Cosmic F- and D-strings

Macroscopic fundamental and Dirichlet strings have several potential instabilities: breakage, tachyon decays, and confinement by axion domain walls. We investigate the conditions under which metastable strings can exist, and we find that such strings are present in many models. There are various possibilities, the most notable being a network of (p,q) strings. Cosmic strings give a potentially large window into string physics.Comment: 27 pages, 5 figures; v. 5: JHEP style, added comments in section 2.

A performance review of novel adiposity indices for assessing insulin resistance in a pediatric Latino population

Introduction: Body mass index (BMI) percentile or BMI adjusted for age and sex is the most common anthropometric index to monitor and assess obesity in children. However, the ability of BMI to accurately predict insulin resistance (IR) in youth is debated. Determining the best method to noninvasively measure IR in the pediatric population is especially important due to the growing prevalence of type 2 diabetes mellitus (T2DM), which is more likely to develop in people with IR. Therefore, this study analyzed the performance of BMI against newer anthropometric indices in assessing IR in a pediatric Latino identifying sample. Methods: We studied 127 pediatric Latino participants from the Arizona Insulin Resistance (AIR) registry and performed linear regression analyses between various measures of IR and adiposity indices, including body mass index (BMI), triponderal mass index (TMI), body adiposity index (BAI), pediatric body adiposity index (pBAI), a body shape index (ABSI), abdominal volume index (AVI), waist to height ratio (WtHR) and waist to hip ratio (WHR). Log transformations of each index adjusted for age and sex and IR were used for the linear regressions. Additionally, we generated receiver operating characteristics (ROC) from logistic regressions between HOMA-IR and HOMA2IR against the same indices. Results: Using the homeostatic assessment of insulin resistance (HOMA-IR), HOMA2IR, the quantitative insulin-sensitivity check index (QUICKI), fasting serum insulin, and FPG/FSI to measure IR, we showed that BMI adjusted for age and sex performs similarly to many of the newer indices in our sample. The correlation coefficients for pBAI [R2: 0.27, 95% confidence interval: 0.88–1.81, p < 0.001] and BMI [R2: 0.27, 95% confidence interval: 0.92–1.92, p < 0.001] were the highest for HOMA-IR. Similarly, pBAI [R2: 0.29, 95% confidence interval: 0.88–1.72, p < 0.001] and BMI [R2: 0.29, 95% confidence interval: 0.93–1.83, p < 0.001] were the highest for HOMA2IR. A similar trend was observed with QUICKI, FSI, and FPG/FSI. ABSI had the lowest R2 value for all measures of IR. Area under the curve (AUC) values for the receiver operating characteristics (ROC) for HOMA-IR and HOMA2IR support these conclusions. Conclusions: BMI adjusted for age and sex, despite its usage and simplicity, still stacks up well against newer indices in our Latino sample. Testing these indices across larger samples is necessary to generalize these findings and translate performance to adults. 2022 McGraw, Kohler, Shaibi, Mandarino and Coletta.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Exploring Persona-Scenarios - Using Storytelling to Create Design Ideas

International audienceThis paper explores the persona-scenario method by investigating how the method can support project participants in generating shared understandings and design ideas. As persona-scenarios are stories we draw on narrative theory to define what a persona-scenario is and which narrative elements it should consist of. Based on an empirical study a key finding is that despite our inherent human ability to construct, tell, and interpret stories it is not easy to write and present a good, coherent, and design-oriented story without methodical support. The paper therefore contributes with guidelines that delineate a) what a design-oriented persona-scenario should consist of (product) and b) how to write it (procedure) in order to generate and validate as many, new, and shared understandings and design ideas as possible (purpose). The purpose of the guidelines is to facilitate the construction of persona-scenarios as good, coherent stories, which make sense to the storytellers and to the audience - and which therefore generate many, new, and shared understandings and design ideas