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1. Advances in Selected Heterocyclization Methods

   https://doi.org/10.1055/s-0042-1751429  

   Rivas, Mónica; Gevorgyan, Vladimir (July 2023, Synlett)

   Abstract This Account summarizes efforts in our group toward synthesis of heterocycles in the past decade. Selected examples of transannulative heterocyclizations, intermediate construction of reactive compounds en route to these important motifs, and newer developments of a radical approach are outlined. 1 Introduction 2 Transannulative Heterocyclization 2.1 Rhodium-Catalyzed Transannulative Heterocyclization 2.2 Copper-Catalyzed Transannulative Heterocyclization 3 Synthesis of Heterocycles from Reactive Precursors 3.1 Synthesis of Heterocycles from Diazo Compounds 3.2 Synthesis of Heterocycles from Alkynones 4 Radical Heterocyclization 4.1 Light-Induced Radical Heterocyclization 4.2 Light-Free Radical Heterocyclization 7 Conclusion 

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2. Multi-instantons in minimal string theory and in matrix integrals

   https://doi.org/10.1007/JHEP10(2022)065  

   Eniceicu, Dan Stefan; Mahajan, Raghu; Murdia, Chitraang; Sen, Ashoke (October 2022, Journal of High Energy Physics)

   A<sc>bstract</sc> We compute the normalization of the general multi-instanton contribution to the partition function of (p′,p) minimal string theory and also to the dual two-matrix integral. We find perfect agreement between the two results. 

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3. Illuminating inequality in access: Variation in enrollment in undergraduate engineering programs across Virginia's high schools

   https://doi.org/10.1002/jee.20352  

   Knight, David B.; Grohs, Jacob R.; Bradburn, Isabel S.; Kinoshita, Timothy J.; Vaziri, Stacey; M. Matusovich, Holly; Carrico, Cheryl (October 2020, Journal of Engineering Education)

   Abstract BackgroundDetermining the root causes of persistent underrepresentation of different subpopulations in engineering remains a continued challenge. Because place‐based variation of resource distribution is not random and because school and community contexts influence high school outcomes, considering variation across those contexts should be paramount in broadening participation research. Purpose/HypothesisThis study takes a macroscopic systems view of engineering enrollments to understand variation across one state's public high school rates of engineering matriculation. Design/MethodThis study uses a dataset from the Virginia Longitudinal Data System that includes all students who completed high school from a Virginia public school from 2007 to 2014 (N= 685,429). We explore geographic variation in four‐year undergraduate engineering enrollment as a function of gender, race/ethnicity, and economically disadvantaged status. Additionally, we investigate the relationship between characteristics of the high school and community contexts and undergraduate engineering enrollment across Virginia's high schools using regression analysis. ResultsOur findings illuminate inequality in enrollment in engineering programs at four‐year institutions across high schools by gender, race, and socioeconomic status (and the intersections among those demographics). Different high schools have different engineering enrollment rates among students who attend four‐year postsecondary institutions. We show strong associations between high schools' engineering enrollment rates and four‐year institution enrollment rates as well as moderate associations for high schools' community socioeconomic status. ConclusionsStrong systemic forces need to be overcome to broaden participation in engineering. We demonstrate the insights that state longitudinal data systems can illuminate in engineering education research. 

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4. Convex polytopes in restricted point sets in R^d

   https://doi.org/10.19086/aic.2025.1  

   Bukh, Boris; Zichao, Dong (January 2025, Advances in Combinatorics)

   For a finite point set P⊂R^d, denote by diam(P) the ratio of the largest to the smallest distances between pairs of points in P. Let c_{d,α}(n) be the largest integer c such that any n-point set P⊂R^d in general position, satisfying diam(P)<αn^{1/d}, contains an c-point convex independent subset. We determine the asymptotics of c_{d,α}(n) as n→∞ by showing the existence of positive constants β=β(d,α) and γ=γ(d) such that βn^{(d−1)/(d+1)}≤c_{d,α}(n)≤γn^{(d−1)/(d+1)} for α≥2. 

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5. Metabolite shift in Medicago truncatula occurs in phosphorus deprivation

   https://doi.org/10.1093/jxb/erab559  

   Dokwal, Dhiraj; Cocuron, Jean-Christophe; Alonso, Ana Paula; Dickstein, Rebecca; Nakamura, ed., Yuki (December 2021, Journal of Experimental Botany)

   Abstract Symbiotic nitrogen (N) fixation entails successful interaction between legume hosts and rhizobia that occur in specialized organs called nodules. N-fixing legumes have a higher demand for phosphorus (P) than legumes grown on mineral N. Medicago truncatula is an important model plant for characterization of effects of P deficiency at the molecular level. Hence, a study was carried out to address the alteration in metabolite levels of M. truncatula grown aeroponically and subjected to 4 weeks of P stress. First, GC-MS-based untargeted metabolomics initially revealed changes in the metabolic profile of nodules, with increased levels of amino acids and sugars and a decline in amounts of organic acids. Subsequently, LC-MS/MS was used to quantify these compounds including phosphorylated metabolites in the whole plant. Our results showed a drastic reduction in levels of organic acids and phosphorylated compounds in –P leaves, with a moderate reduction in –P roots and nodules. Additionally, sugars and amino acids were elevated in the whole plant under P deprivation. These findings provide evidence that N fixation in M. truncatula is mediated through a N feedback mechanism that in parallel is related to carbon and P metabolism. 

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