Results for “root development” — Page 51

DOE OSTI2021

Understanding Multilevel Selection May Facilitate Management of Arbuscular Mycorrhizae in Sustainable Agroecosystems

Studies in natural ecosystems show that adaptation of arbuscular mycorrhizal (AM) fungi and other microbial plant symbionts to local environmental conditions can help ameliorate stress and optimize plant fitness. This local adaptation arises from the process of multilevel selection, which is the simultaneous selection of a hierarchy of groups. Studies of multilevel selection in natural ecosystems may inform the creation of sustainable agroecosystems through developing strategies to effectively manage crop microbiomes including AM symbioses. Field experiments show that the species composition of AM fungal communities varies across environmental gradients, and that the biomass of AM fungi and their benefits for plants generally diminish when fertilization and irrigation eliminate nutrient and water limitations. Furthermore, pathogen protection by mycorrhizas is only important in environments prone to plant damage due to pathogens. Consequently, certain agricultural practices may inadvertently select for less beneficial root symbioses because the conventional agricultural practices of fertilization, irrigation, and use of pesticides can make these symbioses superfluous for optimizing crop performance. The purpose of this paper is to examine how multilevel selection influences the flow of matter, energy, and genetic information through mycorrhizal microbiomes in natural and agricultural ecosystems, and propose testable hypotheses about how mycorrhizae may be actively managed to increase agricultural sustainability.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2016

GLASS daytime all-wave net radiation product: Algorithm development and preliminary validation

Mapping surface all-wave net radiation (R n ) is critically needed for various applications. Several existing R n products from numerical models and satellite observations have coarse spatial resolutions and their accuracies may not meet the requirements of land applications. In this study, we develop the Global LAnd Surface Satellite (GLASS) daytime R n product at a 5 km spatial resolution. Its algorithm for converting shortwave radiation to all-wave net radiation using the Multivariate Adaptive Regression Splines (MARS) model is determined after comparison with three other algorithms. The validation of the GLASS R n product based on high-quality in situ measurements in the United States shows a coefficient of determination value of 0.879, an average root mean square error value of 31.61 Wm -2 , and an average bias of 17.59 Wm -2 . Furthermore, we also compare our product/algorithm with another satellite product (CERES-SYN) and two reanalysis products (MERRA and JRA55), and find that the accuracy of the much higher spatial resolution GLASS R n product is satisfactory. The GLASS R n product from 2000 to the present is operational and freely available to the public.

58 GEOSCIENCES↗

DOE OSTI2016

WE-H-201-00: Opportunities for Physicists to Support Low and Mid-Income Countries

The desperate need for radiotherapy in low and mid-income countries (LMICs) has been well documented. Roughly 60 % of the worldwide incidence of cancer occurs in these resource-limited settings and the international community alongside governmental and non-profit agencies have begun publishing reports and seeking help from qualified volunteers. However, the focus of several reports has been on how dire the situation is and the magnitude of the problem, leaving most to feel overwhelmed and unsure as to how to help and why to get involved. This session will help to explain the specific ways that Medical Physicists can uniquely assist in this grand effort to help bring radiotherapy to grossly-underserved areas. Not only can these experts fulfill an important purpose, they also can benefit professionally, academically, emotionally and socially from the endeavor. By assisting others worldwide with their skillset, Medical Physicists can end up helping themselves. Learning Objectives: Understand the need for radiotherapy in LMICs. Understand which agencies are seeking Medical Physicists for help in LMICs. Understand the potential research funding mechanisms are available to establish academic collaborations with LMIC researchers/physicians. Understand the potential social and emotional benefits for both the physicist and the LMIC partners when collaborations are made. Understand the potential for collaboration with other high-income scientists that can develop as the physicist partners with other large institutions to assist LMICs. Wil Ngwa - A recent United Nations Study reports that in developing countries more people have access to cell phones than toilets. In Africa, only 63% of the population has access to piped water, yet, 93% of Africans have cell phone service. Today, these cell phones, Skype, WhatsApp and other information and communication technologies (ICTs) connect us in unprecedented ways and are increasingly recognized as powerful, indispensable to global health. Thanks to ICTs, there are growing opportunities for Medical Physicists to reach out beyond the bunker and impact the world far beyond, without even having to travel. These growing opportunities in global health for Medical Physicists, powered by ICTs, will be highlighted in this presentation, illustrated by high impact examples/models across the globe that are improving patient safety and healthcare outcomes, saving lives. Learning Objectives: Published definitions of global health and the emerging field of global radiation oncology Learn about the transformative potential of ICTs in global radiation oncology care, research and education with focus on Medical Physics Learn about high impact examples of ICT-powered global radiation oncology and the increasing opportunities for participation by Medical Physicists. Yakov Pipman - The number and scope of volunteer Medical Physics activities in support of low-to-middle income countries has been increasing gradually. This happens through a variety of formal channels and to some extent through less formal but personal initiatives. A good deal of effort is dedicated by many, but many more could be recruited through a structured framework to volunteer. We will look into typical volunteer activities and how they fit with organizations already involved in advancing Medical Physics in LMIC. We will identify the range of these organizational activities and their scope to reveal areas of further need. We will point to a few key features of MPWB ( http://www.mpwb.org ) as a volunteering and collaborating structure and how members can get involved and contribute to these efforts at the grass roots level. The goal is that scarce resources can thus be channeled to complement rather than compete with those already in place. Learning Objectives: Understand the strengths and limitations of various organizations that support Medical Physics efforts in LMIC. Learn about ways to volunteer and contribute to Global Health through a grass roots organization focused on Medical Physics in LMIC. Perry Sprawls - With the growing capability and complexity of medical imaging methods in all countries of the world, the expanding role of medical physicists includes optimizing imaging procedures with respect to image quality, radiation dose, and other conflicting factors. With access to appropriate educational resources local medical physicists in all countries can provide direct clinical support and educational for other medical professionals. This is being supported through the process of Collaborative Teaching that combines the capabilities and experience of medical physicists in countries spanning the spectrum of economic, technological, and clinical development. The supporting resources are on the web at: http://www.sprawls.org/resources . Learning Objectives: Identify the medical physics educational needs to support effective and optimized medical imaging procedures. Use collaborative teaching resources to enhance the role of medical physicists in all countries of the world.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

WE-H-201-01: The Opportunities and Benefits of Helping LMICs: How Helping Them Can Help You

The desperate need for radiotherapy in low and mid-income countries (LMICs) has been well documented. Roughly 60 % of the worldwide incidence of cancer occurs in these resource-limited settings and the international community alongside governmental and non-profit agencies have begun publishing reports and seeking help from qualified volunteers. However, the focus of several reports has been on how dire the situation is and the magnitude of the problem, leaving most to feel overwhelmed and unsure as to how to help and why to get involved. This session will help to explain the specific ways that Medical Physicists can uniquely assist in this grand effort to help bring radiotherapy to grossly-underserved areas. Not only can these experts fulfill an important purpose, they also can benefit professionally, academically, emotionally and socially from the endeavor. By assisting others worldwide with their skillset, Medical Physicists can end up helping themselves. Learning Objectives: Understand the need for radiotherapy in LMICs. Understand which agencies are seeking Medical Physicists for help in LMICs. Understand the potential research funding mechanisms are available to establish academic collaborations with LMIC researchers/physicians. Understand the potential social and emotional benefits for both the physicist and the LMIC partners when collaborations are made. Understand the potential for collaboration with other high-income scientists that can develop as the physicist partners with other large institutions to assist LMICs. Wil Ngwa - A recent United Nations Study reports that in developing countries more people have access to cell phones than toilets. In Africa, only 63% of the population has access to piped water, yet, 93% of Africans have cell phone service. Today, these cell phones, Skype, WhatsApp and other information and communication technologies (ICTs) connect us in unprecedented ways and are increasingly recognized as powerful, indispensable to global health. Thanks to ICTs, there are growing opportunities for Medical Physicists to reach out beyond the bunker and impact the world far beyond, without even having to travel. These growing opportunities in global health for Medical Physicists, powered by ICTs, will be highlighted in this presentation, illustrated by high impact examples/models across the globe that are improving patient safety and healthcare outcomes, saving lives. Learning Objectives: Published definitions of global health and the emerging field of global radiation oncology Learn about the transformative potential of ICTs in global radiation oncology care, research and education with focus on Medical Physics Learn about high impact examples of ICT-powered global radiation oncology and the increasing opportunities for participation by Medical Physicists. Yakov Pipman - The number and scope of volunteer Medical Physics activities in support of low-to-middle income countries has been increasing gradually. This happens through a variety of formal channels and to some extent through less formal but personal initiatives. A good deal of effort is dedicated by many, but many more could be recruited through a structured framework to volunteer. We will look into typical volunteer activities and how they fit with organizations already involved in advancing Medical Physics in LMIC. We will identify the range of these organizational activities and their scope to reveal areas of further need. We will point to a few key features of MPWB ( http://www.mpwb.org ) as a volunteering and collaborating structure and how members can get involved and contribute to these efforts at the grass roots level. The goal is that scarce resources can thus be channeled to complement rather than compete with those already in place. Learning Objectives: Understand the strengths and limitations of various organizations that support Medical Physics efforts in LMIC. Learn about ways to volunteer and contribute to Global Health through a grass roots organization focused on Medical Physics in LMIC. Perry Sprawls - With the growing capability and complexity of medical imaging methods in all countries of the world, the expanding role of medical physicists includes optimizing imaging procedures with respect to image quality, radiation dose, and other conflicting factors. With access to appropriate educational resources local medical physicists in all countries can provide direct clinical support and educational for other medical professionals. This is being supported through the process of Collaborative Teaching that combines the capabilities and experience of medical physicists in countries spanning the spectrum of economic, technological, and clinical development. The supporting resources are on the web at: http://www.sprawls.org/resources . Learning Objectives: Identify the medical physics educational needs to support effective and optimized medical imaging procedures. Use collaborative teaching resources to enhance the role of medical physicists in all countries of the world.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

WE-H-201-02: Emerging Models and Opportunities in Global Health for Medical Physicists Powered by Information and Communication Technologies

The desperate need for radiotherapy in low and mid-income countries (LMICs) has been well documented. Roughly 60 % of the worldwide incidence of cancer occurs in these resource-limited settings and the international community alongside governmental and non-profit agencies have begun publishing reports and seeking help from qualified volunteers. However, the focus of several reports has been on how dire the situation is and the magnitude of the problem, leaving most to feel overwhelmed and unsure as to how to help and why to get involved. This session will help to explain the specific ways that Medical Physicists can uniquely assist in this grand effort to help bring radiotherapy to grossly-underserved areas. Not only can these experts fulfill an important purpose, they also can benefit professionally, academically, emotionally and socially from the endeavor. By assisting others worldwide with their skillset, Medical Physicists can end up helping themselves. Learning Objectives: Understand the need for radiotherapy in LMICs. Understand which agencies are seeking Medical Physicists for help in LMICs. Understand the potential research funding mechanisms are available to establish academic collaborations with LMIC researchers/physicians. Understand the potential social and emotional benefits for both the physicist and the LMIC partners when collaborations are made. Understand the potential for collaboration with other high-income scientists that can develop as the physicist partners with other large institutions to assist LMICs. Wil Ngwa - A recent United Nations Study reports that in developing countries more people have access to cell phones than toilets. In Africa, only 63% of the population has access to piped water, yet, 93% of Africans have cell phone service. Today, these cell phones, Skype, WhatsApp and other information and communication technologies (ICTs) connect us in unprecedented ways and are increasingly recognized as powerful, indispensable to global health. Thanks to ICTs, there are growing opportunities for Medical Physicists to reach out beyond the bunker and impact the world far beyond, without even having to travel. These growing opportunities in global health for Medical Physicists, powered by ICTs, will be highlighted in this presentation, illustrated by high impact examples/models across the globe that are improving patient safety and healthcare outcomes, saving lives. Learning Objectives: Published definitions of global health and the emerging field of global radiation oncology Learn about the transformative potential of ICTs in global radiation oncology care, research and education with focus on Medical Physics Learn about high impact examples of ICT-powered global radiation oncology and the increasing opportunities for participation by Medical Physicists. Yakov Pipman - The number and scope of volunteer Medical Physics activities in support of low-to-middle income countries has been increasing gradually. This happens through a variety of formal channels and to some extent through less formal but personal initiatives. A good deal of effort is dedicated by many, but many more could be recruited through a structured framework to volunteer. We will look into typical volunteer activities and how they fit with organizations already involved in advancing Medical Physics in LMIC. We will identify the range of these organizational activities and their scope to reveal areas of further need. We will point to a few key features of MPWB ( http://www.mpwb.org ) as a volunteering and collaborating structure and how members can get involved and contribute to these efforts at the grass roots level. The goal is that scarce resources can thus be channeled to complement rather than compete with those already in place. Learning Objectives: Understand the strengths and limitations of various organizations that support Medical Physics efforts in LMIC. Learn about ways to volunteer and contribute to Global Health through a grass roots organization focused on Medical Physics in LMIC. Perry Sprawls - With the growing capability and complexity of medical imaging methods in all countries of the world, the expanding role of medical physicists includes optimizing imaging procedures with respect to image quality, radiation dose, and other conflicting factors. With access to appropriate educational resources local medical physicists in all countries can provide direct clinical support and educational for other medical professionals. This is being supported through the process of Collaborative Teaching that combines the capabilities and experience of medical physicists in countries spanning the spectrum of economic, technological, and clinical development. The supporting resources are on the web at: http://www.sprawls.org/resources . Learning Objectives: Identify the medical physics educational needs to support effective and optimized medical imaging procedures. Use collaborative teaching resources to enhance the role of medical physicists in all countries of the world.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

WE-H-201-03: Enthusiasm and Generosity of Spirit Necessitate a Volunteering Structure to Make Them More Meaningful

The desperate need for radiotherapy in low and mid-income countries (LMICs) has been well documented. Roughly 60 % of the worldwide incidence of cancer occurs in these resource-limited settings and the international community alongside governmental and non-profit agencies have begun publishing reports and seeking help from qualified volunteers. However, the focus of several reports has been on how dire the situation is and the magnitude of the problem, leaving most to feel overwhelmed and unsure as to how to help and why to get involved. This session will help to explain the specific ways that Medical Physicists can uniquely assist in this grand effort to help bring radiotherapy to grossly-underserved areas. Not only can these experts fulfill an important purpose, they also can benefit professionally, academically, emotionally and socially from the endeavor. By assisting others worldwide with their skillset, Medical Physicists can end up helping themselves. Learning Objectives: Understand the need for radiotherapy in LMICs. Understand which agencies are seeking Medical Physicists for help in LMICs. Understand the potential research funding mechanisms are available to establish academic collaborations with LMIC researchers/physicians. Understand the potential social and emotional benefits for both the physicist and the LMIC partners when collaborations are made. Understand the potential for collaboration with other high-income scientists that can develop as the physicist partners with other large institutions to assist LMICs. Wil Ngwa - A recent United Nations Study reports that in developing countries more people have access to cell phones than toilets. In Africa, only 63% of the population has access to piped water, yet, 93% of Africans have cell phone service. Today, these cell phones, Skype, WhatsApp and other information and communication technologies (ICTs) connect us in unprecedented ways and are increasingly recognized as powerful, indispensable to global health. Thanks to ICTs, there are growing opportunities for Medical Physicists to reach out beyond the bunker and impact the world far beyond, without even having to travel. These growing opportunities in global health for Medical Physicists, powered by ICTs, will be highlighted in this presentation, illustrated by high impact examples/models across the globe that are improving patient safety and healthcare outcomes, saving lives. Learning Objectives: Published definitions of global health and the emerging field of global radiation oncology Learn about the transformative potential of ICTs in global radiation oncology care, research and education with focus on Medical Physics Learn about high impact examples of ICT-powered global radiation oncology and the increasing opportunities for participation by Medical Physicists. Yakov Pipman - The number and scope of volunteer Medical Physics activities in support of low-to-middle income countries has been increasing gradually. This happens through a variety of formal channels and to some extent through less formal but personal initiatives. A good deal of effort is dedicated by many, but many more could be recruited through a structured framework to volunteer. We will look into typical volunteer activities and how they fit with organizations already involved in advancing Medical Physics in LMIC. We will identify the range of these organizational activities and their scope to reveal areas of further need. We will point to a few key features of MPWB ( http://www.mpwb.org ) as a volunteering and collaborating structure and how members can get involved and contribute to these efforts at the grass roots level. The goal is that scarce resources can thus be channeled to complement rather than compete with those already in place. Learning Objectives: Understand the strengths and limitations of various organizations that support Medical Physics efforts in LMIC. Learn about ways to volunteer and contribute to Global Health through a grass roots organization focused on Medical Physics in LMIC. Perry Sprawls - With the growing capability and complexity of medical imaging methods in all countries of the world, the expanding role of medical physicists includes optimizing imaging procedures with respect to image quality, radiation dose, and other conflicting factors. With access to appropriate educational resources local medical physicists in all countries can provide direct clinical support and educational for other medical professionals. This is being supported through the process of Collaborative Teaching that combines the capabilities and experience of medical physicists in countries spanning the spectrum of economic, technological, and clinical development. The supporting resources are on the web at: http://www.sprawls.org/resources . Learning Objectives: Identify the medical physics educational needs to support effective and optimized medical imaging procedures. Use collaborative teaching resources to enhance the role of medical physicists in all countries of the world.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

WE-H-201-04: Models for Developing Medical Physics Educators and Education Programs in the Developing Countries and the Potential Role of US Universities and Individual Medical Physicists

The desperate need for radiotherapy in low and mid-income countries (LMICs) has been well documented. Roughly 60 % of the worldwide incidence of cancer occurs in these resource-limited settings and the international community alongside governmental and non-profit agencies have begun publishing reports and seeking help from qualified volunteers. However, the focus of several reports has been on how dire the situation is and the magnitude of the problem, leaving most to feel overwhelmed and unsure as to how to help and why to get involved. This session will help to explain the specific ways that Medical Physicists can uniquely assist in this grand effort to help bring radiotherapy to grossly-underserved areas. Not only can these experts fulfill an important purpose, they also can benefit professionally, academically, emotionally and socially from the endeavor. By assisting others worldwide with their skillset, Medical Physicists can end up helping themselves. Learning Objectives: Understand the need for radiotherapy in LMICs. Understand which agencies are seeking Medical Physicists for help in LMICs. Understand the potential research funding mechanisms are available to establish academic collaborations with LMIC researchers/physicians. Understand the potential social and emotional benefits for both the physicist and the LMIC partners when collaborations are made. Understand the potential for collaboration with other high-income scientists that can develop as the physicist partners with other large institutions to assist LMICs. Wil Ngwa - A recent United Nations Study reports that in developing countries more people have access to cell phones than toilets. In Africa, only 63% of the population has access to piped water, yet, 93% of Africans have cell phone service. Today, these cell phones, Skype, WhatsApp and other information and communication technologies (ICTs) connect us in unprecedented ways and are increasingly recognized as powerful, indispensable to global health. Thanks to ICTs, there are growing opportunities for Medical Physicists to reach out beyond the bunker and impact the world far beyond, without even having to travel. These growing opportunities in global health for Medical Physicists, powered by ICTs, will be highlighted in this presentation, illustrated by high impact examples/models across the globe that are improving patient safety and healthcare outcomes, saving lives. Learning Objectives: Published definitions of global health and the emerging field of global radiation oncology Learn about the transformative potential of ICTs in global radiation oncology care, research and education with focus on Medical Physics Learn about high impact examples of ICT-powered global radiation oncology and the increasing opportunities for participation by Medical Physicists. Yakov Pipman - The number and scope of volunteer Medical Physics activities in support of low-to-middle income countries has been increasing gradually. This happens through a variety of formal channels and to some extent through less formal but personal initiatives. A good deal of effort is dedicated by many, but many more could be recruited through a structured framework to volunteer. We will look into typical volunteer activities and how they fit with organizations already involved in advancing Medical Physics in LMIC. We will identify the range of these organizational activities and their scope to reveal areas of further need. We will point to a few key features of MPWB ( http://www.mpwb.org ) as a volunteering and collaborating structure and how members can get involved and contribute to these efforts at the grass roots level. The goal is that scarce resources can thus be channeled to complement rather than compete with those already in place. Learning Objectives: Understand the strengths and limitations of various organizations that support Medical Physics efforts in LMIC. Learn about ways to volunteer and contribute to Global Health through a grass roots organization focused on Medical Physics in LMIC. Perry Sprawls - With the growing capability and complexity of medical imaging methods in all countries of the world, the expanding role of medical physicists includes optimizing imaging procedures with respect to image quality, radiation dose, and other conflicting factors. With access to appropriate educational resources local medical physicists in all countries can provide direct clinical support and educational for other medical professionals. This is being supported through the process of Collaborative Teaching that combines the capabilities and experience of medical physicists in countries spanning the spectrum of economic, technological, and clinical development. The supporting resources are on the web at: http://www.sprawls.org/resources . Learning Objectives: Identify the medical physics educational needs to support effective and optimized medical imaging procedures. Use collaborative teaching resources to enhance the role of medical physicists in all countries of the world.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2021

Cell-Type-Specific Proteomics Analysis of a Small Number of Plant Cells by Integrating Laser Capture Microdissection with a Nanodroplet Sample Processing Platform

Plant organs and tissues contain multiple cell types, which are well organized in 3-dimensional structure to efficiently perform physiological functions such as homeostasis, response to environmental perturbation, pathogen infection. It is critically important to perform molecular measurements at the cell-type-specific level to discover mechanisms and unique features of cell populations that govern differentiation and respond to external perturbations. Although mass spectrometry-based proteomics has been demonstrated as an enabling discovery tool to study plant physiology, conventional approaches require millions of cells to generate robust biological conclusions. Such requirements mask the cell-to-cell heterogeneities and limit the comprehensive profiling of plant proteins at spatially resolved and cell-type-specific resolutions. This protocol describes a recently-developed proteomics workflow for studying a small number of plant cells by integrating laser capture microdissection, microfluidic nanodroplet-based sample preparation, with ultrasensitive liquid chromatography-mass spectrometry. Using poplar as a model tree species, we provide detailed protocols, including plant tissue harvest, tissue preparation, cryosectioning, laser microdissection, protein digestion, mass spectrometry measurement, and data analysis. We show the workflow enables the precise identification and quantification of thousands of proteins from hundreds of isolated plant root and leaf cells.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2023

Drought conditioning of rhizosphere microbiome influences maize water use traits

Background and Aims: Beneficial plant–microbe interactions can improve plant performance under drought; however, we know less about how drought-induced shifts in microbial communities affect plant traits. Methods: We cultivated Zea mays in fritted clay with soil microbiomes originating from contrasting environments (agriculture or forest) under two irrigation treatments (well-watered or water limited). Using this design, we investigated whether water conditioning was carried forward through the microbiome to affect a subsequent plant cohort that was subjected to either a well-watered or water limited treatment. Results: Regardless of the microbiome-origin, plants inoculated with a microbiome from a water limited legacy had traits that allowed them to avoid stress but conserve water. They produced longer roots to explore soil, generated greater soil dissolved organic carbon, potentially stimulating the microbiome, and slower soil water content loss during drought. A well-watered legacy resulted in plants that delayed permanent stomatal closure and higher photosynthetic nitrogen use efficiency. In plants with a forest-originated microbiome, a well-watered legacy and water treatment also resulted in higher rates of photosynthesis and stomatal conductance. Conclusion: These results demonstrate that soil microbiomes can be developed to influence plant drought performance, impacting crop resilience, using short-term microbial conditioning.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

Ion-Exchange Interdiffusion Model with Potential Application to Long-Term Nuclear Waste Glass Performance

Ion exchange is an integral mechanism influencing the corrosion of glasses. Due to the formation of alteration layers in aqueous conditions, it is difficult to conclusively deconvolute the process of ion exchange from other processes, principally dissolution of the glass matrix. Therefore, we have developed a method to isolate alkali diffusion that involves contacting glass coupons with a solution of 6 LiCl dissolved in functionally inert dimethyl sulfoxide. Here, we employ the method at temperatures ranging from 25 to 150 °C with various glass formulations. Glass compositions include simulant nuclear waste glasses, such as SON68 and the international simple glass (ISG), glasses in which the nature of the alkali element was varied, and glasses that contained more than one alkali element. An interdiffusion model based on Fick’s second law was developed and applied to all experiments to extract diffusion coefficients. The model expands established models of interdiffusion to the case where multiple types of alkali sites are present in the glass. Activation energies for alkali ion exchange were calculated and the results are in agreement with those obtained in glass strengthening experiments but are nearly five times higher than values reported for diffusion-controlled processes in nuclear waste glass corrosion experiments. A discussion of the root causes for this apparent discrepancy is provided. The interdiffusion model derived from laboratory experiments is expected to be useful for modeling glass corrosion in a geological repository when the silicon concentration is high.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2019

Plant selection initiates alternative successional trajectories in the soil microbial community after disturbance

Because interactions between plants and microbial organisms can influence species diversity and rates of nutrient cycling, how plants shape microbial communities is fundamental to understanding the structure of ecosystems. Despite this, the spatial and temporal scales over which plants influence microbial communities is poorly understood, particularly whether past abiotic or biotic legacies strongly constrain microbial community development. We examined biogeochemical cycling and microbial community structure in a coastal landscape where historical patterns of vegetation transition after a large fire in 1995 are well known, allowing us to account for past abiotic and biotic conditions. We found that alternative states in microbial community structure and ecosystem processes emerged under different plant species, regardless of past conditions. Greenhouse studies further demonstrated that these differences arise from direct plant selection of microbes, with selection stronger in roots compared with soils, especially for bacteria. Correlation of microbial community structure with seedling growth rates was also stronger for fungi compared to bacteria. Despite these effects, minimal overlap between seedling and field microbial communities indicates that the effects of initial plant selection are not stable, rather plant selection initiated alternative successional trajectories after the fire. Using data from a guild where we have abundant natural history information - ectomycorrhizal fungi - we show that greenhouse communities are dominated by ruderal taxa that are also common in the field after the fire, and that these ruderal fungi strongly alter spatial patterns in plant-soil feedback, enabling invasion and transformation of soils previously occupied by heterospecific plants, thus potentially acting as keystone mutualists.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2019

Self-Evolving Machine: A Continuously Improving Model for Molecular Thermochemistry

Because collecting precise and accurate chemistry data is often challenging, chemistry data sets usually only span a small region of chemical space, which limits the performance and the scope of applicability of data-driven models. To address this issue, we integrated an active learning machine with automatic ab initio calculations to form a self-evolving model that can continuously adapt to new species appointed by the users. In the present work, we demonstrate the self-evolving concept by modeling the formation enthalpies of stable closed-shell polycyclic species calculated at the B3LYP/6-31G(2df,p) level of theory. By combining a molecular graph convolutional neural network with a dropout training strategy, the model we developed can predict density functional theory (DFT) enthalpies for a broad range of polycyclic species and assess the quality of each predicted value. For the species which the current model is uncertain about, the automatic ab initio calculations provide additional training data to improve the performance of the model. For a test set composed of 2858 cyclic and polycyclic hydrocarbons and oxygenates, the enthalpies predicted by the model agree with the reference DFT values with a root-mean-square error of 2.62 kcal/mol. Finally, we found that a model originally trained on hydrocarbons and oxygenates can broaden its prediction coverage to nitrogen-containing species via an active learning process, suggesting that the continuous learning strategy is not only able to improve the model accuracy but is also capable of expanding the predictive capacity of a model to unseen species domains.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2016

Multiview marker-free registration of forest terrestrial laser scanner data with embedded confidence metrics

Terrestrial laser scanning has demonstrated increasing potential for rapid comprehensive measurement of forest structure, especially when multiple scans are spatially registered in order to reduce the limitations of occlusion. Although marker-based registration techniques (based on retro-reflective spherical targets) are commonly used in practice, a blind marker-free approach is preferable, insofar as it supports rapid operational data acquisition. To support these efforts, we extend the pairwise registration approach of our earlier work, and develop a graph-theoretical framework to perform blind marker-free global registration of multiple point cloud data sets. Pairwise pose estimates are weighted based on their estimated error, in order to overcome pose conflict while exploiting redundant information and improving precision. The proposed approach was tested for eight diverse New England forest sites, with 25 scans collected at each site. Quantitative assessment was provided via a novel embedded confidence metric, with a mean estimated root-mean-square error of 7.2 cm and 89% of scans connected to the reference node. Lastly, this paper assesses the validity of the embedded multiview registration confidence metric and evaluates the performance of the proposed registration algorithm.

47 OTHER INSTRUMENTATION↗

DOE OSTI2021

Do woody vines use gelatinous fibers to climb?

Many plant movements are facilitated by contractile cells called gelatinous fibers (G-fibers), but how G-fibers function in the climbing movements of woody vines remains underexplored. In this report, we compare the presence and distribution of G-fibers in the stems of stem-twiners, which wrap around supports, with non-stem-twiners, which attach to supports via tendrils or adventitious roots. An examination of 164 species spanning the vascular plant phylogeny reveals that G-fibers are common in stem-twiners but scarce in non-stem-twiners, suggesting that G-fibers are preferentially formed in the organ responsible for movement. When present, G-fibers are in the xylem, phloem, pericycle, and/or cortex. We discuss the hypothesis that G-fibers are foundational to plant movement and highlight research opportunities concerning G-fiber development and function.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2026

Multi‐season analysis reveals hundreds of drought‐responsive genes in sorghum

Persistent drought affects global crop production and is becoming more severe in many parts of the world in recent decades. Deciphering how plants respond to drought will facilitate the development of flexible mitigation strategies. Sorghum bicolor L. Moench (sorghum), a major cereal crop and an emerging bioenergy crop, exhibits remarkable resilience to drought. To better understand the molecular traits that underlie sorghum's remarkable drought tolerance, we undertook a large-scale sorghum gene expression profiling effort, totaling nearly 1500 transcriptome profiles, across a 3-year field study with replicated plots in California's Central Valley. This study included time-resolved gene expression data from roots and leaves of two sorghum genotypes, BTx642 and RTx430, with different pre-flowering and post-flowering drought-tolerance adaptations under control and drought conditions. Quantification of genotype-specific drought tolerance effects was enabled by de novo sequencing, assembly, and annotation of both BTx642 and RTx430 genomes. These reference-quality genomes were used to construct a pangene set for characterizing conserved and genotype-specific expression. By integrating time-resolved transcriptomic responses to drought in the field across three consecutive years, we identified a set of 726 drought-responsive genes that responded similarly in all 3 years of our field study. Functional enrichment analysis identified abiotic stress, secondary cell wall-related processes and metabolism as particularly affected under both types of drought stress. We also found that some glyoxylate cycle pathway genes, including malate synthase and isocitrate lyase, are differentially regulated particularly during post-flowering drought stress, implicating this pathway as potentially important for drought responsiveness. This expansive dataset represents a unique resource for sorghum and drought research communities and provides a methodological framework for the integration of multi-faceted time-resolved transcriptomic datasets.

Cole, Benjamin [USDOE Joint Genome Institute (JGI)↗

DOE OSTI2016

SU-F-T-540: Comprehensive Fluence Delivery Optimization with Multileaf Collimation

Purpose: Multileaf collimator (MLC) leaf sequencing is performed via commercial black-box implementations, on which a user has limited to no access. We have developed an explicit, generic MLC sequencing model to serve as a tool for future investigations of fluence map optimization, fluence delivery optimization, and rotational collimator delivery methods. Methods: We have developed a novel, comprehensive model to effectively account for a variety of transmission and penumbra effects previously treated on an ad hoc basis in the literature. As the model is capable of quantifying a variety of effects, we utilize the asymmetric leakage intensity across each leaf to deliver fluence maps with pixel size smaller than the narrowest leaf width. Developed using linear programming and mixed integer programming formulations, the model is implemented using state of the art open-source solvers. To demonstrate the versatility of the algorithm, a graphical user interface (GUI) was developed in MATLAB capable of accepting custom leaf specifications and transmission parameters. As a preliminary proof-ofconcept, we have sequenced the leaves of a Varian 120 Leaf Millennium MLC for five prostate cancer patient fields and one head and neck field. Predetermined fluence maps have been processed by data smoothing methods to obtain pixel sizes of 2.5 cm{sup 2}. The quality of output was analyzed using computer simulations. Results: For the prostate fields, an average root mean squared error (RMSE) of 0.82 and gamma (0.5mm/0.5%) of 91.4% were observed compared to RMSE and gamma (0.5mm/0.5%) values of 7.04 and 34.0% when the leakage considerations were omitted. Similar results were observed for the head and neck case. Conclusion: A model to sequence MLC leaves to optimality has been proposed. Future work will involve extensive testing and evaluation of the method on clinical MLCs and comparison with black-box leaf sequencing algorithms currently used by commercial treatment planning systems.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2022

Monitoring of Temperature Measurements for Different Flow Regimes in Water and Galinstan with Long Short-Term Memory Networks and Transfer Learning of Sensors

Temperature sensing is one of the most common measurements of a nuclear reactor monitoring system. The coolant fluid flow in a reactor core depends on the reactor power state. We investigated the monitoring and estimation of the thermocouple time series using machine learning for a range of flow regimes. Measurement data were obtained, in two separate experiments, in a flow loop filled with water and with liquid metal Galinstan. We developed long short-term memory (LSTM) recurrent neural networks (RNNs) for sensor predictions by training on the sensor’s own prior history, and transfer learning LSTM (TL-LSTM) by training on a correlated sensor’s prior history. Sensor cross-correlations were identified by calculating the Pearson correlation coefficient of the time series. The accuracy of LSTM and TL-LSTM predictions of temperature was studied as a function of Reynolds number (Re). The root-mean-square error (RMSE) for the test segment of time series of each sensor was shown to linearly increase with Re for both water and Galinstan fluids. Using linear correlations, we estimated the range of values of Re for which RMSE is smaller than the thermocouple measurement uncertainty. For both water and Galinstan fluids, we showed that both LSTM and TL-LSTM provide reliable estimations of temperature for typical flow regimes in a nuclear reactor. The LSTM runtime was shown to be substantially smaller than the data acquisition rate, which allows for performing estimation and validation of sensor measurements in real time.

Pantopoulou, Stella↗

DOE OSTI2016

Verification of the pin power reconstruction method in NESTLE

NESTLE is a 3D nodal core simulator that solves the few group neutron diffusion equation using the nodal expansion method (NEM) for the steady state (eigenvalue or fixed-source), adjoint (eigenvalue), and transient (eigenvalue or fixed-source) problems. NESTLE has been in use for over 25 years and has been continuously improved and developed. NESTLE can be used to model either Cartesian geometries (for use with typical PWR, BWR fuel assemblies) or hexagonal geometries (for use with VVER and other triangularly pitched fuel assemblies). As part of NESTLE's ongoing verification and validation process, several computational comparisons have been made to quantify the discrepancies in NESTLE's hexagonal pin power reconstruction method. In this paper, we present the results of these code-to-code comparisons and find that the root mean squared (RMS) error in pin power is comparable to other nodal codes.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗