7,305 research outputs found
Prevention of cardiovascular disease: why do we neglect the most potent intervention?
Despite a large volume of evidence supporting its cardioprotective properties and its other numerous established health benefits, physical activity is not a serious prescription option for the primary prevention of cardiovascular disease. On the other hand, health services increasingly focus on pharmacological prevention without considering properly the long-term consequences of medication. Ethical and feasibility considerations suggest that evidence on the protective value of physical activity may need to be evaluated using criteria different from those applying to pharmacological trials. The collateral health benefits of physical activity prescription support its use as standard option in preventive health care
Physical activity education in the undergraduate curricula of all UK medical schools: are tomorrow's doctors equipped to follow clinical guidelines?
Physical activity (PA) is a cornerstone of disease prevention and treatment. There is, however, a considerable disparity between public health policy, clinical guidelines and the delivery of physical activity promotion within the National Health Service in the UK. If this is to be addressed in the battle against non-communicable diseases, it is vital that tomorrow's doctors understand the basic science and health benefits of physical activity. The aim of this study was to assess the provision of physical activity teaching content in the curricula of all medical schools in the UK. Our results, with responses from all UK medical schools, uncovered some alarming findings, showing that there is widespread omission of basic teaching elements, such as the Chief Medical Officer recommendations and guidance on physical activity. There is an urgent need for physical activity teaching to have dedicated time at medical schools, to equip tomorrow's doctors with the basic knowledge, confidence and skills to promote physical activity and follow numerous clinical guidelines that support physical activity promotion
Magneto-optical imaging of voltage-controlled magnetization reorientation
We study the validity and limitations of a macrospin model to describe the
voltage-controlled manipulation of ferromagnetic magnetization in nickel thin
film/piezoelectric actuator hybrid structures. To this end, we correlate
simultaneously measured spatially resolved magneto-optical Kerr effect imaging
and integral magnetotransport measurements at room temperature. Our results
show that a macrospin approach is adequate to model the magnetoresistance as a
function of the voltage applied to the hybrid, except for a narrow region
around the coercive field - where the magnetization reorientation evolves via
domain effects. Thus, on length scales much larger than the typical magnetic
domain size, the voltage control of magnetization is well reproduced by a
simple Stoner-Wohlfarth type macrospin model
G328.4+0.2 : A large and luminous Crab-like supernova remnant
We report on radio continuum and HI observations of the radio source
G328.4+0.2 using the Australia Telescope Compact Array. Our results confirm
G328.4+0.2 to be a filled-center nebula with no surrounding shell, showing
significant linear polarization and an almost flat spectral index. These
results lead us to conclude that G328.4+0.2 is a Crab-like, or ``plerionic'',
supernova remnant (SNR), presumably powered by an unseen central pulsar. HI
absorption towards G328.4+0.2 puts a lower limit on its distance of 17.4 +/-
0.9 kpc, making it the largest (D=25 pc) and most luminous (L_R = 3e35 erg/s)
Crab-like SNR in the Galaxy. We infer G328.4+0.2 to be significantly older than
the Crab Nebula, but powered by a pulsar which is fast spinning (P<20 ms) and
which has a comparatively low magnetic field (B<1e12 G). We propose G328.4+0.2,
G74.9+1.2 and N157B as a distinct group of large-diameter, high-luminosity
Crab-like SNRs, all powered by fast-spinning low-field pulsars.Comment: 7 pages, 3 embedded EPS figures, uses emulateapj.sty. Accepted to
ApJ. Abstract corrected so that distance is now in kpc, not pc
Pulsar "Drifting"-Subpulse Polarization: No Evidence for Systematic Polarization-Angle Rotations
Polarization-angle density displays are given for pulsars B0809+74 and
B2303+30, which exhibit no evidence of the systematic polarization-angle
rotation within individual subpulses previously reported for these two stars.
The ``drifting'' subpulses of both pulsars exhibit strikingly linear and
circular polarization which appears to reflect the characteristics of two
nearly orthogonally polarized emission ``modes''--along which the severe
average-profile depolarization that is characteristic of their admixture at
comparable overall intensities.Comment: Accepted for publication in Astronomy & Astrophysic
Recent Type II Radio Supernovae
We present the results of radio observations, taken primarily with the Very
Large Array, of Supernovae 1993J, 2001gd, 2001em, 2002hh, 2004dj, and 2004et.
We have fit a parameterized model to the multi-frequency observations of each
supernova. We compare the observed and derived radio properties of these
supernovae by optical classification and discuss the implications.Comment: 5 pages, 2 figures, 1 table Conference Proceedings: "Supernova 1987A:
20 Years After: Supernovae and Gamma-Ray Bursters" AIP, New York, eds. S.
Immler, K.W. Weiler, and R. McCra
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