Condition number estimates for combined potential boundary integral operators in acoustic scattering

We study the classical combined field integral equation formulations for time-harmonic acoustic scattering by a sound soft bounded obstacle, namely the indirect formulation due to Brakhage-Werner/Leis/Panic, and the direct formulation associated with the names of Burton and Miller. We obtain lower and upper bounds on the condition numbers for these formulations, emphasising dependence on the frequency, the geometry of the scatterer, and the coupling parameter. Of independent interest we also obtain upper and lower bounds on the norms of two oscillatory integral operators, namely the classical acoustic single- and double-layer potential operators

Embracing technology for improving dental records and record keeping in the Republic of South Africa. A review.

Forensic odontology (FO) techniques are used to identify unknown remains and play an integral role in dental-legal cases. The utility of FO relies on accurate antemortem records – the creation and management of which continues to be a global challenge, albeit more acutely presenting in developing countries. Inadequate record keeping and management by the dental fraternity has made application of FO techniques for identifying unknown remains challenging. In addition, dental-legal cases such as in homicides, rapes, patient mismanagement and fraud are sometimes unresolved due to record keeping and health system shortcomings. This current status quo affects families and society: bereaved families are deprived of closure, and protracted litigations ensue, leading to various socioeconomic consequences

Two-stage coarsening mechanism in a kinetically constrained model of an attractive colloid

We study an attractive version of the East model using the real-space renormalization group (RG) introduced by Stella et al. The former is a kinetically constrained model with an Ising-like interaction between excitations, and shows striking agreement with the phenomonology of attractive colloidal systems. We find that the RG predicts two nonuniversal dynamic exponents, which suggests that in the out-of-equilibrium regime the model coarsens via a two-stage mechanism. We explain this mechanism physically, and verify this prediction numerically. In addition, we find that the characteristic relaxation time of the model is a non-monotonic function of attraction strength, again in agreement with numerical results.Comment: 10 page

Establishing gold standard approaches to rapid tranquillisation: a review and discussion of the evidence on the safety and efficacy of medications currently used

Background: Rapid tranquillisation is used when control of agitation, aggression or excitement is required. Throughout the UK there is no consensus over the choice of drugs to be used as first line treatment. The NICE guideline on the management of violent behaviour involving psychiatric inpatients conducted a systematic examination of the literature relating to the effectiveness and safety of rapid tranquillisation (NICE, 2005). This paper presents the key findings from that review and key guideline recommendations generated, and discusses the implications for practice of more recent research and information. Aims: To examine the evidence on the efficacy and safety of medications used for rapid tranquillisation in inpatient psychiatric settings. Method: Systematic review of current guidelines and phase III randomised, controlled trials of medication used for rapid tranquillisation. Formal consensus methods were used to generate clinically relevant recommendations to support safe and effective prescribing of rapid tranquillisation in the development of a NICE guideline. Findings: There is a lack of high quality clinical trial evidence in the UK and therefore a ‘gold standard’ medication regime for rapid tranquillisation has not been established. Rapid tranquillisation and clinical practice: The NICE guideline produced 35 recommendations on rapid tranquillisation practice for the UK, with the primary aim of calming the service user to enable the use of psychosocial techniques. Conclusions and implications for clinical practice: Further UK specific research is urgently needed that provides the clinician with a hierarchy of options for the clinical practice of rapid tranquillisation

Effects of Tetracaine on Voltage-activated Calcium Sparks in Frog Intact Skeletal Muscle Fibers

The properties of Ca2+ sparks in frog intact skeletal muscle fibers depolarized with 13 mM [K+] Ringer's are well described by a computational model with a Ca2+ source flux of amplitude 2.5 pA (units of current) and duration 4.6 ms (18 °C; Model 2 of Baylor et al., 2002). This result, in combination with the values of single-channel Ca2+ current reported for ryanodine receptors (RyRs) in bilayers under physiological ion conditions, 0.5 pA (Kettlun et al., 2003) to 2 pA (Tinker et al., 1993), suggests that 1–5 RyR Ca2+ release channels open during a voltage-activated Ca2+ spark in an intact fiber. To distinguish between one and greater than one channel per spark, sparks were measured in 8 mM [K+] Ringer's in the absence and presence of tetracaine, an inhibitor of RyR channel openings in bilayers. The most prominent effect of 75–100 μM tetracaine was an approximately sixfold reduction in spark frequency. The remaining sparks showed significant reductions in the mean values of peak amplitude, decay time constant, full duration at half maximum (FDHM), full width at half maximum (FWHM), and mass, but not in the mean value of rise time. Spark properties in tetracaine were simulated with an updated spark model that differed in minor ways from our previous model. The simulations show that (a) the properties of sparks in tetracaine are those expected if tetracaine reduces the number of active RyR Ca2+ channels per spark, and (b) the single-channel Ca2+ current of an RyR channel is ≤1.2 pA under physiological conditions. The results support the conclusion that some normal voltage-activated sparks (i.e., in the absence of tetracaine) are produced by two or more active RyR Ca2+ channels. The question of how the activation of multiple RyRs is coordinated is discussed

Discovery of Novel Hub Genes Across Breast, Ovarian, and Prostate Cancers

Breast, ovarian, and prostate cancers are amongst the most prevalent diagnosed cancers annually. These cancers are classified into subtypes based on specific characteristics, however, there are some common underlying aetiological features such as hormone receptors. Few studies have investigated such common features. Here, breast, ovarian and prostate cancers were analysed to identify cross-cancer gene/s that could potentially be used as biomarkers and/or treatment targets. A novel method/workflow using R programming was developed to integrate publicly available microarray tissue (RNA) data to increase sensitivity/sample numbers. Significantly upregulated differentially expressed genes (DEGs) that were identified, were compared between the three cancers using classifications identified in literature. Two analyses were conducted comparing subtypes: 1) histological breast cancer, ovarian cancer tissue location, and prostate cancer Gleason grade group; 2) breast cancer molecular, ovarian epithelial, and prostate cancer Gleason score. Three cross-cancer significantly upregulated DEGs, HMMR, CENPE, and STIL were identified in both analyses: 1) HMMR Log2FC = 1.37 (P = 1.29E-10), CENPE Log2FC = 1.12 (P = 6.62E-08), and STIL Log2FC = 1.07 (P = 4.38E-08); 2) HMMR Log2FC = 1.64 (P = 2.23E-04), CENPE Log2FC = 1.42 (P = 5.82E-05), STIL Log2FC = 1.35 (P = 7.82E-06). HMMR, CENPE, and STIL were significantly associated with reduced survival times (using 95% confidence interval) in recurrence free survival (Hazard Ratio (HR) = 1.18 - 1.84, P = 1E-16 - 0.012), and in overall survival (HR = 1.29 - 2.10, P = 7.1E-03 - 5.2E-09). Network analysis identified HMMR, CENPE, and STIL as hub genes. Gene ontology (GO) and literature search identified them as functioning in G2/M phase cell cycle transition, indicating a shared mechanism/s of action. Therefore, the hub genes (HMMR, CENPE, STIL) termed ‘HCS three-gene signature’ were identified as potential biomarkers and treatment targets in breast, ovarian, or prostate cancers, regardless of subtype