Chandra Measurements of a Complete Sample of X-ray Luminous Galaxy Clusters: the Gas Mass Fraction

We present Chandra X-ray measurements of the gas mass fraction out to r500 for a complete sample of the 35 most luminous clusters from the Brightest Cluster Sample and the Extended Brightest Cluster Sample at redshift z=0.15-0.30. The sample includes relaxed and unrelaxed clusters, and the data were analysed independently using two pipelines and two different models for the gas density and temperature. We measure an average of fgas(r500) = 0.163 +/- 0.032, which is in agreement with the cosmic baryon fraction (Omega_b / Omega_M = 0.167 +/- 0.006) at the 1-sigma level, after adding the stellar baryon fraction. Earlier studies reported gas mass fractions significantly lower than the cosmic baryon fraction at r500, and in some cases higher values that are consistent with the cosmic baryon fraction towards the virial radius.In this paper we show that the most X-ray luminous clusters in the redshift range z=0.15-0.30 have a gas mass fraction that is consistent with the cosmic value at r500.Comment: MNRAS submitted, comments welcome; 23 pages, 57 figure

Evidence Inference 2.0: More Data, Better Models

How do we most effectively treat a disease or condition? Ideally, we could consult a database of evidence gleaned from clinical trials to answer such questions. Unfortunately, no such database exists; clinical trial results are instead disseminated primarily via lengthy natural language articles. Perusing all such articles would be prohibitively time-consuming for healthcare practitioners; they instead tend to depend on manually compiled systematic reviews of medical literature to inform care. NLP may speed this process up, and eventually facilitate immediate consult of published evidence. The Evidence Inference dataset was recently released to facilitate research toward this end. This task entails inferring the comparative performance of two treatments, with respect to a given outcome, from a particular article (describing a clinical trial) and identifying supporting evidence. For instance: Does this article report that chemotherapy performed better than surgery for five-year survival rates of operable cancers? In this paper, we collect additional annotations to expand the Evidence Inference dataset by 25\%, provide stronger baseline models, systematically inspect the errors that these make, and probe dataset quality. We also release an abstract only (as opposed to full-texts) version of the task for rapid model prototyping. The updated corpus, documentation, and code for new baselines and evaluations are available at http://evidence-inference.ebm-nlp.com/.Comment: Accepted as workshop paper into BioNLP Updated results from SciBERT to Biomed RoBERT

Machines on Genes: Enzymes that Make, Break and Move DNA and RNA

As the vital information repositories of the cell, the nucleic acids DNA and RNA pose many challenges as enzyme substrates. To produce, maintain and repair DNA and RNA, and to extract the genetic information that they encode, a battery of remarkable enzymes has evolved, which includes translocases, polymerases/replicases, helicases, nucleases, topoisomerases, transposases, recombinases, repair enzymes and ribosomes. An understanding of how these enzymes function is essential if we are to have a clear view of the molecular biology of the cell and aspire to manipulate genomes and gene expression to our advantage. To bring together scientists working in this fast-developing field, the Biochemical Society held a Focused Meeting, ‘Machines on Genes: Enzymes that Make, Break and Move DNA and RNA’, at Robinson College, University of Cambridge, U.K., in August 2009. The present article summarizes the research presented at this meeting and the reviews associated with the talks which are published in this issue of Biochemical Society Transactions

Barriers to participation in education and training

This study explores the barriers and constraints young people currently face when deciding what to do at the end of their compulsory schooling in Year 11. The study conducted by the NFER, working in partnership with Triangle and QA Research, included a survey of 2029 young people who completed Year 11 in either 2008 or 2009 conducted between August and October 2009. This survey was supplemented by interviews with booster samples of 519 young people across specific sub-groups and 102 parent interviews

Mainstreaming gender in sanitation

The Integrated Water and Environmental Sanitation (IWES) Project is implemented in the Indian state of Jharkhand by the local government and seven NGOs. Funded by SIDA, and coordinated by UNICEF, the project promotes sanitation in rural East Singhbhum district. There is increasing acknowledgement that gender mainstreaming is essential if development projects are to address the strategic needs of women. In East Singhbhum, though, it has proved difficult to engage women in decision- making processes. Research was therefore undertaken to investigate local gender dynamics and their underlying causes, in the context of the sanitation element of the IWES Project. Fieldwork was carried out under UNICEF’s Internship Scheme over a period of 3 months in 2001. The study areas included in three tribal villages (Bangora, Kuilisuta and Korashole) in Musabani Block, and two villages in Phulwarisarif Block, near Patna, where UNICEF is supporting development through Convergent Community Action (CCA). The research was greatly assisted by the NGOs SEEDS and IDF

MIRACLE: MIcRo-ArChitectural Leakage Evaluation

In this paper, we describe an extensible experimental infrastructure for evaluating the micro-architectural leakage, based on power consumption, that stems from a physical device. Building on existing literature, we use it to systematically study 14 different devices, which span 4 different instruction set architectures and 4 different vendors. The study allows a characterisation of each device with respect to any leakage effects stemming from sources within the micro-architectural implementation. We use it, for example, to identify and document several novel leakage effects (e.g., due to speculative instruction execution), and scenarios where an assumption about leakage is non-portable between different yet compatible devices. Ours is the widest study of its kind we are aware of, and highlights a range of challenges with respect to 1) the design, implementation, and evaluation of, e.g., masking schemes, 2) construction of accurate leakage models, and 3) selection of suitable devices for experimental research. For example, in relation to 1), we cast further doubt on whether a given device upholds the assumptions required by a given masking scheme; in relation to 2), we conclude that (statistical or formal) device leakage models must include information about the micro-architecture being modelled; in relation to 3), we claim the near mono-culture of devices that dominates existing literature is insufficient to support general claims regarding leakage. This is particularly important in the context of the FIPS 140-3 standard for non-invasive side-channel evaluation

Lifts of convex sets and cone factorizations

In this paper we address the basic geometric question of when a given convex set is the image under a linear map of an affine slice of a given closed convex cone. Such a representation or 'lift' of the convex set is especially useful if the cone admits an efficient algorithm for linear optimization over its affine slices. We show that the existence of a lift of a convex set to a cone is equivalent to the existence of a factorization of an operator associated to the set and its polar via elements in the cone and its dual. This generalizes a theorem of Yannakakis that established a connection between polyhedral lifts of a polytope and nonnegative factorizations of its slack matrix. Symmetric lifts of convex sets can also be characterized similarly. When the cones live in a family, our results lead to the definition of the rank of a convex set with respect to this family. We present results about this rank in the context of cones of positive semidefinite matrices. Our methods provide new tools for understanding cone lifts of convex sets.Comment: 20 pages, 2 figure

Exploring the use of combined action observation and motor imagery for improving eye-hand coordination in children with developmental coordination disorder

This thesis documents a series of studies that are the first to demonstrate the efficacy of combined action observation and motor imagery (AOMI) for improving eye-hand coordination and task performance in individuals with and without developmental coordination disorder (DCD). First, a comparison of the effectiveness of AOMI, observing to imitate, and passive observation training interventions is reported. The results indicated that, in comparison to a control group, AOMI training produced a statistically significant increase in both task performance and eye-hand coordination, but no such improvements were found following observing to imitate or passive observation instructions. These findings suggest that AOMI facilitated the development of proactive eye movements that enhanced task performance. Second, the eye-hand coordination and task performance of children with and without DCD on a novel visuomotor task was explored. The findings from this study, in accordance with similar studies, indicated that the novel visuomotor task used in the study might have lacked the necessary complexity required to find significant differences in visuomotor performance between children with and without DCD. Third, the development of a new visuomotor task of higher complexity and suitable for use in an AOMI training intervention for children with DCD is reported. Analysis indicated a higher number of trials were required before performance plateaued and the best task performers adopted a distinct movement pattern. These results confirmed that the new task required a longer period of adaptation and supported the application of this task with DCD children in an AOMI training intervention. In the final study, the effects of an AOMI training intervention upon eye-hand coordination and performance in children with DCD are reported. Analysis of the data revealed that the AOMI training produced significant improvements in completion time and gaze control. It was concluded that children with DCD may benefit from AOMI training as the technique may aid their ability to update internal models of movement. This series of studies was the first to explore the effectiveness of AOMI training for improving eye-hand coordination and extend those findings to a clinical population. The results of these studies describe a conclusion that AOMI facilitates the development of proactive gaze, which in turn assists performance

The Structure of High Strehl Ratio Point-Spread Functions

We describe the symmetries present in the point-spread function (PSF) of an optical system either located in space or corrected by an adaptive o to Strehl ratios of about 70% and higher. We present a formalism for expanding the PSF to arbitrary order in terms of powers of the Fourier transform of the residual phase error, over an arbitrarily shaped and apodized entrance aperture. For traditional unapodized apertures at high Strehl ratios, bright speckles pinned to the bright Airy rings are part of an antisymmetric perturbation of the perfect PSF, arising from the term that is first order in the residual phase error. There are two symmetric second degree terms. One is negative at the center, and, like the first order term, is modulated by the perfect image's field strength -- it reduces to the Marechal approximation at the center of the PSF. The other is non-negative everywhere, zero at the image center, and can be responsible for an extended halo -- which limits the dynamic range of faint companion detection in the darkest portions of the image. In regimes where one or the other term dominates the speckles in an image, the symmetry of the dominant term can be exploited to reduce the effect of those speckles, potentially by an order of magnitude or more. We demonstrate the effects of both secondary obscuration and pupil apodization on the structure of residual speckles, and discuss how these symmetries can be exploited by appropriate telescope and instrument design, observing strategies, and filter bandwidths to improve the dynamic range of high dynamic range AO and space-based observations. Finally, we show that our analysis is relevant to high dynamic range coronagraphy.Comment: Accepted for publication in ApJ; 20 pages, 4 figure