Spin-orbit coupling and the conservation of angular momentum

In nonrelativistic quantum mechanics, the total (i.e. orbital plus spin) angular momentum of a charged particle with spin that moves in a Coulomb plus spin-orbit-coupling potential is conserved. In a classical nonrelativistic treatment of this problem, in which the Lagrange equations determine the orbital motion and the Thomas equation yields the rate of change of the spin, the particle's total angular momentum in which the orbital angular momentum is defined in terms of the kinetic momentum is generally not conserved. However, a generalized total angular momentum, in which the orbital part is defined in terms of the canonical momentum, is conserved. This illustrates the fact that the quantum-mechanical operator of momentum corresponds to the canonical momentum of classical mechanics.Comment: 10 pages, as published by Eur. J. Phy

Building the field of health policy and systems research: framing the questions.

In the first of a series of articles addressing the current challenges and opportunities for the development of Health Policy & Systems Research (HPSR), Kabir Sheikh and colleagues lay out the main questions vexing the field

Exploring the Feasibility of Service Integration in a Low-Income Setting: A Mixed Methods Investigation into Different Models of Reproductive Health and HIV Care in Swaziland.

Integrating reproductive health (RH) with HIV care is a policy priority in high HIV prevalence settings, despite doubts surrounding its feasibility and varying evidence of effects on health outcomes. The process and outcomes of integrated RH-HIV care were investigated in Swaziland, through a comparative case study of four service models, ranging from fully integrated to fully stand-alone HIV services, selected purposively within one town. A client exit survey (n=602) measured integrated care received and unmet family planning (FP) needs. Descriptive statistics were used to assess the degree of integration per clinic and client demand for services. Logistic regression modelling was used to test the hypothesis that clients at more integrated sites had lower unmet FP needs than clients in a stand-alone site. Qualitative methods included in-depth interviews with clients and providers to explore contextual factors influencing the feasibility of integrated RH-HIV care delivery; data were analysed thematically, combining deductive and inductive approaches. Results demonstrated that clinic models were not as integrated in practice as had been claimed. Fragmentation of HIV care was common. Services accessed per provider were no higher at the more integrated clinics compared to stand-alone models (p>0.05), despite reported demand. While women at more integrated sites received more FP and pregnancy counselling than stand-alone models, they received condoms (a method of choice) less often, and there was no statistical evidence of difference in unmet FP needs by model of care. Multiple contextual factors influenced integration practices, including provider de-skilling within sub-specialist roles; norms of task-oriented routinised HIV care; perceptions of heavy client loads; imbalanced client-provider interactions hindering articulation of RH needs; and provider motivation challenges. Thus, despite institutional support, factors related to the social context of care inhibited provision of fully integrated RH-HIV services in these clinics. Programmes should move beyond simplistic training and equipment provision if integrated care interventions are to be sustained

Time perception and the experience of agency in meditation and hypnosis

Mindfulness meditation and hypnosis are related in opposing ways to awareness of intentions. The cold control theory of hypnosis proposes that hypnotic responding involves the experience of involuntariness while performing an actually intentional action. Hypnosis therefore relies upon inaccurate metacognition about intentional actions and experiences. Mindfulness meditation centrally involves awareness of intentions and is associated with improved metacognitive access to intentions. Therefore, mindfulness meditators and highly hypnotizable people may lie at opposite ends of a spectrum with regard to metacognitive access to intention‐related information. Here we review the theoretical background and evidence for differences in the metacognition of intentions in these groups, as revealed by chronometric measures of the awareness of voluntary action: the timing of an intention to move (Libet's “W” judgments) and the compressed perception of time between an intentional action and its outcome (“intentional binding”). We review these measures and critically evaluate their proposed connection to the experience of volition and sense of agency

Lady Gaga as (dis)simulacrum of monstrosity

Lady Gaga’s celebrity DNA revolves around the notion of monstrosity, an extensively researched concept in postmodern cultural studies. The analysis that is offered in this paper is largely informed by Deleuze and Guattari’s notion of monstrosity, as well as by their approach to the study of sign-systems that was deployed in A Thousand Plateaus. By drawing on biographical and archival visual data, with a focus on the relatively underexplored live show, an elucidation is afforded of what is really monstrous about Lady Gaga. The main argument put forward is that monstrosity as sign seeks to appropriate the horizon of unlimited semiosis as radical alterity and openness to signifying possibilities. In this context it is held that Gaga effectively delimits her unique semioscape; however, any claims to monstrosity are undercut by the inherent limits of a representationalist approach in sufficiently engulfing this concept. Gaga is monstrous for her community insofar as she demands of her fans to project their semiosic horizon onto her as a simulacrum of infinite semiosis. However, this simulacrum may only be evinced in a feigned manner as a (dis)simulacrum. The analysis of imagery from seminal live shows during 2011–2012 shows that Gaga’s presumed monstrosity is more akin to hyperdifferentiation as simultaneous employment of heterogeneous and potentially dissonant inter pares cultural representations. The article concludes with a problematisation of audience effects in the light of Gaga’s adoption of a schematic and post-representationalist strategy in the event of her strategy’s emulation by competitive artists

Effects of Fluids on the Macro- and Microcirculations.

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2018. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2018. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901

PHIP - a novel candidate breast cancer susceptibility locus on 6q14.1

Most non-BRCA1/2 breast cancer families have no identified genetic cause. We used linkage and haplotype analyses in familial and sporadic breast cancer cases to identify a susceptibility locus on chromosome 6q. Two independent genome-wide linkage analysis studies suggested a 3 Mb locus on chromosome 6q and two unrelated Swedish families with a LOD > 2 together seemed to share a haplotype in 6q14.1. We hypothesized that this region harbored a rare high-risk founder allele contributing to breast cancer in these two families. Sequencing of DNA and RNA from the two families did not detect any pathogenic mutations. Finally, 29 SNPs in the region were analyzed in 44,214 cases and 43,532 controls from BCAC, and the original haplotypes in the two families were suggested as low-risk alleles for European and Swedish women specifically. There was also some support for one additional independent moderate-risk allele in Swedish familial samples. The results were consistent with our previous findings in familial breast cancer and supported a breast cancer susceptibility locus at 6q14.1 around the PHIP gene.Peer reviewe

Microsecond Lifetimes and Low Interface Recombination Velocities in Moderately Doped n-GaAs Thin Films

We have observed lifetimes greater than 1 ps in moderately doped, thin film, n-GaAs/A1a,Gae,As double heterostructure membranes formed by etching away the substrate. We attribute these ultralong lifetimes to enhanced photon recycling caused by the removal of the substrate. Nonradiative recombination in the bulk and at the interfaces is very low; the upper limit of the interface recombination velocity is 25 cm/S.-Such long lifetimes in GaAs doped at N,= 1.3 X 10” cme3 suggest that thin-film solar cells offer a potential option for achieving very high efficiencies

Effects of dyslexia on postural control in adults

This is an accepted manuscript of an article published by Wiley in Dyslexia on 01/02/2010, available online: https://doi.org/10.1002/dys.398 The accepted version of the publication may differ from the final published version.Dyslexia has been shown to affect postural control. The aim of the present study was to investigate the difference in postural stability measured as torque variance in an adult dyslexic group (n =14, determined using the Adult Dyslexia Checklist (ADCL) and nonsense word repetition test) and an adult non‐dyslexic group (n =39) on a firm surface and on a foam block and with eyes open and eyes closed. Another aim was to investigate the correlation between ADCL scores and postural stability. Findings showed that ADCL scores correlated with torque variance in the anteroposterior direction on foam with eyes closed (p =0.001) and in the lateral direction on the foam surface with eyes closed (p =0.040) and open (p =0.010). General Linear Model analysis showed that high dyslexia scores were associated with increased torque variance (p <0.001). However, we found no significant difference between dyslexics and non‐dyslexics, though there were indications of larger torque variance in the dyslexics. The findings suggest that adults with high dyslexic ADCL scores may experience sub‐clinical balance deficits. Hence, assessing motor ability and postural control in those with high ADCL scores is motivated. Copyright © 2010 John Wiley & Sons, Ltd.Published versio

Carrier thermalization dynamics in single zincblende and wurtzite InP nanowires

Using transient Rayleigh scattering (TRS) measurements, we obtain photoexcited carrier thermalization dynamics for both zincblende (ZB) and wurtzite (WZ) InP single nanowires (NW) with picosecond resolution. A phenomenological fitting model based on direct band-to-band transition theory is developed to extract the electron-hole–plasma density and temperature as a function of time from TRS measurements of single nanowires, which have complex valence band structures. We find that the thermalization dynamics of hot carriers depends strongly on material (GaAs NW vs InP NW) and less strongly on crystal structure (ZB vs WZ). The thermalization dynamics of ZB and WZ InP NWs are similar. But a comparison of the thermalization dynamics in ZB and WZ InP NWs with ZB GaAs NWs reveals more than an order of magnitude slower relaxation for the InP NWs. We interpret these results as reflecting their distinctive phonon band structures that lead to different hot phonon effects. Knowledge of hot carrier thermalization dynamics is an essential component for effective incorporation of nanowire materials into electronic devices