No more walls! A tale of modularity, symmetry, and wall crossing for 1/4 BPS dyons

Abstract We determine the generating functions of 1/4 BPS dyons in a class of 4d N $$\mathcal{N}$$ = 4 string vacua arising as CHL orbifolds of K3 × T 2, a classification of which has been recently completed. We show that all such generating functions obey some simple physical consistency conditions that are very often sufficient to fix them uniquely. The main constraint we impose is the absence of unphysical walls of marginal stability: discontinuities of 1/4 BPS degeneracies can only occur when 1/4 BPS dyons decay into pairs of 1/2 BPS states. Formally, these generating functions in spacetime can be described as multiplicative lifts of certain supersymmetric indices (twining genera) on the worldsheet of the corresponding nonlinear sigma model on K3. As a consequence, our procedure also leads to an explicit derivation of almost all of these twining genera. The worldsheet indices singled out in this way match precisely a set of functions of interest in moonshine, as predicted by a recent conjecture

Heterotic sigma models on T8T^8 and the Borcherds automorphic form Φ12\Phi_{12}

We consider the spectrum of BPS states of the heterotic sigma model with $(0,8)$ supersymmetry and $T^8$ target, as well as its second-quantized counterpart. We show that the counting function for such states is intimately related to Borcherds' automorphic form $\Phi_{12}$, a modular form which exhibits automorphy for $O(2,26;{\mathbb Z})$. We comment on possible implications for Umbral moonshine and theories of AdS$_3$ gravity.Comment: 12 pages; v2 error (involving fermion zero modes) correcte

Experimental Investigation of Stagnation Point Electrodes

Space resolved measurements for electrode in stagnation flow of arc heated plasm

Ethics and Childhood Vaccination Policy in the United States

Childhood immunization involves a balance between parents' autonomy in deciding whether to immunize their children and the benefits to public health from mandating vaccines. Ethical concerns about pediatric vaccination span several public health domains, including those of policymakers, clinicians, and other professionals. In light of ongoing developments and debates, we discuss several key ethical issues concerning childhood immunization in the United States and describe how they affect policy development and clinical practice. We focus on ethical considerations pertaining to herd immunity as a community good, vaccine communication, dismissal of vaccine-refusing families from practice, and vaccine mandates. Clinicians and policymakers need to consider the nature and timing of vaccine-related discussions and invoke deliberative approaches to policy-making

The influence of resuscitation preferences on obstetrical management of periviable deliveries

Objective Determine the relative influence of patient's resuscitation preferences on periviable delivery management. Methods Surveyed 295 obstetrician-gynecologists about managing periviable preterm premature rupture of membranes. Across 10 vignettes, we systematically varied gestational age; occupation; method of conception; and resuscitation preference. Physicians rated their likelihood (0-10) of proceeding with induction, steroids, and cesarean. Data were analyzed via conjoint analysis. Results 205 physician responses were included. Median ratings for management decisions were: induction 1.89; steroids 5.00; cesarean for labor 3.89; cesarean for distress 4.11. Gestational age had the greatest influence on physician ratings across all decisions (importance values ranging from 72.6-86.6), followed by patient's resuscitation preference (range= 9.3-21.4). Conclusion Gestational age is weighted more heavily than patients’ resuscitation preferences in obstetricians’ decision-making for periviable delivery management. Misalignment of antenatal management with parental resuscitation preferences may adversely affect periviable outcomes. Interventions are needed to facilitate more patient-centered decision-making in periviable care

Vaccine strategies: Optimising outcomes

AbstractSuccessful immunisation programmes generally result from high vaccine effectiveness and adequate uptake of vaccines. In the development of new vaccination strategies, the structure and strength of the local healthcare system is a key consideration. In high income countries, existing infrastructures are usually used, while in less developed countries, the capacity for introducing new vaccines may need to be strengthened, particularly for vaccines administered beyond early childhood, such as the measles or human papillomavirus (HPV) vaccine. Reliable immunisation service funding is another important factor and low income countries often need external supplementary sources of finance. Many regions also obtain support in generating an evidence base for vaccination via initiatives created by organisations including World Health Organization (WHO), the Pan American Health Organization (PAHO), the Agence de Médecine Préventive and the Sabin Vaccine Institute. Strong monitoring and surveillance mechanisms are also required. An example is the efficient and low-cost approaches for measuring the impact of the hepatitis B control initiative and evaluating achievement of goals that have been established in the WHO Western Pacific region. A review of implementation strategies reveals differing degrees of success. For example, in the Americas, PAHO advanced a measles-mumps-rubella vaccine strategy, targeting different population groups in mass, catch-up and follow-up vaccination campaigns. This has had much success but coverage data from some parts of the region suggest that children are still not receiving all appropriate vaccines, highlighting problems with local service infrastructures. Stark differences in coverage levels are also observed among high income countries, as is the case with HPV vaccine implementation in the USA versus the UK and Australia, reflecting differences in delivery settings. Experience and research have shown which vaccine strategies work well and the factors that encourage success, which often include strong support from government and healthcare organisations, as well as tailored, culturally-appropriate local approaches to optimise outcomes

A qualitative study of healthcare provider awareness and informational needs regarding the nine-valent HPV vaccine

The 9-valent Human Papillomavirus (HPV) vaccine, 9vHPV, was licensed in the U.S. in December, 2014. We assessed healthcare provider (HCP) awareness of the newly approved vaccine and identified questions HCPs have about the vaccine. As part of a larger study, we used semi-structured interviews to ask 22 pediatric HCPs about their awareness of 9vHPV, questions they have about the vaccine, and questions they anticipate from patients and parents. Interviews were audio-recorded and transcribed then analyzed using inductive content analysis. Over half were aware of the vaccine but few HCPs claimed to be familiar with it. HCPs indicated several questions with common themes pertaining to efficacy, side effects, and cost. Only half of HCPs believed patients or parents would have questions. The results suggest strategies and areas for health systems and public health organizations to target in order to resolve unmet educational needs among HCPs regarding 9vHPV

Healthcare providers’ beliefs and attitudes regarding risk compensation following HPV vaccination

Background Provider recommendation is a significant predictor of HPV vaccine uptake. Prior research suggests that concerns regarding risk compensation could cause some providers to hesitate recommending the HPV vaccine. Methods During 15–30 min semi-structured interviews in early 2015, 22 U.S. pediatric providers were asked about their beliefs regarding sexual risk compensation and cervical cancer screening following HPV vaccination. Providers were asked if these beliefs result in reservations recommending the vaccine. Interviews were audio-recorded, transcribed, and analyzed using inductive content analysis. Results None of the providers believed the HPV vaccine would result in risky sexual behavior. Half indicated it was better to start vaccination early, before sexual activity was a worry. Others noted that patients’ risky behavior decisions happen independently of vaccination. When providers were asked if they were concerned about decreased cervical cancer screening, half said they did not know and some stated they had never thought about it before. The main themes addressed were the significant time lapse between vaccination and screening and that women tend to get over-screened as opposed to under-screened. Conclusion Providers were generally in favor of HPV vaccination and do not perceive risk compensation as a barrier to HPV recommendation

Health care providers’ perceptions of use and influence of clinical decision support reminders: qualitative study following a randomized trial to improve HPV vaccination rates

Background Human Papillomavirus (HPV) leads to serious health issues and remains the most common sexually transmitted infection. Despite availability of effective vaccines, HPV vaccination rates are suboptimal. Furthermore, providers recommend the HPV vaccine less than half the time for eligible patients. Prior informatics research has demonstrated the effectiveness of computer-based clinical decision support (CDS) in changing provider behavior, especially in the area of preventative services. Methods Following a randomized clinical trial to test the effect of a CDS intervention on HPV vaccination rates, we conducted semi-structured interviews with health care providers to understand whether they noticed the CDS reminders and why providers did or did not respond to the prompts. Eighteen providers, a mix of medical doctors and nurse practitioners, were interviewed from five publicly-funded, urban health clinics. Interview data were qualitatively analyzed by two independent researchers using inductive content analysis. Results While most providers recalled seeing the CDS reminders, few of them perceived the intervention as effective in changing their behavior. Providers stated many reasons for why they did not perceive a change in their behavior, yet the results of the trial showed HPV vaccination rates increased as a result of the intervention. Conclusions CDS reminders may be effective at changing provider behavior even if providers perceive them to be of little use. Trial registration ClinicalTrials.gov Identifier: NCT02551887 , Registered on September 15, 2015 Electronic supplementary material The online version of this article (doi:10.1186/s12911-017-0521-6) contains supplementary material, which is available to authorized users