Cloud microphysics and aerosol indirect effects in the global climate model ECHAM5-HAM

The double-moment cloud microphysics scheme from ECHAM4 has been coupled to the size-resolved aerosol scheme ECHAM5-HAM. ECHAM5-HAM predicts the aerosol mass and number concentrations and the aerosol mixing state. This results in a much better agreement with observed vertical profiles of the black carbon and aerosol mass mixing ratios than with the previous version ECHAM4, where only the different aerosol mass mixing ratios were predicted. Also, the simulated liquid, ice and total water content and the cloud droplet and ice crystal number concentrations as a function of temperature in stratiform mixed-phase clouds between 0 and –35°C agree much better with aircraft observations in the ECHAM5 simulations. ECHAM5 performs better because more realistic aerosol concentrations are available for cloud droplet nucleation and because the Bergeron-Findeisen process is parameterized as being more efficient. The total anthropogenic aerosol effect includes the direct, semi-direct and indirect effects and is defined as the difference in the top-of-the-atmosphere net radiation between present-day and pre-industrial times. It amounts to –1.8 W m^−2 in ECHAM5, when a relative humidity dependent cloud cover scheme and present-day aerosol emissions representative for the year 2000 are used. It is larger when either a statistical cloud cover scheme or a different aerosol emission inventory are employed

Terahertz dynamics of a topologically protected state: quantum Hall effect plateaus near cyclotron resonance in a GaAs/AlGaAs heterojunction

We measure the Hall conductivity of a two-dimensional electron gas formed at a GaAs/AlGaAs heterojunction in the terahertz regime close to the cyclotron resonance frequency by employing a highly sensitive Faraday rotation method coupled with electrical gating of the sample to change the electron density. We observe clear plateau-and step-like features in the Faraday rotation angle vs. electron density and magnetic field (Landau-level filling factor), which are the high frequency manifestation of quantum Hall plateaus - a signature of topologically protected edge states. The results are compared to a recent dynamical scaling theory.Comment: 18 pages, 3 figure

Cooling of radiative quantum-dot excitons by terahertz radiation: A spin-resolved Monte Carlo carrier dynamics model

We have developed a theoretical model to analyze the anomalous cooling of radiative quantum dot (QD) excitons by THz radiation reported by Yusa et al [Proc. 24th ICPS, 1083 (1998)]. We have made three-dimensional (3D) modeling of the strain and the piezoelectric field and calculated the 3D density of states of strain induced quantum dots. On the basis of this analysis we have developed a spin dependent Monte Carlo model, which describes the carrier dynamics in QD's when the intraband relaxation is modulated by THz radiation. We show that THz radiation causes resonance transfer of holes from dark to radiative states in strain-induced QD's. The transition includes a spatial transfer of holes from the piezoelectric potential mimima to the deformation potential minimum. This phenomenon strongly enhances the QD ground state luminescence at the expense of the luminescence from higher states. Our model also reproduces the delayed flash of QD ground state luminescence, activated by THz radiation even $\sim1$ s after the carrier generation. Our simulations suggest a more general possibility to cool the radiative exciton subsystem in optoelectronic devices.Comment: 18 pages, 1 table, 8 figures, submitted to Physical Review B v2: major conceptual changes. The article was extended considerably to suit Physical Review B (instead of Physical Review Letters

Knowledge Areas Necessary for Successful NCAA Division III Certified Athletic Trainers: NCAA Division III Certified Athletic Trainers’ Perceptions

NCAA Division III head certified athletic trainers (ATCs) (n=185) were surveyed to determine knowledge areas needed by ATCs to be successful as Division III ATCs. A Likert-like scale survey consisted of 12 athletic training related knowledge areas and included the following five point scale: essential, very important, important, not very important, and irrelevant. Findings indicated that it is important that Division III ATCs have all 12 knowledge areas to be successful. Although injury-related knowledge areas were considered essential, all of the knowledge areas were at least considered important to the success of ATCs, and none were considered irrelevant. Those involved in athletic training curricular issues should place or continue to place the most emphasis on areas related to injuries

Desirable Qualities, Attributes, and Characteristics of Successful Athletic Trainers -- A National Study

In an effort to determine the importance of desirable qualities, attributes and characteristics necessary for the success of interscholastic athletic trainers a Likert-type scale survey was mailed to all head athletic trainers of NCAA Division III institutions in the United States. The survey consisted of 24 statements allowing for the following responses: essential, very important, important, not very important, and irrelevant. The qualities that were deemed the most desirable by head athletic trainers were trustworthiness (76.2%), honesty (73.5%), dependability (66.4%), and possessing high ethical standards (66.4%). The two characteristics that were found to be the least essential were being a risk-taker (2.1%) and being a visionary (6.4%

When do parties put Europe in the centre? Evidence from the 2019 European Parliament election campaign

European elections have been described as second-order phenomena for voters, the media, but also parties. Yet, since 2009, there exists evidence that not only voters, but also political parties assign increasing significance to European elections. While initially 'issue entrepreneurs' were held responsible for this development, the latest campaigns have raised the question of whether mainstream parties are finally also campaigning on European issues. In this article, we examine European Union (EU) salience in the 2019 European Parliament (EP) campaigns of government and opposition parties and the predictors of their strategic behaviours. We test the relevance of factors derived from the selective emphasis and the co-orientation approach within an integrated model of strategic campaign communication based on expert evaluations of 191 parties in 28 EU member states. Results show that the traditional expectation that government parties silence EU issues does not hold anymore; instead, the average EU salience of government and opposition parties is similar on the national level. The strongest predictors for a party's decision to campaign on EU issues are the co-orientation towards the campaign agendas of competing parties, and party's EU position

Constraining uncertainty in aerosol direct forcing

The uncertainty in present-day anthropogenic forcing is dominated by uncertainty in the strength of the contribution from aerosol. Much of the uncertainty in the direct aerosol forcing can be attributed to uncertainty in the anthropogenic fraction of aerosol in the present-day atmosphere, due to a lack of historical observations. Here we present a robust relationship between total present-day aerosol optical depth and the anthropogenic contribution across three multi-model ensembles and a large single-model perturbed parameter ensemble. Using observations of aerosol optical depth, we determine a reduced likely range of the anthropogenic component and hence a reduced uncertainty in the direct forcing of aerosol

Title IX Compliance in NCAA Athletic Departments: Perceptions of Senior Woman Administrators

Perceptions of Senior Woman Administrators (SWAs) were sought regarding the equal provision of 13 Title IX compliance areas in women’s athletic programs as compared to men’s. A five point agree/disagree Likert‐scale survey was electronically mailed to all SWAs at National Collegiate Athletic Association (NCAA) membership institutions throughout the United States. Of the 841 surveys mailed, 406 were returned for a 48.3% return rate. The SWAs disagreed or strongly disagreed at the highest rates that the following five Title IX compliance areas were being provided for equally in the women’s programs when compared to the men’s: publicity (31.0%), locker room facilities (27.1%), coaching (20.0%), recruitment of student‐athletes (15.4%), and equipment and supplies (14.7%). Significant differences between Likert‐scale items of agreement/disagreement were found among the following SWA demographics: marital status, NCAA Division, years of experience, and reporting structure. The SWAs agreed or strongly agreed that the 13 Title IX compliance areas were being provided for equally in the women’s programs when compared to the men’s at the following rates: housing & dining facilities (84.4%), medical & training facilities (84.3%), scheduling of games (81.1%), travel & per diem allowances (80.5%), practice facilities (78.7%), competitive facilities (78.4%), equipment and supplies (77.7%), support services (76.0%), tutoring (74.3%), recruitment of student‐athletes (73.2%), coaching (70.3%), locker room facilities (63.2%), and publicity (55.3%)

Equity and Discrimination in NCAA athletic Departments: Perceptions of Senior Women Administrators

Perceptions of Senior Woman Administrators (SWAs) were sought regarding areas of equity and discrimination in NCAA Athletic Departments. A five point agree/disagree Likert-scale survey was electronically mailed to all NCAA Senior Woman Administrators (SWAs) throughout the United States. Of the 841 surveys mailed, 406 were returned for a 48.3% return rate. To determine differences in the distribution of Likert-scale questions by demographic variable the Kruskal-Wallis rank test was used at a 0.05 nominal significance level. Significant differences with regards to Likert-scale items of agreement/disagreement were found between the following SWA demographics: marital status, reporting structure, and highest level of education completed. Significant differences between demographic variables were noted for eight of the twelve areas of equity and discrimination. Overall, the top three discrimination factors were: family responsibilities disadvantage women more than men, women are paid less than men for comparable positions, and it is more difficult for women to advance than men