5,434 research outputs found
Proposed New Test of Spin Effects in General Relativity
The recent discovery of a double-pulsar PSR J0737-3039A/B provides an
opportunity of unequivocally observing, for the first time, spin effects in
general relativity. Existing efforts involve detection of the precession of the
spinning body itself. However, for a close binary system, spin effects on the
orbit may also be discernable. Not only do they add to the advance of the
periastron (by an amount which is small compared to the conventional
contribution) but they also give rise to a precession of the orbit about the
spin direction. The measurement of such an effect would also give information
on the moment of inertia of pulsars
VMD, the WZW Lagrangian and ChPT: The Third Mixing Angle
We show that the Hidden Local Symmetry Model, supplemented with well-known
procedures for breaking flavor SU(3) and nonet symmetry, provides all the
information contained in the standard Chiral Perturbation Theory (ChPT)
Lagrangian . This allows to rely on radiative
decays of light mesons ( and ) in order to extract
some numerical information of relevance to ChPT: a value for , a quark mass ratio of , and a negligible
departure from the Gell-Mann--Okubo mass formula. The mixing angles are
and . We also give the values of all decay constants. It is shown that
the common mixing pattern with one mixing angle is actually quite
appropriate and algebraically related to the mixing pattern
presently preferred by the ChPT community. For instance the traditional
is functionally related to the ChPT and fulfills
. The vanishing of , supported by all
data on radiative decays, gives a novel relation between mixing angles and the
violation of nonet symmetry in the pseudoscalar sector. Finally, it is shown
that the interplay of nonet symmetry breaking through U(3) \ra SU(3)
U(1) satisfies all requirements of the physics of radiative decays without any
need for additional glueballs.Comment: 31 pages, 1 figur
Winning all the battles
Historically SpeakingRobert L. O’Connell was a member of the U.S. Intelligence
Community for thirty years, and is presently a
visiting professor at the Naval Postgraduate School.
He is the author of several books, including most recently
The Ghosts of Cannae: Hannibal and the
Darkest Hour of the Roman Republic (Random
House, 2010)
Self reported aggravating activities do not demonstrate a consistent directional pattern in chronic non specific low back pain patients: An observational study
Question: Do the self-reported aggravating activities of chronic non-specific low back pain
patients demonstrate a consistent directional pattern? Design: Cross-sectional observational
study. Participants: 240 chronic non specific low back pain patients. Outcome measure: We
invited experienced clinicians to classify each of the three self-nominated aggravating
activities from the Patient Specific Functional Scale by the direction of lumbar spine
movement. Patients were described as demonstrating a directional pattern if all nominated
activities moved the spine into the same direction. Analyses were undertaken to determine if
the proportion of patients demonstrating a directional pattern was greater than would be
expected by chance. Results: In some patients, all tasks did move the spine into the same
direction, but this proportion did not differ from chance (p = 0.328). There were no clinical or
demographic differences between those who displayed a directional pattern and those who did
not (all p > 0.05). Conclusion: Using patient self-reported aggravating activities we were
unable to demonstrate the existence of a consistent pattern of adverse movement in patients
with chronic non-specific low back pain
Viscosity of the Earth
Direct and indirect estimates of the variation of viscosity with depth in the mantle indicate that a low viscosity layer exists in the upper mantle. A viscosity varying with depth can be used to reconcile the various estimates of relaxation times. If the seismic anelasticity can be used as a guide the average viscosity of the lower mantle is about 10^(23)P. Combined with previous estimates of the upper mantle viscosity this gives a relaxation time of about 3000 years for the non-equilibrium bulge of the Earth. This is close to the time from the last ice age but is much less than the 10^7 years required if the non-equilibrium bulge is due to the changing rate of rotation which requires an average mantle viscosity of 10^(26) P. If the latter value is correct the activation volume for creep is much larger than for anelasticity or the effect of a phase change in the upper mantle is more effective in suppressing creep than attenuation.
The response of a layered viscous sphere to a surface load is calculated for a wide range of parameters including the above range of estimates for lower mantle viscosity. These results can be used to estimate the decay time, or the isostatic time scale, for various sized features
Disentanglement and Decoherence without dissipation at non-zero temperatures
Decoherence is well understood, in contrast to disentanglement. According to
common lore, irreversible coupling to a dissipative environment is the
mechanism for loss of entanglement. Here, we show that, on the contrary,
disentanglement can in fact occur at large enough temperatures even for
vanishingly small dissipation (as we have shown previously for decoherence).
However, whereas the effect of on decoherence increases exponentially with
time, the effect of on disentanglement is constant for all times,
reflecting a fundamental difference between the two phenomena. Also, the
possibility of disentanglement at a particular increases with decreasing
initial entanglement.Comment: 3 page
Coastal Blue Carbon Opportunity Assessment for Snohomish Estuary: The Climate Benefits of Estuary Restoration
This report presents the findings of a groundbreaking study that confirms the climate mitigation benefits of restoring tidal wetland habitat in the Snohomish Estuary, located within the nation's second largest estuary: Puget Sound. The study, the first of its kind, finds major climate mitigation benefits from wetland restoration and provides a much needed approach for assessing carbon fluxes for historic drained and future restored wetlands which can now be transferred and applied to other geographie
An analysis of the issues and prospects facing SriLankan Airlines and its embedded partnership with Sri Lankan tourism
The long civil war, which ended in May 2009, poor economic performance and weak travel demand for Sri Lanka all coalesced in hindering the tourism industry. Consequently its aviation industry, which is dominated by the national carrier SriLankan Airlines, faced growing and difficult challenges. However, since 2009 the country has witnessed a boom in tourism, while an unprofitable SriLankan Airlines changed its financial and strategic circumstances by becoming a member of the Oneworld alliance in mid-2014, driven by its regional geography and proximity to India which had strict bilateral traffic rights for international incumbents from the UK and the UAE. This study analyses tourism, economic and passenger data combined with results from a passenger survey and expert interviews in order to identify the critical issues and future prospects of aviation and tourism in Sri Lanka. The authors conclude that its ageing long-haul fleet, together with an inferior economy-class product along with high fuel prices, capacity constraints and poor management practices are the major issues faced by SriLankan Airlines. On the tourism side, uncompetitive hotel rates, unnecessarily high government taxes, visa charges and the lack of international promotion were seen as the principle drawbacks. A survey at Colombo airport revealed that fare is the principle rhetoric for passengers taking SriLankan Airlines but when they want a wider range of additional and superior attributes they choose foreign carriers
Projecting prevalence by stage of care for prostate cancer and estimating future health service needs: protocol for a modelling study
Introduction Current strategies for the management of prostate cancer are inadequate in Australia. We will, in this study, estimate current service needs and project the future needs for prostate cancer patients in Australia. Methods and analysis First, we will project the future prevalence of prostate cancer for 2010-2018 using data for 1972-2008 from the New South Wales (NSW) Central Cancer Registry. These projections, based on modelled incidence and survival estimates, will be estimated using PIAMOD (Prevalence, Incidence, Analysis MODel) software. Then the total prevalence will be decomposed into five stages of care: initial care, continued monitoring, recurrence, last year of life and long-term survivor. Finally, data from the NSW Prostate Cancer Care and Outcomes Study, including data on patterns of treatment and associated quality of life, will be used to estimate the type and amount of services that will be needed by prostate cancer patients in each stage of care. In addition, Central Cancer Registry episode data will be used to estimate transition rates from localised or locally advanced prostate cancer to metastatic disease. Medicare and Pharmaceutical Benefits data, linked with Prostate Cancer Care and Outcomes Study data, will be used to complement the Cancer Registry episode data. The methods developed will be applied Australia-wide to obtain national estimates of the future prevalence of prostate cancer for different stages of clinical care. Ethics and dissemination This study was approved by the NSW Population and Health Services Research Ethics Committee. Results of the study will be disseminated widely to different interest groups and organisations through a report, conference presentations and peer-reviewed articles.This work is supported by the Prostate Cancer Foundation of Australia (grant number: PCFA – YI 0410). Both David Smith and Xue Qin Yu are supported by an Australian NHMRC Training Fellowship (Ref 1016598, 550002). Mark Clements is supported by an Australian NHMRC Career Development Award (Ref 471491)
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