Electrically-pumped, broad-area, single-mode photonic crystal lasers

Planar broad-area single-mode lasers, with modal widths of the order of tens of microns, are technologically important for high-power applications and improved coupling efficiency into optical fibers. They may also find new areas of applications in on-chip integration with devices that are of similar size scales, such as for spectroscopy in microfluidic chambers or optical signal processing with micro-electromechanical systems. An outstanding challenge is that broad-area lasers often require external means of control, such as injection-locking or a frequency/spatial filter to obtain single-mode operation. In this paper, we propose and demonstrate effective index-guided, large-area, edge-emitting photonic crystal lasers driven by pulsed electrical current injection at the optical telecommunication wavelength of 1550nm. By suitable design of the photonic crystal lattice, our lasers operate in a single mode with a 1/e^2 modal width of 25μm and a length of 600μm

Examining Help-Seeking Attitudes in College Student-Athletes: Mental Health Literacy and Stigma

This study aimed to investigate the predictors of the attitudes of student-athletes toward seeking psychological help. Results from data collected from a sample of 79 college students in a Midwestern university indicated that mental health literacy, self-stigma, and public stigma combined significantly predicted attitudes toward help-seeking. However, when self-stigma and public stigma were controlled, only mental health literacy significantly predicted attitudes toward help-seeking. These findings suggest that mental health literacy is a crucial factor in predicting help-seeking behaviors among college student-athletes, and that stigma can impact help-seeking behaviors. Additionally, mental health literacy was positively correlated with attitudes toward help-seeking, indicating that student-athletes with greater mental health knowledge may be more likely to seek professional help and understand available resources. The implications of the study are discussed

An exploratory investigation of proximity control in a large-group unstructured setting

Proximity control is a common component of many classroom management strategies and has been shown to reduce disruptive behavior as well as increase academic engagement among students. Much of the research on proximity control to date has been conducted in structured classroom settings or in combination with other behavioral management techniques. This applied study investigated the effect of proximity control on student behavior in a large, unstructured setting using an ABAB withdrawal design. Results indicate that staff proximity was effective at reducing inappropriate student behavior. The study also explored the acceptability of the treatment among staff participants. Staff reported lower levels of acceptability for the implementation of proximity control compared to pretreatment methods of monitoring. A discussion of these findings and implications is included

Custom Integrated Circuit Design Using Open-Source Tools

Our team is exploring open-source tools for Very Large-Scale Integration (VLSI) design, used in the design of computer chips. In the past, most tools for chip design have been proprietary. We are exploring using open-source tools for both analog and digital VLSI design. By furthering our understanding of these tools, we aim to make VLSI design accessible to a broader market of people, in order to aid in education by removing the barriers to learning about integrated circuit design. This will allow for not just theoretical education but also practical experience in the chip design field for undergraduate students

Electrically Pumped, Edge-Emitting, Large-Area Photonic Crystal Lasers with Straight and Angled Facets

We propose and demonstrate electrically pumped, edge-emitting, large-area photonic crystal lasers. Effective index-guided and Bragg-guided lasing modes are obtained depending on the design of photonic crystal and facets

A mechanochemical model of striae distensae

Striae distensae, otherwise known as stretch marks, are common skin lesions found in a variety of clinical settings. They occur frequently during adolescence or pregnancy where there is rapid tissue expansion and in clinical situations associated with corticosteroid excess. Heralding their onset is the appearance of parallel inflammatory streaks aligned perpendicular to the direction of skin tension. Despite a considerable amount of investigative research, the pathogenesis of striae remains obscure. The interpretation of histologic samples – the major investigative tool – demonstrates an association between dermal lymphocytic inflammation, elastolysis, and a scarring response. Yet the primary causal factor in their aetiology is mechanical; either skin stretching due to underlying tissue expansion or, less frequently, a compromised dermis affected by normal loads. In this paper, we investigate the pathogenesis of striae by addressing the coupling between mechanical forces and dermal pathology. We develop a mathematical model that incorporates the mechanical properties of cutaneous fibroblasts and dermal extracellular matrix. By using linear stability analysis and numerical simulations of our governing nonlinear equations, we show that this quantitative approach may provide a realistic framework that may account for the initiating events

Einfluss der Witterungsbedingungen auf den Ertrag von in Luxemburg typischen Körnerleguminosen

Meteorologische Parameter wurden mit Ertragsparametern für Körnerleguminosen wie Ackerbohne, Erbse und Sojabohne gängiger Sorten in Luxemburg verglichen. Die Ergebnisse zeigen signifikante Korrelationen zwischen Niederschlag, relativer Luftfeuchtigkeit, Temperatur und Ertragsparametern

Examination of Msh6- and Msh3-deficient Mice in Class Switching Reveals Overlapping and Distinct Roles of MutS Homologues in Antibody Diversification

Somatic hypermutation and class switch recombination (CSR) contribute to the somatic diversification of antibodies. It has been shown that MutS homologue (Msh)6 (in conjunction with Msh2) but not Msh3 is involved in generating A/T base substitutions in somatic hypermutation. However, their roles in CSR have not yet been reported. Here we show that Msh6−/− mice have a decrease in CSR, whereas Msh3−/− mice do not. When switch regions were analyzed for mutations, deficiency in Msh6 was associated with an increase in transition mutations at G/C basepairs, mutations at RGYW/WRCY hotspots, and a small increase in the targeting of G/C bases. In addition, Msh6−/− mice exhibited an increase in the targeting of recombination sites to GAGCT/GGGGT consensus repeats and hotspots in Sγ3 but not in Sμ. In contrast to Msh2−/− mice, deficiency in Msh6 surprisingly did not change the characteristics of Sμ-Sγ3 switch junctions. However, Msh6−/− mice exhibited a change in the positioning of Sμ and Sγ3 junctions. Although none of these changes were seen in Msh3−/− mice, they had a higher percentage of large inserts in their switch junctions. Together, our data suggest that MutS homologues Msh2, Msh3, and Msh6 play overlapping and distinct roles during antibody diversification processes