3,640 research outputs found
A Pair Polarimeter for Linearly Polarized High Energy Photons
A high quality beam of linearly polarized photons of several GeV will become
available with the coherent bremsstrahlung technique at JLab. We have developed
a polarimeter which requires about two meters of the beam line, has an
analyzing power of 20% and an efficiency of 0.02%. The layout and first results
of a polarimeter test on the laser back-scattering photon beam at SPring-8/LEPS
are presented
NEOExchange -- An online portal for NEO and Solar System science
Las Cumbres Observatory (LCO) has deployed a network of ten identical 1-m
telescopes to four locations. The global coverage and flexibility of the LCO
network makes it ideal for discovery, follow-up, and characterization of all
Solar System objects, and especially Near-Earth Objects (NEOs). We describe the
"LCO NEO Follow-up Network" which makes use of the LCO network of robotic
telescopes and an online, cloud-based web portal, NEOexchange, to perform
photometric characterization and spectroscopic classification of NEOs and
follow-up astrometry for both confirmed NEOs and unconfirmed NEO candidates.
The follow-up astrometric, photometric, and spectroscopic characterization
efforts are focused on those NEO targets that are due to be observed by the
planetary radar facilities and those on the NHATS lists. Astrometry allows us
to improve target orbits, making radar observations possible for objects with a
short arc or large orbital uncertainty and also allows for the detection and
measurement of the Yarkovsky effect on NEOs. Photometric & spectroscopic data
allows us to determine the light curve shape and amplitude, measure rotation
periods, determine the taxonomic classification, and improve the overall
characterization of these targets. We describe the NEOexchange follow-up portal
and the methodology adopted which allows the software to be packaged and
deployed anywhere, including in off-site cloud services. This allows
professionals, amateurs, and citizen scientists to plan, schedule and analyze
NEO imaging and spectroscopy data using the LCO network and acts as a
coordination hub for the NEO follow-up efforts. We illustrate these
capabilities with examples of first period determinations for radar-targeted
NEOs and its use to plan and execute multi-site photometric and spectroscopic
observations of (66391) 1999 KW4, the subject of the most recent planetary
defense exercise campaign.Comment: 35 pages, 6 figures, accepted by Icarus. Available on the web at
https://lco.global/neoexchange/ code available from GitHub at
https://github.com/LCOGT/neoexchange
Dependence of pp->pp pi0 near Threshold on the Spin of the Colliding Nucleons
A polarized internal atomic hydrogen target and a stored, polarized beam are
used to measure the spin-dependent total cross section Delta_sigma_T/sigma_tot,
as well as the polar integrals of the spin correlation coefficient combination
A_xx-A_yy, and the analyzing power A_y for pp-> pp pi0 at four bombarding
energies between 325 and 400 MeV. This experiment is made possible by the use
of a cooled beam in a storage ring. The polarization observables are used to
study the contribution from individual partial waves.Comment: 6 pages, 1 table, 4 figures, corrected equations 2 and
Joint Nordic prospective study on human herpesvirus 8 and multiple myeloma risk
An association between human herpesvirus 8 (HHV8) and multiple myeloma (MM) has been reported, though most studies have not confirmed such association. To follow-up on a previous prospective seroepidemiological study, where HHV8 tended to associate with MM risk, we linked five large serum banks in the Nordic countries with the Nordic cancer registries and 329 prospectively occurring cases of MM were identified, together with 1631 control subjects matched by age and gender. The HHV8 seroprevalences among cases and controls were similar (12 and 15%, respectively) and HHV8 seropositivity did not associate with the risk of MM, neither when considering positivity for lytic antibodies (relative risk (RR)=0.8, 95% confidence interval (CI)=0.5–1.1) nor for latent antibodies (RR=0.6, 95% CI=0.1–2.7). Similar risks were seen when analysis was restricted to case–control sets with at least 2 years lag before diagnosis (RR=0.8, 95% CI=0.5–1.2 and RR=0.9, 95% CI=0.1–4.2). In conclusion, the data indicate that HHV8 infection is not associated with MM
A prospective seroepidemiological study of human herpesvirus-8 infection and the risk of multiple myeloma
Presence of the Human Herpesvirus 8 (HHV8) genome has been reported in the bone marrow of multiple myeloma (MM) patients. So far, serological studies of HHV8 and MM have been inconsistent but have not included prospective epidemiological studies. We evaluated whether HHV8 infection is associated with increased risk for MM in a prospective population-based study of 39 000 Finnish subjects who donated serum samples in the period 1968–72. Serum samples from 47 subjects who developed MM during a 23-year follow-up and 224 age, area of residence and sex-matched subjects who remained healthy over a similar follow-up period were evaluated for HHV8 antibodies at enrolment, as assayed both with an immunofluorescence assay (IFA) for lytic and latent HHV8 antigens and by Western blot (WB) with three recombinant HHV8 proteins (ORFs 65, 73 and K8.1A). HHV8 seropositivity for at least one HHV8 protein on WB was found in 7% of the Finnish population and was not associated with the risk of developing MM (Relative Risk (RR) = 0.89, Confidence Interval (CI): 0.25–3.25). HHV8 seropositivity for lytic and latent antigens in the IFA was found in 16% and 0.4% of the Finnish population and tended to associate with risk of MM (RR = 2.02, CI: 0.94–4.33 and RR = 10.00, CI: 0.91–110.29, respectively). In conclusion, no statistically significant evidence for an association between HHV8 infection and the risk of future MM was found. © 2001 Cancer Research Campaign http://www.bjcancer.co
Impact of Smoking in Response to Tumor Necrosis Factor Inhibitors in Axial Spondyloarthritis : Methodologic Considerations for Longitudinal Observational Studies
We are grateful to Professor Gary Macfarlane (Chief Investigator of BSRBR-AS), the staff of the BSRBR-AS (Claudia Zabke, Elizabeth Ferguson-Jones, Maureen Heddle, Nafeesa Nazlee, and Barry Morris), and the recruiting staff at the clinical centers.Peer reviewedPostprin
Project 8 Phase III Design Concept
We present a working concept for Phase III of the Project 8 experiment,
aiming to achieve a neutrino mass sensitivity of ( C.L.)
using a large volume of molecular tritium and a phased antenna array. The
detection system is discussed in detail.Comment: 3 pages, 3 figures, Proceedings of Neutrino 2016, XXVII International
Conference on Neutrino Physics and Astrophysics, 4-9 July 2016, London, U
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