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

Effect of alcohol on the sense of agency in healthy humans

Even at low to moderate doses, ingestion of the widely used recreational drug alcohol (ethanol) can impact cognitive and emotional processing. Recent studies show that the sense of agency (SoA; ie, the subjective experience of voluntary control over actions) can be modulated by specific pharmacological manipulations. The SoA, as quantified by the intentional binding (IB) paradigm, is enhanced by direct or indirect dopaminergic agonists in patients with Parkinson's disease and by ketamine (an N‐methyl‐D‐aspartate (NMDA) receptor antagonist) in healthy individuals. These findings implicate dopaminergic and glutamatergic neurotransmission in mechanisms underlying SoA. Alcohol has a complex set of actions, including disinhibition of dopaminergic neurotransmission and allosteric antagonism at NMDA receptors. Here, we tested the hypothesis that low to moderate doses of alcohol would enhance SoA, and impact impulsivity and subjective emotional state. We conducted two experiments in 59 healthy male and female social drinkers, who ingested either a placebo “vehicle,” or one of two doses of ethanol: 0.4 and 0.6 g/kg. In both experiments, we observed increased SoA/IB at both doses of alcohol exposure, relative to the placebo condition. We found no correlation between the effects of alcohol on IB and on impulsivity or subjective emotional state. Our findings might have implications for social and legal responsibility related to alcohol use, particularly in states prior to overt intoxication. Further studies are necessary to investigate the effects of alcohol and other addictive substances on the SoA

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

A study of minority carrier lifetime versus doping concentration in n‐type GaAs grown by metalorganic chemical vapor deposition

Time‐resolved photoluminescence decay measurements are used to explore minority carrier recombination in n‐type GaAs grown by metalorganic chemical vapor deposition, and doped with selenium to produce electron concentrations from 1.3×1017 cm−3 to 3.8×1018 cm−3. For electron densities n0\u3c1018 cm−3, the lifetime is found to be controlled by radiative recombination and photon recycling with no evidence of Shockley–Read–Hall recombination. For higher electron densities, samples show evidence of Shockley–Read–Hall recombination as reflected in the intensity dependence of the photoluminescence decay. Still, we find that radiative recombination and photon recycling are important for all electron concentrations studied, and no evidence for Auger recombination was observed

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

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

The Iowa Homemaker vol.23, no.14

Winter in Iowa, page 2 Keeping Up With Today, Mary Elizabeth Lush, page 2 Presenting Martha Duncan, D. Jean Merrill, page 3 Students Create Furniture, Marjorie Lund, page 4 Describe Food in South Pacific, Gertrud Ortgies, page 5 Vicky Previews a New Year, Josephine Ahern, page 6 Teaches Homemaking in India, Mrs. Edgar Vestal, page 7 What’s New in Home Economics, Marilyn Mitchell, page 8 Thoughtful Reading, Jo Ann Reeves, page 10 Across Alumnae Desks, Harriet Keen, page 12 Alum Chooses Food Publicity, Rowena Lincoln, page 14 Betty Heileman Feeds Trainees, Ann Turner, page 1

The Iowa Homemaker vol.23, no.15

Keeping Up With Today, D. Jean Merrill, page 2 Institution Recipes Are Acclaimed, Victoria McKibben, page 3 Democracy Begins in the Home, Jean Larson, page 4 Schools Sponsor Nutrition Program, Jean Bunge, page 5 Vicky Rehearses for Spring, Josephine Ahern, page 6 What’s New in Home Economics, Marilyn Mitchell, page 8 Benefit from College Placement, Mary Elva Sather, page 10 Well-known Cooks Open Their Kitchens, Mary E. Lush, page 11 Alums in the News, Patricia Maddex, page 12 Distinguished Alumnus Credits Home, Marjorie Shuler, page 14 Across Alumnae Desks, Harriet Keen, page 15 Women’s Follies in Fashion, Lila Mae Hummel, page 1

Degeneracija aksona i esteraza povezana s neuropatskim djelovanjem organofosfornih spojeva - pregled

This brief review summarises recent observations which suggest a possible mechanism for organophosphateinduced delayed neuropathy (OPIDN). Neuropathy target esterase (NTE) has been shown to deacylate endoplasmic reticulum (ER) membrane phosphatidylcholine (PtdCho). Raised levels of PtdCho are present in the brains of swiss cheese/NTE mutant Drosophila together with abnormal membrane structures, axonal and dendritic degeneration and neural cell loss. Similar vacuolated pathology is found in the brains of mice with brain-specific deletion of the NTE gene and, in old age, these mice show clinical and histopathological features of neuropathy resembling those in wild-type mice chronically dosed with tri-ortho-cresylphosphate. It is suggested that OPIDN results from the loss of NTE’s phospholipase activity which in turn causes ER malfunction and perturbation of axonal transport and glial-axonal interactions.Ovim se kratkim pregledom razmatraju nedavna opažanja koja upućuju na mogući mehanizam odgođene neuropatije uzrokovane organofosfatima (engl. organophosphate-induced delayed neuropathy, krat. OPIDN). Za esterazu povezanu s neuropatskim djelovanjem organofosfornih spojeva (engl. neuropathy target esterase, krat. NTE) dokazano je da deacilira fosfatidilkolin (PtdCho) membrane endoplazmatskog retikuluma (ER). Povišene razine PtdCho prisutne su u mozgu swiss cheese/NTE mutanta mušice Drosophila uz abnormalne membranske strukture, degeneraciju aksona i dendrita te gubitak neurona. Slična je vakuolarna patologija zamijećena u mozgu miševa u kojih je obrisan NTE gen u mozgu te koji u starijoj dobi pokazuju kliničke i histopatološke znakove neuropatije koja je slična onoj u običnih miševa kronično tretiranih tri-ortho-krezilfosfatom. Odgođena neuropatija uzrokovana organofosfatima mogla bi biti posljedicom prestanka djelovanja fosfolipaze NTE, što potom uzrokuje zatajenje endoplazmatskog retikuluma i smetnje u prijenosu signala putem aksona te interakcije između glija i aksona