The kinetic theory of sound propagation in binary gaseous mixtures.

We develop a theory for the study of the absorption and dispersion of a sound wave propagating in a binary mixture of gases by using both the 13-moment approximation and the Navier - Stokes theory. This general theory is valid for a mixture of any two monatomic gases, however, we limit our study to the mixture of helium and argon. After lengthy mathematical formulation we obtain a set of linear equations in the general eigenvalue - eigenvector form. Using numerical methods to solve the eigenvalue equation, we compute the absorption and dispersion. We compare the absorption calculated by both the 13-moment approximation and the Navier - Stokes theory with experimental data for mixtures containing 5%, 10%, 25%, 50% and 75% argon. Both theories give values which compare favorably with experiment for low and mid-range values of frequency/pressure. The Navier - Stokes absorption values are consistently closer to experiment for higher values of f/p. For the 50% argon mixture, we find that the 13-moment absorption curve peaks sharply for f/p ˜ 280. The corresponding dispersion curve dips at the same value. The Navier - Stokes theory yields neither of these features. For each of the remaining cases, the dispersion curves for the 13-moment approximation start at ˜ and decrease until leveling off. The Navier - Stokes dispersion curves also start at 1 but decrease steadily, with the final dispersion value being greater than the corresponding absorption by .01

The impact of endoparasitic Wolbachia on the evolution of reproductive barriers during speciation in Drosophila ananassae from Southeast Asia and the South Pacific

There is still much work to be done in Biology to study and understand the mechanisms that drive the generation of new species. The model organism Drosophila ananassae represents and ideal model to untangle these issues. Previous genetic and mate discrimination studies of D. ananassae showed evidence that populations in Southeast Asia, and the South Pacific may be at a nascent stage of speciation (Schug et al. 2007, 2008). Subsequent preliminary studies demonstrated a potential postmating isolation barrier may exist between Bogor, Indonesia isofemale line 13 (BOG13) and females from Trinity Beach, Australia isofemale line 12 (TB12), which when hybridized and backcrossed to BOG13 females showed a decrease in offspring production. This may reflect a genetic isolation barrier, or alternatively, the effects of infection of one population or the other with endoparasite Wolbachia which is known in other organisms to cause postmating reproductive barriers. My study tested the hypothesis that the postmating barrier present between these two populations is driven by Wolbachia infection. I found that TB12 was infected with Wolbachia and BOG13 was not. A full reciprocal backcross preformed between these isofemale lines, and replicate using a TB12 isofemale line cured of the Wolbachia infection, revealed results consistent with Wolbachia-induced cytoplasmic incompatibilities (CI), that were removed when cured of the Wolbachia infection. A screen of additional strains previously shown to have high levels of mate discrimination showed the possibility that Wolbachia infection may have influenced the evolution of postmating reproductive barriers in additional populations of D. ananassae from throughout Southeast Asia and South Pacific. However, my mate discrimination experiments using infected versus cured isofemale lines from Bogor, Indonesia and Trinity Beach, Australia indicated that it is unlikely that Wolbachia infections directly influence mate discrimination behaviors, but are likely having an influence on postmating reproduction. Taken together this suggests that Wolbachia infections in populations of D. ananassae throughout its range in Southeast Asia and the South Pacific may have a significant influence on population divergence and speciation

Blocks with transitive fusion systems

Suppose that all nontrivial subsections of a $p$-block $B$ are conjugate (where $p$ is a prime). By using the classification of the finite simple groups, we prove that the defect groups of $B$ are either extraspecial of order $p^3$ with $p \in \{3,5\}$ or elementary abelian

CT head reporting by radiographers: results of an accredited postgraduate programme

Aim: To evaluate the results of the summative objective structured examination (OSE) for the first four cohorts of radiographers (n ¼ 24) undertaking an accredited postgraduate course in reporting computer tomography (CT) head examinations. Method: The construction of a summative OSE contained twenty five CT head examinations that incorporated 1:1 normal to abnormal pathological examples. All cases were blind reported by three consultant radiologists to produce a valid reference standard report for comparison with the radiographer's interpretation. The radiographers (n ¼ 24) final reports (n ¼ 600) were analysed to determine the sensitivity, specificity and agreement values and concordance for the four cohorts. Results: The four cohorts (2007e2013) of postgraduate radiography students' collective OSE results established a mean sensitivity rate of 99%, specificity 95% and agreement concordance rates of 90%. The final grades indicate that within an academic environment, trained radiographers possess high levels of diagnostic performance accuracy in the interpretation of CT head examinations

The impact of data from remote measurement technology on the clinical practice of healthcare professionals in depression, epilepsy and multiple sclerosis: survey

BackgroundA variety of smartphone apps and wearables are available both to help patients monitor their health and to support health care professionals (HCPs) in providing clinical care. As part of the RADAR-CNS consortium, we have conducted research into the application of wearables and smartphone apps in the care of people with multiple sclerosis, epilepsy, or depression.MethodsWe conducted a large online survey study to explore the experiences of HCPs working with patients who have one or more of these conditions. The survey covered smartphone apps and wearables used by clinicians and their patients, and how data from these technologies impacted on the respondents' clinical practice. The survey was conducted between February 2019 and March 2020 via a web-based platform. Detailed statistical analysis was performed on the answers.ResultsOf 1009 survey responses from HCPs, 1006 were included in the analysis after data cleaning. Smartphone apps are used by more than half of responding HCPs and more than three quarters of their patients use smartphone apps or wearable devices for health-related purposes. HCPs widely believe the data that patients collect using these devices impacts their clinical practice. Subgroup analyses show that views on the impact of this data on different aspects of clinical work varies according to whether respondents use apps themselves, and, to a lesser extent, according to their clinical setting and job role.ConclusionsUse of smartphone apps is widespread among HCPs participating in this large European survey and caring for people with epilepsy, multiple sclerosis and depression. The majority of respondents indicate that they treat patients who use wearables and other devices for health-related purposes and that data from these devices has an impact on clinical practice

AFROC analysis of reporting radiographer’s performance in CT head interpretation

Aim: A preliminary small scale study to assess the diagnostic performance of a limited group of reporting radiographers and consultant radiologists in clinical practice undertaking computer tomography (CT) head interpretation . Method: A multiple reader multiple case (MRMC) alternative free response receiver operating characteristic (AFROC) methodology was applied. Utilising an image bank of 30 CT head examinations, with a 1:1 ratio of normal to abnormal cases. A reference standard was established by double reporting the original reports using two additional independent consultant radiologists with arbitration of discordance by the researcher. Twelve observers from six southern National Health Service (NHS) trusts were invited to participate. The results were compared for accuracy, agreement, sensitivity, specificity. Data analysis used AFROC and area under the curve (AUC) with standard error. Results: The reporting radiographers results demonstrated a mean sensitivity rate of 88.7% (95% CI 82.3 to 95.1%), specificity 95.6% (96% CI 90.1 to 100%) and accuracy of 92.2% (95% CI 89.3 to 95%). The consultant radiologists mean sensitivity rate was 83.35% (95% CI 80 to 86.7%), specificity 90% (95% CI 86.7 to 93.3%) and accuracy of 86.65% (95% CI 83.3 to 90%). Observer performance between the two groups was compared with AFROC, AUC, and standard error analysis (p=0.94, SE 0.202). Conclusion: The findings of this research indicate that within a limited study, a small group of reporting radiographers demonstrated high levels of diagnostic accuracy in the interpretation of CT head examinations that was equivalent to a small selection of consultant radiologists

International outbreak of Salmonella Oranienburg due to German chocolate

BACKGROUND: This report describes a large international chocolate-associated Salmonella outbreak originating from Germany. METHODS: We conducted epidemiologic investigations including a case-control study, and food safety investigations. Salmonella (S.) Oranienburg isolates were subtyped by the use of pulsed-field gel electrophoresis (PFGE). RESULTS: From 1 October 2001 through 24 March 2002, an estimated excess of 439 S. Oranienburg notifications was registered in Germany. Simultaneously, an increase in S. Oranienburg infections was noted in other European countries in the Enter-net surveillance network. In a multistate matched case-control study in Germany, daily consumption of chocolate (matched odds ratio [MOR]: 4.8; 95% confidence interval [CI]: 1.3–26.5), having shopped at a large chain of discount grocery stores (MOR: 4.2; CI: 1.2–23.0), and consumption of chocolate purchased there (MOR: 5.0; CI: 1.1–47.0) were associated with illness. Subsequently, two brands from the same company, one exclusively produced for that chain, tested positive for S. Oranienburg. In two other European countries and in Canada chocolate from company A was ascertained that also contained S. Oranienburg. Isolates from humans and from chocolates had indistinguishable PFGE profiles. No source or point of contamination was identified. Epidemiological identification of chocolate as a vehicle of infections required two months, and was facilitated by proxy measures. CONCLUSIONS: Despite the use of improved production technologies, the chocolate industry continues to carry a small risk of manufacturing Salmonella-containing products. Particularly in diffuse outbreak-settings, clear associations with surrogates of exposure should suffice to trigger public health action. Networks such as Enter-net have become invaluable for facilitating rapid and appropriate management of international outbreaks

Our friend in the north: the origins, evolution and appeal of the cult of St Duthac of Tain in later Middle Ages

St Duthac of Tain was one of the most popular Scottish saints of the later middle ages. From the late fourteenth century until the reformation devotion to Duthac outstripped that of Andrew, Columba, Margaret and Mungo, and Duthac's shrine in Easter Ross became a regular haunt of James IV (1488-1513) and James V (1513-42). Hitherto historians have tacitly accepted the view of David McRoberts that Duthac was one of several local saints whose emergence and popularity in the fifteenth century was part of a wider self-consciously nationalist trend in Scottish religious practice. This study looks beyond the paradigm of nationalism to trace and explain the popularity of St Duthac from the shadowy origins of the cult to its heyday in the early sixteenth century