Star formation bursts in isolated spiral galaxies

We study the response of the gaseous component of a galactic disc to the time dependent potential generated by N-body simulations of a spiral galaxy. The results show significant variation of the spiral structure of the gas which might be expected to result in significant fluctuations in the Star Formation Rate (SFR). Pronounced local variations of the SFR are anticipated in all cases. Bursty histories for the global SFR, however, require that the mean surface density is much less (around an order of magnitude less) than the putative threshold for star formation. We thus suggest that bursty star formation histories, normally attributed to mergers and/or tidal interactions, may be a normal pattern for gas poor isolated spiral galaxies.Comment: 7 pages, 7 figures To be published in Monthly Notices Roy. Astr. So

Scheduling of users with Markovian time-varying transmission rates

We address the problem of developing a well-performing and implementable scheduler of users with wireless connection to the base station. The main feature of such real-life systems is that the quality conditions of the user channels are time-varying, which turn into the time-varying transmission rate due to different modulation and coding schemes. We assume that this phenomenon follows a Markovian law and most of the discussion is dedicated to the case of three quality conditions of each user, for which we characterize an optimal index policy and show that threshold policies (of giving higher priority to users with higher transmission rate) are not necessarily optimal. For the general case of arbitrary number of quality conditions we design a scheduler and propose its two practical approximations, and illustrate the performance of the proposed index-based schedulers and existing alternatives in a variety of simulation scenarios

Development of Prognosis in Palliative care Study (PiPS) predictor models to improve prognostication in advanced cancer: prospective cohort study

OBJECTIVE: To develop a novel prognostic indicator for use in patients with advanced cancer that is significantly better than clinicians' estimates of survival. DESIGN: Prospective multicentre observational cohort study. SETTING: 18 palliative care services in the UK (including hospices, hospital support teams, and community teams). PARTICIPANTS: 1018 patients with locally advanced or metastatic cancer, no longer being treated for cancer, and recently referred to palliative care services. MAIN OUTCOME MEASURES: Performance of a composite model to predict whether patients were likely to survive for "days" (0-13 days), "weeks" (14-55 days), or "months+" (>55 days), compared with actual survival and clinicians' predictions. RESULTS: On multivariate analysis, 11 core variables (pulse rate, general health status, mental test score, performance status, presence of anorexia, presence of any site of metastatic disease, presence of liver metastases, C reactive protein, white blood count, platelet count, and urea) independently predicted both two week and two month survival. Four variables had prognostic significance only for two week survival (dyspnoea, dysphagia, bone metastases, and alanine transaminase), and eight variables had prognostic significance only for two month survival (primary breast cancer, male genital cancer, tiredness, loss of weight, lymphocyte count, neutrophil count, alkaline phosphatase, and albumin). Separate prognostic models were created for patients without (PiPS-A) or with (PiPS-B) blood results. The area under the curve for all models varied between 0.79 and 0.86. Absolute agreement between actual survival and PiPS predictions was 57.3% (after correction for over-optimism). The median survival across the PiPS-A categories was 5, 33, and 92 days and survival across PiPS-B categories was 7, 32, and 100.5 days. All models performed as well as, or better than, clinicians' estimates of survival. CONCLUSIONS: In patients with advanced cancer no longer being treated, a combination of clinical and laboratory variables can reliably predict two week and two month survival

Scattered M3–4 Slip Bursts Within Creep Events on the San Andreas Fault

Scientists have observed the surface expression of creep events along the San Andreas Fault since the 1960s. However, the evolution of slip at depth has been examined relatively little. So here we probe that deep slip by analyzing strain observations just before and during hours‐ to day‐long creep events at the northern end of the creeping section of the San Andreas Fault. We identify 71 strain offsets that are likely produced by few‐hour bursts of slip at depth. Then, we grid search to determine the location, depth, and magnitude of these slip bursts. We find that the slip bursts occur at a range of along‐strike locations, from 0 to 7 km away from the surface slip observations. Slip occurs at depths from 0 to 10 km; 42%–55% of the bursts are likely below 4 km depth. The bursts typically have moments equivalent to M w 3.2–4.1 earthquakes. These findings suggest that creep events are not just small shallow events; they are relatively large events that nucleate at significant depths and could play a prominent role in the slip dynamics of the creeping section

An investigation of the cross-language transfer of reading skills: Evidence from a study in Nigerian Government Primary Schools

This paper investigates the linguistic interdependence of grade 3 children studying in government primary schools in northern Nigeria who are learning to read in Hausa (L1) and English (L2) simultaneously. There are few studies in the African context that consider linguistic interdependence and the bidirectional influences of literacy skills in multilingual contexts. To do so a total of 2,328 grade 3 children were tested on their Hausa and English letter sound knowledge (phonemes) and reading decoding skills (word) after participating in a two-year English structured reading intervention programme as part of their school day. In grade 4 these children will become English immersion learners, with English becoming the medium of instruction. Carrying out bivariate correlations we find a large and strongly positively significant correlation between L1 and L2 test scores. Concerning bidirectionality a feedback path model illustrates that L1 word predicts L2 word and vice versa. Multi-level modelling is then used to consider the variation in test scores. Almost two thirds of the variation in the word score is attributable to the pupil level and one third to the school level. Hausa word score is significantly predicted through Hausa sound and English word score. English word score is significantly predicted through Hausa word and English sound score. The findings have implications for language policy and classroom instruction showing the importance of cross-language transfer between reading skills. The overall results support bidirectionality and linguistic interdependence

MesobanK UK: an international mesothelioma bioresource.

Malignant pleural mesothelioma causes the greatest societal burden of all the asbestos-related diseases. Progress in better understanding tumour biology will be facilitated by the availability of quality-assured annotated tissue. MesobanK has been created to establish a bioresource of pleural mesothelioma tissue linked to detailed anonymised clinical data. When complete, the bioresource will comprise a 750-patient tissue microarray and prospectively collected tissue, blood and pleural fluid from 300 patients with mesothelioma. Twenty-six new cell lines have also been developed. MesobanK meets all appropriate ethical and regulatory procedures and has recently opened to requests for tissue and data.RCR and DMR are part funded by the Cambridge Biomedical Research Centre and the Cambridge Cancer Centre. RCR is also funded by the NIHR Clinical Research Network: Eastern.This is the final version of the article. It first appeared from BMJ via http://dx.doi.org/10.1136/thoraxjnl-2015-20749

Prospects for rapid deceleration of small molecules by optical bichromatic forces

We examine the prospects for utilizing the optical bichromatic force (BCF) to greatly enhance laser deceleration and cooling for near-cycling transitions in small molecules. We discuss the expected behavior of the BCF in near-cycling transitions with internal degeneracies, then consider the specific example of decelerating a beam of calcium monofluoride molecules. We have selected CaF as a prototype molecule both because it has an easily-accessible near-cycling transition, and because it is well-suited to studies of ultracold molecular physics and chemistry. We also report experimental verification of one of the key requirements, the production of large bichromatic forces in a multi-level system, by performing tests in an atomic beam of metastable helium.Comment: 11 pages, 6 figures, revised version, to be published in Physical Review