2,291 research outputs found
Autonomous agile teams: Challenges and future directions for research
According to the principles articulated in the agile manifesto, motivated and
empowered software developers relying on technical excellence and simple
designs, create business value by delivering working software to users at
regular short intervals. These principles have spawned many practices. At the
core of these practices is the idea of autonomous, self-managing, or
self-organizing teams whose members work at a pace that sustains their
creativity and productivity. This article summarizes the main challenges faced
when implementing autonomous teams and the topics and research questions that
future research should address
Grazing Management of Tagasaste (Chamaecytisus Proliferus) for Sheep and Cattle Production in Southern Australia
Direct grazing of hedgerows of tagasaste (Chamaecytisus proliferus) by sheep or cattle appear to be very robust systems. Tagasaste persists under a continuous grazing regime with cattle such that plant regrowth maintained between 5 and 10 cm in length produces in excess of 215 kg of animal liveweight/ha/year. This level of production is also sustained within a rotational grazing regime. Under both grazing systems cattle production within a year is highly seasonal, with liveweight gains from young cattle peaking at 1.0-1.5 kg/head/day in winter and spring, but dropping to maintenance only by late summer-autumn. Sheep, like cattle, can be grazed on tagasaste at any time of the year, however their different grazing habits demand sheep be used in an intensive, short-term grazing system for approximately 30 days at a time on any one stand of tagasaste
Association of the Covid-19 lockdown with smoking, drinking, and attempts to quit in England: an analysis of 2019-2020 data
Aim: To examine changes in smoking, drinking and quitting/reduction behaviour following the COVIDâ19 lockdown in
England. Design/setting: Monthly crossâsectional surveys representative of the adult population in England,
aggregated before (April 2019âFebruary 2020) versus after (April 2020) lockdown. Participants: A total of 20 558
adults (â„ 16 years). Measurements: The independent variable was the timing of the COVIDâ19 lockdown (before versus
after March 2020). Dependent variables were: prevalence of smoking and highârisk drinking, pastâyear cessation and quit
attempts (among pastâyear smokers), pastâyear attempts to reduce alcohol consumption (among highârisk drinkers) and
use of evidenceâbased (e.g. prescription medication/faceâtoâface behavioural support) and remote support [telephone
support/websites/applications (apps)] for smoking cessation and alcohol reduction (among smokers/highârisk drinkers
who made a quit/reduction attempt). Covariates included age, sex, social grade, region and level of nicotine and alcohol
dependence (as relevant). Findings: The COVIDâ19 lockdown was not associated with a significant change in smoking
prevalence [17.0% (after) versus 15.9% (before), odds ratio (OR) = 1.09, 95% CI = 0.95â1.24], but was associated with
increases in quit attempts [39.6 versus 29.1%, adjusted odds ratio (ORadj) = 1.56, 95% CI = 1.23â1.98], quit success
(21.3 versus 13.9%, ORadj = 2.01, 95% CI = 1.22â3.33) and cessation (8.8 versus 4.1%, ORadj = 2.63, 95%
CI = 1.69â4.09) among pastâyear smokers. Among smokers who tried to quit, there was no significant change in use
of evidenceâbased support (50.0 versus 51.5%, ORadj = 1.10, 95% CI = 0.72â1.68) but use of remote support increased
(10.9 versus 2.7%, ORadj = 3.59, 95% CI = 1.56â8.23). Lockdown was associated with increases in highârisk drinking
(38.3 versus 25.1%, OR = 1.85, CI = 1.67â2.06), but also alcohol reduction attempts by highârisk drinkers (28.5 versus
15.3%, ORadj = 2.16, 95% CI = 1.77â2.64). Among highârisk drinkers who made a reduction attempt, use of
evidenceâbased support decreased (1.2 versus 4.0%, ORadj = 0.23, 95% CI = 0.05â0.97) and there was no significant
change in use of remote support (6.9 versus 6.1%, ORadj = 1.32, 95% CI = 0.64â2.75). Conclusions: Following the
March 2020 COVIDâ19 lockdown, smokers and highârisk drinkers in England were more likely than before lockdown to
report trying to quit smoking or reduce alcohol consumption and rates of smoking cessation and use of remote cessation
support were higher. However, highârisk drinking prevalence increased postâlockdown and use of evidenceâbased support
for alcohol reduction by highârisk drinkers decreased with no compensatory increase in use of remote support
Effect of Radiation Exposure on the Retention of Commercial NAND Flash Memory
We have compared the data retention of irradiated commercial NAND flash memories with that of unirradiated controls. Under some circumstanc es, radiation exposure has a significant effect on the retention of f lash memories
Factors associated with drinking behaviour during COVID-19 social distancing and lockdown among adults in the UK
Aim: To assess what factors were associated with reported changes to usual alcohol drinking behaviour during the start of lockdown in the UK. /
Design: Online cross-sectional survey from 21st March to 4th April 2020. /
Setting: UK. /
Participants: 30,375 adults aged â„ 18y. /
Measurements: Changes in drinking over the past week, sociodemographic characteristics, diagnosed or suspected COVID-19, adherence to COVID-19 protective behaviours, stress about COVID-19, finances or boredom, recent drop in household income, key worker status, and health conditions. /
Findings: Of 22,113 drinkers (65.7% of analytic sample), 48.1% (95% CI=47.0-49.1%) reported drinking about the same as usual, 25.7% (24.8-26.6%) reported drinking less than usual, and 26.2% (25.4-27.1%) reported drinking more than usual over the past week. Drinking less than usual was independently associated with being younger (OR=0.88 [95% CI=0.83-0.93]), male (OR=0.76 [0.68-0.84]), of an ethnic minority (OR=0.76 [0.61-0.97]), low annual household income (OR=0.74 [0.66-0.83]), having diagnosed or suspected COVID-19 (OR=2.04 [1.72-2.41]), adhering to COVID-19 protective behaviours (OR=1.58 [1.08-2.32]), being significantly stressed about becoming seriously ill from COVID-19 (OR=1.26 [1.08-1.48]) and not being a key worker (OR=0.87 [0.76-0.99]). Drinking more than usual was independently associated with being younger (OR=0.73 [0.69-0.78]), female (OR=1.36 [1.22-1.51]), post-16 qualifications (OR=1.21 [1.04-1.40]), high annual household income (OR=1.43 [1.27-1.61]), being significantly stressed about catching (OR=1.22 [1.03-1.45]) or becoming seriously ill from COVID-19 (OR=1.28 [1.10-1.48]), being significantly stressed about finances (OR=1.43 [1.24-1.66]), and having a diagnosed anxiety disorder (OR=1.24 [1.05-1.46]). /
Conclusions: In a representative sample of adults in the UK, about half of drinkers reported drinking the same amount of alcohol as usual during the start of the COVID-19 related lockdown, with a quarter drinking more and a quarter drinking less than usual. Drinking more than usual was associated with being younger, female, high socioeconomic position, having an anxiety disorder, and being stressed about finances or COVID-19. These groups may benefit targeted alcohol reduction support if there are further periods of lockdown. /
Registration: The analysis plan was pre-registered on Open Science Framework (https://osf.io/pnrhq/)
Using the fractional interaction law to model the impact dynamics in arbitrary form of multiparticle collisions
Using the molecular dynamics method, we examine a discrete deterministic
model for the motion of spherical particles in three-dimensional space. The
model takes into account multiparticle collisions in arbitrary forms. Using
fractional calculus we proposed an expression for the repulsive force, which is
the so called fractional interaction law. We then illustrate and discuss how to
control (correlate) the energy dissipation and the collisional time for an
individual article within multiparticle collisions. In the multiparticle
collisions we included the friction mechanism needed for the transition from
coupled torsion-sliding friction through rolling friction to static friction.
Analysing simple simulations we found that in the strong repulsive state binary
collisions dominate. However, within multiparticle collisions weak repulsion is
observed to be much stronger. The presented numerical results can be used to
realistically model the impact dynamics of an individual particle in a group of
colliding particles.Comment: 17 pages, 8 figures, 1 table; In review process of Physical Review
Factorial Moments of Continuous Order
The normalized factorial moments are continued to noninteger values of
the order , satisfying the condition that the statistical fluctuations
remain filtered out. That is, for Poisson distribution for all .
The continuation procedure is designed with phenomenology and data analysis in
mind. Examples are given to show how can be obtained for positive and
negative values of . With being continuous, multifractal analysis is
made possible for multiplicity distributions that arise from self-similar
dynamics. A step-by-step procedure of the method is summarized in the
conclusion.Comment: 15 pages + 9 figures (figures available upon request), Late
Release of dissolved organic carbon from seagrass wrack and its implications for trophic connectivity
ABSTRACT: The export of old leaves and stems (wrack) from seagrass meadows provides a mechanism for trophic connectivity among coastal ecosystems. As little of this wrack is consumed by mesograzers, leached dissolved organic carbon (DOC) may determine the importance of wrack as a trophic subsidy. However, few studies have examined the effect of seagrass type or age on the release of DOC or its bioavailability. We examined the amount and composition of DOC released from different wrack: Posidonia sinuosa, Amphibolis antarctica and the alga Laurencia sp. We then examined the effect of age on DOC leaching from P. sinuosa wrack. The bioavailability of the DOC was also assessed using a bacterial bioassay. The rate of DOC leaching from P. sinuosa leaves decreased exponentially with time. According to that exponential model, ~50% of the total DOC release occurred in the first 14 d and it would require a further 2.94 yr to release the same amount again. Fresh algae Laurencia sp. leached the greatest amount of DOC in the first 16 h (6.7 g kg-1 fresh weight (FW) wrack), followed by fresh P. sinuosa leaves (1.7 g kg-1 FW), A. antarctica leaves (1.1 g kg-1) and stems (0.6 g kg-1), 4 wk old P. sinuosa (67 g kg-1) and fine detritus (74 g kg-1). In all cases, the composition of the DOC was similar and dominated by the hydrophilic component (in P. sinuosa, predominantly sugars and amino acids). Leachates from all fresh wrack supported bacterial growth over 24 h. Leachate from older wrack either failed to support bacterial growth or only supported it for a limited time. Given the exponential decay in DOC release rate, the interacting timescales of transport and leaching will affect the value of wrack as a vector for trophic subsidies
Spectral Asymptotics of Eigen-value Problems with Non-linear Dependence on the Spectral Parameter
We study asymptotic distribution of eigen-values of a quadratic
operator polynomial of the following form ,
where is a second order differential positive elliptic operator
with quadratic dependence on the spectral parameter . We derive
asymptotics of the spectral density in this problem and show how to compute
coefficients of its asymptotic expansion from coefficients of the asymptotic
expansion of the trace of the heat kernel of . The leading term in
the spectral asymptotics is the same as for a Laplacian in a cavity. The
results have a number of physical applications. We illustrate them by examples
of field equations in external stationary gravitational and gauge backgrounds.Comment: latex, 20 page
Fractional dynamics of coupled oscillators with long-range interaction
We consider one-dimensional chain of coupled linear and nonlinear oscillators
with long-range power-wise interaction. The corresponding term in dynamical
equations is proportional to . It is shown that the
equation of motion in the infrared limit can be transformed into the medium
equation with the Riesz fractional derivative of order , when
. We consider few models of coupled oscillators and show how their
synchronization can appear as a result of bifurcation, and how the
corresponding solutions depend on . The presence of fractional
derivative leads also to the occurrence of localized structures. Particular
solutions for fractional time-dependent complex Ginzburg-Landau (or nonlinear
Schrodinger) equation are derived. These solutions are interpreted as
synchronized states and localized structures of the oscillatory medium.Comment: 34 pages, 18 figure
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