248 research outputs found
Adopting Agile Practices when Developing Medical Device Software
Agile methods are gaining momentum amongst the developers of non-safety critical software. They offer the ability to improve development time, increase quality and reduce development costs. Despite this, the rate of adoption of agile methods within safety critical domains remains low. On face value agile methods appear to be contradictory to regulatory requirements. However while they may appear contradictory, they align on key values such as the development of the highest quality software. To demonstrate that agile methods could in fact be adopted when developing regulatory compliant software they were implemented on a medical device software development project. This implementation showed that not only can agile methods be successfully followed, but it also revealed that benefits were acquired. For example, the medical device software development project was completed 7% faster when following agile methods, when compared to if it had been completed in accordance with a plan-driven approach. While this implementation is confined to a single project, within a single organization it does strengthen the belief that adopting agile methods within regulated domains can reap the same benefits as those acquired in non-safety critical domains
Untying the Gaullian knot: France and the struggle to overcome the Cold War order, 1963-1968.
On 14 January 1963, French President General Charles de Gaulle shook the Western world. During a press conference, he announced that France was not only vetoing the British application to join the European Economic Community, but that it was also rejecting US President John F. Kennedy's proposal to integrate the French nuclear de frappe into the Multilateral Force. In the aftermath of the Algerian War, De Gaulle's spectacular double non was meant to signal the shift to a more ambitious diplomatic agenda, which centred on the twin aims of recapturing France's Great Power status, and striving to overcome the Cold War bipolar order. In the next five years, France placed itself at the forefront of international affairs through a series of bold initiatives that affected all areas of the world. Yet, by the summer 1968, the General's grand design was effectively in ruins, following a series of domestic and international setbacks. Despite the fact that there is vast literature on the subject, there are still important divisions when it comes to assessing the exact intentions of the French President. Was he primarily pursuing revisionist goals, or was he in fact more interested by traditional Great Power interests. Was De Gaulle anti-American. This dissertation aims to present a more nuanced picture of French foreign policy between 1963 and 1968. It will attempt, thanks to its multi-archival and multi-national research, to place Paris' actions in a more international context. It will further argue that the General's grand design is best understood by underlining the role of linkages, which is to say by systematically studying the interactions between the various policy spheres, rather than considering them in isolation
Transatlantic relations and European strategic autonomy in the Biden era: Neglect, primacy or reform?
Faecalibacterium Gut Colonization Is Accelerated by Presence of Older Siblings
ABSTRACT Faecalibacterium prausnitzii is a highly abundant human gut microbe in healthy individuals, but it is present at reduced levels in individuals with gastrointestinal inflammatory diseases. It has therefore been suggested to constitute a marker of a healthy gut and is associated with anti-inflammatory properties. However, factors affecting the colonization of F. prausnitzii in the human gut during early life are very poorly understood. By analysis of 16S rRNA amplicon sequencing data from three separate infant study populations, we determined the colonization dynamics of Faecalibacterium and factors affecting its establishment in the gut. We found that in particular, the presence of older siblings was consistently associated with Faecalibacterium gut colonization during late infancy and conclude that acquisition of Faecalibacterium is very likely to be accelerated through transfer between siblings. IMPORTANCE Faecalibacterium prausnitzii has been suggested to constitute a key marker of a healthy gut, yet the factors shaping the colonization of this highly oxygen-sensitive, non-spore-forming species in the intestinal environment remain poorly understood. Here, we provide evidence from three separate infant study populations that F. prausnitzii colonization in the gut happens during late infancy and is affected by the number of older siblings in the family. We conclude that Faecalibacterium acquisition is highly likely to be accelerated by contact between siblings. Bearing in mind the immunoregulatory properties of F. prausnitzii and the well-established protective effects against allergic disorders related to the presence of older siblings, early colonization of this species may have profound consequences for child health
Results from Bottomonia Production at the Tevatron and Prospects for the LHC
We extend our previous analysis on inclusive heavy quarkonia hadroproduction
to the whole Upsilon(nS) (n=1,2,3) resonance family. We use a Monte Carlo
framework with the colour-octet mechanism implemented in the PYTHIA event
generator. We include in our study higher order QCD effects such as
initial-state emission of gluons and Altarelli-Parisi evolution of final-state
gluons. We extract some NRQCD colour-octet matrix elements relevant for
Upsilon(nS) (n=1,2,3) hadroproduction from CDF data at the Fermilab Tevatron.
Then we extrapolate to LHC energies to predict prompt bottomonia production
rates. Finally, we examine the prospect to probe the gluon density in protons
from heavy quarkonia inclusive hadroproduction at high transverse momentum and
its feasibility in LHC general-purpose experiments.Comment: LaTeX, 30 pages, 30 EPS figure
Blazars in the Fermi Era: The OVRO 40-m Telescope Monitoring Program
The Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope
provides an unprecedented opportunity to study gamma-ray blazars. To capitalize
on this opportunity, beginning in late 2007, about a year before the start of
LAT science operations, we began a large-scale, fast-cadence 15 GHz radio
monitoring program with the 40-m telescope at the Owens Valley Radio
Observatory (OVRO). This program began with the 1158 northern (declination>-20
deg) sources from the Candidate Gamma-ray Blazar Survey (CGRaBS) and now
encompasses over 1500 sources, each observed twice per week with a ~4 mJy
(minimum) and 3% (typical) uncertainty. Here, we describe this monitoring
program and our methods, and present radio light curves from the first two
years (2008 and 2009). As a first application, we combine these data with a
novel measure of light curve variability amplitude, the intrinsic modulation
index, through a likelihood analysis to examine the variability properties of
subpopulations of our sample. We demonstrate that, with high significance
(7-sigma), gamma-ray-loud blazars detected by the LAT during its first 11
months of operation vary with about a factor of two greater amplitude than do
the gamma-ray-quiet blazars in our sample. We also find a significant (3-sigma)
difference between variability amplitude in BL Lacertae objects and
flat-spectrum radio quasars (FSRQs), with the former exhibiting larger
variability amplitudes. Finally, low-redshift (z<1) FSRQs are found to vary
more strongly than high-redshift FSRQs, with 3-sigma significance. These
findings represent an important step toward understanding why some blazars emit
gamma-rays while others, with apparently similar properties, remain silent.Comment: 23 pages, 24 figures. Submitted to ApJ
A Cautionary Tale: MARVELS Brown Dwarf Candidate Reveals Itself To Be A Very Long Period, Highly Eccentric Spectroscopic Stellar Binary
We report the discovery of a highly eccentric, double-lined spectroscopic
binary star system (TYC 3010-1494-1), comprising two solar-type stars that we
had initially identified as a single star with a brown dwarf companion. At the
moderate resolving power of the MARVELS spectrograph and the spectrographs used
for subsequent radial-velocity (RV) measurements (R ~ <30,000), this particular
stellar binary mimics a single-lined binary with an RV signal that would be
induced by a brown dwarf companion (Msin(i)~50 M_Jup) to a solar-type primary.
At least three properties of this system allow it to masquerade as a single
star with a very low-mass companion: its large eccentricity (e~0.8), its
relatively long period (P~238 days), and the approximately perpendicular
orientation of the semi-major axis with respect to the line of sight (omega~189
degrees). As a result of these properties, for ~95% of the orbit the two sets
of stellar spectral lines are completely blended, and the RV measurements based
on centroiding on the apparently single-lined spectrum is very well fit by an
orbit solution indicative of a brown dwarf companion on a more circular orbit
(e~0.3). Only during the ~5% of the orbit near periastron passage does the
true, double-lined nature and large RV amplitude of ~15 km/s reveal itself. The
discovery of this binary system is an important lesson for RV surveys searching
for substellar companions; at a given resolution and observing cadence, a
survey will be susceptible to these kinds of astrophysical false positives for
a range of orbital parameters. Finally, for surveys like MARVELS that lack the
resolution for a useful line bisector analysis, it is imperative to monitor the
peak of the cross-correlation function for suspicious changes in width or
shape, so that such false positives can be flagged during the candidate vetting
process.Comment: 16 pages, 11 figures, 6 table
Modeling accuracy as a function of response time with the generalised linear mixed effects model
In psycholinguistic studies using error rates as a response measure, response times (RT) are most often analyzed independently of the error rate, although it is widely recognized that they are related. In this paper we present a mixed effects logistic regression model for the error rate that uses RT as a trial-level fixed- and random-effect regression input. Production data from a translation–recall experiment are analyzed as an example. Several model comparisons reveal that RT improves the fit of the regression model for the error rate. Two simulation studies then show how the mixed effects regression model can identify individual participants for whom (a) faster responses are more accurate, (b) faster responses are less accurate, or (c) there is no relation between speed and accuracy. These results show that this type of model can serve as a useful adjunct to traditional techniques, allowing psycholinguistic researchers to examine more closely the relationship between RT and accuracy in individual subjects and better account for the variability which may be present, as well as a preliminary step to more advanced RT–accuracy modeling
Unified time analysis of photon and (nonrelativistic) particle Tunnelling, and the Superluminal group-velocity problem
A unified approach to the time analysis of tunnelling of nonrelativistic
particles is presented, in which Time is regarded as a quantum-mechanical
observable, canonically conjugated to Energy. The validity of the Hartman
effect (independence of the Tunnelling Time of the opaque barrier width, with
Superluminal group velocities as a consequence) is verified for ALL the known
expressions of the mean tunnelling time. Moreover, the analogy between particle
and photon tunnelling is suitably exploited. On the basis of such an analogy,
an explanation of some recent microwave and optics experimental results on
tunnelling times is proposed. Attention is devoted to some aspects of the
causality problem for particle and photon tunnelling.Comment: plain (old) LaTeX; 42 pages; plus figures 1, 2, 3, 4a, 4b, and
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