Trinity University

The Amazonian freshwater stingray Potamotrygon wallacei, endemic to the Rio Negro basin, although heavily exploited in ornamental fish trade, is largely neglected in terms of basic biology, including its reproductive system. Polyandry is a widespread reproductive strategy in elasmobranchs, however, evidence from freshwater potamotrygonids is scarce. To address this knowledge gap, the present study developed highly polymorphic single nucleotide polymorphism (SNP) genomic markers for P. wallacei and applied them to investigate kinship patterns in wild-caught gravid females and their litters. This study used genomic polymorphic SNP markers in 18 individuals from five family groups to assess kinship patterns. The average gene diversity was low, however, He (0.435–0.476) and Ho (0.530–0.653) were higher, with Ho > He, suggesting small-sample bias or heterozygote excess from family-level sampling. Polyandry was detected in three families, while two families exhibited monogamy. This molecular approach allowed the discovery of polyandry in P. wallacei, providing novel insights into its reproductive biology and contributing to broader understanding of mating system evolution in Neotropical freshwater elasmobranchs.

This cross-sectional study uses a mystery caller approach to identify the level of acceptance of new pediatric patients and the length of waiting for a first appointment at general and pediatric dermatology practices.

Copolymerization is a powerful tool for tuning the properties of synthetic polymers. In chain-growth polymerization, copolymer microstructure is controlled by the relative reactivity of comonomers, quantified by copolymer reactivity ratios. Yet, the complex macromolecular reactivity captured by reactivity ratios precludes the prediction of the resultant microstructures by intuition, and the established theory to understand reactivity ratios (i.e., Q-e scheme) has not been updated substantially since the development of quantum mechanics. Here, we combine modern computation, data science, and experimental validation to gain a detailed structure–reactivity understanding of the electronic, energetic, and steric parameters that govern comonomer reactivity. Using >450 reactivity ratios identified from primary literature sources, a combination of parametrization from density functional theory and data science methods identified discrete structure–reactivity relationships in free radical copolymerization. We demonstrate that the electronics of the radical species and the sterics of the monomers, neither of which were captured in the previous Q-e scheme, are pivotal to understanding the copolymerization reactivity. Experimentally measured reactivity ratios of a previously unstudied monomer combination validated the models, demonstrating the potential predictive power of this work to understand the comonomer sequence a priori. This work provides a framework to understand polymer microstructure from first-principles by relating specific and interpretable attributes of monomer structure to comonomer reactivity.

ABSTRACT Research methods With the aim of capturing the experience of serving as citizen sport diplomats and making sense of it to inform future practice, this research utilized a collaborative self-ethnography approach. This reflexive approach brings together: (a) analytic autoethnography as individuals themselves are engaged in the ethnography and study, and (b) collective ethnography as a team collects and makes sense of shared data regarding the same context and phenomena. Results and findings During the outbound exchange, we each created journal entries about our experiences, followed by daily discussion of entries, and highlighting possible emerging themes. This process was repeated nine times. The discussions were recorded and transcribed and we used a reflexive thematic approach to uncover the first three teams of Odyssey, Border Straddling, and Throwing Seeds/Planting Rows. Representative quotes for Brush Sets, the fourth theme, were identified using a deductive thematic analysis approach. Implications Our findings revealed the need for future research to understand how planning, preparation, and resource allocation impacts the long-term success and sustainability of sport diplomacy exchanges. From a practical standpoint, each theme provides a framework for the required mental and physical resources of a sport diplomatic exchange and highlights that deep levels of transformational learning can occur during these programs.

We developed a unified analytical framework for the global dynamics of discrete-time susceptible infectious susceptible (SIS) epidemic models with nonlinear recruitment. Emphasis was placed on demographic feedback through Beverton-Holt and Ricker-type recruitment, which regulates host population size and thereby shapes transmission and long-term persistence (Persistence allows population densities to approach zero asymptotically, wheras uniform persistence requires them to remain bounded away from zero). Under minimal assumptions, we reduced non-autonomous systems to appropriately defined autonomous limiting systems and used this reduction to obtain a complete global threshold characterization: When the basic reproduction number $ R_{0} > 1 $, the endemic equilibrium existed and was globally asymptotically stable; when $ R_{0}\le 1 $, solutions converged to the disease-free state. The approach extended to periodically forced SIS models, which showed that the threshold and stability conclusions persisted in the periodic non-autonomous setting. The results unified and strengthened prior work and clarify how recruitment dynamics govern persistence in discrete-time epidemic systems.

Some prior studies of item recognition, source recognition, and judgments of learning have produced evidence of framing effects in episodic memory. A theoretical consequence of these phenomena is that emotional arousal is not a necessary condition for framing effects because, unlike the classic framing effects of social psychology and behavioral economics, different memory frames are not designed to stimulate different emotional reactions. However, a review of available evidence on framing effects in item recognition revealed that the data were inconsistent for old items and nonexistent for similar distractors. We attempted to secure definitive evidence of whether these types of items display framing effects by analyzing a corpus of 478 sets of data, in which old items and similar distractors are factorially crossed with old? and similar? recognition frames. Both types of items exhibited large framing effects: Recognition was far more accurate for similar items than for old items when probes asked if test items were old, whereas recognition was more accurate for old items than for similar items when probes asked if test items were similar. There was a frame-independence effect, too, such that accuracy in one memory frame was dissociated from accuracy in the other frame. The conjoint-recognition model predicted both the core memory framing effect and its direction (superior recognition of similar distractors in the old? frame but superior recognition of old items in the similar? frame). The model also explained frame independence as a by-product of between-frame differences in how three retrieval processes (true recollection, false recollection, and semantic familiarity) affect accuracy in the different frames. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

ABSTRACT As Generative Artificial Intelligence (GenAI) tools become more prevalent in education, understanding their impact on student learning, satisfaction, and self-efficacy is critical. This study examines how students’ perceptions of GenAI influence their satisfaction with instructors and their academic self-efficacy in fully asynchronous/hybrid online upper-level marketing courses. Using survey data from three online courses at a southeastern public university, we assess whether ChatGPT, a widely used GenAI, serves as a beneficial tool in self-directed learning environments. Our findings indicate that students with positive perceptions of ChatGPT report higher satisfaction with their instructor, which in turn enhances their self-efficacy. However, this effect is contingent on students’ perceived learning, with those who perceive lower learning gains benefiting the most from ChatGPT usage. These results suggest that while GenAI tools such as ChatGPT can support students in online courses, their impact is not uniform across all learners. Our research contributes to the growing discourse on GenAI in education by providing empirical evidence on its pedagogical implications and offering recommendations for responsible integration. Future research may explore GenAI’s role in diverse learning contexts and assess its long-term influence on student performance.