Topological Defects Coupling Smectic Modulations to Intra-unit-cell Nematicity in Cuprate

We study the coexisting smectic modulations and intra-unit-cell nematicity in the pseudogap states of underdoped Bi2Sr2CaCu2O8+{\delta}. By visualizing their spatial components separately, we identified 2\pi topological defects throughout the phase-fluctuating smectic states. Imaging the locations of large numbers of these topological defects simultaneously with the fluctuations in the intra-unit-cell nematicity revealed strong empirical evidence for a coupling between them. From these observations, we propose a Ginzburg-Landau functional describing this coupling and demonstrate how it can explain the coexistence of the smectic and intra-unit-cell broken symmetries and also correctly predict their interplay at the atomic scale. This theoretical perspective can lead to unraveling the complexities of the phase diagram of cuprate high-critical-temperature superconductors

Commensurate 4a04a_0 period Charge Density Modulations throughout the Bi2Sr2CaCu2O8+xBi_2Sr_2CaCu_2O_{8+x} Pseudogap Regime

Theories based upon strong real space (r-space) electron electron interactions have long predicted that unidirectional charge density modulations (CDM) with four unit cell (4$a_0$) periodicity should occur in the hole doped cuprate Mott insulator (MI). Experimentally, however, increasing the hole density p is reported to cause the conventionally defined wavevector $Q_A$ of the CDM to evolve continuously as if driven primarily by momentum space (k-space) effects. Here we introduce phase resolved electronic structure visualization for determination of the cuprate CDM wavevector. Remarkably, this new technique reveals a virtually doping independent locking of the local CDM wavevector at $|Q_0|=2\pi/4a_0$ throughout the underdoped phase diagram of the canonical cuprate $Bi_2Sr_2CaCu_2O_8$. These observations have significant fundamental consequences because they are orthogonal to a k-space (Fermi surface) based picture of the cuprate CDM but are consistent with strong coupling r-space based theories. Our findings imply that it is the latter that provide the intrinsic organizational principle for the cuprate CDM state

The JCMT Transient Survey: An Extraordinary Submillimetre Flare in the T Tauri Binary System JW 566

The binary T Tauri system JW 566 in the Orion Molecular Cloud underwent an energetic, short-lived flare observed at submillimetre wavelengths by the SCUBA-2 instrument on 26 November 2016 (UT). The emission faded by nearly 50% during the 31 minute integration. The simultaneous source fluxes averaged over the observation are 500 +/- 107 mJy/beam at 450 microns and 466 +/- 47 mJy/beam at 850 microns. The 850 micron flux corresponds to a radio luminosity of $L_{\nu}=8\times10^{19}$ erg/s/Hz, approximately one order of magnitude brighter (in terms of $\nu L_{\nu}$) than that of a flare of the young star GMR-A, detected in Orion in 2003 at 3mm. The event may be the most luminous known flare associated with a young stellar object and is also the first coronal flare discovered at sub-mm wavelengths. The spectral index between 450 microns and 850 microns of $\alpha = 0.11$ is broadly consistent with non-thermal emission. The brightness temperature was in excess of $6\times10^{4}$ K. We interpret this event to be a magnetic reconnection that energised charged particles to emit gyrosynchrotron/synchrotron radiation.Comment: Accepted in ApJ. 16 pages (single column), 6 figure

Feeding a Brown Midrib Corn Silage-Based Diet to Growing Beef Steers Improves Growth Performance and Economic Returns

A feedlot experiment was performed to determine growth performance, ruminal fermentation characteristics, and economic returns for growing beef steers when fed a brown midrib corn silage-based total mixed ration (BMRT) compared with a conventional corn silage-based total mixed ration (CCST). Twenty-four Angus crossbred steers (initial body weight=258±23.2 kg) in individual pens were used in a completely randomized design (n=12). Intake of dry matter was not different between the treatments. Steers fed the BMRT tended to have greater average daily gain (1.54 vs. 1.42 kg d−1; P=0.09) and gain-to-feed ratio (0.165 vs. 0.146; P=0.07) compared with those fed the CCST. Feeding the BMRT increased total volatile fatty acid (VFA) concentration (P=0.01) compared with the CCST, while it decreased molar proportion of acetate (P\u3c0.01), and increased propionate proportion (P=0.01), resulting in decreased acetate-to-propionate ratio compared with the CCST (P\u3c0.01). Steers fed the BMRT increased feed margin (P=0.05) and net return (P=0.02) compared with those fed the CCST throughout the trial. Overall results of this study indicate that feeding the BMRT to growing beef steers enhanced ruminal fermentation and beneficially shifted VFA profiles, which contributed to improved growth and economic performance of steers © 2015, Agricultural Institute of Canada. All Rights Reserved

The JCMT Transient Survey: An Extraordinary Submillimeter Flare in the T Tauri Binary System JW 566

© 2019 The American Astronomical Society. All rights reserved.The binary T Tauri system JW 566 in the Orion Molecular Cloud underwent an energetic, short-lived flare observed at submillimetre wavelengths by the SCUBA-2 instrument on 26 November 2016 (UT). The emission faded by nearly 50% during the 31 minute integration. The simultaneous source fluxes averaged over the observation are 500 +/- 107 mJy/beam at 450 microns and 466 +/- 47 mJy/beam at 850 microns. The 850 micron flux corresponds to a radio luminosity of $L_{\nu}=8\times10^{19}$ erg/s/Hz, approximately one order of magnitude brighter (in terms of $\nu L_{\nu}$) than that of a flare of the young star GMR-A, detected in Orion in 2003 at 3mm. The event may be the most luminous known flare associated with a young stellar object and is also the first coronal flare discovered at sub-mm wavelengths. The spectral index between 450 microns and 850 microns of $\alpha = 0.11$ is broadly consistent with non-thermal emission. The brightness temperature was in excess of $6\times10^{4}$ K. We interpret this event to be a magnetic reconnection that energised charged particles to emit gyrosynchrotron/synchrotron radiation.Peer reviewedFinal Published versio

Preparing to teach your first class online in Zoom

This useful one-pager lays out the technology basics needed to teach in Zoom. It answers the questions: What do I need? What else should I have? What should I do to prepare

Trauma-Informed Teaching and Learning Online: Principles & Practices During a Global Health Crisis

This is a one-page overview of trauma-informed teaching and learning principles and practices to support educators during a global health crisis. This was created to help those educators who are managing the quick move to online teaching during the COVID-19 pandemic

Recruiting, Training, and Engaging Virtual Faculty via an Award-Winning Online Pedagogy Institute -- #NSWM30

Columbia University School of Social Work’s (CSSW) five-week Institute on Pedagogy and Technology for Online Courses prepares social work professionals to become excellent educators with our Online Campus, which offers a fully online MSW degree. 152 participants from 31 US states have passed in the first four cohorts, and they have led about 100 online courses so far. The award-winning Online Pedagogy Institute includes weekly live virtual class sessions and homework each week in our learning management system, and now offers CEUs. This session will share the details of this innovative training institute and the impact on talent management. The Online Pedagogy Institute is for social workers who want to explore pedagogy and technology for online courses and trains social work professionals to become excellent educators with CSSW’s Online Campus. The institute is designed to be highly engaging, with homework that includes relevant readings, realistic scenarios, quizzes and flashcards to reinforce learning, and weekly live virtual class sessions and discussion forums that build community and enable participants to share their thoughts and expertise. Participants learn how to establish a virtual classroom environment that is welcoming and reflective of social work values, and plan interactive and engaging lessons for an Adobe Connect virtual classroom using web conferencing tools. Participants see the Instructor and Teaching Associate roles modeled, and think about ways they can develop their online teaching skills and personas at a high level of quality. The institute was recognized with an 2018 International E-Learning Award from the International E-Learning Association and a 2019 International Distance Learning Award from the United States Distance Learning Association. The institute attracts a variety of social workers from across the country, creating a diverse and supportive community of professionals who care about providing the next generation of social workers with a high quality education. When the institute concludes, the top participants are recruited for positions as instructors and TAs. As a case study, the institute has high ratings on feedback surveys from graduates. When asked “On a scale of one to ten, how would you rate the overall quality of this Institute?” the average score from our last two cohorts was 9.72. Comments from graduates have included, “The Institute set a golden standard for online education. The live sessions, along with the assignments, modeled holistic learning opportunities and effective teaching strategies. It was incredibly well-rounded and of high quality!” Further, social justice, diversity, and inclusion themes are interwoven throughout the institute’s curriculum in line with social work values. Discussions are held on Universal Design for Learning to support accessibility for all learners and how to address current events, including those impacting social justice. The institute focuses on teaching and modeling pedagogy that is inclusive and accounts for diverse experiences, including have a range of diverse guest faculty discuss their innovative approaches to teaching online