Isomorphism and embedding of Borel systems on full sets

A Borel system consists of a measurable automorphism of a standard Borel space. We consider Borel embeddings and isomorphisms between such systems modulo null sets, i.e. sets which have measure zero for every invariant probability measure. For every t>0 we show that in this category there exists a unique free Borel system (Y,S) which is strictly t-universal in the sense that all invariant measures on Y have entropy <t, and if (X,T) is another free system obeying the same entropy condition then X embeds into Y off a null set. One gets a strictly t-universal system from mixing shifts of finite type of entropy at least t by removing the periodic points and "restricting" to the part of the system of entropy <t. As a consequence, after removing their periodic points the systems in the following classes are completely classified by entropy up to Borel isomorphism off null sets: mixing shifts of finite type, mixing positive-recurrent countable state Markov chains, mixing sofic shifts, beta shifts, synchronized subshifts, and axiom-A diffeomorphisms. In particular any two equal-entropy systems from these classes are entropy conjugate in the sense of Buzzi, answering a question of Boyle, Buzzi and Gomez.Comment: 17 pages, v2: correction to bibliograph

Sexual Orientation Intrusive Thoughts and Well-Being: The Mediating Role of Psychological Inflexibility

Sexual orientation intrusive thoughts are a debilitating form of obsessive compulsive disorder (OCD). The present study aimed to elucidate how psychological inflexibility and dysfunctional beliefs may impact the relationships of sexual orientation intrusive thoughts and obsessive-compulsive (OC) symptoms with well-being. A total of 181 undergraduate students completed measures of sexual orientation intrusive thoughts, OC symptoms, psychological inflexibility, dysfunctional beliefs, and well-being. Results indicated positive correlations between psychological inflexibility, sexual orientation intrusive thoughts, dysfunctional beliefs, and OC symptoms, along with negative correlations between well-being and sexual orientation intrusive thoughts, OC symptoms, dysfunctional beliefs and psychological inflexibility. Psychological inflexibility acted as a mediator between sexual orientation intrusive thoughts and well-being, and between OC symptoms and well-being. Dysfunctional beliefs were not a significant mediator. These results suggest that psychological inflexibility may partially explain the association between OC symptoms and well-being, pointing towards the need for future research on the impact of psychological inflexibility on well-being in the context of OC symptoms

Acceptance and Commitment Therapy for a Child With Misophonia: A Case Study

Misophonia, a condition involving hypersensitivity, anger, and/or disgust in response to specific noises (e.g., chewing, tapping), is highly underresearched in children. Several case studies point towards the utility of cognitive behavioral therapy and related treatments (e.g., acceptance and commitment therapy [ACT]). ACT presents a particularly promising option, as it focuses on building psychological flexibility in response to difficult internal experiences, rather than trying to remove or change them (e.g., responding effectively to irritation provoked by chewing). The present case study describes “Kelly” (pseudonym), a 12-year-old girl with moderately severe misophonia symptoms, who received a 16-session course of ACT for misophonia. At post-treatment, Kelly reported a decline to the mild range of misophonia, as well as re-engagement in activities that were important to her and clinically significant reductions in depressive symptoms. These results suggest that ACT may be an appropriate treatment for children with misophonia; however, much more research is warranted

Weight-Related Psychological Inflexibility as a Mediator Between Weight Self-Stigma and Health-Related Outcomes

Weight self-stigma, the internalization of negative societal stereotypes, is a problem amongst populations with high weight. Weight self-stigma is associated with psychological inflexibility and maladaptive health-related behaviors. In this study, we explore how weight-related psychological inflexibility may influence weight self-stigma and health-related outcomes in 79 adults with high weight. Participants were primarily white (92.4%) and female (82.3%), with an average age of 39.56 and average body mass index of 33.78. The present study uses baseline, self-report data from a larger trial. Results indicate that weight self-stigma was negatively correlated with maladaptive eating behaviors, weight, and mental health. Weight-related psychological inflexibility was found as a significant mediator for the relationship between weight self-stigma and emotional eating, sedentary behavior, and mental health. Weight-related psychological inflexibility did not mediate the relationships between weight self-stigma and other eating measures and physical activity. These results support targeting weight-related psychological inflexibility and weight self-stigma in interventions

Evaluating the Open and Engaged Components of Acceptance and Commitment Therapy in an Online Self-Guided Website: Results From a Pilot Trial

Online acceptance and commitment therapy (ACT) is promising for treating a range of psychological problems. Component research can further clarify which components are needed for optimal outcomes in what contexts. Online platforms provide a highly controlled format for such research. In this pilot trial, 55 adults were randomized to: ACT-Open (i.e., acceptance, defusion components), ACT-Engaged (i.e., values, committed action), or ACT-Combined (i.e., acceptance, defusion, values, committed action). Each condition was 12 sessions over six weeks, with assessments at baseline, posttreatment, and four-week follow-up. ACT-Open, ACT-Engaged, and ACT-Combined all significantly improved from pre- to post-treatment on mental health, psychosocial functioning, and components of psychological flexibility. Compared to ACT-Combined, ACT-Open improved less on psychosocial functioning at posttreatment, and ACT-Engaged worsened on functioning at follow-up. The platform was acceptable with high satisfaction ratings. Results support the feasibility of conducting online ACT component research, which will be tested in a fully powered non-inferiority trial

Childhood maltreatment, psychological resources, and depressive symptoms in women with breast cancer.

Childhood maltreatment is associated with elevated risk for depression across the human lifespan. Identifying the pathways through which childhood maltreatment relates to depressive symptoms may elucidate intervention targets that have the potential to reduce the lifelong negative health sequelae of maltreatment exposure. In this cross-sectional study, 271 women with early-stage breast cancer were assessed after their diagnosis but before the start of adjuvant treatment (chemotherapy, radiation, endocrine therapy). Participants completed measures of childhood maltreatment exposure, psychological resources (optimism, mastery, self-esteem, mindfulness), and depressive symptoms. Using multiple mediation analyses, we examined which psychological resources uniquely mediated the relationship between childhood maltreatment and depressive symptoms. Exposure to maltreatment during childhood was robustly associated with lower psychological resources and elevated depressive symptoms. Further, lower optimism and mindfulness mediated the association between childhood maltreatment and elevated depressive symptoms. These results support existing theory that childhood maltreatment is associated with lower psychological resources, which partially explains elevated depressive symptoms in a sample of women facing breast cancer diagnosis and treatment. These findings warrant replication in populations facing other major life events and highlight the need for additional studies examining childhood maltreatment as a moderator of treatment outcomes