40 research outputs found
Slowly Rotating General Relativistic Superfluid Neutron Stars with Relativistic Entrainment
Neutron stars that are cold enough should have two or more
superfluids/supercondutors in their inner crusts and cores. The implication of
superfluidity/superconductivity for equilibrium and dynamical neutron star
states is that each individual particle species that forms a condensate must
have its own, independent number density current and equation of motion that
determines that current. An important consequence of the quasiparticle nature
of each condensate is the so-called entrainment effect, i.e. the momentum of a
condensate is a linear combination of its own current and those of the other
condensates. We present here the first fully relativistic modelling of slowly
rotating superfluid neutron stars with entrainment that is accurate to the
second-order in the rotation rates. The stars consist of superfluid neutrons,
superconducting protons, and a highly degenerate, relativistic gas of
electrons. We use a relativistic - mean field model for the
equation of state of the matter and the entrainment. We determine the effect of
a relative rotation between the neutrons and protons on a star's total mass,
shape, and Kepler, mass-shedding limit.Comment: 30 pages, 10 figures, uses ReVTeX
Magnetic Field Generation in Stars
Enormous progress has been made on observing stellar magnetism in stars from
the main sequence through to compact objects. Recent data have thrown into
sharper relief the vexed question of the origin of stellar magnetic fields,
which remains one of the main unanswered questions in astrophysics. In this
chapter we review recent work in this area of research. In particular, we look
at the fossil field hypothesis which links magnetism in compact stars to
magnetism in main sequence and pre-main sequence stars and we consider why its
feasibility has now been questioned particularly in the context of highly
magnetic white dwarfs. We also review the fossil versus dynamo debate in the
context of neutron stars and the roles played by key physical processes such as
buoyancy, helicity, and superfluid turbulence,in the generation and stability
of neutron star fields.
Independent information on the internal magnetic field of neutron stars will
come from future gravitational wave detections. Thus we maybe at the dawn of a
new era of exciting discoveries in compact star magnetism driven by the opening
of a new, non-electromagnetic observational window.
We also review recent advances in the theory and computation of
magnetohydrodynamic turbulence as it applies to stellar magnetism and dynamo
theory. These advances offer insight into the action of stellar dynamos as well
as processes whichcontrol the diffusive magnetic flux transport in stars.Comment: 41 pages, 7 figures. Invited review chapter on on magnetic field
generation in stars to appear in Space Science Reviews, Springe
'Education, education, education' : legal, moral and clinical
This article brings together Professor Donald Nicolson's intellectual interest in professional legal ethics and his long-standing involvement with law clinics both as an advisor at the University of Cape Town and Director of the University of Bristol Law Clinic and the University of Strathclyde Law Clinic. In this article he looks at how legal education may help start this process of character development, arguing that the best means is through student involvement in voluntary law clinics. And here he builds upon his recent article which argues for voluntary, community service oriented law clinics over those which emphasise the education of students
Search for patterns by combining cosmic-ray energy and arrival directions at the Pierre Auger Observatory
Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with E > = 6×1019 eV by analyzing cosmic rays with energies above E > = 5×1018 eV arriving within an angular separation of approximately 15°. We characterize the energy distributions inside these regions by two independent methods, one searching for angular dependence of energy-energy correlations and one searching for collimation of energy along the local system of principal axes of the energy distribution. No significant patterns are found with this analysis. The comparison of these measurements with astrophysical scenarios can therefore be used to obtain constraints on related model parameters such as strength of cosmic-ray deflection and density of point sources
An Extraterritorial FDA: Could the Food and Drug Administration Apply Its Informed Consent Requirement Abroad Consistent with International Law?
This paper addresses the regulatory challenges wrought by the increasing amount of human subject drug testing conducted in developing countries in support of new drug applications to the Food and Drug Administration. Specifically, it examines the difficulty of enforcing the “informed consent” requirement for ethical scientific research performed in foreign territory. In poorer regions, a lack of government oversight, lower regulatory standards, and barriers to communication have too frequently resulted in allegations of human experimentation performed without its participants’ informed consent. In order to solve this problem, some commentators have suggested that the FDA could apply its human subject protections to foreign clinical research, and enforce them through injunctions or criminal prosecutions. However, the international legal limits on states’ prescriptive jurisdiction may prohibit this exercise of extraterritoriality. After analyzing the proposed extraterritorial regulation of foreign drug testing under the traditional bases and limitations of prescriptive jurisdiction, this paper concludes that such regulation would likely violate international law. However, because nonconsensual clinical research has previously been regarded as a crime against humanity, the FDA might be able to bring criminal prosecutions under the principal of “universal jurisdiction” against investigators or sponsors who conducted studies without their subjects’ informed consent. This analysis offers both positive and normative conclusions regarding the international legal system and the human rights regime
Adolescent body mass index is decreased in children conceived by infertile couples, regardless of fertility treatment
Does outcome of the first IVF cycle allow selection of candidates for repeat IVF prior to PGS?
Should ICSI be the treatment of choice if male partners present with increased sperm DNA damage?
Domestic vs. International Spillovers: Evidence from Swedish Firm Level Data
This paper investigates the association between total factor productivity growth and the R&D expenditures of Swedish manufacturing firms in the presence of domestic- and international R&D spillovers. The paper assumes that the principal channel of transmission of new technology is through I/O relations. Econometric evidence suggests that international as well as domestic inter-industry R&D spillovers are important determinants of firms’ productivity growth in the long run. The R&D spillovers generated within the industry and following I/O links seem to be of minor importance in explaining productivity growth. It seems likely that within-industry productivity spillovers follow other channels than I/O flows, such as horizontal spillovers through copying of new products and processes, or labour turnover. The use of a convergence parameter is one way to check for such within-industry technology flows. Our results indicate that a catch-up process exists by which the non-frontier firms in the Swedish manufacturing sector absorb knowledge spillovers from the leading firms in the industry. Finally, a firm’s own R&D efforts are found to be more or less positively correlated with the TFP growth, maybe the contribution from R&D efforts in some sense are underestimated. Copyright Springer Science + Business Media, LLC 2006TFP growth, R&D expenditures, convergence, R&D spillovers, O31, O33,
