1,597 research outputs found
Avalanche boron fusion by laser picosecond block ignition with magnetic trapping for clean and economic reactor
After the very long consideration of the ideal energy source by fusion of the
protons of light hydrogen with the boron isotope 11 (boron fusion HB11) the
very first two independent measurements of very high reaction gains by lasers
basically opens a fundamental breakthrough. The non-thermal plasma block
ignition with extremely high power laser pulses above petawatt of picosecond
duration in combination with up to ten kilotesla magnetic fields for trapping
has to be combined to use the measured high gains as proof of an avalanche
reaction for an environmentally clean, low cost and lasting energy source as
potential option against global warming. The unique HB11 avalanche reaction is
are now based on elastic collisions of helium nuclei (alpha particles) limited
only to a reactor for controlled fusion energy during a very short time within
a very small volume.Comment: 11 pages, 6 figures, Submitted to Proceedings 2nd Symposium High
Power Laser Science and Engineering, 14-18 MARCH 2016, Suzhou/Chin
Impact of spin-orbit coupling on quantum Hall nematic phases
Anisotropic charge transport is observed in a two-dimensional (2D) hole
system in a perpendicular magnetic field at filling factors nu=7/2, nu=11/2,
and nu=13/2 at low temperature. In stark contrast, the transport at nu=9/2 is
isotropic for all temperatures. Isotropic hole transport at nu=7/2 is restored
for sufficiently low 2D densities or an asymmetric confining potential. The
density and symmetry dependences of the observed anisotropies suggest that
strong spin-orbit coupling in the hole system contributes to the unusual
transport behavior.Comment: 4 pages, 4 figure
Taxing the powerful, the rise of populism and the crisis in Europe: the case for the EU Common Consolidated Corporate Tax Base
Contemporary populism is rooted in a crisis of legitimacy. Corporate taxavoidance by multinationals is one cause of that crisi s. Although states tend to beincreasingly formally committed to tackling avoidance, they do so in a system thatpromotes contradictory sets of behaviour. This tends to undermine attempts to solvethe problem of avoidance unless a more transformative collective approach is taken.Ironically, despite its own democratic deficit, the European Comm ission has taken aleading role in promoting such a solution: the Common Consolidated Corporate TaxBase (CCCTB). In this paper, I set out the case for ‘unitary taxation’ based on theCCCTB and state some of its current problems. The problem of corporation taxraises a basic issue in terms of who is sovereignty for, and solving the problemprovides an important contribution to legitimacy of both the state and the EU
Transport in quantum wires
With a brief introduction to one-dimensional channels and conductance
quantisation in mesoscopic systems, we discuss some recent experimental puzzles
in these systems, which include reduction of quantised conductances and an
interesting {\it odd-even} effect in the presence of an in-plane magnetic
field. We then discuss a recent non-homogeneous Luttinger liquid model proposed
by us, which addresses and gives an explanation for the reduced conductances
and the {\it odd-even} effect. We end with a brief summary and discussion of
future projects.Comment: Talk presented at the International Discussion Meeting on Mesoscopic
and Disordered systems, December, 2000, 16 pages, 2 figure
Invited review Molecules and circuits involved in nicotine addiction: The many faces of smoking
a b s t r a c t Tobacco smoking in humans is one of the most persistent and widespread addictions and is driven by nicotine in tobacco smoke. Over the last several decades, understanding of the molecular and cellular basis for nicotine addiction has increased tremendously as a result of pharmacological, molecular genetic, electrophysiological and behavioral studies of nicotine reinforcement. Studies of the biological basis for nicotine reinforcement has helped in the design of new treatments for smoking cessation such as varenicline; however, smokers report that they smoke for many reasons, including the ability to control symptoms of anxiety and depression or the desire to control appetite. Further, developmental exposure to tobacco smoke increases the likelihood of adult smoking. Here we review what is known about the molecular and circuit basis for a number of behaviors related to tobacco smoking. Leveraging the knowledge from studies of different behaviors mediated by nicotine receptors in multiple brain circuits could provide points of convergence that will inform future therapeutic development for smoking cessation. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'
Chronic arsenic exposure and risk of infant mortality in two areas of Chile.
Chronic arsenic exposure has been associated with a range of neurologic, vascular, dermatologic, and carcinogenic effects. However, limited research has been directed at the association of arsenic exposure and human reproductive health outcomes. The principal aim of this study was to investigate the trends in infant mortality between two geographic locations in Chile: Antofagasta, which has a well-documented history of arsenic exposure from naturally contaminated water, and Valparaíso, a comparable low-exposure city. The arsenic concentration in Antofagasta's public drinking water supply rose substantially in 1958 with the introduction of a new water source, and remained elevated until 1970. We used a retrospective study design to examine time and location patterns in infant mortality between 1950 and 1996, using univariate statistics, graphical techniques, and Poisson regression analysis. Results of the study document the general declines in late fetal and infant mortality over the study period in both locations. The data also indicate an elevation of the late fetal, neonatal, and postneonatal mortality rates for Antofagasta, relative to Valparaíso, for specific time periods, which generally coincide with the period of highest arsenic concentration in the drinking water of Antofagasta. Poisson regression analysis yielded an elevated and significant association between arsenic exposure and late fetal mortality [rate ratio (RR) = 1.7; 95% confidence interval (CI), 1.5-1.9], neonatal mortality (RR = 1.53; CI, 1.4-1.7), and postneonatal mortality (RR = 1.26; CI, 1.2-1.3) after adjustment for location and calendar time. The findings from this investigation may support a role for arsenic exposure in increasing the risk of late fetal and infant mortality
K+ to pi-mu+mu+ and doubly-charged Higgs
The rate for the lepton-number-violating decay K+ to pi- mu+mu+ is calculated
in a model which incorporates doubly-charged Higgs bosons. We find that for
reasonable values of the parameters the decay branching ratio may be as large
as 2E-16. Although this is a discouragingly small number, it is of the same
order of magnitude as the rate mediated by massive Majorana neutrinos.Comment: 8 pages, RevTex, Figure1 is P
Landauer formula without Landauer's assumptions
The Landauer formula for dissipationless conductance lies at the heart of
modern electronic transport, yet it remains without a clear microscopic basis.
We analyze the Landauer formula microscopically, and give a straightforward
quantum kinetic derivation for open systems. Some important experimental
implications follow. These lie beyond the Landauer result as popularly
received.Comment: LaTeX, 7pp, one fi
Observation of a One-Dimensional Spin-Orbit Gap in a Quantum Wire
Understanding the flow of spins in magnetic layered structures has enabled an
increase in data storage density in hard drives over the past decade of more
than two orders of magnitude1. Following this remarkable success, the field of
'spintronics' or spin-based electronics is moving beyond effects based on local
spin polarisation and is turning its attention to spin-orbit interaction (SOI)
effects, which hold promise for the production, detection and manipulation of
spin currents, allowing coherent transmission of information within a device.
While SOI-induced spin transport effects have been observed in two- and
three-dimensional samples, these have been subtle and elusive, often detected
only indirectly in electrical transport or else with more sophisticated
techniques. Here we present the first observation of a predicted 'spin-orbit
gap' in a one-dimensional sample, where counter-propagating spins, constituting
a spin current, are accompanied by a clear signal in the easily-measured linear
conductance of the system.Comment: 10 pages, 5 figures, supplementary informatio
Predictors of Hepatitis B Surface Antigen Titers two decades after vaccination in a cohort of students and post-graduates of the Medical School at the University of Palermo, Italy
Introduction and objective. The introduction of a vaccine against hepatitis B virus (HBV) for newborn babies in Italy in 1991, extended to 12-year-old children for the first 12 years of application, has been a major achievement in terms of the
prevention of HBV infection. The objective of this study was to analyse the long-term immunogenicity and effectiveness of HBV vaccination among healthcare students with different working seniorities.
Materials and method. A cross-sectional observational study of undergraduate and postgraduate students attending the Medical School of the University of Palermo was conducted from January 2014 \u2013 July 2016. HBV serum markers were performed with commercial chemiluminescence assays. Categorical variables were analyzed using the chi-square test (Mantel\u2013Haenszel), whereas means were compared by using the Student\u2019s t test. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were also calculated by a multivariable logistic regression, using a model constructed to examine predictors of anti-HBs titer above 10 mIU/mL, assumed as protective.
Results. Of the 2,114 subjects evaluated \u2013 all vaccinated at infancy or at the age of 12 years and were HBsAg/anti-HBc negative \u2013 806 (38.1%) had an anti-HBs titre <10 IU/L. The latter were younger, more likely to be attending a healthcare
profession school (i.e., nursing and midwifery), than a medical postgraduate level school, and more likely to have been vaccinated in infancy (p <0.001, 95% CI 2.63\u20135.26, adjusted OR 3.70).
Conclusion. The results of the study suggest that assessment of HBV serum markers in workers potentially exposed to hospital infections is useful for identifying small numbers of unvaccinated subjects, or vaccinated subjects with low antibody titre, all of whom should be referred to a booster series of vaccinations
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