Progress and Research Needs of Plant Biomass Degradation by Basidiomycete Fungi

Peer reviewe

Simulation of the discharge propagation in a capillary tube in air at atmospheric pressure

International audienceThis paper presents simulations of an air plasma discharge at atmospheric pressure initiated by a needle anode set inside a dielectric capillary tube. We have studied the influence of the tube inner radius and its relative permittivity ε r on the discharge structure and dynamics. As a reference, we have used a relative permittivity ε r = 1 to study only the influence of the cylindrical constraint of the tube on the discharge. For a tube radius of 100 µm and ε r = 1, we have shown that the discharge fills the tube during its propagation and is rather homogeneous behind the discharge front. When the radius of the tube is in the range 300 to 600 µm, the discharge structure is tubular with peak values of electric field and electron density close to the dielectric surface. When the radius of the tube is larger than 700 µm, the tube has no influence on the discharge which propagates axially. For a tube radius of 100 µm, when ε r increases from 1 to 10, the discharge structure becomes tubular. We have noted that the velocity of propagation of the discharge in the tube increases when the front is more homogeneous and then, the discharge velocity increases with the decrease of the tube radius and ε r. Then, we have compared the relative influence of the value of tube radius and ε r on the discharge characteristics. Our simulations indicate that the geometrical constraint of the cylindrical tube has more influence than the value of ε r on the discharge structure and dynamics. Finally, we have studied the influence of photoemission processes on the discharge structure by varying the photoemission coefficient. As expected, we have shown that photoemission, as it increases the number of secondary electrons close to the dielectric surface, promotes the tubular structure of the discharge

Determination of hydroxyl groups in biorefinery resources via quantitative 31P NMR spectroscopy

The analysis of chemical structural characteristics of biorefinery product streams (such as lignin and tannin) has advanced substantially over the past decade, with traditional wet-chemical techniques being replaced or supplemented by NMR methodologies. Quantitative 31P NMR spectroscopy is a promising technique for the analysis of hydroxyl groups because of its unique characterization capability and broad potential applicability across the biorefinery research community. This protocol describes procedures for (i) the preparation/solubilization of lignin and tannin, (ii) the phosphitylation of their hydroxyl groups, (iii) NMR acquisition details, and (iv) the ensuing data analyses and means to precisely calculate the content of the different types of hydroxyl groups. Compared with traditional wet-chemical techniques, the technique of quantitative 31P NMR spectroscopy offers unique advantages in measuring hydroxyl groups in a single spectrum with high signal resolution. The method provides complete quantitative information about the hydroxyl groups with small amounts of sample (~30 mg) within a relatively short experimental time (~30-120 min)

The unaddressed threat of invasive animals in US National Parks

Invasive species, both plants and animals, are a long-standing threat to the National Parks of the United States. For nearly two decades the National Park Service has implemented a service-wide invasive plant management program without a commensurate program focusing on invasive animals. While individual park units are struggling to sufficiently address the threat of invasive terrestrial and aquatic animal species, a system-wide effort could bring the resources and capacity needed to address a challenge of this magnitude. We present our key findings from a detailed review about invasive animal species and their management by the National Park Service. We assert that the global threat of invasive animals substantially undermines the National Park Service mission. Coordinated action could improve the ability for the National Park Service to meet the challenge, and partnering with neighboring agencies and invasive species networks outside of the National Park Service is essential for success. Public engagement, cooperation and support is also critical and can be accomplished through strategic engagement efforts. Finally, the National Park Service would benefit from the development of an invasive animal program that includes structured decision support, adaptive management and monitoring, the organizational structure to meet the highest needs, and capitalizing on the significant opportunities that exist through the appropriate use of emerging technologies