230 research outputs found
Feasibility study of an Integrated Program for Aerospace-vehicle Design (IPAD) system. Volume 2: Characterization of the IPAD system, phase 1, task 1
The aircraft design process is discussed along with the degree of participation of the various engineering disciplines considered in this feasibility study
Covrig: a framework for the analysis of code, test, and coverage evolution in real software
Copyright 2014 ACM.Software repositories provide rich information about the construction and evolution of software systems. While static data that can be mined directly from version control systems has been extensively studied, dynamic metrics concerning the execution of the software have received much less attention, due to the inherent difficulty of running and monitoring a large number of software versions. In this paper, we present Covrig, a flexible infrastructure that can be used to run each version of a system in isolation and collect static and dynamic software metrics, using a lightweight virtual machine environment that can be deployed on a cluster of local or cloud machines. We use Covrig to conduct an empirical study examining how code and tests co-evolve in six popular open-source systems. We report the main characteristics of software patches, analyse the evolution of program and patch coverage, assess the impact of nondeterminism on the execution of test suites, and investigate whether the coverage of code containing bugs and bug fixes is higher than average
Maintaining a Septic Tank System
Once a septic tank and absorption field are installed, you can do several things to prolong their life, thus protecting an investment which may cost 50 or more, but it is necessary for maintaining the life of the absorption field. The contractors pump the contents into a tank truck and dispose of it at an approved treatment site or by proper land application. Be sure the workman who cleans your tank mixes the liquid, sludge and scum before pumping so that all of the material can be removed, not just the liquid. It is not recommended to wash, scrub or disinfect the septic tank when pumping. Similarly, it is not necessary to leave solids in the septic to start it again. Normally, as the septic tank fills, the natural processes begin. Products to seed the system with desirable bacteria are available, but they are also not necessary
Basic Communication Course Studentsâ Perceptions of the Purpose and Their Role in the Peer Feedback Process
Students enrolled in the basic communication course often engage in peer feedback workshops to enhance presentational speaking competence. As such, peer feedback workshops in the basic communication course provide an opportunity for students to provide and receive feedback on speech form, structure, and delivery (Broeckelman-Post & Hosek, 2014). The present study qualitatively examined data from 110 students enrolled in a basic communication course to determine their perceptions of the peer feedback process and what role(s), if any, they believed they had in the peer feedback process. Our thematic analysis revealed that studentsâ perceive peer feedback as a form of agency, influence, and skill building and perceive their role as a content editor, audience/body, and performance evaluator. Limitations and future research directions are also discussed
New Exclusion Limits for the Search of Scalar and Pseudoscalar Axion-Like Particles from "Light Shining Through a Wall"
Physics beyond the Standard Model predicts the possible existence of new
particles that can be searched at the low energy frontier in the sub-eV range.
The OSQAR photon regeneration experiment looks for "Light Shining through a
Wall" from the quantum oscillation of optical photons into "Weakly Interacting
Sub-eV Particles", such as axion or Axion-Like Particles (ALPs), in a 9 T
transverse magnetic field over the unprecedented length of m.
In 2014, this experiment has been run with an outstanding sensitivity, using an
18.5 W continuous wave laser emitting in the green at the single wavelength of
532 nm. No regenerated photons have been detected after the wall, pushing the
limits for the existence of axions and ALPs down to an unprecedented level for
such a type of laboratory experiment. The di-photon couplings of possible
pseudo-scalar and scalar ALPs can be constrained in the nearly massless limit
to be less than GeV and
GeV, respectively, at 95% Confidence Level.Comment: 6 pages, 6 figure
Revealing the molecular signatures of host-pathogen interactions.
Advances in sequencing technology and genome-wide association studies are now revealing the complex interactions between hosts and pathogen through genomic variation signatures, which arise from evolutionary co-existence
Determination of scattering lengths from measurement of atom lifetime
The DIRAC experiment at CERN has achieved a sizeable production of
atoms and has significantly improved the precision on its lifetime
determination. From a sample of 21227 atomic pairs, a 4% measurement of the
S-wave scattering length difference
has been attained, providing an important test of Chiral Perturbation Theory.Comment: 6 pages, 6 figure
Latest Results of the OSQAR Photon Regeneration Experiment for Axion-Like Particle Search
The OSQAR photon regeneration experiment searches for pseudoscalar and scalar
axion-like particles by the method of "Light Shining Through a Wall", based on
the assumption that these weakly interacting sub-eV particles couple to two
photons to give rise to quantum oscillations with optical photons in strong
magnetic field. No excess of events has been observed, which constrains the
di-photon coupling strength of both pseudoscalar and scalar particles down to
GeV in the massless limit. This result is the most
stringent constraint on the di-photon coupling strength ever achieved in
laboratory experiments.Comment: 6 pages, 5 figures. appears in Proceedings of the 10th PATRAS
Workshop on Axions, WIMPs and WISPs (2014
Diagnosis of Tuberculosis in the Wild Boar (Sus scrofa): A Comparison of Methods Applicable to Hunter-Harvested Animals
To obtain robust epidemiological information regarding tuberculosis (TB) in wildlife species, appropriate diagnostic methods need to be used. Wild boar (Sus scrofa) recently emerged as a major maintenance host for TB in some European countries. Nevertheless, no data is available to evaluate TB post-mortem diagnostic methods in hunter-harvested wild boar.
METHODOLOGY/PRINCIPAL FINDINGS:
Six different diagnostic methods for TB were evaluated in parallel in 167 hunter-harvested wild boar. Compared to bacteriological culture, estimates of sensitivity of histopathology was 77.8%, gross pathology 72.2%, PCR for the MPB70 gene 66.7%, detection of acid-fast bacilli (AFB) in tissue contact smears 55.6% and in histopathology slides 16.7% (estimated specificity was 96.7%, 100%, 100%, 94.4% and 100%, respectively). Combining gross pathology with stained smears in parallel increased estimated sensitivity to 94.4% (94.4% specificity). Four probable bacteriological culture false-negative animals were identified by Discriminant Function Analysis. Recalculating the parameters considering these animals as infected generated estimated values for sensitivity of bacteriology and histopathology of 81.8%, gross pathology 72.7%, PCR for the MPB70 gene 63.6%, detection of AFB in tissue contact smears 54.5% and in histopathology slides 13.6% (estimated specificity was 100% for gross pathology, PCR, bacteriology and detection of AFB in histopathology slides, 96.7% for histopathology and 94.4% for stained smears).
CONCLUSIONS/SIGNIFICANCE:
These results show that surveys for TB in wild boar based exclusively on gross pathology considerably underestimate prevalence, while combination of tests in parallel much improves sensitivity and negative predictive values. This finding should thus be considered when planning future surveys and game meat inspection schemes. Although bacteriological culture is the reference test for TB diagnosis, it can generate false-negative results and this should be considered when interpreting data.This study was funded by laboratory funds from Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript
Intimate partner violence and oral HIV pre-exposure prophylaxis adherence among young African women
Objective: To estimate the effect of intimate partner violence (IPV) on oral pre-exposure prophylaxis (PrEP) adherence among adolescent girls and young women (AGYW). Design: We conducted a secondary analysis of data from HIV Prevention Trials Network 082 (HPTN 082), a multisite prospective study designed to assess oral PrEP adherence among AGYW in southern Africa. Methods: We estimated the relative prevalence of high PrEP adherence 3 and 6 months after initiation among AGYW 16 â 25 years who reported a history of any IPV in the past year at enrollment versus AGYW who did not, both overall and by age. High adherence was defined as an intracellular tenofovir-diphosphate concentration at least 700 fmol/ punch or more dried blood spots. Results: Among 409 PrEP-initiating AGYW, half (49%) reported experiencing any IPV by a current/recent partner in the year prior to enrollment. Overall, a similar proportion of AGYW who reported IPV had high PrEP adherence at months 3 and 6 as AGYW who did not report IPV. There was, however, evidence of effect modification by age at month 3: among AGYW less than 21 years old, those who reported IPV were less than half as likely to have high adherence [adjusted PR (aPR) = 0.43, 95% confidence interval (CI) 0.22â 0.86]; among AGYW aged 21 years or older, those who reported IPV were more than twice as likely to have high adherence (aPR = 2.21, 95% CI 1.34â 3.66). At month 6, effect estimates within each age stratum were consistent in direction to those at month 3. Conclusion: IPV events may either impede or motivate PrEP adherence among African AGYW, with age appearing to be an important consideration for IPV-related adherence interventions
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