89,934 research outputs found
The impact of income shocks on health: evidence from cohort data
We study the effect of permanent income innovations on health for a prime-aged population. Using information
on more than half a million individuals sampled over a twenty-five year period in three different cross-sectional
surveys we aggregate data by date-of-birth cohort to construct a ’synthetic cohort’ dataset with details of income, expenditure, socio-demographic factors, health outcomes and selected risk factors. We then exploit structural and arguably exogenous changes in cohort incomes over the eighties and nineties to uncover causal effects of
permanent income shocks on health. We find that such income innovations have little effects on health, but do
affect health behaviour and mortality
From life cycle talking to taking action
Introduction - The biannual Life Cycle Management conference series aims to create a platform for users and developers of Life Cycle Assessment (LCA) and related tools to share their experiences. A key concern of the LCM community has been to move beyond the production of LCA reports toward using the developed knowledge. This paper reports and evaluates some of the main outcomes of the 4th International Life Cycle Management Conference (LCM 2009). Results - Conference focus: While the focus of the conference was LCM, LCA remains a main analytical tool for supporting LCM. This is clearly shown by the overall program in which roughly half of the contributions focused on or used LCA. Some products and resources and environmental themes were markedly represented in the presentation subjects. Conference participation: The 180 delegates included 40 South Africans, 20 from other African countries, and 140 from as far afield as Brazil, Sweden, Japan, and Australia. The surveyable number of delegates and conference rooms, in combination with the well-balanced scientific and social program, facilitated optimal professional exchange and discussion. Conference structure: LCM 2009 featured some 140 contributions from 47 leading environmental practitioners, consultants, and academic researchers. The interactive conference format included three plenary sessions and training workshops. Conclusions - LCM 2009 successfully engaged with the critical questions of what it means to manage (not merely shift) the environmental and social impacts of global economic activity, what this entails for industry and public services in emerging economies, and how supply chains, networks, and partnerships can be stimulated and managed to deliver truly sustainable practic
No-cloning theorem in thermofield dynamics
We discuss the relation between the no-cloning theorem from quantum
information and the doubling procedure used in the formalism of thermofield
dynamics (TFD). We also discuss how to apply the no-cloning theorem in the
context of thermofield states defined in TFD. Consequences associated to mixed
states, von Neumann entropy and thermofield vacuum are also addressed.Comment: 16 pages, 3 figure
Dynamics of bubbles in a two-component Bose-Einstein condensate
The dynamics of a phase-separated two-component Bose-Einstein condensate are
investigated, in which a bubble of one component moves through the other
component. Numerical simulations of the Gross--Pitaevskii equation reveal a
variety of dynamics associated with the creation of quantized vortices. In two
dimensions, a circular bubble deforms into an ellipse and splits into fragments
with vortices, which undergo the Magnus effect. The B\'enard--von K\'arm\'an
vortex street is also generated. In three dimensions, a spherical bubble
deforms into toruses with vortex rings. When two rings are formed, they exhibit
leapfrogging dynamics.Comment: 6 pages, 7 figure
Identities in the Superintegrable Chiral Potts Model
We present proofs for a number of identities that are needed to study the
superintegrable chiral Potts model in the sector.Comment: LaTeX 2E document, using iopart.cls with iopams packages. 11 pages,
uses eufb10 and eurm10 fonts. Typeset twice! vs2: Two equations added. vs3:
Introduction adde
General U(N) gauge transformations in the realm of covariant Hamiltonian field theory
A consistent, local coordinate formulation of covariant Hamiltonian field
theory is presented. While the covariant canonical field equations are
equivalent to the Euler-Lagrange field equations, the covariant canonical
transformation theory offers more general means for defining mappings that
preserve the action functional - and hence the form of the field equations -
than the usual Lagrangian description. Similar to the well-known canonical
transformation theory of point dynamics, the canonical transformation rules for
fields are derived from generating functions. As an interesting example, we
work out the generating function of type F_2 of a general local U(N) gauge
transformation and thus derive the most general form of a Hamiltonian density
that is form-invariant under local U(N) gauge transformations.Comment: 36 pages, Symposium on Exciting Physics: Quarks and gluons/atomic
nuclei/biological systems/networks, Makutsi Safari Farm, South Africa, 13-20
November 2011; Exciting Interdisciplinary Physics, Walter Greiner, Ed., FIAS
Interdisciplinary Science Series, Springer International Publishing
Switzerland, 201
Enhanced energy relaxation process of quantum memory coupled with a superconducting qubit
For quantum information processing, each physical system has different
advantage for the implementation and so hybrid systems to benefit from several
systems would be able to provide a promising approach. One of the common hybrid
approach is to combine a superconducting qubit as a controllable qubit and the
other quantum system with a long coherence time as a memory qubit. The
superconducting qubit allows us to have an excellent controllability of the
quantum states and the memory qubit is capable of storing the information for a
long time. By tuning the energy splitting between the superconducting qubit and
the memory qubit, it is believed that one can realize a selective coupling
between them. However, we have shown that this approach has a fundamental
drawback concerning energy leakage from the memory qubit. The detuned
superconducting qubit is usually affected by severe decoherence, and this
causes an incoherent energy relaxation from the memory qubit to the
superconducting qubit via the imperfect decoupling. We have also found that
this energy transport can be interpreted as an appearance of anti quantum Zeno
effect induced by the fluctuation in the superconducting qubit. We also discuss
a possible solution to avoid such energy relaxation process, which is feasible
with existing technology
Dynamical creation of entanglement by homodyne-mediated feedback
For two two-level atoms coupled to a single-mode cavity field that is driven
and heavily damped, the steady-state can be entangled by shining an
un-modulated driving laser on the system [S.Schneider, G. J. Milburn Phys. Rev
A 65, 042107, 2002]. We present a scheme to significantly increase the
steady-state entanglement by using homodyne-mediated feedback, in which the
driving laser is modulated by the homodyne photocurrent derived from the cavity
output. Such feedback can increase the nonlinear response to both the
decoherence process of the two-qubit system and the coherent evolution of
individual qubits. We present the properties of the entangled states using the
SO(3) Q function.Comment: 8 page
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