2,542 research outputs found
Measuring Coverage of Prolog Programs Using Mutation Testing
Testing is an important aspect in professional software development, both to
avoid and identify bugs as well as to increase maintainability. However,
increasing the number of tests beyond a reasonable amount hinders development
progress. To decide on the completeness of a test suite, many approaches to
assert test coverage have been suggested. Yet, frameworks for logic programs
remain scarce.
In this paper, we introduce a framework for Prolog programs measuring test
coverage using mutations. We elaborate the main ideas of mutation testing and
transfer them to logic programs. To do so, we discuss the usefulness of
different mutations in the context of Prolog and empirically evaluate them in a
new mutation testing framework on different examples.Comment: 16 pages, Accepted for presentation in WFLP 201
Proof Relevant Corecursive Resolution
Resolution lies at the foundation of both logic programming and type class
context reduction in functional languages. Terminating derivations by
resolution have well-defined inductive meaning, whereas some non-terminating
derivations can be understood coinductively. Cycle detection is a popular
method to capture a small subset of such derivations. We show that in fact
cycle detection is a restricted form of coinductive proof, in which the atomic
formula forming the cycle plays the role of coinductive hypothesis.
This paper introduces a heuristic method for obtaining richer coinductive
hypotheses in the form of Horn formulas. Our approach subsumes cycle detection
and gives coinductive meaning to a larger class of derivations. For this
purpose we extend resolution with Horn formula resolvents and corecursive
evidence generation. We illustrate our method on non-terminating type class
resolution problems.Comment: 23 pages, with appendices in FLOPS 201
Opportunities for topical antimicrobial therapy: permeation of canine skin by fusidic acid
BACKGROUND: Staphylococcal infection of the canine epidermis and hair follicle is amongst the commonest reasons for antimicrobial prescribing in small animal veterinary practice. Topical therapy with fusidic acid (FA) is an attractive alternative to systemic therapy based on low minimum inhibitory concentrations (MICs, commonly <0.03 mg/l) documented in canine pathogenic staphylococci, including strains of MRSA and MRSP (methicillin-resistant Staphylococcus aureus and S. pseudintermedius). However, permeation of canine skin by FA has not been evaluated in detail. This study aimed to define the degree and extent of FA permeation in canine skin in vitro from two sites with different hair follicle density following application of a licensed ophthalmic formulation that shares the same vehicle as an FA-betamethasone combination product approved for dermal application in dogs. Topical FA application was modelled using skin held in Franz-type diffusion cells. Concentrations of FA in surface swabs, receptor fluid, and transverse skin sections of defined anatomical depth were determined using high-performance liquid chromatography and ultraviolet (HPLC-UV) analysis. RESULTS: The majority of FA was recovered by surface swabs after 24 h, as expected (mean ± SEM: 76.0 ± 17.0%). FA was detected within 424/470 (90%) groups of serial sections of transversely cryotomed skin containing follicular infundibula, but never in 48/48 (100%) groups of sections containing only deeper follicular structures, nor in receptor fluid, suggesting that FA does not permeate beyond the infundibulum. The FA concentration (mean ± SEM) in the most superficial 240 μm of skin was 2000 ± 815 μg/g. CONCLUSIONS: Topically applied FA can greatly exceed MICs for canine pathogenic staphylococci at the most common sites of infection. Topical FA therapy should now be evaluated using available formulations in vivo as an alternative to systemic therapy for canine superficial bacterial folliculitis.Peer reviewedFinal Published versio
Nanomedicine - nanoparticles, molecular biosensors and targeted gene/drug delivery for combined single-cell diagnostics and therapeutics
Next generation nanomedicine technologies are being developed to provide for continuous and linked molecular diagnostics and therapeutics. Research is being performed to develop "sentinel nanoparticles" which will seek out diseased (e.g. cancerous) cells, enter those living cells, and either perform repairs or induce those cells to die through apoptosis. These nanoparticles are envisioned as multifunctional "smart drug delivery systems"
Quantum enhanced positioning and clock synchronization
A wide variety of positioning and ranging procedures are based on repeatedly
sending electromagnetic pulses through space and measuring their time of
arrival. This paper shows that quantum entanglement and squeezing can be
employed to overcome the classical power/bandwidth limits on these procedures,
enhancing their accuracy. Frequency entangled pulses could be used to construct
quantum positioning systems (QPS), to perform clock synchronization, or to do
ranging (quantum radar): all of these techniques exhibit a similar enhancement
compared with analogous protocols that use classical light. Quantum
entanglement and squeezing have been exploited in the context of
interferometry, frequency measurements, lithography, and algorithms. Here, the
problem of positioning a party (say Alice) with respect to a fixed array of
reference points will be analyzed.Comment: 4 pages, 2 figures. Accepted for publication by Natur
Detailed statistical analysis plan for a cluster randomised controlled trial of the Healthy Lifestyles Programme (HeLP), a novel school-based intervention to prevent obesity in school children
This is the final version of the article. Available from the publisher via the DOI in this record.BACKGROUND: The Healthy Lifestyles Programme (HeLP) trial is being conducted to determine whether a novel school-based intervention is effective and cost-effective in preventing obesity in 9-10 year-old children. This article describes the detailed statistical analysis plan for the HeLP trial, including an amendment (and rationale for amendment) made to originally planned sensitivity analyses. METHODS AND DESIGN: The HeLP trial is a definitive, pragmatic, superiority, cluster randomised controlled trial with two parallel groups and blinded outcome assessment. This update article describes in detail (1) the primary and secondary outcomes, (2) the statistical analysis principles (including which children will be included in each analysis, how the clustered nature of the study design will be accounted for, which covariates will be included in each analysis, how the results will be presented), (3) planned sensitivity analyses, planned subgroup analyses and planned adherence-adjusted analyses for the primary outcome, (4) planned analyses for the secondary outcomes and (e) planned longitudinal analyses. TRIAL REGISTRATION: International Standard Randomised Controlled Trial Number (ISRCTN) register: ISRCTN15811706 . Registered on 1 May 2012.The definitive trial of HeLP is funded by the UK National Institute for Health
Research (NIHR) Public Health Research Programme (10/3010/01) and a full
report will be published on the NIHR website. KW and JL are partially
supported by PenCLAHRC, the National Institute for Health Research (NIHR)
CLAHRC for the Southwest Peninsul
Optical codeword demodulation with error rates below standard quantum limit using a conditional nulling receiver
The quantum states of two laser pulses---coherent states---are never mutually
orthogonal, making perfect discrimination impossible. Even so, coherent states
can achieve the ultimate quantum limit for capacity of a classical channel, the
Holevo capacity. Attaining this requires the receiver to make joint-detection
measurements on long codeword blocks, optical implementations of which remain
unknown. We report the first experimental demonstration of a joint-detection
receiver, demodulating quaternary pulse-position-modulation (PPM) codewords at
a word error rate of up to 40% (2.2 dB) below that attained with
direct-detection, the largest error-rate improvement over the standard quantum
limit reported to date. This is accomplished with a conditional nulling
receiver, which uses optimized-amplitude coherent pulse nulling, single photon
detection and quantum feedforward. We further show how this translates into
coding complexity improvements for practical PPM systems, such as in deep-space
communication. We anticipate our experiment to motivate future work towards
building Holevo-capacity-achieving joint-detection receivers.Comment: 6 pages, 4 figure
Seasonal Changes in Physical Qualities of Elite Youth Soccer Players according to Maturity Status: Comparisons with Aged Matched Controls.
Purpose: Longitudinal studies assessing the seasonal development of strength, speed and power qualities are limited in youth soccer players. The purpose of this study was to evaluate the seasonal changes in the physical development of elite youth soccer players across Pre-, Circa- and Post-Peak Height Velocity (PHV), against a similar age and maturity matched control groups. Methods: One-hundred and twelve male elite youth soccer players (Pre-PHV n = 55; Circa-PHV n = 21; Post-PHV n = 36) and 38 controls consisting of non-elite active participants (Pre-PHV n = 18; Circa-PHV n = 10; Post-PHV n = 10) all undertook isometric mid-thigh pull strength, 10–30 m sprints, change of direction speed (CODs) and countermovement jump (CMJ) tests pre- and post-season. Results: The elite Circa-PHV improved greater than the control group for all physical qualities between pre- and post-season. The elite Pre-PHV improved greater in sprints, CODs, CMJ jump height and strength while the elite Post-PHV group improved more in CODs and strength than their respective control groups. Conclusion: Findings suggest that systematic academy soccer training enhances the development of physical qualities in youth soccer players but maturity status may impact upon such adaptations
The deglacial history of 79N glacier and the Northeast Greenland Ice Stream
\ua9 2024 The AuthorsThe Northeast Greenland Ice Stream (NEGIS) is the main artery for ice discharge from the northeast sector of the Greenland Ice Sheet (GrIS) to the North Atlantic. Understanding the past, present and future stability of the NEGIS with respect to atmospheric and oceanic forcing is of global importance as it drains around 17% of the GrIS and has a sea-level equivalent of 1.6 m. This paper reconstructs the deglacial and Holocene history of Nioghalvfjerdsbr\ue6 (or 79N Glacier); a major outlet of the NEGIS. At high elevation (>900 m asl) autochthonous blockfield, a lack of glacially moulded bedrock and pre LGM exposure ages point to a complex exposure/burial history extending back over half a million years. However, post Marine Isotope Stage 12, enhanced glacial erosion led to fjord incision and plateaux abandonment. Between 900 and 600 m asl the terrain is largely unmodified by glacial scour but post LGM erratics indicate the advection of cold-based ice through the fjord. In contrast, below ∼600 m asl Nioghalvfjerdsfjorden exhibits a geomorphological signal indicative of a warm-based ice stream operating during the last glacial cycle. Dated ice marginal landforms and terrain along the fjord walls show initial thinning rates were slow between ∼23 and 10 ka, but post-10 ka it is evident that Nioghalvfjerdsfjorden deglaciated extremely quickly with complete fjord deglaciation below ∼500 m asl between 10.0 and 8.5 ka. Both increasing air and ocean temperatures were pivotal in driving surface lowering and submarine melt during deglaciation, but the final withdrawal of ice through Nioghalvfjerdsfjorden was facilitated by the action of marine ice sheet instability. Our estimates show that thinning and retreat rates reached a maximum of 5.29 ma−1 and 613 ma−1, respectively, as the ice margin withdrew westwards. This would place the Early Holocene disintegration of this outlet of the NEGIS at the upper bounds of contemporary thinning and retreat rates seen both in Greenland and Antarctica. Combined with recent evidence of ice stream shutdown during the Holocene, as well as predictions of changing ice flow dynamics within downstream sections of the NEGIS catchment, this suggests that significant re-organisation of the terminal zone of the ice stream is imminent over the next century
IACT observations of gamma-ray bursts: prospects for the Cherenkov Telescope Array
Gamma rays at rest frame energies as high as 90 GeV have been reported from
gamma-ray bursts (GRBs) by the Fermi Large Area Telescope (LAT). There is
considerable hope that a confirmed GRB detection will be possible with the
upcoming Cherenkov Telescope Array (CTA), which will have a larger effective
area and better low-energy sensitivity than current-generation imaging
atmospheric Cherenkov telescopes (IACTs). To estimate the likelihood of such a
detection, we have developed a phenomenological model for GRB emission between
1 GeV and 1 TeV that is motivated by the high-energy GRB detections of
Fermi-LAT, and allows us to extrapolate the statistics of GRBs seen by lower
energy instruments such as the Swift-BAT and BATSE on the Compton Gamma-ray
Observatory. We show a number of statistics for detected GRBs, and describe how
the detectability of GRBs with CTA could vary based on a number of parameters,
such as the typical observation delay between the burst onset and the start of
ground observations. We also consider the possibility of using GBM on Fermi as
a finder of GRBs for rapid ground follow-up. While the uncertainty of GBM
localization is problematic, the small field-of-view for IACTs can potentially
be overcome by scanning over the GBM error region. Overall, our results
indicate that CTA should be able to detect one GRB every 20 to 30 months with
our baseline instrument model, assuming consistently rapid pursuit of GRB
alerts, and provided that spectral breaks below 100 GeV are not a common
feature of the bright GRB population. With a more optimistic instrument model,
the detection rate can be as high as 1 to 2 GRBs per year.Comment: 28 pages, 24 figures, 4 tables, submitted to Experimental Astronom
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