Gauge invariant extremization on the lattice

Recently, a method was proposed and tested to find saddle points of the action in simulations of non-abelian lattice gauge theory. The idea, called `extremization', is to minimize \int(\dl S/\dl A_\mu)^2. The method was implemented in an explicitly gauge variant way, however, and gauge dependence showed up in the results. Here we show how extremization can be formulated in a way that preserves gauge invariance on the lattice. The method applies to any gauge group and any lattice action. The procedure is worked out in detail for the standard plaquette action with gauge groups U(1) and SU(N).Comment: 7 pages, LaTeX, Oxford preprint OUTP-92-16

Clinical genetics and the problem with unqualified confidentiality.

In his article “A Defense of Unqualified Medical Confidentiality,” Kipnis provides a persuasive argument as to why maintaining unqualified confidentiality is the most effective way of preventing harm to third parties in the health-care setting (Kipnis 2006). However, difficulties emerge when it is applied to the field of clinical genetics. The familial context of clinical genetics means that routine sharing of information is a fundamental aspect of good clinical practice. We argue that, reflecting this premise of sharing information in clinical genetics, the most effective way to prevent harm to third parties is to advocate a “qualified confidentiality.” In making this claim, we challenge two assertions Kipnis relies upon in his argument for upholding unqualified confidentiality: 1) that unqualified confidentiality combined with attempts at “creative” means to elicit disclosure to at-risk third parties is the most effective way to minimise harm; and 2) that under unqualified confidentiality, individuals will actually become more likely to take responsibility for their own actions and health (Kipnis 2006, 7). We illustrate this challenge with reference to the following Case of The Ill Father: Steve and Jenny separated 10 years ago but still see the same doctor. Their daughter Kate is 16 years old and lives with Jenny, along with a younger brother and sister. Recently, Steve has been diagnosed with a form of bowel cancer called Familial Adenomatous Polyposis (FAP), a genetic condition that causes small polyps to develop in the bowel. These polyps develop into cancer if left unchecked but screening and surgical intervention reduces morbidity and mortality. Because Steve carries the FAP gene mutation, Kate has a 50% chance of inheriting it as well. If she knew of this risk, Kate could choose to have a genetic test and if positive, commence annual screening. However, Kate is not aware and Steve has said he does not plan to tell her.This article was written by Dr Ainsley Newson during the time of her employment with the University of Bristol, UK (2006-2012). Self-archived in the Sydney eScholarship Repository with permission of Bristol University, Sept 2014

Clinical genetics and the problem with unqualified confidentiality.

In his article “A Defense of Unqualified Medical Confidentiality,” Kipnis provides a persuasive argument as to why maintaining unqualified confidentiality is the most effective way of preventing harm to third parties in the health-care setting (Kipnis 2006). However, difficulties emerge when it is applied to the field of clinical genetics. The familial context of clinical genetics means that routine sharing of information is a fundamental aspect of good clinical practice. We argue that, reflecting this premise of sharing information in clinical genetics, the most effective way to prevent harm to third parties is to advocate a “qualified confidentiality.” In making this claim, we challenge two assertions Kipnis relies upon in his argument for upholding unqualified confidentiality: 1) that unqualified confidentiality combined with attempts at “creative” means to elicit disclosure to at-risk third parties is the most effective way to minimise harm; and 2) that under unqualified confidentiality, individuals will actually become more likely to take responsibility for their own actions and health (Kipnis 2006, 7). We illustrate this challenge with reference to the following Case of The Ill Father: Steve and Jenny separated 10 years ago but still see the same doctor. Their daughter Kate is 16 years old and lives with Jenny, along with a younger brother and sister. Recently, Steve has been diagnosed with a form of bowel cancer called Familial Adenomatous Polyposis (FAP), a genetic condition that causes small polyps to develop in the bowel. These polyps develop into cancer if left unchecked but screening and surgical intervention reduces morbidity and mortality. Because Steve carries the FAP gene mutation, Kate has a 50% chance of inheriting it as well. If she knew of this risk, Kate could choose to have a genetic test and if positive, commence annual screening. However, Kate is not aware and Steve has said he does not plan to tell her.This article was written by Dr Ainsley Newson during the time of her employment with the University of Bristol, UK (2006-2012). Self-archived in the Sydney eScholarship Repository with permission of Bristol University, Sept 2014

Learning Curves and p-charts for a preliminary estimation of asymptotic performances of a manufacturing process

This paper presents a method for a preliminary estimation of asymptotic performances of a manufacturing process based on the knowledge of its learning curve estimated during the setting up of p-chart. The main novelties of the method are the possibility of estimating the asymptotic variability of a process and providing a simple approach for evaluating the period of revision of process control limits. An application of the method to a real example taken from the literature is also provided

Ubiquinone status in neurons and astrocytes: The effects of nitrosative stress, lovastatin.

An HPLC method has been established for the determination of ubiquinone (C0Q9 and C0Q10) levels in biological samples. This necessitated the synthesis of a novel internal standard for C0Q9 and C0Q10 measurement in rodent tissue. Rat glial cell lines contained C0Q9 as the predominant ubiquinone isoform this was C0Q10 in human tissue. Comparison with primary cultures of rat astrocytes showed that these human and rat glial cancer cell lines had relatively less CoQ9+i0 than primary glial cultures, possibly reflecting a lower dependence of transformed cells upon OXPHOS for ATP generation. Lovastatin decreased C0Q9 (but not C0Q10) in primary astrocytes and glial cell lines. Moreover, glial cell lines displayed an approximately 10-fold higher sensitivity to lovastatin or its P-hydroxy acid isoform than primary rat astrocyte cultures. Cellular C0Q9 levels did not appear to be limiting for mitochondrial complex II+III activity, thus it is possible that C0Q10 is more intimately involved in OXPHOS than C0Q9. Primary cultures of rat astrocytes and neurons contained approximately equal levels of C0Q9. However C0Q10 levels were significantly higher in neuronal cultures. In contrast to transformed cell lines, the neuron's reliance on mitochondrial OXPHOS to synthesise ATP may manifest as higher cellular availability of C0Q10 Activation of iNOS in rat primary astrocytes to generate nitric oxide (NO) for 24h did not alter C0Q9 or C0Q10 levels. Following 36h exposure, activation of iNOS significantly decreased C0Q9 and C0Q10. An NO-donor decreased astrocyte C0Q9 and C0Q10 after 24h exposure, while in neurons, both CoQ isoforms were maintained. Additionally 36h exposure of astrocytes to DETA-NO appeared to cause a recovery in the amount of C0Q9 and C0Q10, possibly representing a protective effect in response to RNS exposure. Additionally, preliminary data demonstrated that small interfering RNA (siRNA) may decrease C0Q9 but not C0Q10 in rat primary astrocytes although not HEK293T cells

Modeling the response of tropical highland herbaceous grassland species to climate change:the case of the Arsi mountains of Ethiopia

AbstractGlobal warming is forcing plant and animal species to respond either through pole-ward or upslope migration to adjust to temperature increases, and grassland communities are not an exception to this phenomenon. In this study, we modeled the response of herbaceous species of grasslands within the Arsi Mountains in Ethiopia under no-migration and with migration scenarios to the projected 4.2°C increase of temperature by 2090 (under the A2 emission scenario). For 67 species of grasses and legumes, we determined the current and predicted altitudinal limits and calculated current and projected area coverage using a Digital Elevation Model. The results indicated that the projected warming significantly reduced altitudinal ranges and habitat areas of all the species studied. All the studied species faced range contraction and habitat loss with range shift gaps among forty two species under the no-migration scenario. With the migration scenario, however, the forty two species with range shift gaps are predicted to benefit from at least some habitat area retention. Between growth forms, legumes are predicted to lose significantly more habitat area than grasses under the no-migration scenario while no significant difference in habitat area loss is predicted under the migration scenario. It can be concluded that management options are required to facilitate upslope species migration to survive under the warming climate. This could involve leaving suitable dispersal corridors and assisted colonization depending on species behavior and level of extinction risk predicted under the projected warming

Cationic rhodium(I) and iridium(I) α-diimine complexes

AbstractCondensation of glyoxal with fluoroarylanilines [ArFNH2; ArF=4-C6H4F; 2,4-C6H3F2; 2,4,6-C6H2F3] generates new fluorine-substituted aryl α-diimines, ArFNCHCHNArF; ArF=4-C6H4F and 2,4,6-C6H2F3 have been structurally characterised. Displacement of acetonitrile from [M(COD)(MeCN)2][BF4] (M=Rh, Ir, COD=1,5-cyclooctadiene) with fluorine- and non-fluorine-substituted aryl α-diimines yields cationic rhodium(I) and iridium(I) complexes, that can be carbonylated to [M(CO)2(α-diimine)][BF4]

Resilience engineering as a quality improvement method in healthcare

Current approaches to quality improvement rely on the identification of past problems through incident reporting and audits or the use of Lean principles to eliminate waste, to identify how to improve quality. In contrast, Resilience Engineering (RE) is based on insights from complexity science, and quality results from clinicians’ ability to adapt safely to difficult situations, such as a surge in patient numbers, missing equipment or difficult unforeseen physiological problems. Progress in applying these insights to improve quality has been slow, despite the theoretical developments. In this chapter we describe a study in the Emergency Department of a large hospital in which we used RE principles to identify opportunities for quality improvement interventions. In depth observational fieldwork and interviews with clinicians were used to gather data about the key challenges faced, the misalignments between demand and capacity, adaptations that were required, and the four resilience abilities: responding, monitoring, anticipating and learning. Data were transcribed and used to write extended resilience narratives describing the work system. The narratives were analysed thematically using a combined deductive/inductive approach. A structured process was then used to identify potential interventions to improve quality. We describe one intervention to improve monitoring of patient flow and organisational learning about patient flow interventions. The approach we describe is challenging and requires close collaboration with clinicians to ensure accurate results. We found that using RE principles to improve quality is feasible and results in a focus on strengthening processes and supporting the challenges that clinicians face in their daily work

Algebraic geometric comparison of probability distributions

We propose a novel algebraic framework for treating probability distributions represented by their cumulants such as the mean and covariance matrix. As an example, we consider the unsupervised learning problem of finding the subspace on which several probability distributions agree. Instead of minimizing an objective function involving the estimated cumulants, we show that by treating the cumulants as elements of the polynomial ring we can directly solve the problem, at a lower computational cost and with higher accuracy. Moreover, the algebraic viewpoint on probability distributions allows us to invoke the theory of Algebraic Geometry, which we demonstrate in a compact proof for an identifiability criterion

The effect of scleral search coil lens wear on the eye

BACKGROUND/AIM Scleral search coils are used to measure eye movements. A recent abstract suggests that the coil can affect the eye by decreasing visual acuity, increasing intraocular pressure, and damaging the corneal and conjunctival surface. Such findings, if repeated in all subjects, would cast doubt on the credibility of the search coil as a reliable investigative technique. The aim of this study was to reassess the effect of the scleral search coil on visual function. METHODS Six volunteer subjects were selected to undergo coil wear and baseline measurements were taken of logMAR visual acuity, non-contact tonometry, keratometry, and slit lamp examination. Four drops of 0.4% benoxinate hydrochloride were instilled before insertion of the lens by an experienced clinician. The lens then remained on the eye for 30 minutes. Measurements of the four ocular health parameters were repeated after 15 and 30 minutes of lens wear. The lens was then removed and the health of the eye reassessed. RESULTS No obvious pattern of change was found in logMAR visual acuity, keratometry, or intraocular pressure. The lens did produce changes to the conjunctival and corneal surfaces, but this was not considered clinically significant. CONCLUSION Search coils do not appear to cause any significant effects on visual function. However, thorough prescreening of subjects and post-wear checks should be carried out on all coil wearers to ensure no adverse effects have been caused