Why stigma matters in addressing alcohol harm

Alcohol problems are amongst the most stigmatized of conditions, resulting in multiple additional harms for people with Alcohol Use Disorder (AUD). Alcohol stigma encompasses widely endorsed negative stereotypes leading to prejudice and discrimination towards people with AUD. Self-stigma further harms individuals through preventing and undermining recovery. The persistence of alcohol stigma highlights the limitations of an illness model of AUD for stigma reduction; in fact, many groups inadvertently reinforce stigma by emphasizing the artificial line between ‘normal’ drinkers and the pathologized ‘alcoholic other’. A public health case for alcohol stigma reduction highlights the need to address this societal false dichotomization of problem drinkers. Promoting a continuum aligned model of AUD, a dynamic model of responsibility, and other evidence-led approaches such as person-first language by key stakeholders are recommended

Can 'justified disapproval' be separated from addiction stigma? An empirical focus is required

Stigma is largely recognized as a harmful practice of social devaluation and discrimination, yet some scholars still advance arguments that stigma also serves an important disincentivizing force towards addictive behaviours. Whilst others counter that stigma is a fundamentally harmful process, a more nuanced call has been made for “justified disapproval” as a beneficial normative force to be separated from addiction stigma. The legitimacy of such a claim requires empirical support which has been lacking thus far. We review evidence in the domains of social norms, stigma, addiction and behavioural sciences as a starting point for an empirically focused evaluation of the possibility of “justified disapproval” as a legitimate positive force. We note that whilst normative influences, emotions and addiction-relevant appraisals affect such behaviours under certain conditions, there are important questions regarding whether these can be harnessed without invoking the known and pervasive effects of stigma. Rather, we propose that efforts to curb addiction-related behaviours via normative influences are likely to fail or backfire. In the absence of empirical evidence to support the use of normative ‘disapproval’ strategies, alternative approaches should be pursued, particularly those which address the broader socio-cultural and structural drivers of addiction problems

Wilson lines on noncommutative tori

We introduce the notion of a monodromy for gauge fields with vanishing curvature on the noncommutative torus. Similar to the ordinary gauge theory, traces of the monodromies define noncommutative Wilson lines. Our main result is that these Wilson lines are invariant under the Seiberg-Witten map changing the deformation parameter of the noncommutative torus.Comment: 4 pages, LaTeX (revtex), it is explained why the costruction of a Wilson line using the path ordered exponent does not apply in the noncommutative cas

Uniform approximations for non-generic bifurcation scenatios including bifurcations of ghost orbits

Gutzwiller's trace formula allows interpreting the density of states of a classically chaotic quantum system in terms of classical periodic orbits. It diverges when periodic orbits undergo bifurcations, and must be replaced with a uniform approximation in the vicinity of the bifurcations. As a characteristic feature, these approximations require the inclusion of complex ``ghost orbits''. By studying an example taken from the Diamagnetic Kepler Problem, viz. the period-quadrupling of the balloon-orbit, we demonstrate that these ghost orbits themselves can undergo bifurcations, giving rise to non-generic complicated bifurcation scenarios. We extend classical normal form theory so as to yield analytic descriptions of both bifurcations of real orbits and ghost orbit bifurcations. We then show how the normal form serves to obtain a uniform approximation taking the ghost orbit bifurcation into account. We find that the ghost bifurcation produces signatures in the semiclassical spectrum in much the same way as a bifurcation of real orbits does.Comment: 56 pages, 21 figure, LaTeX2e using amsmath, amssymb, epsfig, and rotating packages. To be published in Annals of Physic

Disorder-induced pseudodiffusive transport in graphene nanoribbons.

We study the transition from ballistic to diffusive and localized transport in graphene nanoribbons in the presence of binary disorder, which can be generated by chemical adsorbates or substitutional doping. We show that the interplay between the induced average doping (arising from the nonzero average of the disorder) and impurity scattering modifies the traditional picture of phase-coherent transport. Close to the Dirac point, intrinsic evanescent modes produced by the impurities dominate transport at short lengths giving rise to a regime analogous to pseudodiffusive transport in clean graphene, but without the requirement of heavily doped contacts. This intrinsic pseudodiffusive regime precedes the traditional ballistic, diffusive, and localized regimes. The last two regimes exhibit a strongly modified effective number of propagating modes and a mean free path which becomes anomalously large close to the Dirac point

Significance of Ghost Orbit Bifurcations in Semiclassical Spectra

Gutzwiller's trace formula for the semiclassical density of states in a chaotic system diverges near bifurcations of periodic orbits, where it must be replaced with uniform approximations. It is well known that, when applying these approximations, complex predecessors of orbits created in the bifurcation ("ghost orbits") can produce pronounced signatures in the semiclassical spectra in the vicinity of the bifurcation. It is the purpose of this paper to demonstrate that these ghost orbits themselves can undergo bifurcations, resulting in complex, nongeneric bifurcation scenarios. We do so by studying an example taken from the Diamagnetic Kepler Problem, viz. the period quadrupling of the balloon orbit. By application of normal form theory we construct an analytic description of the complete bifurcation scenario, which is then used to calculate the pertinent uniform approximation. The ghost orbit bifurcation turns out to produce signatures in the semiclassical spectrum in much the same way as a bifurcation of real orbits would.Comment: 20 pages, 6 figures, LATEX (IOP style), submitted to J. Phys.

D-branes with Lorentzian signature in the Nappi-Witten model

Lorentzian signature D-branes of all dimensions for the Nappi-Witten string are constructed. This is done by rewriting the gluing condition $J_+=FJ_-$ for the model chiral currents on the brane as a well posed first order differential problem and by solving it for Lie algebra isometries $F$ other than Lie algebra automorphisms. By construction, these D-branes are not twined conjugacy classes. Metrically degenerate D-branes are also obtained.Comment: 22 page

Classical orbit bifurcation and quantum interference in mesoscopic magnetoconductance

We study the magnetoconductance of electrons through a mesoscopic channel with antidots. Through quantum interference effects, the conductance maxima as functions of the magnetic field strength and the antidot radius (regulated by the applied gate voltage) exhibit characteristic dislocations that have been observed experimentally. Using the semiclassical periodic orbit theory, we relate these dislocations directly to bifurcations of the leading classes of periodic orbits.Comment: 4 pages, including 5 figures. Revised version with clarified discussion and minor editorial change