Limits on the infrared photometric monitoring of brown dwarfs

Recent monitoring programs of ultra cool field M and L dwarfs (low mass stars or brown dwarfs) have uncovered low amplitude photometric I-band variations which may be associated with an inhomogeneous distribution of photospheric condensates. Further evidence hints that this distribution may evolve on very short timescales, specifically of order a rotation period or less. In an attempt to study this behaviour in more detail, we have carried out a pilot program to monitor three L dwarfs in the near infrared where these objects are significantly brighter than at shorter wavelengths. We present a robust data analysis method for improving the precision and reliability of infrared photometry. No significant variability was detected in either the J or Km bands in 2M1439 and SDSS1203 above a peak-to-peak amplitude of 0.04 mag (0.08 mag for 2M1112). The main limiting factor in achieving lower detection limits is suspected to be second order extinction effects in the Earth's atmosphere, on account of the very different colours of the target and reference stars. Suggestions are given for overcoming such effects which should improve the sensitivity and reliability of infrared variability searches.Comment: MNRAS, in press (9 pages

WSM Radio Field Strength During August 21, 2017 Eclipse

Field intensity measurements of AM radio station WSM Nashville were recorded at a point 171 miles distant during the 8-21-2017 total eclipse. Both transmitter and receiver were in the path of totality. Dramatic changes in intensity were observed and were likely caused by alterations of the ionospheric D-layer during the eclipse

Higher Education Leadership Development During the COVID-19 Pandemic: An Exploration of Online Learner Readiness

The COVID-19 pandemic precipitated profound disruptions across the higher education sector as institutions were forced to restructure entire systems and operate with significantly reduced resources. Most notably, many institutions were forced to transition to fully virtual instruction. The present study examined adult leadership development program participants’ perceptions of online learning readiness during the transition to a fully virtual training environment precipitated by the COVID-19 pandemic. A census of the 2020 LEAD21 class was taken, and perceptions of online learning readiness were collected via a retrospective pre- and post-test. Descriptive and inferential statistics were used. Respondents had the highest levels of agreement with computer and Internet self-efficacy and the lowest levels of agreement with learner control in an online context. A paired t-test was conducted to analyze the difference in perceptions of online learning readiness post-training and retrospective pre-training. A statistically significant increase was observed for overall online learning readiness, as well as for computer and Internet self-efficacy, learner control, motivation for learning, Internet communication self-efficacy, and self-directed learning. An implication from this finding is that the transition to fully virtual training resulted in increased online learning readiness across all dimensions. With new strains of COVID-19 emerging and the potential for ongoing restrictions for social interaction, online learning will continue to be an important aspect of the educational process. It is vital that higher education leaders consider individuals’ readiness to effectively engage in online training and instruction. Implications and recommendations for future research in practice in international contexts are provided

Existence of immersed spheres minimizing curvature functionals in compact 3-manifolds

We study curvature functionals for immersed 2-spheres in a compact, three-dimensional Riemannian manifold M. Under the assumption that the sectional curvature of M is strictly positive, we prove the existence of a smoothly immersed sphere minimizing the L^{2} integral of the second fundamental form. Assuming instead that the sectional curvature is less than or equal to 2, and that there exists a point in M with scalar curvature bigger than 6, we obtain a smooth 2-sphere minimizing the integral of 1/4|H|^{2} +1, where H is the mean curvature vector

National 4-H Congress: A Retrospective Evaluation

National 4-H Congress is an example of a programmatic effort designed to help youth develop various life skills. For this study, demographic, event satisfaction, and application of knowledge data were collected from 2,154 past Congress participants. Findings revealed that the majority of participants were satisfied or very satisfied with their Congress experience, and 63% of the respondents had used information gained from the event. Continued efforts to ensure future delegations represent the diversity of 4-H are encouraged, along with continued evaluation of event satisfaction levels and the extent to which life skills are developed and retained

Quantization for an elliptic equation of order 2m with critical exponential non-linearity

On a smoothly bounded domain $\Omega\subset\R{2m}$ we consider a sequence of positive solutions $u_k\stackrel{w}{\rightharpoondown} 0$ in $H^m(\Omega)$ to the equation $(-\Delta)^m u_k=\lambda_k u_k e^{mu_k^2}$ subject to Dirichlet boundary conditions, where $0<\lambda_k\to 0$. Assuming that $$\Lambda:=\lim_{k\to\infty}\int_\Omega u_k(-\Delta)^m u_k dx<\infty,$$ we prove that $\Lambda$ is an integer multiple of \Lambda_1:=(2m-1)!\vol(S^{2m}), the total $Q$-curvature of the standard $2m$-dimensional sphere.Comment: 33 page