Exogenous Glycinebetaine Reduces Cadmium Uptake and Mitigates Cadmium Toxicity in Two Tobacco Genotypes Differing in Cadmium Tolerance.

Greenhouse hydroponic experiments were conducted using Cd-sensitive (cv. Guiyan1) and Cd-tolerant (cv. Yunyan2) tobacco cultivars to study the ameliorative effects of exogenous glycinebetaine (GB) upon 5 µM Cd stress. The foliar spray of GB markedly reduced Cd concentrations in plants and alleviated Cd-induced soil plant analysis development (SPAD) value, plant height and root length inhibition, with the mitigation effect being more obvious in Yunyan2. External GB markedly reduced Cd-induced malondialdehyde (MDA) accumulation, induced stomatal closure, ameliorated Cd-induced damages on leaf/root ultrastructure, and increased the chlorophyll content and fluorescence parameters of Fo, Fm, and Fv/Fm in both cultivars and Pn in Yunyan2. Exogenous GB counteracted Cd-induced alterations of certain antioxidant enzymes and nutrients uptake, e.g., the depressed Cd-induced increase of superoxide dismutase (SOD) and peroxidase (POD) activities, but significantly elevated the depressed catalase (CAT) and ascorbate peroxidase (APX) activities. The results indicate that alleviated Cd toxicity by GB application is related to the reduced Cd uptake and MDA accumulation, balanced nutrients and antioxidant enzyme activities, improved PSII, and integrated ultrastructure in tobacco plants.

Clinical Neuroscience in Practice: An Experiential Learning Course for Undergraduates Offered by Neurosurgeons and Neuroscientists.

Many pre-health students pursue extracurricular shadowing opportunities to gain clinical experience. The Virginia Tech School of Neuroscience introduced a formal course that provides a clinical experience superior to that received by many medical students. This course is composed of weekly 75-minute seminars that cover diseases affecting the nervous system, their diagnosis and treatment, complemented by weekly half-day intensive clinical experiences with unprecedented access to a team of neurosurgeons (in hospital operating rooms, Intensive Care Units, emergency room, angiographic suites, and wards). In the operating rooms, students routinely "scrub-in" for complex surgeries. On hospital rounds, students experience direct patient care and receive in-depth exposure to modern nervous system imaging. Students participate in two 24-hour "on-call" experiences with team providers. After call, students participate in cognitive and psychological studies to assess physiological and psychological effects of call-related sleep deprivation. Students prepare weekly essays on challenging socioeconomic and ethical questions, exploring subjects such as the cost of medicine and inequalities in access to health care. Towards the end of the course, students meet with the admission dean of the Virginia Tech Carilion medical school; they prepare a personal statement for medical school/graduate school applications, and attend a half-day block of mock medical school/graduate school interviews delivered by experienced clinicians. In lieu of a final exam, each student presents to the entire neurosurgery department, an in-depth clinical analysis of a case in which they participated. We provide details on implementation, challenges and outcomes based on experiences from three semesters with a total enrollment of approximately 60 students.