275 research outputs found
A note on the occurrence of root lesion nematodes under native sand-prairie plant species in the Regional Municipality of Haldimand-Norfolk, Ontario
Le nématode des lésions des racines (Pratylenchus penetrans), le nématode phytoparasite le plus important du sud de l'Ontario, possède une gamme d'hôtes extrêmement large. À cause de la nécessité de réprimer ces parasites avec des cultures recouvrantes qui sont peu ou pas hôtes, plusieurs espèces indigènes des prairies sablonneuses ont été évaluées pour leur susceptibilité au nématode des lésions. Onze espèces appartenant à quatre familles (Asclepiadaceae, Asteraceae, Poaceae et Fabaceae) ont été identifiées commes des hôtes faibles. Les populations très faibles de P. penetrans sur ces espèces indiquent qu'elles pourraient avantageusement servir comme cultures recouvrantes.The root lesion nematode Pratylenchus penetrans, which is the most important plant-parasitic nematode in southern Ontario, has an extremely wide host range. Because of the need to suppress lesion nematodes with cover-crop species which are poor or non-hosts of this parasite, a number of native sand-prairie species were evaluated for susceptibility. Eleven plant species belonging to the families Asclepiadaceae, Asteraceae, Poaceae and Fabaceae were determined to support very low numbers of P. penetrans and consequently to have potential as beneficial cover-crops
Fibrin glue obliteration is safe, effective and minimally invasive as first line treatment for pilonidal sinus disease in children
Background / Purpose: Sacrococcygeal pilonidal sinus disease (PSD) has an incidence of 1.2–2.5/1000 in children. Onset is around puberty. Symptoms of recurrent abscess and chronic suppuration may interfere with education and social integration. Treatments should cause minimal disruption while having good cure and recurrence rates. Curettage and Fibrin glue obliteration (FGO) show promising results in adults. We present our experience of its use in children.Methods: Review of all pediatric patients receiving FGO of pilonidal sinus performed by a single surgeon from September 2014 to February 2018.Results: Eighteen patients were identified. Median age was 16 (range 15–17), 55.6% were male. All procedures were completed as day cases. Median operative duration was 14 .1 (6–29) min. Twelve patients required only 1 procedure, 4 required 2 procedures, 1 required 5 procedures and 1 elected for formal excision after 2 FGO treatments. Median return to normal activities was 3 days, with 1 day school absence. Two patients developed minor surgical site infections. Median follow-up was 52 weeks (17–102), during which time there was 1 recurrence (5.6%).Conclusion: This study demonstrates FGO is a safe, effective procedure for pediatric PNS, with results comparable to off-midline flap techniques and without the need for extensive tissue excision and the associated morbidity
All-particle cosmic ray energy spectrum measured with 26 IceTop stations
We report on a measurement of the cosmic ray energy spectrum with the IceTop
air shower array, the surface component of the IceCube Neutrino Observatory at
the South Pole. The data used in this analysis were taken between June and
October, 2007, with 26 surface stations operational at that time, corresponding
to about one third of the final array. The fiducial area used in this analysis
was 0.122 km^2. The analysis investigated the energy spectrum from 1 to 100 PeV
measured for three different zenith angle ranges between 0{\deg} and 46{\deg}.
Because of the isotropy of cosmic rays in this energy range the spectra from
all zenith angle intervals have to agree. The cosmic-ray energy spectrum was
determined under different assumptions on the primary mass composition. Good
agreement of spectra in the three zenith angle ranges was found for the
assumption of pure proton and a simple two-component model. For zenith angles
{\theta} < 30{\deg}, where the mass dependence is smallest, the knee in the
cosmic ray energy spectrum was observed between 3.5 and 4.32 PeV, depending on
composition assumption. Spectral indices above the knee range from -3.08 to
-3.11 depending on primary mass composition assumption. Moreover, an indication
of a flattening of the spectrum above 22 PeV were observed.Comment: 38 pages, 17 figure
Measurements of long-range near-side angular correlations in TeV proton-lead collisions in the forward region
Two-particle angular correlations are studied in proton-lead collisions at a
nucleon-nucleon centre-of-mass energy of TeV, collected
with the LHCb detector at the LHC. The analysis is based on data recorded in
two beam configurations, in which either the direction of the proton or that of
the lead ion is analysed. The correlations are measured in the laboratory
system as a function of relative pseudorapidity, , and relative
azimuthal angle, , for events in different classes of event
activity and for different bins of particle transverse momentum. In
high-activity events a long-range correlation on the near side, , is observed in the pseudorapidity range . This
measurement of long-range correlations on the near side in proton-lead
collisions extends previous observations into the forward region up to
. The correlation increases with growing event activity and is found
to be more pronounced in the direction of the lead beam. However, the
correlation in the direction of the lead and proton beams are found to be
compatible when comparing events with similar absolute activity in the
direction analysed.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-040.htm
Evidence for the strangeness-changing weak decay
Using a collision data sample corresponding to an integrated luminosity
of 3.0~fb, collected by the LHCb detector, we present the first search
for the strangeness-changing weak decay . No
hadron decay of this type has been seen before. A signal for this decay,
corresponding to a significance of 3.2 standard deviations, is reported. The
relative rate is measured to be
, where and
are the and fragmentation
fractions, and is the branching
fraction. Assuming is bounded between 0.1 and
0.3, the branching fraction would lie
in the range from to .Comment: 7 pages, 2 figures, All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-047.htm
flavour tagging using charm decays at the LHCb experiment
An algorithm is described for tagging the flavour content at production of
neutral mesons in the LHCb experiment. The algorithm exploits the
correlation of the flavour of a meson with the charge of a reconstructed
secondary charm hadron from the decay of the other hadron produced in the
proton-proton collision. Charm hadron candidates are identified in a number of
fully or partially reconstructed Cabibbo-favoured decay modes. The algorithm is
calibrated on the self-tagged decay modes and using of data collected by the LHCb
experiment at centre-of-mass energies of and
. Its tagging power on these samples of
decays is .Comment: All figures and tables, along with any supplementary material and
additional information, are available at
http://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-027.htm
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