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1. Characterizing Dominant Field-Scale Cropping Sequences for a Potato and Vegetable Growing Region in Central Wisconsin

   https://doi.org/10.3390/land11020273  

   Heineman, Emily Marrs ; Kucharik, Christopher J. ( February 2022 , Land)

   Crop rotations are known to improve soil health by replenishing lost nutrients, increasing organic matter, improving microbial activity, and reducing disease risk and weed pressure. We characterized the spatial distribution of crops and dominant field-scale cropping sequences from 2008 to 2019 for the Wisconsin Central Sands (WCS) region, a major producer of potato and vegetables in the U.S. The dominant two- and three-year rotations were determined, with an additional focus on assessing regional potato rotation management. Our results suggest corn and soybean are the two most widely planted crops, occurring on 67% and 36% of all agricultural land at least once during the study period. The most frequent two- and three-year crop rotations include corn, soybean, alfalfa, sweet corn, potato, and beans, with continuous corn being the most dominant two- and three-year rotations (13.2% and 8.5% of agricultural land, respectively). While four- and five-year rotations for potato are recommended to combat pest and disease pressure, 23.2% and 65.9% of potato fields returned to that crop in rotation after two and three years, respectively. Furthermore, 5.6% of potato fields were planted continuously with that crop. Given potato’s high nitrogen (N) fertilizer requirements, the prevalence of sandy soils, and ongoing water quality issues, adopting more widespread use of four- or five-year rotations of potato with crops that require zero or less N fertilizer could reduce groundwater nitrate concentrations and improve water quality. 

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2. Excess phosphorus from compost applications in urban gardens creates potential pollution hotspots

   https://doi.org/10.1088/2515-7620/ab3b8c  

   Small, Gaston ; Shrestha, Paliza ; Metson, Geneviève Suzanne ; Polsky, Katherine ; Jimenez, Ivan ; Kay, Adam ( September 2019 , Environmental Research Communications)

   Urban sustainability initiatives often encompass such goals as increasing local food production, closing nutrient loops through recycling organic waste, and reducing water pollution. However, there are potential tradeoffs among these desired outcomes that may constrain progress. For example, expansion of urban agriculture for food production may create hotspots of nutrient pollution if nutrient recycling is inefficient. We used gardener and urban farmer survey data from the Twin Cities Metropolitan Area (Minnesota, USA) to characterize phosphorus (P) and nitrogen (N) inputs and harvest in order to determine nutrient use efficiencies, and measured soil P concentrations at a subset of these sites to test whether excess soil P was common. All survey respondents (n = 142) reported using some form of soil amendment, with plant-based composts being the most common. Median application rates were 300 kg P/ha and 1400 kg N/ha. Median nutrient use efficiencies were low (2.5% for P, 5.0% for N) and there was only a weak positive relationship between P and N inputs and P and N harvested in crop biomass. Garden soils had a median Bray P value of 80 ppm, showing a buildup of plant-available P far exceeding recommended levels. Our results show that urban gardens are characterized by high nutrient inputs and inefficient conversion of these nutrients into crops, leading to buildup and potential loss of P and N from garden soils. Although urban gardens make up only 0.1% of land area in the Twin Cities, compost application to these urban gardens still constitutes one of the largest inputs of P to the watershed. In order to maximize desired outcomes from the expansion of urban agriculture (UA), it will be necessary to target soil amendments based on soil nutrient levels and crop nutrient demand.

    

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3. The impact of country reimbursement programmes on living kidney donations

   https://doi.org/10.1136/bmjgh-2020-002596  

   Siddique, Abu Bakkar ; Apte, Vandana ; Fry-Revere, Sigrid ; Jin, Yanhong ; Koizumi, Naoru ( August 2020 , BMJ Global Health)

   null (Ed.)

   Introduction Living-donor kidney transplantation is the gold standard treatment for patients with end-stage kidney disease. However, potential donors ubiquitously face financial as well as logistical barriers. To remove these disincentives from living kidney donations, the governments of 23 countries have implemented reimbursement programmes that shift the burdens of non-medical costs from donors to the governments or private entities. However, scientific evidence for the effectiveness of these programmes is scarce. The present study investigates whether these reimbursement programmes designed to ease the financial and logistical barriers succeeded in increasing the number of living kidney donations at the country level. The study examined within-country variations in the timing of such reimbursement programmes. Method The study applied the difference-in-difference (two-way panel fixed-effect) technique on the Poisson distribution to estimate the effects of these reimbursement programmes on a 17 year long (2000–2016) dataset covering 109 countries where living donor kidney transplants were performed. Results The results indicated that reimbursement programmes have a statistically significant positive effect. Overall, the model predicted that reimbursement programmes increased country-level donation numbers by a factor of 1.12–1.16. Conclusion Reimbursement programmes may be an effective approach to alleviate the kidney shortage worldwide. Further analysis is warranted on the type of reimbursement programmes and the ethical dimension of each type of such programmes. 

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4. Evidence of fruit syndromes in the recently diverged wild tomato clade opens new possibilities for the study of fleshy fruit evolution

   https://doi.org/10.1002/ppp3.10399  

   Barnett, Jacob R. ; Sharma, Rovin ; Buonauro, Gina ; Gillis, Ian M. ; Rashidzade, Maryam ; Caicedo, Ana L. ( June 2023 , PLANTS, PEOPLE, PLANET)

   Fleshy fruits provide humans with many flavorful and nutritious crops. Understanding the diversity of these plants is fundamental to managing agriculture and food security in a changing world. This study surveyed fruit trait variation across species of tomato wild relatives and explored associations among color, size, shape, sugars, and acids. These wild tomato species native to South America can be interbred with the economically important cultivated tomato. Beyond its application to tomatoes, deepening our knowledge of how fruit traits evolve together is valuable to crop improvement efforts aimed at breeding more nutritious and appealing varieties of fruits.

   Fleshy fruits display a striking diversity of traits, many of which are important for agriculture. The evolutionary drivers of this variation are not well understood, and most studies have relied on variation found in the wild. Few studies have explored this question on a fine‐grained scale with a group of recently diverged species while controlling for environmental effects.

   We developed the tomato clade as a novel system for fruit trait evolution research by presenting the first common garden‐based systematic survey of variation and phylogenetic signal in color, nutrition, and morphology traits across all 13 species of tomato wild relatives (Solanum sect.Lycopersicon). We laid the groundwork for further testing of potential evolutionary drivers by assessing patterns of clustering and correlation among disperser‐relevant fruit traits as well as historical climate variables.

   We found evidence of two distinct clusters of associated fruit traits defined by color, sugar type, and malic acid concentration. We also observed correlations between a fruit's external appearance and internal nutrient content that could function as honest signals to dispersers. Analyses of historical climate and soil variables revealed an association between red/orange/yellow fruits and high annual average temperature.

   Our results establish the tomato clade as a promising system for testing hypotheses on the drivers of divergence behind early‐stage fleshy fruit evolution, particularly selective pressure from frugivores.

    

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5. Understanding the ‘us all’ in Engineering 4 Us All through the Experiences of High School Teachers

   Berhane, B. ; Dalal, M. ; Klein-Gardner, S. ; Carberry, A. ; Reid, K. ; Beauchamp, C. ; Kouo, J. ; Pines, D. ( January 2021 , 3rd annual CoNECD – The Collaborative Network for Engineering and Computing Diversity Conference)

   null (Ed.)

   As our nation’s need for engineering professionals grows, a sharp rise in P-12 engineering education programs and related research has taken place (Brophy, Klein, Portsmore, & Rogers, 2008; Purzer, Strobel, & Cardella, 2014). The associated research has focused primarily on students’ perceptions and motivations, teachers’ beliefs and knowledge, and curricula and program success. The existing research has expanded our understanding of new K-12 engineering curriculum development and teacher professional development efforts, but empirical data remain scarce on how racial and ethnic diversity of student population influences teaching methods, course content, and overall teachers’ experiences. In particular, Hynes et al. (2017) note in their systematic review of P-12 research that little attention has been paid to teachers’ experiences with respect to racially and ethnically diverse engineering classrooms. The growing attention and resources being committed to diversity and inclusion issues (Lichtenstein, Chen, Smith, & Maldonado, 2014; McKenna, Dalal, Anderson, & Ta, 2018; NRC, 2009) underscore the importance of understanding teachers’ experiences with complementary research-based recommendations for how to implement engineering curricula in racially diverse schools to engage all students. Our work examines the experiences of three high school teachers as they teach an introductory engineering course in geographically and distinctly different racially diverse schools across the nation. The study is situated in the context of a new high school level engineering education initiative called Engineering for Us All (E4USA). The National Science Foundation (NSF) funded initiative was launched in 2018 as a partnership among five universities across the nation to ‘demystify’ engineering for high school students and teachers. The program aims to create an all-inclusive high school level engineering course(s), a professional development platform, and a learning community to support student pathways to higher education institutions. An introductory engineering course was developed and professional development was provided to nine high school teachers to instruct and assess engineering learning during the first year of the project. This study investigates participating teachers’ implementation of the course in high schools across the nation to understand the extent to which their experiences vary as a function of student demographic (race, ethnicity, socioeconomic status) and resource level of the school itself. Analysis of these experiences was undertaken using a collective case-study approach (Creswell, 2013) involving in-depth analysis of a limited number of cases “to focus on fewer "subjects," but more "variables" within each subject” (Campbell & Ahrens, 1998, p. 541). This study will document distinct experiences of high school teachers as they teach the E4USA curriculum. Participants were purposively sampled for the cases in order to gather an information-rich data set (Creswell, 2013). The study focuses on three of the nine teachers participating in the first cohort to implement the E4USA curriculum. Teachers were purposefully selected because of the demographic makeup of their students. The participating teachers teach in Arizona, Maryland and Tennessee with predominantly Hispanic, African-American, and Caucasian student bodies, respectively. To better understand similarities and differences among teaching experiences of these teachers, a rich data set is collected consisting of: 1) semi-structured interviews with teachers at multiple stages during the academic year, 2) reflective journal entries shared by the teachers, and 3) multiple observations of classrooms. The interview data will be analyzed with an inductive approach outlined by Miles, Huberman, and Saldaña (2014). All teachers’ interview transcripts will be coded together to identify common themes across participants. Participants’ reflections will be analyzed similarly, seeking to characterize their experiences. Observation notes will be used to triangulate the findings. Descriptions for each case will be written emphasizing the aspects that relate to the identified themes. Finally, we will look for commonalities and differences across cases. The results section will describe the cases at the individual participant level followed by a cross-case analysis. This study takes into consideration how high school teachers’ experiences could be an important tool to gain insight into engineering education problems at the P-12 level. Each case will provide insights into how student body diversity impacts teachers’ pedagogy and experiences. The cases illustrate “multiple truths” (Arghode, 2012) with regard to high school level engineering teaching and embody diversity from the perspective of high school teachers. We will highlight themes across cases in the context of frameworks that represent teacher experience conceptualizing race, ethnicity, and diversity of students. We will also present salient features from each case that connect to potential recommendations for advancing P-12 engineering education efforts. These findings will impact how diversity support is practiced at the high school level and will demonstrate specific novel curricular and pedagogical approaches in engineering education to advance P-12 mentoring efforts. 

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