Inter- and intra-layer excitons in MoS2_2/WS2_2 and MoSe2_2/WSe2_2 heterobilayers

Accurately described excitonic properties of transition metal dichalcogenide heterobilayers (HBLs) are crucial to comprehend the optical response and the charge carrier dynamics of them. Excitons in multilayer systems posses inter or intralayer character whose spectral positions depend on their binding energy and the band alignment of the constituent single-layers. In this study, we report the electronic structure and the absorption spectra of MoS$_2$/WS$_2$ and MoSe$_2$/WSe$_2$ HBLs from first-principles calculations. We explore the spectral positions, binding energies and the origins of inter and intralayer excitons and compare our results with experimental observations. The absorption spectra of the systems are obtained by solving the Bethe-Salpeter equation on top of a G$_0$W$_0$ calculation which corrects the independent particle eigenvalues obtained from density functional theory calculations. Our calculations reveal that the lowest energy exciton in both HBLs possesses interlayer character which is decisive regarding their possible device applications. Due to the spatially separated nature of the charge carriers, the binding energy of inter-layer excitons might be expected to be considerably smaller than that of intra-layer ones. However, according to our calculations the binding energy of lowest energy interlayer excitons is only $\sim$ 20\% lower due to the weaker screening of the Coulomb interaction between layers of the HBLs. Therefore, it can be deduced that the spectral positions of the interlayer excitons with respect to intralayer ones are mostly determined by the band offset of the constituent single-layers. By comparing oscillator strengths and thermal occupation factors, we show that in luminescence at low temperature, the interlayer exciton peak becomes dominant, while in absorption it is almost invisible.Comment: 17 pages, 4 figure

Intra- and inter-examiner Reliability of Direct Facial Soft Tissue Measurements Using Digital Calipers

Background: The objective of this study is to determine if facial soft tissue measurements using digital calipers can be reliably taken by the same examiner and by a large group of examiners. Materials and Methods: Ten examiners performed a set of 18 in-clinic measurements on 10 female and 10 male dental students using a digital caliper twice over a 3-week period. The intra-class correlation coefficient and the Shrout-Fleiss method were used for the statistical analysis. Results: Anthropometric intra-examiner reliability was high for all measurements (none fell below R = 0.934). However, inter-examiner reliability exhibited a wide range of values, some reliable (nasal width at widest nostrils [R = 0.922] and subnasale to upper lip [R = 0.926]), and others unreliable [base of nose (R = 0.590), mouth height (R = 0.585), and soft tissue B point to gnathion (R = 0.623)]. Conclusions: Soft tissue measurements of clearly identifiable points measured by the same examiner produced highly consistent, accurate and reliable measurements. Soft tissue points with poor definition resulted in average-to-poor reliabilities measurements

Has Revenue Management Become Acceptable? Findings from an International Study on the Perceived Fairness of Rate Fences

Demand-based pricing is underused in many service industries, because customers are believed to perceive such pricing as unfair. Fencing can be highly effective in improving the perceived fairness of demand-based pricing. In this study, five fences were explored in a restaurant context across three countries (Singapore, Sweden, and the United States). Demand-based pricing in the form of coupons (two for the price of one), time-of-day pricing, and lunch/dinner pricing were perceived as fair. Weekday/weekend pricing was seen as neutral to slightly unfair. Table location pricing was seen as somewhat unfair with potential negative consumer reactions to this practice. Furthermore, framing demand-based pricing as discounts improved perceived fairness. The findings were largely consistent for the three countries. Specifically, framing demand-based pricing as discounts or gains showed no country-specific effect

Perceived Fairness of Revenue Management in the US Golf Industry

Experience in other industries has shown that revenue management can increase revenue without affecting customer satisfaction. Revenue management, however, is underutilized in the golf industry, as customers are believed to perceive such practices as unacceptable and unfair. This paper explores six revenue management practices that might be suitable in a golf context and examines their perceived fairness. The results show that golfers perceive arrival duration control practices in the form of reservation fees or no-show fees as fair. In addition, it was found that golfers perceive demand-based pricing in the form of coupons (two for the price of one), time-of-day and reduced tee time intervals as fair. Conversely, time-of-booking pricing was perceived as neutral to slightly unfair. Varying price levels were seen as unfair, with potential negative consumer reactions to this practice. Furthermore, the paper explores whether framing demand-based pricing as discounts rather than surcharges would make a difference. It was found that demand-based pricing presented as discounts were generally seen as fairer and therefore less likely to have a negative impact on consumer perceptions and reactions

Designing Dental Student Portfolios to Assess Performance

The purpose of this poster is to share a project developed by Marquette University’s liaisons to the American Dental Education Association’s Commission on Change and Innovation in Dental Education with others interested in learning about the use of portfolios to assess the quality of student performance in dental school. Sample components from the pilot portfolios will be integrated into the poster to provide participants with a view from portfolio design to completion. Portfolios are becoming a more common method of assessing the quality of student performance in health professions education. Portfolios can assist in documenting evidence of specific competencies at the student level and also serve as a longitudinal measure of a student’s development

How Long Should Dinner Take? Measuring Expected Meal Duration for Restaurant Revenue Management

Restaurants have two strategic levers for revenue management: duration control and demand-based pricing. Reducing dining times, especially during peak periods, can add considerable revenue for the restaurant. Managing meal duration, however, can be far more complex than manipulating the price. This paper examines dinner duration expectations for a casual restaurant using an adaptation of a price sensitivity measurement tool, naming it \u27Time Sensitivity Measurement\u27 or TSM. TSM is then used to derive the expected dining time, the optimal and indifference duration points. The results show that there is a relatively wide spread of acceptable dining duration times. Furthermore, the optimal and indifference points were significantly shorter than the mean expected dining time, suggesting that many restaurants may be able to shorten dining duration significantly (some 20 per cent in this present study) without compromising customer satisfaction. Furthermore, the paper explores whether demographic variables have an impact on time preferences and finds only nationality effects to be significant. Specifically, North Americans and Asians have similar duration expectations, while Europeans preferred a significantly longer dining time

A retrospective analysis of controlled active motion (CAM) versus modified Kleinert/Duran (modKD) rehabilitation protocol in flexor tendon repair (zones I and II) in a single center.

INTRODUCTION The aim of this study was to analyze primary flexor tendon repair results in zones I and II, comparing the rupture rate and clinical outcomes of the controlled active motion (CAM) protocol with the modified Kleinert/Duran (mKD) protocol. MATERIALS AND METHODS Patients who underwent surgery with traumatic flexor tendon lacerations in zones I and II were divided in three groups according to the type of rehabilitation protocol and period of management: group 1 included patients who underwent CAM rehabilitation protocol with six-strand Lim and Tsai suture after May 2014. Group 2 and 3 included patients treated by six-strand Lim Tsai suture followed by a modified Kleinert/Duran (modK/D) protocol with additional place and hold exercises between 2003 and 2005 (group 2) and between 2011 and 2013 (group 3). RESULTS Rupture rate was 4.7% at 12 weeks in group 1 (3/63 flexor tendon repairs) compared to 2% (1/51 flexor tendon repairs) in group 2 and 8% in group 3 (7/86 flexor tendon repairs). The grip strength at 12 weeks was significantly better in group 2 compared to the group 1 (35 kg/25 kg, p = 0.006). The TAM in group 1 [113° (30-175°)] was significantly worse (p < 0.001) than the TAM in group 2 [141° (90-195°)] but with similar extension deficits in both groups. The assessment of range of motion by the original Strickland classification system resulted in 20% excellent and 15% good outcomes in the CAM group 1 compared with 42% and 36% in the modK/D group 2. Subanalysis demonstrated improvement of good/excellent results according to Strickland from 45% at 3 months to 63.6% after 6-month follow-up in the CAM group. CONCLUSION The gut feeling that lead to change in our rehabilitation protocol could be explained by the heterogenous bias. A precise outcome analysis of group 1 could underline that in patients with complex hand trauma, nerve reconstruction, oedema or early extension deficit, an even more intensive and individual rehabilitation has to be performed to achieve better TAM at 6 or 12 weeks. Our study explicitly demonstrated a significant better outcome in the modK/D group compared to CAM group. This monocenter study is limited by its retrospective nature and the low number of patients

Evaluating RNAlater® as a preservative for using near-infrared spectroscopy to predict Anopheles gambiae age and species.

Mosquito age and species identification is a crucial determinant of the efficacy of vector control programmes. Near-infrared spectroscopy (NIRS) has previously been applied successfully to rapidly, non-destructively, and simultaneously determine the age and species of freshly anesthetized African malaria vectors from the Anopheles gambiae s.l. species complex: An. gambiae s. s. and Anopheles arabiensis. However, this has only been achieved on freshly-collected specimens and future applications will require samples to be preserved between field collections and scanning by NIRS. In this study, a sample preservation method (RNAlater(®)) was evaluated for mosquito age and species identification by NIRS against scans of fresh samples. Two strains of An. gambiae s.s. (CDC and G3) and two strains of An. arabiensis (Dongola, KGB) were reared in the laboratory while the third strain of An. arabiensis (Ifakara) was reared in a semi-field system. All mosquitoes were scanned when fresh and rescanned after preservation in RNAlater(®) for several weeks. Age and species identification was determined using a cross-validation. The mean accuracy obtained for predicting the age of young (<7 days) or old (≥ 7 days) of all fresh (n = 633) and all preserved (n = 691) mosquito samples using the cross-validation technique was 83% and 90%, respectively. For species identification, accuracies were 82% for fresh against 80% for RNAlater(®) preserved. For both analyses, preserving mosquitoes in RNAlater(®) was associated with a highly significant reduction in the likelihood of a misclassification of mosquitoes as young or old using NIRS. Important to note is that the costs for preserving mosquito specimens with RNAlater(®) ranges from 3-13 cents per insect depending on the size of the tube used and the number of specimens pooled in one tube. RNAlater(®) can be used to preserve mosquitoes for subsequent scanning and analysis by NIRS to determine their age and species with minimal costs and with accuracy similar to that achieved from fresh insects. Cold storage availability allows samples to be stored longer than a week after field collection. Further study to develop robust calibrations applicable to other strains from diverse ecological settings is recommended

Revenue Management: Resolving Potential Customer Conflicts

Revenue management is a sophisticated form of supply and demand management that helps a firm maximize revenue by balancing pricing and inventory controls. In recent years, an increasing number of firms have recognized the importance of revenue management in their ability to increase sales and profitability. When a firm that is fundamentally customer oriented also embraces revenue management, however, a series of customer conflicts can result and be detrimental to the firm\u27s long-term success. This paper outlines these potential conflicts and explores various marketing and organizational strategies that can be used to resolve such conflicts