Strong mutation testing strategies

Mutation Testing (or Mutation Analysis) is a source code testing technique which analyses code by altering code components. The output from the altered code is compared with output from the original code. If they are identical then Mutation Testing has been successful in discerning a weakness in either the test code or the test data. A mutation test therefore helps the tester to develop a program devoid of simple faults with a well developed test data set. The confidence in both program and data set is then increased. Mutation Analysis is resource intensive. It requires program copies, with one altered component, to be created and executed. Consequently, it has been used mainly by academics analysing small programs. This thesis describes an experiment to apply Mutation Analysis to larger, multi-function test programs. Mutations, alterations to the code, are induced using a sequence derived from the code control flow graph. The detection rate of live mutants, programs whose output match the original, was plotted and compared against data generated from the standard technique of mutating in statement order. This experiment was repeated for different code components such as relational operators, conditional statement or pointer references. A test was considered efficient if the majority of live mutants was detected early in the test sequence. The investigations demonstrated that control flow driven mutation could improve the efficiency of a test. However, the experiments also indicated that concentrations of live mutants of a few functions or statements could effect the efficiency of a test. This conclusion lead to the proposal that mutation testing should be directed towards functions or statements containing groupings of the code component that give rise to the live mutants. This effectively forms a test focused onto particular functions or statements

Ammonia in a time of COVID-19. A submission of evidence to Defra/AQEG

A submission to the Air Quality Expert Group (AQEG), an expert committee of the Department for Environment, Food and Rural Affairs (Defra) • Ammonia gas (NH3) is a priority pollutant both as a precursor to particulate matter and for ecosystem impacts. • Three scenarios for UK emission reductions during COVID-19 in emission sectors, where activity is likely reduced ,have been assessed. • Total UK emissions of NH3 are likely to have decreased slightly (~2%), which is within the uncertainty and meteorological variability of the UK atmosphere. • Urban background and urban on road and roadside emissions of NH3 are likely to have decreased, by as much as 30% and 90% respectively compared with usual emissions before COVID-19. • Unratified data from three of the five UK automatic NH3 analysers (Auchencorth Moss, Chilbolton Observatory, and Manchester OSCA Observatory) show typical springtime NH3 concentrations across the UK. • Data from the non-automatic National Ammonia Monitoring Network will enable analysis at UK level in the months ahead. This includes roadside data from London Cromwell Rd. • Evidence gaps & future approaches are outlined. Future analysis of the Defra UKEAP rural networks proposed. • The key measurement gap is urban roadside NH3 (and PM ammonium) as there is only one long-term site in the UK measuring roadside NH3 concentrations. It is suggested that a roadside network of samplers and/or analysers are urgently put in place (perhaps aligned with the UK Urban NO2 Network; UUNN) to monitor NH3 at roadsides during and post COVID-19 lock down where possible

A controlled study to determine the efficacy of Loxostylis alata (Anacardiaceae) in the treatment of aspergillus in a chicken (Gallus domesticus) model in comparison to ketoconazole

BACKGROUND: The poultry industry due to intensive methods of farming is burdened with losses from numerous infectious agents, of which one is the fungus Aspergillus fumigatus. In a preliminary study, the extracts of Loxostylis alata A. Spreng, ex Rchb. showed good activity in vitro against A. fumigatus with a minimum inhibitory concentration of 0.07 mg/ml. For this study crude, a crude acetone extract of L. alata leaves was evaluated for its acute toxicity in a healthy chicken model and for efficacy in an infectious model of aspergillosis (A. fumigatus). RESULTS: At a dose of 300 mg/kg, the extract induced some toxicity characterised by decreased feed intake and weight loss. Consequently, 100 and 200 mg/kg were used to ascertain efficacy in the infectious model. The plant extract significantly reduced clinical disease in comparison to the control in a dose dependant manner. The extract was as effective as the positive control ketoconazole dosed at 60 mg/kg. CONCLUSIONS: The results indicate that a crude extract of L. alata leaves has potential as an antifungal agent to protect poultry against avian aspergillosis.The South African National Research Foundation and the Research Committee of the Faculty of Veterinary Science, University of Pretoriahttp://www.biomedcentral.com/1746-6148/8/210am2013mn201

A radium assay technique using hydrous titanium oxide adsorbent for the Sudbury Neutrino Observatory

As photodisintegration of deuterons mimics the disintegration of deuterons by neutrinos, the accurate measurement of the radioactivity from thorium and uranium decay chains in the heavy water in the Sudbury Neutrino Observatory (SNO) is essential for the determination of the total solar neutrino flux. A radium assay technique of the required sensitivity is described that uses hydrous titanium oxide adsorbent on a filtration membrane together with a beta-alpha delayed coincidence counting system. For a 200 tonne assay the detection limit for 232Th is a concentration of 3 x 10^(-16) g Th/g water and for 238U of 3 x 10^(-16) g U/g water. Results of assays of both the heavy and light water carried out during the first two years of data collection of SNO are presented.Comment: 12 pages, 4 figure

Precision Pion-Proton Elastic Differential Cross Sections at Energies Spanning the Delta Resonance

A precision measurement of absolute pi+p and pi-p elastic differential cross sections at incident pion laboratory kinetic energies from T_pi= 141.15 to 267.3 MeV is described. Data were obtained detecting the scattered pion and recoil proton in coincidence at 12 laboratory pion angles from 55 to 155 degrees for pi+p, and six angles from 60 to 155 degrees for pi-p. Single arm measurements were also obtained for pi+p energies up to 218.1 MeV, with the scattered pi+ detected at six angles from 20 to 70 degrees. A flat-walled, super-cooled liquid hydrogen target as well as solid CH2 targets were used. The data are characterized by small uncertainties, ~1-2% statistical and ~1-1.5% normalization. The reliability of the cross section results was ensured by carrying out the measurements under a variety of experimental conditions to identify and quantify the sources of instrumental uncertainty. Our lowest and highest energy data are consistent with overlapping results from TRIUMF and LAMPF. In general, the Virginia Polytechnic Institute SM95 partial wave analysis solution describes our data well, but the older Karlsruhe-Helsinki PWA solution KH80 does not.Comment: 39 pages, 22 figures (some with quality reduced to satisfy ArXiv requirements. Contact M.M. Pavan for originals). Submitted to Physical Review

Strategies to augment non-immune system based defence mechanisms against gastrointestinal diseases in pigs

AbstractOur study addresses the first two weeks of the weaning period of piglets during which stressful physiological and environmental conditions experienced by the animals can promote the proliferation of pathogens in the digestive tract. The aim of the study was to identify new feeding strategies that result in boosting the gastrointestinal tract (GIT) microbiota of piglets and improve growth performance, reducing the negative impact of weaning. In order to identify a new synbiotic combination, 12 new putative probiotic strains of Bifidobacterium spp. and three non-digestible oligosaccharides [NDO] were screened in newly weaned piglets. The ability to increase the level of autochthonous bifidobacteria and improve growth performance were assessed. Bifidobacteria strains with a similar ability to develop in the hindgut showed a different effect on piglet performance depending on the dose in which they were provided. Our data support the idea that the presence of fructo-oligosaccharides would stimulate the occurrence of bifidobacteria in the caecum. It was shown that dietary intake of nitrate can generate salivary nitrite, which in turn is acidified in the stomach and could have antimicrobial activity against swallowed pathogens. The efficacy of the resulting synbiotic formula was improved by adding nitrate as antimicrobial. To enhance probiotic survival during gastric transit, a novel technology of microencapsulation was developed and applied to bacteria. The final synbiotic, containing the strain RA 18 of Bifidobacterium animalis subsp. lactis [1011cfu/day], the prebiotic Actilight® [4% of the diet], and nitrate [150mg KNO3/kg feed/day] was tested in organic weaned piglets reared under field conditions. Results show that the strain Ra 18 had a probiotic effect in organic weaned piglets, as it colonized and remained detectable in faecal samples until two weeks after addition. The use of our synbiotic formula improved weight gain, feed efficiency and health status of the weaned piglets

Origin and Evolution of Saturn's Ring System

The origin and long-term evolution of Saturn's rings is still an unsolved problem in modern planetary science. In this chapter we review the current state of our knowledge on this long-standing question for the main rings (A, Cassini Division, B, C), the F Ring, and the diffuse rings (E and G). During the Voyager era, models of evolutionary processes affecting the rings on long time scales (erosion, viscous spreading, accretion, ballistic transport, etc.) had suggested that Saturn's rings are not older than 100 My. In addition, Saturn's large system of diffuse rings has been thought to be the result of material loss from one or more of Saturn's satellites. In the Cassini era, high spatial and spectral resolution data have allowed progress to be made on some of these questions. Discoveries such as the ''propellers'' in the A ring, the shape of ring-embedded moonlets, the clumps in the F Ring, and Enceladus' plume provide new constraints on evolutionary processes in Saturn's rings. At the same time, advances in numerical simulations over the last 20 years have opened the way to realistic models of the rings's fine scale structure, and progress in our understanding of the formation of the Solar System provides a better-defined historical context in which to understand ring formation. All these elements have important implications for the origin and long-term evolution of Saturn's rings. They strengthen the idea that Saturn's rings are very dynamical and rapidly evolving, while new arguments suggest that the rings could be older than previously believed, provided that they are regularly renewed. Key evolutionary processes, timescales and possible scenarios for the rings's origin are reviewed in the light of tComment: Chapter 17 of the book ''Saturn After Cassini-Huygens'' Saturn from Cassini-Huygens, Dougherty, M.K.; Esposito, L.W.; Krimigis, S.M. (Ed.) (2009) 537-57

Health promotion: results of focus groups with African-American men

http://dx.doi.org/10.1016/j.jomh.2010.11.00

Dynamics of spherically symmetric spacetimes: hydrodynamics and radiation

Using the 3+1 formalism of general relativity we obtain the equations governing the dynamics of spherically symmetric spacetimes with arbitrary sources. We then specialize for the case of perfect fluids accompanied by a flow of interacting massless or massive particles (e.g. neutrinos) which are described in terms of relativistic transport theory. We focus in three types of coordinates: 1) isotropic gauge and maximal slicing, 2) radial gauge and polar slicing, and 3) isotropic gauge and polar slicing.Comment: submitted to Phys. Rev. D, 46 pages, RevTex file, no figure