215 research outputs found
Appendicitis, mesenteric lymphadenitis, and subsequent risk of ulcerative colitis: cohort studies in Sweden and Denmark
Objective To determine whether the repeatedly observed low risk of ulcerative colitis after appendicectomy is related to the appendicectomy itself or the underlying morbidity, notably appendicitis or mesenteric lymphadenitis
Risk of Egg Parasitoid Attraction Depends on Anti-aphrodisiac Titre in the Large Cabbage White Butterfly Pieris brassicae
Males of a variety of insects transfer an anti-aphrodisiac pheromone to females during mating that renders them less attractive to conspecific males. In cabbage white butterflies, the transfer of an anti-aphrodisiac can result in the unwanted attraction of tiny egg parasitoid wasps of the genus Trichogramma that hitch-hike with mated female butterflies to a host plant where they parasitize the freshly laid butterfly eggs. Here, we show that the anti-aphrodisiac benzyl cyanide (BC) of the large cabbage white Pieris brassicae is depleted by frequent display of the mate-refusal posture that signals a female’s unreceptivity to mating. This depletion of BC is ecologically important because it results in a reduced risk of attracting the hitch-hiking egg parasitoid Trichogramma brassicae to mated female butterflies over time since mating. Our results indicate for the first time that a reduction in anti-aphrodisiac titre in mated females due to frequent adoption of the mate-refusal posture is beneficial to both mated females and males particularly when parasitoid pressure is high
Biomechanical effects of sitting with adjustable ischial and lumbar support on occupational low back pain: evaluation of sitting load and back muscle activity
Event-by-event fluctuations of the kaon to pion ratio in central Pb+Pb collisions at 158 GeV per Nucleon
We present the first measurement of fluctuations from event to event in the
production of strange particles in collisions of heavy nuclei. The ratio of
charged kaons to charged pions is determined for individual central Pb+Pb
collisions. After accounting for the fluctuations due to detector resolution
and finite number statistics we derive an upper limit on genuine
non-statistical fluctuations, perhaps related to a first or second order QCD
phase transition. Such fluctuations are shown to be very small.Comment: 4 pages, 2 figure
Baryon Stopping and Charged Particle Distributions in Central Pb+Pb Collisions at 158 GeV per Nucleon
Net proton and negative hadron spectra for central \PbPb collisions at 158
GeV per nucleon at the CERN SPS were measured and compared to spectra from
lighter systems. Net baryon distributions were derived from those of net
protons, utilizing model calculations of isospin contributions as well as data
and model calculations of strange baryon distributions. Stopping (rapidity
shift with respect to the beam) and mean transverse momentum \meanpt of net
baryons increase with system size. The rapidity density of negative hadrons
scales with the number of participant nucleons for nuclear collisions, whereas
their \meanpt is independent of system size. The \meanpt dependence upon
particle mass and system size is consistent with larger transverse flow
velocity at midrapidity for \PbPb compared to \SS central collisions.Comment: This version accepted for publication in PRL. 4 pages, 3 figures.
Typos corrected, some paragraphs expanded in response to referee comments, to
better explain details of analysi
Proceedings from the European clinical consensus conference for renal denervation: considerations on future clinical trial design
Guidelines in the management of obstructing cancer of the left colon: consensus conference of the world society of emergency surgery (WSES) and peritoneum and surgery (PnS) society
A longitudinal, multi-level comparative study of quality and safety in European hospitals: the QUASER study protocol
although there is a wealth of information available about quality improvement tools and techniques in healthcare there is little understanding about overcoming the challenges of day-to-day implementation in complex organisations like hospitals. The 'Quality and Safety in Europe by Research' (QUASER) study will investigate how hospitals implement, spread and sustain quality improvement, including the difficulties they face and how they overcome them. The overall aim of the study is to explore relationships between the organisational and cultural characteristics of hospitals and how these impact on the quality of health care; the findings will be designed to help policy makers, payers and hospital managers understand the factors and processes that enable hospitals in Europe to achieve-and sustain-high quality services for their patients
Centrality Dependence of Neutral Pion Production in 158 A GeV Pb + Pb Collisions
The production of neutral pions in 158AGeV Pb+Pb collisions has been studied
in the WA98 experiment at the CERN SPS. Transverse momentum spectra are studied
for the range 0.3 GeV/c < mT-m0 < 4.0 GeV/c. The results for central collisions
are compared to various models. The centrality dependence of the neutral pion
spectral shape and yield is investigated. An invariance of the spectral shape
and a simple scaling of the yield with the number of participating nucleons is
observed for centralities with greater than about 30 participating nucleons
which is most naturally explained by assuming an equilibrated system.Comment: 5 pages, Latex, including 3 eps figures, submitted to Phys.Rev.Lett;
updated pQCD comparison due to new input from the author, updated references,
corrected plotting error in figure
Guidelines in the management of obstructing cancer of the left colon : consensus conference of the world society of emergency surgery (WSES) and peritoneum and surgery (PnS) society
Peer reviewe
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