Non-linear conductance of disordered quantum wires

The self-consistent electron potential in a current-carrying disordered quantum wire is spatially inhomogeneous due to the formation of resistivity dipoles across scattering centres. In this paper it is argued that these inhomogeneities in the potential result in a suppression of the differential conductance of such a wire at finite applied voltage. A semi-classical argument allows this suppression, quadratic in the voltage, to be related directly to the amount of intrinsic defect scattering in the wire. This result is then tested against numerical calculations.

Defensio Prima and the Latin Poets

This chapter, in a prize-winning volume, examines ways in which Milton’s recourse to Latin poetry in Defensio Prima serves a much deeper purpose than that of merely illustrating or lending authority to his argument. Rather, it is argued, the defence engages with a variety of Latin intertexts (Plautus, Terence, Horace, Petronius), which in turn give birth to a range of dramatis personae, with whom Salmasius is ironically and somewhat kaleidoscopically equated. This methodology lends particular force to Milton’s rhetoric of invective whilst hopefully laying to rest the fallacy that his Latin prose writings were writing during a period of ‘poetic inactivity.’ For this is a prose work that is poetically as well as politically aware.

In vitro study of the efficacy of acrylic bone cement loaded with supplementary amounts of gentamicin: Effect on mechanical properties, antibiotic release, and biofilm formation

Background: Infection remains a severe complication following a total hip replacement. If infection is suspected when revision surgery is being performed, additional gentamicin is often added to the cement on an ad hoc basis in an attempt to reduce the risk of recurrent infection.

Methods and results: In this in vitro study, we determined the effect of incorporating additional gentamicin on the mechanical properties of cement. We also determined the degree of gentamicin release from cement, and also the extent to which biofilms of clinical Staphylococcus spp. isolates form on cement in vitro. When gentamicin was added to unloaded cement (1–4 g), there was a significant reduction in the mechanical performance of the loaded cements compared to unloaded cement. A significant increase in gentamicin release from the cement over 72 h was apparent, with the amount of gentamicin released increasing significantly with each additional 1 g of gentamicin added. When overt infection was modeled, the incorporation of additional gentamicin did result in an initial reduction in bacterial colonization, but this beneficial effect was no longer apparent by 72 h, with the clinical strains forming biofilms on the cements despite the release of high levels of gentamicin.

Interpretation: Our findings indicate that the addition of large amounts of gentamicin to cement is unlikely to eradicate bacteria present as a result of an overt infection of an existing implant, and could result in failure of the prosthetic joint because of a reduction in mechanical performance of the bone cement.

The Kitai criterion and backward shifts

It is proved that for any separable infinite dimensional Banach space X, there is a bounded linear operator T on X such that T satisfies the Kitai criterion. The proof is based on a quasisimilarity argument and on showing that I + T satisfies the Kitai criterion for certain backward weighted shifts T.

Non-weakly supercyclic operators

Several methods based on an easy geometric argument are provided to prove that a given operator is not weakly supercyclic. The methods apply to different kinds of operators like composition operators or bilateral weighted shifts. In particular, it is shown that the classical Volterra operator is not weakly supercyclic on any of the LP [0, 1] spaces, 1

'An aid to mental health': natural history, alienists and therapeutics in Victorian Scotland

In the nineteenth century natural history was widely regarded as a rational and ‘distracting’ pursuit that countered the ill-effects, physical and mental, of urban life. This familiar argument was not only made by members of naturalists’ societies but was also borrowed and adapted by alienists concerned with the moral treatment of the insane. This paper examines the work of five long-serving superintendents in Victorian Scotland and uncovers the connections made between an interest in natural history and the management of mental disease. In addition to recovering a significant influence on the conduct of several alienists the paper explores arguments made outside the asylum walls in favour of natural history as an aid to mental health. Investigating the promotion of natural history as a therapeutic recreation in Scotland and elsewhere reveals more fully the moral and cultural significance attached to natural history pursuits in the nineteenth century.

Evidence against dietary advanced glycation endproducts being a risk to human health

In vivo, advanced glycation endproducts (AGEs) are linked to various diseases, particularly those associated with diabetes. AGEs are also formed when many foods are thermally processed. The extent to which dietary AGEs are absorbed by the gastrointestinal (GI) tract and their possible role in the onset and promotion of disease are currently of considerable interest. This paper reviews information that supports the argument that dietary AGEs are not a risk to human health.

Parent-off spring associations in wintering brent geese: parental investment or mutual assistance?

The continued parent-offspring associations in the Eastern Canadian High Arctic light-bellied brent goose Branta bernicla hrota was examined to determine whether this is an example of continued parental investment or mutual assistance. Adults with juveniles spend more than twice as much time being vigilant and aggressive than do those without offspring. The loss of a partner, however, does not result in the remaining parent increasing parental care but does result in increased 'self-care' by the juveniles. Neither parents nor single-parent juveniles appear to pay an energetic cost relative to non-parental adults and two-parent juveniles, respectively. Differences in the feeding distribution of parents and non-parents and equivalent or better physical condition suggests that families are able to maintain access to a superior food supply over the winter. Passive 'assistance' by juveniles may assist in maintaining this position in favoured areas, and this is achieved with little overt aggression. The present study thus provides no data that show a net cost to parents by remaining with their juveniles over the winter period. Thus, mutual assistance might be a better explanation of the prolonged association rather than a period of parental investment with an overall cost.

Is hyperfiltration associated with the future risk of developing diabetic nephropathy? A meta-analysis.

Aims/hypothesis Glomerular hyperfiltration is a well established phenomenon occurring early in some patients with type 1 diabetes. However, there is no consistent answer regarding whether hyperfiltration predicts later development of nephropathy. We performed a systematic review and meta-analysis of observational studies that compared the risk of developing diabetic nephropathy in patients with and without glomerular hyperfiltration and also explored the impact of baseline GFR.

Methods A systematic review and meta-analysis was carried out. Cohort studies in type 1 diabetic participants were included if they contained data on the development of incipient or overt nephropathy with baseline measurement
of GFR and presence or absence of hyperfiltration.

Results We included ten cohort studies following 780 patients. After a study median follow-up of 11.2 years, 130 patients had developed nephropathy. Using a random effects model, the pooled odds of progression to a minimum
of microalbuminuria in patients with hyperfiltration was 2.71 (95% CI 1.20–6.11) times that of patients with normofiltration. There was moderate heterogeneity (heterogeneity test p=0.05, measure of degree of inconsistency=48%) and some evidence of funnel plot asymmetry, possibly due to publication bias. The pooled weighted mean difference in baseline GFR was 13.8 ml min-1 1.73 m-2 (95% CI 5.0–22.7) greater in the group progressing to nephropathy than in those not progressing (heterogeneity test p<0.01).

Conclusions/interpretation In published studies, individuals with glomerular hyperfiltration were at increased risk of progression to diabetic nephropathy using study level data. Further larger studies are required to explore this relationship and the role of potential confounding variables.

Cardiovascular disease risk profiles among 'healthy' siblings of patients with early-onset cardiovascular disease:Application of the new SCORE system

BACKGROUND: Cardiovascular disease (CVD) occurs more frequently in individuals with a family history of premature CVD. Within families the demographics of CVD are poorly described. DESIGN: We examined the risk estimation based on the Systematic Coronary Risk Evaluation (SCORE) system and the Joint British Guidelines (JBG) for older unaffected siblings of patients with premature CVD (onset ≤55 years for men and ≤60 years for women). METHODS: Between August 1999 and November 2003 laboratory and demographic details were collected on probands with early-onset CVD and their older unaffected siblings. Siblings were screened for clinically overt CVD by a standard questionnaire and 12-lead electrocardiogram (ECG). RESULTS: A total of 790 siblings was identified and full demographic details were available for 645. The following siblings were excluded: 41 with known diabetes mellitus; seven with random plasma glucose of 11.1 mmol/l or greater; and eight with ischaemic ECG. Data were analysed for 589 siblings from 405 families. The mean age was 55.0 years, 43.1% were men and 28.7% were smokers. The mean total serum cholesterol was 5.8 mmol/l and hypertension was present in 49.4%. Using the SCORE system, when projected to age 60 years, 181 men (71.3%) and 67 women (20.0%) would be eligible for risk factor modification. Using JBG with a 10-year risk of 20% or greater, 42 men (16.5%) and four women (1.2%) would be targeted. CONCLUSIONS: Large numbers of these asymptomatic individuals meet both European and British guidelines for the primary prevention of CVD and should be targeted for risk factor modification. The prevalence of individuals defined as eligible for treatment is much higher when using the SCORE system. © 2007 European Society of Cardiology.

The postmodernist war on evidence-based practice

In this paper, we examine the war of words between those who contend that health care practice, including nursing, should primarily be informed by research (the evidence-based practice movement), and those who argue that there should be no restrictions on the sources of knowledge used by practitioners (the postmodernists). We review the postmodernist interventions of Dave Holmes and his colleagues, observing that the postmodernist style to which they adhere, which includes the use of continental philosophy, metaphors, and acerbic delivery, tends to obscure their substantive arguments. The heated nature of some responses to them has tended to have the same effect. However, the substantive arguments are important. Five main postmodernist charges are identified and discussed. The first argument, that the notion of ‘best evidence’ implies a hierarchical and exclusivist approach to knowledge, is persuasive. However, the contention that this hierarchy is maintained by the combined pressures of capitalism and vested interests within academia and the health services, is less well founded. Nevertheless, postmodernist contentions that the hierarchy embraced by the evidence-based practice movement damages health care because it excludes other forms of evidence that are needed to understand the complexity of care, it marginalizes important aspects of clinical knowledge, and it fails to take account of individuals or their experience, are all seen to be of some merit. However, we do not share the postmodernist conclusion that this adds up to a fascist order. Instead, we characterize evidence-based practice as a necessary but not sufficient component of health care knowledge.

Complete Sudoku - extra rules for more symmetry

We propose some extra rules to add to the well-known Sudoku puzzle and present an argument to justify their inclusion. The rules mean that puzzles can be created with fewer cells completed initially yet which still have only one solution. We have created a Web-based program which can be used to generate and solve both standard and extended (Complete) puzzles.

'Calling the Judiciary to Account for the Past: Transitional Justice and Judicial Accountability in Nigeria'

Institutional and individual accountability is an important feature of societies in transition from conflict or authoritarian rule. The imperative of accountability has both normative and transformational underpinnings in the context of restoration of the rule of law and democracy. This article argues a case for extending the purview of truth-telling processes to the judiciary in postauthoritarian contexts. The driving force behind the inquiry is the proposition that the judiciary as the third arm of government at all times participates in governance. To contextualize the argument, I focus on judicial governance and accountability within the paradigm of Nigeria’s transition to democracy after decades of authoritarian military rule.

Novel periodically loaded E-plane filters

Novel E-plane waveguide filters with periodically loaded resonators are proposed. The proposed filters make use of the slow wave effect in order to achieve improved stopband performance and size reduction of roughly 50% without introducing any complexity in the fabrication process. Numerical and experimental results are presented to validate the argument.

Novel periodically loaded ridged waveguide resonators

Novel periodically loaded E-plane waveguide resonators are presented in this paper. The proposed resonators make use of the slow-wave effect in order to achieve significantly increased loaded Q values for resonators of constant volume, as compared to their homogeneous counterparts, without introducing any complexity in the fabrication process. Numerical and experimental results are presented to validate the argument. (C) 2003 Wiley Periodicals, Inc.