Periportal Capsulotomy: A Technique for Limited Violation of the Hip Capsule During Arthroscopy for Femoroacetabular Impingement.

Hip arthroscopy has become the standard treatment for symptomatic femoroacetabular impingement as patients have shown good outcomes and high satisfaction with this intervention. However, capsular management to gain access for intra-articular procedures remains greatly debated. Capsular closure is advocated particularly in the setting of interportal or T-capsulotomy to avoid complications of instability or nonhealing capsule. We introduce a technique for capsular management through a limited periportal capsulotomy during arthroscopic treatment of femoroacetabular impingement. In using dilation of the anterolateral and mid-anterior portals without completion of a full interportal capsulotomy, the stabilizing iliofemoral ligament is preserved. We have found that periportal capsulotomy provides safe and sufficient access to the hip joint without necessitating capsular closure

Performers as Teachers: A Case Study on How Two El Sistema-Inspired Teaching Artists\u27 Performance Identities Manifested During Instruction

Kids’ Orchestra (KO) is an afterschool El Sistema-inspired program in Baton Rouge, Louisiana with a Title I school district, which employs a high percentage of musicians who identify strongly as performers. During the 2017-2018 school year, 52 of 59 KO teaching artists were considered professional musicians with training in music performance, with no educational background and/or prior experience in music education. The recent development of ESI programs across the United States has fostered claims of using music education as a way to bring social change to the community it works in. Research exploring the specific nature of the pedagogy in these types of programs has become a necessity. Therefore, the purpose of this study was to create a portrait of two professional musicians who are teaching artists at KO and explore how their strong performer identities influence and impact their pedagogy and teaching styles. In this qualitative instrumental case study, I observed, interviewed, and co-reflected with two teaching artists who were professional musicians and from vastly different cultural backgrounds. Kevin and Paulo are both male, one from the U.S. having grown up in traditional American large ensembles while Paulo grew up in Venezuela as an active participant in El Sistema orchestras before attending college in the U.S. Both participants had been placed as teaching artists for KO for at least two full academic years and were actively involved in the Baton Rouge music scene. Findings revealed that the two participants’ performance identities manifested in several different ways. Kevin’s main goal for his percussion class was music literacy while Paulo valued the social aspects of music making over technique and literacy. Both teaching artists had trouble giving their students feedback and described a disconnect between having fun and learning music. Finally, I describe the two ways in which the participants differentiated instruction in their classes with varied ages and ability levels: the “helper” and part differentiation

Planar Ion Trap Geometry for Microfabrication

We describe a novel high aspect ratio radiofrequency linear ion trap geometry that is amenable to modern microfabrication techniques. The ion trap electrode structure consists of a pair of stacked conducting cantilevers resulting in confining fields that take the form of fringe fields from parallel plate capacitors. The confining potentials are modeled both analytically and numerically. This ion trap geometry may form the basis for large scale quantum computers or parallel quadrupole mass spectrometers. PACS: 39.25.+k, 03.67.Lx, 07.75.+h, 07.10+CmComment: 14 pages, 16 figure

Subjective Well-Being and Intergenerational Mobility in South Africa

Using data on individuals from the National Income Dynamics Study (NIDS), this paper analyzes the relationship between intergenerational mobility and subjective well-being for two cohorts of South Africans. Subjective well-being has been measured using a multitude of factors, but the impact of changing economic mobility on reported life satisfaction has been less explored in the context of South Africa. Education and social mobility are the two mobility variables used to understand how changes in economic status relative to one’s parents affect self-reported well-being. This paper utilizes three methods of regression analysis for comparisons: cross-sectional, pooled cross-sectional, and panel (fixed effects and random effects methods). Estimates from each of these models indicate a positive effect of upward social mobility on reported well-being, however the effect is smaller for the apartheid cohort (older average age) compared to the post-apartheid cohort. The estimates for educational mobility give mixed results across the methods, so findings regarding the impact of educational mobility on reported well-being are less evident. These results suggest that improving one’s social mobility status positively impacts life satisfaction in South Africa, but that the magnitude of the effect is smaller for a post-apartheid generation of South Africans