Effects of Ratemyprofessors.com and University Student Evaluations of Teaching on Students’ Course Decision-Making and Self-Efficacy

This study investigated effects of Ratemyprofessors.com and university student evaluations of teaching on students’ course decision making and self-efficacy in an ethnically diverse undergraduate sample. It also investigated if these effects were impacted by evaluation positivity. Additionally, the study explored if attitudes toward Ratemyprofessors.com was related to student gender, college class, and age. Participants were 73 undergraduates who were exposed to positive and negative evaluations about fictitious professors; participants were informed that the evaluations originated from RMP or university student evaluations of teaching. Evaluation positivity but not type influenced students’ intention to enroll in the professor’s course, but not how seriously they would consider the feedback. Evaluation positivity also influenced self-efficacy. Beliefs about and use of Ratemyprofessors.com were not related to student gender, college class, or age. Implications for student course decision making and self-efficacy for university students, faculty, and administrators are discussed

Nonlinear instability dynamics in a high-density, high-beta plasma

Entrainment and periodic pulling of an ion acoustic instability have been observed in the power spectra of a low-pressure high-beta plasma. The observed nonlinear phenomena can be modeled by using the van der Pol equation with a forcing term. Experimental results of the nonlinear processes are presented. Ion density fluctuations are detected on a negatively biased Langmuir probe for magnetic fields and input powers above 30 G and 900 W at 7.2 MHz respectively, and gas pressure below 1.5 mTorr. This low-frequency instability is observed in the central plasma blue core (argon II emission) and can be controlled by amplitude modulation of the radio frequency input power at frequencies close to the instability frequency

High-beta plasma effects in a low-pressure helicon plasma

In this work, high-beta plasma effects are investigated in a low-pressure helicon plasma source attached to a large volume diffusion chamber. When operating above an input power of 900 W and a magnetic field of 30 G a narrow column of bright blue light due to Ar II radiation is observed along the axis of the diffusion chamber. With this blue mode, the plasma density is axially very uniform in the diffusion chamber; however, the radial profiles are not, suggesting that a large diamagnetic current might be induced. The diamagnetic behavior of the plasma has been investigated by measuring the temporal evolution of the magnetic field Bz and the plasma kinetic pressure when operating in a pulsed discharge mode. It is found that although the electron pressure can exceed the magnetic field pressure by a factor of 2, a complete expulsion of the magnetic field from the plasma interior is not observed. In fact, under our operating conditions with magnetized ions, the maximum diamagnetism observed is 2%. It is observed that the magnetic field displays the strongest change at the plasma centre, which corresponds to the maximum in the plasma kinetic pressure. These results suggest that the magnetic field diffuses into the plasma sufficiently quickly that on a long time scale only a slight perturbation of the magnetic field is ever observed

Quantification of cellular protein expression and molecular features of group 3 LEA proteins from embryos of Artemia franciscana

Late embryogenesis abundant (LEA) proteins are highly hydrophilic, low complexity proteins whose expression has been correlated with desiccation tolerance in anhydrobiotic organisms. Here, we report the identification of three new mitochondrial LEA proteins in anhydrobiotic embryos of Artemia franciscana, AfrLEA3m-47, AfrLEA3m-43, and AfrLEA3m-29. These new isoforms are recognized by antibody raised against recombinant AfrLEA3m, the original mitochondrial-targeted LEA protein previously reported from these embryos; mass spectrometry confirms all four proteins share sequence similarity. The corresponding messenger RNA (mRNA) species for the four proteins are readily amplified from total complementary DNA (cDNA) prepared from embryos. cDNA sequences of the four mRNAs are quite similar, but each has a stretch of sequence that is absent in at least one of the others, plus multiple single base pair differences. We conclude that all four mitochondrial LEA proteins are products of independent genes. Each possesses a mitochondrial targeting sequence, and indeed Western blots performed on extracts of isolated mitochondria clearly detect all four isoforms. Based on mass spectrometry and sodium dodecyl sulfate polyacrylamide gel electrophoresis migration, the cytoplasmic-localized AfrLEA2 exists primarily as a homodimer in A. franciscana. Quantification of protein expression for AfrLEA2, AfrLEA3m, AfrLEA3m-43, and AfrLEA3m-29 as a function of development shows that cellular concentrations are highest in diapause embryos and decrease during development to low levels in desiccation-intolerant nauplius larvae. When adjustment is made for mitochondria matrix volume, the effective concentrations of cytoplasmic versus mitochondrial group 3 LEA proteins are similar in vivo, and the values provide guidance for the design of in vitro functional studies with these proteins. © 2013 Cell Stress Society International