Surfactants are commonly used in foliar applications to enhance interactions of active ingredients with plant leaves. We employed metabolomics to understand the effects of TritonTM X-100 surfactant (SA) and nanomaterials (NMs) on wheat (Triticum aestivum) at the molecular level. Leaves of three-week-old wheat seedlings were exposed to deionized water (DI), surfactant solution (SA), NMs-surfactant suspensions (Cu(OH)2 NMs and MoO3 NMs), and ionic-surfactant solutions (Cu IONs and Mo IONs). Wheat leaves and roots were evaluated via physiological, nutrient distribution, and targeted metabolomics analyses. SA had no impact on plant physiological parameters, however, 30+ dysregulated metabolites and 15+ perturbed metabolomic pathways were identified in wheat leaves and roots. Cu(OH)2 NMs resulted in an accumulation of 649.8 μg/g Cu in leaves; even with minimal Cu translocation, levels of 27 metabolites were significantly changed in roots. Due to the low dissolution of Cu(OH)2 NMs in SA, the low concentration of Cu IONs induced minimal plant response. In contrast, given the substantial dissolution of MoO3 NMs (35.8%), the corresponding high levels of Mo IONs resulted in significant metabolite reprogramming (30+ metabolites dysregulated). Aspartic acid, proline, chlorogenic acid, adenosine, ascorbic acid, phenylalanine, and lysine were significantly upregulated for MoO3 NMs, yet downregulated under Mo IONs condition. Surprisingly, Cu(OH)2 NMs stimulated wheat plant tissues more than MoO3 NMs. The glyoxylate/dicarboxylate metabolism (in leaves) and valine/leucine/isoleucine biosynthesis (in roots) uniquely responded to Cu(OH)2 NMs. Findings from this study provide novel insights on the use of surfactants to enhance the foliar application of nanoagrochemicals.
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Notional Machine in Mathematics and Introductory Computer Science Courses
Notional Machines (NMs) are a pedagogical device used by teachers in order to help students understand certain concepts. While NMs have been cataloged, the effectiveness of NMs has been rarely evaluated. We build upon this research by exploring what makes certain NMs more effective in various computer science and mathematics courses. We interview professors and students to assess NMs used in the classroom. Notably we found that most students are able to employ the NMs introduced by their professors, and that introductory students prefer template-like NMs, whereas upper level students rely on more conceptual NMs.
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- Award ID(s):
- 2049911
- PAR ID:
- 10404382
- Date Published:
- Journal Name:
- SIGCSE 2023: Proceedings of the 54th ACM Technical Symposium on Computer Science Education
- Volume:
- 2
- Page Range / eLocation ID:
- 1379 to 1379
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract The next generations of science, technology, engineering, and math (STEM) workers are being trained in college and university classrooms by a workforce of instructors who learn pedagogical practice largely on the job. While inclusive instructional practices and their impacts are increasingly well-studied, this training is difficult to instill within the professional development that most STEM professors receive before teaching their students. The Science Teaching Experience Program for Upcoming PhDs (STEP-UP) at the University of Washington was built to prepare future professors for inclusive excellence by guiding them through the literature in education research and providing them a space to practice active and inclusive teaching techniques. This study of STEP-UP uses a design-based approach to understand graduate trainee and undergraduate perceptions of the most salient aspects and outcomes of the program. Our study found that trainees used opportunities to practice inclusive teaching methods with a cohort of their peers, and crucially that these methods were evident in trainee-taught courses through multiple lines of evidence. STEP-UP-trained instructors used inclusive teaching strategies that helped students to feel socioemotionally supported. This study offers a model program that fosters inclusion and equity in undergraduate STEM classrooms through improving teaching professional development for graduate students.
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Abstract Single‐crystalline inorganic semiconductor nanomembranes (NMs) have attracted great attention over the last decade, which poses great advantages to complex device integration. Applications in heterogeneous electronics and flexible electronics have been demonstrated with various semiconductor nanomembranes. Single‐crystalline aluminum nitride (AlN), as an ultrawide‐bandgap semiconductor with great potential in applications such as high‐power electronics has not been demonstrated in its NM forms. This very first report demonstrates the creation, transfer‐printing, and characteristics of the high‐quality single‐crystalline AlN NMs. This work successfully transfers the AlN NMs onto various foreign substrates. The crystalline quality of the NMs has been characterized by a broad range of techniques before and after the transfer‐printing and no degradation in crystal quality has been observed. Interestingly, a partial relaxation of the tensile stress has been observed when comparing the original as‐grown AlN epi and the transferred AlN NMs. In addition, the transferred AlN NMs exhibits the presence of piezoelectricity at the nanoscale, as confirmed by piezoelectric force microscopy. This work also comments on the advantages and the challenges of the approach. Potentially, the novel approach opens a viable path for the development of the AlN‐based heterogeneous integration and future novel electronics and optoelectronics.
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Cancer cells have unique but widely varying characteristics that have proven them difficult to be treated by classical therapeutics and calls for novel and selective treatment options. Nanomaterials (NMs) have been shown to display biological effects as a function of their chemical composition, and the extent and exact nature of these effects can vary between different biological environments. Here, ZnO NMs are doped with increasing levels of Fe, which allows to finely tune their dissolution rate resulting in significant differences in their biological behavior on cancer or normal cells. Based on in silico analysis, 2% Fe‐doped ZnO NMs are found to be optimal to cause selective cancer cell death, which is confirmed in both cultured cells and syngeneic tumor models, where they also reduce metastasis formation. These results show that upon tuning NM chemical composition, NMs can be designed as a targeted selective anticancer therapy.
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Abstract Objective Socially constructed ethnic identities are frequently rooted in beliefs about common descent that form when people with disparate cultures, languages, and biology come into contact. This study explores connections between beliefs about common descent, as represented by ethnic nomenclatures, and histories of migration and isolation ascertained from genomic data in New Mexicans of Spanish‐speaking descent (NMS).
Materials and Methods We interviewed 507 NMS who further identified using one of seven ethnic terms that they associated with beliefs about connections to past ancestors. For groups of individuals who identified using each term, we estimated biogeographic ancestry, fit admixture models to ancestry distributions, and partitioned genetic distance into admixture and drift components.
Results Regardless of which ethnic term they used, all NMS had appreciable Native American (avg. 27%) and European ancestry (avg.71%). However, individuals who identified using terms associated with beliefs connecting them to colonial‐period Spanish ancestors had significantly higher European ancestry than individuals who identified using terms associated with ancestral connections to post‐colonial‐period migrants from Mexico. Model‐fitting analyses show that this ancestry difference reflects post‐colonial gene flow with non‐NMS European Americans, not colonial‐period gene flow with Spaniards. Drift, not admixture, accounted for most of the genetic distance between NMS who expressed connections to Mexican versus Spanish ancestors, reflecting relative isolation of New Mexico and Mexico through the 19th century.
Discussion Patterns of genomic diversity in NMS are consistent with beliefs about common descent in showing that New Mexico was isolated for generations following initial colonization. They are inconsistent with these beliefs in showing that all NMS have substantial European and Native American ancestry, and in showing that a proportion of European ancestry derives from post‐colonial‐period admixture with non‐NMS European Americans. Our findings provide insights into the construction of ethnic identity in contexts of migration and isolation in New Mexico and, potentially, throughout human prehistory.
- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1145/3545947.3576324
