RA). Methods: A weighted genetic risk score (wGRS) was created using 45 RA non-human leucocyte antigen (HLA) susceptibility loci, imputed amino acids at HLA-DRB1 (11, 71 and 74), HLA-DPB1 (position 9) HLA-B (position 9) and gender. The wGRS was tested in 11 366 RA cases and 15 489 healthy controls. The risk of developing RA was estimated using logistic regression by dividing the wGRS into quintiles. The ability of the wGRS to discriminate between cases and controls was assessed by receiver operator characteristic analysis and discrimination improvement tests. Results: Individuals in the highest risk group showed significantly increased odds of developing anti-cyclic citrullinated peptide-positive RA compared to the lowest risk group (OR 27.13, 95% CI 23.70 to 31.05). The wGRS was validated in an independent cohort that showed similar results (area under the curve 0.78, OR 18.00, 95% CI 13.67 to 23.71). Comparison of the full wGRS with a wGRS in which HLA amino acids were replaced by a HLA tag single-nucleotide polymorphism showed a significant loss of sensitivity and specificity. Conclusions: Our study suggests that in RA, even when using all known genetic susceptibility variants, prediction performance remains modest; while this is insufficiently accurate for general population screening, it may prove of more use in targeted studies. Our study has also highlighted the importance of including HLA variation in risk prediction models

Reported child awareness of parental depression

Aims and method To determine rates of parent-reported child awareness of parental depression, examine characteristics of parents, children and families according to child awareness, and explore whether child awareness is associated with child psychopathology. Data were available from 271 families participating in the Early Prediction of Adolescent Depression (EPAD) study, a longitudinal study of offspring of parents with recurrent depression. Results Seventy-three per cent of participating children were perceived as being aware of their parent's depression. Older children, and children of parents who experienced more severe depression, were more likely to be aware. Awareness was not associated with child psychopathology. Clinical implications Considering children in the context of parental depression is important. Child awareness may influence their access to early intervention and prevention programmes. Further research is needed to understand the impact of awareness on the child