The Selberg zeta function for convex co-compact Schottky groups

We give a new upper bound on the Selberg zeta function for a convex co-compact Schottky group acting on ${\mathbb H}^{n+1}$: in strips parallel to the imaginary axis the zeta function is bounded by $\exp (C |s|^\delta)$ where $\delta$ is the dimension of the limit set of the group. This bound is more precise than the optimal global bound $\exp (C |s|^{n+1})$, and it gives new bounds on the number of resonances (scattering poles) of $\Gamma \backslash {\mathbb H}^{n+1}$. The proof of this result is based on the application of holomorphic $L^2$-techniques to the study of the determinants of the Ruelle transfer operators and on the quasi-self-similarity of limit sets. We also study this problem numerically and provide evidence that the bound may be optimal. Our motivation comes from molecular dynamics and we consider $\Gamma \backslash {\mathbb H}^{n+1}$ as the simplest model of quantum chaotic scattering. The proof of this result is based on the application of holomorphic $L^2$-techniques to the study of the determinants of the Ruelle transfer operators and on the quasi-self-similarity of limit sets

A Bose-Einstein Condensate in a Uniform Light-induced Vector Potential

We use a two-photon dressing field to create an effective vector gauge potential for Bose-condensed Rb atoms in the F=1 hyperfine ground state. The dressed states in this Raman field are spin and momentum superpositions, and we adiabatically load the atoms into the lowest energy dressed state. The effective Hamiltonian of these neutral atoms is like that of charged particles in a uniform magnetic vector potential, whose magnitude is set by the strength and detuning of Raman coupling. The spin and momentum decomposition of the dressed states reveals the strength of the effective vector potential, and our measurements agree quantitatively with a simple single-particle model. While the uniform effective vector potential described here corresponds to zero magnetic field, our technique can be extended to non-uniform vector potentials, giving non-zero effective magnetic fields.Comment: 5 pages, submitted to Physical Review Letter

Effectiveness, Acceptability, and Feasibility of Digital Health Interventions for LGBTIQ+ Young People: Systematic Review

Background: Young people (aged 12-25 years) with diverse sexuality, gender, or bodily characteristics, such as those who identify as lesbian, gay, bisexual, transgender, intersex, or queer (LGBTIQ+), are at substantially greater risk of a range of mental, physical, and sexual health difficulties compared with their peers. Digital health interventions have been identified as a potential way to reduce these health disparities. Objective: This review aims to summarize the characteristics of existing evidence-based digital health interventions for LGBTIQ+ young people and to describe the evidence for their effectiveness, acceptability, and feasibility. Methods: A systematic literature search was conducted using internet databases and gray literature sources, and the results were screened for inclusion. The included studies were synthesized qualitatively. Results: The search identified 38 studies of 24 unique interventions seeking to address mental, physical, or sexual health–related concerns in LGBTIQ+ young people. Substantially more evidence-based interventions existed for gay and bisexual men than for any other population group, and there were more interventions related to risk reduction of sexually transmitted infections than to any other health concern. There was some evidence for the effectiveness, feasibility, and acceptability of these interventions overall; however, the quality of evidence is often lacking. Conclusions: There is sufficient evidence to suggest that targeted digital health interventions are an important focus for future research aimed at addressing health difficulties in LGBTIQ+ young people. Additional digital health interventions are needed for a wider range of health difficulties, particularly in terms of mental and physical health concerns, as well as more targeted interventions for same gender–attracted women, trans and gender-diverse people, and people with intersex variations

User acceptance of observation and response charts with a track and trigger system: A multisite staff survey

Aims and objectives: To examine user acceptance with a new format of charts for recording observations and as a prompt for responding to episodes of clinical deterioration in adult medical–surgical patients. Background: Improving recognition and response to clinical deterioration remains a challenge for acute healthcare institutions globally. Five chart templates were developed in Australia, combining human factors design principles with a track and trigger system for escalation of care. Two chart templates were previously tested in simulations, but none had been evaluated in clinical practice. Design: Prospective multisite survey of user acceptance of the charts in practice. Methods: New observation and response charts were trialled in parallel with existing charts for 24 hours across 36 adult acute medical–surgical wards, covering 108 shifts, in five Australian states. Surveys were completed by 477 staff respondents, with open-ended comments and narrative from short informal feedback groups providing elaboration and context of user experiences. Results: Respondents were broadly supportive of the chart format and content for monitoring patients, and as a prompt for escalating care. Some concerns were noted for chart size and style, use of ranges to graph vital signs and with specific human factors design features. Information and training issues were identified to improve usability and adherence to chart guidelines and to support improved detection and response for patients with clinical deterioration. Conclusions: This initial evaluation demonstrated that the charts were perceived as appropriate for documenting observations and as a prompt to detect clinical deterioration. Further evaluation after some minor modifications to the chart is recommended. Relevance to clinical practice: Explicit training on the principles and rationale of human factors chart design, use of embedded change management strategies and addressing practical issues will improve authentic engagement, staff acceptance and adoption by all clinical users when implementing a similar observation and response chart into practice

Regulation of Membrane Targeting of the G Protein-coupled Receptor Kinase 2 by Protein Kinase A and Its Anchoring Protein AKAP79

The beta 2 adrenergic receptor (beta 2AR) undergoes desensitization by a process involving its phosphorylation by both protein kinase A (PKA) and G protein-coupled receptor kinases (GRKs). The protein kinase A-anchoring protein AKAP79 influences beta 2AR phosphorylation by complexing PKA with the receptor at the membrane. Here we show that AKAP79 also regulates the ability of GRK2 to phosphorylate agonist-occupied receptors. In human embryonic kidney 293 cells, overexpression of AKAP79 enhances agonist-induced phosphorylation of both the beta 2AR and a mutant of the receptor that cannot be phosphorylated by PKA (beta 2AR/PKA-). Mutants of AKAP79 that do not bind PKA or target to the beta 2AR markedly inhibit phosphorylation of beta 2AR/PKA-. We show that PKA directly phosphorylates GRK2 on serine 685. This modification increases Gbeta gamma subunit binding to GRK2 and thus enhances the ability of the kinase to translocate to the membrane and phosphorylate the receptor. Abrogation of the phosphorylation of serine 685 on GRK2 by mutagenesis (S685A) or by expression of a dominant negative AKAP79 mutant reduces GRK2-mediated translocation to beta 2AR and phosphorylation of agonist-occupied beta 2AR, thus reducing subsequent receptor internalization. Agonist-stimulated PKA-mediated phosphorylation of GRK2 may represent a mechanism for enhancing receptor phosphorylation and desensitization

The mental health of nurses in acute teaching hospital settings: A cross-sectional survey

Background: Nursing is an emotionally demanding profession and deficiencies in nurses\u27 mental wellbeing, characterised by low vitality and common mental disorders, have been linked to low productivity, absenteeism and presenteeism. Part of a larger study of nurses\u27 health, the aim of this paper was to describe the mental health status and related characteristics of nurses working in two acute metropolitan teaching hospitals. Methods: A cross sectional survey design was used. Results: A total of 1215 surveys were distributed with a usable response rate of 382 (31.4%). Altogether 53 nurses (14%) reported a history of mental health disorders, of which n=49 (13%) listed diagnoses of anxiety and/or depression; 22 (6%) were currently taking psychoactive medication. Symptoms that could potentially indicate a mental health issue were more common, with 248 (65.1%) reporting they had experienced symptoms sometimes or often in the last 12month. Conclusion: Nurses and their managers should strive to create workplaces where working practices promote nurses\u27 health and wellbeing, or at least are configured to minimise deleterious effects; where both nurses and their managers are aware of the potential for negative effects on the mental health of the workforce; where cultures are such that this can be discussed openly without fear of stigma or denigration