22,666 research outputs found
Weak lensing with COMBO-17: estimation and removal of intrinsic alignments
We estimate and remove the contamination of weak gravitational lensing
measurements by the intrinsic alignment of close pairs of galaxies. We do this
by investigating both the aperture mass B mode statistic, and the shear
correlations of close and distant pairs of galaxies. We re-analyse the COMBO-17
survey, and study published results from the RCS and the VIRMOS-DESCART survey,
concluding that the intrinsic alignment effect is at the lower end of the range
of theoretical predictions. We also revisit this theoretical issue, and show
that misalignment of baryon and halo angular momenta may be an important effect
which can reduce the intrinsic ellipticity correlations estimated from
numerical simulations to the level that we and the SuperCOSMOS survey observe.
We re-examine the cosmological parameter estimation from the COMBO-17 survey,
now marginalising over the Hubble constant. Assuming no evolution in galaxy
clustering, and marginalising over the intrinsic alignment signal, we find the
mass clustering amplitude is reduced by 0.03 to sigma_8(Omega_m / 0.27)^0.6 =
0.71 +/- 0.11. We consider the forthcoming SNAP wide weak lensing survey, and
the CFHTLS wide synoptic survey, and expect them to be contaminated on scales
>1 arcmin by intrinsic alignments at the level of ~1% and ~2% respectively.
Division of the SNAP survey for lensing tomography significantly increases the
contamination in the lowest redshift bin to ~7% and possibly higher. Removal of
the intrinsic alignment effect by the downweighting of nearby galaxy pairs will
therefore be vital for SNAP, (abridged).Comment: Accepted for publication in MNRAS, 15 pages, 18 figure
Using design-based research to improve the lesson study approach to professional development in Camden (London)
The Haverstock Primary to Secondary Transition Project was designed to improve the experience of transition to secondary school for vulnerable pupils in Camden (London). The project used lesson study to help primary and secondary practitioners work collaboratively, to develop effective cross-phase pedagogical approaches to teaching English/literacy and science. This paper has three specific aims in relation to the project. First it reports on how a design-based research (DBR) method was used to tailor the lesson study approach to the Camden context in order to maximize its benefits and ensure its sustainability and scalability. Second it illustrates how a DBR approach to impact assessment led to a radical rethink and understanding of how impact might be measured with regard to projects that involve joint practice development. Specifically, collaborative approaches to practice development rely on more iterative, evolving approaches to understanding and collecting baseline data, developing strategies, and understanding the goals to be reached. Finally, it provides initial data on the impact of the DBR-led lesson study approach
Patient Satisfaction as a Reflection of Quality Health Care and Outcomes
Background: In 2006 the Centers of Medicaid and Medicare Services mandated that acute care centers begin submitting HCAHPS survey data for financial reimbursement for Medicare patients. The national shift to a patient centered focus and the financial incentive to improve patient satisfaction scores has stimulated debate regarding the relationship between patient satisfaction and quality healthcare.
Clinical Question: Does improvement in patient satisfaction with their healthcare and its providers, as measured by the HCAHPS survey, improve healthcare quality and outcomes?
Design: Systematic literature review.
Methods: Searches were performed using PubMed and Scopus databases.The terms used for the PubMed search were âpatient satisfactionâ and âHCAHPSâ with filters for full text, last 10 years and English. The terms for the Scopus search were âqualityâ, âpatient satisfactionâ and âcareâ with filters for English, from 2010 and âLimit Exact Keyword âpatient satisfactionâ.â
Results: The PubMed search found two articles: Jha et al., and Kennedy et. al. Another study was located in PubMed using âfrequently viewed togetherâ hyperlink: Fenton, et al. The Scopus database search located an additional two articles: Lyu et a.l, and Tsai et al.
Conclusions: The relationship between patient satisfaction and healthcare quality remains elusive. Within this review, two articles showed a positive association, one showed a negative association and two that supported the null hypothesis. Limitations to the HCAHPS survey and various quality assessment tools prevent the adequate assessment regarding the association between patient satisfaction and healthcare quality. Further refinement of the HCAHPS and quality assessment tools are required to help determine a more concrete relationship
Platensimycin Activity against Mycobacterial ÎČ-Ketoacyl-ACP Synthases
Background - There is an urgent need for the discovery and development of new drugs against Mycobacterium tuberculosis, the causative agent of tuberculosis, especially due to the recent emergence of multi-drug and extensively-drug resistant strains. Herein, we have examined the susceptibility of mycobacteria to the natural product platensimycin.
Methods and Findings - We have demonstrated that platensimycin has bacteriostatic activity against the fast growing Mycobacterium smegmatis (MIC = 14 ”g/ml) and against Mycobacterium tuberculosis (MIC = 12 ”g/ml). Growth in the presence of paltensimycin specifically inhibited the biosynthesis of mycolic acids suggesting that the antibiotic targeted the components of the mycolate biosynthesis complex. Given the inhibitory activity of platensimycin against ÎČ-ketoacyl-ACP synthases from Staphylococcus aureus, M. tuberculosis KasA, KasB or FabH were overexpressed in M. smegmatis to establish whether these mycobacterial KAS enzymes were targets of platensimycin. In M. smegmatis overexpression of kasA or kasB increased the MIC of the strains from 14 ”g/ml, to 30 and 124 ”g/ml respectively. However, overexpression of fabH on did not affect the MIC. Additionally, consistent with the overexpression data, in vitro assays using purified proteins demonstrated that platensimycin inhibited Mt-KasA and Mt-KasB, but not Mt-FabH.
Significance - Our results have shown that platensimycin is active against mycobacterial KasA and KasB and is thus an exciting lead compound against M. tuberculosis and the development of new synthetic analogues
Perspectives on teacher leadership for evidence-informed improvement in England
With a national policy emphasis in England on evidence-based teaching within a self-improving school system, teachers need to create and use knowledge to best effect. It is also imperative that they collaborate within and across schools to develop and deepen their practice. In this context, middle and other teacher leaders can play an important role in enhancing improvement. In this article we will first set out the national context for teacher leadership and improvement, signposting key shifts over the last 10 years. We will then describe three national projects and some key findings: a middle leader knowledge exchange project with Challenge Partners, a national network of schools, funded by the Economic and Social Research Council (ESRC); Research Learning Communities, a research use randomized control trial project, in its first of two years, funded by the Educational Endowment Foundation; and a National College for Teaching and Leadership funded network enquiry project. Finally, we will discuss issues and challenges and implications for teacher leadership of improvement
Sediment Management for Southern California Mountians, Coastal Plains and Shoreline. Part D: Special Inland Studies
In southern California the natural environmental system involves the continual relocation of sedimentary materials. Particles are eroded from inland areas where there is sufficient relief and, precipitation. Then, with reductions in hydraulic gradient along the stream course and at the shoreline, the velocity of surface runoff is reduced and there is deposition. Generally, coarse sand, gravel and larger particles are deposited near the base of the eroding surfaces (mountains and hills) and the finer sediments are deposited on floodplains, in bays or lagoons, and at the shoreline as delta deposits. Very fine silt and clay particles, which make up a significant part of the eroded material, are carried offshore where they eventually deposit in deeper areas. Sand deposited at the shoreline is gradually moved along the coast by waves and currents, and provides nourishment for local beaches. However, eventually much of this littoral material is also lost to offshore areas. Human developments in the coastal region have substantially altered the natural sedimentary processes, through changes in land use, the harvesting of natural resources (logging, grazing, and sand and gravel mining); the construction and operation of water conservation facilities and flood control structures; and coastal developments. In almost all cases these developments have grown out of recognized needs and have well served their primary purpose. At the time possible deleterious effects on the local or regional sediment balance were generally unforeseen or were felt to be of secondary importance. In 1975 a large-scale study of inland and coastal sedimentation processes in southern California was initiated by the Environmental Quality Laboratory at the California Institute of Technology and the Center for Coastal Studies at Scripps Institution of Oceanography. This volume is one of a series of reports from this study. Using existing data bases, this series attempts to define quantitatively inland and coastal sedimentation processes and identify the effects man has had on these processes. To resolve some issues related to long-term sediment management, additional research and data will be needed. In the series there are four Caltech reports that provide supporting studies for the summary report (EQL Report No. 17). These reports include: EQL Report 17-A Regional Geological History EQL Report 17-B Inland Sediment Movements by Natural Processes EQL Report 17-C Coastal Sediment Delivery by Major Rivers in Southern California EQL Report 17-D -- Special Inland Studies Additional supporting reports on coastal studies (shoreline sedimentation processes, control structures, dredging, etc.) are being published by the Center for Coastal Studies at Scripps Institution of Oceanography, La Jolla, California
Financial expectations and household consumption : does middle inflation matter?
Using British panel data, we explore the Finding that households often expect their financial position to remain unchanged compared to other alternatives, using a generalised middle inflated ordered probit (GMIOP) model. In doing so we account for the tendency of individuals to choose âneutralâ responses when faced with attitudinal and opinion-based questions, which are a common feature of survey data. Our empirical analysis strongly supports the use of a GMIOP model to account for this response pattern. Expectations indices based on competing discrete choice models are then exploited to explore the role that financial expectations play in driving the consumption of different types of durable goods and the amount of expenditure undertaken. Whilst financial optimism is significantly associated with consumption, indices which fail to take into account middle-inflation are found to overestimate the impact of financial expectations
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