Lanthanides and other spectral oddities in a Centauri

Context: There is considerable interest in the helium variable a Cen as a bridge between helium-weak and helium-strong CP stars. Aims: We investigate Ce III and other possible lanthanides in the spectrum the of hottest chemically peculiar (CP) star in which these elements have been found. A {Kr II line appears within a broad absorption which we suggest may be due to a high-level transition in C II. Methods: Wavelengths and equivalent widths are measured on high-resolution UVES spectra, analyzed, and their phase-variations investigated. Results: New, robust identifications of Ce III and Kr II are demonstrated. Nd III is likely present. A broad absorption near 4619[A] is present at all phases of a Cen, and in some other early B stars. Conclusions: The presence of lanthanides in a Cen strengthens the view that this star is a significant link between the cooler CP stars and the hotter helium-peculiar stars. Broad absorptions in a Cen are not well explained.Comment: Research Note accepted by Astronomy and Astrophysics; 4 pages, 4 Figs. 2 Table

Preparing potential teachers for the transition from employment to teacher training: an evaluative case study of a Maths Enhancement Course

In response to a UK government drive to improve maths teaching in schools, the South West London Maths Enhancement Course (MEC) has been set up though collaboration between three Higher Education institutions (HEIs) to provide an efficient route for non maths graduates in employment to upgrade their subject knowledge and give a smooth transition into teacher training (PGCE). An evaluation of the scheme, measured against Teacher Development Agency (TDA) objectives and success criteria agreed by university staff, involved thematic analysis of focus group discussions and interviews with students and staff during both the MEC and PGCE courses. This has revealed a high level of satisfaction and success related to a number of underlying issues, particularly around student recruitment, curriculum design, peer support and staff collaboration. The model offers an example of practice transferable to a range of programmes aimed at supporting students in the transition between levels and institutions

The added value of longitudinal black-blood cardiovascular magnetic resonance angiography in the cross sectional identification of carotid atherosclerotic ulceration

<p>Abstract</p> <p>Background</p> <p>Carotid atherosclerotic ulceration is a significant source of stroke. This study evaluates the efficacy of adding longitudinal black-blood (BB) cardiovascular magnetic resonance (CMR) angiography to cross-sectional CMR images in the identification of carotid atherosclerotic ulceration.</p> <p>Methods</p> <p>Thirty-two subjects (30 males and two females with ages between 48 and 83 years) scheduled for carotid endarterectomy were imaged on a 1.5T GE Signa scanner using multisequence [3D time-of-flight, T1, proton density, T2, contrast enhanced T1], cross-sectional CMR images and longitudinal BB CMR angiography (0.625 × 0.625 mm/pixel). Two rounds of review (round 1: cross-sectional CMR images alone and round 2: cross-sectional CMR images plus longitudinal BB CMR angiography) were conducted for the presence and volume measurements of ulceration. Ulceration was defined as a distinct depression into the plaque containing blood flow signal on cross-sectional CMR and longitudinal BB CMR angiography.</p> <p>Results</p> <p>Of the 32 plaques examined by histology, 17 contained 21 ulcers. Using the longitudinal BB CMR angiography sequence in addition to the cross-sectional CMR images in round 2, the sensitivity improved to 80% for ulcers of at least 6 mm³in volume by histology and 52.4% for all ulcers, compared to 30% and 23.8% in round 1, respectively. There was a slight decline in specificity from 88.2% to 82.3%, though both the positive and negative predictive values increased modestly from 71.4% to 78.6% and from 48.4% to 58.3%, respectively.</p> <p>Conclusion</p> <p>The addition of longitudinal BB CMR angiography to multisequence cross-sectional CMR images increases accuracy in the identification of carotid atherosclerotic ulceration.</p

Cost-effectiveness of trifluridine/tipiracil for previously treated metastatic colorectal cancer in England and Wales

Background Treatment options at third-line and beyond for patients with late-line metastatic colorectal cancer (mCRC) are limited, and outcomes are poor with best supportive care (BSC). This study investigated the cost-effectiveness of trifluridine/tipiracil and regorafenib relative to BSC alone in patients with mCRC who have been previously treated with, or are not considered candidates for, standard chemotherapies. Materials and Methods A partitioned survival model was constructed to assess the lifetime costs and benefits accrued by patients. Clinical data were derived from the pivotal phase III (Randomized, Double-Blind, Phase 3 Study of TAS-102 plus Best Supportive Care [BSC] versus Placebo plus BSC in Patients with Metastatic Colorectal Cancer Refractory to Standard Chemotherapies [RECOURSE]) and supporting phase II (J003-10040030) randomized controlled trial of trifluridine/tipiracil + BSC versus placebo + BSC, as well as the phase III Colorectal Cancer Treated With Regorafenib or Placebo After Failure of Standard Therapy (CORRECT) randomized controlled trial of regorafenib, and were extrapolated to estimate lifetime outcomes. Costs were taken from published sources, and health effects sourced from previous mCRC studies. Results Trifluridine/tipiracil was associated with a 0.27 incremental life year versus BSC alone, which corresponds to a 0.17 quality-adjusted life year gain. The incremental cost of treatment with trifluridine/tipiracil was £8,479, resulting in an incremental cost-effectiveness ratio of £51,194 per quality-adjusted life year gained. Trifluridine/tipiracil was shown to dominate regorafenib (improve outcomes with reduced costs). Sensitivity analyses showed principal areas of uncertainty were survival estimates and patient utility. Conclusions The results show that trifluridine/tipiracil is more clinically and cost-effective than regorafenib, with clinical outcomes greatly exceeding those for patients treated with BSC alone. Based on the results of the analysis, trifluridine/tipiracil offers an important new treatment option for patients with mCRC maintaining good performance status at the end of life

Ancient Migratory Events in the Middle East: New Clues from the Y-Chromosome Variation of Modern Iranians

Knowledge of high resolution Y-chromosome haplogroup diversification within Iran provides important geographic context regarding the spread and compartmentalization of male lineages in the Middle East and southwestern Asia. At present, the Iranian population is characterized by an extraordinary mix of different ethnic groups speaking a variety of Indo-Iranian, Semitic and Turkic languages. Despite these features, only few studies have investigated the multiethnic components of the Iranian gene pool. In this survey 938 Iranian male DNAs belonging to 15 ethnic groups from 14 Iranian provinces were analyzed for 84 Y-chromosome biallelic markers and 10 STRs. The results show an autochthonous but non-homogeneous ancient background mainly composed by J2a sub-clades with different external contributions. The phylogeography of the main haplogroups allowed identifying post-glacial and Neolithic expansions toward western Eurasia but also recent movements towards the Iranian region from western Eurasia (R1b-L23), Central Asia (Q-M25), Asia Minor (J2a-M92) and southern Mesopotamia (J1-Page08). In spite of the presence of important geographic barriers (Zagros and Alborz mountain ranges, and the Dasht-e Kavir and Dash-e Lut deserts) which may have limited gene flow, AMOVA analysis revealed that language, in addition to geography, has played an important role in shaping the nowadays Iranian gene pool. Overall, this study provides a portrait of the Y-chromosomal variation in Iran, useful for depicting a more comprehensive history of the peoples of this area as well as for reconstructing ancient migration routes. In addition, our results evidence the important role of the Iranian plateau as source and recipient of gene flow between culturally and genetically distinct population

Activation of the innate immune receptor Dectin-1 upon formation of a 'phagocytic synapse'.

Innate immune cells must be able to distinguish between direct binding to microbes and detection of components shed from the surface of microbes located at a distance. Dectin-1 (also known as CLEC7A) is a pattern-recognition receptor expressed by myeloid phagocytes (macrophages, dendritic cells and neutrophils) that detects β-glucans in fungal cell walls and triggers direct cellular antimicrobial activity, including phagocytosis and production of reactive oxygen species (ROS). In contrast to inflammatory responses stimulated upon detection of soluble ligands by other pattern-recognition receptors, such as Toll-like receptors (TLRs), these responses are only useful when a cell comes into direct contact with a microbe and must not be spuriously activated by soluble stimuli. In this study we show that, despite its ability to bind both soluble and particulate β-glucan polymers, Dectin-1 signalling is only activated by particulate β-glucans, which cluster the receptor in synapse-like structures from which regulatory tyrosine phosphatases CD45 and CD148 (also known as PTPRC and PTPRJ, respectively) are excluded (Supplementary Fig. 1). The 'phagocytic synapse' now provides a model mechanism by which innate immune receptors can distinguish direct microbial contact from detection of microbes at a distance, thereby initiating direct cellular antimicrobial responses only when they are required

Determining the Physical Properties of the B Stars I. Methodology and First Results

We describe a new approach to fitting the UV-to-optical spectra of B stars to model atmospheres and present initial results. Using a sample of lightly reddened stars, we demonstrate that the Kurucz model atmospheres can produce excellent fits to either combined low dispersion IUE and optical photometry or HST FOS spectrophotometry, as long as the following conditions are fulfilled: 1) an extended grid of Kurucz models is employed, 2) the IUE NEWSIPS data are placed on the FOS absolute flux system using the Massa & Fitzpatrick (1999) transformation, and 3) all of the model parameters and the effects of interstellar extinction are solved for simultaneously. When these steps are taken, the temperatures, gravities, abundances and microturbulence velocities of lightly reddened B0-A0 V stars are determined to high precision. We also demonstrate that the same procedure can be used to fit the energy distributions of stars which are reddened by any UV extinction curve which can be expressed by the Fitzpatrick & Massa (1990) parameterization scheme. We present an initial set of results and verify our approach through comparisons with angular diameter measurements and the parameters derived for an eclipsing B star binary. We demonstrate that the metallicity derived from the ATLAS 9 fits to main sequence B stars is essentially the Fe abundance. We find that a near zero microturbulence velocity provides the best-fit to all but the hottest or most luminous stars (where it may become a surrogate for atmospheric expansion), and that the use of white dwarfs to calibrate UV spectrophotometry is valid.Comment: 17 pages, including 2 pages of Tables and 6 pages of Figures. Astrophysical Jounral, in pres

Cygnus X-3 with ISO: investigating the wind

We observed the energetic binary Cygnus X-3 in both quiescent and flaring states between 4 and 16 microns using the ISO satellite. We find that the quiescent source shows the thermal free-free spectrum typical of a hot, fast stellar wind, such as from a massive helium star. The quiescent mass-loss rate due to a spherically symmetric, non-accelerating wind is found to be in the range 0.4-2.9 x 10E-4 solar masses per year, consistent with other infrared and radio observations, but considerably larger than the 10E-5 solar masses per year deduced from both the orbital change and the X-ray column density. There is rapid, large amplitude flaring at 4.5 and 11.5 microns at the same time as enhanced radio and X-ray activity, with the infrared spectrum apparently becoming flatter in the flaring state. We believe non-thermal processes are operating, perhaps along with enhanced thermal emission.Comment: Accepted for publication in MNRAS, 11 pages, 6 figure

Is age a barrier to chemotherapy? Rates of treatment in older patients with breast, colon or lung cancer in England in 2014: A national registry study

Background Survival from cancer in older patients is poorer in the UK than other countries with similar health systems and wealth possibly due to undertreatment and increased toxicities in this specific population. This population-based observational study describes factors affecting systemic anticancer treatment (SACT) use in older patients in England. Methods We identified patients aged ≥70 with stage II-III breast cancer, stage III colon cancer and stage IIIB-IV non-small cell lung cancer (NSCLC) diagnosed in 2014 from a dataset collected by the National Health Service in England. We used logistic regression to estimate factors affecting likelihood of receiving SACT and performed separate regression analyses for each disease, adjusting for age, gender, stage at diagnosis, pathological features, performance status, Charlson comorbidity index, ethnicity and socioeconomic group. We assessed 2-year overall survival (OS) using Kaplan-Meier method. Case mix adjusted treatment rates and workload volume were calculated at hospital level and presented using funnel plots, stratified by age groups (<70 and ≥70) to allow for assessment of variation between centres. Results 36892 patients were identified: 19879 with stage II-III breast cancer, 5292 with stage III colon cancer and 11721 with stage IIIB-IV NSCLC. Patients over 70 were less likely to receive SACT compared to those aged under 70: breast 11.7% vs 64.6%, p < 0.001; colon 37.4% vs 79%, p < 0.001; NSCLC 33.5% vs 60.2%, p < 0.001. 2-year OS for patients receiving SACT was similar for patients aged ≥70 and <70: breast 91.5% (95% CI: 89.3%-93.2%) vs 96.4% (95% CI: 95.9%-96.7%); colon 84.8% (95% CI: 82.6%-86.8%) vs 88.3% (95% CI: 86.7%-89.8%); NSCLC 16.7% (95% CI: 15.1%-18.4%) vs 19.8% (95%CI: 18.5%-21.1%). Patients receiving SACT had better OS than those untreated. SACT rates varied widely between hospitals after adjusting for case-mix across all ages. Conclusions Our study suggests that several factors affect the likelihood of receiving SACT but after adjusting for these, age remains determinant. Identifying hospitals with significantly lower SACT rates should prompt local review of multidisciplinary team practice

Periodic and Quasiperiodic Motion of an Elongated Microswimmer in Poiseuille Flow

We study the dynamics of a prolate spheroidal microswimmer in Poiseuille flow for different flow geometries. When moving between two parallel plates or in a cylindrical microchannel, the swimmer performs either periodic swinging or periodic tumbling motion. Although the trajectories of spherical and elongated swimmers are qualitatively similar, the swinging and tumbling frequency strongly depends on the aspect ratio of the swimmer. In channels with reduced symmetry the swimmers perform quasiperiodic motion which we demonstrate explicitely for swimming in a channel with elliptical cross section