COVID-19 and the Transition to Online Learning in the Basic Course: Examining Effects on Student Learning

Objectives: This study examines how the transition to remote delivery during the spring of 2020 affected student learning in the basic communication course. Methods: Participants in three different course delivery modes (face-to-face, online, and live interactive) were enrolled in a public speaking course with standardized adaptive reading quizzes, exams, and speech assignments. Participants completed several measures over the course of the semester and had their responses paired up with their end-of-semester grade book data. Results: Results of this study indicate that students who were enrolled in a face-to-face course and transitioned online during the COVID-19 pandemic were outperformed by online and learning interactive students in several of the standardized assignments in the course. Conclusions: Overall, face-to-face (FtF) students performed four percentage points lower in the course than the learning interactive and online groups while also demonstrating more emotional interest in the course than the other two groups. Implication for Theory and/or Practice: In future transitions to remote learning, FtF students may experience greater disruption than existing online students. Instructors should be mindful of this finding in transitioning to remote learning during the semester

Investigations on the individual and maternal components of calving performance in cattle

International audienc

Einsatz einer Extrapolationsmethode bei der Versagensanalyse thermozyklisch beanspruchter Bauteile

  &nbsp

Datos preliminares de las inclusiones fluidas (petróleo y acuosas) en las fracturas cementadas de las Fms. Corones y Armàncies, Eoceno, Pirineo oriental

Las calizas del Eoceno del Pirineo sur-oriental están afectadas por fracturas con direcciones N-NE, buzamientos subverticales (55-72º), espesores centimétricos y longitudes de varios metros. En ocasiones también se observan cavidades vacuolares. Tanto las fracturas como las cavidades vacuolares están rellenas por cementos carbonáticos que no ocluyen totalmente la porosidad. Además, la presencia de indicios de petróleo es muy abundante en las fracturas que afectan a la parte alta de la Fm Armàncies (Cuisiense, Eoceno) y son menos abundantes, pero están también presentes, en la Fm Corones (Cuisiense inferior). El objetivo principal de este trabajo es caracterizar los tipos de inclusiones fluidas (IF) en los cementos carbonáticos que rellenan fracturas como primera aproximación a la historia de migración del petróleo. El estudio detallado de petrografía, fluorescencia y microtermometría ha revelado que en la Fm Corones aparecen tres tipos de inclusiones con dos fases (líquido y vapor): i) IF de petróleo con fluorescencia amarilla; ii) IF de petróleo con fluorescencia amarilla y color marrón en luz transmitida; ambos tipos de IF aparecen como trazas de pequeña longitud que afectan sólo a uno o dos cristales de calcita, lo cual sugiere un origen secundario; iii) IF acuosas de tamaños muy pequeño (5-10 μm) que aparecen en los bordes de los cristales indicando un origen primario. En la Fm Armàncies aparecen cuatro tipos de inclusiones con dos fases (líquido y vapor): i) IF de petróleo con fluorescencia amarilla; ii) IF de petróleo con fluorescencia amarilla y color marrón en luz transmitida; iii) IF petróleo con fluorescencia azul y azul intenso, que son las más abundantes; todas las IF de petróleo aparecen como trazas de gran continuidad, paralelas a los márgenes de las fracturas, lo cual sugiere un origen primario; iv) IF acuosas que son muy escasas y aparecen como trazas. En resumen, los datos preliminares del estudio de inclusiones fluidas sugieren que el petróleo en la Fm Armàncies migró a través de fracturas de forma coetánea con la precipitación de los cementos carbonáticos. Por el contrario, el petróleo fue atrapado en el cemento carbonático de las fracturas de la Fm Corones, pero no durante su precipitación, sino posteriorment

From the Feynman-Schwinger representation to the non-perturbative relativistic bound state interaction

We write the 4-point Green function in QCD in the Feynman-Schwinger representation and show that all the dynamical information are contained in the Wilson loop average. We work out the QED case in order to obtain the usual Bethe-Salpeter kernel. Finally we discuss the QCD case in the non-perturbative regime giving some insight in the nature of the interaction kernel.Comment: 25 pages, RevTex, 3 figures included, typos corrected, to appear in Phys. Rev. D 5

CD8(+) T cells retain protective functions despite sustained inhibitory receptor expression during Epstein-Barr virus infection in vivo

Epstein Barr virus (EBV) is one of the most ubiquitous human pathogens in the world, persistently infecting more than 90% of the adult human population. It drives some of the strongest human CD8+ T cell responses, which can be observed during symptomatic primary infection known as infectious mononucleosis (IM). Despite high viral loads and prolonged CD8+ T cell stimulation during IM, EBV enters latency and is under lifelong immune control in most individuals that experience this disease. We investigated whether changes in T cell function, as frequently characterized by PD-1 up-regulation, occur during IM due to the prolonged exposure to high antigen levels. We readily detected the expansion of PD-1 positive CD8+ T cells together with high frequencies of Tim-3, 2B4, and KLRG1 expression during IM and in mice with reconstituted human immune system components (huNSG mice) that had been infected with a high dose of EBV. These PD-1 positive CD8+ T cells, however, retained proliferation, cytokine production, and cytotoxic abilities. Multiple subsets of CD8+ T cells expanded during EBV infection, including PD-1+ Tim-3+ KLRG1+ cells that express CXCR5 and TCF-1 germinal center homing and memory markers, and may also contain BATF3. Moreover, blocking the PD-1 axis compromised EBV specific immune control and resulted in virus-associated lymphomagenesis. Finally, PD-1+ , Tim-3+ , and KLRG1+ CD8+ T cell expansion coincided with declining viral loads during low dose EBV infection. These findings suggest that EBV infection primes PD-1 positive CD8+ T cell populations that rely on this receptor axis for the efficient immune control of this ubiquitous human tumor virus