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Haplotype-level allelic characterization facilitates research on the functional, evolutionary and breeding-related features of extremely large and complex plant genomes. We report a 21.7-Gb chromosome-level haplotype-resolved assembly in Pinus densiflora. We found genome rearrangements involving translocations and inversions between chromosomes 1 and 3 of Pinus species and a proliferation of specific long terminal repeat (LTR) retrotransposons (LTR-RTs) in P. densiflora. Evolutionary analyses illustrated that tandem and LTR-RT-mediated duplications led to an increment of transcription factor (TF) genes in P. densiflora. The haplotype sequence comparison showed allelic imbalances, including presence–absence variations of genes (PAV genes) and their functional contributions to flowering and abiotic stress-related traits in P. densiflora. Allele-aware resequencing analysis revealed PAV gene diversity across P. densiflora accessions. Our study provides insights into key mechanisms underlying the evolution of genome structure, LTR-RTs and TFs within the Pinus lineage as well as allelic imbalances and diversity across P. densiflora. 

The goal of the National Science Foundation’s International Research Experiences for Students (IRES) program is to provide high quality educational experiences for small groups of U.S. students through active research participation in collaboration with foreign researchers at an international site and provide students with international collaborative research training and a personal network on which to build future collaborations. Interdisciplinary Research in Korea on Applied smart systems (IRiKA) is an NSF IRES Track I program that commenced in 2019. Over the lifetime of this 3-year project (2019 - 2021), a cohort of 5 students selected from three participating U.S. institutions are to be supported each year, making the total number of participants 15. In Summer 2019, the first cohort of five students completed their 8-week immersive research internship at Korea’s top-ranked university. COVID-19 affected most, if not all, in-bound and out-bound international programs. IRiKA was no exception. In late February 2020, the program was canceled altogether because no viable alternative could be offered for Summer 2020, as institutions world-wide were grappling with disruptive challenges the pandemic brought on. In Fall 2020, with contingency plans in place and an additional Korean host site aboard, the project team solicited applications. However, in early 2021, before the final selection of the 2021 cohort was complete, two of the U.S. participating institutions announced that international travel would not be permitted for their faculty and students. The project team went on to select a cohort from one U.S. institution only and continued to monitor the travel health notice level for Korea. While some modifications were made to the in-country program to comply with the COVID-19 regulations in Korea, the 8-week research experience was in-person and remained largely uncompromised for the 2021 cohort. In this Work-in-Progress paper, the three US-based lead investigators compare the two versions of the IRiKA program – before and during the pandemic – and share the lessons learned. The no-cost-extension will allow IRiKA to continue until Summer 2022. Selection of the Summer 2022 cohort will be complete by early March of 2022. 

The goal of the National Science Foundation’s International Research Experiences for Students (IRES) program is to provide high quality educational experiences for small groups of U.S. students through active research participation in collaboration with foreign researchers at an international site and provide students with international collaborative research training and a personal network on which to build future collaborations. Interdisciplinary Research in Korea on Applied smart systems (IRiKA) is an NSF IRES Track I program that commenced in 2019. Over the lifetime of this 3-year project (2019 - 2021), a cohort of 5 students selected from three participating U.S. institutions are to be supported each year, making the total number of participants 15. In Summer 2019, the first cohort of five students completed their 8-week immersive research internship at Korea’s top-ranked university. COVID-19 affected most, if not all, in-bound and out-bound international programs. IRiKA was no exception. In late February 2020, the program was canceled altogether because no viable alternative could be offered for Summer 2020, as institutions world-wide were grappling with disruptive challenges the pandemic brought on. In Fall 2020, with contingency plans in place and an additional Korean host site aboard, the project team solicited applications. However, in early 2021, before the final selection of the 2021 cohort was complete, two of the U.S. participating institutions announced that international travel would not be permitted for their faculty and students. The project team went on to select a cohort from one U.S. institution only and continued to monitor the travel health notice level for Korea. While some modifications were made to the in-country program to comply with the COVID-19 regulations in Korea, the 8-week research experience was in-person and remained largely uncompromised for the 2021 cohort. In this Work-in-Progress paper, the three US-based lead investigators compare the two versions of the IRiKA program – before and during the pandemic – and share the lessons learned. The no-cost-extension will allow IRiKA to continue until Summer 2022. Selection of the Summer 2022 cohort will be complete by early March of 2022. 

Abstract We present an equilibrium model of dynamic trading, learning, and pricing by strategic investors with trading targets and price impact. Since trading targets are private, investors filter the child order flow dynamically over time to estimate the latent underlying parent trading demand imbalance and to forecast its impact on subsequent price-pressure dynamics. We prove existence of an equilibrium and solve for equilibrium trading strategies and prices as the solution to a system of coupled ODEs. Trading strategies are combinations of trading towards investor targets, liquidity provision for other investors’ demands, and speculation based on learning about latent underlying trading-demand imbalances. 

The detection of nucleic acids and their mutation derivatives is vital for biomedical science and applications. Although many nucleic acid biosensors have been developed, they often require pretreatment processes, such as target amplification and tagging probes to nucleic acids. Moreover, current biosensors typically cannot detect sequence-specific mutations in the targeted nucleic acids. To address the above problems, herein, we developed an electrochemical nanobiosensing system using a phenomenon comprising metal ion intercalation into the targeted mismatched double-stranded nucleic acids and a homogeneous Au nanoporous electrode array (Au NPEA) to obtain (i) sensitive detection of viral RNA without conventional tagging and amplifying processes, (ii) determination of viral mutation occurrence in a simple detection manner, and (iii) multiplexed detection of several RNA targets simultaneously. As a proof-of-concept demonstration, a SARS-CoV-2 viral RNA and its mutation derivative were used in this study. Our developed nanobiosensor exhibited highly sensitive detection of SARS-CoV-2 RNA (∼1 fM detection limit) without tagging and amplifying steps. In addition, a single point mutation of SARS-CoV-2 RNA was detected in a one-step analysis. Furthermore, multiplexed detection of several SARS-CoV-2 RNAs was successfully demonstrated using a single chip with four combinatorial NPEAs generated by a 3D printing technique. Collectively, our developed nanobiosensor provides a promising platform technology capable of detecting various nucleic acids and their mutation derivatives in highly sensitive, simple, and time-effective manners for point-of-care biosensing. 

The quartz crystal microbalance (QCM) has been widely used in laboratory settings as an analytical tool for recognizing and discriminating biological and chemical molecules of interest. As a result, recent studies have shown there to be considerable attention in practical applications of the QCM technique beyond the laboratory. However, most commercial QCM instruments are not suitable for off-laboratory usage. For field-deployable applications and in situ detection, the development of a portable QCM measurement system achieving comparable performance to benchtop instruments is highly desired. In this paper, we describe the development of a fully customizable, miniaturized, battery-powered, and cost-efficient QCM system employing a phase-locked loop (PLL) electronic circuit-based QCM measurement system. The performance of this developed system showed a minimum frequency resolution of approximately 0.22 Hz at 0.1 s measurement time. This novel, miniaturized system successfully demonstrated an ability to detect two common volatile organic compounds (VOCs), methanol and dichloromethane (DCM), and the obtained results were comparable to responses from a commercially available benchtop instrument. 

The current three sigma tension in the unitarity test of the Cabbibo-Kobayashi-Maskawa (CKM) matrix is a notable problem with the Standard Model of elementary particle physics. A long-standing goal of the study of free neutron beta decay is to better determine the CKM elementV_udthrough measurements of the neutron lifetime and a decay correlation parameter. The Nab collaboration intends to measurea, the neutrino-electron correlation, with accuracy sufficient for a competitive evaluation ofV_udbased on neutron decay data alone. This paper gives a status report and an outlook.