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Citrusspp. trees are not fully dormant during the winter months in the northern hemisphere; therefore, they are susceptible to sporadic freeze events of various magnitudes that could decline tree productivity or be lethal. In Feb 2021, winter storm Uri produced freezing air temperatures for nearly 72 hours, which created several degrees of injuries to citrus orchards in southern Texas. Producers in the area implemented combinations of multiple horticultural practices aimed at remediating injuries from the cold spell to stimulate root and tree recovery. However, there is a gap in our understanding of how practices such as compost application (CA) combined with varying rates of nitrogen (N) might facilitate tree recovery. Therefore, we conducted a 2-year field experiment using two CAs as soil amendments in combination with three N rates (112, 168, and 224 kg·ha−1N) to evaluate fruit yield and internal quality, root growth, and recovery of ‘Rio Red’ grapefruits (Citrus×paradisiMacf.) and ‘Marrs’ sweet oranges (Citrus sinensis). The yields of both crops exhibited modest improvement with CA in 2022; however, it was nonsignificant. Moreover, CA elicited more beneficial effects than N rates alone when rehabilitating trees and improving fruit internal quality after freezing events. Grapefruit brix was 4% higher in fruits harvested from trees treated with compost, and grapefruit roots exhibited a two-fold dry weight increment with CA. Sweet oranges from trees in the CA treatment had 22% lower acidity compared with that of untreated trees. Overall, our results indicate that citrus producers in southern Texas and other subtropical citrus-producing regions might facilitate the rehabilitation of tree injuries attributed to mild to moderate freeze events with moderate financial gains with the timely application of compost, which enhanced tree fitness and ameliorated fruit productivity declines during subsequent harvests.more » « lessFree, publicly-accessible full text available December 1, 2025
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Murphy, B.; Roberts, K. (Ed.)In the summer of 2020, NSTA received the exciting news that it had received a grant from the National Science Foundation to engage in a project to help advance the field of connected STEM learning. The goal of this project was to publish resources in Connected Science Learning (CSL) that would support STEM educators in applying the latest research to the design and delivery of connected STEM learning experiences. This ebook is a culmination of this work.more » « less
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Teaming is a core part of engineering education, especially in the first and last years of engineering when project work is a prevalent focus. The literature on the effects of working in diverse teams is mixed. Negative findings include decreased affect, increased frustration, and sustained conflict in teams. Positive findings include increased productivity, production of high quality products, and divergent-thinking and idea generation. Given these mixed findings, it becomes important to not only understand the practical outputs of working in diverse teams, but also how the experience of working in diverse teams influences whether students see themselves as engineers and whether or not they feel they belong in engineering. Our project, Building Supports for Diversity through Engineering Teams, investigates how students’ attitudes towards diversity influence how students experience work in diverse teams through addressing two main research questions: 1) What changes occur in students’ diversity sensitivity, multicultural effectiveness, and engineering practices as a result of working in diverse teams? 2) How do students’ perceptions of diversity, affect, and engineering practices change because of working on diverse teams? Using a multi-method approach, we deployed survey instruments to determine changes in student’s attitudes about teaming, diversity sensitivity, and openness attitudes. We also observed students working in teams and interviewed these students about their perceptions of diversity and experiences in their teams. Preliminary results of the quantitative phase show that variance in students’ attitudes about diversity significantly increase over the semester, further reflecting the mixed results that have been seen previously in the literature. Additionally, Social Network Analysis was used to characterize the social structure practices of a multi-section, large-enrollment first-year engineering course. This reveals the underlying social structure of the environment, its inclusiveness, and how diverse students work with others on engineering. Initial results indicate that students are included in social networks regardless of gender and race. Preliminary results of the qualitative phase, using Interpretive Phenomenological Analysis, have yielded relationships between student’s definitions, valuation, and enactment of diversity in engineering spaces. Individual student’s incoming attitudes of diversity and previous experiences interact with practical needs in first-year engineering classrooms to create different microclimates within each team. These microclimates depict tensions between what instructors emphasize about diversity, stereotypes of engineering as focused on technical instead of social skills, and pragmatic forces of “getting the job done.” This knowledge can help explain some of the complexity behind the conflicting literature on diversity in teams. Ultimately, this research can help us understand how to build inclusive and diverse environments that guide students to learn how to understand their own complex relationship, understanding, and enactment of diversity in engineering. By understanding how students make sense of diversity in engineering spaces, educators and researchers can figure out how to introduce these concepts in relevant ways so that students can inclusively meet the grand challenges in engineering. This curriculum integration, in turn, can improve team interactions and the climate of engineering for underrepresented groups.more » « less