Information geometry in quantum field theory: lessons from simple examples

Motivated by the increasing connections between information theory and high-energy physics, particularly in the context of the AdS/CFT correspondence, we explore the information geometry associated to a variety of simple systems. By studying their Fisher metrics, we derive some general lessons that may have important implications for the application of information geometry in holography. We begin by demonstrating that the symmetries of the physical theory under study play a strong role in the resulting geometry, and that the appearance of an AdS metric is a relatively general feature. We then investigate what information the Fisher metric retains about the physics of the underlying theory by studying the geometry for both the classical 2d Ising model and the corresponding 1d free fermion theory, and find that the curvature diverges precisely at the phase transition on both sides. We discuss the differences that result from placing a metric on the space of theories vs. states, using the example of coherent free fermion states. We compare the latter to the metric on the space of coherent free boson states and show that in both cases the metric is determined by the symmetries of the corresponding density matrix. We also clarify some misconceptions in the literature pertaining to different notions of flatness associated to metric and non-metric connections, with implications for how one interprets the curvature of the geometry. Our results indicate that in general, caution is needed when connecting the AdS geometry arising from certain models with the AdS/CFT correspondence, and seek to provide a useful collection of guidelines for future progress in this exciting area.Comment: 36 pages, 2 figures; added new section and appendix, miscellaneous improvement

Showing Strength, Overcoming Silence: Improving the Mental Health of Men of Color

Examines the barriers faced by men of color in need of mental health care and highlights some promising approaches to provide models for larger scale state or federal reforms to improve their ability to seek and receive adequate care

Detection of viable Mycobacterium ulcerans in clinical samples by a novel combined 16S rRNA reverse transcriptase/IS2404 real-time qPCR assay.

Detection of Viable <em>Mycobacterium ulcerans</em> in Clinical Samples by a Novel Combined 16S rRNA Reverse Transcriptase/IS<em>2404</em> Real-Time qPCR Assa

Validity of the Contextual Competence Scale for Engineering Students

BackgroundEngineering educators and practitioners increasingly value contextual competence. A psychometrically sound, practical, and useful scale for assessing undergraduate engineering students' contextual competence is needed.Purpose/HypothesisThis article provides comprehensive evidence of the content, structural, discriminant, and criterion‐related validity of the contextual competence scale.Design/MethodThis study used student, alumni, and faculty survey data from a nationally representative sample of 120 U.S. engineering programs from 31 four‐year institutions. Validity evidence was obtained by expert review of questions, a pilot test, factor analyses, and several analyses utilizing t‐tests, correlations, and regression.ResultsExperts constructed the questions used in the scale (content validity). Those questions combined to measure a single concept (structural validity), the scale reliably measures (Cronbach's alpha = .91) that concept, and it focuses on contextual competence instead of other student outcomes (discriminant validity). The contextual competence scale varies according to students' characteristics and curricular experiences as well as similarities and differences in student and alumni levels of contextual competence in the same programs and institutions (criterion‐related validity). Finally, the scale may be a more accurate measure of contextual competence than faculty members' perceptions of students' ability.ConclusionsThe contextual competence scale allows engineering programs to meet ABET and other self‐study requirements or do large‐scale research with relative ease and little expense. The process described in this article can be used by other researchers in engineering education for their scale development efforts.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110541/1/jee20062.pd

Motor control drives visual bodily judgements

The ‘embodied cognition’ framework proposes that our motor repertoire shapes visual perception and cognition. But recent studies showing normal visual body representation in individuals born without hands challenges the contribution of motor control on visual body representation. Here, we studied hand laterality judgements in three groups with fundamentally different visual and motor hand experiences: two-handed controls, one-handers born without a hand (congenital one-handers) and one-handers with an acquired amputation (amputees). Congenital one-handers, lacking both motor and first-person visual information of their missing hand, diverged in their performance from the other groups, exhibiting more errors for their intact hand and slower reaction-times for challenging hand postures. Amputees, who have lingering non-visual motor control of their missing (phantom) hand, performed the task similarly to controls. Amputees’ reaction-times for visual laterality judgements correlated positively with their phantom hand’s motor control, such that deteriorated motor control associated with slower visual laterality judgements. Finally, we have implemented a computational simulation to describe how a mechanism that utilises a single hand representation in congenital one-handers as opposed to two in controls, could replicate our empirical results. Together, our findings demonstrate that motor control is a driver in making visual bodily judgments

A Profile of Pornography Users in Australia: Findings From the Second Australian Study of Health and Relationships

Copyright © The Society for the Scientific Study of Sexuality. There are societal concerns that looking at pornography has adverse consequences among those exposed. However, looking at sexually explicit material could have educative and relationship benefits. This article identifies factors associated with looking at pornography ever or within the past 12 months for men and women in Australia, and the extent to which reporting an “addiction” to pornography is associated with reported bad effects. Data from the Second Australian Study of Health and Relationships (ASHR2) were used: computer-assisted telephone interviews (CASIs) completed by a representative sample of 9,963 men and 10,131 women aged 16 to 69 years from all Australian states and territories, with an overall participation rate of 66%. Most men (84%) and half of the women (54%) had ever looked at pornographic material. Three-quarters of these men (76%) and more than one-third of these women (41%) had looked at pornographic material in the past year. Very few respondents reported that they were addicted to pornography (men 4%, women 1%), and of those who said they were addicted about half also reported that using pornography had had a bad effect on them. Looking at pornographic material appears to be reasonably common in Australia, with adverse effects reported by a small minority

Elevated arousal at time of decision-making is not the arbiter of risk avoidance in chickens

The somatic marker hypothesis proposes that humans recall previously experienced physiological responses to aid decision-making under uncertainty. However, little is known about the mechanisms used by non-human animals to integrate risk perception with predicted gains and losses. We monitored the behaviour and physiology of chickens when the choice between a high-gain (large food quantity), high-risk (1 in 4 probability of receiving an air-puff) option (HGRAP) or a low-gain (small food quantity), no-risk (of an air-puff) (LGNAP) option. We assessed when arousal increased by considering different stages of the decision-making process (baseline, viewing, anticipation, reward periods) and investigated whether autonomic responses influenced choice outcome both immediately and in the subsequent trial. Chickens were faster to choose and their heart-rate significantly increased between the viewing and anticipation (post-decision, pre-outcome) periods when selecting the HGRAP option. This suggests that they responded physiologically to the impending risk. Additionally, arousal was greater following a HGRAP choice that resulted in an air-puff, but this did not deter chickens from subsequently choosing HGRAP. In contrast to human studies, we did not find evidence that somatic markers were activated during the viewing period, suggesting that arousal is not a good measure of avoidance in non-human animals