1,804 research outputs found
Evidence for Ordered Magnetic Fields in the Quasar Environment
At a distance of 20 pc from the purported supermassive black hole powering
quasars, temperatures and densities are inferred from optical observations to
be ~10**4 K and ~10**4 cm**-3. Here we present Very Long Baseline
Interferometry radio observations revealing organized magnetic fields on the
parsec scale in the hot plasma surrounding the quasar OQ172 (1442+101). These
magnetic fields rotate the plane of polarization of the radio emission coming
from the core and inner jet of the quasar. The derived rotation measure (RM) is
40,000 rad m**-2 in the rest frame of the quasar. Only 10 mas (a projected
distance of 68 pc) from the nucleus the jet absolute values of RM fall to less
than 100 rad m**-2.Comment: in press at ApJ Letters, 12 page LaTeX document includes 4 postscript
figure
Interim Report
Author: F. R. Rodgers for N. H. Taylor for Sage Improvement CommitteeReason: C. W. Farr reviewing for declassificationMemo regarding 1956 interim repor
Supportive Self-Management Program for People With Chronic Headaches and Migraine: A Randomized Controlled Trial and Economic Evaluation.
BACKGROUND AND OBJECTIVES: Chronic headache disorders are a major cause of pain and disability. Education and supportive self-management approaches could reduce the burden of headache disability. We tested the effectiveness of a group educational and supportive self-management program for people living with chronic headaches. METHODS: This was a pragmatic randomized controlled trial. Participants were aged 18 years or older with chronic migraine or chronic tension-type headache, with or without medication overuse headache. We primarily recruited from general practices. Participants were assigned to either a 2-day group education and self-management program, a one-to-one nurse interview, and telephone support or to usual care plus relaxation material. The primary outcome was headache related-quality of life using the Headache Impact Test (HIT)-6 at 12 months. The primary analysis used intention-to-treat principles for participants with migraine and both baseline and 12-month HIT-6 data. RESULTS: Between April 2017 and March 2019, we randomized 736 participants. Because only 9 participants just had tension-type headache, our main analyses were on the 727 participants with migraine. Of them, 376 were allocated to the self-management intervention and 351 to usual care. Data from 586 (81%) participants were analyzed for primary outcome. There was no between-group difference in HIT-6 (adjusted mean difference = -0.3, 95% CI -1.23 to 0.67) or headache days (0.9, 95% CI -0.29 to 2.05) at 12 months. The Chronic Headache Education and Self-management Study intervention generated incremental adjusted costs of ÂŁ268 (95% CI, ÂŁ176-ÂŁ377) (USD383 [95% CI USD252-USD539]) and incremental adjusted quality-adjusted life years (QALYs) of 0.031 (95% CI -0.005 to 0.063). The incremental cost-effectiveness ratio was ÂŁ8,617 (USD12,322) per QALY gained. DISCUSSION: These findings conclusively show a lack of benefit for quality of life or monthly headache days from a brief group education and supportive self-management program for people living with chronic migraine or chronic tension-type headache with episodic migraine. TRIAL REGISTRATION INFORMATION: Registered on the International Standard Randomized Controlled Trial Number registry, ISRCTN79708100 16th December 2015 doi.org/10.1186/ISRCTN79708100. The first enrollment was April 24, 2017. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that a brief group education and self-management program does not increase the probability of improvement in headache-related quality of life in people with chronic migraine
Non-pharmacological educational and self-management interventions for people with chronic headache: the CHESS research programme including a RCT
Background:
Headaches are a leading cause of years lived with disability. For some people, headaches become chronic and disabling, with treatment options being primarily pharmaceutical. Non-pharmacological alternative treatment approaches are worthy of exploration.
Aim:
To develop and test an educational and supportive self-management intervention for people with chronic headaches.
Objectives:
To develop and evaluate a brief diagnostic interview to support diagnosis for people with chronic headaches, and then to develop and pilot an education and self-management support intervention for the management of common chronic headache disorders (the CHESS intervention). To select the most appropriate outcome measures for a randomised controlled trial of the CHESS intervention, and then to conduct a randomised controlled trial and economic evaluation of the CHESS intervention with an embedded process evaluation.
Design:
Developmental and feasibility studies followed by a randomised controlled trial.
Setting:
General practice and community settings in the Midlands and London, UK.
Participants:
For our feasibility work, 14 general practices recruited 131 people with chronic headaches (headaches on â„15 days per month for >3 months). People with chronic headaches and expert clinicians developed a telephone classification interview for chronic headache that we validated with 107 feasibility study participants. We piloted the CHESS intervention with 13 participants and refined the content and structure based on their feedback. People with chronic headaches contributed to the decisions about our primary outcome and a core outcome set for chronic and episodic migraine. For the randomised controlled trial, we recruited adults with chronic migraine or chronic tension-type headache and episodic migraine, with or without medication overuse headache, from general practices and via self-referral. Our main analyses were on people with migraine.
Interventions:
The CHESS intervention consisted of two 1-day group sessions focused on education and self-management to promote behaviour change and support learning strategies to manage chronic headaches. This was followed by a one-to-one nurse consultation and telephone support. The control intervention consisted of feedback from classification interviews, headache management leaflet and a relaxation compact disc.
Main outcome measures:
The primary outcome was headache-related quality of life measured using the Headache Impact Test-6 at 12 months. The secondary outcomes included the Chronic Headache Quality of Life Questionnaire; headache days, duration and severity; EuroQol-5 Dimensions, five-level version; Short Form Questionnaire-12 items; Hospital Anxiety and Depression Scale; and Pain Self-Efficacy Questionnaire scores. We followed up participants at 4, 8 and 12 months.
Results:
Between April 2017 and March 2019, we randomised 736 participants from 164 general practices. Nine participants (1%) had chronic tension-type headache only. Our main analyses were on the remaining 727 participants with migraine (376 in the intervention arm and 351 in the usual-care arm). Baseline characteristics were well matched. For the primary outcome we had analysable data from 579 participants (80%) at 12 months. There was no between-group difference in the Headache Impact Test-6 at 12 months, (adjusted mean difference â0.3, 95% confidence interval â1.23 to 0.67; p = 0.56). The limits of the 95% confidence interval effectively exclude the possibility of the intervention having a worthwhile benefit. At 4 months there was a difference favouring the CHESS self-management programme on the Headache Impact Test-6 (adjusted mean difference â1.0, 95% confidence interval â1.91 to â0.006; p = 0.049). However, the self-management group also reported 1.5 (95% confidence interval 0.48 to 2.56) more headache days in the previous 28 days. Apart from improved pain self-efficacy at 4 and 12 months, there were few other statistically significant between-group differences in the secondary outcomes. The CHESS intervention generated 0.031 (95% confidence interval â0.005 to 0.063) additional quality-adjusted life-years and increased NHS and Personal Social Services costs by ÂŁ268 (95% confidence interval ÂŁ176 to ÂŁ377), on average, generating an incremental cost-effectiveness ratio of ÂŁ8617 with an 83% chance of being cost-effective at a willingness-to-pay threshold of ÂŁ20,000 per quality-adjusted life-year. The CHESS intervention was well received and fidelity was good. No process-related issues were identified that would explain why the intervention was ineffective.
Limitations:
Only 288 out of 376 (77%) of those randomised to the CHESS intervention attended one or more of the intervention sessions.
Conclusions:
This short, non-pharmacological, educational self-management intervention is unlikely to be effective for the treatment of people with chronic headaches and migraine.
Future work:
There is a need to develop and test more sustained non-pharmacological interventions for people with chronic headache disorders.
Patient and public involvement:
Substantial patient and public involvement went into the design, conduct and interpretation of the CHESS programme. This helped direct the research and ensured that the patient voice was embedded in our work.
Trial registration:
This trial is registered as ISRCTN79708100.
Funding:
This project was funded by the National Institute for Health and Care Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 11, No. 2. See the NIHR Journals Library website for further information
Supportive Self-Management Program for People With Chronic Headaches and Migraine: A Randomized Controlled Trial and Economic Evaluation
Background and Objectives: Chronic headache disorders are a major cause of pain and disability. Education and supportive self-management approaches could reduce the burden of headache disability. We tested the effectiveness of a group educational and supportive self-management program for people living with chronic headaches. / Methods: This was a pragmatic randomized controlled trial. Participants were aged 18 years or older with chronic migraine or chronic tension-type headache, with or without medication overuse headache. We primarily recruited from general practices. Participants were assigned to either a 2-day group education and self-management program, a one-to-one nurse interview, and telephone support or to usual care plus relaxation material. The primary outcome was headache related-quality of life using the Headache Impact Test (HIT)-6 at 12 months. The primary analysis used intention-to-treat principles for participants with migraine and both baseline and 12-month HIT-6 data. / Results: Between April 2017 and March 2019, we randomized 736 participants. Because only 9 participants just had tension-type headache, our main analyses were on the 727 participants with migraine. Of them, 376 were allocated to the self-management intervention and 351 to usual care. Data from 586 (81%) participants were analyzed for primary outcome. There was no between-group difference in HIT-6 (adjusted mean difference = -0.3, 95% CI -1.23 to 0.67) or headache days (0.9, 95% CI -0.29 to 2.05) at 12 months. The Chronic Headache Education and Self-management Study intervention generated incremental adjusted costs of ÂŁ268 (95% CI, ÂŁ176-ÂŁ377) (USD383 [95% CI USD252-USD539]) and incremental adjusted quality-adjusted life years (QALYs) of 0.031 (95% CI -0.005 to 0.063). The incremental cost-effectiveness ratio was ÂŁ8,617 (USD12,322) per QALY gained. / Discussion: These findings conclusively show a lack of benefit for quality of life or monthly headache days from a brief group education and supportive self-management program for people living with chronic migraine or chronic tension-type headache with episodic migraine
The Universe Was Reionized Twice
We show the universe was reionized twice, first at z~15-16 and second at z~6.
Such an outcome appears inevitable, when normalizing to two well determined
observational measurements, namely, the epoch of the final cosmological
reionization at z~6 and the density fluctuations at z~6, which in turn are
tight ly constrained by Lyman alpha forest observations at z~3. These two
observations most importantly fix the product of star formation efficiency and
ionizing photon escape fraction from galaxies at high redshift. To the extent
that the relative star formation efficiencies in gaseous minihalos with H2
cooling and large halos with atomic cooling at high redshift are still unknown,
the primary source for the first reionization could be Pop III stars either in
minihalos or in large halos. We show that gas in minihalos can be cooled
efficiently by H2 molecules and star formation can continue to take place
largely unimpeded throughout the first reionization period, thanks to two new
mechanisms for generating a high X-ray background during the Pop III era, put
forth here. Moreover, an important process for producing a large number of H2
molecules in relic HII regions of Pop III galaxies, first pointed out by
Ricotti, Gnedin, & Shull, is quantified here. It is shown that the Lyman-Werner
background may never build up during the Pop III era. The long cosmological
reionization and reheating history is complex. We discuss a wide range of
implications and possible tests for this new reionization picture. In
particular, Thomson scattering optical depth is increased to 0.10 +- 0.03,
compared to 0.027 for the case of only one rapid reionization at z=6. Upcoming
Microwave Anisotropy Probe observation of the polarization of the cosmic
microwave background should be able to distinguish between these two scenarios.Comment: submitted to ApJ, 69 pages, substantial revision made and conclusions
strengthene
Quality of life, characteristics and survival of patients with HIV and lymphoma
We sought to compare the quality of life (QOL), characteristics, and survival of patients with non-Hodgkin lymphoma (NHL) with and without human immunodeficiency virus (HIV) infection.
Using the population-based cancer registry for Orange and San Diego Counties, We recruited 50 patients with HIV and systemic NHL (cases) and 50 age, sex and race-matched NHL patients without HIV (controls) diagnosed with NHL during 2002â2006. Patients completed a medical history survey and QOL instrument, the Functional Assessment of Human Immunodeficiency Virus Infection (FAHI) for cases and Functional Assessment of Cancer Therapy-General (FACT G) for controls.
HIV-infected patients had worse overall QOL and survival than uninfected patients. QOL differences were more marked in the areas of functional, physical and social well-being than in the area of emotional well-being. HIV-infected patients had lower income and were less likely to have private insurance and more likely to have diffuse large B cell histology than uninfected patients.
HIV-infected NHL patients had worse QOL and survival than uninfected patients, due to a combination of co-morbidity, aggressive histology and lack of social support. However, their emotional well-being was comparable to that of uninfected NHL patients and better than historical norms for the HIV-infected
On the cosmic ray bound for models of extragalactic neutrino production
We obtain the maximum diffuse neutrino intensity predicted by hadronic
photoproduction models of the type which have been applied to the jets of
active galactic nuclei or gamma ray bursts. For this, we compare the proton and
gamma ray fluxes associated with hadronic photoproduction in extragalactic
neutrino sources with the present experimental upper limit on cosmic ray
protons and the extragalactic gamma ray background, employing a transport
calculation of energetic protons traversing cosmic photon backgrounds. We take
into account the effects of the photon spectral shape in the sources on the
photoproduction process, cosmological source evolution, the optical depth for
cosmic ray ejection, and discuss the possible effects of magnetic fields in the
vicinity of the sources. For photohadronic neutrino sources which are optically
thin to the emission of neutrons we find that the cosmic ray flux imposes a
stronger bound than the extragalactic gamma ray background in the energy range
between 10^5 GeV and 10^11 GeV, as previously noted by Waxman & Bahcall (1999).
We also determine the maximum contribution from the jets of active galactic
nuclei, using constraints set to their neutron opacity by gamma-ray
observations. This present upper limit is consistent with the jets of active
galactic nuclei producing the extragalactic gamma ray background hadronically,
but we point out future observations in the GeV-to-TeV regime could lower this
limit. We also briefly discuss the contribution of gamma ray bursts to
ultra-high energy cosmic rays as it can be inferred from possible observations
or limits on their correlated neutrino fluxes.Comment: 16 pages, includes 7 figures, using REVtex3.1, accepted for
publication in Phys.Rev.D after minor revision
What turns galaxies off? The different morphologies of star-forming and quiescent galaxies since z~2 from CANDELS
We use HST/WFC3 imaging from the CANDELS Multicycle Treasury Survey, in
conjunction with the Sloan Digital Sky Survey, to explore the evolution of
galactic structure for galaxies with stellar masses >3e10M_sun from z=2.2 to
the present epoch, a time span of 10Gyr. We explore the relationship between
rest-frame optical color, stellar mass, star formation activity and galaxy
structure. We confirm the dramatic increase from z=2.2 to the present day in
the number density of non-star-forming galaxies above 3e10M_sun reported by
others. We further find that the vast majority of these quiescent systems have
concentrated light profiles, as parametrized by the Sersic index, and the
population of concentrated galaxies grows similarly rapidly. We examine the
joint distribution of star formation activity, Sersic index, stellar mass,
inferred velocity dispersion, and stellar surface density. Quiescence
correlates poorly with stellar mass at all z<2.2. Quiescence correlates well
with Sersic index at all redshifts. Quiescence correlates well with `velocity
dispersion' and stellar surface density at z>1.3, and somewhat less well at
lower redshifts. Yet, there is significant scatter between quiescence and
galaxy structure: while the vast majority of quiescent galaxies have prominent
bulges, many of them have significant disks, and a number of bulge-dominated
galaxies have significant star formation. Noting the rarity of quiescent
galaxies without prominent bulges, we argue that a prominent bulge (and
perhaps, by association, a supermassive black hole) is an important condition
for quenching star formation on galactic scales over the last 10Gyr, in
qualitative agreement with the AGN feedback paradigm.Comment: The Astrophysical Journal, in press; 20 pages with 13 figure
Spin Correlation in tt-bar Production from pp-bar Collisions at sqrt(s)=1.8 TeV
The D0 collaboration has performed a study of spin correlation in tt-bar
production for the process tt-bar to bb-bar W^+W^-, where the W bosons decay to
e-nu or mu-nu. A sample of six events was collected during an exposure of the
D0 detector to an integrated luminosity of approximately 125 pb^-1 of
sqrt{s}=1.8 TeV pp-bar collisions. The standard model (SM) predicts that the
short lifetime of the top quark ensures the transmission of any spin
information at production to the tt-bar decay products.
The degree of spin correlation is characterized by a correlation coefficient
k. We find that k>-0.25 at the 68% confidence level, in agreement with the SM
prediction of k=0.88.Comment: Submitted to PRL, Added references, minor changes to tex
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