High Levels of Circularly Polarized Emission from the Radio Jet in NGC 1275 (3C 84)

We present multi-frequency, high resolution VLBA circular polarization images of the radio source 3C 84 in the center of NGC 1275. Our images reveal a complex distribution of circular polarization in the inner parsec of the radio jet, with local levels exceeding 3% polarization, the highest yet detected with VLBI techniques. The circular polarization changes sign along the jet, making 3C 84 also the first radio jet to show both signs of circular polarization simultaneously. The spectrum and changing sign of the circular polarization indicate that it is unlikely to be purely intrinsic to the emitted synchrotron radiation. The Faraday conversion process makes a significant and perhaps dominant contribution to the circular polarization, and the observed spectrum suggests the conversion process is near saturation. The sign change in the circular polarization along the jet may result from this saturation or may be due to a change in magnetic field order after an apparent bend in the jet. From the small spatial scales probed here, ~ 0.15 pc, and the comparably high levels of circular polarization inferred for the intra-day variable source PKS 1519-273, we suggest a connection between small spatial scales and efficient production of circular polarization.Comment: 4 pages, accepted in ApJ Letter

Over-reassurance and undersupport after a 'false alarm': a systematic review of the impact on subsequent cancer symptom attribution and help seeking

This literature review examined research into the impact of a previous 'all-clear' or non-cancer diagnosis following symptomatic presentation ('false alarm') on symptom attribution and delays in help seeking for subsequent possible cancer symptoms

Is cancer a good way to die? A population-based survey among middle-aged and older adults in the United Kingdom

OBJECTIVES: Despite improved outcomes, cancer remains widely feared, often because of its association with a long and protracted death as opposed to the quick death that people associate with that other common cause of adult mortality: heart disease. Former editor-in-chief of the BMJ Richard Smith's view that 'cancer is the best way to die' therefore attracted much criticism. We examined middle-aged and older adults' agreement with this view and compared their attitudes towards dying from cancer versus heart disease in terms of which was a good death. METHODS: This study was part of an online survey (February 2015) in a United Kingdom (UK) population sample of 50- to 70-year olds (n = 391), with sampling quotas for gender and education. Five characteristics of 'a good death' were selected from the end-of-life literature. Respondents were asked to rate the importance of each characteristic for their own death to ensure their relevance to a population sample and the likelihood of each for death from cancer and heart disease. We also asked whether they agreed with Smith's view. RESULTS: At least 95% of respondents considered the selected five characteristics important for their own death. Death from cancer was rated as more likely to provide control over what happens (p  0.05). Almost half (40%) agreed that cancer is 'the best way to die', with no differences by age (p = 0.40), gender (p = 0.85), or education (p = 0.27). CONCLUSION: Despite the media commotion, a surprisingly high proportion of middle-aged and older adults viewed cancer as 'the best way to die' and rated cancer death as better than heart disease. Given that one in two of us are likely to be diagnosed with cancer, conversations about a good death from cancer may in a small way mitigate fear of cancer. Future research could explore variations by type of cancer or heart disease and by previous experience of these illnesses in others

MOJAVE: Monitoring of Jets in AGN with VLBA Experiments. IV. The Parent Luminosity Function of Radio-Loud Blazars

(Abridged) We use a complete sample of active galactic nuclei (AGN) selected on the basis of relativistically beamed 15 GHz radio flux density to derive the parent radio luminosity function (RLF) of bright radio-selected blazar cores. We use a maximum likelihood method to fit a beamed RLF to the observed data and thereby recover the parameters of the intrinsic (unbeamed) RLF. We analyze two subsamples of the MOJAVE sample: the first contains only objects of known FR II class, with a total of 103 sources, and the second subsample adds 24 objects of uncertain FR class for a total of 127 sources. Both subsamples exclude four known FR I radio galaxies and two gigahertz-peaked spectrum sources. We obtain good fits to both subsamples using a single power law intrinsic RLF with pure density evolution function. We find that a previously reported break in the observed MOJAVE RLF actually arises from using incomplete bins (because of the luminosity cutoff) across a steep and strongly evolving RLF, and does not reflect a break in the intrinsic RLF. The derived space density of the parent population of the FR II sources from the MOJAVE sample (with L>1.3e25 W/Hz) is approximately 1600/Gpc^3.Comment: 31 pages, 7 figures and 2 tables. Accepted for publication in ApJ. Changes: classification of sources based on radio morphology instead of optical classes; added the parameters of the RLF of the FR II sources; added more explanations; added a table listing the sample sources; added 2 extra figures related to the observed break in the RLF; updated reference

Concurrent 43 and 86 GHz Very Long Baseline Polarimetry of 3C273

We present sub-milliarcsecond resolution total intensity and linear polarization VLBI images of 3C273, using concurrent 43 and 86 GHz data taken with the Very Long Baseline Array in May 2002. The structure seen in the innermost jet suggest that we have fortuitously caught the jet in the act of changing direction. The polarization images confirm that the core is unpolarized (fractional polarization m < 1 %) at 86 GHz, but also show well ordered magnetic fields (m ~ 15 %) in the inner jet, at a projected distance of 2.3 pc from the core. In this strongly polarized region, the rotation measure changes across the jet by 4.2 x 10^{4} rad m^{-2} over an angular width of about 0.3 milliarcseconds. If the lack of polarization in the core is also attributed to a Faraday screen, then a rotation measure dispersion > 5.2 x 10^{4} rad m^{-2} must be present in or in front of that region. These are among the highest rotation measures reported so far in the nucleus of any active galaxy or quasar, and must occur outside (but probably close to) the radio emitting region. The transverse rotation measure gradient is in the same sense as that observed by Asada et al and by Zavala and Taylor at greater core distances. The magnitude of the transverse gradient decreases rapidly with distance down the jet, and appears to be variable.Comment: 4 pages, LaTeX, 3 postscript figures, submitted to Astrophysical Journal Letter

Medical student attitudes towards complementary and alternative medicine (CAM) in medical education: A critical review

© 2016 by De Gruyter. Background: This paper aims to remedy a gap in the knowledge by presenting the first critical review of the literature on major themes relating to medical students perceptions and attitudes towards the exponentially growing field of complementary and alternative medicine (CAM). Methods: After a comprehensive database search of the literature, 21 papers were chosen as suitable for the review. Results: The results from these papers were tabled and discussed. The results indicated that medical students lacked knowledge of CAM and are generally positive towards CAM education (especially in the preclinical years, if it provided evidence of efficacy and post-placement). Medical students thought that CAM should generally be incorporated into the medical curriculum mainly so they can confidently undertake referral to CAM practitioners. Being able to communicate with future patients about their CAM use was a major motivation for medical students to learn about CAM and a factor for medical student support of further incorporation of CAM content in the medical curricula. Educational exposure to CAM in many forms and in many papers was shown to significantly affect medical student attitudes to CAM. This may be reflective of the fact that, outside direct CAM training, there may be limited accessible opportunities for medical students and if integration is to occur, educational exposure is most important. Conclusions: The rise of CAM as a social and clinical phenomenon necessitates consideration of further inclusion of these topics in the medical curriculum, if future physicians are to be able to fully discharge their role as care providers in an increasingly medically pluralistic world. However, the inclusion of CAM needs to be done in an objective and critical manner, which is relevant to the learner