223 research outputs found

    On the change of growth and wood constructive substances in Salix Koriyanagi which was grown in different soil moisture conditions

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    textabstractThe cellular interactions that drive the formation and maintenance of the insulating myelin sheath around axons are only partially understood. Leucine-rich glioma-inactivated (LGI) proteins play important roles in nervous system development and mutations in their genes have been associated with epilepsy and amyelination. Their function involves interactions with ADAM22 and ADAM23 cell surface receptors, possibly in apposing membranes, thus attenuating cellular interactions. LGI4-ADAM22 interactions are required for axonal sorting and myelination in the developing peripheral nervous system (PNS). Functional analysis revealed that, despite their high homology and affinity for ADAM22, LGI proteins are functionally distinct. To dissect the key residues in LGI proteins required for coordinating axonal sorting and myelination in the developing PNS, we adopted a phylogenetic and computational approach and demonstrate that the mechanism of action of LGI4 depends on a cluster of three amino acids on the outer surface of the LGI4 protein, thus providing a structural basis for the mechanistic differences in LGI protein function in nervous system development and evolution

    Results from the NASA Capability Roadmap Team for In-Situ Resource Utilization (ISRU)

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    On January 14, 2004, the President of the United States unveiled a new vision for robotic and human exploration of space entitled, "A Renewed Spirit of Discovery". As stated by the President in the Vision for Space Exploration (VSE), NASA must "... implement a sustained and affordable human and robotic program to explore the solar system and beyond " and ".. .develop new technologies and harness the moon's abundant resources to allow manned exploration of more challenging environments." A key to fulfilling the goal of sustained and affordable human and robotic exploration will be the ability to use resources that are available at the site of exploration to "live off the land" instead of bringing everything from Earth, known as In-Situ Resource Utilization (ISRU). ISRU can significantly reduce the mass, cost, and risk of exploration through capabilities such as: mission consumable production (propellants, fuel cell reagents, life support consumables, and feedstock for manufacturing & construction); surface construction (radiation shields, landing pads, walls, habitats, etc.); manufacturing and repair with in-situ resources (spare parts, wires, trusses, integrated systems etc.); and space utilities and power from space resources. On January 27th, 2004 the President's Commission on Implementation of U.S. Space Exploration Policy (Aldridge Committee) was created and its final report was released in June 2004. One of the report's recommendations was to establish special project teams to evaluate enabling technologies, of which "Planetary in situ resource utilization" was one of them. Based on the VSE and the commission's final report, NASA established fifteen Capability Roadmap teams, of which ISRU was one of the teams established. From Oct. 2004 to May 2005 the ISRU Capability Roadmap team examined the capabilities, benefits, architecture and mission implementation strategy, critical decisions, current state-of-the-art (SOA), challenges, technology gaps, and risks of ISRU for future human Moon and Mars exploration. This presentation will provide an overview of the ISRU capability, architecture, and implementation strategy examined by the ISRU Capability Roadmap team, along with a top-level review of ISRU benefits, resources and products of interest, and the current SOA in ISRU processes and systems. The presentation will also highlight the challenges of incorporating ISRU into future missions and the gaps in technologies and capabilities that need to be filled to enable ISRU

    Integration of Machine Learning and Mechanistic Models Accurately Predicts Variation in Cell Density of Glioblastoma Using Multiparametric MRI

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    Glioblastoma (GBM) is a heterogeneous and lethal brain cancer. These tumors are followed using magnetic resonance imaging (MRI), which is unable to precisely identify tumor cell invasion, impairing effective surgery and radiation planning. We present a novel hybrid model, based on multiparametric intensities, which combines machine learning (ML) with a mechanistic model of tumor growth to provide spatially resolved tumor cell density predictions. The ML component is an imaging data-driven graph-based semi-supervised learning model and we use the Proliferation-Invasion (PI) mechanistic tumor growth model. We thus refer to the hybrid model as the ML-PI model. The hybrid model was trained using 82 image-localized biopsies from 18 primary GBM patients with pre-operative MRI using a leave-one-patient-out cross validation framework. A Relief algorithm was developed to quantify relative contributions from the data sources. The ML-PI model statistically significantly outperformed (p \u3c 0.001) both individual models, ML and PI, achieving a mean absolute predicted error (MAPE) of 0.106 ± 0.125 versus 0.199 ± 0.186 (ML) and 0.227 ± 0.215 (PI), respectively. Associated Pearson correlation coefficients for ML-PI, ML, and PI were 0.838, 0.518, and 0.437, respectively. The Relief algorithm showed the PI model had the greatest contribution to the result, emphasizing the importance of the hybrid model in achieving the high accuracy

    Asteroid Redirect Mission (ARM) Formulation Assessment and Support Team (FAST) Final Report

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    The Asteroid Redirect Mission (ARM) Formulation Assessment and Support Team (FAST) was a two-month effort, chartered by NASA, to provide timely inputs for mission requirement formulation in support of the Asteroid Redirect Robotic Mission (ARRM) Requirements Closure Technical Interchange Meeting held December 15-16, 2015, to assist in developing an initial list of potential mission investigations, and to provide input on potential hosted payloads and partnerships. The FAST explored several aspects of potential science benefits and knowledge gain from the ARM. Expertise from the science, engineering, and technology communities was represented in exploring lines of inquiry related to key characteristics of the ARRM reference target asteroid (2008 EV5) for engineering design purposes. Specific areas of interest included target origin, spatial distribution and size of boulders, surface geotechnical properties, boulder physical properties, and considerations for boulder handling, crew safety, and containment. In order to increase knowledge gain potential from the mission, opportunities for partnerships and accompanying payloads were also investigated. Potential investigations could be conducted to reduce mission risks and increase knowledge return in the areas of science, planetary defense, asteroid resources and in-situ resource utilization, and capability and technology demonstrations. This report represents the FAST"TM"s final product for the ARM

    High temperature affects olive fruit fly populations in California's Central Valley

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    Olive fruit fly commonly infests olives in California’s Central Valley. Field studies indicate that trap counts for olive fruit fly adults in pesticide-free sites decrease in mid- and late summer and then rebound from September to November. Part of this decline is associated with heat stress that the flies experience in mid-July and August. Studies have shown that adult flies will die within a few days if they cannot access adequate amounts of water and carbohydrates. Flight ability is dramatically reduced when resources are unavailable. Olive fruit fly adults may use black scale honeydew as a carbohydrate source to help them survive hot periods. Heat also affects the fly’s reproduction and immature stages within olive fruit. Geographic information system (GIS) maps may be useful for predicting the risk of olive fruit fly infestation

    Prior COVID-19 infection may increase risk for developing endothelial dysfunction following hematopoietic cell transplantation

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    Endothelial dysfunction underlies many of the major complications following hematopoietic cell transplantation (HCT), including transplant-associated thrombotic microangiopathy (TA-TMA), veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS), and engraftment syndrome (ES). Emerging evidence similarly implicates endothelitis and microangiopathy in severe COVID-19-related multi-system organ dysfunction. Given the overlap in these two illness states, we hypothesize that prior COVID-19 infection may increase risk for HCT-related endotheliopathies. This retrospective, multicenter study included patients aged 0-25 years who underwent autologous or allogeneic HCT for any indication between January 1, 2020 and September 21, 2021, with close attention to those infected with COVID-19 in either the six months prior to transplant or twelve months following transplant. Incidences of TA-TMA, VOD/SOS, and ES were compared among patients with COVID-19 infection pre-HCT and post-HCT, as well as with historical controls who were never infected with SARS-CoV-2. Those who underwent HCT following COVID-19 infection displayed significantly increased rates of TA-TMA compared to those who were never infected. Additionally, our data suggests a similar trend for increased VOD/SOS and ES rates, although this did not reach statistical significance. Therefore, a history of COVID-19 infection prior to undergoing HCT may be a nonmodifiable risk factor for endothelial-related complications following HCT. Further studies are warranted to better clarify this relationship among larger cohorts and in the era of the Omicron SARS-CoV-2 variants
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