8,469 research outputs found
Including Systematic Uncertainties in Confidence Interval Construction for Poisson Statistics
One way to incorporate systematic uncertainties into the calculation of
confidence intervals is by integrating over probability density functions
parametrizing the uncertainties. In this note we present a development of this
method which takes into account uncertainties in the prediction of background
processes, uncertainties in the signal detection efficiency and background
efficiency and allows for a correlation between the signal and background
detection efficiencies. We implement this method with the Feldman & Cousins
unified approach with and without conditioning. We present studies of coverage
for the Feldman & Cousins and Neyman ordering schemes. In particular, we
present two different types of coverage tests for the case where systematic
uncertainties are included. To illustrate the method we show the relative
effect of including systematic uncertainties the case of dark matter search as
performed by modern neutrino tel escopes.Comment: 23 pages, 10 figures, replaced to match published versio
Feedback from activity trackers improves daily step count after knee and hip arthroplasty: A randomized controlled trial
Background: Commercial wrist-worn activity monitors have the potential to accurately assess activity levels and are being increasingly adopted in the general population. The aim of this study was to determine if feedback from a commercial activity monitor improves activity levels over the first 6 weeks after total hip arthroplasty (THA) or total knee arthroplasty (TKA).
Methods: One hundred sixty-three consecutive subjects undergoing primary TKA or THAwere randomized into 2 groups. Subjects received an activity tracker with the step display obscured 2 weeks before surgery and completed patient-reported outcome measures (PROMs). On day 1 after surgery, participants were randomized to either the “feedback (FB) group” or the “no feedback (NFB) group.” The FB group was able to view their daily step count and was given a daily step goal. Participants in the NFB group wore the device with the display obscured for 2 weeks after surgery, after which time they were also able to see their daily step count but did not receive a formal step goal. The mean daily steps at 1, 2, 6 weeks, and 6 months were monitored. At 6 months after surgery, subjects repeated PROMs and daily step count collection.
Results: Of the 163 subjects, 95 underwent THA and 68 underwent TKA. FB subjects had a significantly higher (P \u3c .03) mean daily step count by 43% in week 1, 33% in week 2, 21% in week 6, and 17% at 6 months, compared with NFB. The FB subjects were 1.7 times more likely to achieve a mean 7000 steps per day than the NFB subjects at 6 weeks after surgery (P ÂĽ .02). There was no significant difference between the groups in PROMs at 6 months. Ninety percent of FB and 83% of NFB participants reported that they were satisfied with the results of the surgery (P ÂĽ .08). At 6 months after surgery, 70% of subjects had a greater mean daily step count compared with their preoperative level.
Conclusion: Subjects who received feedback from a commercial activity tracker with a daily step goal had significantly higher activity levels after hip and knee arthroplasty over 6 weeks and 6 months, compared with subjects who did not receive feedback in a randomized controlled trial. Commercial activity trackers may be a useful and effective adjunct after arthroplasty
pi-Conjugation and conformation in a semiconducting polymer: small angle x-ray scattering study
Small angle X-ray scattering (SAXS) in
poly[2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) solution
has shown the important role of pi-electron conjugation in controlling the
chain conformation and assembly. By increasing the extent of conjugation from
30 to 100 %, the persistence length (l_p) increases from 20 to 66 Angstrom.
Moreover, a pronounced second peak in the pair distribution function has been
observed in fully conjugated chain, at larger length scales. This feature
indicates that the chain segments tend to self-assemble as the conjugation
along the chain increases. Xylene enhances the rigidity of PPV backbone to
yield extended structures, while tetrahydrofuran solvates the side groups to
form compact coils in which the l_p is much shorter.Comment: accepted (J. Phy. Cond. Mat.
Diversity in the structures and ligand binding sites of nematode fatty acid and retinol binding proteins revealed by Na-FAR-1 from Necator americanus
Fatty acid and retinol binding proteins (FARs) comprise a family of unusual α-helix rich lipid binding proteins found exclusively in nematodes. They are secreted into host tissues by parasites of plants, animals and humans. The structure of a FAR protein from the free-living nematode Caenorhabditis elegans is available, but this protein (Ce-FAR-7) is from a subfamily of FARs that does not appear to be important at the host-parasite interface. We have therefore examined Na-FAR-1 from the blood-feeding intestinal parasite of humans, Necator americanus . The three dimensional structure of Na-FAR-1 in its ligand-free and ligand-bound forms, determined by nuclear magnetic resonance spectroscopy (NMR) and X-ray crystallography, respectively, reveals an a-helical fold similar to Ce-FAR-7, but Na-FAR-1 possesses a larger and more complex internal ligand binding cavity and an additional C-terminal a-helix. Titration of apo -Na-FAR-1 with oleic acid, analysed by NMR chemical shift perturbation, reveals that at least four distinct protein:ligand complexes can be formed. Na-FAR-1, and possibly other FARs, may have a wider repertoire for hydrophobic ligand binding, as confirmed here by our finding that a range of neutral and polar lipids co-purify with the bacterial recombinant protein. Finally, we show by immunohistochemistry that Na-FAR-1 is present in adult worms with a tissue distribution indicative of possible roles in nutrient acquisition by the parasite and in reproduction in the male
The American Corporation in the Twenty-first Century
Opportunistic Downsizing of Senior Workers: Exploring the Fiduciary/Contract Distinction to Enforce Implicit Employment Agreements lecture given by Marleen A. O\u27Connor, Professor of Law at Stetson College.
The Motivational Implications of Debt Financing lecture given by George Triantis, Nicholas E. Chimicles Research Professor of Business Law and Regulation at the University of Virginia and the Director of the John M. Olin Program in Law and Economics.
Political Backlash and the Corporation lecture given by Mark Roe, Professor of Law at Columbia University and Director of the Columbia Law School Sloan Project on Corporate Governance.
Venture Capital and the Structure of Capital Markets: Banks versus Stock Markets lecture given by Ronald J. Gilson, Charles J. Meyers Professor of Law and Business at Stanford University and The Marc and Eva Stern Professor of Law and Business at Columbia University.
The Shaping Force of Corporate Law in the New Economic Order lecture given by Jeffrey N. Gordon, Professor of Law and Co-director Center for Law and Economic Studies at Columbia University
Innovation in overcoming road rehabilitation challenges faced in an urban environment: An in-depth case study
Paper presented at the 32nd Annual Southern African Transport Conference 8-11 July 2013 "Transport and Sustainable Infrastructure", CSIR International Convention Centre, Pretoria, South Africa.The design and implementation of a pavement rehabilitation project in a Central Business
District (CBD) of a city poses numerous challenges. These challenges include the high design traffic, depth of pavement rehabilitation, presence of many services, traffic accommodation, pedestrian accommodation, construction period, construction materials,
final level of construction, environmental and social impact and sustainability.
The paper presents a case study of an innovative pavement design and construction process for the rehabilitation of Harvey Road and Hanger Street in Bloemfontein, South Africa. The paper addresses the practical rehabilitation option, which met the challenges faced on the project, as well as the construction materials mix design details, construction
methods, time frames during construction as well as a cost comparison between conventional deep rehabilitation pavements and the innovative rehabilitation pavement.
The design incorporates a bitumen emulsion stabilised crushed stone base, which includes reclaimed asphalt, paved with a paver on top of a mechanical stabilising grid.This paper was transferred from the original CD ROM created for this conference. The material was published using Adobe Acrobat 10.1.0 Technology.
The original CD ROM was produced by Document Transformation Technologies Postal Address: PO Box 560 Irene 0062 South Africa. Tel.: +27 12 667 2074 Fax: +27 12 667 2766 E-mail: nigel@doctech URL: http://www.doctech.co.zamv201
Two crystal forms of a helix-rich fatty acid- and retinol-binding protein, Na-FAR-1, from the parasitic nematode Necator americanus
Na-FAR-1 is an unusual -helix-rich fatty acid- and retinol-binding protein from Necator americanus, a blood-feeding intestinal parasitic nematode of humans. It belongs to the FAR protein family, which is unique to nematodes; no structural information is available to date for FAR proteins from parasites. Crystals were obtained with two different morphologies that corresponded to different space groups. Crystal form 1 exhibited space group P432 (unit-cell parameters a = b = c = 120.80 Ă…, α = β = Îł = 90°) and diffracted to 2.5 Ă… resolution, whereas crystal form 2 exhibited space group F23 (unit-cell parameters a = b = c = 240.38 Ă…, α = β = Îł = 90°) and diffracted to 3.2 Ă… resolution. Crystal form 2 showed signs of significant twinning.Instituto de Investigaciones BioquĂmicas de La Plat
Ethics, space, and somatic sensibilities: comparing relationships between scientific researchers and their human and animal experimental subjects
Drawing on geographies of affect and nature-society relations, we propose a radical rethinking of how scientists, social scientists, and regulatory agencies conceptualise human and animal participants in scientif ic research. The scientific rationale for using animal bodies to simulate what could be done in human bodies emphasises shared somatic capacities that generate comparable responses to clinical interventions. At the same time, regulatory guidelines and care practices stress the differences between human and animal subjects. In this paper we consider the implications of this differentiation between human and animal bodies in ethical and welfare protocols and practices. We show how the bioethical debates around the use of human subjects tend to focus on issues of consent and language, while recent work in animal welfare reflects an increasing focus on the affectual dimensions of ethical practice. We argue that this attention to the more-than-representational dimensions of ethics and welfare might be equally important for human subjects. We assert that paying attention to these somatic sensibilities can offer insights into how experimental environments can both facilitate and restrict the development of more care-full and response-able relations between researchers and their experimental subjects. <br/
Spectral Bounds for Dirac Operators on Open Manifolds
We extend several classical eigenvalue estimates for Dirac operators on
compact manifolds to noncompact, even incomplete manifolds. This includes
Friedrich's estimate for manifolds with positive scalar curvature as well as
the author's estimate on surfaces.Comment: pdflatex, 14 pages, 3 figure
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