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Phases of quartic scalar theories and PT symmetry
Get PDFFor quantum mechanical anharmonic oscillator-type Hamiltonians, it is shown that there is a relation between the energy eigenvalues of parity symmetric and PT-symmetric phases for weak coupling. The possibility of such a relation was conjectured by Ai, Bender, and Sarkar on examining the imaginary part of the ground state energy using path integrals. In the weak coupling limit, we show that the conjecture is true also for the real part of the ground state energy and of the excited state energies. However, the conjecture is false for strong coupling. The analogous relation for partition functions in zero spacetime dimensions is valid for many cases. However O(N) symmetric multicomponent scalar fields, with N>1 and a quartic interaction, do not satisfy the conjecture for zero and one dimensional spacetime. The possibility that the conjecture is valid, for a single component field theory in higher dimensional spacetimes, is discussed in a simplified model.</p
“Bigger lows, but higher highs”: A qualitative exploration of the similarities and differences in quality of life of middle-aged and older autistic and non-autistic adults.
Get PDF*Francis and Hershman as joint-first authorsABSTRACTBackground: Autistic adults often report lower subjective quality of life (QoL) than non-autistic adults. Despite older age also often being associated with lower QoL, little is known about the first-hand experiences of, and influences on, QoL for middle-aged and older autistic adults compared with their non-autistic peers.Method: Thirty-three participants (autistic n=15, non-autistic n=18) aged 50-89 years completed semi-structured interviewed that explored their QoL. Responses were thematically analysed, and themes were compared to identify similarities and differences between groups.Results: Both autistic and non-autistic groups reported similar QoL experiences, but with subtle differences. Social support from family and friends was important for both groups. Both noted shrinking social networks with age, but the non-autistic group was often less satisfied with their social lives. Concerns about health and sleep changes were common, but autistic participants often mentioned persistent mental health issues affecting their wellbeing. Autistic individuals also highlighted sensorysensitivities and difficulties with change. Receiving their autism diagnosis was significant for autistic participants, aiding self-acceptance. Acceptance of age-related changes was common in both groups, but the autistic group was more willing to seek support, while the non-autistic group often saw asking for help as losing their independence.Conclusions: These findings highlight similarities and differences in aspects relevant to QoL for middle-aged and older autistic and non-autistic adults. While many similarities were found, the autistic group reported subtle differences in their experiences. Experiences such as social connectedness and coping with change could be targeted to improve the QoL of ageing autistic adults
Generalized hydrodynamics: A perspective
Get PDFConventional hydrodynamics describes systems with few long-lived excitations. In one dimension, however, many experimentally relevant systems feature a large number of long-lived excitations and conserved quantities even at high temperature, because they are proximate to integrable limits. Such models cannot be treated using conventional hydrodynamics. The framework of generalized hydrodynamics (GHD) was recently developed to treat the dynamics of one-dimensional models: It combines ideas from integrability, hydrodynamics, and kinetic theory to come up with a quantitative theory of transport. GHD has successfully settled several long-standing questions about one-dimensional transport; it has also been leveraged to study dynamical questions beyond the transport of conserved quantities and to systems that are not integrable. In this article, we introduce the main ideas and predictions of GHD, survey some of the most recent theoretical extensions and experimental tests of the GHD framework, and discuss some open questions in transport that the GHD perspective might elucidate.</p
Characterization of RufT Thioesterase Domain Reveals Insights into Rufomycin Cyclization and the Biosynthetic Origin of Rufomyazine
Get PDFThe nonribosomal cyclic peptides (NRcPs) rufomycins, produced by Streptomyces atratus, have attracted attention as antimycobacterials. Thus, there has been interest in engineering the corresponding biosynthetic pathway to produce novel derivatives. We have thus investigated the type I thioesterase (TE) of the NRPS RufT that catalyzes rufomycin peptide macrocyclization to understand its tolerance to changes in substrate peptide sequence. In contrast to our previously reported efficient cyclization chemistry, the recombinant RufT-TE domain and RufT-PCP-TE didomain, while tolerating some substrate structural changes, both produce high levels of hydrolyzed peptide. Closer analysis led to the identification of the natural product diketopiperazine rufomyazine in assays. The data indicate, with significant implications for rufomycin production, that RufT produces both cyclic and linear peptides. We propose that rufomyazine forms non-enzymatically from the linear peptide. In addition, it provides evidence for TE domains as gatekeepers in NRPS biosynthesis. </p
Forget the facts:a humanistic approach to addressing contemporary issues in urban waste management
No full textDespite public knowledge of the impacts of litter on environmental preservation efforts, volumes of litter continue to grow at alarming rates. In reviewing the history of litter research, a trend of focusing primarily on changing behaviour is apparent, while there remains very little understanding of the behaviour itself. By leveraging principles of radical research, a focus on understanding how items are littered identifies that a large portion of litter is generated unintentionally, calling into question the effectiveness of communication with a public who is not aware of the consequences of their actions
Organizational Engagement With Poverty: A Review and Reorientation
No full textRecognizing the potential contributions businesses can make to address the grand challenge of global poverty, management scholars have increasingly turned research attention to poverty. We conducted an integrative review of poverty studies in the organizational literature spanning from 1985 to 2022. Based on the review, we clarify poverty as a significant lack of market-oriented resources, opportunities, and capabilities. Further, we develop a framework that captures the ways in which organizational practices offer the poor, or deprive them of, resources, opportunities, and capabilities, and thereby contribute to poverty alleviation or aggravation respectively. Moreover, our framework identifies the necessary support conditions for an organization to effectively combat poverty. We conclude by proposing a research agenda aimed at advancing management scholarship on poverty
Psychedelic-assisted treatment for substance use disorder:A narrative systematic review
Get PDFBackground and aimsThis is the first systematic review of the extant literature on all major psychedelic-assisted treatment for alcohol use disorder (AUD), tobacco use disorder (TUD) and other substance use disorders (SUD). We aimed to summarise the evidence for efficacy of psychedelic-assisted treatment for AUD, TUD, and SUD; to evaluate its quality; and to offer recommendations for research.MethodsThis was a prospectively registered narrative systematic review of open-label, randomised controlled trials (RCT), and observational studies of d-lysergic acid diethylamide (LSD), mescaline, psilocybin, ayahuasca, ketamine, ibogaine and 3,4-methylenedioxymethamphetamine (MDMA). Eligible studies had SUD outcome measures including craving, substance use, relapse, and remission. Study quality was evaluated using the Cochrane Collaboration Risk of Bias (RoB), and Cochrane Collaboration RoB in Non-randomised Studies of Interventions tool. Certainty of evidence for RCTs was judged using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) tool.Findings37 studies (2035 participants) were reviewed: LSD (14; n = 1047); mescaline (1; n = 7); psilocybin (4; n = 135); ayahuasca (3; n = 101); ketamine (10; n = 579); ibogaine (5; n = 166); and MDMA (1; n = 14). There were no serious adverse events reported in any study. A two-centre, placebo-controlled, phase 2 superiority RCT of psilocybin for AUD, and a two-centre, double-blind, four-arm, placebo-controlled phase 2 RCT of ketamine for AUD yielded the best evidence of efficacy. Progression support to a phase 3 trials was secured from an open-label phase 2 study of psilocybin for TUD and nine phase 2 RCTs of ketamine for AUD, cannabis use disorder, cocaine use disorder, and opioid use disorder (all nine with high-RoB and low-GRADE evidence certainty).ConclusionsPsilocybin-assisted treatment for alcohol use disorder appears to have the best evidence of efficacy among all major psychedelic-assisted treatments for alcohol, tobacco, and other substance use disorders. Future research of psychedelic-assisted treatment should report all safety events; screen for person-level characteristics indicating that psychedelic-assisted substance use disorders treatment is contraindicated; strive to mitigate blinding of participants to interventions; use factorial designs for drug and psychotherapy randomised controlled trials; and build consensus for a field-specific Core Outcome Set.<p/