A note on a third order curvature invariant in static spacetimes

We consider here the third order curvature invariant $I=R_{\mu\nu\rho\sigma;\delta}R^{\mu\nu\rho\sigma;\delta}$ in static spacetimes ${\cal M}=R\times\Sigma$ for which $\Sigma$ is conformally flat. We evaluate explicitly the invariant for the $N$-dimensional Majumdar-Papapetrou multi black-holes solution, confirming that $I$ does indeed vanish on the event horizons of such black-holes. Our calculations show, however, that solely the vanishing of $I$ is not sufficient to locate an event horizon in non-spherically symmetric spacetimes. We discuss also some tidal effects associated to the invariant $I$.Comment: 5 pages, 3 figures. Extra material available at http://vigo.ime.unicamp.br/in

Measuring service encounters with the traumatic brain injury population

Functional therapy tasks are frequently cited as being important for the successful carry-over of treatment objectives. Service encounters, such as shopping or enquiring for information on the telephone, are typical community integration activities used with the traumatically brain injured (TBI) population. This paper explores the use of systemic functional linguistics in the measurement of performance in service encounters using Generic Structure Potential (GSP) analysis. Results are presented for GSP analysis of service encounters on the telephone to a bus timetable information service, and the police, for five TBI individuals and five matched controls. Service encounters differed according to the complexity of information requested and the interpersonal, or tenor relationships between participants. Differences were evident between TBI and control interactions in the use of generic structural elements. Variation in generic structure was demonstrated across the two types of service encounter. The potential of GSP to measure the dynamic linguistic patterns in everyday TBT interactions is discussed

CASTRO: A New Compressible Astrophysical Solver. II. Gray Radiation Hydrodynamics

We describe the development of a flux-limited gray radiation solver for the compressible astrophysics code, CASTRO. CASTRO uses an Eulerian grid with block-structured adaptive mesh refinement based on a nested hierarchy of logically-rectangular variable-sized grids with simultaneous refinement in both space and time. The gray radiation solver is based on a mixed-frame formulation of radiation hydrodynamics. In our approach, the system is split into two parts, one part that couples the radiation and fluid in a hyperbolic subsystem, and another parabolic part that evolves radiation diffusion and source-sink terms. The hyperbolic subsystem is solved explicitly with a high-order Godunov scheme, whereas the parabolic part is solved implicitly with a first-order backward Euler method.Comment: accepted for publication in ApJS, high-resolution version available at https://ccse.lbl.gov/Publications/wqzhang/castro2.pd

Ethical and compliance-competence evaluation: a key element of sound corporate governance

Motivated by the ongoing post-Enron refocusing on corporate governance and the shift by the Financial Services Authority (FSA) in the UK to promoting compliance- competence within the financial services sector, this paper demonstrates how template analysis can be used as a tool for evaluating compliance-competence. Focusing on the ethical dimension of compliance-competence, we illustrate how this can be subjectively appraised. We propose that this evaluation technique could be utilised as a starting point in informing senior management of corporate governance issues and be used to monitor and demonstrate key compliance and ethical aspects of an institution to external stakeholders and regulators

Women, know your limits: Cultural sexism in academia

Despite the considerable advances of the feminist movement across Western societies, in Universities women are less likely to be promoted, or paid as much as their male colleagues, or even get jobs in the first place. One way in which we can start to reflect on why this might be the case is through hearing the experiences of women academics themselves. Using feminist methodology, this article attempts to unpack and explore just some examples of ‘cultural sexism’ which characterise the working lives of many women in British academia.This article uses qualitative methods to describe and make sense of just some of those experiences. In so doing, the argument is also made that the activity of academia is profoundly gendered and this explicit acknowledgement may contribute to our understanding of the under-representation of women in senior positions

What are the important factors in health-related quality of life for people with aphasia? A systematic review

Objective: To determine factors associated with or predictive of poor health-related quality of life (HRQL) in people with aphasia poststroke. Better understanding of these factors can allow better targeting of rehabilitation programs. Data Sources: Electronic databases, covering medical (eg, Medline, Excerpta Medica Database, Evidence-Based Medicine Reviews, Cumulative Index to Nursing and Allied Health Literature, Ovid, Allied and Complementary Medicine Database) and social sciences (eg, PsycINFO) were searched and key experts were approached. Study Selection: Studies including specific information on the HRQL of people with aphasia poststroke using validated HRQL measures or established ways of analyzing qualitative data were included. Two reviewers independently screened studies against the eligibility criteria. Data Extraction: This was undertaken independently by 2 reviewers. Discrepancies were resolved by consensus. Quantitative studies were assessed for quality with Counsell and Dennis' critical appraisal tool for systematic review of prognostic models in acute stroke; qualitative studies with the Critical Appraisal Skills Program tool for qualitative research. Data Synthesis: Fourteen research reports met the eligibility criteria. Because of their high heterogeneity, the data synthesis was narrative. The evidence is not strong enough to determine the main predictors of HRQL in people with aphasia. Still, emotional distress/depression, severity of aphasia and communication disability, other medical problems, activity limitations, and aspects of social network and support were important factors. Conclusions: Emotional distress, aphasia severity, communication and activity limitations, other medical problems, and social factors affect HRQL. Stroke HRQL studies need to include people with aphasia and report separately on them, in order to determine the main predictors of their HRQL and to identify what interventions can best address them

Bolometric correction and spectral energy distribution of cool stars in Galactic clusters

We have investigated the relevant trend of the bolometric correction (BC) at the cool-temperature regime of red giant stars and its possible dependence on stellar metallicity. Our analysis relies on a wide sample of optical-infrared spectroscopic observations, along the 3500A-2.5micron wavelength range, for a grid of 92 red giant stars in five (3 globular + 2 open) Galactic clusters, along the -2.2<[Fe/H]<+0.4 metallicity range. Bolometric magnitudes have been found within an internal accuracy of a few percent. Making use of our new database, we provide a set of fitting functions for the V and K BC vs. Teff and broad-band colors, valid over the interval 3300K<Teff<5000K, especially suited for Red Giants. No evident drift of both BC(V) and BC(K) with [Fe/H] is found. Things may be different, however, for the B-band correction, given a clear (B-V) vs. [Fe/H] correlation in place for our data, with metal-poor stars displaying a "bluer" (B-V) with respect to the metal-rich sample, for fixed Teff. Our empirical bolometric scale supports the conclusion that (a) BC(K) from the most recent studies are reliable within <0.1 mag over the whole color/temperature range considered in this paper, and (b) the same conclusion apply to BC(V) only for stars warmer than ~3800K. At cooler temperatures the agreement is less general, and MARCS models are the only ones providing a satisfactory match to observations.Comment: 18 pages with 12 color figures and 12 tables. To appear in the MNRAS. Full spectral catalog of stars available at http://www.bo.astro.it/~eps/home.htm

Fracture energy evolution of two concretes resistant to the action of freeze-thaw cycles

The current standards that regulate use of structural concrete have highlighted the durability of concrete. However, how the fracture energy of concrete evolves under the action of freeze-thaw cycles is not well known. The fracture energy of two types of concrete, one with an air-entraining additive and the other with silica fume addition, is studied after four, 14 and 28 freeze-thaw cycles. The results obtained show that the concrete with an air-entraining additive was undamaged and that fracture energy grew slightly. In addition to this, they also showed that the concrete with silica fume addition suffered severe surface scaling and its fracture energy changed due to the greater fracture areas generated.<br><br>La actual normativa que rige el empleo de hormigón estructural ha puesto enfásis en la durabilidad del hormigón. Sin embargo, no se conoce cómo evoluciona la energía de fractura del hormigón sometido a ciclos hielo- deshielo, lo cual es de vital importancia para asegurar la durabilidad y el correcto comportamiento mecánico de las estructuras de hormigón en entornos con heladas durante su vida útil. Se ha estudiado la evolución de la energía de fractura de un hormigón con aireante y de un hormigón con humo de sílice después de 4, 14 y 28 ciclos hielo-deshielo realizando ensayos de fractura. Los resultados muestran cómo el hormigón con aireante no sufre daño por los ciclos hielo-deshielo y cómo la energía de fractura del mismo aumenta ligeramente. El hormigón con humo de sílice se daña por los ciclos hielo-deshielo y reduce su energía de fractura al aumentar el area fracturada