Chatbot responses suggest that hypothetical biology questions are harder than realistic ones

The biology education literature includes compelling assertions that unfamiliar problems are especially useful for revealing students' true understanding of biology. However, there is only limited evidence that such novel problems have different cognitive requirements than more familiar problems. Here, we sought additional evidence by using chatbots based on large language models as models of biology students. For human physiology and cell biology, we developed sets of realistic and hypothetical problems matched to the same lesson learning objectives (LLOs). Problems were considered hypothetical if (i) known biological entities (molecules and organs) were given atypical or counterfactual properties (redefinition) or (ii) fictitious biological entities were introduced (invention). Several chatbots scored significantly worse on hypothetical problems than on realistic problems, with scores declining by an average of 13%. Among hypothetical questions, redefinition questions appeared especially difficult, with many chatbots scoring as if guessing randomly. These results suggest that, for a given LLO, hypothetical problems may have different cognitive demands than realistic problems and may more accurately reveal students' ability to apply biology core concepts to diverse contexts. The Test Question Templates (TQT) framework, which explicitly connects LLOs with examples of assessment questions, can help educators generate problems that are challenging (due to their novelty), yet fair (due to their alignment with pre-specified LLOs). Finally, ChatGPT's rapid improvement toward expert-level answers suggests that future educators cannot reasonably expect to ignore or outwit chatbots but must do what we can to make assessments fair and equitable.

Making the case for prophylactic use of betaine to promote brain health in young (15-24 year old) athletes at risk for concussion

Betaine supplementation in the context of human nutrition, athletic performance, and clinical therapy demonstrate that the osmolyte and methyl donor, betaine, is cytoprotective and beneficial to human health. These studies also demonstrate that betaine supplementation in healthy humans is straight-forward with no reported adverse effects. Here, we explore betaine uptake in the central nervous system (CNS) and contribute to evidence that betaine may be uniquely protective to the brain. We specifically describe the therapeutic potential of betaine and explore the potential implications of betaine on inhibition mediated by GABA and glycine neurotransmission. The influence of betaine on neurophysiology complement betaine's role as an osmolyte and metabolite and is consistent with clinical evidence of betaine-mediated improvements to cognitive function (reported in elderly populations) and its anti-convulsant properties. Betaine's therapeutic potential in neurological disorders including epilepsy and neurodegenerative diseases combined with benefits of betaine supplementation on athletic performance support the unique application of betaine as a prophylaxis to concussion. As an example, we identify young athletes (15-24 years old), especially females, for prophylactic betaine supplementation to promote brain health and resilience in a cohort at high risk for concussion and for developing Alzheimer's disease.

Using Test Question Templates to teach physiology core concepts

The past ∼15 years have seen increasing interest in defining disciplinary core concepts. Within the field of physiology, Michael, McFarland, Modell, and colleagues have published studies that defined physiology core concepts and have elaborated many of these as detailed conceptual frameworks. With such helpful definitions now in place, attention is turning to the related issue of how to maximize student understanding of the core concepts by linking these "big ideas" to concrete student-facing resources for active learning and assessment. Our practitioner-based view begins with the recognition that in many if not most undergraduate physiology courses assessment drives learning. We have therefore linked published conceptual frameworks to Test Question Templates (TQTs), whose structure promotes transparent assessments as well as the active learning needed to prepare for such assessments. We provide examples of conceptual framework-linked TQTs for the physiology core concepts of Homeostasis, Flow Down Gradients, the Cell Membrane, and Cell-Cell Communication. We argue that this deployment of TQTs has at least two distinct benefits for the teaching and learning of core concepts. First, documenting the connections between conceptual frameworks and TQTs may clarify coverage and assessment of the core concepts for both instructors and students. Second, misconceptions about core concepts may be directly targeted and dispelled via thoughtful construction, arrangement, and iteration of TQTs. We propose that the TQT framework or similar approaches may be applied fruitfully to any sufficiently articulated physiology core concept for high school, undergraduate, or graduate students.NEW & NOTEWORTHY Our students often focus on the grades they need to advance through academic programs. How can instructors harness this understandable interest in grades to help students gain a true understanding of core concepts? The new framework of Test Question Templates (TQTs) shows promise in linking student priorities like test scores to instructor priorities like core concepts.

Contribution of the frontal eye field to gaze shifts in the head-unrestrained rhesus monkey: neuronal activity

The frontal eye field (FEF) has a strong influence on saccadic eye movements with the head restrained. With the head unrestrained, eye saccades combine with head movements to produce large gaze shifts, and microstimulation of the FEF evokes both eye and head movements. To test whether the dorsomedial FEF provides commands for the entire gaze shift or its separate eye and head components, we recorded extracellular single-unit activity in monkeys trained to make large head-unrestrained gaze shifts. We recorded 80 units active during gaze shifts, and closely examined 26 of these that discharged a burst of action potentials that preceded horizontal gaze movements. These units were movement or visuomovement related and most exhibited open movement fields with respect to amplitude. To reveal the relations of burst parameters to gaze, eye, and/or head movement metrics, we used behavioral dissociations of gaze, eye, and head movements and linear regression analyses. The burst number of spikes (NOS) was strongly correlated with movement amplitude and burst temporal parameters were strongly correlated with movement temporal metrics for eight gaze-related burst neurons and five saccade-related burst neurons. For the remaining 13 neurons, the NOS was strongly correlated with the head movement amplitude, but burst temporal parameters were most strongly correlated with eye movement temporal metrics (head-eye-related burst neurons, HEBNs). These results suggest that FEF units do not encode a command for the unified gaze shift only; instead, different units may carry signals related to the overall gaze shift or its eye and/or head components. Moreover, the HEBNs exhibit bursts whose magnitude and timing may encode a head displacement signal and a signal that influences the timing of the eye saccade, thereby serving as a mechanism for coordinating the eye and head movements of a gaze shift.

Subsidence of uncemented stems in osteoporotic and non-osteoporotic cadaveric femora

The increased use of uncemented stems for hip arthroplasty and of fast-recovery protocols in elderly patients make initial stem stability and resistance to fracture critical factors in osteoporotic bone. In this paper, the subsidence and failure of two uncemented stem designs (M/L Taper and VerSys Fullcoat, Zimmer, Inc, Warsaw, Indiana, USA) in osteoporotic and non-osteoporotic cadaveric femora were compared under simulated walking conditions (axial compression and external rotation). Osteoporotic femora implanted with either stem design failed significantly more frequently than did non-osteoporotic femora. Femora implanted with the M/L stems (seven of ten by 1000 cycles) fractured earlier than did femora implanted with the Fullcoat stem (one of ten by 1000 cycles). The use of early weight-bearing protocols with uncemented stem designs in osteoporotic bone should be approached with caution.

Biomechanical analysis of sacroplasty: does volume or location of cement matter?

BACKGROUND AND PURPOSE

Currently, the effect of the volume of cement used during sacroplasty on the restoration of pelvic strength and stiffness is unknown. The purpose of this study was to measure that effect in a sacral insufficiency fracture model.

MATERIALS AND METHODS

Twenty-five osteoporotic cadaveric pelves were potted, and sacral fractures were produced. Specimens were divided into 4 groups: group 0 + 0 (control), no sacroplasty; group 3 + 0, sacroplasty (posterior approach), 3 mL of a bone cement injected bilaterally into the fracture site at S1; group 3 + 3, sacroplasty (posterior approach), 3 mL of the same cement injected bilaterally into the fracture site at S1 and S2; and group 6 + 3, sacroplasty (posterior approach), 6 mL of the same cement injected bilaterally at S1 and 3 mL injected bilaterally at S2. Cement position and extravasation were documented with CT. Specimens were tested to failure to assess the strength and stiffness after sacroplasty.

RESULTS

There were no significant differences in strength or stiffness restoration between control and treatment groups.

CONCLUSIONS

Sacroplasty does not restore the strength or stiffness of the sacrum in a cadaveric model regardless of the volume or location of cement.

Contribution of the Frontal Eye Field to Gaze Shifts in the Head-Unrestrained Monkey: Effects of Microstimulation

The role of the primate frontal eye field (FEF) has been inferred primarily from experiments investigating saccadic eye movements with the head restrained. Three recent reports investigating head-unrestrained gaze shifts disagree on whether head movements are evoked with FEF stimulation and thus whether the FEF participates in gaze movement commands. We therefore examined the eye, head, and overall gaze movement evoked by low-intensity microstimulation of the low-threshold region of the FEF in two head-unrestrained monkeys. Microstimulation applied at 200 or 350 Hz for 200 ms evoked large gaze shifts with substantial head movement components from most sites in the dorsomedial FEF, but evoked small, predominantly eye-only gaze shifts from ventrolateral sites. The size and direction of gaze and eye movements were strongly affected by the eye position before stimulation. Head movements exhibited little position dependency, but at some sites and initial eye positions, head-only movements were evoked. Stimulus-evoked gaze shifts and their eye and head components resembled those elicited naturally by visual targets. With stimulus train durations >200 ms, the evoked gaze shifts were more likely to be accomplished with a substantial head movement, which often continued for the entire stimulus duration. The amplitude, duration and peak velocity of the evoked head movement were more strongly correlated with stimulus duration than were those of the gaze or eye movements. We conclude that the dorsomedial FEF generates a gaze command signal that can produce eye, head, or combined eye–head movement depending on the initial orbital position of the eye.