Power spectrum multipoles on the curved sky: an application to the 6-degree Field Galaxy Survey

The peculiar velocities of galaxies cause their redshift-space clustering to depend on the angle to the line-of-sight, providing a key test of gravitational physics on cosmological scales. These effects may be described using a multipole expansion of the clustering measurements. Focussing on Fourier-space statistics, we present a new analysis of the effect of the survey window function, and the variation of the line-of-sight across a survey, on the modelling of power spectrum multipoles. We determine the joint covariance of the Fourier-space multipoles in a Gaussian approximation, and indicate how these techniques may be extended to studies of overlapping galaxy populations via multipole cross-power spectra. We apply our methodology to one of the widest-area galaxy redshift surveys currently available, the 6-degree Field Galaxy Survey, deducing a normalized growth rate f*sigma_8(z=0.06) = 0.38 +/- 0.12 in the low-redshift Universe, in agreement with previous analyses of this dataset using different techniques. Our framework should be useful for processing future wide-angle galaxy redshift surveys.Comment: 17 pages, 7 figures, version accepted by MNRA

Better duplicate detection for systematic reviewers: Evaluation of Systematic Review Assistant-Deduplication Module

BACKGROUND: A major problem arising from searching across bibliographic databases is the retrieval of duplicate citations. Removing such duplicates is an essential task to ensure systematic reviewers do not waste time screening the same citation multiple times. Although reference management software use algorithms to remove duplicate records, this is only partially successful and necessitates removing the remaining duplicates manually. This time-consuming task leads to wasted resources. We sought to evaluate the effectiveness of a newly developed deduplication program against EndNote. METHODS: A literature search of 1,988 citations was manually inspected and duplicate citations identified and coded to create a benchmark dataset. The Systematic Review Assistant-Deduplication Module (SRA-DM) was iteratively developed and tested using the benchmark dataset and compared with EndNote’s default one step auto-deduplication process matching on (‘author’, ‘year’, ‘title’). The accuracy of deduplication was reported by calculating the sensitivity and specificity. Further validation tests, with three additional benchmarked literature searches comprising a total of 4,563 citations were performed to determine the reliability of the SRA-DM algorithm. RESULTS: The sensitivity (84%) and specificity (100%) of the SRA-DM was superior to EndNote (sensitivity 51%, specificity 99.83%). Validation testing on three additional biomedical literature searches demonstrated that SRA-DM consistently achieved higher sensitivity than EndNote (90% vs 63%), (84% vs 73%) and (84% vs 64%). Furthermore, the specificity of SRA-DM was 100%, whereas the specificity of EndNote was imperfect (average 99.75%) with some unique records wrongly assigned as duplicates. Overall, there was a 42.86% increase in the number of duplicates records detected with SRA-DM compared with EndNote auto-deduplication. CONCLUSIONS: The Systematic Review Assistant-Deduplication Module offers users a reliable program to remove duplicate records with greater sensitivity and specificity than EndNote. This application will save researchers and information specialists time and avoid research waste. The deduplication program is freely available online

A comparison of the performance of seven key bibliographic databases in identifying all relevant systematic reviews of interventions for hypertension

BACKGROUND: Bibliographic databases are the primary resource for identifying systematic reviews of health care interventions. Reliable retrieval of systematic reviews depends on the scope of indexing used by database providers. Therefore, searching one database may be insufficient, but it is unclear how many need to be searched. We sought to evaluate the performance of seven major bibliographic databases for the identification of systematic reviews for hypertension. METHODS: We searched seven databases (Cochrane library, Database of Abstracts of Reviews of Effects (DARE), Excerpta Medica Database (EMBASE), Epistemonikos, Medical Literature Analysis and Retrieval System Online (MEDLINE), PubMed Health and Turning Research Into Practice (TRIP)) from 2003 to 2015 for systematic reviews of any intervention for hypertension. Citations retrieved were screened for relevance, coded and checked for screening consistency using a fuzzy text matching query. The performance of each database was assessed by calculating its sensitivity, precision, the number of missed reviews and the number of unique records retrieved. RESULTS: Four hundred systematic reviews were identified for inclusion from 11,381 citations retrieved from seven databases. No single database identified all the retrieved systematic reviews for hypertension. EMBASE identified the most reviews (sensitivity 69 %) but also retrieved the most irrelevant citations with 7.2 % precision (Pr). The sensitivity of the Cochrane library was 60 %, DARE 57 %, MEDLINE 57 %, PubMed Health 53 %, Epistemonikos 49 % and TRIP 33 %. EMBASE contained the highest number of unique records (n = 43). The Cochrane library identified seven unique records and had the highest precision (Pr = 30 %), followed by Epistemonikos (n = 2, Pr = 19 %). No unique records were found in PubMed Health (Pr = 24 %) DARE (Pr = 21 %), TRIP (Pr = 10 %) or MEDLINE (Pr = 10 %). Searching EMBASE and the Cochrane library identified 88 % of all systematic reviews in the reference set, and searching the freely available databases (Cochrane, Epistemonikos, MEDLINE) identified 83 % of all the reviews. The databases were re-analysed after systematic reviews of non-conventional interventions (e.g. yoga, acupuncture) were removed. Similarly, no database identified all the retrieved systematic reviews. EMBASE identified the most relevant systematic reviews (sensitivity 73 %) but also retrieved the most irrelevant citations with Pr = 5 %. The sensitivity of the Cochrane database was 62 %, followed by MEDLINE (60 %), DARE (55 %), PubMed Health (54 %), Epistemonikos (50 %) and TRIP (31 %). The precision of the Cochrane library was the highest (20 %), followed by PubMed Health (Pr = 16 %), DARE (Pr = 13 %), Epistemonikos (Pr = 12 %), MEDLINE (Pr = 6 %), TRIP (Pr = 6 %) and EMBASE (Pr = 5 %). EMBASE contained the most unique records (n = 34). The Cochrane library identified seven unique records. The other databases held no unique records. CONCLUSIONS: The coverage of bibliographic databases varies considerably due to differences in their scope and content. Researchers wishing to identify systematic reviews should not rely on one database but search multiple databases

Parrot Interpreter: Representation, Extinction and the Electronic Information Environment

Humans, it seems, can’t get enough of parrots. Ethnography, folklore, psychology, and, of course, imaginative literature all offer copious evidence of our fantasy of living with, communicating with and even being parrots. The natural history of parrots and the cultural history of parrots present something of a conundrum: on the one hand, a massive destructiveness (illegal bird and feather trade, environment destruction, scientific collections); on the other, an often erotically inflected sympathetic identification leading to the production of new forms. It’s strange to realise that Europe is infested with a shadow population of captive and inbred budgerigars, whose numbers far exceed those remaining in the wild and who can never return to their origins. If, as our privileged other, our uncanny mimic and double, the parrot still fails to survive, what does this tell us about our economy of desire? It seems that to know is to consume and destroy; and that the apparent contrast between the operations of the rainforest loggers and bird-trappers and the sentimental representations and transformations parrot suffers in human society is overdrawn. How is this contradiction to be explained

A stabilizing effect of advection on planar interfaces in singularly perturbed reaction-diffusion equations

We consider planar traveling fronts between stable steady states in two-component singularly perturbed reaction-diffusion-advection equations, where a small quantity $\delta^2$ represents the ratio of diffusion coefficients. The fronts under consideration are large amplitude and contain a sharp interface, induced by traversing a fast heteroclinic orbit in a suitable slow fast framework. We explore the effect of advection on the spectral stability of the fronts to long wavelength perturbations in two spatial dimensions. We find that for suitably large advection coefficient $\nu$, the fronts are stable to such perturbations, while they can be unstable for smaller values of $\nu$. In this case, a critical asymptotic scaling $\nu\sim \delta^{-4/3}$ is obtained at which the onset of instability occurs. The results are applied to a family of traveling fronts in a dryland ecosystem model

Edge FM 87.9 MHz.

Edge FM was developed in partnership with the Museum of Scottish Lighthouses, Fraserburgh, On the Edge Research and the artist, Paul Carter. The research challenge offered up by the project partners was to find a way of drawing young people living locally into the museum. The museum on the outskirts of the town is a lighthouse at Kinnaird Head, known internationally for having an outstanding collection of lenses and of marking the site of a number of technological innovations- the modern lighthouse and the development of radio. The museum's connection and role within this small fishing town seemed of marginal interest to the younger generation. The audio recording of the broadcast on the accompanying CD-ROM has not been added to this OpenAIR record due to being unable to source permissions from the individuals involved

Special symmetries of the charged Kerr-AdS black hole of D=5 minimal gauged supergravity

In this note we prove that the Hamilton-Jacobi equation in the background of the recently discovered charged Kerr-AdS black hole of D=5 minimal gauged supergravity is separable, for arbitrary values of the two rotation parameters. This allows us to write down an irreducible Killing tensor for the spacetime. As a result we also show that the Klein-Gordon equation in this background is separable. We also consider the Dirac equation in this background in the special case of equal rotation parameters and show it has separable solutions. Finally we discuss the near-horizon geometry of the supersymmetric limit of the black hole.Comment: 7 pages, Latex. v2, two references added and discussion of near horizon limit corrected and expande