247 research outputs found
Climate change effects on human health: projections of temperature-related mortality for the UK during the 2020s, 2050s and 2080s
Background The most direct way in which climate change is expected to affect public health relates to changes in mortality rates associated with exposure to ambient temperature. Many countries worldwide experience annual heat-related and cold-related deaths associated with current weather patterns. Future changes in climate may alter such risks. Estimates of the likely future health impacts of such changes are needed to inform public health policy on climate change in the UK and elsewhere.
Methods Time-series regression analysis was used to characterise current temperature-mortality relationships by region and age group. These were then applied to the local climate and population projections to estimate temperature-related deaths for the UK by the 2020s, 2050s and 2080s. Greater variability in future temperatures as well as changes in mean levels was modelled.
Results A significantly raised risk of heat-related and cold-related mortality was observed in all regions. The elderly were most at risk. In the absence of any adaptation of the population, heat-related deaths would be expected to rise by around 257% by the 2050s from a current annual baseline of around 2000 deaths, and cold-related mortality would decline by 2% from a baseline of around 41 000 deaths. The cold burden remained higher than the heat burden in all periods. The increased number of future temperature-related deaths was partly driven by projected population growth and ageing.
Conclusions Health protection from hot weather will become increasingly necessary, and measures to reduce cold impacts will also remain important in the UK. The demographic changes expected this century mean that the health protection of the elderly will be vital
Vacuum Cherenkov radiation
Within the classical Maxwell-Chern-Simons limit of the Standard-Model
Extension (SME), the emission of light by uniformly moving charges is studied
confirming the possibility of a Cherenkov-type effect. In this context, the
exact radiation rate for charged magnetic point dipoles is determined and found
in agreement with a phase-space estimate under certain assumptions.Comment: 4 pages, REVTeX
Forces between electric charges in motion: Rutherford scattering, circular Keplerian orbits, action-at-a-distance and Newton's third law in relativistic classical electrodynamics
Standard formulae of classical electromagnetism for the forces between
electric charges in motion derived from retarded potentials are compared with
those obtained from a recently developed relativistic classical electrodynamic
theory with an instantaneous inter-charge force. Problems discussed include
small angle Rutherford scattering, Jackson's recent `torque paradox' and
circular Keplerian orbits. Results consistent with special relativity are
obtained only with an instantaneous interaction. The impossiblity of stable
circular motion with retarded fields in either classical electromagnetism or
Newtonian gravitation is demonstrated.Comment: 26 pages, 5 figures. QED and special relativity forbid retarded
electromagnetic forces. See also physics/0501130. V2 has typos corrected,
minor text modifications and updated references. V3 has further typos removed
and added text and reference
Gravitoelectromagnetism in a complex Clifford algebra
A linear vector model of gravitation is introduced in the context of quantum
physics as a generalization of electromagnetism. The gravitoelectromagnetic
gauge symmetry corresponds to a hyperbolic unitary extension of the usual
complex phase symmetry of electromagnetism. The reversed sign for the
gravitational coupling is obtained by means of the pseudoscalar of the
underlying complex Clifford algebra.Comment: 10 pages Latex2
Heat-related health impacts associated with the urban heat island and climate change in the West Midlands, UK
Chaotic and pseudochaotic attractors of perturbed fractional oscillator
We consider a nonlinear oscillator with fractional derivative of the order
alpha. Perturbed by a periodic force, the system exhibits chaotic motion called
fractional chaotic attractor (FCA). The FCA is compared to the ``regular''
chaotic attractor. The properties of the FCA are discussed and the
``pseudochaotic'' case is demonstrated.Comment: 20 pages, 7 figure
Mach's principle: Exact frame-dragging via gravitomagnetism in perturbed Friedmann-Robertson-Walker universes with
We show that the dragging of the axis directions of local inertial frames by
a weighted average of the energy currents in the universe is exact for all
linear perturbations of any Friedmann-Robertson-Walker (FRW) universe with K =
(+1, -1, 0) and of Einstein's static closed universe. This includes FRW
universes which are arbitrarily close to the Milne Universe, which is empty,
and to the de Sitter universe. Hence the postulate formulated by E. Mach about
the physical cause for the time-evolution of the axis directions of inertial
frames is shown to hold in cosmological General Relativity for linear
perturbations. The time-evolution of axis directions of local inertial frames
(relative to given local fiducial axes) is given experimentally by the
precession angular velocity of gyroscopes, which in turn is given by the
operational definition of the gravitomagnetic field. The gravitomagnetic field
is caused by cosmological energy currents via the momentum constraint. This
equation for cosmological gravitomagnetism is analogous to Ampere's law, but it
holds also for time-dependent situtations. In the solution for an open universe
the 1/r^2-force of Ampere is replaced by a Yukawa force which is of identical
form for FRW backgrounds with The scale of the exponential
cutoff is the H-dot radius, where H is the Hubble rate, and dot is the
derivative with respect to cosmic time. Analogous results hold for energy
currents in a closed FRW universe, K = +1, and in Einstein's closed static
universe.Comment: 23 pages, no figures. Final published version. Additional material in
Secs. I.A, I.J, III, V.H. Additional reference
Gravitomagnetism and the Clock Effect
The main theoretical aspects of gravitomagnetism are reviewed. It is shown
that the gravitomagnetic precession of a gyroscope is intimately connected with
the special temporal structure around a rotating mass that is revealed by the
gravitomagnetic clock effect. This remarkable effect, which involves the
difference in the proper periods of a standard clock in prograde and retrograde
circular geodesic orbits around a rotating mass, is discussed in detail. The
implications of this effect for the notion of ``inertial dragging'' in the
general theory of relativity are presented. The theory of the clock effect is
developed within the PPN framework and the possibility of measuring it via
spaceborne clocks is examined.Comment: 27 pages, LaTeX, submitted to Proc. Bad Honnef Meeting on: GYROS,
CLOCKS, AND INTERFEROMETERS: TESTING GENERAL RELATIVITY IN SPACE (22 - 27
August 1999; Bad Honnef, Germany
Potential health impacts from sulphur dioxide and sulphate exposure in the UK resulting from an Icelandic effusive volcanic eruption
Ash, gases and particles emitted from volcanic eruptions cause disruption to air transport, but also have negative impacts on respiratory and cardiovascular health. Exposure to sulphur dioxide (SO2) and sulphate (SO4) aerosols increases the risk of mortality, and respiratory and cardiovascular hospital admissions. Ash and gases can be transported over large distances and are a potential public health risk. In 2014–15, the Bárðarbunga fissure eruption at Holuhraun, Iceland was associated with high emissions of SO2 and SO4, detected at UK monitoring stations.
We estimated the potential impacts on the UK population from SO2 and SO4 associated with a hypothetical large fissure eruption in Iceland for mortality and emergency hospital admissions. To simulate the effects of different weather conditions, we used an ensemble of 80 runs from an atmospheric dispersion model to simulate SO2 and SO4 concentrations on a background of varying meteorology. We weighted the simulated exposure data by population, and quantified the potential health impacts that may result in the UK over a 6-week period following the start of an eruption.
We found in the majority of cases, the expected number of deaths resulting from SO2 over a 6-week period total fewer than ~100 for each model run, and for SO4, in the majority of cases, the number totals fewer than ~200. However, the 6-week simulated period with the highest SO2 was associated with 313 deaths, and the period with the highest SO4 was associated with 826 deaths. The single 6-week period relating to the highest combined SO2 and SO4 was associated with 925 deaths. Over a 5-month extended exposure period, upper estimates are for 3350 deaths, 4030 emergency cardiovascular and 6493 emergency respiratory hospitalizations. These figures represent a worst-case scenario and can inform health protection planning for effusive volcanic eruptions which may affect the UK in the future
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Can energy fluxes be used to interpret glacial/interglacial precipitation changes in the Tropics?
Recent theoretical advances in the relationship between heat transport and the position of the inter tropical convergence zone (ITCZ) present an elegant framework through which to interpret past changes in tropical precipitation patterns. Using a very large ensemble of climate model simulations we investigate whether it is possible to use this framework to interpret changes in the position of the ITCZ in response to glacial and interglacial boundary conditions. We find that the centroid of tropical precipitation, which represents the evolution of precipitation in the whole tropics, is best correlated with heat transport changes. We find that the response of the annual mean ITCZ to glacial and interglacial boundary conditions is quite different to the response of the climatological annual cycle of the ITCZ to the seasonal cycle of insolation. We show that the reason for this is that while the Hadley Circulation plays a dominant role in transporting heat over the seasonal cycle, in the annual mean response to forcing, the Hadley Circulation is not dominant. When we look regionally, rather than at the zonal mean, we find that local precipitation is poorly related to either the zonal mean ITCZ or to meridional heat transport. We demonstrate that precipitation is spatially highly variable even when the zonal mean ITCZ is in the same location. This suggests only limited use for heat transport in explaining local precipitation records, thus there is limited scope for using heat transport changes to explain individual paleo-precipitation records
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