Entrar

U.S. Department of Agriculture

6 ARTICLES PUBLISHED IN JoVE

JoVE Journal

Using High Resolution Computed Tomography to Visualize the Three Dimensional Structure and Function of Plant Vasculature

Andrew J. McElrone^1,2, Brendan Choat³, Dilworth Y. Parkinson⁴, Alastair A. MacDowell⁴, Craig R. Brodersen⁵

¹U.S. Department of Agriculture, ²Department of Viticulture and Enology, University of California - Davis, ³Hawkesbury Institute for the Environment, University of Western Sydney, ⁴Advanced Light Source, Lawrence Berkeley National Lab, ⁵Citrus Research & Education Center, University of Florida

High resolution x-ray computed tomography (HRCT) is a non-destructive diagnostic imaging technique that can be used to study the structure and function of plant vasculature in 3D. We demonstrate how HRCT facilitates exploration of xylem networks across a wide range of plant tissues and species.

JoVE Journal

Surface Renewal: An Advanced Micrometeorological Method for Measuring and Processing Field-Scale Energy Flux Density Data

Andrew J. McElrone^1,2, Thomas M. Shapland², Arturo Calderon^2,3, Li Fitzmaurice^4,5, Kyaw Tha Paw U⁴, Richard L. Snyder⁴

¹Crops Pathology and Genetics Research Unit, United States Department of Agriculture-Agricultural Research Service, ²Department of Viticulture & Enology, University of California, Davis, ³Faculty of Agricultural Sciences, University of Chile, ⁴Atmospheric Science, University of California, Davis, ⁵URS Corporation Australia Pty. Ltd.

Surface renewal is a micrometeorological method that is being used increasingly to determine energy fluxes, but its technical complexity makes it inaccessible to a broad audience. We describe the steps needed to set up and calibrate a surface renewal field station, to acquire and process data, and to correctly interpret results.

Chemistry

Green and Low-cost Production of Thermally Stable and Carboxylated Cellulose Nanocrystals and Nanofibrils Using Highly Recyclable Dicarboxylic Acids

Huiyang Bian^1,3, Liheng Chen^2,3, Ruibin Wang^2,3, Junyong Zhu³

¹Jiangsu Provincial Key Lab of Pulp and Paper Science and Technology, Nanjing Forestry University, ²State Key Lab of Pulp and Paper Engineering, South China University of Technology, ³Forest Products Laboratory, U.S. Forest Service, U.S. Department of Agriculture

Here we demonstrate a novel method for green and sustainable productions of highly thermally stable and carboxylated cellulose nanocrystals (CNC) and nanofibrils (CNF) using highly recyclable solid dicarboxylic acids.

Immunology and Infection

Collection and Processing of Lymph Nodes from Large Animals for RNA Analysis: Preparing for Lymph Node Transcriptomic Studies of Large Animal Species

Catherine E. Vrentas¹, Paola M. Boggiatto¹, Robert G. Schaut¹, Steven C. Olsen¹

¹National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture

This protocol provides an overview of procedures for the isolation of RNA for the transcriptomic profiling of lymph node tissues from large animals, including steps in the identification and excision of lymph nodes from livestock and wildlife, sampling approaches to provide consistency across multiple animals, and considerations plus representative results for the post-collection preservation and processing for RNA analysis.

Environment

In Situ Soil Moisture Sensors in Undisturbed Soils

Todd G. Caldwell¹, Michael H. Cosh², Steven R. Evett³, Nathan Edwards⁴, Heather Hofman⁵, Bradley G. Illston⁶, Tilden Meyers⁷, Marina Skumanich⁸, Kent Sutcliffe⁹

¹Nevada Water Science Center, U.S. Geological Survey, ²Agricultural Research Service, Hydrology and Remote Sensing Lab., U.S. Department of Agriculture, ³Agricultural Research Service, Conservation and Production Research Lab., U.S. Department of Agriculture, ⁴South Dakota State University, ⁵National Water and Climate Center, U.S. Department of Agriculture, ⁶University of Oklahoma, ⁷Air Resources Lab, National Oceanic and Atmospheric Administration, ⁸National Integrated Drought Information System, National Oceanic and Atmospheric Administration, ⁹Snow Survey Staff, U.S. Department of Agriculture

The determination of soil water content is a critical mission requirement for many state and federal agencies. This protocol synthesizes multi-agency efforts to measure soil water content using buried in situ sensors.

Biochemistry

Non-destructive SPE-UPLC-based Quantification of Aflatoxins and Stilbenoid Phytoalexins in Single Peanut (Arachis spp.) Seeds

Victor S Sobolev¹, Renee S Arias¹, Alicia N Massa¹, Travis E Walk¹, Valerie A Orner¹, Marshall C Lamb¹

¹National Peanut Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture

We demonstrate a medium-throughput method for quantification of aflatoxins and stilbenoid phytoalexins in single peanut seeds using ultra performance liquid chromatography. This method was specifically developed for the analyses of wild Arachis species challenged by the aflatoxigenic Aspergillus species.