The gauging of two-dimensional bosonic sigma models on world-sheets with defects

We extend our analysis of the gauging of rigid symmetries in bosonic two-dimensional sigma models with Wess-Zumino terms in the action to the case of world-sheets with defects. A structure that permits a non-anomalous coupling of such sigma models to world-sheet gauge fields of arbitrary topology is analysed, together with obstructions to its existence, and the classification of its inequivalent choices.Comment: 94 pages, 1 figur

Principal infinity-bundles - General theory

The theory of principal bundles makes sense in any infinity-topos, such as that of topological, of smooth, or of otherwise geometric infinity-groupoids/infinity-stacks, and more generally in slices of these. It provides a natural geometric model for structured higher nonabelian cohomology and controls general fiber bundles in terms of associated bundles. For suitable choices of structure infinity-group G these G-principal infinity-bundles reproduce the theories of ordinary principal bundles, of bundle gerbes/principal 2-bundles and of bundle 2-gerbes and generalize these to their further higher and equivariant analogs. The induced associated infinity-bundles subsume the notions of gerbes and higher gerbes in the literature. We discuss here this general theory of principal infinity-bundles, intimately related to the axioms of Giraud, Toen-Vezzosi, Rezk and Lurie that characterize infinity-toposes. We show a natural equivalence between principal infinity-bundles and intrinsic nonabelian cocycles, implying the classification of principal infinity-bundles by nonabelian sheaf hyper-cohomology. We observe that the theory of geometric fiber infinity-bundles associated to principal infinity-bundles subsumes a theory of infinity-gerbes and of twisted infinity-bundles, with twists deriving from local coefficient infinity-bundles, which we define, relate to extensions of principal infinity-bundles and show to be classified by a corresponding notion of twisted cohomology, identified with the cohomology of a corresponding slice infinity-topos. In a companion article [NSSb] we discuss explicit presentations of this theory in categories of simplicial (pre)sheaves by hyper-Cech cohomology and by simplicial weakly-principal bundles; and in [NSSc] we discuss various examples and applications of the theory.Comment: 46 pages, published versio

WZW orientifolds and finite group cohomology

The simplest orientifolds of the WZW models are obtained by gauging a Z_2 symmetry group generated by a combined involution of the target Lie group G and of the worldsheet. The action of the involution on the target is by a twisted inversion g \mapsto (\zeta g)^{-1}, where \zeta is an element of the center of G. It reverses the sign of the Kalb-Ramond torsion field H given by a bi-invariant closed 3-form on G. The action on the worldsheet reverses its orientation. An unambiguous definition of Feynman amplitudes of the orientifold theory requires a choice of a gerbe with curvature H on the target group G, together with a so-called Jandl structure introduced in hep-th/0512283. More generally, one may gauge orientifold symmetry groups \Gamma = Z_2 \ltimes Z that combine the Z_2-action described above with the target symmetry induced by a subgroup Z of the center of G. To define the orientifold theory in such a situation, one needs a gerbe on G with a Z-equivariant Jandl structure. We reduce the study of the existence of such structures and of their inequivalent choices to a problem in group-\Gamma cohomology that we solve for all simple simply-connected compact Lie groups G and all orientifold groups \Gamma = Z_2 \ltimes Z.Comment: 48+1 pages, 11 figure

Topological defects for the free boson CFT

Two different conformal field theories can be joined together along a defect line. We study such defects for the case where the conformal field theories on either side are single free bosons compactified on a circle. We concentrate on topological defects for which the left- and right-moving Virasoro algebras are separately preserved, but not necessarily any additional symmetries. For the case where both radii are rational multiples of the self-dual radius we classify these topological defects. We also show that the isomorphism between two T-dual free boson conformal field theories can be described by the action of a topological defect, and hence that T-duality can be understood as a special type of order-disorder duality.Comment: 43 pages, 4 figure

A combined intervention strategy to increase linkage to and retention in substance use treatment for individuals accessing hospital-based services: study protocol

BackgroundIn 2020, New Mexico had the highest alcohol related death and the 11th highest drug overdose rate in the U.S. Towards the long-term goal of addressing this public health problem, we are implementing and evaluating an multi-level intervention designed to identify adults at risk of substance use disorder (SUD) and encourage linkage to and retention in treatment. The first level includes equipping the ED and medical inpatient units of a safety-net hospital with a method to screen individuals at risk of a SUD. The second level includes Seeking Safety (SS), a trauma-specific treatment for PTSD and SUD; and pharmacotherapy for SUD. Motivational Interviewing (MI) is used throughout both levels. Using the SPIRIT guidelines and checklist, this study protocol describes the multi-level intervention and the methodology we are using to assess feasibility and effectiveness.MethodsWe are using a Type 1 hybrid implementation design with a non-randomized approach (ISRCTN registration # ISRCTN33100750). We aim to enroll 110 adults (≧18) who screen positive for unhealthy use of alcohol, prescription medications (used nonmedically) and/or illicit drugs. Peer support workers are responsible for screening, using MI to increase engagement in screening and treatment and delivery of SS. Pharmacotherapy is provided by addiction clinical specialists. Treatment is provided post hospital discharge via telehealth to increase access to care. Participants are identified through (1) review of electronic health records for individuals with a chief or secondary complaint or mental health condition relating to alcohol and/or other drug use, (2) referrals from clinical staff and (3) screening in the ED and medical inpatient units. Feasibility is being measured through process data. Effectiveness will be determined by changes in two primary outcomes: (i) PTSD symptom severity; and (ii) substance use.DiscussionOur study will expand on research related to the implementation of treatment strategies for patients presenting at EDs and admitted to medical inpatients units wherein there is a significant window of opportunity to link patients with follow-up behavioral and clinical services for alcohol and/or drug misuse. The challenges associated with implementation and strategies that have been helpful to address these challenges will further inform the field

Miscarriage and stillbirth following maternal Zika virus infection in nonhuman primates.

Zika virus (ZIKV) infection is associated with congenital defects and pregnancy loss. Here, we found that 26% of nonhuman primates infected with Asian/American ZIKV in early gestation experienced fetal demise later in pregnancy despite showing few clinical signs of infection. Pregnancy loss due to asymptomatic ZIKV infection may therefore be a common but under-recognized adverse outcome related to maternal ZIKV infection

A Cell of One’s Own? Incarceration and Other Turning Points in Women’s Journeys to Desistance

Research has shown the importance of turning points in desistance from criminal behavior. Using qualitative data from a sample of 100 formerly incarcerated mothers interviewed about their criminal behavior, this article explores their descriptions of transition moments and whether and how those moments affected their criminal behavior. The findings indicate that whereas parenting emerges as a turning point, the practical difficulties of reentry may reduce the impact of mothering on women’s desistance. More self-focused turning points, such as those due to incarceration, arrest, and sobriety appeared to be particularly important to the women’s desistance. This article emphasizes the need for research into the subjective and environmental factors that affect women’s desistance behaviors

"‘We just want to be treated with respect!’: Using restorative approaches and the dramatic arts to build positive relationships between the police and young people"

This article explores the application of an ambitious arts-based restorative intervention that has been applied in a direct response to perceived issues with procedural justice, legitimacy and community relations between police and young people. The research focuses on a series of Youth Forums that took place in the West of England, employed as an attempt to improve strained relationships between both parties. It reports on detailed ethnographic research of the Forum processes and procedures presenting this primary evidence in light of the existing literature on police legitimacy and procedural justice in police-youth encounters. The findings suggest that community-based arts programmes can be a powerful and effective tool for challenging entrenched views with the potential to improve future encounters between police and young people; and that the relevance and effectiveness of arts-based interventions can be increased by combining with restorative justice principles

A streptococcal lipid toxin induces membrane permeabilization and pyroptosis leading to fetal injury

Group B streptococci (GBS) are Gram-positive bacteria that cause infections in utero and in newborns. We recently showed that the GBS pigment is hemolytic and increased pigment production promotes bacterial penetration of human placenta. However, mechanisms utilized by the hemolytic pigment to induce host cell lysis and the consequence on fetal injury are not known. Here, we show that the GBS pigment induces membrane permeability in artificial lipid bilayers and host cells. Membrane defects induced by the GBS pigment trigger K+ efflux leading to osmotic lysis of red blood cells or pyroptosis in human macrophages. Macrophages lacking the NLRP3 inflammasome recovered from pigment-induced cell damage. In a murine model of in utero infection, hyperpigmented GBS strains induced fetal injury in both an NLRP3 inflammasome-dependent and NLRP3 inflammasome-independent manner. These results demonstrate that the dual mechanism of action of the bacterial pigment/lipid toxin leading to hemolysis or pyroptosis exacerbates fetal injury and suggest that preventing both activities of the hemolytic lipid is likely critical to reduce GBS fetal injury and preterm birth

Preterm birth: inflammation, fetal injury and treatment strategies

Preterm birth (PTB) is the leading cause of childhood mortality in children under 5 and accounts for approximately 11% of births worldwide. Premature babies are at risk of a number of health complications, notably cerebral palsy, but also respiratory and gastrointestinal disorders. Preterm deliveries can be medically indicated/elective procedures or they can occur spontaneously. Spontaneous PTB is commonly associated with intrauterine infection/inflammation. The presence of inflammatory mediators in utero has been associated with fetal injury, particularly affecting the fetal lungs and brain. This review will outline (i) the role of inflammation in term and PTB, (ii) the effect infection/inflammation has on fetal development and (iii) recent strategies to target PTB. Further research is urgently required to develop effective methods for the prevention and treatment of PTB and above all, to reduce fetal injury